Treatment of obstructive sleep apnea after chemoradiation therapy for advanced head and neck cancer

This report presents a case of worsening obstructive sleep apnea (OSA) post-chemoradiation therapy that improved significantly after placement of a hypoglossal nerve stimulator. The patient was a 66-year-old male, diagnosed with head and neck cancer, who experienced exacerbation of OSA after receiving chemoradiation. A hypoglossal nerve stimulator was placed, with minimal complications. The patient showed a significant improvement in OSA as exhibited by the reduction in apnea-hypopnea index. Hypoglossal nerve stimulator placement appears to be a potential treatment option for induced or worsened OSA, which is a known complication of head and neck cancer treatment. When considering treatment options, upper airway stimulation is indeed a possible method in patients who meet the recommended guideline criteria.

Clinical characteristic and management of haemophilia patients in Malaysia: A single centre experience

INTRODUCTION

Haemophilia is one of the commonest inherited bleeding disorders which may lead to long term disabilities if not treated properly. Our aim of study is to understand the clinical characteristic, treatment and complications of adult haemophilia patients in our centre.

MATERIALS AND METHODS

A retrospective cross-sectional review of all adult haemophilia A (HA) or haemophilia B (HB) patients who received treatment in Hospital Pulau Pinang from January 2021 to December 2022 was conducted. Data was retrieved from patients' medical records.

RESULTS

A total of 75 haemophilia patients (64 HA and 11 HB) were included in this study with median age of 37 years (range 19 70). 42 of them had severe haemophilia (50% of HA, 91% of HB). All HB and 93.8% of severe HA patients were on prophylaxis. Six severe and one mild HA patients developed inhibitor with four of them currently on non-factor prophylaxis. 24 patients (32%) had prior hepatitis C infection and all of them have been successfully treated. The mean annual bleeding rate for severe haemophilia patients were 1.77 (SD ±3.6). Target joints were observed in 9.3% of patients with ankle joint (71.4%) being the most affected joint. More than one quarter (26.7%) of our patients have comorbidities with majority of them having hypertension (17/20), followed by diabetes mellitus (5/20) and ischemic heart disease (5/20).

CONCLUSION

Our study showed that a significant number of adult patients with haemophilia have comorbidities. Apart from optimising factor replacement therapy, future planning should include improvement in screening, risk modification and prevention of cardiovascular disease.

Sustainable oil palm trunk fibre based activated carbon for the adsorption of methylene blue

Activated carbon (AC) is becoming the limelight due to its widespread application as an adsorbent for wastewater treatment, gases, and catalysis. However, its high consumption and price have drawn more attention to the sustainable use of natural resources as precursor for AC production. This study focuses on synthesising AC from two types of oil palm trunk (OPT) fibres, a significant agricultural waste products produced by Malaysia's thriving palm oil industries. The BET surface area of about 2057.9 m2 g-1 was achieved by chemical activation with phosphoric acid (H3PO4). The efficiency of the synthesised AC was critically analysed based on the adsorption experiments with methylene blue (MB) by varying several parameters (dosage of adsorbent, pH, initial dye concentration, and temperature of the solution) to elucidate the adsorption mechanism(s). A maximum adsorption capacity of 320.4 mg g-1 at 50 °C was achieved, and the Temkin (r2 = 0.98, 0.95, 0.95) and Langmuir (r2 = 0.94, 0.93, 0.95) isotherm models fitted the adsorption process better than the Freundlich (r2 = 0.95, 0.90, 0.86) model. Besides, the pseudo-second-order model (r2 > 0.90) best described the adsorption process, favouring chemisorption over physisorption. Thermodynamics showed MB adsorption on AC was spontaneous except at the highest dye concentration. It was exothermic at lower dye concentrations (50 and 100 mg L-1) and endothermic at higher ones (300, 500, and 700 mg L-1). In a nutshell, this study reveals that OPT fibre is a promising precursor for synthesising highly porous AC for the adsorption of MB dye.

Adhesive Capsulitis Secondary to COVID-19 Vaccination - A Case Series

Introduction

Shoulder injury related to vaccine administration (SIRVA) is a group of pathologies defined by pain and stiffness after intramuscular administration of vaccine to the upper arm and has been reported after COVID-19 vaccination. We aim to discuss its pathophysiology, clinical presentation, treatment and outcomes.

Materials and methods

We retrospectively identified patients presenting with adhesive capsulitis within four weeks of administration of COVID-19 vaccine to the affected arm at our tertiary institution from March 2021 to December 2022.

Result

Based on the above criteria, we identified seven cases of adhesive capsulitis, comprising one male and six female patients, with average age of 60 years. We present initial symptoms, signs and the duration from when the vaccine was administered. We have highlighted our treatment strategies as well as the clinical and functional outcomes reported by these patients after treatment. We have reported improvement in both Visual Analogue Scale (VAS) and range of motion (ROM) in all our patients after non-surgical management which included physiotherapy and, in some cases, hydrodilatation.

Conclusion

SIRVA related adhesive capsulitis is rare and under-reported with limited information in current literature. This study highlights that adhesive capsulitis is a potential complication arising from improper COVID-19 vaccine administration and reinforces traditional wisdom of administering vaccinations on the non-dominant arm. Conservative treatment strategies appear to be effective, particularly hydrodilatation combined with physiotherapy, and patients are expected to have a good return of function.

Activated carbon from biomass waste precursors: Factors affecting production and adsorption mechanism

The use of activated carbon is evidenced by the increased scope of carbon-based applications in various industrial applications including pharmaceutical antidotes, wastewater remediation, aquaculture and toxin removal. Activated carbon produced from biomass waste by various processing methods and conditions is emerging as a promising adsorbent for remediation of the ecosystem due to extensive discharge of pollutants. Methods of producing activated carbon, nature of lignocellulosic biomass waste, and interaction of adsorbent-adsorbate are some of the crucial factors that need to be scrutinized to produce an effective adsorbent. However, these factors have not been thoroughly discussed in the literature. Activated carbon needs to go through continuous and rigorous research and development through optimization of key parameters such as type of activation (physical/chemical) and processing conditions, especially for large-scale production. It is imperative to have a detailed understanding of the preeminent characteristics of the activated carbon such as pore size distribution, total pore volume, surface area, and yield of activated carbon that control the extents of adsorptions and production of activated carbon. To further clarify the involved mechanism, studies should focus on all the possible variables that influence the system. Therefore, this review provides a better understanding of factors that affect the production of an efficient activated carbon, important properties to be used as an adsorbent, and the involved mechanisms during the adsorption process followed by increasing demand for activated carbon in various fields.

