Metadynamics molecular dynamics and isothermal Brownian-type molecular dynamics simulations for the chiral cluster Au18

In an effort to gain insight into enantiomeric transitions, their transition mechanism, time span of transitions and distribution of time spans etc, we performed molecular dynamics (MD) simulations on chiral clusters Au₁₀, Au₁₅and Au₁₈, and found that viable reaction coordinates can be deduced from simulation data for enlightening the enantiomeric dynamics for Au₁₀and Au₁₅, but not so for Au₁₈. The failure in translating the Au₁₈-L ⇌ Au₁₈-R transitions by MD simulations has been chalked up to the thermal energyk_BTat 300 K being much lower than energy barriers separating the enantiomers of Au₁₈. Two simulation strategies were taken to resolve this simulation impediment. The first one uses the well-tempered metadynamics MD (MMD) simulation, and the second one adeptly applies first a somewhat crude MMD simulation to locate a highly symmetrical isomer Au_18Sand subsequently employed it as initial configuration in the MD simulation. In both strategies, we work in collective variable space of lower dimensionality. The well-tempered MMD simulation tactic was carried out aiming to offer a direct verification of Au₁₈enantiomers, while the tactic to conduct MMD/MD simulations in two consecutive simulation steps was intended to provide an indirect evidence of the existence of enantiomers of Au₁₈given that energy barriers separating them are much higher than ca.k_BTat 300 K. This second tactic, in addition to confirming indirectly Au₁₈-L and Au₁₈-R starting from the symmetrical cluster Au_18S, the simulation results shed light also on the mechanism akin to associative/nonassociative reaction transitions.

Development and structural characterisation of human scFv targeting MDM2 spliced variant MDM215kDa

The murine double minute 2 (MDM2) protein is a major negative regulator of the tumour suppressor protein p53. Under normal conditions, MDM2 constantly binds to p53 transactivation domain and/or ubiquinates p53 via its role as E3 ubiquitin ligase to promote p53 degradation as well as nuclear export to maintain p53 levels in cells. Meanwhile, amplification of MDM2 and appearance of MDM2 spliced variants occur in many tumours and normal tissues making it a prognostic indicator for human cancers. The mutation or deletion of p53 protein in half of human cancers inactivates its tumour suppressor activity. However, cancers with wild type p53 have its function effectively inhibited through direct interaction with MDM2 oncoprotein. Here, we described the construction of a MDM2 spliced variant (rMDM2^15kDa) consisting of SWIB/MDM2 domain and its central region for antibody generation. Biopanning with a human naïve scFv library generated four scFv clones specific to rMDM2^15kDa. Additionally, the selected scFv clones were able to bind to the recombinant full length MDM2 (rMDM2-FL). Computational prediction showed that the selected scFv clones potentially bind to exon 7-8 of MDM2 while leaving the MDM2/SWIB domain free for p53 interaction. The developed antibodies exhibit good specificity can be further investigated for downstream biomedical and research applications.

Development of a Phage Display Panning Strategy Utilizing Crude Antigens: Isolation of MERS-CoV Nucleoprotein human antibodies

Antibody phage display has been pivotal in the quest to generate human monoclonal antibodies for biomedical and research applications. Target antigen preparation is a main bottleneck associated with the panning process. This includes production complexity, downstream purification, quality and yield. In many instances, purified antigens are preferred for panning but this may not be possible for certain difficult target antigens. Here, we describe an improved procedure of affinity selection against crude or non-purified antigen by saturation of non-binders with blocking agents to promote positive binder enrichment termed as Yin-Yang panning. A naïve human scFv library with kappa light chain repertoire with a library size of 109 was developed. The improved Yin-Yang biopanning process was able to enrich monoclonal antibodies specific to the MERS-CoV nucleoprotein. Three unique monoclonal antibodies were isolated in the process. The Yin-Yang biopanning method highlights the possibility of utilizing crude antigens for the isolation of monoclonal antibodies by phage display.

Cognizance of Molecular Methods for the Generation of Mutagenic Phage Display Antibody Libraries for Affinity Maturation

Antibodies leverage on their unique architecture to bind with an array of antigens. The strength of interaction has a direct relation to the affinity of the antibodies towards the antigen. In vivo affinity maturation is performed through multiple rounds of somatic hypermutation and selection in the germinal centre. This unique process involves intricate sequence rearrangements at the gene level via molecular mechanisms. The emergence of in vitro display technologies, mainly phage display and recombinant DNA technology, has helped revolutionize the way antibody improvements are being carried out in the laboratory. The adaptation of molecular approaches in vitro to replicate the in vivo processes has allowed for improvements in the way recombinant antibodies are designed and tuned. Combinatorial libraries, consisting of a myriad of possible antibodies, are capable of replicating the diversity of the natural human antibody repertoire. The isolation of target-specific antibodies with specific affinity characteristics can also be accomplished through modification of stringent protocols. Despite the ability to screen and select for high-affinity binders, some 'fine tuning' may be required to enhance antibody binding in terms of its affinity. This review will provide a brief account of phage display technology used for antibody generation followed by a summary of different combinatorial library characteristics. The review will focus on available strategies, which include molecular approaches, next generation sequencing, and in silico approaches used for antibody affinity maturation in both therapeutic and diagnostic applications.

Infections in hospitalized lupus nephritis patients: characteristics, risk factors, and outcomes

Background There are limited studies documenting infection epidemiology in lupus nephritis (LN) patients. We aimed to study infection incidences and risk characteristics and ascertain possible predictors of infective outcomes in a multiethnic Asian population. Methods This retrospective study from 2006 to 2012 included newly diagnosed LN patients. We collected admissions, immunosuppression, and infection data until end-stage renal failure, death, last follow-up, or the year 2015. The infection incidence rates were evaluated and a generalized linear latent and mixed models (GLLAMM) analysis was carried out to evaluate potential predictors of infection. Results Our cohort of 101 patients consisted of mainly Chinese (75.2%), females (78.2%), and a median age of 38 years (IQR 26-49). The median time of follow-up was 72.8 months (IQR 49.5-94.0). Six out of 14 patient deaths were infection related. Seventy-eight out of 200 admissions, with a total of 102 episodes of infection, occurred in 46 patients. The incidence of infection rates leading to admissions was 10.3 per 100 person-years and the incidence of infection episodes rates was 17.6 per 100 person-years. Cytomegalovirus (CMV) was the most common organism identified. Univariate GLLAMM analysis showed Malay compared to Chinese ethnicity (HR 2.833 (95% CI 1.088-7.373)), use of oral cyclophosphamide (HR 6.618 (95% CI 1.015-43.154)) and rituximab (HR 3.967 (95% CI 1.157-13.603)) as predictors of infection-related admissions. Malay ethnicity and rituximab remained significant in the multivariate GLLAMM analysis. Conclusions Our study highlights substantial infection incidences in patients with LN and its contribution to deaths.

