Colchicine efficacy comparison at varying time points in the peri-operative period for coronary artery disease: a systematic review and meta-analysis of randomized controlled trials

Objectives

Over the years, it has been found that colchicine offers substantial benefits in secondary prevention in patients with coronary artery disease (CAD). We studied the effects of colchicine timing because there are no guidelines about when to provide it during the perioperative period for patients with CAD.

Methods

Up to January 1, 2023, seven electronic literature databases were screened (including three English databases and four Chinese databases). Randomized controlled trials included only treatment with colchicine in the perioperative period of CAD. The Cochrane Evaluation Tool was used to judge the risk of bias in research. Statistical analysis was performed by Stata 16.0 software.

Results

We evaluated twelve studies that found colchicine to be effective in decreasing the occurrence of major adverse cardiac events (MACEs) (p < 0.00001), but it also raised the rate of adverse events (p = 0.001). Subgroup analysis showed the same benefit in lowering the incidence of MACE with continuous administration of a total daily dose of 0.5 mg postoperatively while minimizing drug-related side effects in the patients (p = 0.03). When it comes to preventing surgical stroke occurrences, postoperative administration is more effective (p = 0.006). While the effect of simultaneous preoperative and postoperative administration was marginally greater than other periods in reducing postoperative hs-CRP levels (p = 0.02).

Conclusion

Colchicine, a traditional anti-inflammatory drug, also reduces the risk of MACE by reducing inflammation after PCI. Administration at different periods had no significant effect on decreasing the occurrence of MACE, but when administered postoperatively, we advise continuous administration with a total daily dose of 0.5 mg to obtain the same benefit while minimizing the drug's side effects. Postoperative administration is the better measure to prevent postoperative stroke events. Due to the effective anti-inflammatory effect of colchicine, we recommend its use as early as possible in the perioperative period and its continued use at low doses in the postoperative period.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=316751, identifier CRD42022316751.

High Performance Flexible Visible-Blind Ultraviolet Photodetectors with Two-Dimensional Electron Gas Based on Unconventional Release Strategy

Interdigitated photodetectors (IPDs) based on the two-dimensional electron gas (2DEG) at the AlGaN/GaN interface have gained prominence as high sensitivity ultraviolet (UV) PDs due to their excellent optoelectronic performance. However, most 2DEG-IPDs have been built on rigid substrates, thus limiting the use of 2DEG-IPDs in flexible and wearable applications. In this paper, we have demonstrated high performance flexible AlGaN/GaN 2DEG-IPDs using AlGaN/GaN 2DEG heterostructure membranes created from 8 in. AlGaN/GaN on insulator (AlGaN/GaNOI) substrates. The interdigitated AlGaN/GaN heterostructure has been engineered to reduce dark current by disconnecting the conductive channel at the heterostructure interface. Photocurrent has been also boosted by the escaped carriers from the 2DEG layer. Therefore, the utilization of a 2DEG layer in transferrable AlGaN/GaN heterostructure membranes offers great promises for high performance flexible 2DEG-IPDs for advanced UV detection systems that are critically important in myriad biomedical and environmental applications.

Low-grade fever during COVID-19 convalescence: A report of 3 cases

BACKGROUND

Low-grade fever during convalescence is an atypical symptom of coronavirus disease 2019 (COVID-19). Reports of such cases are rare, and the mechanism and outcome of low-grade fever during COVID-19 convalescence are not completely clear. We report 3 cases with low-grade fever during COVID-19 convalescence and highlight the main clinical, radiographic, and laboratory characteristics, thereby increasing the level of expertise in the clinical management of COVID-19 during convalescence and facilitating individualized decision-making.

CASE SUMMARY

We describe 3 patients with COVID-19, two females aged 62 and 66 years and a male 55 years, who had low-grade fever during COVID-19 convalescence. All 3 patients had no other discomfort or comorbidities during low-grade process. Lesions on computed tomography in all 3 patients had resolved during this period. Two patients tested negative on two consecutive severe acute respiratory syndrome coronavirus 2 tests with an interval of at least 24 h between tests. Body temperature in all 3 patients returned to normal after several days without treatment, and fever recurrence was not observed.

CONCLUSION

Enhancing the knowledge of low-grade fever during COVID-19 convalescence may increase the expertise in the delivery of optimal healthcare services.

Discovery of T-1101 tosylate as a first-in-class clinical candidate for Hec1/Nek2 inhibition in cancer therapy

Highly expressed in cancer 1 (Hec1) plays an essential role in mitosis and is correlated with cancer formation, progression, and survival. Phosphorylation of Hec1 by Nek2 kinase is essential for its mitotic function, thus any disruption of Hec1/Nek2 protein-protein interaction has potential for cancer therapy. We have developed T-1101 tosylate (9j tosylate, 9j formerly known as TAI-95), optimized from 4-aryl-N-pyridinylcarbonyl-2-aminothiazole of scaffold 9 by introducing various C-4' substituents to enhance potency and water solubility, as a first-in-class oral clinical candidate for Hec1 inhibition with potential for cancer therapy. T-1101 has good oral absorption, along with potent in vitro antiproliferative activity (IC₅₀: 14.8-21.5 nM). It can achieve high concentrations in Huh-7 and MDA-MB-231 tumor tissues, and showed promise in antitumor activity in mice bearing human tumor xenografts of liver cancer (Huh-7), as well as of breast cancer (BT474, MDA-MB-231, and MCF7) with oral administration. Oral co-administration of T-1101 halved the dose of sorafenib (25 mg/kg to 12.5 mg/kg) required to exhibit comparable in vivo activity towards Huh-7 xenografts. Cellular events resulting from Hec1/Nek2 inhibition with T-1101 treatment include Nek2 degradation, chromosomal misalignment, and apoptotic cell death. A combination of T-1101 with either of doxorubicin, paclitaxel, and topotecan in select cancer cells also resulted in synergistic effects. Inactivity of T-1101 on non-cancerous cells, a panel of kinases, and hERG demonstrates cancer specificity, target specificity, and cardiac safety, respectively. Subsequent salt screening showed that T-1101 tosylate has good oral AUC (62.5 μM·h), bioavailability (F = 77.4%), and thermal stability. T-1101 tosylate is currently in phase I clinical trials as an orally administered drug for cancer therapy.