Convalescent plasma as an adjunctive therapy for COVID-19: A single centre experience in Malaysia

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic posed a significant and urgent threat to global health and economy. Currently, there is no effective treatment known to alter the course of COVID-19. Convalescent plasma (CP) has been used previously to treat several types of infections during pandemics. The aim of our study is to evaluate the efficacy of CP in the treatment of severe COVID-19 infections at Hospital Sultanah Bahiyah, Kedah, Malaysia.

MATERIALS AND METHODS

A retrospective cross-sectional study of all severe COVID-19 patients who received CP treatment from 1st August 2020 until 31st December 2020 was conducted. Clinical outcomes were compared before and after CP transfusion.

RESULTS

Thirty-four patients were enrolled and received CP transfusion during the study period. The most common presenting complaints were fever (64.7%) and cough (58.8%). Fourteen patients showed improvement in oxygen support after CP transfusion. Several laboratory parameters also improved such as increased lymphocyte count (1.48 vs 1.98, p=0.008) and decreased C-reactive protein levels (28.1 vs 10.6, p=0.004), and these were statistically significant. Median time from symptoms onset to CP transfusion was 6 days (range 1-11) while median time from PCR diagnosis to CP transfusion was 5 days (range 1-11). One patient developed urticaria after CP transfusion and no severe adverse events were observed. Two of our patients passed away due to secondary causes.

CONCLUSION

This study showed CP treatment was well tolerated and could potentially prevent progression of COVID-19 to a severe disease if administered early during the viraemic phase. Further evaluation with randomized control trial should be conducted to help ascertain the optimal dose and effectiveness of CP treatment, in correlation with the IgG titer of the donated CP.

Dilemma in the management of methanol poisoning at a district hospital in Malaysia

There are increasing reports of methanol poisoning (MP) incidence worldwide. In Malaysia, the largest first methanol poisoning was reported in Selangor in 2013 with a total of 41 patients and cluster of cases been reported from the country since then. Often MP involved adulterated alcohol containing more than the legal permissible concentration of methanol. Methanol is rapidly absorbed and metabolised into formic acid which causes variable symptoms of the central nervous system such as blindness, seizure, coma and gastrointestinal disturbances. Mortality could reach up to 83% as reported using the coma state, pH and pCO2 level in the worst-case scenario.

Prevalence of endocrine complications in transfusion dependent thalassemia in Hospital Pulau Pinang: A pilot study

INTRODUCTION

Frequent blood transfusions results in iron overload and lead to multiple endocrine complications. In spite of improvements in iron chelation therapy, a significant number of transfusion dependent thalassaemia (TDT) patients still develop endocrine complications. The aim of this study is to evaluate the prevalence of various endocrine complications in our adult TDT patients and to study the correlation with serum ferritin and liver iron concentration (LIC).

METHODS

A retrospective review of all TDT patients treated in Haematology Unit, Hospital Pulau Pinang (HPP) was conducted.

RESULTS

Of the 45 adult TDT patients, 22 were males and 23 were females with mean age of 28.8±6.9 years old. Majority of TDT in HPP were beta thalassemia major (71.1%), followed by E-Beta thalassemia (24.4%) and HbH-Constant Spring (4.4%). Frequency of transfusion was 3-4 weekly. 40.0% of adult TDT suffered from at least one endocrine complication. Among the adult TDT patients with endocrine complication, 50% have one endocrinopathy, 38.9% with two types of endocrinopathies and 11.1% of them have three or more types of endocrinopathies. Hypogonadism (22.2%) was the commonest endocrine complication, followed by osteoporosis (20%), hypothyroidism (13.3%), diabetes mellitus (6.7%) and hypocortisolism (4.4%). Patients with endocrine complications were significantly older. Mean serum ferritin level and LIC was higher among patients with endocrine complications but both were not statistically significant.

CONCLUSION

Endocrinopathy is still prevalent in 40% of adult TDT patients. This leads to higher health-care resource utilization, cost and significant morbidities among patients with TDT. Therefore, regular monitoring and early detection with intensification of chelation therapy is essential.

Taeniasis and neurocysticercosis among Malaysians

Taeniasis, endemic in Southeast Asia, is caused by Taenia saginata (for beef) or Taenia solium and Taenia asiatica (for pork). T. solium also causes cysticercosis which can affect various organs. Taeniasis and cysticercosis cases are rarely reported in Malaysia. We report here two separate cases of beef taeniasis, and an interesting case of neurocysticercosis in a Malay Muslim. The taeniasis cases involved a Malaysian Chinese and a native Sabahan. Proglottids were recovered from them, and identification of the tapeworm done either from the microscopic examination of the egg or using PCR-based molecular diagnosis. Upon confirmation of taeniasis, both cases were given praziquantel and had been asymptomatic since. The neurocysticercosis case involving a Muslim who presented with seizure, was confirmed by histopathological examination of tissue sections taken from craniotomy excision of the brain lesion. He was given one month course of albendazole 400 mg bid and dexamethasone, and had been well and seizure free since. The two cases of taeniasis documented here had acquired the disease through eating raw or undercooked contaminated beef. For the neurocyticercosis case, it is suspected that he might have acquired the infection in one of his travels through human to human transmission via contaminated food or water consumption, given that Malaysia is not T. solium endemic area. Lastly praziquantel is an effective drug for beef taeniasis, while a combination of albendazole and dexamethasone work well for neurocysticercosis.

Intravenous C-Arm Conebeam CT Angiography following Long-Term Flow-Diverter Implantation: Technologic Evaluation and Preliminary Results

BACKGROUND AND PURPOSE

A noninvasive investigation with high spatial resolution and without metal artifacts is necessary for long-term imaging follow-up after flow-diverter implantation. We aimed to evaluate the diagnostic value of conebeam CT angiography with intravenous contrast enhancement in the assessment of vascular status following implantation of the Pipeline Embolization Device and to analyze the preliminary results of vascular status following long-term Pipeline Embolization Device implantation.

MATERIALS AND METHODS

This was an ongoing prospective study of consecutive patients with intracranial aneurysms treated with the Pipeline Embolization Device. Patients with a modified Rankin Scale score of 4-5 were excluded. The median and interquartile range of the time interval of Pipeline Embolization Device implantation to conebeam CT angiography with intravenous contrast enhancement were 56.6 and 42.9-62.4 months, respectively. Conebeam CT angiography with intravenous contrast enhancement was performed with the patient fully conscious, by using a C-arm CT with a flat panel detector.

RESULTS

There were 34 patients and 34 vascular segments. In all 34 cases, contrast effect and image quality were good and not substantially different from those of intra-arterial conebeam CTA. Metal artifacts occurred in all 14 cases with coil masses; the Pipeline Embolization Device was obscured in 3 cases. In all 34 cases, there was no residual aneurysm, no vascular occlusion, 1 vascular stenosis (50%), good Pipeline Embolization Device apposition to the vessel, and no Pipeline Embolization Device-induced calcification. All 28 Pipeline Embolization Device-covered side branches were patent.