Ancient schwannoma of cervical sympathetic chain masquerading as carotid body tumour

Schwannoma of cervical sympathetic chain is a rare cause of neck swelling. We report a 73- year-old male presented with anterior neck triangle swelling mimicking a carotid body tumour. Surgical excision was done, and the histopathological examination reported as ancient schwannoma. We would like to discuss the important differential diagnoses and highlight the possibility of an ancient schwannoma of cervical sympathetic chain masquerading as carotid body tumour. Also, to emphasise the importance of imaging for pre-operative planning and counselling.

Carotid dosimetry for T1 glottic cancer radiotherapy

OBJECTIVE

Radiotherapy for T1 glottic cancer is commonly delivered using a lateral parallel opposed pair of megavoltage photon fields. There is increasing reported evidence of cerebrovascular events due to radiation-induced carotid stenosis. An alternative field arrangement is to use an anterior oblique technique. This study compares the carotid dosimetry between the two techniques and reviews the evidence for the risk of radiation-induced vascular events.

METHODS

The radiotherapy plans of 10 patients with T1 glottic cancer treated with an anterior oblique technique were examined for carotid dose. Alternative plans were then created using a parallel opposed pair of fields and the dose to the carotids compared. All patients received 50 Gy in 16 fractions treating once daily, for 5 days in a week.

RESULTS

The average of the mean dose to the carotids with the anterior oblique technique was 21 Gy compared with 37 Gy using the lateral parallel opposed pair arrangement (p < 0.0001).

CONCLUSION

An anterior oblique field arrangement for the treatment of T1 glottic cancer results in a significantly lower radiation dose to the carotid arteries, which may be clinically important in terms of reducing the risk of cerebrovascular events in long-term survivors.

ADVANCES IN KNOWLEDGE

Although the anterior oblique technique for treating early glottic cancers is well described, and it is predictable that the dose received by the carotid arteries should be lower with this technique, to our knowledge this is the first study to quantify that reduction in dose with a series of patients.

A positive anti-nuclear antibody result does not contraindicate living kidney donation

Autoantibodies may precede the clinical onset of disease in up to two-thirds of patients with systemic lupus erythematosus (SLE). There is thus concern that antinuclear antibody (ANA) positivity in living kidney donors may eventuate in development of lupus nephritis post-uninephrectomy. Post-uninephrectomy, we routinely examine living kidney donors at 6 weeks, 6 months, 12 months, and annually thereafter. We performed a retrospective review of living kidney donors who had undergone uninephrectomy between July 1, 1999, and December 1, 2008. Data were collected for pre- and post-uninephrectomy renal function, proteinuria, hematuria, ANA, and anti-double stranded deoxyribonucleic acid (anti-dsDNA) antibodies. Among 68 living donor uninephrectomies performed during the study period, we excluded patients with no pre- uninephrectomy ANA or defaulted postoperative follow-up (n = 2). Twelve (18.2%) living donors were ANA-positive (M:F = 4:8) with a median titer of 1:100 (range, 1:100-1:800); 1 was transiently anti-dsDNA-positive. There were no significant differences between ANA-positive and ANA-negative donors in baseline demographics or pre-uninephrectomy creatinine clearance (median 108.0, range 79-179 mL/min vs. 106, range 58-172 mL/min, P = NS). Only 1 ANA-positive patient displayed transient microscopic hematuria (8 red blood cells); none had proteinuria pre-nephrectomy. Median follow-up was 63.5 (range, 21.2-139.3) months. At last clinic review, none of the ANA-positive donors had developed clinical symptoms or signs of SLE. Comparing ANA-positive and ANA-negative live donors at 5 years post-uninephrectomy, there were no significant differences in creatinine clearance (median 86.5, range 67-112 mL/min vs. 85.0, range 35-154 mL/min, P = NS), total urine protein (median 0, range 0-0.196 g/24 h vs 0, range 0-0.190 g/24 h, P = NS), or presence of hematuria (16.7% vs 33.3%, P = NS). Isolated ANA positivity does not contraindicate living kidney donation. Up to 5 years post- uninephrectomy, the risk of developing clinical lupus among low-titer ANA-positive individuals remains low.

Ferromagnetism in dilute magnetic semiconductors through defect engineering: Li-doped ZnO

We demonstrate, both theoretically and experimentally, that cation vacancy can be the origin of ferromagnetism in intrinsic dilute magnetic semiconductors. The vacancies can be controlled to tune the ferromagnetism. Using Li-doped ZnO as an example, we found that while Li itself is nonmagnetic, it generates holes in ZnO, and its presence reduces the formation energy of Zn vacancy, and thereby stabilizes the zinc vacancy. Room temperature ferromagnetism with p type conduction was observed in pulsed laser deposited ZnO:Li films with certain doping concentration and oxygen partial pressure.

'Moya' than meets the eye: neurofibromatosis type 1 associated with Moyamoya syndrome

Moyamoya syndrome (MMS) is an uncommon association of neurofibromatosis type 1 (NF1). We describe a seven-year-old chinese girl with NF1 and unilateral MMS with multiple hyperintensities on T2-weighted magnetic resonance (MR) images. The ischaemic lesions in the ipsilateral white matter were hypointense on fluid attenuated inversion recovery (FLAIR) MR images, in contrast to the hyperintense "unidentified bright objects" (UBOs) of NF1. Neuroradiologists should be aware of associated MMS in NF1 patients, and distinguish the effects of ischaemia from UBOs, especially on FLAIR MR imaging.

Ex-vivo NMR of unprocessed tissue in water: a simplified procedure for studying intracranial neoplasms

Ex-vivo and in-vitro nuclear magnetic resonance (NMR) spectroscopy techniques have been used for studying chemical metabolites in surgically resected specimens of human neoplasms, and may provide complementary information to in-vivo whole-body magnetic-resonance spectroscopy (MRS). We describe an ex-vivo NMR in water method for measurement of water-soluble metabolites in unprocessed normal rat brain tissue and human intracranial neoplasms. The NMR spectra obtained using the method described here were comparable to those obtained using high-resolution magic-angle spinning (HRMAS) NMR methods, with good correlation in metabolite concentrations relative to creatine (r2 = 0.7635). Improved spectral resolution and baseline were noted compared to HRMAS, but macromolecule resonances were not detected. Ex-vivo NMR of unprocessed tissue in water is rapid and technically simple to perform, and has the potential to be used for direct assessment of intracranial neoplasms.

