Quinoline, Indole, and Isogranatanine Alkaloids from Malayan Leuconotis eugeniifolia

Nine new alkaloids, eugeniinalines A-H (1-8) and (+)-eburnamenine N-oxide (9), comprising one quinoline, six indole, and two isogranatanine alkaloids, were isolated from the stem-bark extract of the Malayan Leuconotis eugeniifolia. The structures and absolute configurations of these alkaloids were established based on the analysis of the spectroscopic data, GIAO NMR calculations, DP4+ probability analysis, TDDFT-ECD method, and X-ray diffraction analysis. Eugeniinaline A (1) represents a new pentacyclic quinoline alkaloid with a 6/6/5/6/7 ring system. Eugeniinaline G (7) and its seco-derivative, eugeniinaline H (8), were the first isogranatanine alkaloids isolated as natural products. The known alkaloids leucolusine (10) and melokhanine A (11) were found to be the same compound, based on comparison of the spectroscopic data of both compounds, with the absolute configuration of (7R, 20R, 21S). Eugeniinalines A and G (1 and 7) showed cytotoxic activity against the HT-29 cancer cell line with IC50 values of 7.1 and 7.2 μM, respectively.

Polyneurines A-H, iboga alkaloids from Tabernaemontana polyneura

Eight undescribed iboga alkaloids, polyneurines A-H, were isolated from the bark of Tabernaemontana polyneura. The structures of these alkaloids were established by interpretation of the MS and NMR data, while the configurations were determined using GIAO NMR calculations and DP4+ probability analysis, TDDFT-ECD method, or X-ray diffraction analysis. Polyneurine A possesses a γ-lactone unit embedded within the iboga skeleton, while polyneurines D and E incorporate a formylmethyl moiety at C-3 of the iboga skeleton. Biosynthetic pathways towards the formation of polyneurines A, C, D, and E were proposed.

630 Hailey-Hailey Disease: A Rare Presentation in the Hypopharnyx

Background

Hailey-Hailey disease or familial benign pemphigus is a rare genetic blistering skin disease due to mutation of the ATP2C1 gene inherited in autosomal dominant fashion. Prevalence is around 1 in 50,000 and positive family history is observed in 75% of cases. Patients typically present with well-demarcated painful erosive and yellow-crusted rash in the skin folds, following a relapsing-remitting pattern. There are very limited known cases of extra-dermatological presentation of this disease.

Case

64-year-old gentleman presented with dysphagia, hoarseness, sore throat, dry cough, and intermittent haemoptysis. Initial flexible nasendoscopy showed mild erythema of epiglottis and false cords, post-cricoid oedema and very mild Reinke's oedema. He was treated as acid reflux with omeprazole but to little effect. Endoscopy 4 months later showed similar findings hence biopsy of the hypopharynx was taken. The sample demonstrated intraepithelial clefting, suspicious of intraepithelial vesiculobullous disorder particularly pemphigus vulgaris.

Looking into this gentleman's medical history, it was found that he is under the care of dermatology for Hailey-Hailey disease, which he was diagnosed 30 years ago. He also has a strong family history of this condition. Based on the biopsy findings and patient profile, it was concluded that this gentleman has a hypopharyngeal manifestation of Hailey-Hailey disease.

Discussion

Hailey-Hailey disease is traditionally described as a dermatological condition. This gentleman is one of the rare few cases of non-dermatological manifestation of this disease.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Fabrication of infrared linear arrays of InAs planar avalanche photodiodes

We report a, to the best of our knowledge, new device fabrication process for 128-pixel linear arrays of InAs planar avalanche photodiodes, utilizing selective area implantation of Beryllium ions into epitaxially-grown InAs wafers. The pixels exhibited uniform avalanche gain and responsivity. Room temperature responsivity values at 1550 and 2004 nm wavelengths are 0.49 ± 0.017 and 0.89 ± 0.024 A/W, respectively. Reverse dark current-voltage and avalanche gain measurements were carried out at different temperatures (from room temperature to 150 K). At 200 K at -15 V reverse bias, the pixels exhibited an avalanche gain of 22.5 ± 1.18 and dark current density of 0.68 ± 0.48 A/cm².

Simulation of Al0.85Ga0.15As0.56Sb0.44 avalanche photodiodes

Al_0.85Ga_0.15As_0.56Sb_0.44 is a promising avalanche material for near infrared avalanche photodiodes (APDs) because they exhibit very low excess noise factors. However electric field dependence of ionization coefficients in this material have not been reported. We report a Simple Monte Carlo model for Al_0.85Ga_0.15As_0.56Sb_0.44, which was validated using reported experimental results of capacitance-voltage, avalanche multiplication and excess noise factors from five APDs. The model was used to produce effective ionization coefficients and threshold energies between 400-1200 kV.cm^-1 at room temperature, which are suitable for use with less complex APD simulation models.

A network meta-analysis on the vasomodulators for portopulmonary hypertension

Background

In patients with portopulmonary hypertension (PoPH) who are eligible and awaiting liver transplant, guidelines recommend lowering pulmonary pressures with vasomodulators as a bridge to transplant. However, efficacy of each vasomodulator class as a bridge to transplant remains unknown.

Purpose

This review compares the use of endothelin receptor antagonists (ERA), phosphodiesterase type-5 inhibitors (PDE5-I), prostacyclin (PC) and combination therapy in its pulmonary pressure-lowering effects and pre-transplant mortality in this strictly selected subset of patients.

