Plasma neurological biomarkers as a measure of neurotoxicity in pediatric dental general anesthesia: a prospective observational feasibility study

PURPOSE

Neurotoxicity concerns have been raised over general anesthesia and sedation medication use in children. Such concerns are largely based on animal studies, historical anesthetic agents, and assessment tools, thus warranting further investigations. Blood biomarkers in detecting neuronal inflammation and apoptosis are novel methods for detecting neuronal damage. Therefore, the aim of this feasibility study was to assess the usefulness of the levels of four plasma biomarkers in dental general anesthesia (DGA) as surrogate markers of neurotoxicity in children. The secondary aim was to compare changes in motor manipulative skills pre- and post-anesthetic exposure.

METHODS

This single-center prospective observational study included 22 healthy children aged between 3 and 6 years old who underwent DGA. Subclinical neurotoxicity was measured with a panel of four plasma biomarkers: Caspase-3, neuron-specific enolase (NSE), neurofilament light chain, and S100B at three time points (1; at start, 2; end and 3; on recovery from DGA). The Skillings-Mack test was used to identify the difference in the biomarker levels at three time points. Motor manipulative score assessment, prior and two weeks after DGA was also performed.

RESULTS

A total of 22 study participants (mean age = 5 ± 1 years) were included with a median DGA duration of 106 ± 28 min. A reduction in Caspase-3 levels was recorded, with pairwise comparison over three time points, reporting a statistical significance between time point 2 vs. 1 and time point 3 vs. 1. Although fluctuations in NSE levels were recorded, no significant changes were found following pairwise comparison analysis. Among other biomarkers, no significant changes over the three periods were recorded. Furthermore, no significant changes in manipulative motor scores were reported.

CONCLUSION

Caspase-3 reduced significantly in the short time frames during day-care DGA; this might be due to the relatively short anesthesia duration associated with dental treatment as compared with more extensive medical-related treatments. Therefore, further studies on Caspase-3 as a potential biomarker in pediatric DGA neurotoxicity are required to further ascertain results of this study.

Impact of fully guided implant planning software training on the knowledge acquisition and satisfaction of dental undergraduate students

BACKGROUND

A majority of dental school students do not undergo hands-on clinical training in implantology in the undergraduate curriculum. Training is usually restricted to pre-implant evaluation and post-implant prostheses. Virtual implant planning software (VIPS) provides an alternative opportunity for undergraduate students to experience implant planning much before gaining hands-on experience. However, not many studies have the contribution of VIPS to the knowledge acquisition of students. We conducted a preliminary study to evaluate the knowledge acquisition of the students when exposed to a hands-on session of VIPS. We also evaluated students' satisfaction levels, when exposed to hands-on training in fully guided implant planning software.

METHODS

A two-part theory lecture on fully guided implant planning was delivered to 90, 5th (final)-year dental undergraduate students by the oral radiology faculty. The students were then randomly divided into three groups. Group A was exposed to didactic lectures only. Group B was shown a video for fully guided implant planning in addition to the didactic lecture. Group C was shown a video for fully guided implant planning in addition to a didactic lecture and then performed a hands-on session of virtual implant planning under faculty guidance. Students from all groups were given an MCQ-based test. After the completion of the test students from group A and B also received VIPS hands-on training. Students from all three groups answered and a feedback questionnaire regarding their satisfaction levels with VIPS.

RESULTS

The overall test score of students in Group C was higher than their colleagues in both Groups A and B and the differences were statistically significant (p = 0.01). More than 85% of the students were satisfied with the teaching approach.

CONCLUSIONS

The utilization of VIPS in the training of dental undergraduate students improves their performance confirming better knowledge acquisition and content mastery.

Prevalence of anxiety, sleep bruxism and temporomandibular disorders during COVID-19 in Qatari children and adolescents: a cross-sectional study

PURPOSE

Understanding the impact of coronavirus disease-2019 (COVID-19) pandemic social restrictions on the lives of children and adolescents is of utmost importance to enable timely diagnosis and treatment. Therefore, the aim of this study was to explore the prevalence of anxiety, sleep bruxism, temporomandibular disorders (TMD) and change in dietary and brushing habits and their association with COVID-19 social restrictions.

