Hong Kong's experience on the use of extracorporeal membrane oxygenation for the treatment of influenza A (H1N1)

OBJECTIVE

To report Hong Kong's experience on the use of extracorporeal membrane oxygenation for the treatment of acute respiratory distress syndrome caused by influenza A (H1N1).

DESIGN

Multi-centred, retrospective observational study.

SETTING

Intensive care units in Hong Kong.

PATIENTS

Recipients of extracorporeal membrane oxygenation for confirmed influenza A (H1N1) infection from 1 May 2009 to 28 February 2010.

MAIN OUTCOME MEASURE

Hospital mortality.

RESULTS

During the study period, 120 patients were mechanically ventilated in intensive care units, among whom seven received veno-venous extracorporeal membrane oxygenation. The median (interquartile range) age of the latter patients was 42 (39-50) years, four had various chronic illnesses and one had a body mass index of greater than 30 kg/m². The median (interquartile range) time from symptom onset to hospital admission was 5 (4-7) days. Corresponding values for the duration of extracorporeal membrane oxygenation, mechanical ventilation, intensive care unit stay, and hospital stay were 6 (6-10), 19 (11-25), 19 (18-30), and 31 (25-55) days, respectively. One patient died (hospital mortality, 14%) and six made full recoveries. All seven patients received oseltamivir; in addition three received intravenous zanamivir, four received convalescent plasma, and one received hyperimmune immunoglobulin. Nosocomial infection was the commonest complication. There was no life- or limb-threatening complication directly attributable to extracorporeal membrane oxygenation.

CONCLUSION

In response to the pandemic of influenza A (H1N1), some intensive care units in Hong Kong were able to offer extracorporeal membrane oxygenation to selected cases. In this small series, patient outcomes were similar to those reported in other observational studies, indicating that intensive care units in Hong Kong are capable of successfully introducing this technology. However, the cost-effectiveness and optimal delivery of this strategy remain uncertain.

Phenotypic and genotypic characteristics of Mycobacterium isolates from fighting fish Betta spp. in Malaysia

Mycobacteriosis due to mycobacteria is one of the most common bacterial diseases in ornamental fish. We describe here the phenotypic and genotypic characteristics of Mycobacterium isolates from fighting fish Betta spp. using ATCC Mycobacterium marinum, Mycobacterium fortuitum and Mycobacterium chelonae as references. A total of four isolates (M1, M2, M3, M4) were obtained from four out of 106 fish samples using selective agar, and identified to Mycobacterium genus using acid-fast staining and 16s rRNA gene-based genus specific polymerase chain reaction. DNA sequencing and NCBI-BLAST analysis further identified isolate M1 as M. marinum and isolates M2, M3, M4 as M. fortuitum. Morphological, physiological and biochemical tests were carried out for phenotypic characterizations. Universal M13 and wild-type phage M13 RAPD dendogram was generated to illustrate the genetic relationship of the isolates and reference strains.

Clinical features of acute renal failure associated with hepatitis A virus infection