Methods

A search conducted on Medline and Embase on articles relating to vasomodulator use in PoPH for pulmonary pressure-lowering effects and mortality. Network analysis was conducted to summarize the evidence. Surface under the cumulative ranking curve (SUCRA) was used to rank treatments.

Results

Ten studies with 180 patients were included. SUCRA analysis demonstrated largest mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) lowering effects in ERA and combination therapy, followed by PDE5-I and PC. mPAP-lowering effects were largest in ERA (MD −19.440, CI: −62.280 to 23.400) and combination therapy (MD −18.223, CI: −29.677 to −6.770) when compared to PDE5-I (table 1). Pre-transplant mortality were comparable between ERA, PDE5-I and combination therapy. Both ERA (RR:0.349. CI: 0.137–0.891) and PDE5-I (RR: 0.279, CI: 0.091–0.854) had significantly lower mortality than PC (table 2).

Conclusion

This meta-analysis provides preliminary evidence that ERA have shown larger pulmonary pressure-lowering effects than PDE5-I in PoPH patients who were eligible for LT. Both ERA and PDE5-I have comparable mortality outcomes, with unfavorable outcomes in PC users.

Funding Acknowledgement

Type of funding sources: None.

The Bisindole Alkaloids Angustilongines M and A from Alstonia penangiana Induce Mitochondrial Apoptosis and G0/G1 Cell Cycle Arrest in HT-29 Cells through Promotion of Tubulin Polymerization

A new linearly fused macroline-sarpagine bisindole, angustilongine M (1), was isolated from the methanolic extract of Alstonia penangiana. The structure of the alkaloid was elucidated based on analysis of the spectroscopic data, and its biological activity was evaluated together with another previously reported macroline-akuammiline bisindole from the same plant, angustilongine A (2). Compounds 1 and 2 showed pronounced in vitro growth inhibitory activity against a wide panel of human cancer cell lines. In particular, the two compounds showed potent and selective antiproliferative activity against HT-29 cells, as well as strong growth inhibitory effects against HT-29 spheroids. Cell death mechanistic studies revealed that the compounds induced mitochondrial apoptosis and G0/G1 cell cycle arrest in HT-29 cells in a time-dependent manner, while in vitro tubulin polymerization assays and molecular docking analysis showed that the compounds are microtubule-stabilizing agents, which are predicted to bind at the β-tubulin subunit at the Taxol-binding site.

Macroline, talpinine, and sarpagine alkaloids from Alstonia penangiana. An NMR-based method for differentiating between A. penangiana and A. macrophylla

Fourteen previously undescribed alkaloids comprising two N-1-hydroxymethylmacroline alkaloids, one talpinine-type oxindole acetal, a pair of equilibrating talpinine-type oxindole hemiacetals, eight oxidized derivatives of sarpagine- and akuammiline-type indole alkaloids, in addition to alstochalotine a diastereomer of gelsochalotine recently isolated from Gelsemium elegans, were isolated from the leaf and stem-bark extracts of Alstonia penangiana. The structures and relative configurations of these alkaloids were established using NMR, MS, and in one instance, confirmed by X-ray diffraction analysis. An NMR-based method is described as a useful chemotaxonomic tool for differentiating between A. penangiana and A. macrophylla. Several of the alkaloids isolated showed appreciable growth inhibitory effects when tested against a number of human cancer cell lines.

Macroline-Sarpagine Bisindole Alkaloids with Antiproliferative Activity from Alstonia penangiana

A methanol extract of the stem bark of the Malayan Alstonia penangiana provided seven new bisindole alkaloids, comprising six macroline-sarpagine alkaloids (angustilongines E-K, 1-6) and one macroline-pleiocarpamine bisindole alkaloid (angustilongine L, 7). Analysis of the spectroscopic data (NMR and MS) of these compounds led to the proposed structures of these alkaloids. The macroline-sarpagine alkaloids (1-6) showed in vitro growth inhibitory activity against a panel of human cancer cell lines, inclusive of KB, vincristine-resistant KB, PC-3, LNCaP, MCF7, MDA-MB-231, HT-29, HCT 116, and A549 cells (IC₅₀ values: 0.02-9.0 μM).

Analysis of Bi Distribution in Epitaxial GaAsBi by Aberration-Corrected HAADF-STEM

The Bi content in GaAs/GaAs_1 - xBi _x /GaAs heterostructures grown by molecular beam epitaxy at a substrate temperature close to 340 °C is investigated by aberration-corrected high-angle annular dark-field techniques. The analysis at low magnification of high-angle annular dark-field scanning transmission electron microscopy images, corroborated by EDX analysis, revealed planar defect-free layers and a non-homogeneous Bi distribution at the interfaces and within the GaAsBi layer. At high magnification, the qHAADF analysis confirmed the inhomogeneous distribution and Bi segregation at the GaAsBi/GaAs interface at low Bi flux and distorted dumbbell shape in areas with higher Bi content. At higher Bi flux, the size of the Bi gathering increases leading to roughly equiaxial Bi-rich particles faceted along zinc blende {111} and uniformly dispersed around the matrix and interfaces. FFT analysis checks the coexistence of two phases in some clusters: a rhombohedral pure Bi (rh-Bi) one surrounded by a zinc blende GaAs_1 - xBi _x matrix. Clusters may be affecting to the local lattice relaxation and leading to a partially relaxed GaAsBi/GaAs system, in good agreement with XRD analysis.