METHODS

Parents of fit and healthy Qatari children and adolescents were recruited and interviewed by the research team, whereby validated questioners were used to assess the prevalence of children's/adolescents' anxiety, sleep bruxism and TMD. Furthermore, changes in dietary and brushing habits were also evaluated.

RESULTS

A total of 199 parents of children and adolescents (mean age = 9.3 ± 3.2 years old) were included. Overall anxiety symptoms, sleep bruxism and TMD were evident in 29.6%, 5.7% and 23.1%, respectively. An increased consumption of food, sweets and worsening of brushing habits were evident in 51.8%, 62.8% and 31.2%, respectively.

CONCLUSION

Within the limitations of this study, pandemic-related social restrictions could result in elevated levels of anxiety, specifically, social phobia, amongst children and adolescents, which could inevitably lead to unwanted dental consequences.

Deep Learning Segmentation of the Nucleus Basalis of Meynert on 3T MRI

BACKGROUND AND PURPOSE

The nucleus basalis of Meynert is a key subcortical structure that is important in arousal and cognition and has been explored as a deep brain stimulation target but is difficult to study due to its small size, variability among patients, and lack of contrast on 3T MR imaging. Thus, our goal was to establish and evaluate a deep learning network for automatic, accurate, and patient-specific segmentations with 3T MR imaging.

MATERIALS AND METHODS

Patient-specific segmentations can be produced manually; however, the nucleus basalis of Meynert is difficult to accurately segment on 3T MR imaging, with 7T being preferred. Thus, paired 3T and 7T MR imaging data sets of 21 healthy subjects were obtained. A test data set of 6 subjects was completely withheld. The nucleus was expertly segmented on 7T, providing accurate labels for the paired 3T MR imaging. An external data set of 14 patients with temporal lobe epilepsy was used to test the model on brains with neurologic disorders. A 3D-Unet convolutional neural network was constructed, and a 5-fold cross-validation was performed.

RESULTS

The novel segmentation model demonstrated significantly improved Dice coefficients over the standard probabilistic atlas for both healthy subjects (mean, 0.68 [SD, 0.10] versus 0.45 [SD, 0.11], P = .002, t test) and patients (0.64 [SD, 0.10] versus 0.37 [SD, 0.22], P < .001). Additionally, the model demonstrated significantly decreased centroid distance in patients (1.18 [SD, 0.43] mm, 3.09 [SD, 2.56] mm, P = .007).

CONCLUSIONS

We developed the first model, to our knowledge, for automatic and accurate patient-specific segmentation of the nucleus basalis of Meynert. This model may enable further study into the nucleus, impacting new treatments such as deep brain stimulation.

Analysis of inferior nasal turbinate volume in subjects with nasal septum deviation: a retrospective cone beam tomography study

Background

The association of the linear dimensions of the inferior turbinate hypertrophy with nasal septal deviation has been studied recently. However, the volumetric dimensions provide a more accurate status of the turbinate hypertrophy compared to linear measurements. The aim of this study was to analyze the association of inferior nasal turbinate volume with the degree of nasal septal deviation (NSD).

Methods

A retrospective evaluation of the cone beam computed tomography (CBCT) scans of 412 patients was carried out to obtain 150 scans which were included in the study. The scans were categorized into three groups. Group 1 comprised of 50 scans of patients with no inferior turbinate hypertrophy (ITH) and no nasal septal deviation. Group 2 comprised of 50 scans of patients with ITH and no NSD; whereas Group 3 included 50 scans of patients with ITH and NSD. The total turbinate volume of inferior turbinates (bilateral) were determined by using Vesalius 3D software (PS-Medtech, Amsterdam, Netherlands).