CONCLUSIONS

Conebeam CT angiography with intravenous contrast enhancement is potentially promising and useful for effective evaluation of the vascular status following intracranial flow diverters. The Pipeline Embolization Device for intracranial aneurysms is probably safe and promising for long-term placement, with favorable morphologic outcome and without delayed complications.

A genome-wide analysis of the ultimate pH in swine

Meat pH is an important factor influencing meat quality traits in swine. This study evaluated a large number of genetic variants that covered all of the swine chromosomal regions. Approximately 68,000 single nucleotide polymorphisms (SNPs), found on Illumina Porcine SNP chips, were tested for associations with meat pH values. A genome-wide association study (GWAS) found that 19 SNPs on Sus scrofa chromosome 4 were significantly associated with pH. Two major candidate genomic regions were defined: a 1.08-Mb region (at nucleotide 30118313 to 31207050) contained 10 significant SNPs, based on an effect value of 5.0; and a 2.7-Mb genomic region (at nucleotide 73293076 to 76023681) contained 9 significant SNPs. Three putative genes--PKHD1L1, VCPIP1, and LOC102166532--were identified by GWAS near significant SNPs. These genes may account for variations in pH levels. Three pseudogenes and two non-coding RNAs were also detected by GWAS analysis. Estimations of expected and observed P values for pH revealed significant departures from the null hypothesis. A total of 9 haplotype blocks (HB) were constructed: HBs 1, 3, and 5 showed significant effects on pH24 and pH45, whereas an association was not confirmed between pH24 and HBs 4, 6, and 8. Findings from this study indicate that the three genes identified may influence pH of pig meat.

Novel SNPs in the growth arrest and DNA damage-inducible protein 45 alpha gene (GADD45A) associated with meat quality traits in Berkshire pigs

This study was conducted to evaluate the porcine gene GADD45A (growth arrest and DNA-damage-inducible protein 45 alpha) as a positional candidate controlling quantitative trait loci (QTL) for meat quality traits on chromosome 6 (SSC6). Four exons of the porcine GADD45A gene were defined from cDNA and BAC clone sequences. A total of 4 single nucleotide polymorphisms (SNPs) were identified in porcine GADD45A. The association of these SNPs (g.196A>G, g.392C>A, g.955T>C and g.3247A>T) with meat quality traits was evaluated in 678 Berkshire pigs. The genotype distribution of only one SNP (g.3247A>T) conformed to Hardy Weinberg equilibrium in the pig population analyzed in this study, and the other SNPs were not in Hardy-Weinberg equilibrium. All four SNPs were significantly associated with meat quality traits. Three SNPS (g.196A>G, g.392C>A, and g.955T>C) showed similar significant association patterns for drip loss, cooking loss, meat color (lightness; MC_L and yellowness; MC_B), shear force and water-holding capacity traits. By contrast, g.3247A>T had a different association pattern with other traits such as intramuscular fat content (IMF) and backfat thickness (BF), drip loss, MC_L, and moisture. These findings will provide useful information for genetic characterization or association studies in other pig populations. Additionally, these markers can potentially be applied in pig breeding programs to improve meat quality traits, including IMF and BF.

Molecular modelling, synthesis, cytotoxicity and anti-tumour mechanisms of 2-aryl-6-substituted quinazolinones as dual-targeted anti-cancer agents

BACKGROUND AND PURPOSE

Our previous study demonstrated that 6-(pyrrolidin-1-yl)-2-(3-methoxyphenyl)quinazolin-4-one (HMJ38) was a potent anti-tubulin agent. Here, HMJ38 was used as a lead compound to develop more potent anti-cancer agents and to examine the anti-cancer mechanisms.

EXPERIMENTAL APPROACH

Using computer-aided drug design, 2-aryl-6-substituted quinazolinones (MJ compounds) were designed and synthesized by introducing substituents at C-2 and C-6 positions of HMJ38. The cytotoxicity of MJ compounds towards human cancer cells was examined by Trypan blue exclusion assay. Microtubule distribution was visualized using TubulinTracker(TM) Green reagent. Protein expression of cell cycle regulators and JNK was assessed by Western blot analysis.

KEY RESULTS

Compounds MJ65-70 exhibited strong anti-proliferative effects towards melanoma M21, lung squamous carcinoma CH27, lung non-small carcinoma H460, hepatoma Hep3B and oral cancer HSC-3 cells, with one compund MJ66 (6-(pyrrolidin-1-yl)-2-(naphthalen-1-yl)quinazolin-4-one) highly active against M21 cells (IC50 about 0.033 μM). Treatment of CH27 or HSC-3 cells with MJ65-70 resulted in significant mitotic arrest accompanied by increasing multiple asters of microtubules. JNK protein expression was involved in the MJ65-70-induced CH27 and M21 cell death. Consistent with the cell cycle arrest at G2/M phase, marked increases in cyclin B1 and Bcl-2 phosphorylation were also observed, after treatment with MJ65-70.

CONCLUSIONS AND IMPLICATION

MJ65-70 are dual-targeted, tubulin- and JNK-binding, anti-cancer agents and induce cancer cell death through up-regulation of JNK and interfering in the dynamics of tubulin. Our work provides a new strategy and mechanism for developing dual-targeted anti-cancer drugs, contributing to clinical anti-cancer drug discovery and application.

Detection of quantitative trait Loci affecting fat deposition traits in pigs

Quantitative trait loci (QTL) associated with fat deposition traits in pigs are important gene positions in a chromosome that influence meat quality of pork. For QTL study, a three generation resource population was constructed from a cross between Korean native boars and Landrace sows. A total of 240 F2 animals from intercross of F1 were produced. 80 microsatellite markers covering chromosomes 1 to 10 were selected to genotype the resource population. Intervals between adjacent markers were approximately 19 cM. Linkage analysis was performed using CRIMAP software version 2.4 with a FIXED option to obtain the map distances. For QTL analysis, the public web-based software, QTL express (http://www.qtl.cap.ed.ac.uk) was used. Two significant and two suggestive QTL were identified on SSC 6, 7, and 8 as affecting body fat and IMF traits. For QTL affecting IMF, the most significant association was detected between marker sw71 and sw1881 on SSC 6, and a suggestive QTL was identified between sw268 and sw205 on SSC8. These QTL accounted for 26.58% and 12.31% of the phenotypic variance, respectively. A significant QTL affecting IMF was detected at position 105 cM between markers sw71 and sw1881 on SSC 6.

Intra-arterial revascularisation therapy for acute ischaemic stroke: initial experience in a Hong Kong hospital

OBJECTIVES

To assess the outcome of acute ischaemic stroke patients who received intra-arterial therapy in our unit.

DESIGN

Case series.

SETTING

A tertiary hospital in Hong Kong.

PATIENTS

Patients with ischaemic stroke due to large artery occlusion treated within 6 hours from symptom onset between January 2007 and May 2011.

