Ticagrelor was associated with lower fracture risk than clopidogrel in the dual anti-platelet regimen among patients with acute coronary syndrome treated with percutaneous coronary intervention

PURPOSE

Patients with coronary artery disease have increased fracture risks. P2Y12 inhibitors may impact fracture risks. We compared the fracture risks associated with ticagrelor and clopidogrel in dual anti-platelet therapy (DAPT).

METHODS

We identified all adults who underwent first-ever percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) between 2010 and 2017 from a territory-wide PCI registry in Hong Kong. Following 1:1 propensity-score matching for baseline characteristics, patients were followed up till event occurrence, death, or 30 June 2022. Outcomes of interest were major osteoporotic fractures (MOF) identified by validated ICD-9-CM codes. Cox proportional hazards regression was used to compute the hazard ratio (HR) for MOF associated with ticagrelor versus clopidogrel use.

RESULTS

3018 ticagrelor users and 3018 clopidogrel users were identified after propensity-score matching (mean age: 61.4 years; 84.1% men). Upon median follow-up of 6.5 years, 59 ticagrelor users and 119 clopidogrel users sustained MOF (annualized fracture risks: 0.34% and 0.56%, respectively). Ticagrelor use was associated with lower risks of MOF (HR 0.60, 95%CI 0.44-0.83; p = 0.002). Consistent HRs were observed for fractures over vertebrae, hip and upper limbs. Subgroup analyses showed no interaction according to age, sex, presence of diabetes, presence of chronic kidney disease and prior fracture history.

CONCLUSION

Among adults who underwent first-ever PCI for ACS, ticagrelor use in the DAPT was associated with a lower risk of MOF compared with clopidogrel. Our results support the use of ticagrelor in the DAPT from the perspective of bone health.

Fused in sarcoma regulates glutamate signaling and oxidative stress response

Mutations in fused in sarcoma (fust-1) are linked to ALS. However, how these ALS causative mutations alter physiological processes and lead to the onset of ALS remains largely unknown. By obtaining humanized fust-1 ALS mutations via CRISPR-CAS9, we generated a C. elegans ALS model. Homozygous fust-1 ALS mutant and fust-1 deletion animals are viable in C. elegans. This allows us to better characterize the molecular mechanisms of fust-1-dependent responses. We found FUST-1 plays a role in regulating superoxide dismutase, glutamate signaling, and oxidative stress. FUST-1 suppresses SOD-1 and VGLUT/EAT-4 in the nervous system. FUST-1 also regulates synaptic AMPA-type glutamate receptor GLR-1. We found that fust-1 ALS mutations act as loss-of-function in SOD-1 and VGLUT/EAT-4 phenotypes, whereas the fust-1 ALS mutations act as gain-of-function in redox homeostasis and the microbe-induced oxidative stress response. We hypothesized that FUST-1 is a link between glutamate signaling and SOD-1. Our results may provide new insights into the human ALS alleles and their roles in pathological mechanisms that lead to ALS.

Superoxide dismutase SOD-3 regulates redox homeostasis in the intestine

There are four cellular superoxide dismutase paralogs in C. elegans . The role of these superoxide dismutases in redox homeostasis remains largely unknown. Here, we generated the integrated redox reporter rxRFP to detect changes in redox homeostasis using live fluorescence imaging. We found that sod-3 deletion contributes to oxidative stress elevation. Deletions in additional paralogs ameliorate the oxidative stress of sod-3 . Complete elimination of all four paralogs elicits the same increase in rxRFP fluorescence as in the sod-3 single mutation, suggesting a compensatory role of other sod s. Our results suggest that SOD-3 plays a key role in regulating gut redox homeostasis.

The mediating effect of depression on the relationship between osteoarthritis and cardiovascular disease mortality: A cohort study

BACKGROUND

To explore the mediator role of depression in the association of osteoarthritis (OA) and cardiovascular disease (CVD) mortality based on the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

Totally 19,605 adults from NHANES 2009-2018 were included in this cohort study ultimately. The outcome was considered as the CVD related mortality in this study. The follow-up duration was 81.09 ± 1.05 months. Weighted univariate and multivariate linear regressions were used to explore the association between OA and depression. Weighted univariate and multivariate COX regressions were performed to assess the relationship of OA and CVD related mortality. Also, we analyzed the mediating role of depression on the association between OA and CVD mortality through the Sobel Test.

RESULTS

The CVD related mortality in this study was 2.57 %. After adjusting age, gender, physical activity, history of CVD, history of hypertension and eGFR, OA was positively correlated with depression [β = 0.78, 95 % confidence interval (CI) = 0.54-1.02], and OA was associated the death risk of CVD [hazard ratio (HR): 1.35, 95%CI, 1.09-1.68]. Additionally, depression slightly mediated the association between OA and CVD related mortality in this study, with this mediating variable accounting for 5.61 % of the association.

CONCLUSION

OA was associated with depression and CVD related mortality, respectively. Additionally, the increased risk of CVD related mortality in OA patients may be slightly mediated by depression. These results serve as a reminder that giving careful attention to and effectively managing mental health may be beneficial to prevent CVD related mortality, especially for those with OA.

Preclinical evaluation of the VEGF/Ang2 bispecific nanobody BI 836880 in nasopharyngeal carcinoma models

Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) is endemic to parts of Asia and overexpression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α are common in NPC. Anti-vascular agents have known clinical activity in patients with recurrent/ metastatic NPC and in this study, we investigated the anti-tumor effect of BI 836880, a humanized bispecific nanobody against VEGF and angiopoietin-2 (Ang2), in preclinical models of EBV-positive and EBV-negative NPC. The efficacy of BI 836880 was also compared with bevacizumab, a recombinant humanized monoclonal antibody against VEGF. We found that BI 836880 could exert growth-inhibitory effect on endothelial cells (HUVEC-C) and the EBV-negative NPC cell line (HK1), but to a lesser extent in the EBV-positive NPC cell lines, C17C and C666-1. In patients-derived xenograft (PDX) models of NPC - Xeno-2117 and Xeno-666, BI 836880 could suppress tumor growth and Ki67, as well as induce tumor necrosis and reduce microvessel density. Moreover, treatment with BI 836880 increased the level of macrophage infiltration in both PDX tumor models of NPC, suggesting that BI 836880 may exert immunomodulatory effect on the NPC immune microenvironment. When compared with bevacizumab, BI 836880 appeared to show at least comparable activity as bevacizumab in terms of its anti-proliferative and anti-angiogenic effects. This study showed that BI 836880 has anti-proliferative, anti-angiogenic and possibly immunomodulatory effect in clinical models of NPC, therefore the dual targeting of VEGF and Ang2 signaling in NPC should be further investigated.