Water as neutral oral contrast agent in abdominopelvic CT: comparing effectiveness with Gastrografin in the same patient

INTRODUCTION

Positive oral contrast is no longer deemed necessary for abdominopelvic computed tomography (CT) scans. Studies have shown water to be an equally effective oral contrast agent. However, to our knowledge no study has compared effectiveness between gastrografin and water in the same patient, which will provide a more objective evaluation of the two oral contrast agents. We aim to make a head-to-head comparison of water as neutral oral contrast (OC) against gastrografin as positive OC for abdominopelvic CT scans in the same patient.

METHODS

A retrospective review of 206 abdominopelvic CT scans of 103 patients was performed. The scans were reviewed in consensus by two blinded radiologists. The ability to visualise each abdominopelvic organ, contrastassociated artefacts and small bowel wall delineation, was qualitatively scored on a 5-point scale. Each patient had two sets of scores, one with water and another with gastrografin as OC. Paired scores from the two OCs were evaluated by Wilcoxon signed rank test to determine any significant difference in performance between the two OCs for visualisation of abdominopelvic anatomy on CT.

RESULTS

There was significantly better delineation of duodenal wall (p<0.001) and overall visualisation of the duodenum (p=0.011) using water as OC compared to gastrografin. No statistically significant differences were demonstrated between water and gastrografin for visualisation of the rest of the abdominopelvic organs, walldelineation of the rest small bowel and contrast-associated artefacts.

CONCLUSIONS

Water can be used in place of gastrografin as oral contrast in abdominopelvic CT without compromising visualization of abdominopelvic organs.

A hybrid approach for fusing 4D-MRI temporal information with 3D-CT for the study of lung and lung tumor motion

PURPOSE

Accurate visualization of lung motion is important in many clinical applications, such as radiotherapy of lung cancer. Advancement in imaging modalities [e.g., computed tomography (CT) and MRI] has allowed dynamic imaging of lung and lung tumor motion. However, each imaging modality has its advantages and disadvantages. The study presented in this paper aims at generating synthetic 4D-CT dataset for lung cancer patients by combining both continuous three-dimensional (3D) motion captured by 4D-MRI and the high spatial resolution captured by CT using the authors' proposed approach.

METHODS

A novel hybrid approach based on deformable image registration (DIR) and finite element method simulation was developed to fuse a static 3D-CT volume (acquired under breath-hold) and the 3D motion information extracted from 4D-MRI dataset, creating a synthetic 4D-CT dataset.

RESULTS

The study focuses on imaging of lung and lung tumor. Comparing the synthetic 4D-CT dataset with the acquired 4D-CT dataset of six lung cancer patients based on 420 landmarks, accurate results (average error <2 mm) were achieved using the authors' proposed approach. Their hybrid approach achieved a 40% error reduction (based on landmarks assessment) over using only DIR techniques.

CONCLUSIONS

The synthetic 4D-CT dataset generated has high spatial resolution, has excellent lung details, and is able to show movement of lung and lung tumor over multiple breathing cycles.

Prescribing Pattern of Antidepressants in Children and Adolescents: Findings from the Research on Asia Psychotropic Prescription Pattern

OBJECTIVE

Pharmacotherapy of depression in children and adolescents is complex. In the absence of research into the efficacy and safety of antidepressants in this group of patients, their off-label prescription is common. This paper aimed to illustrate the prescription pattern of antidepressants in children and adolescents from major psychiatric centres in Asia.

METHODS

The Research on Asia Psychotropic Prescription Pattern on Antidepressants worked collaboratively in 2013 to study the prescription pattern of antidepressants in Asia using a unified research protocol and questionnaire. Forty psychiatric centres from 10 Asian countries / regions participated and 2321 antidepressant prescriptions were analysed.

RESULTS

A total of 4.7% antidepressant prescriptions were for children and adolescents. Fluoxetine, sertraline, and escitalopram were the most common antidepressants prescribed for children and adolescents. Almost one-third (30.3%) of prescriptions were for diagnoses other than depressive and anxiety disorders. There was less antidepressant polypharmacy and concomitant use of benzodiazepine, but more concomitant use of antipsychotics in children and adolescents compared with adults.

CONCLUSION

Off-label use of antidepressants in children and adolescents was reported by 40 Asian psychiatric institutions that participated in the study. In-service education and regulatory mechanisms should be reinforced to ensure efficacy and safety of antidepressants in children and adolescents.

Sex-specific differences in risk factors for sarcopenia amongst community-dwelling older adults

With considerable variation including potential sex-specific differential rate of skeletal muscle loss, identifying modifiable factors for sarcopenia will be pivotal to guide targeted interventions. This study seeks to identify clinical and biological correlates of sarcopenia in community-dwelling older adults, with emphasis on the role of anabolic and catabolic stimuli, and special reference to gender specificity. In this cross-sectional study involving 200 community-dwelling and functionally independent older adults aged ≥50 years, sarcopenia was defined using the Asian Working Group for Sarcopenia criteria. Comorbidities, cognitive and functional performance, physical activity and nutritional status were routinely assessed. Biochemical parameters included haematological indices, lipid panel, vitamin D level, anabolic hormones [insulin-like growth factor-1 (IGF-1), free testosterone (males only)] and catabolic markers [inflammatory markers (interleukin-6, C-reactive protein) and myostatin]. Multiple logistic regression was performed to identify independent predictors for sarcopenia. Age was associated with sarcopenia in both genders. Malnutrition conferred significantly higher odds for sarcopenia in women (OR = 5.71, 95% CI 1.13-28.84.44, p = 0.035) while higher but acceptable range serum triglyceride was protective in men (OR = 0.05, 95% CI 0.00-0.52, p = 0.012). Higher serum myostatin independently associated with higher odds for sarcopenia in men (OR = 1.11, 95% CI 1.00-1.24, p = 0.041). Serum IGF-1 was significantly lower amongst female sarcopenic subjects, with demonstrable trend for protective effect against sarcopenia in multiple regression models, such that each 1 ng/ml increase in IGF-1 was associated with 1% decline in odds of sarcopenia in women (p = 0.095). Our findings support differential pathophysiological mechanisms for sarcopenia that, if corroborated, may have clinical utility in guiding sex-specific targeted interventions for community-dwelling older adults.

