Associated genetic polymorphisms and clinical manifestations in systemic lupus erythematosus in Asian populations - A systematic literature review.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a chronic and life-threatening autoimmune disease. Its prevalence and clinical manifestations are known to be particularly severe in the Asian populations. Although genetics is known to play an important role in SLE susceptibility and clinical manifestations, the specific polymorphisms associated with these phenotypes in Asia are unclear. Therefore, we aim to review the association of SLE genetic polymorphisms with lupus manifestations across Asian populations and their role in the pathogenesis of SLE. METHODS: A systematic search was conducted on PubMed, EBSCOHost, and Web of Science. We identified 22 casecontrol studies that matched our inclusion and exclusion criteria. Information such as study characteristics, genetic polymorphisms associated with SLE, and organ manifestations was extracted and reported in this review. RESULTS: In total, 30 polymorphisms in 16 genes were found to be associated with SLE among Asians. All included polymorphisms also reported associations with various SLE clinical features. The association of rs1234315 in TNFSF4 linking to SLE susceptibility (P=4.17x10-17 OR=1.45 95% CI=1.34-1.59) and musculoskeletal manifestation (P=3.35x10-9, OR=1.37, 95%CI= 1.23-1.51) might be the most potential biomarkers to differentiate SLE between Asian and other populations. In fact, these associated genetic variants were found in loci that were implicated in immune systems, signal transduction, gene expression that play important roles in SLE pathogenesis. DISCUSSIONS AND CONCLUSIONS: This review summarized the potential correlation between 30 genetic polymorphisms associated with SLE and its clinical manifestations among Asians. More efforts in dissecting the functional implications and linkage disequilibrium of associated variants may be required to validate these findings.

Cost-effectiveness analysis of pembrolizumab compared to standard of care as first line treatment for patients with advanced melanoma in Hong Kong.

BACKGROUND: Pembrolizumab has been shown to improve overall survival (OS) and progression free survival (PFS) compared to ipilimumab in patients with ipilimumab-naïve advanced melanoma; however, there are no published data on the cost-effectiveness for pembrolizumab compared to standard-of-care treatments currently used in Hong Kong for advanced melanoma. METHODS: A partitioned-survival model based on data from a recent randomized phase 3 study (KEYNOTE-006) and meta-analysis was used to derive time in PFS, OS, and post-progression survival for pembrolizumab and chemotherapy, such as dacarbazine (DTIC), temozolomide (TMZ), and the paclitaxel-carboplatin combination (PC). A combination of clinical trial data, published data, results of meta-analysis, and melanoma registry data was used to extrapolate PFS and OS curves. The base-case time horizon for the model was 30 years with costs and health outcomes discounted at a rate of 5% per year. Individual patient level data on utilities and frequencies of adverse events were obtained from the final analysis of KEYNOTE-006 (cut-off date: 3-Dec-15) for pembrolizumab. Cost data included drug acquisition, treatment administration, adverse event management, and clinical management of advanced melanoma. The distribution of patient weight from the Hong Kong population was applied to calculate the drug costs. Analyses were performed from a payer's perspective. The incremental cost effectiveness ratio (ICER) expressed as cost in US Dollars (USD) per quality-adjusted life years (QALYs) was the main outcome. RESULTS: In base-case scenario, the ICER for pembrolizumab as a first-line treatment for advanced melanoma was USD49,232 compared to DTIC, with the ICER values lower than cost-effectiveness threshold in Hong Kong. Results comparing pembrolizumab to TMZ and to PC were similar to that when compared to DTIC. Probability sensitivity analyses showed that 99% of the simulated ICERs were below three times the Gross Domestic Product (GDP) per capita for Hong Kong (currently at $119,274//QALY threshold). In a scenario analysis comparing pembrolizumab with ipilimumab, the estimated ICER was USD8,904. CONCLUSIONS: Pembrolizumab is cost-effective relative to chemotherapy (DTIC, TMZ and PC), and highly-cost-effective compared to ipilimumab, for the first-line treatment of advanced melanoma in Hong Kong.

Impact of ledipasvir/sofosbuvir on the work productivity of genotype 1 chronic hepatitis C patients in Asia.

