Clinical use of venovenous extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation has been used clinically for more than 40 years. The technique provides respiratory and/or circulatory support via venovenous and veno-arterial configurations, respectively. We review the basic physiological principles of extracorporeal membrane oxygenation systems in venovenous extracorporeal membrane oxygenation. Clinical aspects including patient selection, equipment, setup, and specific patient management are outlined. Pros and cons of the use of extracorporeal membrane oxygenation in respiratory failure are discussed.

Clinical use of venoarterial extracorporeal membrane oxygenation.

With advances in mechanical circulation, venoarterial extracorporeal membrane oxygenation has become an established technique to provide cardiopulmonary support for patients with cardiovascular collapse. This article reviews the physiological principles of such extracorporeal technique and its interaction with the native heart. Practical aspects including equipment, patient selection, and common complications with their prevention and specific management are summarised. The strategy for weaning from venoarterial extracorporeal membrane oxygenation is also discussed.

Acquired factor V inhibitor in a patient receiving venous-venous extracorporeal membrane oxygenation for Legionella pneumonia.

We report a rare complication of factor V deficiency in a patient having Legionella pneumonia. This patient also had other complications like severe acute respiratory distress syndrome, acute kidney injury, and septic shock that required venous-venous extracorporeal membrane oxygenation support. This is the first reported case of acquired factor V deficiency in a patient receiving extracorporeal membrane oxygenation for Legionella pneumonia. With the combined use of intravenous immunoglobulin, rituximab and plasma exchange, we achieved rapid clearance of the factor V inhibitor within 1 week so as to allow safe decannulation of extracorporeal membrane oxygenation.

Three-year experience of using venovenous extracorporeal membrane oxygenation for patients with severe respiratory failure.

OBJECTIVE: To present the 3-year experience of using venovenous extracorporeal membrane oxygenation for patients with severe respiratory failure in a single centre in Hong Kong. DESIGN: Case series. SETTING: A 19-bed Intensive Care Unit of a tertiary hospital in Hong Kong. PATIENTS: All patients who were managed with venovenous extracorporeal membrane oxygenation from 1 July 2010 to 30 June 2013 in the Intensive Care Unit. RESULTS: Overall, 31 patients (mean age, 42.2 years, standard deviation, 14.1 years; 21 males) received venovenous extracorporeal membrane oxygenation for the treatment of severe respiratory failure. Of these, 90.3% (28 patients) presented with pneumonia as the cause of the respiratory failure, and 22 of them had identifiable causes. A total of nine (29.0%) patients were diagnosed to have H1N1 infection. The median Murray score was 3.5 (interquartile range, 3.0-3.5); the median duration of venovenous extracorporeal membrane oxygenation support was 5.0 (2.8-8.6) days; and the median duration of mechanical ventilator support was 18.2 (7.8-27.9) days. The overall intensive care unit mortality was 19.4% (n=6). The overall in-hospital mortality and the 28-day mortality were both 22.6% (n=7). Among the 22 patients who had identifiable infective causes, those suffering from viral infection had lower intensive care unit and hospital mortality than those who had bacterial infection (8.3% vs 20.0%). All the H1N1 patients survived. Complications related to extracorporeal membrane oxygenation included severe bleeding (n=2; 6.5%) and mechanical complications of the circuits (n=3; 9.7%). CONCLUSIONS: Venovenous extracorporeal membrane oxygenation is an effective adjunctive therapy and can be used as a life-saving procedure for carefully selected patients with severe acute respiratory distress syndrome when the limits of standard therapy have been reached.

Uncommon cause of severe pneumonia: co-infection of influenza B and Streptococcus.

Influenza and pneumococcus co-infection can cause severe morbidity and mortality. Usually, this entails influenza A, while infection by influenza B is rarely serious. The literature describes influenza A epidemics leading to prolific loss of lives, notably the 1918 epidemic was blamed for the deaths of 40 to 50 million people. In this report, four patients were infected by influenza B during the influenza epidemic of 2011/12 in Hong Kong. All of them were previously healthy and had no chronic diseases; they were admitted to the hospital due to influenza-like symptoms. They rapidly deteriorated with multi-organ failure, and were subsequently diagnosed to be infected with influenza B and streptococci that gave rise to severe pneumonia. Three of them were infected with Streptococcus pneumoniae and one with Streptococcus pyogenes. All of them had leukopenia, septic shock, and acute kidney injury; two of whom died despite aggressive antibiotic treatment and organ support in the intensive care unit. According to the literature, this is the second case report of severe invasive pneumococcal pneumonia secondary to influenza B infection.

