The vestibular aqueduct in congenital deafness: evaluation by the axial projection

Thirty-two patients with congenital neurosensory hearing loss demonstrated dilatation of the peripheral limb of the vestibular aqueduct as visualized on pluridirectional tomograms. Multiple additional anomalies involving most frequently the cochlea (15 patients) but also the ossicles (three patients) or vestibule (one patient) were associated. The axial-pyramidal (Poschl) projection was of great value in evaluation of the vestibular aqueduct and cochlea. The technique, clinical correlation, and surgical implications are discussed.     

Developing resuscitation programmes in the community: the tasks ahead for the National Resuscitation Council

Singapore has a long way to go to becoming a 'heartsafe' society. Given our small size and culture of hard work in our country, we can achieve a state of good first response by our community citizens through public cardiopulmonary resuscitation and automated external defibrillators training programmes at various key sectors and through the implementation of public access defibrillation in a committed manner. For our second-line responders, investing in technology to improve response times and quality of chest compressions with earlier interventions will go a long way toward strengthening the chain of survival in the community. Building on this strong foundation and having a strong hospital-based cardiac arrest management system will ensure that those who achieve return of spontaneous circulation will more likely remain alive and be discharged from hospital in a neurologically optimal state.     

Advanced Cardiac Life Support guidelines 2011

The main emphasis in the Advanced Cardiac Life Support (ACLS) guidelines are in the areas of good quality chest compressions, ensuring normoventilation, removal of atropine from the cardiac arrest algorithm, removal of the use of the endotracheal route for drug administration, and renewed focus on the care provided after return of spontaneous circulation. In addition, the need for monitoring of quality of the various care procedures is emphasised. While the various ACLS procedures are being carried out, there is a need to minimise interruptions to chest compressions for maintenance of coronary perfusion pressures. In addition, the resuscitation team needs to continually look out for reversible causes of the cardiac arrest.     

Use of N, N-diethyl-p-phenylenediamine sulphate for the spectrophotometric determination of some phenolic and amine drugs

Spectrophotometric methods are proposed for the determination of drugs containing a phenol group [salbutamol sulphate (SLB), ritodrine hydrochloride (RTD), isoxsuprine hydrochloride (IXP)] and drugs containing an aromatic amine group [dapsone hydrochloride (DAP), sulfamethoxazole (SFM), and sulfadiazine (SFD)] in pharmaceutical dosage forms. The methods are based on coupling of N, N-diethyl-p-phenylenediamine sulphate with the drugs in the presence of KIO4 to give a green colored product (λmax at 670 nm) and a red colored product (λmax at 550 nm), respectively. Linear relationships with good correlation coefficients (0.9986-0.9996) were found between absorbance and the corresponding concentration of drugs in the range 1-7, 2-22, 1-17, 1.5-12, 2-25, and 2-21 μg mL-1 for SLB, RTD, IXP, DAP, SFM and SFD, respectively. Variable parameters such as temperature, reaction time and concentration of the reactants have been analyzed and optimized. The RSD of intra-day and inter-day studies was in the range of 0.2-1.0 and 0.4-1.0%, respectively. No interference was observed from common pharmaceutical adjuvants. The reliability and performance of the proposed methods was validated statistically; the percentage recovery ranged from 99.5 ± 0.1 to 99.9 ± 0.3%. Limits of detection were 0.14, 0.21, 0.51, 0.44, 0.33 and 0.37 μg mL-1 for SLB, RTD, IXP, DAP, SFM, and SFD, respectively.     

Treatment of chronic hepatitis C in patients with end-stage renal disease and hemophilia--the Singapore experience

OBJECTIVE: The aim of this study was to determine the response to treatment with interferon-alpha (IFN-alpha) in patients with chronic hepatitis C who had end-stage renal disease (ESRD) or hemophilia in Singapore. METHODS: Treatment-naive hepatitis patients with ESRD or hemophilia were given IFN-alpha(2a) 3 million units three times per week for 12 months in an open-label study. Hepatitis C virus RNA was determined before treatment, at the end of treatment and 6 months thereafter. Regular clinical examinations including blood counts and biochemistry were carried out during and after the treatment. RESULTS: Nine consecutive patients with ESRD (8 men and 1 woman) and 6 consecutive male patients with hemophilia, with a mean age of 43 and 40 years, received treatment. Patients in both groups were predominantly infected with hepatitis C virus genotype 1 and had significant cytopenia affecting all three cell lines during the treatment; only 1 patient developed serious neutropenia, temporarily demanding a reduction of his IFN dose. Biochemical and virological responses at the end of treatment were accomplished by 8 of the 9 (89%) patients with ESRD and 4 of the 6 (67%) patients with hemophilia; however, 1 patient with ESRD and 2 with hemophilia relapsed after the treatment. Four of the 7 patients with ESRD who had sustained virological response underwent successful kidney transplantation later on. CONCLUSION: Monotherapy with IFN-alpha for 12 months is safe for treatment of the patients with chronic hepatitis C who had ESRD or those with hemophilia. A higher sustained virological response rate was observed in patients with ESRD than in those with hemophilia (78 vs. 33%).     

Copy number variant analysis of human embryonic stem cells

Differences between individual DNA sequences provide the basis for human genetic variability. Forms of genetic variation include single-nucleotide polymorphisms, insertions/duplications, deletions, and inversions/translocations. The genome of human embryonic stem cells (hESCs) has been characterized mainly by karyotyping and comparative genomic hybridization (CGH), techniques whose relatively low resolution at 2-10 megabases (Mb) cannot accurately determine most copy number variability, which is estimated to involve 10%-20% of the genome. In this brief technical study, we examined HSF1 and HSF6 hESCs using array-comparative genomic hybridization (aCGH) to determine copy number variants (CNVs) as a higher-resolution method for characterizing hESCs. Our approach used five samples for each hESC line and showed four consistent CNVs for HSF1 and five consistent CNVs for HSF6. These consistent CNVs included amplifications and deletions that ranged in size from 20 kilobases to 1.48 megabases, involved seven different chromosomes, were both shared and unique between hESCs, and were maintained during neuronal stem/progenitor cell differentiation or drug selection. Thirty HSF1 and 40 HSF6 less consistently scored but still highly significant candidate CNVs were also identified. Overall, aCGH provides a promising approach for uniquely identifying hESCs and their derivatives and highlights a potential genomic source for distinct differentiation and functional potentials that lower-resolution karyotype and CGH techniques could miss. Disclosure of potential conflicts of interest is found at the end of this article.