Development of a loop-mediated isothermal amplification method for the rapid detection of the dioxin-degrading bacterium Ochrobactrum anthropi in soil

In this study, loop-mediated isothermal amplification (LAMP) and real-time LAMP assays were developed to detect the dioxin-degrading bacterium Ochrobactrum anthropi strain BD-1 in soil. Four primers were designed to use ITS gene amplification for the strain O. anthropi BD-1. The real-time LAMP assay was found to accomplish the reaction by 1 pg of genomic DNA load when used for nucleic acid amplification. This assay was then applied to detect O. anthropi BD-1 in eight soil samples collected from a dioxin-contaminated site. The results demonstrated that these newly developed LAMP and real-time LAMP assays will not only be useful and efficient tools for detecting the target gene, but also be used as molecular tools for monitoring the growth of dioxin-degrading O. anthropi in the soil. This is the first report to demonstrate the use of LAMP assays to monitor the presence of O. anthropi in dioxin-contaminated soil. The application of this method should improve the biomonitoring of dioxin contamination.

Clinical effects of Jiedu Xiaoyong granules in treatment of active gastric ulcer

AIM: To assess the clinical effects of Jiedu Xiaoyong granules in the treatment of active gastric ulcer (GU).

METHODS: Ninety-eight patients with active GU were randomly divided into either an experiment group or a control group. The experiment group was treated with Jiedu Xiaoyong granules, and the control group was treated with Anweiyang capsules. The traditional Chinese medicine symptom scores, the disappearance rates of yellow tongue coating and white greasy moss, the eradication rate of Helicobacter pylori (H. pylori), clinical effect and adverse reactions were compared between the two groups.

RESULTS: The scores of traditional Chinese medicine symptoms in both groups were significantly lower after treatment than before treatment (1.31 ± 1.22 vs 4.11 ± 1.42, 0.91 ± 1.19 vs 3.02 ± 1.11, 0.92 ± 1.29 vs 3.13 ± 1.06, 0.50 ± 0.71 vs 1.98 ± 0.91, 0.42 ± 0.39 vs 1.84 ± 0.69, 0.62 ± 0.60 vs 1.61 ± 0.80, 2.33 ± 1.30 vs 4.12 ± 1.40, 1.52 ± 1.38 vs 2.98 ± 1.10, 1.60 ± 0.88 vs 3.12 ± 1.08, 1.01 ± 0.69 vs 2.00 ± 0.88, 0.79 ± 0.80 vs 1.82 ± 0.80, 0.91 ± 0.79 vs 1.62 ± 0.79; P < 0.05); the decreases in the scores of traditional Chinese medicine symptoms in the experiment group were significantly higher than those in the control group (1.31 ± 1.22 vs 2.33 ± 1.30, 0.91 ± 1.19 vs 1.52 ± 1.38, 0.92 ± 1.29 vs 1.60 ± 0.88, 0.50 ± 0.71 vs 1.01 ± 0.69, 0.42 ± 0.39 vs 0.79 ± 0.80, 0.62 ± 0.60 vs 0.91 ± 0.79; P < 0.05). The disappearance rates of yellow tongue coating and white greasy moss as well as the eradication rate of H. pylori in the experiment group were significantly higher than those in the control group (77.55% vs 42.86%, 65.31% vs 38.78%; P < 0.05). The recovery rate and total effective rate in the experiment group were also significantly higher than those in the control group (67.35% vs 34.69%, 97.96% vs 75.51%; P < 0.05).

CONCLUSION: Jiedu Xiaoyong granules can improve Chinese medicine symptoms and tongue image in patients with active GU, and is associated with a high eradication rate of H. pylori, distinct clinical effects, and very few adverse reactions.

Discovery of 4-aryl-N-arylcarbonyl-2-aminothiazoles as Hec1/Nek2 inhibitors. Part I: optimization of in vitro potencies and pharmacokinetic properties

A series of 4-aryl-N-arylcarbonyl-2-aminothiazoles of scaffold 4 was designed and synthesized as Hec1/Nek2 inhibitors. Structural optimization of 4 led to compound 32 bearing C-4' 4-methoxyphenoxy and 4-(o-fluoropyridyl)carbonyl groups that showed low nanomolar in vitro antiproliferative activity (IC50: 16.3-42.7 nM), high intravenous AUC (64.9 μM·h, 2.0 mg/kg) in SD rats, and significant in vivo antitumor activity (T/C = 32%, 20 mg/kg, IV) in mice bearing human MDA-MB-231 xenografts. Cell responses resulting from Hec1/Nek2 inhibition were observed in cells treated with 32, including a reduced level of Hec1 coimmunoprecipitated with Nek2, degradation of Nek2, mitotic abnormalities, and apoptosis. Compound 32 showed selectivity toward cancer cells over normal phenotype cells and was inactive in a [(3)H]astemizole competitive binding assay for hERG liability screening. Therefore, 32 is as a good lead toward the discovery of a preclinical candidate targeting Hec1/Nek2 interaction.