Antidepressant Prescription Pattern in the Presence of Medical Co-morbidity: REAP-AD 2013 Study

OBJECTIVE

To evaluate the prescription pattern of antidepressants in patients with medical co-morbidity from major psychiatric centres in Asia.

METHODS

The Research on Asian Psychotropic Prescription Pattern for Antidepressants (REAP-AD 2013) collected data from 42 psychiatric centres in 10 Asian countries and regions. Antidepressant prescriptions of 2320 patients with various psychiatric disorders were evaluated. Of these, 370 patients who had specified medical co-morbidities formed the study cohort.

RESULTS

Escitalopram (20%) and mirtazapine (20%) were the most commonly prescribed antidepressants in patients with medical co-morbidity followed by sertraline (16%), trazodone (15%), and paroxetine (12%). Overall, more than half (52%; 247/476) of prescriptions comprised selective serotonin reuptake inhibitors. Slightly less than two-thirds (63%; n = 233) of patients received at least 1 selective serotonin reuptake inhibitor. In addition, 79% of patients were prescribed only 1 antidepressant. The mean number of antidepressants used per patient was 1.25 (standard deviation, 0.56). There were subtle differences in the most preferred antidepressant across medical illnesses such as diabetes mellitus, liver dysfunction, acid peptic disease, and cerebrovascular disease. Differences were also seen in prescription patterns across different countries.

CONCLUSION

Although selective serotonin reuptake inhibitors formed the bulk of antidepressant prescriptions in the presence of medical co-morbidity, mirtazapine was also commonly used in the presence of medical co-morbidities. Specified medical morbidities do influence the selection of antidepressants.

Low efficacy of delthamethrin-treated net against Singapore Aedes aegypti is associated with kdr-type resistance

There has been a worldwide surge in the number and severity of dengue in the past decades. In Singapore, relentless vector control efforts have been put in to control the disease since the 1960's. Space spraying, fogging, chemical treatment and source reduction are some commonly used methodologies for controlling its vectors, particularly Aedes aegypti. Here, as we explored the use of a commercially available delthamethrin-treated net as an alternative strategy and the efficacy of the treated net was found to be limited. Through bioassays and molecular studies, the failure of the treated net to render high mortality rate was found to be associated with the knockdown resistance (kdr) mutation. This is the first report of kdr- mutations in Singapore's Ae. aegypti. At least one point mutation, either homozygous or heterozygous, at amino acid residue V1016G of DIIS6 or F1269C of DIIIS6 was detected in 93% of field strains of Ae. aegypti. Various permutations of wild type and mutant amino acids of the four alleles were found to result in varying degree of survival rate among local field Ae. aegypti when exposed to the deltamethrin treated net. Together with the association of higher survival rate with the presence of both V1016G and F1269C, the data suggest the role of these mutations in the resistance to the deltamethrin. The high prevalence of these mutations were confirmed in a country wide survey where 70% and 72% of the 201 Ae. aegypti analysed possessed the mutations at residues 1016 and 1269 respectively. The highest mutated frequency combination was found to be heterozygous alleles (VG/FC) at both residues 1016 and 1269 (37.8%), followed by homozygous mutation at allele 1269 (24.4%) and homozygous mutation at allele 1016 (22.9%). The kdr- type of resistance among the vector is likely to undermine the effectiveness of pyrethroids treated materials against these mosquitoes.

Pancreatic cystic lesions and guidelines: a review

No abstract available.

CT volumetry of the liver: where does it stand in clinical practice?

Imaging-based volumetry has been increasingly utilised in current clinical practice to obtain accurate measurements of the liver volume. This is particularly useful prior to major hepatic resection and living donor liver transplantation where the size of the remnant liver and liver graft, respectively, affects procedural success and postoperative mortality and morbidity. The use of imaging-based volumetry, with emphasis on computed tomography, will be reviewed. We will explore the various technical factors that contribute to accurate volumetric measurements, and demonstrate how the accuracies of these techniques are influenced by their methodologies. The strengths and limitations of using anatomical imaging to estimate liver volume will be discussed, in relation to laboratory and functional imaging methods of assessment.

Is intravenous contrast necessary for detection of clinically significant extracolonic findings in patients undergoing CT colonography?

OBJECTIVE

To determine whether intravenous contrast (IVC) is necessary for detection of extracolonic findings (ECFs) in patients undergoing CT colonography (CTC).

METHODS

We performed a retrospective review of CT findings in 179 cases of CTC studies performed over 18 months where both pre-contrast (NECT) and post-contrast (CECT) scans were performed in the prone and supine positions, respectively, in the same patients. All ECFs were recorded on a per patient basis and graded according to the colonography reporting and data system classification.