Neutrophil-Lymphocyte Ratio as a Predictor of Cerebral Small Vessel Disease in a Geriatric Community: The I-Lan Longitudinal Aging Study

Cerebral Small Vessel Disease (CSVD) frequently affects the elderly, with inflammation playing a crucial role in related health complications, including dementia, stroke, and SVD. Studies, including animal experiments, indicate a strong link between inflammation and SVD progression. The Neutrophil-Lymphocyte Ratio (NLR) serves as a possible biomarker for ongoing inflammatory risks. A total of 720 adults aged 50 years or older from the community-based I-Lan Longitudinal Aging Study were included in this study. General linear regression and ordinally logistic regression analyses were performed to evaluate the association between NLR and CSVD. We further examined the presence of lacune, microbleed, and white matter hyperintensity (WMH) on brain MRI, which were used to construct a combined CSVD score. The NLR was positively associated with WMH (adjusted r = 0.109, p = 0.003), microbleed (adjusted r = 0.102, p = 0.006), and lacune (adjusted r = 0.100, p = 0.008). After adjustments for smoking, drinking, and physical activity in the ordinal logistic regression analysis, age, gender, brachial Systolic Blood Pressure (SBP), fasting glucose, LDL-cholesterol, and Hs-CRP were compared among subjects with low tertile (T1), medium tertile (T2) and high tertile (T3) NLR. The results showed that T2 vs. T1 had an odds ratio of 1.23 (0.86-1.77); and T3 vs. T1 had an odds ratio of 1.87 (1.29-2.71) of CSVD scores in four groups (zero (reference group), one, two, and three or more). NLR could be used to assess the state of inflammation in cerebral vessels. A significant and positive correlation between NLR and CSVD was verified in this study. However, the practical clinical application of NLR in CSVD patients and prognosis prediction should be validated through more scientific attempts.

Thermal Disorder in Finite-Length Carbon Nanowire

Enhancement in chemisorption is one of the active research areas in carbon materials. To remedy the thermally degraded chemisorption occurring at high temperatures, we report a comprehensive study of kink structures in free-standing monoatomic carbon nanowires upon heating. Our Monte Carlo simulation considers multi-monoatomic carbon chains laterally interacting by van der Waals forces. Our study reveals that carbon nanowires maintain their linearity regardless of chain length at low temperatures, but this is not the case at high temperatures. Disordered kink structure is observed in short carbon chains, especially above the Peierls transition temperature. A severe kink structure may increase the possibility of attaching negatively charged atoms, thereby contributing to the development of next-generation materials for chemisorption at high temperatures. We have also provided an important indication that any physical property of the finite-length carbon chain predicted by ab initio calculation should reconsider the atomic rearrangement due to thermal instability at high temperatures.

Report of a Patient With Anti-Jo-1 Syndrome With Loss of Consciousness

A 51-year-old febrile woman presented to the emergency department because of loss of consciousness while worshipping at a temple. She experienced muscle weakness and blurred vision before fainting. She also felt pain in her left shoulder and suffered from dry cough and shortness of breath during the previous week. The chest radiograph (CXR) showed bilateral reticular infiltration, indicating interstitial lung disease (ILD), and chest computed tomography revealed reticular, nodular, and reticulonodular patterns of infiltration that were compatible with ILD. Blood tests showed a creatinine kinase level of 3,307 IU/L and an Anti-Jo-1 autoantibody level of 586 AU/mL. It was found via right thigh biopsy results 8 days later that she had polymyositis with perivascular inflammation and degenerative muscle fiber change. Pulse therapy with methylprednisolone (1 gm/day for 3 days) was administered. After 4 days, she felt better and was discharged. Around 25.0%-34.1% of myositis patients have anti-Jo-1 autoantibodies, and ILD was noted in 65%-68% of anti-Jo-1-positive patients. A ground glass pattern may be observed in the CXRs of anti-Jo-1 ILD patients, and some articles described multiple pulmonary nodules mimicking lung metastasis or concomitant with pleural effusion. The conditions of approximately 42%-66% of ILD patients are controlled or are not worsened after treatment with corticosteroid and immunosuppressive drug treatment. However, some rapidly progressive cases are not sensitive to corticosteroid therapy alone.

Creation of Si quantum dots in a silica matrix due to conversion of radiation defects under pulsed ion-beam exposure

In this work we present an innovative method of creating Si quantum dots under pulsed ion-beam exposure. The evolution of defect structure ODC(II) → E'→ ODC(I) → Si QDs in glassy SiO₂ under ion-beam implantation was established by optical absorption and photoluminescence spectroscopies. Depending on the mode of ion exposure, it is possible to easily control the type and concentration of defects in the host and modify its optical properties for novel applications. Ab initio calculations confirm that bond softening in SiO₂ is attainable via the use of Gd ion implantation. According to our experimental and theoretical results, the three-stage interaction of primary oxygen-deficient centers leads to the formation of stable silicon quantum dots with a size of 3.6 nm and luminescence at 1.8 eV excited by incoherent light.

Impact of whole egg intake on blood pressure, lipids and lipoproteins in middle-aged and older population: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Effects of whole egg consumption on cardiovascular diseases (CVD) risk in the middle-aged and older population remain unclear due to inconsistent findings from observational and randomized controlled trials (RCTs). This meta-analysis aimed to assess the impacts of whole egg and egg category (whole eggs versus egg substitutes) intake quantity on CVD risk factors from systematically searched RCTs. Egg substitutes were hypothesized to have minimal effects of the blood lipid and lipoprotein profile as they are void of dietary cholesterol.