Langerhans Cell Histiocytosis in an Adult - a rare, life-threatening and not to be missed

Langerhans Cell Histiocytosis (LCH) is an uncommon neoplastic disorder characterized by accumulation of histiocytes in various tissues. The clinical manifestation is highly variable, ranging from an isolated skin rash or a single bony lesion, to fatal multi-organ failure. Due to its rarity and systemic involvement, the epidemiology of LCH is still not fully understood and most studies focus on the paediatric population. The extent of clinical involvement has important prognostic implications. Treatment options may be local or systemic depending on disease extent. Here we describe a rare case of adult onset LCH who presented with recurrent pneumothoraces, diabetes insipidus and papules and plaques over the scalp and forehead.

Decoupling free-carriers contributions from oxygen-vacancy and cation-substitution in extrinsic conducting oxides

The intrinsic oxygen-vacancies and the extrinsic dopants are two major fundamental free-carrier sources for the extrinsic conducting oxides, such as Sn-doped In(2)O(3). Yet, the individual contributions of the above two free-carrier sources to the total carrier concentrations have never been unraveled. A carrier-concentration separation model is derived in this work, which can define the individual contributions to the total carrier concentration from the intrinsic oxygen-vacancies and the extrinsic dopants, separately. The individual contributions obtained from the present carrier-concentration separation model are verified by the two-state trapping model, photoluminescence, and positron annihilation lifetime (PAL) spectroscopy. In addition, the oxygen-vacancy formation energy of the Sn:In(2)O(3) thin film is determined to be 0.25 eV by PAL spectroscopy.

Public awareness of hepatitis B infection: a population-based telephone survey in Hong Kong

OBJECTIVE

To test our hypothesis that there is inadequate knowledge and awareness of hepatitis B infection among the general population in Hong Kong.

DESIGN

A random telephone survey using a structured multiple-choice questionnaire.

SETTING

Hong Kong community.

PARTICIPANTS

Hong Kong residents aged 18 years or above.

RESULTS

A total of 506 respondents were successfully interviewed in February 2010. Approximately half of respondents (55%) were aware that hepatitis B virus is the most common cause of chronic viral hepatitis in Hong Kong. Regarding knowledge about the mode of transmission, mother-to-infant transmission and blood contact were recognised as risk factors by 67% and 65% of respondents, respectively. Transmission by sexual contact, sharing a razor or toothbrush, and tattooing or body piercing were appreciated by 44%, 41%, and 37% of respondents, respectively. A majority (73%) had the mistaken belief that the virus is transmitted by eating contaminated seafood. Over half of respondents (53%) knew nothing about the clinical presentation of acute hepatitis B. Only 35% of respondents realised that periodic abdominal ultrasonographic examinations are indicated for asymptomatic hepatitis B carriers. While 51% of respondents reported being tested for hepatitis B virus infection, only 36% acknowledged being vaccinated against the infection. Education level, occupation, and marital status were factors associated with both hepatitis B virus screening and vaccination.

CONCLUSION

These findings support our hypothesis that there is inadequate knowledge and awareness about hepatitis B infection in the general population in Hong Kong.

Carbon balance of anaerobic granulation process: carbon credit

The concept of carbon credit arose out of increasing awareness of the need to reduce emissions of greenhouse gases to combat global warming which was formalized in the Kyoto protocol. In addition to contribution to sustainable development with energy recovery in the form of methane, carbon credits can be claimed by application of advanced anaerobic processes in wastewater treatment for reducing emissions of greenhouse gases. As anaerobic granular systems are capable of handling high organic loadings concomitant with high strength wastewater and short hydraulic retention time, they could render much more carbon credits than other conventional anaerobic systems. This study investigated the potential carbon credit derived from laboratory-scale upflow anaerobic sludge blanket (UASB) reactors based on a carbon balance analysis. Methane emission reduction could be calculated by calculating the difference of UASB reactors and open lagoon treatment systems. Based on the 2.5l bench-scale reactor, the total CH(4) emissions reduction was calculated as 29 kg CO(2)/year. On scaling up to a typical full-scale anaerobic digester, the total CH(4) emissions reduction could achieve 46,420 tons CO(2) reduction/year. The estimated carbon credits would amount to 278,500 US$ per year by assuming a carbon price of 6 US$ per metric ton CO(2) reduction. The analysis postulated that it is financially viable to invest in advanced anaerobic granular treatment system from the revenue generated from carbon credits.

Nanoparticles in wastewater from a science-based industrial park - coagulation using polyaluminum chloride

The Hsinchu Science-based Industrial Park (HSIP) is the hi-tech manufacturing hub of Taiwan. Wastewater from the HSIP contains numerous nano-sized silicate particles whose size distributions peak at 2 and 90 nm. A 3-5 mg l(-1) as Al dose of polyaluminum chloride (PACl) was used in the field to coagulate these particles, but the removal efficiency was low. Laboratory scale tests indicated that although PACl coagulation removed 52% of the turbidity and 48% of the chemical oxygen demand (COD) from water, its effect on nano-particle removal was minimal. About 58% of the soluble COD was associated with colloidal Si particles. A light scattering test and transmission electron microscopy (TEM) demonstrated that the nano-particles agglomerated in approximately linear aggregates of sizes 100-300 nm. Prolonged contact between residual PACl and the nano-particles generated large aggregates with sizes of up to 10 microm and a fractal dimension of 2.24-2.63. The results presented herein should be of interest in the processing of "high-tech" wastewater that contains nanosized silica particles.