Results

The intraclass correlation coefficient (ICC) between the volumetric estimations performed by the two radiologists was 0.82. There were no significant age and gender related changes in the total turbinate volume. Patients in Group 3 had significantly higher (p = 0.001) total turbinate volume compared to Group 2 and Group 1. There was a positive and significant correlation (r = 0.52, p = 0.002) between the degree of septal deviation and total turbinate volume. When the total turbinate volume of the patients with different types of septal deviation was compared in Group 3, a statistically significant difference (p = 0.001) was observed. Regression analysis revealed that the septal deviation angle (SDA) (p = 0.001) had a relationship with total turbinate volume. From the results of the study we can conclude that the total turbinate volume is higher in patients with nasal septal deviation. It can also be concluded that the septal deviation angle has a positive correlation with total turbinate volume. The data obtained from the study can be useful in post-surgical follow up and evaluation of patients with nasal septal deviation and hypertrophied inferior nasal turbinate.

The effect of concha bullosa and nasal septal deviation on palatal dimensions: a cone beam computed tomography study

Introduction

Nasal septal deviation (NSD) and concha bullosa (CB) are associated with airway obstruction in mouth breathers. Mouth breathing is associated with alterations in maxillary growth and palatal architecture. The aim of our study was to determine the effect of the presence of CB and NSD on the dimensions of the hard palate using cone-beam computed tomography (CBCT).

Materials and methods

A retrospective study was conducted using CBCT scans of 200 study subjects. The study subjects were divided into four groups based on the presence of CB and NSD. Septal deviation angle (SDA), palatal interalveolar length (PIL), palatal depth (PD) and maxillopalatal arch angle (MPAA) were measured in the study groups.

Results

The presence of NSD and CB was associated with significant (p < 0.001) differences in the palatal dimensions of the study subjects. The PIL and MPA (p < 0.001) were significantly reduced (p < 0.001), whereas the PD was significantly increased (p < 0.001) in study subjects with NSD and CB. There was no significant change in the palatal dimensions between the unilateral and bilateral types of CB. Among the palatal dimensions, the PIL had the most significant association (R² = 0.53) with SDA and CB. There was a significant correlation between the palatal dimensions and SDA when CB was present along with NSD.

Conclusion

Based on the results of this study, it can be concluded that the presence of NSD and CB have a significant effect on the palatal dimensions and, therefore, they may be associated with skeletal malocclusion.

Large cemento-ossifying fibroma of the mandible involving the infratemporal and parapharyngeal spaces

Cemento-ossifying fibroma is a benign fibro-osseous lesion of the jaws. Cemento-ossifying fibroma develops from the periodontal ligament and contains multipotent stem cells that can form cementum, lamellar bone, and/or fibrous tissue. These tumours occur in the third and fourth decades of life with higher predilection of occurrence in the female population and seldom attain a large size. We report a rare case of cemento-ossifying fibroma in a 45-year-old man involving the body of the mandible and extending into the para-pharyngeal and infratemporal region. This article describes the clinical, radiographic, and histological features of a large cemento-ossifying fibroma of the mandible.

A University-based Survey of Career Choices and Perspectives on Higher Education among Dental Students in United Arab Emirates

Background:

Over the past decade, higher education has made significant progress in the Gulf Corporation Council Region (GCC) due to the promotion and investments made by the local governments. Medical and dental higher education has undergone massive transformation across all the universities in the United Arab Emirates (UAE) due to the implementation of innovative educational policies.

Objectives:

The objective of the survey was to determine the career choices and assess the perspectives on higher education among dental students of a medical university in the UAE.

Methodology:

Structured closed-ended survey questionnaire was provided to 377 respondents at a dental school of a private medical university in UAE.

Results:

The results of the survey revealed that 51% of the respondents wanted to pursue specialization in dentistry. Orthodontics (33%), endodontics (28%) and oral surgery (16%) were the most preferred branches for specialization. UAE was the most preferred destination for pursuing specialization. Quality of education and proximity to the family were the most common reasons for selecting UAE as the destination for specialization. 36% of the survey respondents wanted more dental post-graduate seats to be available in the UAE. 57% of the survey respondents felt that the cost of post-graduation is comparable to other countries. 64% of the survey respondents felt that Doctor of Philosophy(PhD) program should be offered by medical universities in the UAE.

Conclusion:

To conclude it can be stated that dental undergraduate students in the UAE prefer to pursue specialization in clinical branches like orthodontics, endodontics and oral surgery. Majority of the respondents prefer to pursue their specialization in the UAE due to the quality of education. Survey respondents felt that there was a need to offer more dental post-graduation and dental PhD programs by UAE universities.

