Characterization of the calcitonin gene-related peptide receptor antagonist telcagepant (MK-0974) in human isolated coronary arteries

The sensory neuropeptide calcitonin gene-related peptide (CGRP) plays a role in primary headaches, and CGRP receptor antagonists are effective in migraine treatment. CGRP is a potent vasodilator, raising the possibility that antagonism of its receptor could have cardiovascular effects. We therefore investigated the effects of the antimigraine CGRP receptor antagonist telcagepant (MK-0974) [N-[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2-trifluoroethyl)azepan-3-yl]-4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridine-1-yl)piperidine-1-carboxamide] on human isolated coronary arteries. Arteries with different internal diameters were studied to assess the potential for differential effects across the coronary vascular bed. The concentration-dependent relaxation responses to human alphaCGRP were greater in distal coronary arteries (i.d. 600-1000 microm; E(max) = 83 +/- 7%) than proximal coronary arteries (i.d. 2-3 mm; E(max) = 23 +/- 9%), coronary arteries from explanted hearts (i.d. 3-5 mm; E(max) = 11 +/- 3%), and coronary arterioles (i.d. 200-300 microm; E(max) = 15 +/- 7%). Telcagepant alone did not induce contraction or relaxation of these coronary blood vessels. Pretreatment with telcagepant (10 nM to 1 microM) antagonized alphaCGRP-induced relaxation competitively in distal coronary arteries (pA(2) = 8.43 +/- 0.24) and proximal coronary arteries and coronary arterioles (1 microM telcagepant, giving pK(B) = 7.89 +/- 0.13 and 7.78 +/- 0.16, respectively). alphaCGRP significantly increased cAMP levels in distal, but not proximal, coronary arteries, and this was abolished by pretreatment with telcagepant. Immunohistochemistry revealed the expression and colocalization of the CGRP receptor elements calcitonin-like receptor and receptor activity-modifying protein 1 in the smooth muscle cells in the media layer of human coronary arteries. These findings in vitro support the cardiovascular safety of CGRP receptor antagonists and suggest that telcagepant is unlikely to induce coronary side effects under normal cardiovascular conditions.

Biochemical and molecular characterization of tyrosine hydroxylase deficiency in Hong Kong Chinese

Tyrosine hydroxylase deficiency is a rare neurotransmitter disorder affecting the rate-limiting step in catecholamine biosynthesis. There are about 40 cases reported worldwide. Here, we report the biochemical and molecular findings of eight unrelated Chinese patients with tyrosine hydroxylase deficiency. We have identified eight novel mutations with 5 missense, 2 nonsense and 1 splicing mutations in the TH gene, namely p.R153X, p.R169X, p.G294R, p.G315S, p.A385V, p.I394T, p.G408R, and c.1163+5G>C. The mutations of the TH gene in Chinese are heterogeneous.

Intestinal efflux transport kinetics of green tea catechins in Caco-2 monolayer model

The bioavailability of green tea catechins (GTCs), including epigallocatechin gallate (EGCG), epigal-locatechin (EGC), epicatechin gallate (ECG) and epicatechin (EC) is low in both animals and humans. The contribution of intestinal efflux to this low bioavailability has been suggested by previous studies. The objective of the present study was to investigate the kinetics of efflux transport of the four major GTCs in Caco-2 cell lines, to provide comparison on the efflux transport between each GTC. The basal-to-apical transport of each GTC at concentrations ranging from 15 to 265 μM was examined using the Caco-2 cell monolayer model. Transported amount of GTC was measured by high-performance liquid chromatography with electrochemical detection. Kinetic parameters, Vmax, Km and Vmax/Km were determined and compared among the four studied GTCs. The extent of basal-to-apical transport was, in descending order, EC > EGC > ECG ≅ EGCG. Kinetic studies indicated that active and saturable efflux transport of EC took place in Caco-2 cells, with a Km of 131 μM, a Vmax of 0.0249 nmol min cm−2 and an intrinsic clearance (Vmax/Km) of 0.19 μL min cm−2. No saturation could be observed for the efflux transport of EGC, ECG and EGCG even at concentrations up to about 200 μM, which may be due to their low affinity towards the transporters at the concentration range studied. In conclusion, the extent of efflux transport of GTCs in Caco-2 cells was, in descending order, EC > EGC > ECG ≅ EGCG, which may reflect the order of elimination occurring in the intestine. The kinetic studies showed the importance of efflux transporters in basal-to-apical transport of EC and suggests their role in the limited oral bioavailability of EC.