METHODS AND RESULTS

As many as 434 studies identified from PubMed, Cochrane Library, CINAHL and Medline (Ovid) databases were screened and data were extracted from 8 selected RCTs. Quality of the selected studies were assessed and the overall effect sizes of weighted mean differences (WMD) were calculated using a random effects model. Non-differential effects in blood pressures, lipids and lipoproteins were observed when >4 whole eggs/week compared to ≤4 whole eggs/week were consumed. Intake of >4 whole eggs/week compared to equivalent amounts of egg substitutes caused greater elevations in blood total cholesterol (WMD: 0.198 mmol/L; 95% CIs: 0.056, 0.339), HDL cholesterol (WMD: 0.068 mmol/L; 95% CIs: 0.006, 0.130) and LDL cholesterol (WMD: 0.171 mmol/L; 95% CIs: 0.028, 0.315) but did not differentially affect triglycerides concentration.

CONCLUSION

Overall, the results support the notion that quantity of whole egg intake does not affect CVD risk factors and consuming egg substitutes may also be beneficial compared to whole eggs on lowering CVD risk in the middle-aged and older population.

Room temperature p-orbital magnetism in carbon chains and the role of group IV, V, VI, and VII dopants

The study of magnetism without the involvement of transition metals or rare earth ions is considered the key to the fabrication of next generation spintronic devices. Several recent reports claim that optimizing the occupation number of the mixed p-orbitals is the correct way to reinforce p-orbital magnetism in bulk crystals. We provide experimental evidence that the kinked monoatomic carbon chains, the so-called linear-chained carbon, generate intrinsic ferromagnetism even above room temperature. According to our ab initio calculations, unconventional magnetism has its origin in the p-shells. In contrast, the linear monoatomic carbon chains are non-magnetic. Although the optimized differential spin density of states at the Fermi level (SDOS) of the kinked carbon chains is higher than that of bulk Fe, the magnetic moment is as low as 0.3μB. In order to enhance the magnetic response, we decided to tune the p-orbital magnetism by adding dopants from groups IV to VII of the periodic table. We observed that the strength of the p-orbital magnetism and the sign of the exchange interaction depend not only on the kink angle, but also on the concentration of lone pair electrons, free radical electrons, lateral chain spacing, internal electric dipole, dative covalent bonds and the Bohr radius of the dopants. Surprisingly, the V and VII-doped carbon chains show a strong non-zero SDOS, which has its origin in the p-shells. The VII-doped carbon chains give the SDOS of the opposite sign. Our best system, the arsenic-doped carbon chain, exhibits a strong local magnetic moment of 1.5μB, which is comparable to that of the bulk Fe of 2.2μB, with the mean exchange-correlation energy reaching a 63% ratio relative to that of the bulk Fe.

A theoretical quest for high temperature superconductivity on the example of low-dimensional carbon structures

High temperature superconductivity does not necessarily require correlated electron systems with complex competing or coexisting orders. Instead, it may be achieved in a phonon-mediated classical superconductor having a high Debye temperature and large electronic density of states at the Fermi level in a material with light atoms and strong covalent bonds. Quasi-1D conductors seem promising due to the Van Hove singularities in their electronic density of states. In this sense, quasi-1D carbon structures are good candidates. In thin carbon nanotubes, superconductivity at ~15 K has been reported, and it is likely the strong curvature of the graphene sheet which enhances the electron-phonon coupling. We use an ab-initio approach to optimize superconducting quasi-1D carbon structures. We start by calculating a T_c of 13.9 K for (4.2) carbon nanotubes (CNT) that agrees well with experiments. Then we reduce the CNT to a ring, open the ring to form chains, optimize bond length and kink structure, and finally form a new type of carbon ring that reaches a T_c value of 115 K.

Views of faculty members in a medical school with regards to error disclosure and reporting to parents and/or higher authorities

BACKGROUND

Little is known about the views of faculty members who train medical students concerning open disclosure.

OBJECTIVES

The objectives of this study were to determine the views of faculty in a medical school on: 1 what constitutes a medical error and the severity of such an error in relation to medication use or diagnosis; 2 information giving following such an adverse event, based on severity; and 3 acknowledgement of responsibility, remedial action, compensation, disciplinary action, legal action, and reporting to a higher body in relation to such adverse event.

METHODS

We adapted and contextualized a questionnaire developed from a previous study. The questionnaire had 4 case vignettes that described 1 clear medication error with lifelong disability; 2 possible diagnostic error with lifelong disability; 3 possible diagnostic error without harm; and 4 clear medication error without harm. We invited all faculty members attached to the medical school at the International Medical University to participate in the study.

RESULTS

Seventy faculty members took part. Faculty members viewed a medical error as having taken place depending on how clearly an error had occurred (94% and 73% versus 53% and 27%). They viewed cases as more severe based on the severity of complications (85% and 46% versus 5% and 10%). With increasing severity, they tended to attribute responsibility for the event and the duty to disclose towards more senior clinicians. They were also more agreeable with remedial action, compensation, disciplinary action, and reporting to a higher agency. There was no strong evidence of association between these areas and the demographics of faculty members.

CONCLUSIONS

Faculty members are more likely to perceive an error had occurred depending on the clarity of the circumstances. They viewed severity based on the presence of complications. Severity determined how they attributed responsibility, duty to disclose, and other areas related to open disclosure.

Parental preferences with regards to disclosure following adverse events occurring in relation to medication use or diagnosis in the care of their children - perspectives from Malaysia

INTRODUCTION

Open disclosure is poorly understood in Malaysia but is an ethical and professional responsibility. The objectives of this study were to determine: (1) the perception of parents regarding the severity of medical error in relation to medication use or diagnosis; (2) the preference of parents for information following the medical error and its relation to severity; and (3) the preference of parents with regards to disciplinary action, reporting, and legal action.

METHODS

We translated and contextualised a questionnaire developed from a previous study. The questionnaire consisted of four case vignettes that described the following: medication error with a lifelong complication; diagnostic error with a lifelong complication; diagnostic error without lifelong effect; and medication error without lifelong effect. Each case vignette was followed by a series of questions examining the subject's perception on the above areas. We also determined the content validity of the questionnaire. We invited parents of Malaysian children admitted to the paediatric wards of Tuanku Jaafar Hospital to participate in the study.

RESULTS

One hundred and twenty-three parents participated in the study. The majority of parents wanted to be told regarding the event. As the severity of the case vignettes increased, the desire for information, remedial action, acknowledgement of responsibility, compensation, punishment, legal action, and reporting to a higher agency also increased. The findings did not have strong evidence of a relationship with subject's demographics.