Analysis of inferior nasal turbinate width and concha bullosa in subjects with nasal septum deviation: a cone beam tomography study

Background

In individuals with nasal septal deviation (NSD), compensatory hypertrophy of the nasal turbinates occurs as a protective mechanism of the nasal passage from dry and cold air. NSD associated nasal turbinate hypertrophy is usually recurrent, requiring repetitive imaging. Therefore, a multiplanar imaging modality with a low radiation dose is best suited for long-term follow-up of this condition. This study aimed to evaluate the association of width of inferior turbinates and presence of concha bullosa with the degree of NSD using Cone beam computed tomography (CT).

Methods

The CBCT scans of 100 patients with NSD were selected as per convenience sampling and were evaluated by two maxillofacial radiologists. The width of the non-hypertrophied inferior turbinate (NHT) on the convex side of the NSD, and hypertrophic inferior turbinates (HT) on the concave side of the NSD were measured at three locations. The septal deviation angle (SDA) and the presence of concha bullosa (CB) were determined.

Results

A significant difference was observed in the anterior, middle, posterior, and mean widths between HT and NHT (p < 0.001). There was a significant difference in the widths of the HT and NHT among different types of NSD. A strong positive correlation (r = 0.71, p < 0.001) was found between SDA and the mean width of the HT. Age (P = 0.71) and gender (P = 0.65) had no significant difference among different types of NSD. Regression analysis revealed that the presence of CB (p = 0.01) and middle width of the HT (p < 0.001) are significant predictors of SDA and type of NSD.

Conclusion

The results of the present study reveal that the middle width of the HT and the presence of CB influence the degree of NSD. The present study results recommend the use of CBCT as a substitutive low radiation dose imaging modality for evaluation of NSD, CB, and associated inferior turbinate hypertrophy.

Nosocomial COVID-19: experience from a large acute NHS Trust in South-West London

Transmission of coronavirus disease 2019 (COVID-19) in healthcare settings has significant implications for patients and healthcare workers, may amplify local outbreaks, and may place additional burden on already stretched resources. Risk of missed or late diagnosis of COVID-19 was high during the UK's initial 'containment phase', because of strict criteria for testing. The risk remains due to asymptomatic/pre-symptomatic transmission, complicated by challenges faced with laboratory testing. We present a case study of potential nosocomial transmission associated with the first case of COVID-19 at a large acute NHS Trust in South-West London, and we describe the prevailing burden of nosocomial infections.

Adoption of direct oral anticoagulants for stroke prevention in atrial fibrillation

BACKGROUND

Direct oral anticoagulants (DOAC) are being increasingly utilised for stroke prevention in atrial fibrillation (AF) and atrial flutter.

AIMS

To analyse the adoption and application of these drugs in a regional hospital inpatient cohort and compare with national prescribing data.

METHODS

Digital medical records identified prescribed anticoagulants for patients admitted with AF and atrial flutter during 2013-2014. Analysis of patient demographics and stroke risk identified trends in prescribing DOAC versus warfarin. For broader comparison, data from the Pharmaceuticals Benefits Scheme were sourced to determine the nation-wide adoption of DOAC.

RESULT

Of the 615 patients identified, 505 (255 in 2013, 250 in 2014) had sufficient records to include in the study. From 2013 to 2014, DOAC prescriptions increased from 9 to 28% (P < 0.001), warfarin and aspirin remained comparatively stable (38-34%, 22-20%), and those prescribed no medication declined (17-8%, P < 0.001). DOAC were prescribed to patients with lower CHA2 DS2 VASc scores than warfarin (3.6 vs 4.4; P = 0.005), lower HAS-BLED scores (1.7 vs 2.3; P < 0.01), higher glomerular filtration rates; 70 vs 63 ml/min; P = 0.002) and younger age (74 vs 77 years; P = 0.006). Nationally, warfarin prescriptions are higher in total numbers but increasing at a slower rate than DOAC, which increased 10-fold (101 158 in 2013, 1 095 985 in 2014).