INTERVENTION

Acute intra-arterial revascularisation therapy.

MAIN OUTCOME MEASURES

Primary outcome was functional independence (modified Rankin Scale score of ≤ 2) at 3 months. Secondary outcome was rate of recanalisation. Safety outcomes were symptomatic intracranial haemorrhage and 3-month mortality.

RESULTS

Twenty-one patients with a mean age of 67 years fulfilled the inclusion criteria. Their mean National Institutes of Health Stroke Scale score was 18. The mean onset-to-puncture time was 212 minutes. Nine received intra-arterial tissue plasminogen activator alone, 11 had an adjunctive mechanical thrombectomy, and one received balloon angioplasty without tissue plasminogen activator. At the end of the procedure, thrombolysis grade 2a or better was attained in 18 (86%) of the patients, and 8 (38%) achieved functional independence at 3 months. Rates of symptomatic intracranial haemorrhage and 3-month mortality were 10% and 24%, respectively.

CONCLUSION

In this setting, intra-arterial revascularisation therapy appeared safe and efficacious for this selected group of ischaemic stroke patients with large artery occlusions. Experience gained from this pilot study may help improve clinical outcomes of such patients.

Genetic variation of FASN is associated with fatty acid composition of Hanwoo

The objective of this study was to identify genetic variants in the bovine fatty acid synthase (FASN) gene and to evaluate associations with fatty acid composition from longissimus lumborum muscle using 90 purebred Hanwoo steers. Sequence alignments observed 6 genetic variants located in exons 20, 24, 32, 34, and 39, and PCR-RFLP analysis confirmed these variations. Genotypes of the g.15532A>C locus were significantly associated with Linolenic acid (C18:3), and genotypes of the g.17924G>A locus were significantly associated with Palmitic (C16:0), Palmitoleic (C16:1), Oleic (C18:1), saturated fatty acids, and unsaturated fatty acids. The analysis revealed that SFA and UFA showed significant correlations with fatty acid composition (Myristic (C14:0), Palmitic (C16:0), Stearic (C18:0), Oleic (C18:1), and Eicosenoic (C20:1) acids). Oleic acid (C18:1) was negatively correlated with Myristic (C14:0), Palmitic (C16:0), and Palmitoleic (C16:1) acids (P<0.001).

Response surface optimization of ultrasonic-assisted extraction of carotenoids from oil palm (Elaeis guineensis Jacq.) fronds

Oil palm (Elaeis guineensis Jacq.) fronds (OPF) are the most abundant oil palm solid wastes that are generated during oil palm agriculture and harvest. Palm oil and some other palm wastes have been reported to contain high concentrations of carotenoids with vital bioactive properties. However, the extraction and quantification of carotenoids from OPF have not been reported. In this study, ultrasonic-assisted extraction, HPLC-FLD for quantification, and response surface methodology (RSM) for optimization of β-carotene, lutein, and zeaxanthin from OPF extracts were investigated. The effects of extraction temperature (X₁: 30-70°C), extraction time (X₂: 10-50 min), and solvent-sample ratio (X₃: 10-50 mL/g) on the recovery of β-carotene (Y₁), lutein (Y₂), and zeaxanthin (Y₃) were investigated using three-level Box-Behnken design (BBD) experiment. At a desirability of 1, the optimum extraction conditions for β-carotene (30.14°C, 37.11 min, and 23.18 mL/g), lutein (30.00°C, 39.09 min, and 19.24 mL/g), and zeaxanthin (30.09°C, 36.76 min, and 22.38 mL/g) yielded carotenoid concentrations of 17.95 μg/g dry weight (DW), 261.99 μg/g DW, and 29.99 μg/g DW, respectively.

Biological screening of 100 plant extracts for cosmetic use (I): inhibitory activities of tyrosinase and DOPA auto-oxidation

The aim of this study was to evaluate several plant extracts with a view to developing melanogenesis inhibitors. In this study, 100 plant extracts were screened to elucidate their whitening effects using in vitro inhibition of tyrosinase and DOPA auto-oxidation activity. Several plant extracts such as Chaenomeles speciosa, Dryopteris crassirhizoma, Gastrodia ellata, Glycyrrhiza glabra, Morus alba, Myristica fragrans, Rheum palmatum and Sophora japonica showed inhibition of mushroom tyrosinase activity. Plant extracts including Bupleurum falcatum, Caragana sinica, Morus alba and Tussilago farfara showed inhibition of DOPA auto-oxidation activity.

Reperfusion strategy for ST-segment elevation myocardial infarction: trend over a 10-year period

OBJECTIVES. To review the 10-year trend of reperfusion strategies in patients with ST-segment elevation myocardial infarction, and the adoption rate of percutaneous coronary interventions as opposed to thrombolytic therapy. Also to explore why some patients did not receive reperfusion therapy, and document changes in reperfusion strategies after the introduction of primary percutaneous coronary intervention programmes. DESIGN. Case series. SETTING. A regional hospital, Hong Kong. PATIENTS. All patients with ST-segment elevation myocardial infarction from January 2000 to December 2009. RESULTS. There were 1835 patients with ST-segment elevation myocardial infarction in that period, of which 1179 (64.3%) received reperfusion therapy (thrombolytic therapy, 46.0%; primary percutaneous coronary intervention, 17.5%; emergency coronary artery bypass graft, 0.7%). After introduction of the primary percutaneous coronary intervention programme, significantly more ST-segment elevation myocardial infarction cases underwent that particular intervention (1.6% in 2000 increasing to 30.6% in 2009), while the proportion receiving thrombolytic therapy declined (57.4% in 2000 decreasing to 35.0% in 2009). Seven reasons for no reperfusion therapy were identified. The commonest ones were delayed presentation (45.1%), succumbed before reperfusion (16.0%), multiple medical co-morbidities (15.2%), and contra-indication to thrombolytic therapy (14.8%). The proportion without reperfusion therapy due to a contra-indication to thrombolytic therapy declined (22.7% in 2000 decreasing to 4.9% to 2009), whilst an increasing proportion received primary percutaneous coronary interventions. CONCLUSIONS. Primary percutaneous coronary intervention is increasingly used as the reperfusion therapy in ST-segment elevation myocardial infarction and is replacing thrombolytic therapy, though the latter still remains a mainstay of therapy. A significant proportion of ST-segment elevation myocardial infarction cases received no reperfusion due to various reasons.