Acute hepatitis A (AHA) is one of the most common infectious diseases; it is usually a self-limiting disease affecting the liver. Although extrahepatic manifestations are not common, some cases have been reported associated with acute renal failure. We reviewed the clinical features of patients with AHA complicated by acute renal failure (ARF group) and compared them with patients with noncomplicated AHA (non-ARF group). The medical records of 208 consecutive patients with AHA who were diagnosed between January 2003 and October 2008 were reviewed. We identified 15 patients (7.2%) with ARF associated with AHA. There were no differences between the ARF and non-ARF group with regard to gender and age. The peak value of alanine aminotransferase (ALT) (median: 6060 IU/L vs 1792 IU/L, P < 0.001), prothrombin time (PT) (International normalized ratio, median 1.72 vs 1.10, P < 0.001), and total bilirubin level (median: 9.6 mg/dL vs 6.3 mg/dL, P = 0.04) were significantly higher in the ARF than in the non-ARF group. Twelve patients (80%) recovered completely with haemodialysis (seven patients, 46.7%) or only conservative management (five patients, 33.3%), while one patient underwent liver transplantation because of fulminant hepatic failure, and two patients died because of fulminant hepatic failure. There were no deaths among patients with noncomplicated AHA in the non-ARF group. Five patients underwent kidney biopsy; two patients were diagnosed with acute tubular necrosis, two patients with acute interstitial nephritis with IgA nephropathy and one patient with acute tubulointerstitial nephritis. All patients in the ARF group had microscopic haematuria and proteinuria (100%vs 31.1%, P < 0.001). Urine sodium levels were more than 10 mEq/L in 10 patients. The findings of high urinary sodium concentrations, microscopic haematuria and proteinuria did not support the diagnosis of hepatorenal syndrome (HRS). Patients with AHA with ARF had higher ALT levels, more prolonged PTs, and higher total bilirubin levels. The prognosis for these patients was poorer than for those without ARF. However, the patients with ARF and nonfulminant AHA had recovered with proper treatment and should not be confused with patients that have HRS.

High viremia, prolonged Lamivudine therapy and recurrent hepatocellular carcinoma predict posttransplant hepatitis B recurrence

Hepatitis B virus (HBV) recurrence following orthotopic liver transplantation (OLT) is generally preventable by prophylaxis with hepatitis B immunoglobulin (HBIG) and lamivudine (LAM). However, HBV recurrence sometimes develops despite prophylaxis. This study assessed posttransplant outcomes and identified predictors of HBV recurrence. We analyzed the outcomes of 209 consecutive patients positive for hepatitis B surface antigen who underwent OLT, who received either combination prophylaxis with HBIG and LAM (89.0%) or HBIG monoprophylaxis (11.0%). The median follow-up was 36.8 months (range, 1.0-84.4). Posttransplant HBV recurrence occurred in 22 patients (10.5%), including 13 patients with drug-resistant mutations. HBV recurrence was observed in six patients after hepatocellular carcinoma (HCC) recurrence. Independent predictors of HBV recurrence were recurrent HCC (p < 0.001), LAM therapy >1.5 years (p = 0.001) and high HBV DNA titers (> or =10(5) copies/mL) at OLT (p = 0.036). In conclusion, high viremia at OLT and prolonged exposure to LAM should be further stressed as main predictors of HBV recurrence.

The first novel influenza A (H1N1) fatality despite antiviral treatment and extracorporeal membrane oxygenation in Hong Kong

We report the first fatality caused by novel influenza A (H1N1) infection despite having the diagnosis confirmed and being given antiviral treatment after hospitalisation. This patient was also the first with influenza A (H1N1) to be supported with extracorporeal membrane oxygenation in Hong Kong. Although extracorporeal membrane oxygenation is an effective means of supporting patients with refractory hypoxaemia on high mechanical ventilatory support, it is labour-intensive and technically demanding. We also discuss the challenges faced when managing this case.

Impact on trauma patient management of installing a computed tomography scanner in the emergency department

BACKGROUND

Computed tomography (CT) plays a central diagnostic role for trauma patients. A 16-slice multi-detector CT scanner was installed in the emergency department (ED) of Prince of Wales Hospital in December 2004. The aims of this study were to evaluate the impact of the CT scanner within the ED on trauma management and to compare the utilisation patterns of trauma CT before and after the introduction of EDCT.

METHODS

Analysis of prospectively collected trauma registry data. All consecutive trauma cases admitted through the ED that underwent CT between June 2004 and June 2005 (6 months before and after EDCT installation) were included. A positive CT was defined as the identification (by a specialist radiologist) of a significant finding which was consistent with injury.