A novel mitochondrial DNA deletion in a Chinese girl with Kearns-Sayre syndrome

Kearns-Sayre syndrome is a rare disorder often caused by mitochondrial DNA rearrangement. The most commonly reported mitochondrial DNA deletion is 4977 bp in size spanning nucleotides 8469 and 13447. The clinical signs of Kearns-Sayre syndrome include chronic progressive external ophthalmoplegia, retinitis pigmentosa, heart block and cerebellar ataxia, as well as other heterogeneous manifestations including neuromuscular problems and endocrine disorders. Cardiac conduction defects can develop insidiously, leading to sudden death sometimes if not promptly recognised. This report focuses on the diagnosis of Kearns-Sayre syndrome in a Chinese girl who presented initially with short stature, delayed puberty, insidious onset of ptosis and later with typical features of Kearns-Sayre syndrome including complete heart block. Genetic analysis disclosed a novel 7.2 kilobases deletion in muscle tissue. Mitochondrial diseases have heterogeneous phenotypes and mutational analysis has proven to be an effective tool for confirming the diagnosis.

Hereditary spastic paraplegia: identification of an SPG3A gene mutation in a Chinese family

Hereditary spastic paraplegias are a heterogeneous group of chronic central motor system disorders, characterised by progressive lower limb spasticity. Hereditary spastic paraplegia is clinically classified into pure and complicated forms, by the absence or presence of additional neurological or extra-neurological features. Hereditary spastic paraplegias follow all modes of inheritance and the pure-form autosomal dominant type is the one most commonly reported. Spastic paraplegia 4, autosomal dominant (SPG4, MIM#182601) and spastic paraplegia 3, autosomal dominant (SPG3A, MIM#182600), account for most autosomal dominant hereditary spastic paraplegias. Using DNA mutation analysis, the authors identified an SPG3A missense mutation (p.R239C) in a Chinese family where three members have early-onset pure spastic paraplegia. To our knowledge, this is the first report of a gene mutation in hereditary spastic paraplegias in our locality. DNA-based diagnosis plays a key role in the early diagnosis of familial hereditary spastic paraplegias.

Autologous chondrocyte transplantation in the repair of full-thickness focal cartilage damage in rabbits

PURPOSE

To compare the efficacy of autologous chondrocyte transplantation (ACT) versus non-operative measures for cartilage repair in rabbits.

METHODS

Nine New Zealand white rabbits were used. Identical focal defects were created in the articular cartilage of both knees. One month later, the right knee was repaired via ACT, while the left knee was left untreated (control group). The quality of cartilage tissues in both knees was compared 3 months later, according to the quantitative analysis of glycosaminoglycan (GAG) in the cartilage and macroscopic examination of histology using the Brittberg/International Cartilage Research Society (ICRS) score.

RESULTS

Microscopic examination showed enhanced regeneration following ACT repair. Quantification analysis revealed significantly higher cellular expression of GAG in the ACT-treated knees (1.12 vs 0.81 microgram GAGs/mg protein, p=0.008). The mean Brittberg/ICRS score was significantly higher in the treated knees (6.00 vs 1.89, p=0.007).

CONCLUSION

ACT is superior to non-operative measures for repairing focal cartilage defects, as determined by favourable histological and immunohistological outcomes at the cellular level.

Role of polymorphisms of the inflammatory response genes and DC-SIGNR in genetic susceptibility to SARS and other infections

1. A genetic risk-association study involving more than 1200 subjects showed individuals homozygous for L-SIGN tandem repeats are less susceptible to SARS infection. 2. This was supported by in vitro binding studies that demonstrated homozygous L-SIGN, compared to heterozygous, had higher binding capacity for SARS coronavirus (SARS-CoV), with higher proteasome-dependent viral degradation. In contrast, homozygous L-SIGN demonstrated lower binding capacity for HIV1-gp120.3. Genetic-association studies for single nucleotide polymorphisms of the inflammatory response genes, namely TNF-alpha, INF-alpha, INF-beta, INF-gamma, IL1-alpha, IL1-beta, IL-4, IL-6 and iNOS, failed to show a significant association with SARS clinical outcomes or susceptibility.