Effects of Hydrated Potato Starch on the Quality of Low-fat Ttoekgalbi (Korean Traditional Patty) Packaged in Modified Atmosphere Conditions during Storage

This study was carried out to investigate the effects of hydrated potato starch on the quality of low-fat ttoekgalbi (Korean traditional patty) packaged in modified atmosphere conditions during storage. The ttoekgalbi was prepared from 53.2% lean beef, 13.9% lean pork, 9.3% pork fat, and 23.6% other ingredients. Two low-fat ttoekgalbi treatments were prepared by substituting pork fat with hydrated potato starch; either by 50% fat replacement (50% FR) or 100% fat replacement (100% FR). Both 50% and 100% FR increased the moisture, crude protein, and decreased fat content, cooking loss, and hardness. For MAP studies, 200 g of ttoekgalbi were placed on the tray and filled with gas composed of 70% O₂: 30% CO₂ (70% O₂-MAP) and 30% CO₂: 70% N₂ (70% N₂-MAP), and were stored at 5°C for 12 d. During the storage time, both 50% and 100% FR showed higher protein deterioration, while no differences were found in CIE a*, CIE L*, lipid oxidation, and bacterial counts in comparison to control. The ttoekgalbi with 70% O₂-MAP was more red, lighter in color, and showed higher TBARS values compared with 70% N₂-MAP. The meat with 70% N₂-MAP showed lower aerobic bacterial counts in control than those with 70% O₂-MAP. The lower anaerobic bacterial counts were observed only in 50% FR and 100% FR packed with 70% N₂-MAP in comparison with 70% O₂-MAP. In conclusion, the fat replacement with hydrated potato starch showed no negative effects on the quality of low fat ttoekgalbi during storage and 70% N₂-MAP was better than 70% O₂-MAP for low-fat ttoekgalbi packaging.

Single nucleotide polymorphism association study for backfat and intramuscular fat content in the region between SW2098 and SW1881 on pig chromosome 6

This study was carried out to identify SNP associated with fatness traits on pig chromosome 6. In total, 11,067 putative genomic variations were detected in 125 complete bacterial artificial chromosome sequences corresponding to the region between SW2098 and SW1881, which harbors multiple QTL affecting intramuscular fat content (IMF) and backfat thickness (BFT). Among 173 putative SNP validated by MassArray, 120 SNP were used in an association study on 541 offspring produced by a cross of Korean native pig and Landrace breeds. The significance level of each SNP was determined using single marker regression analysis. Further, significant threshold values were determined using a false discovery rate. Nine out of 120 SNP showed significant effects on BFT or IMF or both. Of the 9 significant SNP, 4 were significantly associated with IMF, 7 were significantly related to BFT, and 2 SNP (Kps8172 and Kps6413) showed significant effects on both traits. Moreover, multiple regression analysis considering all significant SNP was used to correct spurious false positives due to linkage disequilibrium. Consequently, only 1 SNP (Kps6413) was significant for IMF, whereas 4 SNP including Kps6413 showed significant effects on BFT. The significant SNP had generally additive effects and on average explained 1.72% of the genetic variation for IMF and 3.92% for BFT, respectively. These markers can potentially be applied in pig breeding programs for improving IMF and BFT traits after validation in other populations.

Effects of p.C430S polymorphism in the PPARGC1A gene on muscle fibre type composition and meat quality in Yorkshire pigs

The peroxisome proliferator-activated receptor-gamma coactivator-1A (encoded by PPARGC1A) is involved in the formation of type I fibres. Therefore, the PPARGC1A gene can be considered as a functional candidate gene for muscle fibre type composition and meat quality in pigs. The aim of this study was to investigate the associations of the p.C430S polymorphic site in exon 8 of the PPARGC1A gene with muscle fibre characteristics and meat quality traits. The polymorphism was genotyped by PCR-RFLP using AluI restriction enzyme on a total of 152 Yorkshire pigs. Statistical analyses revealed that the p.C430S genotypes significantly affected number (P < 0.05) and area (P < 0.01) of type I muscle fibre, and were significantly associated with muscle pH (P < 0.001) and lightness(P < 0.01). On the basis of these results, we suggest that the p.C430S polymorphism can induce variation of type I fibre formation in porcine longissimus dorsi muscle and that it can be used as a meaningful molecular marker for better meat quality.

Angioplasty and stenting of atherosclerotic middle cerebral arteries with Wingspan: evaluation of clinical outcome, restenosis, and procedure outcome

BACKGROUND AND PURPOSE

MCA is a common location of intracranial stenosis. It is relatively more peripherally located and of a smaller caliber, and could therefore be a site technically more challenging and risky for angioplasty and stenting. The study aimed to evaluate the clinical outcome, restenosis rate, and procedural safety of Wingspan stent placement for atherosclerosis in the MCA compared with stenosis in other arteries.

MATERIALS AND METHODS

Patients who underwent Wingspan stent placement for symptomatic intracranial stenosis of ≥70% (or stenosis of ≥50% for recurrent ischemia despite medical therapy) were recruited prospectively and allocated into a study group (MCA stenosis, n=35) and a control group (other stenosis, n=25). Primary end points were the following: 1) all stroke or death rate at 1 year, and 2) significant in-stent restenosis rate at 1 year. Secondary end points were the following: 1) periprocedural complications within 24 hours, rate of TIA during the procedure, all stroke or death rate within 30 days; and 2) the inability to complete the procedure due to technical problems.

RESULTS

Results of study group versus the control group were the following: degree of stenosis, 78.4 ± 10.9% versus 72.5 ± 11.2% (P value=.0456); diameter of stenosis, 0.6 ± 0.3 versus 1.0 ± 0.5 mm (P=.0017); all stroke or death rate at 1 year, 14.3% versus 12% (OR=1.22); in-stent restenosis rate at 1 year, 10% versus 10.5% (OR=1.05); periprocedural complication rate at 24 hours, 2.9% versus 4% (OR=0.70); TIA rate during the procedure, 8.6% versus 4% (OR=2.25); all stroke or death rate at 30 days, 5.7% versus 12% (OR=0.44); and technical failure rate, 2.9% versus 0%.

CONCLUSIONS

In this study, there were no significant differences in procedural safety, patient outcome, and restenosis rates of stent placement between the group with MCA stenosis and the group with stenoses located at other sites.

Liver Surgery for Hepatocellular Carcinoma: Laparoscopic versus Open Approach

In this study, we try to compare the benefit of laparoscopic versus open operative procedures. Patients and Methods. One hundred and sixteen patients underwent laparoscopic liver resection (LR) and another 208 patients went for open liver resection (OR) for hepatocellular carcinoma (HCC). Patients' selection for open or laparoscopic approach was not randomized. Results. The CLIP score for LR and OR was 0.59 ± 0.75 and 0.86 ± 1.04, respectively, (P = .016). The operation time was 156.3 ± 308.2 and 190.9 ± 79.2 min for LR and OR groups, respectively. The necessity for blood transfusion was found in 8 patients (6.9%) and 106 patients (50.9%) for LR and OR groups. Patients resumed full diet on the 2nd and 3rd postoperative day, and the average length of hospital stay was 6 days and 12 days for LR and OR groups. The complication rate and mortality rate were 0% and 6.0%, 2.9% and 30.2% for LR and OR groups, respectively. The 1-yr, 3-yr, and 5-yr survival rate was 87.0%, 70.4%, 62.2% and 83.2%, 76.0%, 71.8% for LR and OR group, respectively, of non-significant difference. From these results, HCC patients accepted laparoscopic or open approach were of no significant differences between their survival rates.