Negative specific heat in a quasi-2D generalized vorticity model

Negative specific heat is a dramatic phenomenon where processes decrease in temperature when adding energy. It has been observed in gravo-thermal collapse of globular clusters. We now report finding this phenomenon in bundles of nearly parallel, periodic, single-sign generalized vortex filaments in the electron magnetohydrodynamic model for the unbounded plane under strong magnetic confinement. We derive the specific heat using a steepest-descent method and a mean-field property. Our derivations show that as temperature increases, the overall size of the system increases exponentially and the energy drops. The implication of negative specific heat is a runaway reaction, resulting in a collapsing inner core surrounded by an expanding halo of filaments.

Diffusion-weighted MR imaging in early diagnosis and prognosis of hypoglycemia

SUMMARY

We describe 2 cases of diffusion-weighted (DW) MR imaging in hypoglycemic coma. One patient, with diffuse cortical lesions, had a poor outcome, but the other, with transient white matter abnormalities, made a complete recovery. The distinctive patterns of DW MR imaging abnormalities in hypoglycemic patients should be recognized and may be a predictor of clinical outcome.

Endoscopic retrograde cholangiopancreatography in the elderly: outcomes, safety and complications

INTRODUCTION

As the population ages, the incidence of biliary tract pathologies also increases, leading to an increase in the demand for endoscopic retrograde cholangiopancreatography (ERCP) interventions. Our aims are to assess the outcomes, safety and complications associated with ERCP performed in an elderly population.

METHODS

Patients aged 80 years or over referred for ERCP from January 1999 to September 2002, were identified and retrospectively reviewed.

RESULTS

103 patients (68 females, mean age 84.6 +/- 3.9 years old) underwent 144 procedures (1-6 procedures/patient). The main indications were cholangitis (51.4 percent), choledocholithiasis (19.4 percent) and blocked stents (14.6 percent). Malignancies represented 5.6 percent of indications. The mean procedure time was 38 +/- 16 minutes. The overall success rate was 80.5 percent. Minor events occurred in 23 percent (tachycardia 13, desaturation six, transient hypotension six, self-limiting bleed four, extravasations three, and mild pancreatitis one). Major events were post sphincterotomy bleeding (five days post-procedure) one, duodenal perforation one (Billroth-II gastrectomy, survived after surgery), cholangitis two, and one death was probably procedure-related (acute myocardial event five days post-stenting in a patient with Klatskin tumour). Seven deaths occurred within one month of ERCP, due to advanced malignancies (four), sepsis (two) and acute myocardial infarction (one). Patients who died within one month had significantly higher serum urea (p-value equals 0.001), and creatinine (p-value equals 0.007) levels, and lower haemoglobin (p-value equals 0.014) level. More patients had an underlying malignancy (p-value less than 0.001). In addition, they were given significantly less conscious sedation (midazolam [p-value equals 0.002] and fentanyl [p-value equals 0.018]).

CONCLUSION

Our study showed that ERCP is safe in an elderly Asian population. Minor complications are usually transient and related to sedation, and mortality is usually related to severity of illness and underlying malignancies.

Clip-induced biliary stone

Surgical clip migration is a well-known phenomenon ever since their first use in surgery. The mechanism of clip migration is poorly understood, and can occur from days to years after laparoscopic cholecystectomy. Migration of the surgical clips may be a complex process involving necrosis, pressure exerted from intra-abdominal movement, formation of stones over the exposed clip within the bile duct, and eventual migration into the common bile duct. We report two cases, a 58-year-old man and a 54-year-old woman, of clip- induced biliary stones resulting from surgical clip migration a few years after laparoscopic cholecystectomy.

Abnormal liver function tests in the symptomatic pregnant patient: the local experience in Singapore

INTRODUCTION

The causes of abnormal liver function tests in pregnancy are varied and may or may not be pregnancy-related. Often, the diagnosis can be difficult. This study looked at the causes of deranged liver function tests in obstetric patients with significant symptoms and signs.

MATERIALS AND METHODS

Data from 50 cases of abnormal liver function tests in pregnant patients, who presented from 1998 to 2001, were analysed. Their presenting symptoms included persistent vomiting (48%), pruritus (14%), jaundice (26%), upper abdominal discomfort (24%) and hypertension (46%).

RESULTS

Pregnancy-related causes accounted for 84% of the abnormal liver function tests. Abnormal liver function tests occurred more frequently in the first (34%) and third (58%) trimesters than in the second trimester (8%). Hyperemesis gravidarum (94%) and partial haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome (31%) were the commonest causes in the first and third trimesters respectively. Hepatitis B flare resulted in 2 maternal deaths. Seven patients with pre-eclampsia toxaemia, acute fatty liver of pregnancy or partial/complete HELLP syndrome had their liver function tests measured sequentially before and after delivery. All of them showed rapid improvement postpartum with their alanine aminotransferase (ALT) dropping 50% within 3 days.

CONCLUSIONS

The majority of patients with abnormal liver function tests had a cause related to pregnancy, and pregnancy-related causes in the third trimester improved rapidly postpartum. Hepatitis B flare was a significant non-obstetric cause leading to maternal mortality. This diagnosis must therefore be considered in ethnic groups where the incidence of chronic hepatitis B infection is high, especially in chronic hepatitis B carriers with suspected pregnancy-related disease who deteriorate postpartum.

Advanced disseminated gastric carcinoma in pregnancy

Gastric cancers associated with pregnancy are rare and often diagnosed at advanced stages where curative therapies are not possible. The outcomes have generally been very poor with death occurring within months of diagnosis. Suspicion and early endoscopy are necessary for early diagnosis. We herein report a case of advanced disseminated gastric cancer presenting in the third trimester with pre-eclampsia and death occurring less than a month after diagnosis.

Diffusion-weighted MR imaging in intracranial infections

INTRODUCTION

Diffusion-weighted magnetic resonance (MR) imaging (DWMRI) is valuable in the assessment of acute cerebral infarction and may be useful for other diseases of the central nervous system (CNS). In this study, we present the DWMRI appearance of intracranial infection.