Pantothenate kinase-associated neurodegeneration in two Chinese children: identification of a novel PANK2 gene mutation

Pantothenate kinase-associated neurodegeneration (formerly Hallervorden-Spatz syndrome), the most prevalent form of neurodegeneration with brain iron accumulation, is a rare degenerative brain disease characterised by predominantly extrapyramidal dysfunction resulting from mutations in the PANK2 (pantothenate kinase 2) gene. Using DNA mutation analysis, the authors identified a novel missense mutation (P354L) in exon 4 of the PANK2 gene in an adolescent with classic pantothenate kinase-associated neurodegeneration. DNA-based diagnosis of pantothenate kinase-associated neurodegeneration plays a key role in determination, and can make the diagnosis more simply, directly, and economically because it obviates the need for unnecessary biochemical tests. Once pantothenate kinase-associated neurodegeneration-like symptoms are identified, mutation analysis and target screening for the family of the proband can provide efficient and accurate evidence of pantothenate kinase-associated neurodegeneration inheritance.

Use of garden organic compost in vegetable production under contrasting soil P status

Little research has been carried out on the agronomic value of compost produced from garden organics for vegetable production. A field experiment was established in Camden, near Sydney, Australia, to (i) evaluate the effect of the compost on vegetable production and soil quality relative to conventional practice, (ii) compare vegetable production under high and low soil P status, and (iii) monitor the changes in soil P concentration under two compost treatments relative to conventional farmers’ practice. After three successive crops (broccoli, eggplant and cabbage), results indicate that compost (120 dry t/ha) and half-compost (60 dry t/ha supplemented by inorganic fertilisers) treatments can produce similar yield to the conventional practice of using a mixture of poultry manure and inorganic fertiliser. Furthermore, similar yields were achieved for three different crops grown under high and low P soil conditions, clearly demonstrating that the high extractable soil P concentrations currently found in the vegetable farms of Sydney are not necessary for maintaining productivity. The compost treatments also significantly increased soil organic carbon and soil quality including soil structural stability, exchangeable cations, and soil biological properties. Importantly, the compost treatment was effective in reducing the rate of accumulation of extractable soil P compared with the conventional vegetable farming practice. Our results highlight the potential for using compost produced from source separated garden organics in reversing the trend of soil degradation observed under current vegetable production, without sacrificing yield.

Study of wrist posture, loading and repetitive motion as risk factors for developing carpal tunnel syndrome

Occupational risk factors of carpal tunnel syndrome (CTS) are popular current research targets, with main emphasis put on wrist posture and dynamics. In this study, we do not intend to pinpoint individual occupations, but aim to identify high risk wrist postures and actions which may occur across various occupations. It is hoped that prevention can thus be instituted in a general population by directing at the particular causative wrist actions rather than exclusively targeting isolated occupations. We performed a case-control study with 166 cases and 111 controls recruited from different hospitals in Hong Kong in 2004. All cases and controls completed the survey on their general health condition, smoking status, wrist posture and motion as well as psychosocial status at the time of diagnosis of CTS. Frequent flexion OR = 4.436 (95% CI: 1.833-10.734), frequent extension OR = 2.691 (95% CI: 1.106-6.547) of the wrist were found to be associated with CTS. Frequent sustained forceful motion of the wrist OR = 2.588 (95% CI: 1.144-5.851) was also found to be associated with CTS. Neutral wrist position and repetitive wrist motion were not associated with CTS. Adjustment was made for age, sex, BMI, smoking and psychosocial stress. Our study confirms that frequent flexion, extension and sustained force of the wrist increase the risk of developing CTS.

Carnitine-acylcarnitine translocase deficiency in three neonates presenting with rapid deterioration and cardiac arrest

We report on three Chinese neonates with carnitine-acylcarnitine translocase deficiency. They presented within the first 48 hours of life. Two neonates were found in cardiac arrest; one of them survived after resuscitation. The third neonate suddenly developed cardiorespiratory insufficiency and succumbed eventually. The clustering of three cases in 5 years suggests that carnitine-acylcarnitine translocase deficiency is not rare in our Chinese population. We advocate that investigation for metabolic diseases including carnitine-acylcarnitine translocase deficiency should be performed in cases of sudden infant death and unexplained abrupt clinical deterioration in the early neonatal period. Non-ketotic hypoglycaemia is an early clue. The mainstay of initial treatment is glucose infusion at a rate greater than 7 mg/kg/minute, which inhibits beta-oxidation of fatty acids (the defective enzymatic steps in carnitine-acylcarnitine translocase deficiency) and thus prevents the accumulation of toxic long-chain acylcarnitines.