CT appearance of complications related to thoracic endovascular aortic repair (TEVAR): a pictorial essay.

Thoracic endovascular aortic repair (TEVAR) is a recognized treatment for various diseases involving the thoracic aorta. Patients treated with TEVAR require lifelong surveillance for potential complications, with CT being highly utilized in most centres. Endoleak is the most common complication and can be detected using CT. However, other complications such as stent strut perforations and end organ ischemia can also be detected on CT. The purpose of this pictorial essay is to illustrate the CT appearance of post-TEVAR complications encountered in our institution and to highlight their significance.

Determinants of chronic obstructive pulmonary disease in Chinese patients in Hong Kong.

BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) is rising in many parts of the world. This is a study of risk factors for COPD in Chinese patients in Hong Kong. DESIGN: Case-control study matched by sex and age (+/-5 years). METHODS: A total of 289 consecutive patients with COPD were recruited from out-patient clinics while healthy controls were recruited from two sources: random population and community centres for senior citizens. All patients and controls underwent a questionnaire-based interview and spirometry. RESULTS: The mean ages of COPD patients and controls were 71.1 +/- 9.4 and 67.5 +/- 9.3 years, respectively. The male to female ratio of COPD patients was 5 to 1. Smoking was found to be the most important determinant for COPD, followed by poor education and low body mass index adjusted for confounders. A dose-dependent relationship was found between the risk of COPD and pack-years smoked. Place of birth, exposure to environmental tobacco smoke and a history of asthma and tuberculosis were not associated with increased risk of COPD. CONCLUSION: Despite a progressive reduction in prevalence, smoking remains the most important predictor of COPD in Hong Kong. Greater anti-smoking efforts are warranted.

Replacement of an amino acid residue of cyclodextrin glucanotransferase of Bacillus ohbensis doubles the production of gamma-cyclodextrin.

Cyclodextrin glucanotransferase (CGTase; EC 2.4.1.19) produces cyclodextrin (CD) from starch through an intramolecular transglucosylation reaction. To obtain a better understanding of the amylolytic and cyclization mechanisms of CGTase, and furthermore to improve the production of gamma-CD, mutant CGTases were constructed by site-directed mutagenesis of the CGTase gene of Bacillus ohbensis replacing Tyr at position 188 by 19 other amino acids. All mutant enzymes retained both starch-degrading and CD synthesizing activities to various extents. Among them, a mutant enzyme having Trp instead of Tyr-188 produced 15% of gamma-CD from soluble starch, which is about twice as much as the amount produced by the wild-type enzyme.

Identification of an active principle in essential oils and hexane-soluble fractions of Curcuma xanthorrhiza Roxb. showing triglyceride-lowering action in rats.

Curcuma xanthorrhiza Roxb. (C. xanthorrhiza), known as temu lawak or Javanese turmeric, has been traditionally used in Indonesia for food and medicinal purposes. As little attention has been focused on the role of C. xanthorrhiza in lipid metabolism, the hypotriglyceridaemic activity and the active principles of the essential oil and hexane-soluble fractions prepared from C. xanthorrhiza were investigated in rats. The major component (approx. 65%) of the essential oil was identified as alpha-curcumene by capillary gas chromatography/mass spectrometry. Addition of essential oils (0.02%), prepared by steam distillation, to a purified diet resulted in a lower hepatic triglyceride concentration without influencing the serum triglyceride, whereas addition of the hexane-soluble fraction (0.5%) resulted in a lower concentration of serum as well as liver triglycerides. Rats fed the essential oil and hexane-soluble fraction had lower hepatic fatty acid synthase activity. The fraction containing alpha-curcumene, prepared from the hexane-soluble fraction by silica gel column chromatography, suppressed the synthesis of fatty acids from [14C]acetate in primary cultured rat hepatocytes. Thus, alpha-curcumene is one of the active principles exerting triglyceride-lowering activity in C. xanthorrhiza.