RESULTS

There were 226 and 202 trauma patients in the 6 months before and after EDCT installation, respectively. 111 (49.1%) patients underwent CT scanning before EDCT compared with 110 (54.5%) afterwards. 72 (65%) patients had CT scans performed before admission to definitive care compared with 99 (90%) after EDCT installed (p<0.0001, chi(2) test). Mean time from arrival to first CT was shorter after EDCT (102 min vs. 197 min, p=0.011). Mean trauma room length of stay increased after EDCT was implemented (106 min vs. 80 min; p<0.001). Median time to urgent operation (<6h) was less with EDCT (134 min before vs. 112 min after). No changes in median time to neurosurgical operation (138 min before vs. 148 min after); mean length of stay (12.8 days before vs. 12.5 days after); or mortality (8 patients before vs. 7 patients after). There were 203 scans (1.8/patient) done before EDCT compared with 226 scans (2.5/patient) after. There was no difference in the number of scans done by body region or the proportion of positive scans (32% before vs. 30% after). Logistic regression confirmed that after adjusting for injury severity and admission physiology, time to first CT was shorter (p=0.0307) but ED length of stay was increased (p<0.0001).

CONCLUSION

After the installation of EDCT, more trauma patients had CT scanning before definitive care, and scans were done sooner, with no significant increase in the number of unnecessary scans.

Long-term low-dose amiodarone therapy in the management of ventricular and supraventricular tachyarrhythmias: efficacy and safety

BACKGROUND

Amiodarone hydrochloride has been in use for two decades for the control of ventricular and supraventricular arrhythmias. Established and emerging evidence indicates that amiodarone has an antiarrhythmic efficacy superior to that of most other drugs.

HYPOTHESIS

The study was undertaken to evaluate the efficacy and acceptability of low-dose amiodarone therapy in the long-term management of supraventricular and ventricular tachyarrhythmias.

METHODS

A total of 124 patients with symptomatic drug-refractory or life-threatening arrhythmias managed with low-dose oral amiodarone therapy over a 10-year period was analyzed retrospectively. Of these, 45 patients (36%) had ventricular arrhythmias, 52 (42%) had atrial arrhythmias, and 27 (22%) had atrioventricular reentry tachycardia. Loading doses of amiodarone 600 mg daily for 1 week were administered for supraventricular arrhythmias and 600-1200 mg daily for 2 weeks for ventricular arrhythmias. Maintenance daily doses were 194 +/- 48 and 206 +/- 55 mg, respectively. Mean treatment duration was 32 +/- 28 months, with 326.3 patient years of therapy.

RESULTS

Of 39 patients with sustained ventricular tachyarrhythmias, the actuarial incidence of satisfactory arrhythmia control (absence of sudden cardiac death or nonfatal arrhythmia recurrence) was 78% at 1 year and 71% at 2 years. Satisfactory control of supraventricular arrhythmias (mean ventricular rate < 100/min with significant symptomatic improvement for sustained atrial arrhythmias and < 1 attack per year for paroxysmal atrial or atrioventricular arrhythmias) was achieved in 73, 65, and 62% of patients at 1, 2, and 3 years, respectively. The cumulative incidence of amiodarone-related adverse effects was 5.8 per 100 patient years, with drug withdrawal required in 12 patients (9.7%). Fifteen patients had thyroid dysfunction, 2 had hepatic toxicity, and 1 developed nonfatal pulmonary fibrosis. Overall, the incidence of successful use of amiodarone (satisfactory arrhythmia control and freedom from side effects) was 67, 59, and 53% at 1, 2, and 3 years, respectively.

CONCLUSIONS

The results of this study suggest that the efficacy of low-dose amiodarone therapy in the management of serious ventricular and supraventricular arrhythmias would be similar to those achieved with higher doses, but with a much more acceptable side effect profile.