An Asia Pacific six-country study on HIV-related discrimination: Introduction

This paper outlines a six-country study of institutionalised forms of HIV/AIDS-related discrimination in the Asia-Pacific region. Although recognised as a barrier to disease prevention and treatment, very limited data are available on the effects of institutionalised HIV-related stigma and discrimination. Understanding the forms of discrimination within the institutions where they occur is the first step to identifying effective ways of promoting compassionate, non-discriminatory treatment of PLWHA. Thus, the goal of this research project was to document institutional discrimination against PLWHA, as guided by the UNAIDS Protocol for the Identification of Discrimination Against People Living with HIV (2000), in six Asian countries: India, Thailand, Philippines, China, Vietnam and Indonesia. As a precursor to the six individual studies, this paper provides a brief overview of the literature on HIV discrimination, and then describes the UNAIDS Protocol and the shared methodological considerations relevant to all of the study sites. Commonalities in sampling, procedures and analysis are also discussed.

Determining the agronomic value of composts produced from garden organics from metropolitan areas of New South Wales, Australia

About 0.3 million t/year of composted garden organics (CGO) including mulches and soil conditioners are produced annually in New South Wales, Australia, although only a small proportion of this material (<4%) is used in agriculture. A lack of information on product characteristics and agronomic performance has limited the development of agricultural markets for CGO products. These CGO products are the coarse and fine fractions separated by screening after composting. This paper presents the results of a survey of CGO mulches and soil conditioners (unblended or blended with a mixture of other organic materials including biosolids, animal manures and paper), which are commercially produced in the metropolitan areas of New South Wales and assesses their agronomic and soil amendment values in terms of chemical and biological properties. It also evaluates the short-term effects of applying increasing rates (0, 25, 50 and 100 t/ha) of selected composted soil conditioners on radish growth in a pot experiment. The mulch products had low nutrient concentrations but had high carbon (C) contents (mean C = 45%) and C/Nitrogen (N) ratios (mean C/N = 72) and are most suitable for use as surface mulch. The unblended soil conditioners were low in nutrients, particularly N (average total N = 1.0%, range 0.9–12%), and had lower and variable C contents. The pot trial results indicated lack of growth response of radish at application rates up to 100 t/ha of unblended soil conditioners from garden organics. The blended soil conditioners were more variable in quality and as confirmed by pot trial results produced highly variable plant responses. The high variability in product quality and performance of the soil conditioners, particularly the blended products might be related to the source and type of blending material as well as the composting conditions used in the manufacturing process. These results highlight the need to improve compost quality and consistency and the need for further research to advance understanding of the benefits using CGO in terms of improving soil quality, crop productivity and net economic returns to growers.

The rate of glove perforations in orthopaedic procedures: single versus double gloving. A prospective study

Glove perforation during surgery has always been a matter of concern as it increases the infection rate and the risk of transmission of blood borne diseases. To determine the common causes, the site and the awareness of glove perforations in orthopaedic surgery, a prospective study was conducted to assess the rate of glove perforation during 130 consecutive orthopaedic operations. All gloves worn by the surgical team were assessed after the surgery using the water-loading test. A total of 1452 gloves were tested, and the rate of perforation was 3.58%. Most of these perforations (61.5%) were unnoticed. The main surgeons had the most perforations (76.9%), followed by first assistants (13.5%) and second assistants (9.6%). Most perforations occurred at the non-dominant hand. The commonest site of perforation was the index finger followed by the thumb. Shearing force with instruments accounted for 45% of the noticed perforations. Majority of these occurred during nailing procedures (33%) and internal fixation without the use of wires (19%). Our rate of glove perforation is similar to other series. Most of them went unnoticed and were mainly due to shearing injuries rather than perforation by sharps. Therefore, there is an increased risk of contamination and break in asepsis during surgery.

Electrochemical degradation of 4-chlorophenol at nickel-antimony doped tin oxide electrode

The effectiveness of a novel nickel-antimony doped tin oxide electrode for electrochemical degradation of organic pollutants was investigated using 4-chlorophenol (4-CP) as a model toxic organic. The experimental results demonstrate that the optimal Ni content was at Ni:Sn=1:500 in atomic ratio in the precursor coating solution, whereas the Sb:Sn ratio was set at 8:500. Using the electrode prepared with the optimal Ni doping ratio for 4-CP degradation, the charge-based efficiencies were up to 89 microg C(-1) for 4-CP destruction and 15 microg C(-1) for TOC removal, which were considerably higher than the efficiencies observed for other electrodes. It is suggested that the enhancement of the electrode for electrochemical oxidation of organics could be attributed to the production of hydroxyl radicals in anodic water electrolysis.