RESULTS

There was no significant change in E grade for the cohort (p = 0.171) between the NECT and CECT scans. On the CECT scans, additional findings were detected in 49.1% of patients. Overall, there were 27/179 (15.1%) patients graded E3 and 18/179 (10.1%) patients graded E4 on the CECT study. Compared with the NECT study, there was a decrease of 12.9% of patients graded E3 and no change in the number of patients graded E4.

CONCLUSION

With IVC administration, additional ECFs are detected in nearly half of all patients. However, there was no increase in the number of patients with clinically significant lesions. The risk-benefit ratio of routine IVC administration for CTC in symptomatic patients thus requires further evaluation.

ADVANCES IN KNOWLEDGE

This study reviews the utility of IVC in CTC and is thus relevant to current clinical practice at many institutions.

IF1 limits the apoptotic-signalling cascade by preventing mitochondrial remodelling

Mitochondrial structure has a central role both in energy conversion and in the regulation of cell death. We have previously shown that IF1 protects cells from necrotic cell death and supports cristae structure by promoting the oligomerisation of the F1Fo-ATPsynthase. As IF1 is upregulated in a large proportion of human cancers, we have here explored its contribution to the progression of apoptosis and report that an increased expression of IF1, relative to the F1Fo-ATPsynthase, protects cells from apoptotic death. We show that IF1 expression serves as a checkpoint for the release of Cytochrome c (Cyt c) and hence the completion of the apoptotic program. We show that the progression of apoptosis engages an amplification pathway mediated by: (i) Cyt c-dependent release of ER Ca(2+), (ii) Ca(2+)-dependent recruitment of the GTPase Dynamin-related protein 1 (Drp1), (iii) Bax insertion into the outer mitochondrial membrane and (iv) further release of Cyt c. This pathway is accelerated by suppression of IF1 and delayed by its overexpression. IF1 overexpression is associated with the preservation of mitochondrial morphology and ultrastructure, consistent with a central role for IF1 as a determinant of the inner membrane architecture and with the role of mitochondrial ultrastructure in the regulation of Cyt c release. These data suggest that IF1 is an antiapoptotic and potentially tumorigenic factor and may be a valuable predictor of responsiveness to chemotherapy.

A novel sodium-dependent uptake system for l-leucine in rat brain synaptosomes

A novel Na(+)-dependent system for the uptake of l-leucine by rat brain synaptosomes is described. At a constant osmolarity of 270 mOsm/L, it functions optimally at a Na(+) concentration of 10 mM. This system is determined by measuring the difference in leucine uptake in the presence and absence of Na(+) as well as by measuring the residual uptake of leucine in the presence of an excess amount of 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid in a Na(+) -containing medium. Mg(2+) is found to enhance leucine uptake in the presence and absence of Na(+). However, its presence in the incubation medium reduces net leucine uptake rates due to Na(+) and also alters K(m) and V(max) values for the Na(+) -dependent uptake system.

Ministry of Health clinical practice guidelines: depression

The Ministry of Health (MOH) have updated the clinical practice guidelines on Depression to provide doctors and patients in Singapore with evidence-based treatment for depression. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Depression, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/home/Publications/guidelines/cpg/2012/depression.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Ministry of Health clinical practice guidelines: schizophrenia

The Ministry of Health (MOH) has updated the clinical practice guidelines on Schizophrenia to provide doctors and patients in Singapore with evidence-based treatment for schizophrenia. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Schizophrenia, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov. sg/mohcorp/publications.aspx?id=26138. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Transradial percutaneous coronary intervention in acute ST elevation myocardial infarction and high-risk patients: experience in a single centre without cardiothoracic surgical backup

INTRODUCTION

Primary transradial percutaneous coronary intervention (TRI) is shown to be efficacious in stable patients with acute coronary syndrome. We aimed to evaluate the application of primary TRI for acute ST elevation myocardial infarction (STEMI), including among high-risk patients from our registry.

METHODS

This was a single-centre case series comprising 138 patients who underwent primary TRI for STEMI between May 2007 and June 2008. TRI was attempted with a 6-Fr guiding catheter in all patients regardless of Killip class status. Outcome measures were success rates of primary TRI, door-to-balloon time, procedure duration and volume of contrast used. All patients were followed up for major adverse cardiac events in-hospital, at 30 days and six months.

RESULTS

A total of 138 patients had primary TRI attempted for STEMI. Four patients failed primary TRI and required a femoral approach. The remaining 134 patients underwent primary TRI. The mean patient age was 56.4 years. Most patients with acute STEMI presented in Killip class I and II (91.8 percent). Only 8.2 percent were in Killip class III or IV on admission. 50 percent of patients presented with anterior STEMI. The median door-to-balloon time for this group was 92 (interquartile range [IQR] 77-121) minutes, with a median procedure time of 39 (IQR 29-51) minutes. The success rate of primary TRI was 97.1 percent.

CONCLUSION

Success rate, procedural and radiation time for TRI are comparable to those achieved via the femoral approach. Primary TRI is therefore a feasible and effective approach for acute STEMI, even in high-risk patients.

Mesenteric desmoid tumour masquerading as a fat-containing cystic mass

Mesenteric desmoid tumour (MDT) is an uncommon neoplasm that typically presents as a solid soft-tissue mass on cross-sectional imaging. MDT manifesting as a fat-containing cystic mass on CT has not been described in the literature. We report such an unusual case with clinicopathological correlation.