Biochemical and pharmacological characterization of different recombinant acid alpha-glucosidase preparations evaluated for the treatment of Pompe disease

Pompe disease results in the accumulation of lysosomal glycogen in multiple tissues due to a deficiency of acid alpha-glucosidase (GAA). Enzyme replacement therapy for Pompe disease was recently approved in Europe, the U.S., Canada, and Japan using a recombinant human GAA (Myozyme, alglucosidase alfa) produced in CHO cells (CHO-GAA). During the development of alglucosidase alfa, we examined the in vitro and in vivo properties of CHO cell-derived rhGAA, an rhGAA purified from the milk of transgenic rabbits, as well as an experimental version of rhGAA containing additional mannose-6-phosphate intended to facilitate muscle targeting. Biochemical analyses identified differences in rhGAA N-termini, glycosylation types and binding properties to several carbohydrate receptors. In a mouse model of Pompe disease, glycogen was more efficiently removed from the heart than from skeletal muscle for all enzymes, and overall, the CHO cell-derived rhGAA reduced glycogen to a greater extent than that observed with the other enzymes. The results of these preclinical studies, combined with biochemical characterization data for the three molecules described within, led to the selection of the CHO-GAA for clinical development and registration as the first approved therapy for Pompe disease.

[The provincial medical system during the early days of Koryo Dynasty]

This article explores the setup and development of the provincial medical system during the early days of Koryo (918-1392) Dynasty. Under the reign of King HyunJong (1009-1031) the dualistic medical system of the UiSa (a medical officer) and the YakJumSa (a provincial medical officer) was established. The former, the officer of central government, were sent to the local government, and the latter, the successor of provincial powerful clan, operated the YakJum. The Uisa supervised the YakJumSa in 13 local governments, and it indicates the will and the limitation of the power of Koryo government. On the other hand, a great number of the YakJumSa were spreaded throughout the country except the capital and the vice capital, and it means the development of medical system during the early days of Koryo. The missions of the Uisa and the YakJumSa were instructing the medical students, collecting the tribute herbs, treatment, and relieve the poor people. And they just took the right of collecting tax of the land as their salaries, and it was different from the another officers. This dualistic medical system of the UiSa and the YakJumSa got under way in the reign of King MoonJong (1046-1083). But after the reign of King YeJong (1105-1122) the YakJumSa became the only provincial medical officer as the UiSa had been perished for reducing the ruling system. So the monistic medical system of the YakJumSa was the final provincial medical system of Koryo. Despite accomplishing the nationwide medical network with the YakJumSa, Koryo government failed to maintain and develop the provincial medical system with the UiSa. And it caused the difference of medical standard between the ruling class of the capital and the people of the province. Therefore, it can be said that the important principal of the medical system of Koryo was hierarchy accordance with the regional difference.

A case of takotsubo cardiomyopathy: transient left ventricular apical ballooning

A 78-year-old woman was admitted to hospital with central chest pain and the electrocardiographic and cardiac marker changes typical of acute anterior myocardial infarction. Coronary angiography revealed normal epicardial coronary arteries, and left ventriculography showed apical akinesis as well as basal hyperkinesis. This is a case of transient left ventricular apical ballooning or takotsubo cardiomyopathy, possibly attributable to catecholamine-mediated myocardial stunning.

Contamination of mercury in tongkat Ali hitam herbal preparations

The DCA (Drug Control Authority), Malaysia has implemented the phase three registration of traditional medicines on 1 January 1992. As such, a total of 100 products in various pharmaceutical dosage forms of a herbal preparation found in Malaysia, containing tongkat Ali hitam, either single or combined preparations, were analyzed for the presence of a heavy toxic metal, mercury, using atomic absorption spectrophotometer, after performing a simple random sampling to enable each sample an equal chance of being selected in an unbiased manner. Results showed that 26% of these products possessed 0.53-2.35 ppm of mercury, and therefore, do not comply with the quality requirement for traditional medicines in Malaysia. The quality requirement for traditional medicines in Malaysia is not exceeding 0.5 ppm for mercury. Out of these 26 products, four products have already registered with the DCA, Malaysia whilst the rest, however, have not registered with the DCA, Malaysia.