MATERIALS AND METHODS

Thirty patients with clinical diagnosis of CNS infection were reviewed. All patients underwent conventional contrast-enhanced MR examination and DWMRI using single-shot echo-planar imaging at b = 1000 s/mm2.

RESULTS

Cerebral abscess, tuberculoma, subdural empyema and epidural abscess were hyperintense on DWMRI. Neurocysticercosis showed hypointense lesions on DWMRI. Four of 5 patients with encephalitis showed DWMRI hyperintensity; the appearance of toxoplasmosis lesions was variable. Patients suffering from meningitis without parenchymal involvement did not exhibit any abnormality of diffusion. One patient with tuberculous meningitis developed abnormality on DWMRI from acute cerebral infarction.

CONCLUSION

DWMRI increased lesion conspicuity and may be useful in assessment of cerebral infection. There were striking differences in the DWMRI appearances caused by different organisms and diseases.

Intracerebral schwannoma--a rare cause of epilepsy

INTRODUCTION

We report a case of schwannoma occurring in an intra-axial location causing seizures.

CLINICAL PICTURE

A 13-year-old girl presented with a 4-month history of seizures. Preoperative computed tomography scan and magnetic resonance imaging revealed an enhancing right frontal lobe tumour with surrounding oedema.

TREATMENT

The patient underwent craniotomy and a well-circumscribed tumour was completely resected. Histology with immunohistochemistry confirmed the diagnosis of an intracerebral schwannoma.

OUTCOME

The patient made a complete recovery and was seizure-free at 1-year follow-up.

CONCLUSION

Intracerebral schwannomas are rare, benign tumours. They may mimic astrocytomas or malignant tumours, and it is important to differentiate them from other neoplasms with less favourable outcomes. The neuroimaging features are, however, non-specific and definitive diagnosis can only be made on histology.

MRI findings in osmotic myelinolysis

OBJECTIVES

Osmotic myelinolysis is a distinctive clinical syndrome with characteristic CT and MR features. This study was undertaken to determine the MR appearance of these lesions on T1 and T2-weighted, and diffusion-weighted imaging (DWI) sequences with apparent diffusion coefficient (ADC) mapping.

MATERIALS AND METHODS

We describe six patients who presented with deranged serum sodium levels and subsequently developed osmotic myelinolysis. CT and MRI scans were retrospectively reviewed, including the advanced functional MR sequence of DWI with ADC mapping.

RESULTS

Both cerebral white matter and pontine lesions were typically hypo and hyper-intense on T1 and T2W sequences respectively. Lesions were mildly hyperintense on isotropic DWI images with elevation of the ADC.

CONCLUSION

MRI is superior to CT in depicting lesions in osmotic myelinolysis. DWI with ADC mapping suggests that osmotic myelinolysis is not simply a demyelinating disorder but has similarities to multiple sclerosis.

Categorical and prolonged potentials are evoked when brief, intermediate-intensity flashes stimulate horseshoe crab lateral eye photoreceptors during octopamine neuromodulation

Octopamine, a major efferent neurotransmitter in the lateral eye of the horseshoe crab (Limulus polyphemus), has previously been shown to modulate photoreceptor responses evoked by long flashes. Quantification of these data indicates that this modulation produced a genuine increase in sensitivity to light which cannot be entirely due to an increase in optical efficiency consequent on an anatomical alteration. Other previous studies demonstrated that extrinsic current can modulate Limulus lateral eye photoreceptor cells by inducing a bistable membrane potential with two distinct states. The present study was therefore undertaken to find out if octopamine could modulate visual responses by inducing prolonged and bistable polarization shifts similar to those demonstrated in several other neural systems. Intracellular microelectrodes were used to execute an electrophysiological study of the receptor potentials evoked in the lateral eye of Limulus when brief (20-ms) flashes were delivered while 50 microM octopamine perfused dark-adapted photoreceptors. The combined chemical and optical stimuli prolonged photoreceptor responses to light to the degree that they often exceeded the duration of the brief stimulus by hundreds of milliseconds. Moreover, these prolonged potentials were clearly bistable because they were categorical--either a prolongation was perceptually clear-cut and present or it was not, with no intermediate patterns being observed. During seawater control perfusions, such prolongations were absent. This appears to be the first demonstration of such categorical and prolonged potentials in a photoreceptor neuron. This finding particularly suggests that efferent-driven neuromodulation can enable the development of a persisting short-term representation of a brief stimulus, with this representation being retained at the most distal possible neural site.

High-throughput assessment of calcium sensitivity in skinned cardiac myocytes

Isolated permeabilized cardiac myocytes have been used in the study of myofilament calcium sensitivity through measurement of the isometric force-pCa curve. Determining this force-pCa relationship in skinned myocytes is relatively expensive and carries a high degree of variability. We therefore attempted to establish an alternative high-throughput method to measure calcium sensitivity in cardiac myocytes. With the use of commercially available software that allows for precise measurement of sarcomere spacing, we measured sarcomere length changes in unloaded skinned cardiac myocytes over a range of calcium concentrations. With the use of this technique, we were able to accurately detect acute increases or decreases in myofilament calcium sensitivity after exposure to 10 mM caffeine or 5 mM 2,3-butanedione monoxime, respectively. This technique allows for the simple and rapid determination of myofilament calcium sensitivity in cardiac myocytes in a reproducible and inexpensive manner and could be used for high-throughput screening of pharmacological agents and/or transgenic mouse models for changes in myofilament calcium sensitivity.

Targeted inactivation of Galpha(i) does not alter cardiac function or beta-adrenergic sensitivity

Inhibitory Galpha(i) protein increases in the myocardium during hypertrophy and has been associated with beta-adrenergic receptor (beta-AR) desensitization, contractile dysfunction, and progression of cardiac disease. The role of Galpha(i) proteins in mediating basal cardiac function and beta-AR response in nonpathological myocardium, however, is uncertain. Transgenic mice with targeted inactivation of Galpha(i2) or Galpha(i3) were examined for in vivo cardiac function with the use of conscious echocardiography and for ex vivo cardiac response to inotropic stimulation with the use of Langendorff blood-perfused isolated hearts and adult ventricular cardiomyocytes. Echocardiography revealed that percent fractional shortening and heart rate were similar among wild-type, Galpha(i2)-null, and Galpha(i3)-null mice. Comparable baseline diastolic and contractile performance was also observed in isolated hearts and isolated ventricular myocytes from wild-type mice and mice lacking Galpha(i) proteins. Isoproterenol infusion enhanced diastolic and contractile performance to a similar degree in wild-type, Galpha(i2)-null, and Galpha(i3)-null mice. These data demonstrate no observable role for inhibitory G proteins in mediating basal cardiac function or sensitivity to beta-AR stimulation in nonpathological myocardium.