Chronic, untreated hepatitis C virus (HCV) infection is associated with a poor clinical prognosis and a detrimental impact on patients' lives, including on work productivity. To estimate the value of productivity losses due to genotype 1 (GT1) HCV infection in Hong Kong, Singapore, South Korea and Taiwan and to estimate the potential productivity gains associated with treating patients with ledipasvir/sofosbuvir (LDV/SOF) therapy, an economic model was developed with a time horizon of 1 year. Hepatitis C virus patients entered the model at 12 weeks post-treatment, having achieved or not achieved sustained virological response (SVR). Absenteeism and presenteeism rates were taken from a pooled analysis of data from the ION 1-3 studies. These rates were converted into hours of lost productivity, multiplied by the average wage and applied to the total employed, adult GT1 population in each country. Results were compared assuming no treatment, and assuming all patients were treated with LDV/SOF. Total productivity losses due to untreated HCV were: $11.3 million, $17.1 m, $146.0 m and $349.1 m in Hong Kong, Singapore, South Korea and Taiwan. LDV/SOF treatment resulted in economic gains of $4.5 m, $6.8 m, $58.7 m and $138 m, respectively. These gains were due to reduced presenteeism. The results were sensitive to changes in the prevalence of HCV and the average wage. In conclusion, productivity losses due to untreated HCV infection represent a substantial economic burden. By instituting universal HCV treatment with LDV/SOF (or other therapies with high SVR rates), productivity gains can be achieved.

An analysis of genetic association in opioid dependence susceptibility.

WHAT IS KNOWN: Drug addiction is a novelty-seeking personality trait that is associated with the candidate genes OPRD1 (opioid delta receptors), OPRK1 (opioid kappa receptors) and PDYN (prodynorphin). However, associations between single nucleotide polymorphisms (SNPs) rs1042114 (80G>T) of the OPRD1 gene, rs702764 (843 A>G) of the OPRK1 gene, and rs910080 (3' UTR _743T>C), rs1997794 (5' UTR -381A>G) and rs1022563 (3' UTR) of the PDYN gene and novelty seeking remain controversial as reported results have not been reproducible. OBJECTIVE: The goal of this study was to determine the frequencies of SNPs rs1042114, rs702764, rs1997794, rs1022563 and rs910080 in the Malaysian population and to study their association with opioid dependence in Malaysian Malays. METHODS: A total of 459 Malay male with opioid dependence and 543 healthy male (controls) subjects were included in this study. SNPs were genotyped using the TaqMan SNP genotyping assay. Statistical analysis was performed using Golden Helix SVS software suite to identify the distribution of allele and genotype frequencies, and SNP-SNP interactions were also analysed in this study. RESULTS AND DISCUSSION: SNP rs1042114 in the OPRD1 gene is strongly associated with opiate addiction (P=.0001). In individuals homozygous for this risk allele, the likelihood of opiate addiction is increased by a factor 1.62 (95% confidence interval (CI) 1.412-1.875). Polymorphic alleles at SNP rs702764 of OPRK1 were not associated with opioid dependence. A significant association between opioid dependence and SNP rs910080 of PDYN (P=.0217) was detected, but there was no association for SNPs rs199774 and rs1022563. A significant interaction was also identified between homozygous wild-type genotype TT of rs702764 with the risk genotypes TG/GG of rs1042114 (odds ratio (OR)=2.111 (95% CI 1.227-3.631), P=.0069) and with the risk genotypes GA/AA of rs910080 (OR=1.415 (95% CI 1.04-1.912), P=.0239). WHAT IS NEW AND CONCLUSION: The results indicate that SNPs rs1042114 and rs910080 contribute to vulnerability to opioid dependence in the Malaysian Malay population. These results will help us to understand the effect of the SNPs and the SNP-SNP interaction on opioid dependence and may assist in efforts to screen vulnerable individuals and match them with individually tailored prevention and treatment strategies.

Hydrothermally-grown ZnO nanowire tips for scanning tunnelling microscopy.