[The medical theory of Lee Je-ma and its character]

Lee Je-ma 1837-1900) was a prominent scholar as well as an Korean physician. classified every people into four distinctive types: greater yang [tai yang] person, lesser yin [shao yin] person, greater yin [tai yin] person, lesser yin [shao yin] person. This theory would dictate proper treatment for each type in accordance with individual differences of physical and temperament features. Using these four types he created The Medical Science of Four Types. This article is intended to look into the connection between Lee Je-Ma's 'The Medical Science of Four Types' and 'The Modern' with organizing his ideas about the human body and the human being. Through The Modern, the theory of human being underwent a complete change. Human being in The Premodern, which was determined by sex, age and social status has been changed to the individual human being, which is featured by equality. Lee Je-Ma's medical theory of The Medical Science of Four Types would be analyzed as follow. His concept of human body is oriented toward observable objectivity. But on the other hand, it still remains transcendent status of medical science, which is subordinated by philosophy. According to Lee Je-Ma's theory of human being, human is an equal individual in a modern way of thinking, not as a part of hierarchical group. But on the other hand, it still remains incomplete from getting rid of morality aspect that includes virtue and vice in the concept of human body. The common factors in Lee Je-Ma's ideas about the human body and the human being is 'Dualism of mind and body that means all kinds of status and results depends on each individual. As is stated above, Lee Je-Ma's medical theory has many aspects of The Modern and it proves that Korean traditional medicine could be modernized by itself.

A comparison of outcomes after indocyanine green and trypan blue assisted internal limiting membrane peeling during macular hole surgery

AIMS

To compare the anatomical and visual outcomes of macular hole repair surgery using indocyanine green (ICG) or trypan blue (TB) staining of the internal limiting membrane (ILM).

METHOD

Retrospective analysis of 37 eyes from 37 consecutive patients with stage 2, 3, and 4 idiopathic macular holes who underwent macular hole repair by one surgeon using the same technique but utilising different dyes for ILM peeling. In 19 patients ICG was used while 18 patients had TB. The anatomical and visual results in these two groups were compared.

RESULTS

There were no significant differences in the demographic and macular hole characteristics of the ICG and TB groups. Macular hole closure was achieved in 91.9% of all patients of which the ICG group had an 89.5% hole closure rate and the TB group had a 94.4% hole closure rate. After excluding cases with failed hole closure and other vision affecting complications, there was no significant difference between the preoperative visual acuities in the TB and ICG groups but the postoperative visual acuities were better in the TB than the ICG group (p = 0.036). The TB group also had more Snellen lines of improvement than the ICG group (2.94 v 1.79 lines; p = 0.046).

CONCLUSION

TB appears to be less toxic than ICG when used in dye assisted peeling of ILM during macular hole repair as reflected by the better visual results in the TB group of patients.

Determination of lead in Smilax myosotiflora herbal preparations obtained in Malaysia

The DCA (Drug Control Authority), Malaysia implemented the phase 3 registration of traditional medicines on 1 January 1992 with special emphasis on the quality, efficacy and safety (including the presence of heavy metals) in all pharmaceutical dosage forms of traditional medicinal preparations. As such, a total of 100 traditional medicinal preparations, containing Smilax myosotiflora, in various pharmaceutical dosage forms, which were bought in the Malaysian market, were analysed for lead content using atomic absorption spectrophotometry. Results showed that 15% of the products analysed possessed 10.23-23.05 ppm of lead, and therefore, do not comply with the quality requirement for traditional medicines in Malaysia. The quality requirement for traditional medicines in Malaysia is that they should not exceed 10 ppm of lead. Out of these 15 products, five products exhibited 10.23-23.05 ppm of lead, in fact they have already been registered with the DCA Malaysia. However, the rest of the products, which possessed 12.24-20.72 ppm of lead, have still not been registered with the DCA Malaysia. Although this study successfully showed that only 85% of the products complied with the quality requirement for traditional medicines in Malaysia pertaining to lead, they cannot, however, be assumed to be safe from lead contamination because of batch-to-batch inconsistency.