Effects of aeration intensity on formation of phenol-fed aerobic granules and extracellular polymeric substances

Effect of air aeration intensities on granule formation and extracellular polymeric substances content in three identical sequential batch reactors were investigated. The excitation-emission-matrix spectra and multiple staining and confocal laser scanning microscope revealed proteins, polysaccharides, lipids, and humic substances in the sludge and granule samples. Seed sludge flocs were compacted at low aeration rate, with produced extracellular polymeric substances of 50.2-76.7 mg g(-1) of proteins, 50.2-77.3 mg g(-1) carbohydrates and 74 mg g(-1) humic substances. High aeration rate accelerated formation of 1.0-1.5 mm granules with smooth outer surface. The corresponding quantities of extracellular polymeric substances were 309-537 mg g(-1) of proteins, 61-109 mg g(-1) carbohydrates, 49-92 mg g(-1) humic substances, and 49-68 mg g(-1) lipids. Intermediate aeration rate produced 3.0-3.5 mm granules with surface filaments. Reactor failure occurred with overgrowth of filaments, probably owing to the deficiency of nutrient in liquid phase. No correlation was noted between extracellular polymeric substances composition and the proliferation of filamentous microorganisms on granule surface.

Spreading dynamics and dynamic contact angle of non-Newtonian fluids

The spreading dynamics of power-law fluids, both shear-thinning and shear-thickening fluids, that completely or partially wet solid substrate was investigated theoretically and experimentally. An evolution equation for liquid-film thickness was derived using a lubrication approximation, from which the dynamic contact angle versus the contact line moving velocity relationship was evaluated. In the capillary spreading regime, film thickness h is proportional to xi3/(n+2) (xi is the distance from the contact line), whereas in the gravitational regime, h is proportional to xi1/(n+2), relating to the rheological power exponent n. The derived model fit the experimental data well for a shear-thinning fluid (0.2% w/w xanthan solution) or a shear-thickening fluid (7.5% w/w 10 nm silica in polypropylene glycol) on a completely wetted substrate. The derived model was extended using Hoffmann's proposal for partially wetting fluids. Good agreement was also attained between model predictions and the shear-thinning fluid (1% w/w cmc solution) and shear-thickening fluid (10% w/w 15 nm silica) on partially wetted surfaces.

Membrane biofouling by extracellular polymeric substances or soluble microbial products from membrane bioreactor sludge

This study extracted the soluble microbial products and loosely bound and tightly bound extracellular polymeric substances (EPS) from suspended sludge from a membrane bioreactor, original and aerobically/anaerobically digested, and compared their fouling potentials on a microfiltration membrane. The resistance of cake layer accounts for 95-98% of the total filtration resistances when filtering the whole sludges, with anaerobically digested sludge presenting the highest resistance among the three tested sludges. The tightly bound EPS has the highest potential to foul the membrane; however, the loosely bound EPS contribute most of the filtration resistances of the whole sludges. The foulants corresponding to the irreversible fouling have chemical fingerprints similar to those from loosely bound EPS, which have a greater predilection to proteins and humic substances than to polysaccharides.

Oxygen diffusion and consumption in active aerobic granules of heterogeneous structure

The interior structure of aerobic granules is highly heterogeneous, hence, affecting the transport and reaction processes in the granules. The granule structure and the dissolved oxygen profiles were probed at the same granule in the current work for possible estimation of transport and kinetic parameters in the granule. With the tested granules fed by phenol or acetate as carbon source, most inflow oxygen was consumed by an active layer thickness of less than 125 microm on the granule surface. The confocal laser scanning microscopy scans also revealed a surface layer thickness of approximately 100 microm consisting of cells. The diffusivities of oxygen transport and the kinetic constant of oxygen consumption in the active layers only were evaluated. The theoretical models adopted in literature that ignored the contributions of the layered structure of aerobic granule could have overlooked the possible limitations on oxygen transport.

Oxygen diffusion in active layer of aerobic granule with step change in surrounding oxygen levels

High biomass density and large size limit the transfer of dissolved oxygen (DO) in aerobic granules. In the literature, the oxygen diffusivity is often employed as an input parameter for modeling transport processes in aerobic granules. The interior of an aerobic granule was observed to be highly heterogeneous. In this work, the distributions of extracellular polymeric substances (EPS) and cells in the interior of phenol-fed and acetate-fed granules were built up using a five-fold staining scheme, combined with the use of a confocal laser scanning microscope (CLSM). The steady-state and transient DO with step changes in surrounding DO levels at various depths were measured in the granules using microelectrodes. Cells were probed in a surface layer of thickness 125-375 microm. A marked fall in DO was also noted over this surface layer. No aerobic oxidation could occur beneath the active layer, indicating the oxygen transfer limit. Fitting the steady-state and transient DO data over the active surface layer yielded apparent diffusivities of oxygen were (9.5+/-3.5)x10(-10)m(2)s(-1) for the phenol-fed granule and (3.5+/-1.0)x10(-10)m(2)s(-1) for the phenol-fed granule. These values were lower than those adopted in models in the literature.

Fluorecent staining for study of extracellular polymeric substances in membrane biofouling layers

Membrane biofouling by microbial products adversely impacts the feasibility of adopting membrane bioreactors (MBRs) for treating wastewater. The fouling layer structure determines the pressure drop across the fouling layer. Three-dimensional distributions of nucleic acids, proteins, alpha-D-GLUCOPYRANOSE POLYSACCHARIDES, AND B-D-glucopyranose polysaccharides in the fouling layer formed on a mixed cellulose ester membrane were generated utilizing a quadruple staining protocol combined with confocal laser scanning microscopy (CLSM). For the first time, this study constructed a three-dimensional volumetric grids model representing the fouling layer structure on the basis of a series of CLSM images. Quantitative structural information about the fouling layer was extracted from the CLSM images.