The probe tip is pivotal in determining the resolution and nature of features observed in the Scanning Tunnelling Microscope (STM). We have augmented a conventional Pt/Ir metallic tip with a hydrothermally grown ZnO nanowire (NW). Atomic resolution imaging of graphite is attained. Current-voltage (IV) characteristics demonstrate an asymmetry stemming from the unintentional n-type doping of the ZnO NW, whereas the expected Schottky barrier at the ZnO-Pt/Ir interface is shown to have negligible effect. Moreover the photoconductivity of the system is investigated, paving the way towards a photodetector capable of atomic resolution.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method development for screening of potential tamoxifen-drug/herb interaction via in vitro cytochrome P450 inhibition assay.

Screening for potential drug-drug interaction (DDI) or herb-drug interaction (HDI) using in vitro cytochrome P450 inhibition (IVCI) assays requires robust analytical methods with high sensitivity and reproducibility. Utilization of liquid chromatography-mass spectrometry (LC-MS) for analyte quantification is often hampered by the presence of non-volatile IVCI sample buffer constituents that often results in ion suppression. In this study, to enable screening of drug interactions involving tamoxifen (TAM) metabolism using IVCI-LC-MS/MS, a liquid-liquid extraction (LLE) method was developed and optimized for sample clean-up. Utilization of chloroform as extraction solvent and adjustment of sample pH to 11 was found to result in satisfactory recovery (>70%) and low ion suppression (<19%). A LC-MS/MS method was subsequently developed and validated for simultaneous quantification of major TAM metabolites, such as N-desmethyltamoxifen (NDT), endoxifen (EDF) and 4-hydroxytamoxifen (HTF) to enable IVCI sample analysis. Satisfactory separation of E-/Z-isomers of endoxifen with peak resolution (Rs) of 1.9 was achieved. Accuracy and precision of the method was verified within the linear range of 0-50 ng/mL for NDT, 0-25 ng/mL for HTF and 0-25 ng/mL for EDF (E/Z isomers). Inhibitory potency (IC50, Ki and mode of inhibition) of known CYP inhibitors and Strobilanthes crispus extract was then evaluated using the validated method. In summary, the results demonstrated applicability of the developed LLE and validated LC-MS/MS method for in vitro screening of DDI and HDI involving TAM metabolism.