CONCLUSION

DOAC prescribing grew rapidly from 2013 to 2014, regionally and nationally. Warfarin prescriptions have remained stable, indicating that more patients are being appropriately anticoagulated for AF who previously were not. DOAC were found to be prescribed to patients with lower CHA2 DS2 VASc and HAS-BLED scores, younger age and higher glomerular filtration rates. Aspirin therapy remains over utilised in AF.

Surgical Management of a Rare Case of Massive Compound Odontome Associated with Missing Primary Tooth

Odontomes are considered to be the most common odontogenic tumours of the jaws. They are benign, mixed tumours arising from the remnants of both odontogenic epithelium and the ectomesenchyme resulting in the deposition of varied propotions of enamel, dentin, cementum and pulp tissues. As these lesions show deficiency only in structural arrangement, some authors consider odontomes as hamartomas or tumour like malformations. Though these lesions are more common in children, very few cases have been reported in less than five years age group. Blood loss is a major issue in paediatric surgery. Careful and safe surgery is the primary goal of the surgeon. The external carorid artery which is the only feeder of blood to the face and oral cavity can be ligated to control bleeding in extensive maxillofacial injuries and orofacial malignancies. Herewith, we report a massive odontome in a three and half-year-old child which was treated by surgical excision along with carotid control to prevent excess bleeding.

Crystal structures of (E)-4-[1-(2-carbamo-thio-yl-hydrazinyl-idene)eth-yl]phenyl acetate and (E)-4-[1-(2-carbamo-thio-ylhydrazinyl-idene)eth-yl]phenyl benzoate

In the title compounds, C11H13N3O2S, (I), and C16H15N3O2S, (II), the thio-semicarbazone group adopts an extended conformation. The acetate ester (I) crystallizes with two independent mol-ecules in the asymmetric unit. In the benzoate ester (II), the planes of the two aryl rings are inclined to one another by 46.70 (7)°. In both compounds, there is a short intra-molecular N-H⋯N contact present, forming an S(5) ring motif. In the crystals of both compounds, mol-ecules are linked via pairs of N-H⋯S hydrogen bonds, forming dimers with R22(8) ring motifs. The dimers are linked by N-H⋯S and N-H⋯O hydrogen bonds, forming slabs parallel to (01-1). In (I), there are N-H⋯π and C-H⋯π inter-actions present within the slabs, while in (II), there are only N-H⋯π inter-actions present.

Sense and simplicity in HADDOCK scoring: Lessons from CASP-CAPRI round 1

Our information-driven docking approach HADDOCK is a consistent top predictor and scorer since the start of its participation in the CAPRI community-wide experiment. This sustained performance is due, in part, to its ability to integrate experimental data and/or bioinformatics information into the modelling process, and also to the overall robustness of the scoring function used to assess and rank the predictions. In the CASP-CAPRI Round 1 scoring experiment we successfully selected acceptable/medium quality models for 18/14 of the 25 targets - a top-ranking performance among all scorers. Considering that for only 20 targets acceptable models were generated by the community, our effective success rate reaches as high as 90% (18/20). This was achieved using the standard HADDOCK scoring function, which, thirteen years after its original publication, still consists of a simple linear combination of intermolecular van der Waals and Coulomb electrostatics energies and an empirically derived desolvation energy term. Despite its simplicity, this scoring function makes sense from a physico-chemical perspective, encoding key aspects of biomolecular recognition. In addition to its success in the scoring experiment, the HADDOCK server takes the first place in the server prediction category, with 16 successful predictions. Much like our scoring protocol, because of the limited time per target, the predictions relied mainly on either an ab initio center-of-mass and symmetry restrained protocol, or on a template-based approach whenever applicable. These results underline the success of our simple but sensible prediction and scoring scheme. Proteins 2017; 85:417-423. © 2016 Wiley Periodicals, Inc.

Rapid rule out of myocardial infarction with the use of copeptin as a biomarker for cardiac injury

Copeptin is a non-specific marker of an endogenous stress response. A dual biomarker marker approach involving the simultaneous use of troponin and copeptin assays may assist early exclusion of acute coronary syndrome in Australian emergency departments. The utility and limitations of this approach are discussed.