Altered beta-adrenergic signal transduction in nonfailing hypertrophied myocytes from Dahl salt-sensitive rats

Desensitization of the beta-adrenergic receptor (beta-AR) response is well documented in hypertrophied hearts. We investigated whether beta-AR desensitization is also present at the cellular level in hypertrophied myocardium, as well as the physiological role of inhibitory G (G(i)) proteins and the L-type Ca(2+) channel in mediating beta-AR desensitization. Left ventricular (LV) myocytes were isolated from hypertrophied hearts of hypertensive Dahl salt-sensitive (DS) rats and nonhypertrophied hearts of normotensive salt-resistant (DR) rats. Cells were paced at a rate of 300 beats/min at 37 degrees C, and myocyte contractility and intracellular Ca(2+) concentration ([Ca(2+)](i)) were simultaneously measured. In response to increasing concentrations of isoproterenol, DR myocytes displayed a dose-dependent augmentation of cell shortening and the [Ca(2+)](i) transient amplitude, whereas hypertrophied DS myocytes had a blunted response of both cell shortening and the [Ca(2+)](i) transient amplitude. Interestingly, inhibition of G(i) proteins did not restore beta-AR desensitization in DS myocytes. The responses to increases in extracellular Ca(2+) and an L-type Ca(2+) channel agonist were also similar in both DS and DR myocytes. Isoproterenol-stimulated adenylyl cyclase activity, however, was blunted in hypertrophied myocytes. We concluded that compensated ventricular hypertrophy results in a blunted contractile response to beta-AR stimulation, which is present at the cellular level and independent of alterations in inhibitory G proteins and the L-type Ca(2+) channel.

Impaired cell shortening and relengthening with increased pacing frequency are intrinsic to the senescent mouse cardiomyocyte

Increased heart rate enhances cardiac contractility and accelerates relaxation. Both the force- and relaxation-frequency relationships are critical to myocardial function, especially during stress, and have been shown to be impaired in senescent myocardium. While senescent myocardium is characterized by decreased sarcoplasmic reticulum calcium ATPase activity, it is unclear if altered calcium regulation is directly responsible for the attenuated contractility and relaxation observed with increasing pacing frequency in aged myocardium. We examined this issue using freshly dissociated left ventricular myocytes, isolated from young adult and senescent mouse hearts. Myocytes were paced from 2 to 9 Hz at 37 degrees C, and cell shortening and [Ca(2+)](i)were simultaneously measured using video edge-detection and fura-2 fluorescence, respectively. In adult myocytes, increasing the pacing rate resulted in a progressive increase in percent cell shortening (CS) (P<0.01). This positive CS-frequency relationship was paralleled by an increase in [Ca(2+)](i)transient amplitude (P<0.05). In contrast, the CS-frequency relationship was blunted in senescent myocytes with no increase in percent CS or [Ca(2+)](i)transient amplitude with increasing pacing rate. With increased pacing, the decreases in time constants (tau) of cell relengthening and Ca(2+)transient decay were much steeper in adult compared to senescent myocytes (P<0.05). This study demonstrates that adult mouse myocytes exhibit augmented intracellular Ca(2+)transient amplitude and enhanced intracellular Ca(2+)removal with increasing pacing frequency, resulting in increased cell shortening and enhanced relengthening with frequency. In contrast, senescent mouse myocytes exhibit impaired calcium handling with increasing pacing frequency, which correlated with impairment of both cell shortening and relengthening.

A randomised trial of amoxycillin versus clarithromycin in combination with omeprazole for eradication of Helicobacter pylori infection in Singapore

Dual therapy has been reported to produce H.pylori eradication rate of 75-80%. This study is designed to determine the efficacy of omeprazole 20 mg bd in combination with amoxycillin 500 mg tid (Group A), amoxycillin 750 mg tds (Group B) and clarithromycin 500 mg tid (Group C) in Singapore. One hundred and forty-eight patients with H. pylori positive duodenal ulcers between ages of 22 and 69 were enrolled from two centres. There were 48 patients in Group A, 50 patients in Group B and 50 patients in Group C. The medication was given for 14 days. The patients were re-evaluated with an upper GI endoscope 4 weeks after cessation of treatment Successful eradication was defined as H.pylori negative on histology and culture. Based on intention to treat analysis, the eradication rate was 47.8% in Group A, 68% in Group B and 66% in Group C. The difference between GroupA and B were statistically significant (p = 0.04). Based on all patient treated analysis, the eradication rate was 57.5% in Group A, 70.7% in Group B and 75% in Group C. The difference in eradication rates was not statistically significant. Adverse events were reported in 21% of all patients with no difference in the adverse event rate between all groups. The eradication rate achieved with dual therapy in this study was similar to that attained in Western population. Higher dose amoxycillin regime gives a significantly higher eradication than a lower dose amoxycillin.

Negative association between T102C polymorphism at the 5-HT2A receptor gene and bipolar affective disorders in Singaporean Chinese

BACKGROUND

Serotonergic system abnormalities have been implicated in the pathogenesis of bipolar affective disorders. The 5-hydroxytryptamine type 2A (5HTR2A) receptor gene located on chromosome 13 (13q14-21) can be considered as a candidate gene for bipolar affective disorder (BPAD).

METHODS

Seventy-two patients with BPAD and 74 normal population controls were genotyped with restriction fragment length polymorphism (RFLP) in the 5HTR2A receptor gene.

RESULTS

We report a negative association between 5HTR2A receptor gene and BPAD. The association was examined using a case-control design. Allele and genotype frequencies as well as homozygote-heterozygote distribution at the 5HTR2A receptor gene polymorphism were compared between the two groups. There were no significant differences in the allelic or genotype frequencies and the homozygote-heterozygote distributions.

LIMITATIONS

Patients were recruited from one hospital in Singapore. The case-control study design needs replication.

CONCLUSION

Our finding indicates that the 5HTR2A receptor gene polymorphism is not a major factor in the genetic susceptibility to BPAD in Singaporean Chinese.