CONCLUSION

This study gives insights into previously unexplored perspectives and preferences of parents in Malaysia regarding open disclosure. It also highlights the opportunity for more research in this area with potentially broad applications.

Epilepsy in patients with primary brain tumors: The impact on mood, cognition, and HRQOL

BACKGROUND

A primary brain tumor (PBT) is often a fatal disease of the nervous system and has a serious impact on health-related quality of life (HRQOL). Presence of epilepsy and adverse reactions from tumor and epilepsy treatments may cause additional decline in HRQOL.

OBJECTIVES

We aimed to study the impact of epileptic seizures on cognition, mood, and HRQOL in patients with brain tumor-related epilepsy.

MATERIALS AND METHOD

Patients were grouped on an ordinal scale according to epilepsy burden from none to severe based on the presence of epileptic seizures and seizure frequency: L1, no epilepsy; L2, with epilepsy, seizure-free in the last 6 months with antiepileptic drugs; and L3, with epilepsy, at least one seizure in the last 6 months with AEDs. Health-related quality of life was measured by Functional Assessment of Cancer Therapy-Brain (FACT-Br) and Quality of Life in Epilepsy-31 (QOLIE-31) tools, cognition by the Montreal Cognitive Assessment (MoCA) tool and Frontal Assessment Battery (FAB), mood by the Hospital Anxiety and Depression Scale (HADS), activities of daily living (ADLs) by the Barthel Index (BI), and performance status by the Karnofsky Performance Status (KPS) scale in patients with primary brain tumors at least one month following neurosurgery with or without radiotherapy and chemotherapy.

RESULTS

Eighty-one patients with a diagnosis of primary brain tumors were recruited. Sixty-eight percent of patients were diagnosed with primary brain tumor-related epilepsy, 50.61% patients had cognitive impairment, 33% had abnormal scores in the anxiety scale, and 34% had abnormal scores in the depression scale. There were no statistically significant differences in these scores among L1, L2, and L3 groups. There were statistically significant differences in duration of disease and KPS and BI scores between L1 and L3 groups. The L3 group has significantly longer duration of disease and scored low in both the BI and KPS scale when compared to the L1 group. All patients with primary brain tumors scored significantly low in FACT-Br 'physical well-being' (PWB) and 'emotional well-being' (EWB) and high in 'social well-being' (SWB) when compared to healthy controls. When scores of each group were individually compared to healthy controls, the L3 group showed the lowest scores in PWB, EWB, and 'functional well-being'. In SWB, L1 and L2 groups showed statistically significantly high scores when compared to normative data. The QOLIE-31 applied to groups with epilepsy showed statistically significantly lower scores in the L3 group when compared to the L2 group in 'cognitive' and 'social functioning' domains. On multivariate analysis, both poor performance status and frequency of seizures were found to be independent risk factors for poor HRQOL when FACT-Br mean scores were compared. Level of seizures was found to be an independent risk factor for poor HRQOL when QOLIE-31 scores were compared between L2 and L3 groups.

DISCUSSION

Presence of brain tumors could be attributed to cognitive impairment irrespective of the presence of epilepsy in our cohort. High seizure burden is an independent risk factor for poor HRQOL in patients with primary brain tumors. The QOLIE-31 is a more sensitive tool than the FACT-Br because of the presence of a seizure-related questionnaire.

Early diagnosis of necrotizing fasciitis

BACKGROUND

Necrotizing fasciitis is a rapidly progressing skin infection characterized by necrosis of the fascia and subcutaneous tissue, accompanied by severe systemic toxicity. The objective of this systematic review was to identify clinical features and investigations that will aid early diagnosis.

METHODS

A systematic literature search of PubMed was undertaken using the keywords 'necrotising fasciitis', 'necrotising skin infection', 'diagnosis' and 'outcome'. Case series of 50 or more subjects with information on symptoms and signs at initial presentation, investigations and clinical outcome were included.

RESULTS

Nine case series were selected, with a total of 1463 patients. Diabetes mellitus was a co-morbidity in 44.5 per cent of patients. Contact with marine life or ingestion of seafood in patients with liver disease were risk factors in some parts of Asia. The top three early presenting clinical features were: swelling (80.8 per cent), pain (79.0 per cent) and erythema (70.7 per cent). These being non-specific features, initial misdiagnosis was common and occurred in almost three-quarters of patients. Clinical features that helped early diagnosis were: pain out of proportion to the physical findings; failure to improve despite broad-spectrum antibiotics; presence of bullae in the skin; and gas in the soft tissue on plain X-ray (although this occurred in only 24.8 per cent of patients).

CONCLUSION

A high index of suspicion of necrotizing fasciitis is needed in a patient presenting with cutaneous infection causing swelling, pain and erythema, with co-morbidity of diabetes or liver disease. The presence of bullae, or gas on plain X-ray can be diagnostic. Early surgical exploration is the best approach in the uncertain case.

Topological transport in spin-orbit coupled bosonic Mott insulators

We investigate topological transport in spin-orbit coupled bosonic Mott insulators. We show that interactions can lead to anomalous quasiparticle dynamics even when the spin-orbit coupling is Abelian. To illustrate the latter, we consider the spin-orbit coupling realized in the experiment of Lin et al. [Nature (London) 471, 83 (2011)]. For this spin-orbit coupling, we compute the quasiparticle dispersions and spectral weights, the interaction-induced momentum-space Berry curvature, and the momentum-space distribution of spin density, and propose experimental signatures. Furthermore, we find that, for a generic spin orbit coupling, in our approximation for the single-particle propagator, the ground state can in principle support an integer Hall conductivity if the sum of the Chern numbers of the hole bands is nonzero.

Spin caloritronics in noncondensed Bose gases

We consider coupled spin and heat transport in a two-component atomic Bose gas in the noncondensed state. We find that the transport coefficients show a temperature dependence reflecting the bosonic enhancement of scattering and discuss experimental signatures of the spin-heat coupling in spin accumulation, spin separation, and total dissipation. Close to the critical temperature for Bose-Einstein condensation, we find that the spin-heat coupling is strongly reduced, which is also reflected in the spin caloritronics figure of merit that determines the thermodynamic efficiency of spin-heat conversion.