Crystal structure of (E)-4-{1-[2-(car-bamo-thio-yl)hydrazin-1-yl-idene]ethyl}phenyl 4-methyl-benzoate

The asymmetric unit of the title compound, C₁₇H₁₇N₃O₂S, consists of two independent mol­ecules, A and B, with different conformations: in mol­ecule A, the dihedral angles between the central benzene ring and the pendant tolyl and carbamo­thio­ylhydrazono groups are 71.12 (9) and 5.95 (8)°, respectively. The corresponding angles in mol­ecule B are 50.56 (12) and 26.43 (11)°, respectively. Both mol­ecules feature an intra­molecular N—H⋯N hydrogen bond, which closes an S(5) ring. In the crystal, mol­ecules are linked by N—H⋯O, N—H⋯S and C—H⋯O hydrogen bonds, generating a three-dimensional network.

Crystal structure of 4-acetyl-phenyl 3-methyl-benzoate

The planes of the aromatic rings of the title compound, C₁₆H₁₄O₃, make a dihedral angle of 82.52 (8)°. The acetyl group and the phenyl ring make a dihedral angle of 1.65 (1)°. In the crystal, the molecules are linked by C—H⋯O interactions, generating C(7) chains along the a-axis direction.

4-Bromo-2-(diethoxymethyl)phenyl benzoate

In the title compound, C₁₈H₁₉BrO₄, the aromatic rings enclose a dihedral angle of 81.9 (7)°. There are no short directional contacts in the crystal structure.

Diethyl 2,6-dimethyl-4-[4-(3-phenyl-acrylo-yloxy)phen-yl]-1,4-dihydro-pyridine-3,5-dicarboxyl-ate hemihydrate

In the title ester derivative, C28H29NO6·0.5H2O, the 1,4-dihydro-pyridine ring has a flattened boat conformation. The mean plane is almost perpendicular to the attached benzene ring, making a dihedral angle of 86.87 (9)°. The terminal phenyl ring is inclined to the central benzene ring by 67.56 (12)°. In the crystal, mol-ecules are bridged via O-H⋯O hydrogen bonds involving the partially occupied water mol-ecule, and this arrangement is strengthened by a pair of N-H⋯O hydrogen bonds and C-H⋯O inter-actions. The ethyl atoms of one of the ethyl ester groups are disordered over two sites with an occupancy ratio of 0.716 (5):0.284 (5).

2-Bromo-4-tert-butyl-6-[(pyridin-2-ylimino)methyl]phenol

In the title compound, C₁₆H₁₇BrN₂O, the pyridine and benzene rings are almost coplanar [dihedral angle = 1.3 (2)°]. An intra­molecular O—H⋯Br inter­action forms an S(5) ring motif.

Evalution of anti-ulcer activity of Polyalthia longifolia (Sonn.) Thwaites in experimental animals

Objective:

To evaluate the anti-ulcer activity of ethanol extract of leaves of Polyalthia longifolia (Sonn.) Thwaites.

Materials and Methods:

The ethanol extract of Polyalthia longifolia was investigated for its anti-ulcer activity against aspirin plus pylorous ligation induced gastric ulcer in rats, HCl -Ethanol induced ulcer in mice and water immersion stress induced ulcer in rats at 300 mg/kg body weight.p.o.

Results:

A significant (P < 0.01, P < 0.001) anti ulcer activity was observed in all the models. Pylorous ligation showed significant (P< 0.01) reduction in gastric volume, free acidity and ulcer index as compared to control. It also showed 89.71% ulcer inhibition in HCl- Ethanol induced ulcer and 95.3% ulcer protection index in stress induced ulcer.

Conclusion:

This present study indicates that P. longifolia leaves extract have potential anti ulcer activity in the three models tested.