Catalytic cracking of bio-oil to organic liquid product (OLP)

The main objective of this paper is to find the optimum operating condition to upgrade the EFB-derived pyrolysis oil (bio-oil) to liquid fuel, mainly gasoline using Taguchi Method. From the analysis that has been done, it is found that the optimum operating condition for heterogeneous catalytic cracking process is at 400 degrees C, 15min of reaction time using 30g of catalyst weight where operating at this condition produced the highest yield of gasoline fraction which is 91.67 wt.%. This observation proves that EFB-derived pyrolysis oil could be upgraded via heterogeneous catalytic cracking to produce gasoline.

Selection of best impregnated palm shell activated carbon (PSAC) for simultaneous removal of SO2 and NOx

This work examines the impregnated carbon-based sorbents for simultaneous removal of SO(2) and NOx from simulated flue gas. The carbon-based sorbents were prepared using palm shell activated carbon (PSAC) impregnated with several metal oxides (Ni, V, Fe and Ce). The removal of SO(2) and NOx from the simulated flue gas was investigated in a fixed-bed reactor. The results showed that PSAC impregnated with CeO(2) (PSAC-Ce) reported the highest sorption capacity among other impregnated metal oxides for the simultaneous removal of SO(2) and NOx. PSAC-Ce showed the longest breakthrough time of 165 and 115 min for SO(2) and NOx, respectively. The properties of the pure and impregnated PSAC were analyzed by BET, FTIR and XRF. The physical-chemical features of the PSAC-Ce sorbent indicated a catalytic activity in both the sorption of SO(2) and NOx. The formation of both sulfate (SO(4)(2-)) and nitrate (NO(3-)) species on spent PSAC-Ce further prove the catalytic role played by CeO(2).

Experience with hookwire localisation excision biopsy at a medical centre in Malaysia

INTRODUCTION

With an increasing number of women undergoing breast screening, an effective method of removing non-palpable lumps detected by mammography or sonography is by hookwire localisation excision biopsy (HWLB). The aim of this paper was to audit the practice of HWLB at the University Malaya Medical Centre.

METHODS

Patients with benign or suspicious preoperative diagnoses of a non-palpable lump and who underwent HWLB were included in this study. Pathological examination of the surgical specimens was conducted and a correlation with preoperative assessment modalities was reported.

RESULTS

A total of 59 HWLBs were carried out in 57 female patients. The mean age of the patients was 51.5 years. The overall malignancy rate was 32.3 percent (19 out of 59 cases) with a benign to malignant ratio of 3.1 to 1. Ten of these cases were ductal carcinoma-in-situ. Out of 25 patients who were suspicious on preoperative assessment, 16 malignancies were found, while in the 33 patients thought to be benign on preoperative assessment, there were three malignancies, giving a sensitivity of 84.2 percent and a specificity of 76.9 percent (p is less than 0.05). The mean tissue volume excised in 53 available records was 50.0 cm(3), with pathological tissue comprising only 15.4 percent of the total excised volume. Clear margins were obtained in 42.1 percent of the patients. The overall operative complication rate was 10.2 percent.

CONCLUSION

Malignancy was reported in one third of women undergoing HWLB, of which 16 had suspicious features on radiological assessment and/or fine needle aspiration cytology/core needle biopsy preoperatively. Non-palpable lumps should be excised by HWLB for a definitive diagnosis in case of any suspicion on preoperative assessment, as the prognosis is excellent.

Reporting 678 putative cSNPs from full-length enriched cDNA sequences of the Korean native pig

Sequences from the clones of full-length enriched cDNA libraries serve as valuable resources for functional genomic studies. We have analysed 1970 high-quality chromatograms (Phred value >or= 30) that were obtained from sequencing the 5' ends of brainstem, liver, neocortex and spleen clones derived from full-length enriched cDNA libraries from Korean native pigs. In addition, 50,000 pig expressed sequence tag (EST) sequence trace files were obtained from Genbank and combined with our sequencing information to facilitate SNP identification in silico. The process generated 8118 contigs, of which 239 included minimum one sequence from Korean native pig and contained 678 putative coding single nucleotide polymorphisms (cSNPs). Of these, 33 putative cSNPs were randomly selected for confirmatory analysis and validated using 20 pigs from four different breeds (Duroc, Landrace, Yorkshire, Korean native pig). Of the 33 putative cSNPs, 20 were confirmed (61%), which was similar to the frequency reported in other studies. We also identified 15 new cSNPs from the validation process, which were not detected by our in silico analysis. Our study shows that analysing genetically diverse pig breeds including the Korean native pig could serve as a useful strategy for generating a large number of cSNPs.

How do we interpret an elevated carbohydrate antigen 19-9 level in asymptomatic subjects?

AIM

This prospective cohort study aimed to evaluate the etiology of elevated CA 19-9 levels and to present appropriate guidelines for the asymptomatic patients.

METHODS

Between January 2004 and March 2007, we enrolled consecutive asymptomatic patients who had elevated CA 19-9 levels >37 U/mL. To evaluate the etiology, the CA 19-9 level was rechecked and further studies were carried out. If the CA 19-9 level decreased to the normal range, or if it showed a decreasing trend, then it was monitored annually. Yet, if the CA 19-9 level showed an increasing trend, then the level was monitored at intervals of 1, 3, and 6 months until no evidence of malignancy was proven.

RESULTS

Of the 62,976 patients, 501 (0.8%) subjects showed an elevated CA 19-9 level. This prospective analysis was conducted on 353 subjects (70.5%) who were followed up for at least 6 months. Ten patients (2.8%) were diagnosed with malignancies. There were 97 patients (27.5%) with benign diseases and 246 patients (69.7%) were deemed non-specific.

CONCLUSIONS

CA 19-9 should not be used as a screening tool. In the case of a persistently elevated CA 19-9 level, further work-up for determining the etiology should be done.

Optimization of microporous palm shell activated carbon production for flue gas desulphurization: experimental and statistical studies

Optimizing the production of microporous activated carbon from waste palm shell was done by applying experimental design methodology. The product, palm shell activated carbon was tested for removal of SO2 gas from flue gas. The activated carbon production was mathematically described as a function of parameters such as flow rate, activation time and activation temperature of carbonization. These parameters were modeled using response surface methodology. The experiments were carried out as a central composite design consisting of 32 experiments. Quadratic models were developed for surface area, total pore volume, and microporosity in term of micropore fraction. The models were used to obtain the optimum process condition for the production of microporous palm shell activated carbon useful for SO2 removal. The optimized palm shell activated carbon with surface area of 973 m(2)/g, total pore volume of 0.78 cc/g and micropore fraction of 70.5% showed an excellent agreement with the amount predicted by the statistical analysis. Palm shell activated carbon with higher surface area and microporosity fraction showed good adsorption affinity for SO2 removal.