SUICIDAL MERCURY INJECTION INTO THE UPPER LIMB: A CASE STUDY

We report a rare case of self-injection of mercury into the subcutaneous tissue of the upper limb. A multi-disciplinary management approach was adopted including cooperation between toxicologists, orthopaedic surgeons, radiologists and environment safety personnel. Surgical removal of mercury under radiological screening and systemic intoxication treated by chelating agents, namely dimercaprol and succimer. Serial serum and urine mercury levels showed an initial rise despite surgical removal and returned to normal after a prolonged period of time. Safety precautions were taken during surgery to avoid inadvertent intoxication of staff. Contamination of the operation theatre was monitored by the amount of mercury vapour released into the air. All personnels involved in the management of the patient did not show any evidence of mercury intoxication.

ULTRASOUND FOR THE DETECTION OF VEGETATIVE FOREIGN BODY IN HAND — A CASE REPORT

Foreign bodies in soft tissues are commonly encountered in daily orthopaedic practice. While most of the metals and glass foreign bodies can be detected by plain radiograph, organic substances such as wood and vegetative materials are radiolucent. Unfortunately, these radiolucent foreign bodies are usually more prone to cause an inflammatory reaction and infection. The detection can be even more difficult in cases of multiple foreign bodies and in penetrating injuries with small innocuous skin wounds. Ultrasonography is a sensitive and reliable investigation for detection of foreign bodies in soft tissue. We present a case of penetration injury to thumb with residual radiolucent foreign bodies and demonstrate the proper role of ultrasonography in the management of foreign bodies in soft tissues.

Piriformis pyomyositis: a report of three cases

Pyomyositis is a subacute infection of skeletal muscles. It can be life-threatening if diagnosis and treatment are delayed. Only 5 cases of isolated piriformis pyomyositis have been reported. We report signs and symptoms of piriformis pyomyositis in 3 women who were treated mainly with antibiotics. Computed tomography is useful in making the diagnosis. Early diagnosis and treatment may avoid surgical treatment and reduce mortality.

Tumour seeding following percutaneous needle biopsy of hepatocellular carcinoma

We report a hepatocellular carcinoma seeding following needle biopsy in a 57-year-old man who first presented with a focal hepatic lesion at another hospital. The patient had been a hepatitis B carrier for 20 years. Initial surveillance ultrasonography showed a lesion in segment IV, in the background of non-cirrhotic liver and normal serum alpha-foetoprotein level (8 ng/ml). A percutaneous needle biopsy was done and histopathology confirmed well-differentiated hepatocellular carcinoma. The patient had refused surgery and preferred to try traditional medicine. He presented to us four months after the initial biopsy with epigastric swelling. This was found to be due to a tumour seeding along the previous biopsy tract. He was given radiofrequency ablation (RFA) of tumour along the needle tract, in addition to the primary tumour. We conclude that the need for percutaneous needle biopsy should be critically evaluated in patients presenting with focal hepatic lesions and the role of RFA in treating tumour seeding needs further evaluation.

Gastro-oesophageal reflux disease in chronic laryngitis: prevalence and response to acid-suppressive therapy

BACKGROUND

Gastro-oesophageal reflux is thought to cause chronic laryngitis through laryngopharyngeal reflux. Response of laryngitis to treatment with acid-suppressive therapy supports this causal link.

AIM

To determine the prevalence of gastro-oesophageal reflux disease in patients with chronic laryngitis and response to proton-pump inhibitor therapy.

METHODS

Patients with chronic laryngitis were recruited. The frequency and severity of reflux and laryngeal symptoms were scored and laryngitis graded by laryngoscopy. All patients underwent esophagogastroduodenoscopy and 24-h ambulatory pH monitoring before receiving lansoprazole 30 mg b.d. for 8 weeks.

RESULTS

The prevalence of gastro-oesophageal reflux disease was 65.6% (21 of 32). Based on positive pH test, the prevalence was 25% (eight of 32). The change in laryngeal symptom score and laryngitis grade was significantly higher in GERD compared with non-GERD patients (P = 0.010 for both). The proportion of patients with marked/moderate improvement in laryngeal symptoms were significantly higher in patients with reflux (14 of 21, 67%) compared to those without reflux (two of 11, 18%; P = 0.026).

CONCLUSIONS

The prevalence of gastro-oesophageal reflux disease amongst our patients with chronic laryngitis was high. The response to treatment with proton-pump inhibitors in patients with reflux disease compared to those without underlined the critical role of acid reflux in a subset of patients with chronic laryngitis.

Outcome of pregnancy in patients with systemic lupus erythematosus

OBJECTIVE

To study the maternal and fetal outcomes in women with systemic lupus erythematosus (SLE).

MATERIALS AND METHODS

Over a period of 10 years, 24 pregnancies in 17 females with SLE in a single center were enrolled. Fetal and maternal outcomes were studied retrospectively.

RESULTS

The mean patient age was 27.7 years. Twenty-one of the 24 pregnancies occurred in the period of disease remission at the time of conception. Proteinuria presented in 12 pregnancies; however, no patient developed acute renal failure or deterioration of renal function. There were three cases of preeclampsia in this study. Two patients had their disease flare up and delivered stillborns. One woman with secondary antiphospholipid syndrome (APS) had a fetal loss. There was no maternal mortality. The mean gestation age was 34.3 weeks (range, 17-41 weeks), and the mean birth weight was 2,179 g. The mean APGAR scores were 8 and 9 at 1 and 5 minutes, respectively. One baby with congenital atrioventricular block was born to a mother with positive anti-SSA antibody. There were five cases (20.8%) of intrauterine growth retardation and 10 preterm deliveries (41.6%) in this study.

CONCLUSION

Pregnancy is relatively safe in women with SLE in remission but should be considered as a high-risk pregnancy. APS is associated with poor pregnancy outcome. The patient needs to cooperate with obstetricians and physicians for optimal disease control and detailed monitoring throughout the gestation.

Gastro-oesophageal reflux disease in 'difficult-to-control' asthma: prevalence and response to treatment with acid suppressive therapy

BACKGROUND

The causal association between gastro-oesophageal reflux disease (GERD) and difficult-to-control asthma is unclear.

AIM

To determine the prevalence of GERD and response to proton pump inhibitor therapy in patients with difficult-to-control asthma.