Comparison of hearts with 2 types of pressure-overload left ventricular hypertrophy

Comparisons of myocardium remodeled by the 2 most common causes of left ventricular hypertrophy (LVH), hypertension and aortic constriction, are limited. We hypothesized that important differences may exist in the myocardium of hearts with these 2 origins of "pressure overload" LVH. Accordingly, we studied isolated hearts from 3 groups of Dahl salt-sensitive rats, controls, and hearts with matched amounts of LVH secondary to either hypertension or aortic constriction. Isovolumic LV function and myocardial energetics ((31)P nuclear magnetic resonance spectroscopy) were measured as coronary flow was lowered to 16% of baseline for 48 minutes. During this low-flow ischemia, isovolumic end-diastolic pressure, a measure of LV stiffness, increased to 52+/-4 mm Hg in controls and 51+/-6 mm Hg in aortic banded hearts but to only 35+/-5 mm Hg in hearts with hypertensive LVH. In all hearts, the P(i) resonance in the (31)P nuclear magnetic resonance spectrum, whose position indicates myocardial pH, split into 2 peaks during low-flow ischemia, which indicates distinct regions of pH 6.9 (moderate acidosis) and pH 6.2 (severe acidosis). Concentrations of ATP, PCr, P(i), and H(+) of the moderately acidotic region were not different among groups. However, the size of the severely acidotic region was smallest in the hypertensive LVH hearts, and in all 3 groups, the size of this region correlated (r(2)=0.65 to 0.80) with the degree of LV stiffening. We conclude that in Dahl rats, LVH secondary to hypertension protects against ischemia-induced diastolic dysfunction by minimizing the size of the region of severe acidosis.

The alpha1/2 helical backbone of the prodomains defines the intrinsic inhibitory specificity in the cathepsin L-like cysteine protease subfamily

Proregions of papain-like cysteine proteases are potent and often highly selective inhibitors of their parental enzymes. The molecular basis of their selectivity is poorly understood. For two closely related members of the cathepsin L-like subfamily we established strong selectivity differences. The propeptide of cathepsin S was observed to inhibit cathepsin L with a K(i) of 0.08 nM, yet cathepsin L propeptide inhibited cathepsin S only poorly. To identify the respective structural correlates we engineered chimeric propeptides and compared their inhibitory specificity with the wild-types. Specificity resided in the N-terminal part, strongly suggesting that the backbone of the prodomain was the underlying structure.

Nipah viral encephalitis or Japanese encephalitis? MR findings in a new zoonotic disease

BACKGROUND AND PURPOSE

An epidemic of suspected Japanese encephalitis occurred in Malaysia in 1998-1999 among pig farmers. In neighboring Singapore, an outbreak occurred among pig slaughterhouse workers. It was subsequently established that the causative agent in the outbreak was not the Japanese encephalitis virus but a previously unknown Hendra-like paramyxovirus named Nipah virus.

METHODS

The brain MR images of eight patients with Nipah virus infection were reviewed. All patients tested negative for acute Japanese encephalitis virus. Seven patients had contrast-enhanced studies and six had diffusion-weighted examinations.

RESULTS

All patients had multiple small bilateral foci of T2 prolongation within the subcortical and deep white matter. The periventricular region and corpus callosum were also involved. In addition to white matter disease, five patients had cortical lesions, three had brain stem involvement, and a single thalamic lesion was detected in one patient. All lesions were less than 1 cm in maximum diameter. In five patients, diffusion-weighted images showed increased signal. Four patients had leptomeningeal enhancement and four had enhancement of parenchymal lesions.

CONCLUSION

The brain MR findings in patients infected with the newly discovered Nipah paramyxovirus are different from those of patients with Japanese encephalitis. In a zoonotic epidemic, this striking difference in the appearance and distribution of lesions is useful in differentiating these diseases. Diffusion-weighted imaging was advantageous in increasing lesion conspicuity.

Second trimester maternal serum hCG level in an Asian population: normal reference values by ultrasound dating

OBJECTIVE

To establish normative data of maternal serum chorionic gonadotropin (hCG) during the second trimester in an Asian population.

METHODS

We measured the maternal serum hCG levels in 17,955 normal singleton pregnancies between 15 and 21 weeks of gestation. The gestation age was estimated by measurement of fetal biparietal distance (BPD) in all cases. Median values of hCG at various gestational weeks were calculated and the values of hCG were converted to multiple of median (MoM). The incidences of low MoM value and high MoM value were also calculated.

RESULTS

The mean and median values of hCG were 57,153 mIU/ml and 50,120 mIU/ml, respectively, at 15 weeks of gestation and then decreased to 30,898 mIU/ml and 26,226 mIU/ml, respectively, at 21 weeks. We found 8.6% and 9.4% of normal singleton pregnancies have hCG MoM values >2.0 MoM and <0.5 MoM, respectively.

CONCLUSIONS

Our report provides a normal reference data of second trimester maternal hCG levels by ultrasound dating in an Asian population.

Impaired lusitropy-frequency in the aging mouse: role of Ca(2+)-handling proteins and effects of isoproterenol

We examined the relationship between age-associated lusitropic impairment, heart rate, and Ca(2+)-handling proteins and assessed the efficacy of increasing left ventricular (LV) relaxation via beta-adrenergic stimulation in adult and aging mouse hearts. LV function was measured in isolated, isovolumic blood-perfused hearts from adult (5 mo), old (24 mo), and senescent (34 mo) mice. Hearts were paced from 5 to 10 Hz, returned to 7 Hz, exposed to 10(-6) M isoproterenol, and paced again from 7 to 10 Hz. Age-related alterations in Na(+)/Ca(2+) exchanger (NCX), sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA2a), and phospholamban (PLB) levels were assessed by immunoblot. Despite preserved contractile performance, aging caused impaired lusitropy. Increased pacing caused an elevation in end-diastolic pressure that progressively worsened with age. The time constant of isovolumic pressure decay (tau) was significantly prolonged in old and senescent hearts compared with adults. Relative to adult hearts, the SERCA2a-to-PLB ratios were reduced 68 and 69%, and NCX were reduced 37 and 58% in old and senescent hearts, respectively. Isoproterenol completely reversed the age-associated lusitropic impairments. These data suggest that impaired lusitropy in aging mouse hearts is related to a decreased rate of cytosolic Ca(2+) removal and that accelerating SR Ca(2+) resequestration via beta-adrenergic stimulation can reverse this impairment.

Shear bond strength of repaired composite resins using a hybrid composite resin

The shear bond strength of different types of composite resins repaired with a hybrid composite was evaluated. The hybrid composite resin was repaired with itself as a control. The results of this study showed that the shear bond strength of the repair with most types of composite resins was minimally adequate.