ST segment elevation myocardial infarction following elective direct current synchronised cardioversion for atrial fibrillation

Atrial fibrillation is the most common arrhythmia in clinical practice. There is no difference in mortality, incidence of stroke or quality of life regardless of whether the rhythm control or rate control strategy is used. However, in certain circumstances, such as when rate control is inadequate, rhythm control is a viable option. We present a 74-year-old Eurasian man with a history of hypertension who presented with new-onset atrial fibrillation and sustained an ST segment elevation myocardial infarction following elective direct current cardioversion.

A randomised controlled trial of hyperbaric bupivacaine with opioids, injected as either a mixture or sequentially, for spinal anaesthesia for caesarean section

It is common practice to mix opioids with hyperbaric bupivacaine in a single syringe before intrathecal injection of the mixture. Mixing these drugs may alter the density of the hyperbaric solution, affecting the spread of local anaesthetic and opioid. Forty-eight women having elective caesarean section under spinal anaesthesia were recruited to this double-blind, randomised trial. Group M (n=24) received 2 ml of 0.5% hyperbaric bupivacaine plus morphine 100 microg plus fentanyl 15 microg, mixed in a syringe prior to administration. Group S (n=24) received 2 ml of 0.5% bupivacaine through one syringe, followed by morphine 100 microg plus fentanyl 15 microg through a separate syringe. All patients received patient-controlled intravenous morphine for 24 hours postoperatively. Block characteristics, postoperative pain scores and morphine use were noted. The patients in Group M had higher levels of sensory block to cold than those in Group S (median T2 vs. T3) (P = 0.003). Five patients in Group M and none in Group S had a block to cold > or = T1 (P = 0.02). There was no difference between groups in the incidence of hypotension, need for vasopressor or side-effects. Morphine consumption was significantly higher in group M (13.3 +/- 11.2 vs. 6.2 +/- 7.2 mg, P = 0.015). Mixing of fentanyl and morphine with hyperbaric bupivacaine results in a higher level of sensory block than sequential administration of bupivacaine then opioid and may be associated with higher postoperative opioid requirement.

Multidetector row CT diagnosis of an infected right atrial thrombus following repeated dialysis catheter placement

Right atrial thrombus formation is a known complication of dialysis catheter placements. We describe the case of a 61-year-old woman with end-stage renal failure who presented with gram-negative septicaemia. A gas-containing filling defect was noted incidentally in the right atrium during a CT scan of the abdomen and pelvis, indicative of a thrombus infected by a gas-forming organism. The finding correlated with a positive blood culture of Klebsiella pneumoniae and the two-dimensional echocardiography finding of an echogenic atrial thrombus.

Chronic stimulation of corticotropin-releasing factor receptor 1 enhances the anxiogenic response of the cholecystokinin system

Corticotropin-releasing factor (CRF) and cholecystokinin (CCK), two highly colocalized neuropeptides, have been linked to the etiology of stress-related anxiety disorders. Recent evidence points to the possibility that some of the anxiogenic effects of the central CCK system take place through interplay with the CRF system. The aim of the present study was to examine the effects of chronic, mild activation of CRF receptor 1 (CRF(1)) on the central CCK system of the C57BL/6J mouse. As shown by in situ hybridization, real-Time PCR and immunohistochemistry, 5 days of intracerebroventricular (i.c.v.) injections of a subeffective dose (2.3 pmol) of cortagine, a CRF(1)-selective agonist, resulted in an increase in CCK mRNA levels and CCK(2) receptor immunoreactivity in several brain regions, such as amygdala and hippocampus, known to be involved in the regulation of anxiety. Mice with elevated endogenous central CCK tone exhibited significantly higher anxiety-like behaviors in the open-field task and elevated plus maze, and enhanced conditioned fear. These behavioral changes were reversed by i.c.v. administration of the CCK(2)-selective antagonist LY225910, after 5 days of priming with cortagine. Under the same conditions, the intraperitoneal administration of the CRF(1) antagonist antalarmin was ineffective. This result indicated that once the CCK system was sensitized by prior CRF(1) activation, it exhibited its anxiogenic effects, without influence by CRF(1), possibly because of its observed downregulation. In sum, our results provide a novel model for the interaction of the CRF and CCK systems contributing to the development of hypersensitive emotional circuitry.

Knowledge and perceptions regarding colorectal cancer screening among Chinese--a community-based survey in Singapore

OBJECTIVE

Despite the increase in colorectal cancer (CRC) incidence among Chinese in Asia, there are no data on predictors of CRC screening uptake in this population. This study investigated how knowledge and perceptions about CRC correlated with screening behavior in Singaporean-Chinese.

METHODS

A community-based cross-sectional study was carried out on Singaporean-Chinese at least 50 years old in Queenstown Estate, Singapore between 1/1/2006 and 1/2/2006. A questionnaire administered via face-to-face interviews elicited knowledge, perceptions and screening behavior of subjects.

RESULTS

The response rate was 72.4%, with 514 completed responses. Expense was the commonest perceived barrier to screening (56.6% agreed), unlike for other populations. Social influence is important, with 67.5% agreeing to the statement "I would go for CRC screening if my family wanted me to". After excluding confounders, Chinese who had been for fecal occult blood test (FOBT) screening had higher knowledge score (p<0.001), lower perceived severity (p<0.01), were more likely to have been influenced by their family/friends to go for screening (p=0.04) and to have attended screening tests for other diseases (p<0.001).