Fuzzy neural networks for machine maintenance in mass transit railway system.

This paper describes an application of fuzzy knowledge-based neural-network system (FKNNS) being developed by the Hong Kong Mass Transit Railway Corporation (MTRC) for the maintenance of its ticket machines in one of the busiest transit systems in the world. The model utilizes specific experts' knowledge which is transformed into fuzzy membership functions through certain control rules. The error backpropagation network was selected for the network training in which various activation functions were tested. After extensive training of the network, the FastProp with hyperbolic tangent was recommended, Input patterns were decomposed to facilitate the training process and eliminate the effect of local minima. Both the test and forecast results indicated that the FKNNS is an excellent aid for machine maintenance planning since there are too much difficulties in deriving the analytical solution otherwise. Beta test result shows a 20.08% improvement over the existing maintenance methodology. Moreover, the developed model can smoothly handle more types of industrial machine maintenance problems and generate intangible benefits toward MTRC in terms of improved customer service and better corporation image.

Synthesis and pharmacological evaluation of new topical anti-inflammatory steroids.

The purpose of this research was to develop new topical steroid derivatives showing reduced systemic effects. Pregna-16 alpha,17-carboxycyclic acetal derivatives have been recently synthesized by reacting triamcinolone with methyl acetylalkanoate in the presence of a catalytic amount of perchloric acid. In testing for the anti-inflammatory activity of the compounds, rat cotton-pellet granuloma inhibition bioassay and mouse croton-oil-induced ear oedema inhibition bioassay were employed. One of the synthesized compounds, (22R)-9 alpha-fluoro-11 beta,21-dihydroxy-3,20-dioxo-16 alpha, 17-(methyl, methoxycarbonylmethyl)methylenedioxy-1,4-pregnadiene (I), showed more or less the same activity as shown by prednisolone in the granuloma inhibition test. However, compound I showed higher activity in the ear oedema inhibition test when applied topically (ID50 = 0.002 mg), as compared to prednisolone (ID50 = 0.006 mg) and triamcinolone (ID50 = 0.026 mg). When compound I was applied to mice, and thymus involution was measured for judging systemic effects, it was found that compound I did not show any significant thymus involution up to 0.1 mg/mouse (systemic administration) and 0.5 mg/mouse (topical administration). Because of its significantly reduced systemic effects, this compound is a promising topical anti-inflammatory steroid.

Synthesis of the 7,8-dihydro-7-deazapurine derivatives and their antibiotic activity.

The cis- and trans-diastereomers of the 7,8-dihydro-7-deazapurine derivatives were synthesized from the corresponding diastereomers of 4-trans-cyano-2-methyl-3-phenyl-5-oxopyrrolidine (5), which were reduced from the 2-cis- and 2-trans-diastereomers of 4-trans-cyano-2-hydroxymethyl-3-phenyl-5-oxopyrrolidine (2) via tosylation, iodination and following elimination, respectively. The prepared cis- and trans-diastereomers of 6-amino-2-mercapto-8-methyl-7-phenyl-7,8-dihydro-7(9H)-deazapurine (8) were transferred to the corresponding 2-methylthio-diastereomers 9 and following desulfurization with Raney-nickel leaded to the cis- and trans-diastereomers of 6-amino-8-methyl-7-phenyl-7,8-dihydro-7(9H)-deazapurine (10), respectively. The synthesized 7-deazapurine derivatives were tested for their antibiotic activity by the serial two-fold dilution method.

Synthesis of (+/-)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-amines.

trans-Metanicotine, a subtype (alpha4beta2)-selective ligand for neuronal nicotinic acetylcholine receptor, is under clinical phase for Alzheimer's disease. An efficient synthetic route for (+/-)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-amines, derivatives of trans-metanicotine, was explored. Allylation reaction of aryl aldimines with allylmagnesium bromide in THF gave (+/-)-methyl-(1-aryl-but-3-enyl)-amines. Protection of the amines with the Boc group and following Heck reaction of the N-Boc amines with 3-bromopyridine gave (+/-)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-carbamic acid tert-butyl esters. Deprotection of the N-Boc group in aqueous 1N-HCI solution gave the titled amines in good yields. Thus, trans-metanicotine analogues modified at the a-position of the methylamino group with aryl groups were obtained in 5 steps.