HIV discrimination: integrating the results from a six-country situational analysis in the Asia Pacific

The findings of the six independent studies on institutional forms of HIV discrimination in the Asia Pacific presented in this Special Issue of AIDS Care are integrated. At first glance, the general pattern of the results across the study sites suggests that discrimination is most pertinent in the domain of 'practice' rather than in the domains of law or institutional policy. On closer analysis, however, utilising the qualitative data, this conclusion does not take sufficient account of the cultural context within which the interpersonal interaction (practice) between the health carers and people living with HIV/AIDS occurs. Limitations on the use of anti-discrimination legislations and protective written policies for reducing discrimination in these contexts are discussed. The need for alternative approaches to thinking about discrimination intervention is raised and this is done through a consideration of the strategy of universal precautions.

Future research on structural and institutional forms of HIV discrimination

There is scant research into HIV discrimination, particularly structural and institutional forms of it. This appears, in part, to arise from a prevailing view that the solutions to HIV discrimination are known a priori and in the absence of additional data. The six country studies into HIV discrimination presented in this AIDS Care supplement suggest that this is not the case. There needs to be an acceptance that if the issue of HIV discrimination is to be tackled successfully and based on evidence, then incremental and effortful steps need to be taken to develop that evidence base. This is discussed.

Institutional and structural forms of HIV-related discrimination in health care: a study set in Beijing

This paper presents key findings of a situational analysis of institutional and structural levels of HIV/AIDS-related discrimination in Beijing, China, with a focus on the area of health care. Initially slow to respond to the presence of HIV, China has altered its approach and enacted strict legislative protection for people living with HIV/AIDS (PLWHA). In order to determine whether this has altered discrimination against PLWHA, this study examined existing legislation and policy, and interviewed key informants working in health care and PLWHA. The overall findings revealed that discrimination in its many forms continued to occur in practice despite China's generally strong legislative protection, and it is the actual practice that is hindering PLWHAs' access to health services. A number of legislative and policy gaps that allow discrimination to occur in practice were also identified and discussed. The paper concludes with a call to rectify specific gaps between legislation, policy and practice. An understanding of the underlying factors that drive discrimination will also be necessary for effective strategic interventions to be developed and implemented.

Nitrogen removal from the saline sludge liquor by electrochemical denitrification

Sludge liquor from the sludge dewatering process has a high ammonia content. In the present study, a lab-scale electrochemical (EC) system with a pair of Ti electrode plates was used for treating the sludge centrate liquor of digested wastewater sludge with a NH4(+) - N content of around 500 mg/L. The sludge liquor had a high salinity due to seawater being used for toilet flushing in Hong Kong. The results show that the EC process is highly effective for denitrification of the saline sludge liquor. Complete nitrogen removal could be achieved within 1 hr or so. The rate of EC denitrification increased with the current intensity applied. The best current efficiency for nitrogen removal was obtained for a gap distance between the electrodes at 8 mm. Electro-chlorination was considered to be the major mechanism of EC denitrification. The formation of chlorination by-products (CBPs) appeared to be minimal with the total trihalomethanes (THM) detected at a level of 300 microg/L or lower. The power consumption for EC denitrification was around 23 kWh/kg N. Additional electro-flocculation with a pair of iron needle electrodes could enhance the flocculation and subsequent sedimentation of colloidal organics in the sludge liquor, increasing the organic removal from less than 30% to more than 70%. Therefore, the EC process including both electro-denitrification and electro-flocculation can be developed as the most cost-effective method for treatment of the saline sludge liquor.

A method for the quantitative analysis of the layering of HIV-related stigma

HIV-related stigma is regarded as one of the major barriers in the development of effective prevention and care programs; but the stigma associated with HIV stigma is not a singular entity. The stigma of the infection is layered with other stigmas, such as those associated with the routes of transmission (e.g., sex work and injecting drug use) and personal characteristics (e.g., race, religion, ethnicity and gender). In developing programs and policies to overcome HIV-related stigma, cognisance needs to be taken of all the sources of stigma, and how they may interact. A novel method is described for examining the layers of HIV/AIDS-related stigma, and secondary data are adapted to illustrate this. The importance of understanding the layering of stigma for the development of effective interventions is also discussed.

Herpetic shoulder paresis in a Chinese elderly patient

A patient with left shoulder girdle weakness secondary to herpetic myotomal paresis is reported. Needle electromyography revealed denervational discharge from the left supraspinatus, deltoid, and brachioradialis muscles, compatible with a radiculopathy that was relevant to his myotomes affected by zoster infection. The patient was managed with range-of-movement and strengthening exercises as well as pain relief for post-herpetic neuralgia. Further studies are required to determine whether antiviral treatment can limit the extent of motor deficit and hasten recovery. Zoster paresis should be one of the differential diagnoses of girdle muscle weakness.