Non-traumatic colon perforation in children: a 10-year review

Colon perforation is an abdominal surgical emergency in the pediatric population, but is seldom reported when occurring from non-traumatic causes in children beyond the neonate. The goal of this study was to identify the clinical characteristics, management, and outcomes of non-traumatic colon perforation in children. Medical records for the 10-year period from September 1994 to September 2004 were reviewed for children beyond the neonate with non-traumatic colon perforation. Data gathered included age, gender, symptoms, duration of symptoms, physical findings, and length of postoperative hospital stay. Diagnostic information included laboratory data, radiographic imaging, and operative findings. Forty-four patients with non-traumatic colon perforation were recruited into this study. The mean age was 2.22 +/- 1.87 years; 91.4% of cases were younger than 5 years old. The most common presenting symptom was fever (97.7%); the most common sign was abdominal distention (93.1%). The mean duration of symptoms prior to admission was 6.19 days. Pneumoperitoneum was presented in 86.3% of patients by plain abdominal radiograph. Ascending and transverse colon were the most common perforation sites. Non-typhoid salmonella was the leading pathogen isolated, causing 20.4% of episodes. One case died due to Clostridium speticum infection. Non-traumatic colon perforation most commonly affects children younger than 5 years of age. It may be secondary to infection, especially non-typhoid salmonella. Plain abdominal radiograph can be an adjuvant tool for the high index of suspicion for colon perforation in children with abdominal distention and history of fever or diarrhea for more than 5 days.

A CFD study of the deep bed filtration mechanism for submicron/nano-particle suspension

The mechanism of the deep bed filtration for submicron and nano particles suspension was conducted by means of a force analysis on the suspended particles flow path through order-packed granular filter beds. The flow fields through the filter beds were calculated by using the commercial available CFD software--Fluent. Various types of granular packing structures, such as the simple cubic packing, body-centered packing and face-centered packing structures were chosen for analysis. The motion of suspended particle of 2.967, 0.816, 0.460 and 0.050 microm in diameter, respectively, were tracked by considering the following forces including a net gravitational force, hydraulic drag force, lift force, Brownian force, van der Waals force and a double layer force. The effects of the granular bed packing structure, the porosity of these beds and the suspended particle diameter on the capture efficiency of a granular filter bed were examined. The force analysis depicts that the inertial effect and van der Waals force increased the capture probability of particles on the granular filter bed while the lift force and the Brownian force decreased the particle deposition. Simulated results show that among the chosen packing structures, the face-center packed granular bed gives the greatest pressure drop and capture efficiency of particles due to the lower packing porosity. The simple cubic packed filter bed showed the lowest pressure drop and capture efficiency of particles due to the greatest packing porosity among the chosen packing structures. It is mainly due to the simple cubic packing structure in which there exists the free vertical downward flowing path and thus exhibits a higher packing porosity. The comparisons of the simulated capture efficiency with experimental results depicted that the body-centre packed granular bed showed the best approximation of capture efficiency compared to that of the randomly packed granular bed.

Co-conditioning and dewatering of alum sludge and waste activated sludge

Co-conditioning and dewatering behaviors of alum sludge and waste activated sludge were investigated. Two different sludges were mixed at various ratios (2:1; 1:1; 1:2; 1:4) for study. Capillary suction time (CST) and specific resistance to filtration (SRF) were utilized to assess sludge dewaterability. Relatively speaking, waste activated sludge, though of higher solid content, was more difficult to be dewatered than alum sludge. It was found that sludge dewaterability and settlability became better with increasing fraction of alum sludge in the mixed sludge. Dosage required of the cationic polyelectrolyte (KP-201C) for dewatering was reduced as well. It is proposed that alum sludge acts as skeleton builder in the mixed sludge, and renders the mixed sludge more incompressible which is beneficial for sludge dewatering. Implications of the results of the study to the sludge management plan for Taipei City that generates both alum sludge and waste activated sludge at significant amount are also discussed. The current sludge treatment and disposal plan in Metropolitan Taipei could be made more cost-effective.

Anterior esthetic crown-lengthening surgery: a case report

The theoretical concepts underlying crown-lengthening surgery are reviewed, and a patient who underwent esthetic crown-lengthening surgery is described. An overview of the various indications and contraindications is presented.

Biliary tract disease and acute non-A-E hepatitis in Hong Kong: prospective study

OBJECTIVE

To investigate the role of biliary tract disease in patients with acute non-A-E hepatitis.

DESIGN

Prospective study.

SETTING

Infectious diseases unit, government hospital, Hong Kong.

PATIENTS

Sixty-one consecutive patients, admitted with the diagnosis of acute hepatitis and negative hepatitis serology for hepatitis A, B, C, D, and E virus.

MAIN OUTCOME MEASURES

Abdominal ultrasound and endoscopic retrograde cholangiopancreatography findings; clinical outcome.

RESULTS

Ultrasonographic abnormalities indicating biliary tract disease were found in 30% (18/61) of patients. Endoscopic retrograde cholangiopancreatography performed in 78% (14/18) of patients with abnormal ultrasound finding(s) confirmed the presence of biliary tract disease. Age, sex, serum alanine aminotransferase level, and serum albumin level were independent predictors of biliary tract disease in the patients studied.

CONCLUSION

Biliary tract diseases were found in 20% of patients with acute non-A-E hepatitis. Serum amylase and abdominal ultrasonography should be performed for all patients presenting with acute non-A-E hepatitis. Endoscopic retrograde cholangiopancreatography is indicated for those with apparent gallstones or abnormal biliary tract findings.