METHODS

Consecutive patients with difficult-to-control asthma as defined by persistent and recurrent symptoms despite on optimal asthmatic medications were recruited for the study. GERD was diagnosed by symptoms, gastroscopy and 24-h oesophageal pH monitoring. All patients were prescribed a course of lansoprazole 30 mg daily for 8 weeks. Improvement to treatment was assessed by a change in pulmonary symptom score and also by patient's subjective assessment of improvement.

RESULTS

Seventeen of 30 (56.7%) patients with difficult-to-control asthma were diagnosed with GERD. Pulmonary symptom score improved significantly only in patients with GERD (35.0 to 21.0; P = 0.002). Twelve of 16 (75%) patients with GERD reported an improvement in asthma symptoms; 1 of 11 (9.1%) without GERD reported mild symptom improvement. There was no significant change in peak expiratory flow rate and forced expiratory volume.

CONCLUSIONS

More than half of patients with difficult-to-control asthma were diagnosed with GERD. In these patients the severity of asthma improved significantly with potent acid suppression therapy. This underlines the critical role of acid reflux in this subset of patients with difficult-to-control asthma.

Treatment of long, diffuse in-stent restenosis with sirolimus-eluting stents

Treatment of long, diffuse in-stent restenosis remains a therapeutic challenge. We report the successful use of multiple sirolimus-eluting stents (three 33-mm long stents) in a long, diffuse in-stent restenotic lesion. No major adverse cardiovascular events, including acute/subacute/delayed stent thrombosis, were noted at ten months. Angiography at six months showed widely patent stents with 19% restenosis only at the worst segment.

The use of a distal occlusion balloon protection device in acute coronary syndrome

We report our early experience in using the PercuSurge GuardWire Plus system as a distal protection device in patients with acute coronary syndrome and acute myocardial infarction. Forty-three patients received percutaneous coronary intervention with the GuardWire Plus system. Thirteen had unstable angina, five had non-Q myocardial infarction and 25 had ST segment elevation myocardial infarction. Forty-one target lesions were in native coronary vessels and two were in saphenous vein grafts. Total occlusion occurred in 18 patients. The mean occlusion time by the distal protective balloon was 262.8 +/- 114.1 s. Preoperatively, TIMI 0 flow was present in 18, TIMI II flow in two and TIMI III flow in 23 patients. Post-operatively, TIMI II and TIMI III flow were established in two and 41 patients, respectively. All procedures were successful and the GuardWire Plus system was successfully deployed in all but two patients. There was no procedure-related major adverse clinical event. There was no major adverse clinical event at 30 days. There was no device-related complication. We believe that the GuardWire Plus system is safe and feasible in patients with acute coronary syndrome and acute myocardial infarction.

Correlates of habitual walking and sports/leisure-time physical activity in older persons in Singapore: interaction effects between educational attainment and gender

INTRODUCTION

We examined for demographic and psychosocial correlates on the participation of habitual walking and sports/leisure-time physical activity (LTPA) among older persons in Singapore.

MATERIALS AND METHODS

In an observational study, 177 Chinese, community/urban-dwelling, ambulant, non-disabled participants > or = 50 years old were recruited from a health promotion programme. The main outcome measures were self-reported participation in habitual walking and sports/LTPA. Variables examined include highest educational attainment, demographic and health characteristics, social contact and health knowledge. Interaction between gender and educational attainment was also examined.

RESULTS

The mean age of participants was 62.5 +/- 7.8 years. The effects of educational level were significant on habitual walking (P = 0.02), while that of age, self-rated health and interaction between gender and educational level were significant for sports/LTPA (P = 0.012, P = 0.002 and P = 0.019, respectively). Men with higher education had a higher self-reported sport/LTPA, while in women; those with lower education attainment had a higher participation.

CONCLUSION

Unlike findings from Western developed nations, previous studies done in Japan and Singapore found that educational level and health behaviours may not be positively associated. In this study, there is a negative correlation between educational attainment and participation in habitual walking and sports/LTPA, especially among older Singaporean women.

Subcutaneous injection of metallic mercury

Deliberate self-injection of metallic mercury into subcutaneous tissue is uncommon. A 41-year-old lady with a history of schizophrenia was admitted to our hospital after deliberate injection of metallic mercury into her right wrist and antecubital fossa. Physical examination was unremarkable except for the injection marks over right antecubital fossa and wrist. The presence of subcutaneous mercury deposits in her right elbow and wrist was confirmed by X-rays and ultrasound scan. Three days later, erythema, swelling, induration and tenderness were seen over the injection sites. At the operation on day 9, mercury streaks were seen within the brachialis muscle belly, surrounded by friable necrotic tissues along the tract. A similar picture was noted in her right wrist. The necrotic tissues and mercury streaks were removed. The patient had been unco-operative and she only received incomplete treatment with dimercaprol and 2,3-dimercaptosuccinic acid. Her total blood mercury level (normal < 50 nmol/L) decreased from 101-151 nmol/L in the first two weeks to 42 nmol/L 3 months later. Her 24-hour urinary mercury excretion (normal < 10 nmol) changed from 55.7-209.5 nmol in the first 7 weeks to 125.4 nmol 3 months later. This case illustrates that soft tissue metallic mercury can produce local necrosis and may allow continuous absorption with persistent elevations in blood and urinary mercury levels. Therefore, early surgical removal of subcutaneous mercury deposits is required to prevent local complications and minimize the risk of systemic absorption and toxicity.

Renal angioplasty under protection of the PercuSurge GuardWire Plus System

Renal artery revascularization with angioplasty may preserve renal function and facilitate hypertension control. However, in a significant proportion of patients, renal function may deteriorate after the procedure. Distal microembolization has been implicated as a possible cause; it may be prevented with distal protection during the procedure. We report a case of successful renal angioplasty and stenting using the PercuSurge GuardWire Plus system.

Failure of retrograde cerebral perfusion to attenuate metabolic changes associated with hypothermic circulatory arrest

OBJECTIVES

Although retrograde cerebral perfusion has become a popular adjunctive technique and may improve cerebral ischemic tolerance during hypothermic circulatory arrest, direct cerebral metabolic benefit has yet to be demonstrated in human subjects. We investigated the post-arrest metabolic phenomena with and without retrograde cerebral perfusion in patients.