Meningoencephalitis caused by a novel paramyxovirus: an advanced MRI case report in an emerging disease

Eleven abattoir workers in Singapore were infected in March 1999 by an outbreak caused by the Nipah virus. This newly discovered, Hendra-like paramyxovirus causes acute infection of the CNS. We present the magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (MRS) findings in a patient suffering from acute meningoencephalitis. Multiple small white matter lesions were detected on diffusion-weighted imaging (DWI) and T2-weighted images. There were no abnormalities detected on MRS. We believe this to be the first reported MRI findings in this novel zoonotic viral disease.

Mucocele involving the anterior clinoid process: MR and CT findings

We report two patients with surgically proved mucoceles involving the anterior clinoid process. One patient had a mucocele of an Onodi cell and the other had a mucocele isolated to the anterior clinoid process. The MR signal was increased on both T1- and T2-weighted images in the first patient but was isointense on both sequences in the second patient, a finding that resulted in misdiagnosis. The developmental and anatomic features, as well as the diagnostic pitfalls, are discussed.

The influence of finishing time on the marginal seal of a resin-modified glass-ionomer and polyacid-modified resin composite

The aim of this study was to compare the effect of immediate and delayed finishing on the microleakage of encapsulated resin-modified glass-ionomer, Fuji II LC and a polyacid-modified resin composite, Dyract compomer at both the enamel and dentine margins. Standardized Class V cavities were prepared along the cemento-enamel junction on buccal and palatal surfaces of 24 freshly extracted non-carious premolars. Equal numbers of buccal and palatal cavities in each group were restored with Fuji II LC and Dyract compomer following the manufacturer's instructions. The groups with delayed finishing were restored 1 week earlier, stored in saline at 37 degrees C and finished on the same day as the groups with immediate finishing. The specimens were then thermocycled 500 times and subjected to dye penetration testing. The results showed that both materials leaked more at the dentine than enamel margins for both regimes of finishing methods. There was no statistical difference in the microleakage of Dyract finished immediately or later at enamel and dentine margins and Fuji II LC finished immediately or later in dentine. However, a statistical difference existed between the microleakage in Fuji II LC finished immediately and later in enamel.

Effect of various infection-control methods for light-cure units on the cure of composite resins

This study (1) compared the curing-light intensity with various barrier infection-control methods used to prevent cross contamination, (2) compared the Knoop hardness value of cured composite resin when various barrier control methods were used, and (3) correlated the hardness of the composite resin with the light-intensity output when different infection-control methods were used. The light-cure unit tips were covered with barriers, such as cellophane wrap, plastic gloves, Steri-shields, and finger cots. The control group had no barrier. Composite resins were then cured for each of the five groups, and their Knoop hardness values recorded. The results showed that there was significant statistical difference in the light-intensity output among the five groups. However, there was no significant statistical difference in the Knoop hardness values among any of the groups. There was also no correlation between the Knoop hardness value of the composite resin with the light-intensity output and the different infection-control methods. Therefore, any of the five infection-control methods could be used as barriers for preventing cross-contamination of the light-cure unit tip, for the light-intensity output for all five groups exceeded the recommended value of 300 W/m2. However, to allow a greater margin of error in clinical situations, the authors recommend that the plastic glove or the cellophane wrap be used to wrap the light-cure tip, since these barriers allowed the highest light-intensity output.

Human sperm morphology and in vitro fertilization: sperm tail defects are prognostic for fertilization failure

The aim of this study was to determine the relationship between sperm morphology and fertilization rates in vitro. Semen samples were obtained from 50 couples undergoing IVF treatment. Sperm morphology was classified by strict criteria (Tygerberg) according to head, midpiece and tail defects in neat semen and after sperm selection by Percoll gradient centrifugation. Percoll preparation significantly increased the percentage of sperm with normal morphology from 13 to 20%. However, the greatest single regression coefficient was observed with the percentage of sperm with tail defects and correlated negatively with fertilization rates in vitro both before and after Percoll preparation. Therefore, tail morphology may be of value as a prognostic factor in assisted conception both before and after Percoll preparation.

Crohn's disease in the Singapore Chinese population

Crohn's disease (CD) is rare in the Chinese population, but lately there seems to be an increasing trend of CD in the Singapore Chinese population. We carried out a retrospective study of all Chinese patients with CD seen from 1987 to 1993 at the Singapore General Hospital. All patients were regularly followed up and treated. Disease activity was defined by the Organisation Mondiale de Gastroenterologie index. We also compared our series with our first series reported in 1987 and a Western series. There were 32 patients (20 men, 12 women) giving a hospital prevalence of 26.7 per 100,000 patients compared with 3.5 per 100,000 patients in 1986. The mean age was 37.1 years (range, 19-80 years). Twelve patients had small intestinal disease, 9 had colonic disease, and 11 had both. The common presenting symptoms were bloody diarrhea (67%), abdominal pain (53%), loss of weight (47%), and fever (34%). Extraintestinal manifestations were rare. Six patients had no relapse during the follow-up period, whereas the remaining 26 patients had an average of two relapses (range, 1-5). These relapses were complicated by fistulas in 8 patients and strictures in 11 patients. Response to steroids and sulfasalazine was good in most patients. Four patients required repeated surgery despite medical treatment. The prevalence of CD appears to be increasing among the Singapore Chinese population. The clinical features are similar to those of the Western population. Most of our patients responded to standard medical therapy, but further follow-up is needed to assess their long-term clinical outcome.

Endoscopic stenting in the management of biliary stones

INTRODUCTION

Endoscopic sphincterotomy and stenting are established modes of treatment in the management of bile duct stones and cholangitis. It is the first choice of treatment when the patients are elderly and have other medical conditions rendering them unfit for surgery.

AIMS

We studied the immediate and long-term outcome of endoscopic stenting in patients who underwent Endoscopic Retrograde Cholangiopancreatography (ERCP) for ductal stones.

PATIENTS AND METHODS

From January 1990 to December 1992, 366 patients had ERCP done for biliary stone disease. Fifty-five of these patients received a 10 French biliary stent for the treatment of bile duct stones. Most of these patients (60%) had an advanced age of more than 70 years and 45% had co-existing medical conditions rendering them high risk for surgery. Ninety-one percent had stones greater than 1.2 cm in diameter and 82% had multiple stones.