Transport properties of ionic drugs in the ammonio methacrylate copolymer membranes

PURPOSE

Ammonio methacrylate copolymer is a pharmaceutical excipient widely used as a coating material for encapsulation of pellet and tablet dosage forms. Because of the charged ammonio function groups within the polymer, ionic drugs may interact with the coating film while transporting through it. The kinetic swelling and drug permeation properties of the ammonio methacrylate copolymer membranes were studied to delineate the effect of ionic interaction between the ionic drugs and the membranes.

METHODS

The pH and ionic strength of the solutions and the charged properties of drugs were varied to study the effects on the transport properties through the membranes. Ambroxol was chosen as a model cationic drug and aspirin as a model anionic drug.

RESULTS

The degree of membrane swelling in the drug-free solution decreases as the ionic strength increases but it is irrelevant to the pH. With the presence of ionic drugs, the degree of membrane swelling is affected by the drug species as well as the pH of the solutions in addition to the effect of ionic strength. The degree of swelling for a membrane in a solution containing aspirin is higher at a lower pH and ambroxol is lower at a lower pH. Aspirin experiences a three-stage permeation and ambroxol a two-stage one. The ion-exchange reaction between the anionic carboxylic groups in aspirin and the cationic ammonio groups in the membranes results in a slow permeation stage during the transient state. The pseudo steady-state permeability for each drug follows the trend as the degree of membrane swelling in the drug media at various pH and ionic strengths. However, it is much higher for aspirin than ambroxol although the degree of membrane swelling is higher in an ambroxol solution than that in an aspirin solution. The permeability of ambroxol through the membrane is largely reduced because of the Donnan exclusion effect.

CONCLUSIONS

The interaction between ionic drugs with the cationic groups in the membranes affects the ionic strength of the solutions and results in a pH-dependent degree of swelling. The ionic interaction also determines the drug permeation rates as well as the transient permeation behaviors.

Extracellular polymers of ozonized waste activated sludge

Effect of ozonation on characteristics of waste activated sludge was investigated in the current study. Concentrations of cell-bound extracellular polymers (washed ECPs) did not change much upon ozonation, whereas the sum of cell-bound and soluble extracellular polymers (unwashed ECPs) increased with increasing ozone dose. Washed ECPs in original sludge as divided by molecular weight distribution was 39% < 1,000 Da (low MW), 30% from 1,000 to 10,000 Da (medium MW), and 31% > 10,000 Da (high MW). It was observed that the low-MW fraction decreased, and the high-MW fraction increased in ozonized sludge. The unwashed ECPs were characterized as 44% in low MW, 30% in medium MW, and 26% in high MW. Both low-MW and medium-MW fractions of unwashed ECPs decreased while high-MW fraction increased in ozonized sludge. The dewaterability of ozonized sludge, assessed by capillary suction time (CST) and specific resistance to filtration (SRF), deteriorated with ozone dose. The optimal dose of cationic polyelectrolyte increased with increasing ozone dose. The production rate and the accumulated amount of methane gas of ozonized sludge were also higher.

Plesiomonas shigelloides infection in Hong Kong: retrospective study of 167 laboratory-confirmed cases

OBJECTIVE

To study the epidemiological, clinical, and microbiological features of Plesiomonas shigelloides infection in Hong Kong.

DESIGN

Retrospective study.

SETTING

Infectious Disease Unit of a district hospital, Hong Kong.

PATIENTS

Patients with laboratory-confirmed cases of Plesiomonas shigelloides infection between 1 January 1995 and 31 December 1998.

MAIN OUTCOME MEASURES

Epidemiological and clinical data, antibiotic sensitivity, and clinical outcome.

RESULTS

There was an increasing trend in the number of isolates of Plesiomonas shigelloides obtained and the prevalence of the bacterium. A total of 197 isolates were obtained from 188 patients, and most isolates (172; 87.3%) were obtained during the summer. Clinical and epidemiological data were available for 167 patients (85 males, 82 females). Patient age ranged from 1 month to 95 years; the mean and median ages of the patients older than 15 years were 51.0 and 40.5 years, respectively (n=132). Only 35 (21.0%) of the 167 patients had a history of travel outside Hong Kong, whereas 21 (12.6%) had a history of consuming seafood or uncooked food; 39 (23.4%) had underlying medical conditions. Most patients (165; 98.8%) had symptoms of Plesiomonas shigelloides infection. Nine (5.4%) patients had had chronic diarrhoea for more than 2 weeks; watery and bloody diarrhoea was discharged by 122 (73.1%) and 42 (25.1%) of the patients, respectively. All 197 Plesiomonas shigelloides isolates were sensitive to ofloxacin, or levofloxacin and ceftriaxone. Resistance or partial resistance was recorded for ampicillin (72%), tetracycline (67%), co-trimoxazole (12%), and chloramphenicol (5%). The majority of patients (142/167; 85.0%) had self-limiting cases of infection, but 25 patients were given antibiotics for more severe symptoms at the time of presentation; there were two deaths.

CONCLUSIONS

The occurrence of Plesiomonas shigelloides infection in Hong Kong is increasing, although most cases of are self-limiting.

Diagnostic pitfalls in congenital right diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare disease of newborns. Right-sided diaphragmatic hernia is even rarer. The clinical and radiological presentations, which are well documented in left-sided diaphragmatic hernia, are variable in right-sided diaphragmatic hernia. This makes the diagnosis of right-sided diaphragmatic hernia more difficult. During a 12-year period, seven cases of right-sided diaphragmatic hernia were collected from a single institution. Their presentations and clinical courses have been reviewed. Low prenatal diagnostic rate, various roentgenogram expressions after birth, and absence of specific clinical presentations were noted. These expressions may become pitfalls in diagnosis and lead to inappropriate treatment. From our experience in these 7 cases and a brief literature review, we try to emphasize the characteristics and the diagnostic pitfalls of this disease. In conclusion, right-sided congenital diaphragmatic hernia has a variable clinical spectrum with high mortality and morbidity. Careful evaluation of the clinical presentations, ultrasonography and chest films is mandatory for precise diagnosis.