Experimental studies of the material properties of the forewing of cicada(Homóptera, Cicàdidae)

Detailed investigations on the structural and mechanical properties of the forewing of the cicada were carried out. Measurement of the structures of the wings showed that the thickness of the membrane of each cell and the diameter of each vein were non-uniform in both the longitudinal and transverse directions, and their means were approximately 12.2 and 133.3 μm,respectively. However, the aspect ratios of the wings and the bodies were quite uniform and were approximately equal to 2.98 and 2.13, respectively. Based on the measured thickness, mass and area of the membranes of the cells,the mean density and the mean area density of the wing were approximately 2.3 g cm-3 and 2.8×10-3 g cm-2,respectively. In addition, the diameters of the veins of the wings, including the diameters of the holes in the vein of the leading edge, were examined. The mechanical properties of the wing were investigated separately by nanoindentation and tensile testing. The results indicated that the mean Young's modulus, hardness and yield stress of the membranes of the wings were approximately 3.7 GPa, 0.2 GPa and 29 MPa, respectively, and the mean Young's modulus and strength of the veins along the direction of the venation of wings were approximately 1.9 GPa and 52 MPa, respectively. Finally, the relevant results were briefly analyzed and discussed, providing a guideline to the biomimetic design of the aerofoil materials of micro air vehicles.

Effect of Eurycoma longifolia Jack on orientation activities in middle-aged male rats

The effects of various fractions of Eurycoma longifolia Jack were studied on the orientation activities of the inbred, adult middle-aged Sprague-Dawley rats, 9 months old and retired breeders towards the receptive females (anogenital sniffing, licking, mounting), the environment (climbing, raring, exploration), themselves (nongenital grooming, genital grooming) and mobility (restricted, unrestricted) after treating these subjects twice daily for 10 days. Results showed that subjects treated with 800 mg/kg of E. longifolia Jack increased orientation activities towards the receptive females (anogenital sniffing, licking and mounting), increased genital grooming towards themselves and restricted movements to a particular area of the cage but decreased interest in the external environment (climbing, raring, exploration) as compared with the controls during the investigation period. In conclusion, this study gives further evidences that different fractions of E. longifolia Jack modified the orientation activities of the middle-aged male rats.

[The medical system and its characteristics during the Koryo Dynasty period]

This article explores the medical system of the Koryo Dynasty period and its social characteristics. First, the structure of medical system and roles of medical institutions during the Koryo Dynasty period will be summarized. Then, the characteristics of the medical system will be identified through exploring the principles of its formation in a view of social recognition of medical care and a view of public policy. During the Koryo Dynasty period, medical experts were trained in national education institutions from the early days of Dynasty. After trained, they were appointed to the posts at government service with their medical profession. In the meantime, they sought ways to ascend their social position. Physicians of Oriental medicine were appointed to the posts at each local government and troops to take charge of medical treatments of the common people. Also, the state tried to assume the reins of medical system by actively taking part in circulation (collection and distribution) of herb. Taeuigam and Sangyakguk represent central medical institutions of the Koryo, taking charge of medical service for the aristocracy and the bureaucracy. The Common people were treated at DongSeoDaeBiWOn, JeWuiBo, HyeMinGuk, and YakJum in SeoKyung. However, activities of these institutions became less active around the days of military officials regime, as officers became negligent and financial base went broken. The roles of medical institutions of the Koryo government were not restricted to the treatment of diseases. Policies for the common people were constituted by two main policies, the policy for encouraging agriculture and the policy for giving relief to people. Medical institutions, with other social systems, had a social responsibility to support the governing system of the Koryo and maintain the stability of the society. In this aspect, medical institutions such as DongSeoDaeBiWon and JeWuiBo, and relief institutions such as UiChang, were all related and connected organically, and they were results of, and bases of the relief policy. However, medical system for the common people was made up first for practical needs and then improved successively. Allocation of medical experts and execution of relief work were carried out by each local government, except the case of serious disaster, which central government took part in. As the Koryo Dynasty went into its latter period, temporary institutions and one - time benefits replaced permanent institutions. These four characteristics described above were systemic characteristics of medical system during the Koryo Dynasty period.