Ranibizumab and pegaptanib for the treatment of age-related macular degeneration: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of ranibizumab and pegaptanib for subfoveal choroidal neovascularisation (CNV) associated with wet age-related macular degeneration (AMD). DATA SOURCES: Electronic databases were searched from inception to September 2006. Experts in the field were consulted and manufacturers' submissions were examined. REVIEW METHODS: The quality of included studies was assessed using standard methods and the clinical effectiveness data were synthesised through a narrative review with full tabulation of results. A model was developed to estimate the cost-effectiveness of ranibizumab and of pegaptanib (separately), compared with current practice or best supportive care, from the perspective of the NHS and Personal Social Services. Two time horizons were adopted for each model. The first adopted time horizons determined by the available trial data. The second analysis extrapolated effects of treatment beyond the clinical trials, adopting a time horizon of 10 years. RESULTS: The combined analysis of two randomised controlled trials (RCTs) of pegaptanib [0.3 mg (licensed dose), 1.0 mg and 3.0 mg] versus sham injection in patients with all lesion types was reported by three publications (the VISION study). Three published RCTs of ranibizumab were identified (MARINA, ANCHOR, FOCUS), and an additional unpublished RCT was provided by the manufacturer (PIER). Significantly more patients lost less than 15 letters of visual acuity at 12 months when taking pegaptanib (0.3 mg: 70% of patients; 1.0 mg: 71% of patients; 3.0 mg: 65% of patients) or ranibizumab (0.3 mg: 94.3-94.5%; 0.5 mg: 94.6-96.4%) than sham injection patients (55% versus pegaptanib and 62.2% versus ranibizumab) or, in the case of ranibizumab, photodynamic therapy (PDT) (64.3%). The proportion of patients gaining 15 letters or more (a clinically important outcome having a significant impact on quality of life) was statistically significantly greater in the pegaptanib group for doses of 0.3 and 1.0 mg but not for 3.0 mg, and for all ranibizumab groups compared to the sham injection groups or PDT. This was also statistically significant for patients receiving 0.5 mg ranibizumab plus PDT compared with PDT plus sham injection. Pegaptanib patients lost statistically significantly fewer letters after 12 months of treatment than the sham group [mean letters lost: 7.5 (0.3 mg), 6.5 (1.0 mg) or 10 (3.0 mg) vs 14.5 (sham)]. In the MARINA and ANCHOR trials, ranibizumab patients gained letters of visual acuity at 12 months whereas patients with sham injection or PDT lost about 10 letters (p<0.001) and in the PIER study, ranibizumab patients lost significantly fewer than the sham injection group. Significantly fewer patients receiving pegaptanib or ranibizumab deteriorated to legal blindness compared with the control groups. Adverse events were common for both pegaptanib andranibizumab but most were mild to moderate. Drug costs for 1 year of treatment were estimated as 4626 pounds for pegaptanib and 9134 pounds for ranibizumab. Non-drug costs accounted for an additional 2614 pounds for pegaptanib and 3120 pounds for ranibizumab. Further costs are associated with the management of injection-related adverse events, from 1200 pounds to 2100 pounds. For pegaptanib compared with usual care, the incremental cost-effectiveness ratio (ICER) ranged from 163,603 pounds for the 2-year model to 30,986 pounds for the 10-year model. Similarly, the ICERs for ranibizumab for patients with minimally classic and occult no classic lesions, compared with usual care, ranged from 152,464 pounds for the 2-year model to 25,098 pounds for the 10-year model. CONCLUSIONS: Patients with AMD of any lesion type benefit from treatment with pegaptanib or ranibizumab on measures of visual acuity when compared with sham injection and/or PDT. Patients who continued treatment with either drug appeared to maintain benefits after 2 years of follow-up. When comparing pegaptanib and ranibizumab, the evidence was less clear due to the lack of direct comparison through head-to-head trials and the lack of opportunity for indirect statistical comparison due to heterogeneity. The cost-effectiveness analysis showed that the two drugs offered additional benefit over the comparators of usual care and PDT but at increased cost. Future research should encompass trials to compare pegaptanib with ranibizumab and bevacizumab, and to investigate the role of verteporfin PDT in combination with these drugs. Studies are also needed to assess adverse events outside the proposed RCTs, to consider the optimal dosing regimes of these drugs and the benefits of re-treatment after initial treatment, and to review costing in more detail. Health state utilities and their relationship with visual acuity and contrast sensitivity, the relationship between duration of vision loss and the quality of life and functional impact of vision loss, behavioural studies of those genetically at risk are other topics requiring further research.

The clinical effectiveness and cost-effectiveness of gemcitabine for metastatic breast cancer: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of gemcitabine, used in combination with paclitaxel, as a second-line treatment for people with metastatic breast cancer who have relapsed following treatment with anthracycline-based chemotherapy. DATA SOURCES: Electronic databases were searched from inception to March 2006. Clinical advisers were also consulted. REVIEW METHODS: A systematic review of the literature was undertaken to appraise the clinical and cost-effectiveness of gemcitabine. A Markov state transition model was developed for the economic evaluation. RESULTS: The systematic review identified only one randomised controlled trials (RCT), and this has not yet been fully published. The methodological quality and quality of reporting of the included trial were assessed to be poor using standard criteria, but this may be due to the lack of information in the limited publications rather than being a fair reflection of the trial's quality. This RCT compared gemcitabine and paclitaxel therapy with paclitaxel monotherapy in 529 patients with metastatic breast cancer who had previously received anthracyclines, but no prior chemotherapy for metastatic breast cancer. Approximately 71% of the gemcitabine/paclitaxel patients survived for 1 year, compared with 61% of the paclitaxel group. The hazard ratio showed a 26% lower chance of survival in the paclitaxel group, and time to progressive disease was also shorter in this group. The overall response rate was higher in the gemcitabine/paclitaxel group than in the paclitaxel group. Adverse events, particularly neutropenia, were more common with gemcitabine/paclitaxel combination therapy than with paclitaxel therapy alone. The economic model was run for a simulation of 1000 patients, assuming that chemotherapy continued until patients' disease progressed. This base-case analysis found an incremental cost-effectiveness ratio (ICER) of 58,876 pounds per quality-adjusted life-year (QALY) gained and 30,117 pounds per life-year gained. The model was re-run with treatment restricted to a maximum of six cycles per patient, reflecting normal practice. This yielded an ICER of 38,699 pounds per QALY gained and 20,021 pounds per life-year gained. CONCLUSIONS: The review of clinical effectiveness is based on data from a single RCT that has not yet been fully published. While only tentative conclusions can be drawn from this, the evidence may indicate that treatment with gemcitabine and paclitaxel confers an improved outcome for patients in terms of survival and disease progression, but at the cost of increased toxicity. An economic model developed for this review reflects high costs per QALY for this treatment combination. The base-case analysis shows high ICERs, with costs per QALY gained close to 60,000 pounds. Adopting a more realistic treatment protocol, with chemotherapy limited to a maximum of six cycles, gives a more favourable cost-effectiveness estimate. However, this was still higher than would usually be considered to be a cost-effective treatment from the NHS's perspective. Future research recommendations include an update of this review in 12-18 months' time, by which time the included RCT should be fully published. It would also be useful to compare gemcitabine with currently used treatments for metastatic breast cancer, including capecitabine and vinorelbine.