METHODS

In a prospective randomized trial, 42 patients undergoing aortic surgery requiring hypothermic circulatory arrest were allocated to receive hypothermic circulatory arrest alone (n = 21) or hypothermic circulatory arrest with additional retrograde cerebral perfusion (n = 21). Circulatory arrest was commenced at 15 degrees C, and retrograde perfusion was instituted through the superior vena cava at a maximum jugular bulb pressure of 25 mm Hg. Transcranial, paired, repeated samples of the arterial and jugular bulb blood were analyzed for oxygen and glucose. Velocity in the right middle cerebral artery was also measured simultaneously.

RESULTS

There were 3 (7.1%) deaths and 3 (7.1%) episodes of neurologic deficit. Mean bypass and circulatory arrest duration (in minutes) were similar between groups (P =.4 and.14). The mean retrograde perfusion duration was 23 minutes. Post-arrest nasopharyngeal temperature was similar (15.3 degrees C vs. 15.3 degrees C). Retrograde perfusion did not affect post-arrest oxygen extraction, glucose extraction, or jugular bulb Po(2). There was no immediate lactate release immediately after hypothermic circulatory arrest.

CONCLUSIONS

Retrograde cerebral perfusion did not influence immediate post-arrest nasopharyngeal temperature or cerebral metabolic recovery. The low jugular bulb Po(2) suggests equivalent ischemia. These findings cast doubt on the effectiveness of retrograde cerebral perfusion as a metabolic adjunct to hypothermic circulatory arrest.

Dansyl-PQRamide, a possible neuropeptide FF receptor antagonist, induces conditioned place preference

Neuropeptide FF (NPFF) is an endogenous anti-opioid peptide. NPFF could potentiate the naloxone-precipitated morphine withdrawal syndromes in morphine-dependent rats, indicating the possible involvement of the endogenous NPFF system in opioid analgesia and dependence. The present study was performed to examine the effects of dansyl-PQRamide (dns-PQRa), a putative NPFF antagonist, on conditioned place preference (CPP), in addition, its interaction with the opioid system. Two CPP experiments were conducted. First, rats were treated with dns-PQRa (4-13 mg/kg, i.p.) and paired with the non-preferred compartment while the vehicle was paired with the preferred compartment. Second, similar to experiment 1 except naloxone (1 mg/kg, i.p.) was given 10 min prior to each dns-PQRa administration. The post-drug place preference was examined after 4 alternative pairings. Another group of animals after repetitive dns-PQRa treatments were analyzed for levels of neurotransmitters in discrete brain areas. Dns-PQRa (4-13 mg/kg, i.p.) induced a significant dose-dependent CPP. The dns-PQRa-induced CPP was completely blocked by pretreatment with 1 mg/kg i.p. naloxone, while naloxone alone did not induce any place aversion. The chronic dns-PQRa-treated (13 mg/kg, i.p., b.i.d.) rats caused a significant increase in 3,4-dihydroxyphenylacetic acid and 5-hydroxyindoleacetic acid in the olfactory tubercle compared to the vehicle-treated controls. There was also an increase in the turnover of serotonin in the olfactory tubercle, nucleus accumbens and medial prefrontal cortex. These results suggest that blockade of the NPFF system produces rewarding, possibly via an inhibition of the anti-opioid action of NPFF. These results also reveal a close relationship between NPFF, drug rewarding and the dopaminergic and serotoninergic neurons in the mesolimbic system.

The use of left heart bypass in adult and recurrent coarctation repair

OBJECTIVES

Paraplegia following coarctation repair occurs in 0.4% of infants. However, for older children, adults and re-operations, the incidence can be as high as 2.6%. Yet there is no consensus on the need for spinal cord protection or the optimal method. This paper reports our experience with left heart bypass (LHB) in adult and re-do coarctation.

METHODS

Between 1997 and 2000, nine patients underwent elective resection of coarctation (three re-dos, two balloons) with a mean age of 17.9 years (range, 8-44) and weight of 52 kg (range, 17.3-109). The mean trans-coarctation gradient was 29.6 mmHg (range, 20-45). Patients were placed on LHB using a centrifugal pump with full heparinization through a fourth-space thoracotomy. Patients were cooled to 31-34 degrees C for additional spinal cord protection. Repair was carried out with an inter-positional graft (5/9), a Gore-Tex patch (2/9) or end-to-end anastomosis (2/9). The mean cross-clamp and bypass times were 36.4 (range, 19-65) and 40.3 min (range, 22-70), respectively.

RESULTS

No patient developed transient or permanent paraplegia. The mean peak creatinine was 80 micromol/l (range, 51-123).

CONCLUSIONS

LHB is simple, easy and safe to implement, and is the only technique capable of maintaining independent upper and lower body perfusion pressure. Potentially, it provides the best spinal cord protection, and extends the margin of safety and time to execute an accurate repair.

Microbial glycosyltransferases for carbohydrate synthesis: alpha-2,3-sialyltransferase from Neisseria gonorrheae

The alpha-2,3-sialyltransferase from Neisseria gonorrheae was overproduced in E. coli for exploitation of its substrate specificity and synthetic utility. Several potential acceptor substrates were synthesized in this study, including mono- and oligosaccharides, glycolipids, and glycopeptides and their sulfate derivatives. Some CMP-sialic acid derivatives with modification at the C-5 position were also prepared for evaluation as donor substrates. It was found that the enzyme exhibits a broader acceptor substrate specificity when compared to other sialyltransferases, though the donor specificity is quite limited. Application of the enzyme to the preparative synthesis of representative sialyl glycoconjugates has been demonstrated. On the basis of this work and the work of others, this enzyme is the most versatile and synthetically useful among all sialyltransferases known to date, especially for the synthesis of sulfate-containing glycoconjugates.

Combinatorial library of five-membered iminocyclitol and the inhibitory activities against glyco-enzymes

BACKGROUND

Oligosaccharide processing enzymes are important classes of catalysts involved in synthesizing specific oligosaccharide structures on proteins and sphingolipids. Development of specific inhibitors of such enzymes is of current interest as these inhibitors may be used to control cellular functions. Five-membered iminocyclitols have been shown to be potent inhibitors of such enzymes. Since a rational design and synthesis of inhibitors is often extremely difficult due to the limited information regarding the structure of the active site, we carried out a combinatorial library approach.