[The Gurhigae Jejoongwon: its size and activities]

This article explores the location, size of the site, and medical activities of the Gurhigae Jejoongwon. Relevant documents such as reminiscences, diplomatic notes, newspaper accounts, maps, and photographs were referred for this study. The Gurhigae Jejoongwon located on a hill that, at present, covers the area from Ulchi-ro to MyungDong Cathedral. Its main entrance was towards Ulchi-ro. Real estate including the buildings of the Gurhigae Jejoongwon was returned to the Chosun government in 1905, and the estimated size of its site varied from 1,810 pyung to 5,036 pyung. The site of the Gurhigae Jejoongwon was 2 - 5 times larger than the 862.16-pyung-site of the Jejoongwon in its Jaedong days. With such larger size, the Jejoongwon could take care of more patients. Dr. Avison started medical education again. The Gurhigae Jejoongwon took the central part in medical treatment activities for public in Seoul, as it carried out the prevention activities against Cholera in 1895. The Chosun government highly recognized its medical treatment activities for the common people.

Should all implantable cardioverter defibrillators for ventricular arrhythmias be dual-chamber devices?

The advantages of a dual-chamber implantable cardioverter defibrillator (ICD) over a single-chamber ICD include physiologic pacing capability, atrial electrogram storage, enhanced arrhythmia discrimination algorithms, and a potential to treat atrial arrhythmia by pacing or defibrillation. Current evidence supports the supposition that dual-chamber ICDs are definitely indicated in patients who have a concomitant indication for physiologic pacing, such as bradycardia or bradycardia-dependent ventricular tachyarrhythmias. Refined dual-chamber arrhythmia discrimination algorithms and enhanced atrial therapies are probably required for patients with frequent supraventricular arrhythmias. Furthermore, in patients with systolic heart failure, low ejection fraction, and intraventricular conduction delay, triple-chamber ICDs with biventricular pacing may improve their functional status and prevent sudden arrhythmic death. Careful patient selection is required to optimize the cost-effectiveness of these sophisticated technologies.

Differences in inducibility and prognosis of in-hospital versus out-of-hospital identified nonsustained ventricular tachycardia in patients with coronary artery disease: clinical and trial design implications

OBJECTIVES

The goal of this study was to describe the influence of the clinical setting (in-hospital vs. out-of-hospital) in which nonsustained ventricular tachycardia (NSVT) is discovered on the rate of inducibility of sustained ventricular tachycardia (VT), arrhythmic events and survival in patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction.

BACKGROUND

In-hospital presentation of sustained VT is independently associated with lower long-term overall survival. The impact of the clinical setting in which NSVT is documented is unknown.

METHODS

In the Multicenter Unsustained Tachycardia Trial (MUSTT), designed to assess the benefit of randomized antiarrhythmic therapy guided by electrophysiologic testing in patients with asymptomatic NSVT, CAD and LV dysfunction, eligible patients were enrolled irrespective of the setting in which the index arrhythmia was discovered. In this retrospective analysis, we compared the rate of VT inducibility and outcome of MUSTT-enrolled patients with in-hospital versus out-of-hospital presentation of NSVT.

RESULTS

Monomorphic sustained VT was induced in 35% and 28% of the patients whose index NSVT occurred in-hospital and out-of-hospital, respectively (adjusted p = 0.006). Cardiac arrest or death due to arrhythmia at two- and five-year follow-ups were 14% and 28% for untreated patients with in-hospital-identified NSVT and 11% and 21% for the out-of-hospital group (adjusted p = 0.10). Overall mortality rates at two- and five-year follow-ups were 24% and 48% for inpatients and 18% and 38% for outpatients (adjusted p = 0.018). In patients randomized to antiarrhythmic therapy, there was no significant interaction between patient status (in-hospital vs. out-of-hospital) and treatment impact on the rates of total mortality (p = 0.98) and arrhythmic events (p = 0.08).