CONCLUSION

FOBT screening uptake is associated with specific areas of knowledge and perception among Singaporean-Chinese. To increase screening uptake within Chinese populations, clinicians should consider these factors in their approach to patients.

Anti-diabetic effects of Cichorium intybus in streptozotocin-induced diabetic rats

The present study was designed to investigate the hypoglycemic and hypolipidemic properties of an ethanolic extract of Cichorium intybus (CIE) which is widely used in India as a traditional treatment for diabetes mellitus. Male Sprague-Dawley rats aged 9 weeks (160-200 g) were administered with streptozotocin (STZ, 50mg/kg) intraperitoneally to induce experimental diabetes. The Cichorium intybus whole plant was exhaustively extracted with 80% ethanol, concentrated at 40 degrees C using a rotavapor and freeze dried to get powder. Hypoglycemic effects of CIE were observed in an oral glucose tolerance test (OGTT) in which, a dose of 125 mg of plant extract/kg body weight exhibited the most potent hypoglycemic effect. Moreover, daily administration of CIE (125 mg/kg) for 14 days to diabetic rats attenuated serum glucose by 20%, triglycerides by 91% and total cholesterol by 16%. However, there was no change in serum insulin levels, which ruled out the possibility that CIE induces insulin secretion from pancreatic beta-cells. In addition, hepatic glucose-6-phosphatase activity (Glc-6-Pase) was markedly reduced by CIE when compared to the control group. The reduction in the hepatic Glc-6-Pase activity could decrease hepatic glucose production, which in turn results in lower concentration of blood glucose in CIE-treated diabetic rats. In conclusion, our results support the traditional belief that Cichorium intybus could ameliorate diabetic state.

An evidence-based update on nonsteroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs), including both traditional nonselective NSAIDs and the selective cyclooxygenase (COX)-2 inhibitors, are widely used for their anti-inflammatory and analgesic effects. NSAIDs are a necessary choice in pain management because of the integrated role of the COX pathway in the generation of inflammation and in the biochemical recognition of pain. This group of drugs has recently come under scrutiny because of recent focus in the literature on the various adverse effects that can occur when applying NSAIDs. This review will provide an educational update on the current evidence of the efficacy and adverse effects of NSAIDs. It aims to answer the following questions: (1) are there clinically important differences in the efficacy and safety between the different NSAIDs, (2) if there are differences, which are the ones that are more effective and associated with fewer adverse effects, and (3) which are the effective therapeutic approaches that could reduce the adverse effects of NSAIDs. Finally, an algorithm is proposed which delineates a general decision-making tree to select the most appropriate analgesic for an individual patient based on the evidence reviewed.

Biodegradable polymer-silica xerogel composite microspheres for controlled release of gentamicin

Single and double layered composite microspheres were prepared by encapsulating gentamicin-loaded silica xerogels with biodegradable PLGA polymers (poly(DL-lactide-co-glycolide)). The in vitro drug release properties of both the composite microspheres were investigated. The single layered composite microspheres showed a high initial burst, followed by two sustained release stages lasting for approximately 6 weeks. The two sustained release stages of the single layered composite microspheres could be attributed to the swelling and bulk erosion of the polymer encapsulations, respectively. In comparison with the single layered composite microspheres, the double layered composite microspheres realized a much reduced initial burst together with three sustained release stages. The whole release period of the double layered composite microspheres could last more than 9 weeks. These distinct behaviors make the double layered composite microspheres promising as a new drug release material for localized drug delivery applications.

Natural transmission of Plasmodium knowlesi to humans by Anopheles latens in Sarawak, Malaysia

Four species of malaria parasites are known to infect humans. A fifth species, Plasmodium knowlesi, has been reported to infect humans in Malaysian Borneo. Here we report for the first time the incrimination of Anopheles latens as the vector of P. knowlesi among humans and monkeys in Sarawak, Malaysia.

Are they being used safely? A retrospective cross-sectional tertiary health care survey of selective serotonin reuptake inhibitors prescribing practice in Singapore

OBJECTIVES

To determine the prescribing pattern of the SSRIs and to evaluate the safety of current utilization of SSRIs associated with concomitant psychotropic medications in Singapore.

METHODS

The average prescribed daily dose (PDD) for each SSRI was calculated and compared with the defined daily dose (DDD). Pearson's chi2 test, one-way analysis of covariance (ANCOVA) and multinomial logistic regression were performed to examine the impacts of variables such as age, gender, patient type and concomitant psychotropic medications on the utilization of SSRIs. Safety issues were discussed by examining the potential metabolic drug interactions between the SSRIs and concomitant psychotropic medications.

RESULTS

The most frequently prescribed SSRI was fluoxetine and the PDDs were slightly more than the DDDs for all these SSRIs except fluvoxamine. The SSRIs were mainly prescribed to the patients who were younger, female and outpatients. Psychotropics were more likely concomitantly used with fluvoxamine, sertraline and paroxetine, relative to fluoxetine.

CONCLUSION

The prescribing pattern of SSRIs in a tertiary health center in Singapore is generally consistent with the accepted practices, although some safety concerns in terms of metabolic drug interactions were raised. This study provides useful baseline information for further in-depth studies for SSRIs usage both locally and for international comparison.