The "U-ligament" for collateral ligament reconstruction in duplicate thumb.

Duplicate thumb is a common congenital difference with complex management. Surgical treatment includes reconstruction of the collateral ligaments to optimise future function and cosmesis. We present the use of the "U-ligament" to further refine collateral ligament reconstruction. We have found it to be a simple and reliable technique.

Taperosis: Does head length affect fretting and corrosion in total hip arthroplasty?

Tribocorrosion at the head-neck taper interface - so-called 'taperosis' - may be a source of metal ions and particulate debris in metal-on-polyethylene total hip arthroplasty (THA). We examined the effect of femoral head length on fretting and corrosion in retrieved head-neck tapers in vivo for a minimum of two years (mean 8.7 years; 2.6 to 15.9). A total of 56 femoral heads ranging from 28 mm to 3 mm to 28 mm + 8 mm, and 17 femoral stems featuring a single taper design were included in the study. Fretting and corrosion were scored in three horizontally oriented concentric zones of each taper by stereomicroscopy. Head length was observed to affect fretting (p = 0.03), with 28 mm + 8 mm femoral heads showing greater total fretting scores than all other head lengths. The central zone of the femoral head bore taper was subject to increased fretting damage (p = 0.01), regardless of head length or stem offset. High-offset femoral stems were associated with greater total fretting of the bore taper (p = 0.04). Increased fretting damage is seen with longer head lengths and high-offset femoral stems, and occurs within a central concentric zone of the femoral head bore taper. Further investigation is required to determine the effect of increased head size, and variations in head-neck taper design.

Drug chirality and its clinical significance.

Approximately 1 in 4 therapeutic agents are marked as racemic mixtures, the individual enantiomers of which frequently differ in both their pharmacodynamic and pharmacokinetic profiles. The use of racemates has become the subject of considerable discussion in recent years, and an area of concern for both the pharmaceutical industry and regulatory authorities. The use of single enantiomers has a number of potential clinical advantages, including an improved therapeutic/pharmacological profile, a reduction in complex drug interactions, and simplified pharmacokinetics. In a number of instances stereochemical considerations have contributed to an understanding of the observed pharmacological effects of a drug administered as a racemate. However, relatively little is known of the influence of patient factors (e.g. disease state, age, gender and genetics) on drug enantiomer disposition and action in man. Examples may also be cited where the use of a single enantiomers, nonracemic mixtures and racemates of currently used agents may offer clinical advantages. The issues associated with drug chirality are complex and depend upon the relative merits of the individual agent. In the future it is likely that a number of existing racemates will be re-marketed as single enantiomer products with potentially improved clinical profiles and possible novel therapeutic indications.

Selective extraction of salbutamol from human plasma with the use of phenylboronic acid.