RESULTS

Eighty-nine percent of the patients had relief of jaundice and cholangitis resolved in 96% of the patients after stenting. None required immediate surgery after ERCP. Temporary bile drainage was achieved in 19 patients who went for surgery at a later date when they became more stable. Twenty-nine patients were on long-term follow-up for a mean period of 13 months. Nineteen patients still have their stents in place and remained well. The stents were repeatedly changed in 15 patients after an average duration of 5.5 months. Late complications were cholangitis in 2 patients and stent migration in one patient. There was no related mortality. In 5 patients, the stones have either disappeared spontaneously or become smaller and have been removed at subsequent ERCP.

CONCLUSION

Endoscopic stenting is a valuable alternative to surgical bile duct exploration. It can be the definitive mode of treatment for large or multiple bile duct stones in the elderly and patients with multiple medical problems who are unfit for surgery.

Spinal epidural non-Hodgkin's lymphoma: case reports of three patients presenting with spinal cord compression

Spinal epidural non-Hodgkin's lymphoma is an uncommon lesion. In this report, we describe three patients with a clinical picture of acute spinal cord compression as the first presentation of malignant lymphoma. The diagnosis was not suspected pre-operatively, and plain radiographs of the spine were either normal or not specific. Neuroimaging showed evidence of extradural soft tissue mass crossing multiple vertebral segments. In the light of these radiological findings, non-Hodgkin's lymphoma should be a diagnostic consideration in the older patient without prior history of malignancy who presents with a prodrome of back pain followed by spinal cord compression.

Marginal sealing ability of three cervical restorative systems

The purpose of this in vitro study was to evaluate the enamel and dentinal marginal sealing ability of three different cervical restorative systems. Class V preparations were made at the cementoenamel junction of 36 freshly extracted premolars. The teeth were randomly divided into three groups of 12 and restored with either a polyacid-modified resin composite ("compomer"), resin composite, or resin-modified glass-ionomer cement. The restored teeth were stored in saline at 37 degrees C for 1 week, thermally stressed for 500 cycles, and subjected to dye penetration testing. The results showed that there was no significant difference in dentinal margin sealing ability among the three materials evaluated. When the margins were in enamel, the resin composite restorations had significantly less leakage than did compomer or resin-modified glass-ionomer cement restorations. The marginal sealing ability of all three materials was significantly poorer in dentin than in enamel.

Roxatidine versus ranitidine in the treatment of duodenal ulcers: a randomized double-blind controlled multicentre study in Singapore

Roxatidine acetate, a new H2 receptor antagonist, was compared with ranitidine in the treatment of duodenal ulcers in a double-blind multicentre study. Eighty-four patients with endoscopically proven duodenal ulcer were randomized to receive 150 mg roxatidine acetate or 300 mg ranitidine at bedtime. Repeat endoscopy was performed after 4 weeks (25-33 days) and if the ulcer had not healed, another endoscopy was performed after a further 4 weeks of treatment. Using per protocol analysis 73.6% of ulcers treated with roxatidine healed at 4 weeks compared to 72.2% of ulcers treated with ranitidine (P = NS). The healing rates at 8 weeks were 92% with roxatidine and 83.3% with ranitidine (P = NS). Using equivalence tests, the healing rate of roxatidine was found to be equivalent to that of ranitidine within a 20% region. Roxatidine users took significantly less antacids than ranitidine users (P < 0.05). There were no significant adverse effects due to roxatidine or ranitidine. Roxatidine is a safe effective drug in the treatment of duodenal ulcers with a healing rate comparable to that of ranitidine.

Case selection for porcelain veneers

The options for correction of unesthetic teeth are numerous; among these treatments, porcelain veneers have received substantial attention from the profession and patients. The increase in dental health awareness and advances in dental materials and technology, such as the acid-etching technique, improved physical properties of composite luting resin, and the use of silane coupling agents, have contributed to the success ceramic veneers enjoy today. However, no single material or technique is without its limitations. This article therefore aims to review the criteria for case selection and the limitations of porcelain veneers in restorative dentistry.

A survey of the use of prostitutes (commercial sex workers) by new male attenders at a genito urinary medicine clinic

This study documents the use of prostitutes (commercial sex workers) by new male patients attending a genito urinary medicine clinic. 541 consecutive male patients completed an anonymous self-administered questionnaire. 48 (8.9%) gave a history of previous purchase of sexual services in Northern Ireland and/or elsewhere; 69% of these encounters occurred outside Northern Ireland. The largest group were single men aged 20-29 years. 87% of those who purchased services in Northern Ireland were asked by the prostitute to use a condom compared with 60% elsewhere, but there was no significant difference in actual condom use between both groups (66.7% vs 72.7%) Only 21% of patients who had purchased the services more than once used condoms consistently and 29% were willing to pay more for unprotected sexual intercourse. 40% attributed their attendance at this clinic directly or indirectly to their encounter with a prostitute. Encounters with prostitutes were often related to alcohol consumption, 88% sometimes or always purchasing these services after drinking alcohol. Despite widespread publicity at-risk behaviour involving unprotected sexual intercourse with prostitutes is not uncommon. Health education should be targeted at the young single male who travels outside Northern Ireland.

Role of ERCP in the management of bile duct lesions post bile duct surgery

INTRODUCTION

Therapeutic Endoscopic Retrograde Cholangio-Pancreatography (ERCP) is an established mode of treatment for bile duct lesions.

AIM

This paper reviews the role of ERCP in the management of bile duct lesions developing after biliary surgery.

PATIENTS AND METHODS

Of the 894 ERCPs performed in our department between January 1990 and May 1992, 23 (13 female, 10 male) were for patients with post-operative bile duct lesions. The mean age of these 23 patients was 59 years (range 38-91 years). The previous biliary surgical procedures were conventional cholecystectomy (n = 19), laparoscopic cholecystectomy (n = 3) and a cholecystectomy with choledochojejunostomy. Associated medical conditions of ischaemic heart disease, unstable angina, hypertensive heart disease, chronic obstructive airway disease and hepatitis B cirrhosis were present in 7 of these patients.

RESULTS

Ten patients had benign biliary strictures. Endoscopic stenting (with one or 2 stents) was successful in 9. The strictures reopened in 2 patients after a total stenting duration of 12 and 18 months respectively. Four patients had biliary leakages that were successfully treated with stenting. Two patients had spontaneous sealing of biliary leak at 3 and 6 months respectively. Nine patients had retained stones (7 with solitary stone, 2 with multiple stones) that were successfully removed with Dormia basket after sphincterotomy. Complications were few and manageable.

CONCLUSIONS

Therapeutic ERCP is safe and effective. It is a useful adjunct in the management of patients with post-operative biliary lesions.