Effects of cyclosporine on the production of the reactive oxygen species in the glial cells

OBJECTIVES

After organ transplantation, some patients suffer mild neurological symptoms such as tremor to severe complications including seizures and encephalopathy. Among the immunosuppressants, cyclosporine (CsA) can induce neurological side effects. However, the mechanisms of encephalopathy by CsA are not fully understood. We measured the production of reactive oxygen species (ROS) in the glioma cells after CsA treatment.

METHODS

CsA (2.5 mmol/L) added to glioma cells was incubated for 60 minutes at 37 degrees C. ROS production was evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2',7'-dichlorofluorescin using VICTOR3 multilabel counter.

RESULTS

CsA resulted in ROS production by glioma cells. The ROS production increased with the time of exposure to CsA.

CONCLUSIONS

These findings indicated that CsA may contribute to neurological side effects via ROS production.

Association of carotid hemodynamics with risk of coronary heart disease in a Taiwanese population with essential hypertension

BACKGROUND

The resistive index (RI) of the carotid artery is a hemodynamic parameter that depends on the degree of vascular resistance in hypertensive patients. The pulsatility index (PI) of the carotid artery was shown to be associated with microangiopathy in diabetic patients. In contrast to carotid intima-media thickness (IMT), no study has yet applied the carotid RI and PI to estimate coronary heart disease (CHD) risk.

METHODS

Framingham risk scores (FRS) were determined for 62 patients (32 women; mean age 65 years (range 35-83)) with essential hypertension. Duplex sonography of the common carotid artery (CCA) was performed, with determination of RI, PI, and IMT.

RESULTS

The mean FRS of all patients was 14.3% (range 1-30%), the mean IMT value of CCA was 0.89 +/- 0.23 mm, the mean RI was 0.71 +/- 0.07, and the mean PI was 1.46 +/- 0.39. FRS was found to have highly significant correlations with RI and PI (r = 0.47, P < 0.001 and r = 0.45, P < 0.001, respectively). The correlation between FRS and IMT was also significant (r = 0.41, P = 0.001). Multiple stepwise regression analysis showed that RI was an independent determinant of the risk of CHD.

CONCLUSIONS

Although RI indirectly reflected the atherosclerotic process, the correlation between RI and CHD risk was comparable to the well-known correlation between cardiovascular event and carotid IMT. Hence, carotid RI can be used as a tool for risk stratification in Taiwanese patients with essential hypertension.

Genetic structure of pig breeds from Korea and China using microsatellite loci analysis

To understand molecular genetic characteristics of Korean pigs, the genetic relationships of nine pig breeds including two Korean pigs (Korean native pig and Korean wild pig), three Chinese pigs (Min pig, Xiang pig, and Wuzhishan pig), and four European breeds (Berkshire, Duroc, Landrace, and Yorkshire) were characterized from a 16-microsatellite loci analysis. The mean heterozygosity within breeds ranged from 0.494 to 0.703. Across multiple loci, significant deviation from Hardy-Weinberg equilibrium was observed in most pig breeds, except for two Chinese pigs (Min pig and Wuzhishan pig). This deviation was in the direction of heterozygote deficit. Across population loci, 36 of 144 significantly deviated (P < 0.05) from Hardy-Weinberg equilibrium. The mean FST, a measure of genetic divergence among subpopulations, of all loci indicated that 26.1% of total variation could be attributed to the breed difference. Relationship trees based on the Nei's DA genetic distance and scatter diagram from principal component analysis consistently displayed pronounced genetic differentiation among the Korean wild pig, Xiang pig, and Wuzhishan pig. Individual assignment test using a Bayesian method showed 100% success in assigning Korean and Chinese individual pigs into their correct breeds of origin and 100% exclusion success from all alternative reference populations at P < 0.001. These findings indicate that the Korean native pig has been experiencing progressive interbreeding with Western pig breeds after originating from a North China pig breed with a black coat color. Considering the close genetic relationship of Korean pigs to the Western breeds such as Berkshire and Landrace, our findings can be used as valuable genetic information for the preservation and further genetic improvement of the Korean native pig.

Isolation and characterization of the bovine microsatellite loci

Microsatellite loci were isolated using five repetitive probes for Korean native cattle. Eleven microsatellite loci were developed based on a biotin hybrid capture method, and enrichment of the genomic libraries (AAAT, TG, AG, T, and TGC repeats) was performed using Sau3AI adapters. The isolated markers were tested in two half-sib Korean cattle families and four imported breeds (Angus, Limousine, Holstein, and Shorthorn). Nine informative microsatellite loci were observed, and two microsatellite loci were revealed as monomorphic in Korean cattle. In the imported breeds, however, all of the markers were informative. In total, 213 alleles were obtained at the 11 loci across five breeds, and the average number of alleles found per locus, considering all populations, was 4.26. Heterozygosity was 0.71 (expected) and 0.57 (observed). The range of the polymorphic information content for the markers in all cattle populations was 0.43-0.69. Eleven percent of genetic variation was attributed to differentiation between populations as determined by the mean F (ST) values. The remaining 89% corresponded to differences among individuals. The isolated markers may be used to identify and classify the local breeds on a molecular basis.

Polyoma virus-associated nephropathy and concurrent cytomegalovirus infection in the kidney transplant recipients

INTRODUCTION

Cytomegalovirus (CMV) and polyoma virus BK (BKV) may both establish latency following primary infection. Frequent reactivation of these viruses can occur in the kidney transplant recipients. BKV may induce CMV gene expression by stimulating cellular regulator proteins or by its own gene regulator proteins. A high rate of concurrent CMV infections has been noted in kidney transplant recipients with polyoma virus-associated nephropathy (PVAN).

METHODS

PVAN was identified in 10 of 191 patients who received kidney transplants between October 1998 and September 2003. PVAN was confirmed by allograft kidney biopsy. Four of the 10 patients were complicated by concurrent CMV infection.

RESULTS

Two patients had only serological evidence of CMV infection and one patient had CMV gastritis. These three patients were treated with intravenous ganciclovir with good results. Disseminated ganciclovir-resistant CMV disease was demonstrated in the remaining patient. This 34-year-old kidney transplant recipient with PVAN died of multiorgan failure despite antiviral therapy with both ganciclovir and foscarnet.

CONCLUSION

PVAN with concurrent CMV infection in kidney transplant recipients showed variable clinical courses including mortality. Further studies are needed to elucidate the influence of PVAN on the pathogenesis of CMV infection.