CONCLUSIONS

In patients with CAD and impaired LV function, asymptomatic NSVT identified in-hospital, compared with that identified out-of-hospital, is associated with a higher rate of induction of sustained VT and overall mortality. Therefore, in similar patients, the clinical setting in which NSVT is discovered should be taken into account when formulating patient risk, treatment and clinical trial design.

Using observational data to estimate prognosis: an example using a coronary artery disease registry

With the proliferation of clinical data registries and the rising expense of clinical trials, observational data sources are increasingly providing evidence for clinical decision making. These data are viewed as complementary to randomized clinical trials (RCT). While not as rigorous a methodological design, observational studies yield important information about effectiveness of treatment, as compared with the efficacy results of RCTs. In addition, these studies often have the advantage of providing longer-term follow-up, beyond that of clinical trials. Hence, they are useful for assessing and comparing patients' long-term prognosis under different treatment strategies. For patients with coronary artery disease, many observational comparisons have focused on medical therapy versus interventional procedures. In addition to the well-studied problem of treatment selection bias (which is not the focus of the present study), three significant methodological problems must be addressed in the analysis of these data: (i) designation of the therapeutic arms in the presence of early deaths, withdrawals, and treatment cross-overs; (ii) identification of an equitable starting point for attributing survival time; (iii) site to site variability in short-term mortality. This paper discusses these issues and suggests strategies to deal with them. A proposed methodology is developed, applied and evaluated on a large observational database that has long-term follow-up on nearly 10 000 patients.

Increase in B19 viral load prior to relapse of anaemia in an AIDS patient with persistent B19 infection

Anaemia caused by persistent parvovirus B19 infection can be remitted by intravenous immunoglobulin (IVIG) treatment. However, maintenance IVIG therapy is required in some AIDS patients as well as patients with combined immuno-deficiency because of relapse of anaemia. We used a simple semi-quantitative polymerase chain reaction (PCR) method to trace plasma B19 viral load after administration of IVIG. We noted that the rebound of B19 viral load occurred 6 weeks prior to detection of anaemia. This method may be helpful in determining the interval of maintenance IVIG therapy.

The human HMGB1 promoter is modulated by a silencer and an enhancer-containing intron

The highly conserved, ubiquitous high mobility group protein HMGB1 (formerly named as HMG1) is an architectural transcription factor encoded by a single functional gene in human. HMGB1 is expressed in almost all cell or tissue types studied. In general, it is expressed at a basal level in most cells but at a slightly elevated level of 2--3-fold in actively proliferating tissues or estrogen stimulated breast cancer cells. To understand the regulatory mechanism controlling expression of the human HMGB1 gene, we cloned and analyzed the upstream region as well as the first intron of this gene. We found that transcription of the human HMGB1 gene in the breast cancer MCF-7 cells starts at one major site 57 nucleotides upstream from the first exon-intron boundary. Expression of the human HMGB1 gene is under the control of a very strong TATA-less promoter, which has an activity more than 18-fold that of the SV40 promoter. Immediately upstream, a silencer element is present. This silencer can repress the activity of the HMGB1 promoter down to just one-sixth. The first intron of the human HMGB1 gene contains enhancer elements, which can increase the human HMGB1 promoter activity by 2--3-fold. We postulate that the human HMGB1 gene is capable of being expressed at a very high level. The basal level of expression observed in most cells is probably a result of the strong promoter being held in check by the silencer. The 2--3-fold increase in HMGB1 expression observed in proliferating cells or breast cancer cells stimulated by estrogen may probably result from the action of the enhancer elements in intron 1.