Ultra-low-power and robust digital-signal-processing hardware for implantable neural interface microsystems

Implantable microsystems for monitoring or manipulating brain activity typically require on-chip real-time processing of multichannel neural data using ultra low-power, miniaturized electronics. In this paper, we propose an integrated-circuit/architecture-level hardware design framework for neural signal processing that exploits the nature of the signal-processing algorithm. First, we consider different power reduction techniques and compare the energy efficiency between the ultra-low frequency subthreshold and conventional superthreshold design. We show that the superthreshold design operating at a much higher frequency can achieve comparable energy dissipation by taking advantage of extensive power gating. It also provides significantly higher robustness of operation and yield under large process variations. Next, we propose an architecture level preferential design approach for further energy reduction by isolating the critical computation blocks (with respect to the quality of the output signal) and assigning them higher delay margins compared to the noncritical ones. Possible delay failures under parameter variations are confined to the noncritical components, allowing graceful degradation in quality under voltage scaling. Simulation results using prerecorded neural data from the sea-slug (Aplysia californica) show that the application of the proposed design approach can lead to significant improvement in total energy, without compromising the output signal quality under process variations, compared to conventional design approaches.

Synthesis of cytotoxic and antioxidant Schiff's base analogs of aloin

Aloin (10-glucopyranosyl-1,8-dihydroxy-3-hydroxymethyl-9(10H)-anthracenone), a bioactive compound in Aloe vera, although known to have an anticancer effect, has not been used in current drug research. Optimization of the lead structure could enhance the utility of this compound. Hence, aloin was modified using natural amino acids to produce Schiff's base, a potential pharmacophore, and its corresponding aglycones. The synthetic derivatives exhibited significant enhancement in their efficacy toward antioxidant (DPPH radical scavenging) and cytotoxic activities than those of the parent compound, aloin showing promise for application in cancer treatment.

5-Meth-oxy-2,2-dimethyl-6-[(2E)-2-methyl-but-2-eno-yl]-10-phenyl-2H,8H-pyrano[2,3-f]chromen-8-one (calophyllolide)

The title compound, C₂₆H₂₄O₅, was isolated from calophyllum inophyllum seeds. In the mol­ecule, the phenyl and 2-methyl­but-2-enoyl groups are almost orthogonal to the chromene fragment [C—C—C—C torsion angles = 81.4 (3) and −90.1 (2)°, respectively]. In the crystal packing, centrosymmetrically related mol­ecules are linked by C—H⋯O contacts into dimers, which are connected via further C—H⋯O inter­actions into a double chain along [010].

Diverse roles for protein kinase C delta and protein kinase C epsilon in the generation of high-fat-diet-induced glucose intolerance in mice: regulation of lipogenesis by protein kinase C delta

AIMS/HYPOTHESIS

This study aimed to determine whether protein kinase C (PKC) delta plays a role in the glucose intolerance caused by a high-fat diet, and whether it could compensate for loss of PKCepsilon in the generation of insulin resistance in skeletal muscle.

METHODS

Prkcd (-/-), Prkce (-/-) and wild-type mice were fed high-fat diets and subjected to glucose tolerance tests. Blood glucose levels and insulin responses were determined during the tests. Insulin signalling in liver and muscle was assessed after acute in vivo insulin stimulation by immunoblotting with phospho-specific antibodies. Activation of PKC isoforms in muscle from Prkce (-/-) mice was assessed by determining intracellular distribution. Tissues and plasma were assayed for triacylglycerol accumulation, and hepatic production of lipogenic enzymes was determined by immunoblotting.

RESULTS

Both Prkcd (-/-) and Prkce (-/-) mice were protected against high-fat-diet-induced glucose intolerance. In Prkce (-/-) mice this was mediated through enhanced insulin availability, while in Prkcd (-/-) mice the reversal occurred in the absence of elevated insulin. Neither the high-fat diet nor Prkcd deletion affected maximal insulin signalling. The activation of PKCdelta in muscle from fat-fed mice was enhanced by Prkce deletion. PKCdelta-deficient mice exhibited reduced liver triacylglycerol accumulation and diminished production of lipogenic enzymes.

CONCLUSIONS/INTERPRETATION

Deletion of genes encoding isoforms of PKC can improve glucose intolerance, either by enhancing insulin availability in the case of Prkce, or by reducing lipid accumulation in the case of Prkcd. The absence of PKCepsilon in muscle may be compensated by increased activation of PKCdelta in fat-fed mice, suggesting that an additional role for PKCepsilon in this tissue is masked.