Sequence and molecular analysis of the rpoA cluster genes from Xanthomonas campestris pv. campestris

The Xanthomonas campestris rpsM (S13)-rpsK (S11)-rpsD (S4)-rpoA (alpha)-rplQ (L17) cluster, encoding RNA polymerase alpha-subunit and four ribosomal proteins, reside in a 3164-bp DNA region. The N-terminal sequence of the authentic alpha-protein determined chemically matches that predicted from the nucleotide sequence. rplQ is monocistronic, instead of being co-transcribed with the other genes as in Escherichia coli. Antiserum against the His-tagged alpha-protein cross-reacted with the E. coli alpha-protein.

Helicobacter treatment with quadruple therapy in primary health care for patients with a history of ulcer disease

BACKGROUND

Few patients with a history of peptic ulcer are treated by their GP for H. pylori infection, even though theoretical evidence supports such an approach.

OBJECTIVES

We aimed to determine the validity of this recommendation and to test the feasibility of quadruple therapy in primary health care.

METHODS

In this prospective, non-randomized intervention study, 51 unselected patients with a history of proven ulcer disease received a 7-day quadruple therapy (lansoprazole, colloidal bismuth subcitrate, tetracycline and metronidazole) from their GP. Main outcome measures were: (i) endoscopically confirmed cure of the infection; (ii) results of serology at entry and at 6 months follow-up; (iii) quality of life at entry, at 6 weeks and at 6 months follow-up; (iv) gastric symptoms at entry, at 6 weeks and at 6 months follow-up; and (v) medication at entry and at 6 months follow-up.

RESULTS

Quadruple therapy was well tolerated and there were no drop-outs with this regimen. Intention to treat cure rate was 48/51 (94%, 95% CI 87-100%), per protocol cure rate was 48/49 (98%, 95% CI 94-100%). 45/50 (90%) had positive serology at entry. IgG antibody titres decreased > 40% in 95.2% of patients. Quality of life improved significantly after treatment, gastric symptoms decreased and medication use decreased.

CONCLUSIONS

GPs should be encouraged to identify patients with a history of ulcer disease and chronic use of acid suppressants and offer them treatment for H. pylori infection. This approach will cure the infection in almost all patients, it will improve the quality of life and decrease costs. Quadruple therapy does not lose efficacy when employed in primary care. Pre-treatment serological testing is potentially useful for narrowing down the treatment group to those with actual infection, and serology is promising as an easy and cheap follow-up instrument in primary health care.

Neonatal necrotizing fasciitis: a report of three cases and review of the literature

OBJECTIVE

Necrotizing fasciitis (NF) is a predominantly adult disorder, with bacterial infection of the soft tissue. In children, it is relatively rare and has a fulminant course with a high mortality rate. In the neonate, most cases of NF are attributable to secondary infection of omphalitis, balanitis, mammitis, postoperative complications, and fetal monitoring. The objective of this communication is to report 3 cases of neonatal NF and provide a literature review of this disorder.

RESULTS

This review yielded 66 cases of neonatal NF. Only 3 cases were premature. There was no sex predilection and the condition rarely recurred. Several underlying conditions were identified that might have contributed to the development of neonatal NF. These included omphalitis in 47, mammitis in 5, balanitis in 4, fetal scalp monitoring in 2, necrotizing enterocolitis, immunodeficiency, bullous impetigo, and maternal mastitis in 1 patient each. The most common site of the initial involvement was the abdominal wall (n = 53), followed by the thorax (n = 7), back (n = 2), scalp (n = 2), and extremity (n = 2). The initial skin presentation ranged from minimal rash to erythema, edema, induration or cellulitis. The lesions subsequently spread rapidly. The overlying skin might later develop a violaceous discoloration, peau d'orange appearance, bullae, or necrosis. Crepitus was uncommon. Fever and tachycardia were frequent but not uniformly present. The leukocyte count of the peripheral blood was usually elevated with a shift to the left. Thrombocytopenia was noted in half of the cases. Hypocalcemia was rarely reported. Of the 53 wound cultures available for bacteriologic evaluation, 39 were polymicrobial, 13 were monomicrobial, and 1 was sterile. Blood culture was positive in only 20 cases (50%). Treatment modalities included the use of antibiotics, supportive care, surgical debridement, and drainage of the affected fascial planes. Two of the 6 cases who received hyperbaric oxygen therapy died. The overall mortality rate was 59% (39/66). In 12 cases, skin grafting was required because of poor granulation formation or large postoperative skin defects among the survivors.

CONCLUSION

Neonatal NF is an uncommon but often fatal bacterial infection of the skin, subcutaneous fat, superficial fascia, and deep fascia. It is characterized by marked tissue edema, rapid spread of inflammation, and signs of systemic toxicity. The wound cultures are predominantly polymicrobial and the location of initial involvement depends on the underlying etiologic factor. High index of suspicion, prompt aggressive surgery, appropriate antibiotics, and supportive care are the mainstays of management in the newborn infant with NF.