Intraductal papillary mucinous tumour of the pancreas: differentiation of malignancy and benignancy by CT

AIM

To retrospectively identify signs predictive of malignant intraductal papillary mucinous tumour (IPMT) of the pancreas on computed tomography (CT) images.

MATERIALS AND METHODS

Thirty-four benign and 21 malignant pancreatic IPMTs were evaluated. Preoperative helical CT images in these 55 cases of pathologically proven pancreatic IPMT were reviewed by two radiologists unaware of the histological grading. Tumour morphological types, locations, numbers and sizes of cystic lesions, maximum main pancreatic duct diameters, the presence of septa, mural nodule, wall thickening, and calcification in cysts, communication with the main pancreatic duct, peripancreatic haziness, protrusion of duodenal papilla, pancreatic atrophy, lymphadenopathy and distant metastasis were analysed using univariate and multivariate analysis.

RESULTS

Main duct IPMTs were more likely to be malignant (71%) than branch duct (23%) or combined type IPMTs (28%; p=0.002). Among the branch duct type and combined types, large cystic lesion (p=0.018), the presence of a mural nodule (p=0.018), a thickened wall (p=0.009), and peripancreatic haziness (p=0.039) were found to predict malignancy.

CONCLUSION

CT is helpful in the preoperative differentiation of malignant and benign pancreatic IPMT. The presence of a dilated main pancreatic duct, mural nodules, thickened wall and peripancreatic haziness may be used as independent predictive signs of malignancy.

Hyperleptinaemia and hypoadiponectinaemia are associated with gallstone disease

BACKGROUND

Gallstone disease has been regarded as an obesity-related disease. Therefore, we hypothesized that leptin and adiponectin, mainly produced by adipose tissue, may play roles in gallstone disease.

PATIENTS AND METHODS

The RIA method was used to analyze serum leptin and adiponectin levels of 90 gallstone patients and 91 healthy subjects.

RESULTS

Our results showed that BMI, fasting glucose, serum AST and ALT, and leptin were significantly increased in the gallstone patients as compared with the healthy subjects (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P = 0.013, respectively). Intriguingly, serum adiponectin was the only variable to be significantly decreased in the gallstone patients (P = 0.002). Furthermore, serum AST, leptin, and adiponectin were significantly associated with gallstone disease (P < 0.001, P = 0.021, and P = 0.006, respectively). Overweight (BMI >or= 25 kg m(-2)), but not normal-weight, gallstone patients had an increased serum leptin and a decreased serum adiponectin level as compared with matched healthy subjects (P < 0.001 and P = 0.024, respectively). In addition, serum leptin was positively correlated with BMI and serum cholesterol, while serum adiponectin was inversely correlated with serum triglyceride in the gallstone patients.

CONCLUSIONS

Our study indicated that hyperleptinaemia and hypoadiponectinaemia might be involved in the occurrence of gallstone disease. However, the causal relationship of hyperleptinaemia and hypoadiponectinaemia with gallstone disease might require further investigation.

Optimizing the specific surface area of fly ash-based sorbents for flue gas desulfurization

High performance sorbents for flue gas desulfurization can be synthesized by hydration of coal fly ash, calcium sulfate, and calcium oxide. In general, higher desulfurization activity correlates with higher sorbent surface area. Consequently, a major aim in sorbent synthesis is to maximize the sorbent surface area by optimizing the hydration conditions. This work presents an integrated modeling and optimization approach to sorbent synthesis based on statistical experimental design and two artificial intelligence techniques: neural network and genetic algorithm. In the first step of the approach, the main and interactive effects of three hydration variables on sorbent surface area were evaluated using a full factorial design. The hydration variables of interest to this study were hydration time, amount of coal fly ash, and amount of calcium sulfate and the levels investigated were 4-32 h, 5-15 g, and 0-12 g, respectively. In the second step, a neural network was used to model the relationship between the three hydration variables and the sorbent surface area. A genetic algorithm was used in the last step to optimize the input space of the resulting neural network model. According to this integrated modeling and optimization approach, an optimum sorbent surface area of 62.2m(2)g(-1) could be obtained by mixing 13.1g of coal fly ash and 5.5 g of calcium sulfate in a hydration process containing 100ml of water and 5 g of calcium oxide for a fixed hydration time of 10 h.

Neural network modeling of the kinetics of SO2 removal by fly ash-based sorbent

The mechanistic modeling of the sulfation reaction between fly ash-based sorbent and SO2 is a challenging task due to a variety reasons including the complexity of the reaction itself and the inability to measure some of the key parameters of the reaction. In this work, the possibility of modeling the sulfation reaction kinetics using a purely data-driven neural network was investigated. Experiments on SO2 removal by a sorbent prepared from coal fly ash/CaO/CaSO4 were conducted using a fixed bed reactor to generate a database to train and validate the neural network model. Extensive SO2 removal data points were obtained by varying three process variables, namely, SO2 inlet concentration (500-2000 mg/L), reaction temperature (60-80 degreesC), and relative humidity (50-70%), as a function of reaction time (0-60 min). Modeling results show that the neural network can provide excellent fits to the SO2 removal data after considerable training and can be successfully used to predict the extent of SO2 removal as a function of time even when the process variables are outside the training domain. From a modeling standpoint, the suitably trained and validated neural network with excellent interpolation and extrapolation properties could have immediate practical benefits in the absence of a theoretical model.

Semi-constrained total elbow arthroplasty for the treatment of rheumatoid arthritis of the elbow

INTRODUCTION

We retrospectively reviewed the results of total elbow arthroplasty in patients with rheumatoid arthritis of the elbow followed for a minimum of two years.

METHODS

Between September 1999 and March 2001, seven patients with rheumatoid arthritis of the elbow were treated with total elbow arthroplasty using the semi-constrained Coonrad-Morrey elbow replacement prostheses. One patient died 19 months after her surgery and was excluded from the study. Two patients had bilateral total elbow replacements. Eight elbows were thus available for review. The mean age of our patients at the time of surgery was 55.5 years. The indication for surgery was severe pain and stiffness in six elbows, and distal humerus fractures in two elbows.

RESULTS

The mean duration of postoperative hospitalisation stay was 6.6 days. The average length of follow-up was 39.4 months. Six elbows had no pain, while two elbows had mild pain. The mean arc of flexion was 101.3 degrees. The mean Mayo elbow performance score was 93.1 points. Excellent results were achieved in six elbows, while two elbows had good outcome. There was one case of intraoperative lateral condylar fracture treated with internal fixation. One patient developed blisters postoperatively but resolved with dressings and antibiotics.

CONCLUSION

Our small study revealed good to excellent short-term outcome with the use of semi-constrained total elbow arthroplasty for the treatment of rheumatoid arthritis of the elbow in Asian patients.