High dose antipsychotic use in schizophrenia: findings of the REAP (research on east Asia psychotropic prescriptions) study

BACKGROUND

High-dose antipsychotic regimes (defined as the prescription of more than 1000 chlorpromazine-equivalents milligrams of antipsychotic per day) in the management of patients with schizophrenia are not uncommon, but most reports are from western countries. Recent functional neuroimaging studies have found that the previous notion concerning the use of antipsychotic medication, especially in high doses, was unsupported and untenable.

METHODS

This international study examined the use of high dose antipsychotic medication and its clinical correlates in schizophrenia patients within six East Asian countries/territories.

RESULTS

Within the study group (n = 2399), 430 patients (17.9%) were prescribed high dose antipsychotics. Antipsychotic use varied significantly between countries, with Japan, Korea, and Singapore using higher doses than the other countries. High dose antipsychotic use was associated with younger age in Japan (p < 0.001), longer duration of admission (p < 0.001), duration of illness (p < 0.001, particularly in Korea and Taiwan), positive psychotic symptoms (p < 0.001, particularly in Japan and Korea), and aggression (p < 0.05, particularly in Japan), and also with a higher likelihood of extrapyramidal and autonomic adverse effects (p < 0.05, particularly in China). Country, younger age, the presence of delusions and disorganized speech, polypharmacy, and receiving depot medication but not atypical antipsychotic drugs were important predictors of high antipsychotic use.

CONCLUSIONS

This survey revealed that high antipsychotic dosing is not an uncommon practice in East Asia. It behooves the prescribing clinicians to constantly reevaluate the rationale for such a practice.

Self-assembly behavior of a stimuli-responsive water-soluble [60]fullerene-containing polymer

A novel pH- and temperature-responsive water-soluble [60]fullerene-containing poly[2-(dimethylamino)ethyl methacrylate] (C60-b-PDMAEMA) was synthesized by atom transfer radical polymerization. The pH and temperature dependence of the physical properties of the aqueous C60-b-PDMAEMA solution was studied by potentiometric and conductometric titrations, UV-vis transmittance, and laser light scattering techniques. At low pH and at temperatures ranging from 25 to 55 degrees C, in addition to C60-b-PDMAEMA unimers, micelle-like aggregates are produced in the aqueous solution containing C60 hydrophobic cores and protonated PDMAEMA shells. Only unimeric C60-b-PDMAEMAs are found to exist in solution at high pH and low temperature, where PDMAEMA segments form a charge-transfer complex with C60 molecules. However, C60-b-PDMAEMA precipitates from aqueous solution at temperatures exceeding the lower critical solution temperature of PDMAEMA of approximately 45 degrees C. The pH and temperature stimuli-responsive properties of the [60]fullerene-containing polymer in aqueous solution are completely reversible.

A randomized trial of amifostine as a cytoprotectant for patients receiving myeloablative therapy for allogeneic hematopoietic stem cell transplantation

We initiated a randomized study of amifostine (the organic thiophosphate formerly known as WR-2721) given to patients during myeloablative conditioning therapy for allogeneic bone marrow transplantation. Amifostine was given at a dose of 1000 mg/day of conditioning and was well tolerated if attention was given to serum calcium levels, blood pressure and antiemetics. Since August 1998, 60 patients (30 on each arm) have completed the study. There was no significant difference in the days to neutrophil or platelet engraftment in either arm of the study. Significantly, the duration of grade I-IV mucositis was decreased in the group that received amifostine (P=0.02). Also grade III or IV infections (P=0.008), duration of antibiotic therapy (P=0.03) and duration of fever (P=0.04) were significantly reduced with amifostine. However, there were no differences in the incidence of grade III or IV mucositis, liver toxicity or renal toxicity. There were also no differences in early mortality, relapse and long-term survival. We conclude that amifostine, while reducing the duration of mucositis and infections (possibly through some preservation of gut mucosal integrity), has a modest effect in allogeneic bone marrow transplants given the multiplicity of factors influencing organ toxicity and survival in this setting.

Wear behavior of new composite restoratives

This study investigated the wear resistance of recently introduced nanofill (Filtek Supreme [FS], 3M-ESPE) and ormocer (Admira [AM], Voco) composites and compared their wear characteristics to microfill (Filtek A110 [AO], 3M-ESPE]), minifill (Esthet X [EX], Dentsply; Filtek Z250 [ZT], 3M-ESPE) and polyacid-modified (Dyract AP [DY], Dentsply) composites. Six specimens were made for each material. The specimens were conditioned for one week in distilled water at 37 degrees C and subjected to wear testing at 20 MPa contact stress against SS304 counter-bodies using reciprocal compression-sliding wear instrumentation. Distilled water was used as lubricant. Wear depth (microm) was measured using profilometry every 5,000 cycles up to 20,000 cycles. The results were analyzed using ANOVA/Scheffe's test (p<0.05). Wear of the materials was cycle and fatigue dependent. Although no significance in wear was observed between materials after 5,000 cycles of wear testing, significant differences were observed at 10,000 cycles and greater. After 20,000 cycles of wear testing, ranking was as follows: ZT > DY >AM > AO > FS > EX. Wear ranged from 39.90 microm for EX to 113.32 microm for ZT. The wear resistance of ZT and DY was significantly lower than AO, FS and EX In addition, ZT experienced significantly more wear than AM. Under the conditions of this in-vitro study, the wear resistance of nanofill and ormocer composites was comparable or superior to polyacid-modified, microfill and minifill composites.