A concise synthetic pathway for trans-metanicotine analogues.

A convenient pathway for synthesis of trans-metanicotine analogues was developed. trans-Metanicotine, a subtype (alpha4beta2)-selective ligand for neuronal nicotinic acetylcholine receptor, is under clinical phase for Alzheimer's disease. Zn-mediated allylation of allyl bromide and acetaldehyde followed by Heck reaction with 3-bromopyridine gave 5-pyridin-3-yl-pent-4-en-3-ol (2). Tosylation of 5-pyridin-3-yl-pent-4-en-3-ol followed by substitution reaction with methylamine in sealed tube gave methyl-(1-methyl-4-pyridin-3-yl-but-3-enyl)-amine (4) in good yields. Thus, trans-metanicotine analogues modified at the alpha-position of the methylamino group with various functional groups can be obtained in 4 steps.

Pharmacological activities of water extracts of Umbelliferae plants.

In order to evaluate the pharmacological activities of Chinese medicine, nine Umbelliferae plants were selected and their restoring activity against dexamethasone-induced disorders, liver protective activity, antimicrobial activity, anti-inflammatory activity and antimutagenic activity were tested and compared. Angelica dahurica. Angelica acutiloba and Ostericum koreanum showed various activities in these tests at the dose used in this study.

Large-scale mercury exposure due to a cream cosmetic: community-wide case series.

OBJECTIVE: To describe demographic characteristics, patterns of use, reported symptoms, and laboratory results associated with mercury exposure among people who used a beauty cream containing mercury. DESIGN. Descriptive study of a case series. SETTING: The Hong Kong community. PARTICIPANTS: Users of a cream cosmetic who contacted the Department of Health following a public announcement. MAIN OUTCOME MEASURES: Urine and blood mercury concentrations, cream mercury content, self-reported symptoms, duration of cream use, and duration since last cream use. RESULTS: We interviewed 314 cream users, 99% of whom were women. The mean urine and blood mercury concentrations of 286 users, who submitted a urine or blood sample, were 45.2 microg/L (reference level, <20 microg/L) and 17.1 microg/L (reference level, <10 microg/L), respectively; 65% of these participants had elevated mercury concentrations. The mercury content of the cream cosmetic ranged from 660 to 57 000 ppm. Seventy-eight percent of all cream users reported no symptoms, but absence of symptoms was not predictive of low urine and blood mercury concentrations. Urine mercury concentrations were significantly higher among people who last used the cream within 45 days. Blood mercury concentrations were elevated following cream use for as short as 2 days. CONCLUSIONS: The majority of cream users had increased urine or blood mercury concentrations but remained asymptomatic, implying that the incidence of overt symptomatic mercury poisoning resulting from dermal application of creams with mercury content lower than 57 000 ppm is low. Doctors should take a history of the use of cosmetics if patients have clinical or laboratory evidence of mercury exposure; such cases should be reported to public health authorities.

Non-O1 Vibrio cholerae septicaemia: a case report.

Non-O1 vibrio cholerae infections are associated with sporadic cases of gastroenteritis and extraintestinal infections. Septicaemia due to non-O1 vibrio cholerae is rare and are mainly reported in adults, particularly in immunocompromised patients. We report a case of non-O1 vibrio cholerae septicaemia and gastroenteritis in an 8-year-old child. The patient presented with bloody diarrhoea, fever and severe dehydration. Non-O1 vibrio cholerae were isolated from blood and stool cultures. The clinical course was uneventful after starting appropriate rehydration and supportive therapy.

[Angelicastigmin, a new eserine alkaloid from Angelica polymorpha]. / Angelicastigmin, ein neues Alkaloid vom Eserintyp aus Angelica polymorpha.

Angelicastigmine (1), which belongs to the relatively seldom group of eserine alkaloids, was isolated as new alkaloid from the roots of Angelica polymorpha Maxim. The structure was elucidated by spectroscopic methods.