An investigation was conducted on the usage of a single-step extraction procedure involving the retention of a phenylboronate-salbutamol complex on an end-capped C18 solid-phase sorbent to determine the level of salbutamol in human plasma samples. Propranolol, a beta-blocker, was chosen as the internal standard for this assay. In this solid-phase clean-up method, 50 mM sodium carbonate buffer, pH 9.60, was used for conditioning the column as well as washing the endogenous interference. Under the optimal conditions, the recovery of salbutamol from spiked plasma samples was found to be high and reproducible with mean recoveries (n = 3) of more than 90% after elution by using 50% 1 M trifluoroacetic acid in methanol. This sample clean-up step was effectively analyzed under reversed-phase high-performance liquid chromatography with fluorimetric detection. The method was successfully applied to the routine measurement of salbutamol in human plasma from the bioequivalence study on the different administration route of salbutamol. Quantification of salbutamol was convincingly reported with the correlation of coefficient of 0.9980 for the concentration range from 0 to 1000 ng ml(-1). An adequate precision was achieved with both between- and within-day precisions of less than 10% (n = 6) for 100 and 1000 ng ml(-1) and less than 15% (n = 6) for 10 ng ml(-1).

Concurrent production of chitin from shrimp shells and fungi.

Crustacean shells constitute the traditional and current commercial source of chitin. Conversely, the control of fungal fermentation processes to produce quality chitin makes fungal mycelia an attractive alternative source. Therefore, the exploitation of both of these sources to produce chitin in a concurrent process should be advantageous and is reported here. Three proteolytic Aspergillus niger (strains 0576, 0307 and 0474) were selected from a screening for protease activity from among 34 zygomycete and deuteromycete strains. When fungi and shrimp shell powder were combined in a single reactor, the release of protease by the fungi facilitated the deproteinization of shrimp-shell powder and the release of hydrolyzed proteins. The hydrolyzed proteins in turn were utilized as a nitrogen source for fungal growth, leading to a lowering of the pH of the fermentation medium, thereby further enhancing the demineralization of the shrimp-shell powder. The shrimp-shell powders and fungal mycelia were separated after fermentation and extracted for chitin with 5% LiCl/DMAc solvent. Chitin isolates from the shells were found to have a protein content of less than 5%, while chitin isolates from the three fungal mycelia strains had protein content in the range of 10-15%. The relative molecular weights as estimated by GPC for all chitin samples were in the 10(5) dalton range. All samples displayed characteristic profiles for chitin in their FTIR and solid-state NMR spectra. All chitin samples evaluated with MTT and Neutral Red assays with three commercial cell lines did not display cytotoxic effects.

The degree of deacetylation of chitosan: advocating the first derivative UV-spectrophotometry method of determination.

The degree of deacetylation (DD) is increasingly becoming an important property for chitosan, as it determines how the biopolymer can be applied. Therefore, a simple, rapid and reliable method of determining the DD for chitosan is essential. In this report, the DD of chitosan was determined by nuclear magnetic resonance (NMR), linear potentiometric titration (LPT), ninhydrin test and first derivative UV-spectrophotometry (1DUVS). The DD was calculated on a per mol basis instead of on a per mass basis. This is important as the molecular weights of N-acetyl-d-glucosamine and d-glucosamine are different. By converting the mass of N-acetyl-d-glucosamine and d-glucosamine into mols and calculating for the percentage of d-glucosamine present in the chitosan sample, a more accurate estimation of the DD can be obtained. Of the four methods, there is good correlation between 1DUVS and NMR. The concentration of chitosan solution for 1DUVS analysis was standardised as 0.1000 mg chitosan per ml of 0.0100 M acetic acid solution. The presence of d-glucosamine was corrected for by a reference curve for N-acetyl-d-glucosamine. 1DUVS is easy to perform, sensitive and the interference of other contaminants to the results is minimal compared with the other three methods. Therefore, we advocate 1DUVS to be used as the standard methods for routine determination of DD of chitosan.

Detection of Mycoplasma pneumoniae from cerebrospinal fluid samples of pediatric patients.

Central nervous system manifestations are probably the most frequent extrapulmonary complications of infections due to Mycoplasma pneumoniae, occur mostly in children. In this study, we attempted to isolate M. pneumoniae and to detect the organism by polymerase chain reaction (PCR) from cerebrospinal fluid samples (CSF) of pediatric patients. Of the 244 CSF samples, no M. pneumoniae was isolated. Six (2.5%) of the CSF samples were positive by PCR amplification. More effort are necessary to isolate the organism from CSF samples in order to ascertain the role of M. pneumoniae in causing neurological complications.