RESULTS

To create diversity, we decided to use an aldehyde group of a protected iminocyclitol for reductive amination and the Strecker reaction. After transformation of the nitrile group introduced by the Strecker reaction into an amine and amide and complete deprotection, a small library of five-membered iminocyclitols consisting of 27 compounds was synthesized. A series of compounds obtained by reductive amination was first screened as potential inhibitors of glycosidases and glycosyltransferases. Among them, compounds carrying a C(10)-alkyl group showed marked enhancement of inhibitory activity against alpha-mannosidase at 10 microM concentration when compared with its parent compound and deoxymannojirimycin. Furthermore, compounds having the phenylethyl group showed an extremely strong inhibitory effect against alpha-galactosaminidase at a K(i) value of 29.4 nM. Compounds with an aminomethyl and amide group at the C-1' position of these two molecules showed a decrease in inhibitory activities.

CONCLUSIONS

A combinatorial approach based on five-membered iminocyclitols with a galacto-configuration was exploited. The potential usefulness of the library as a source of inhibitors of glycoenzymes is clearly shown in this study.

Observation of covalent intermediates in an enzyme mechanism at atomic resolution

In classical enzymology, intermediates and transition states in a catalytic mechanism are usually inferred from a series of biochemical experiments. Here, we derive an enzyme mechanism from true atomic-resolution x-ray structures of reaction intermediates. Two ultra-high resolution structures of wild-type and mutant d-2-deoxyribose-5-phosphate (DRP) aldolase complexes with DRP at 1.05 and 1.10 angstroms unambiguously identify the postulated covalent carbinolamine and Schiff base intermediates in the aldolase mechanism. In combination with site-directed mutagenesis and (1)H nuclear magnetic resonance, we can now propose how the heretofore elusive C-2 proton abstraction step and the overall stereochemical course are accomplished. A proton relay system appears to activate a conserved active-site water that functions as the critical mediator for proton transfer.

Structure-activity studies of FIV and HIV protease inhibitors containing allophenylnorstatine

The interaction of P1 and P3 side chains with the combining S1 and S3 hydrophobic subsites of HIV and FIV proteases has been explored using asymmetric competitive inhibitors. The inhibitors evaluated contained (2S,3S)-3-amino-2-hydroxy-4-phenylbutyric acid (allophenylnorstatine) as the hydroxymethylcarbonyl isostere, (R)-5,5-dimethyl-1, 3-thiazolidine-4-carbonyl as P1', Val as P2 and P2' residues, and a variety of amino acids at the P3 and P3' positions. All inhibitors showed competitive inhibition of both enzymes with higher potency against the HIV protease in vitro. Within this series, 31 (VLE776) is the most effective inhibitor against FIV protease, and it contains Phe at P3, but no P3' residue. VLE776 also exhibited potent antiviral activities against the drug-resistant HIV mutants (G48V and V82F) and the TL3-resistant HIV mutants. Explanation of the inhibition activities was described. In addition, a new strategy was described for development of bifunctional inhibitors, which combine the protease inhibitor and another enzyme inhibitor in one molecule.

Viral evolution in response to the broad-based retroviral protease inhibitor TL-3

TL-3 is a protease inhibitor developed using the feline immunodeficiency virus protease as a model. It has been shown to efficiently inhibit replication of human, simian, and feline immunodeficiency viruses and therefore has broad-based activity. We now demonstrate that TL-3 efficiently inhibits the replication of 6 of 12 isolates with confirmed resistance mutations to known protease inhibitors. To dissect the spectrum of molecular changes in protease and viral properties associated with resistance to TL-3, a panel of chronological in vitro escape variants was generated. We have virologically and biochemically characterized mutants with one (V82A), three (M46I/F53L/V82A), or six (L24I/M46I/F53L/L63P/V77I/V82A) changes in the protease and structurally modeled the protease mutant containing six changes. Virus containing six changes was found to be 17-fold more resistant to TL-3 in cell culture than was wild-type virus but maintained similar in vitro replication kinetics compared to the wild-type virus. Analyses of enzyme activity of protease variants with one, three, and six changes indicated that these enzymes, compared to wild-type protease, retained 40, 47, and 61% activity, respectively. These results suggest that deficient protease enzymatic activity is sufficient for function, and the observed protease restoration might imply a selective advantage, at least in vitro, for increased protease activity.

Synthesis of solid-supported mirror-image sugars: a novel method for selecting receptors for cellular-surface carbohydrates

We introduced a novel method, through mirror-image phage display, for the identification of high-affinity D-peptides to target specific cell-surface carbohydrates. Both 3-deoxy-alpha-L-manno-2-octulosonic acid (L-KDO) and L-sialic acid and an L-sialo-disaccharide have been synthesized and attached to a solid support for selection of high-affinity peptide binders displayed on phages. Our initial studies in this effort produce single-chain Fab sequences and dodecapeptides that bind to sialic acid and KDO with nanomolar and high micromolar affinity.

Hexosaminidase inhibitors as new drug candidates for the therapy of osteoarthritis

BACKGROUND

Articular cartilage from patients with osteoarthritis is characterized by a decreased concentration and reduced size of glycosaminoglycans. Degeneration of the cartilage matrix is a multifactorial process, which is due in part to accelerated glycosaminoglycan catabolism. Recently, we have demonstrated that hexosaminidase represents the dominant glycosaminoglycan-degrading glycosidase released by chondrocytes into the extracellular compartment and is the dominant glycosidase in synovial fluid from patients with osteoarthritis. Inhibition of hexosaminidase activity may represent a novel approach to the prevention of cartilage matrix glycosaminoglycan degradation and a potentially new strategy to treat osteoarthritis.

RESULTS

We have synthesized and investigated a series of iminocyclitols designed as transition-state analog inhibitors of human hexosaminidase, and demonstrated that the five-membered iminocyclitol 4 expresses the strongest inhibitory activity with K(i)=24 nM. Inhibition of hexosaminidase activity in human cultured articular chondrocytes and human chondrosarcoma cells with iminocyclitol 4 resulted in accumulation of hyaluronic acid and sulfated glycosaminoglycans in the cell-associated fraction. Similarly, incubation of human cartilage tissue with iminocyclitol 4 resulted in an accumulation of glycosaminoglycans in the pericellular compartment.

CONCLUSIONS

Inhibition of hexosaminidase activity represents a new strategy for preventing or even reversing cartilage degradation in patients with osteoarthritis.