Prompt recognition of necrotizing fasciitis in a newborn

We report a 13-day-old female neonate with necrotizing fasciitis, who presented with fever and erythema on her back. Rapidly progressive extension of the erythema to the abdominal wall occurred within 12 hours. Sonography for the lesion showed extensive fascial thickening with fluid accumulation. An abscess was also demonstrated. Necrotizing fasciitis was highly suspected. Under sonographic guidance, pus was aspirated from the abscess. A smear for the aspirated pus revealed a large number of neutrophils and abundant gram-positive cocci. Immediate surgical debridement was done. Cultures from the pus and blood revealed Staphylococcus aureus. The patient was free of symptoms after surgical debridement and aggressive antibiotic therapy. She had skin grafting to reconstruct the debrided wound on the 20th hospital day and was discharged shortly after the debridement of wound.

Acute encephalitis complicating rubella

During an epidemic of rubella in Hong Kong between October 1996 and June 1997, four male patients presented with rubella complicated by encephalitis, the symptoms of which started 1 to 5 days after the appearance of the rash characteristic of rubella. Two patients recovered completely within 1 week and one complained of a slight impairment of short-term memory. Severe cerebral oedema, and herniation across the brainstem and cerebellum developed in the fourth patient, who died 15 days later. The presence of serum immunoglobulin M antibody against rubella virus was demonstrated in all four patients; one patient also had immunoglobulin M antibody against rubella virus in his cerebrospinal fluid. No virus could be isolated during post-mortem examination of the fourth patient.

The labrum of the calcaneocuboid joint

The authors describe a previously unreported anatomical structure in the calcaneocuboid joint of the foot and discuss the clinical significance. Fibroadipose synovial folds or labra are present in different locations throughout the calcaneocuboid joint of the foot. They appear to be wedge-shaped infections attached to the joint capsule in areas of incongruent joint spaces. Their surface is covered with synovial cells with a highly vascular loose connective tissue sublayer. Nerve fibers were seen in association with the joint capsule, but not within the V-shaped labrum. The clinical significance of the presence of the labrum is discussed, but their function is uncertain. These structures can project up to half the joint distance and have the possibility of producing impingement syndromes, or even tears. Since they are covered with two to three layers of synoviocytes, they also have the ability to produce a synovitis. The labrum can be identified using MRI, and once their presence is known arthroscopic repair of these structures is theoretically possible.

Haemolysis complicating acute viral hepatitis in patients with normal or deficient glucose-6-phosphate dehydrogenase activity

Haemolytic anaemia as a complication of acute hepatitis has been reported in up to 23% of patients. However, the incidence may rise up to 70-87% in patients who have glucose-6-phosphate dehydrogenase (G6PD) deficiency. Massive intravascular haemolysis with renal failure, hepatic encephalopathy and even death have been reported. In our retrospective study of patients with acute viral hepatitis, the overall incidence of acute haemolysis was 4% (17/434). Only 53% (9/17) of them had G6PD deficiency. Patients with acute haemolysis had a significantly higher peak bilirubin level and required more prolonged hospitalization. Since hepatitis A virus vaccination, unlike hepatitis B virus vaccination, is not yet recommended for routine immunization, we suggest subjects who are G6PD-deficient should be vaccinated against hepatitis A. In endemic areas of hepatitis A virus infection, universal immunization remains the definitive answer.

Application of asymmetric TPX membranes to transdermal delivery of nitroglycerin

In this study, asymmetric poly(4-methyl-1-pentene) (TPX) membranes, fabricated by the dry/wet inversion method, were applied to transdermal delivery of nitroglycerin (NTG), a drug for treating angina pectoris. The flux of NTG through the TPX membrane was measured in vitro by a Franz cell. The results indicate that the NTG flux through asymmetric TPX membranes is strongly dependent on the membrane structure, which can be varied by adding nonsolvents in the casting solution. By adding different kinds of nonsolvents and adjusting the added amounts, membranes with different NTG release rates can be fabricated. It was also found that, with suitable drug formula, the NTG dissolution rate of a prototype TPX patch is comparable to that of a commercial patch, Transderm-Nitro. In addition, the data of NTG flux through a composite of TPX membrane and pig skin are also presented.

Structure-activity analysis of the interaction of curacin A, the potent colchicine site antimitotic agent, with tubulin and effects of analogs on the growth of MCF-7 breast cancer cells

Originally purified as a major lipid component of a strain of the cyanobacterium Lyngbya majuscula isolated in Curaçao, curacin A is a potent inhibitor of cell growth and mitosis, binding rapidly and tightly at the colchicine site of tubulin. Because its molecular structure differs so greatly from that of colchicine and other colchicine site inhibitors, we prepared a series of curacin A analogs to determine the important structural features of the molecule. These modifications include reduction and E-to-Z transitions of the olefinic bonds in the 14-carbon side chain of the molecule; disruption of and configurational changes in the cyclopropyl moiety; disruption, oxidation, and configurational reversal in the thiazoline moiety; configurational reversal and substituent modifications at C13; and demethylation at C10. Inhibitory effects on tubulin assembly, the binding of colchicine to tubulin, and the growth of MCF-7 human breast carcinoma cells were examined. The most important portions of curacin A required for its interaction with tubulin seem to be the thiazoline ring and the side chain at least through C4, the portion of the side chain including the C9-C10 olefinic bond, and the C10 methyl group. Only two modifications totally eliminated the tubulin-drug interaction. The inactive compounds were a segment containing most of the side chain, including its two substituents, and analogs in which the methyl group at the C13 oxygen atom was replaced by a benzoate residue. Antiproliferative activity comparable with that observed with curacin A was only reproduced in compounds that were potent inhibitors of the binding of colchicine to tubulin. Molecular modeling and quantitative structure-activity relationship studies demonstrated that most active analogs overlapped extensively with curacin A but failed to provide an explanation for the apparent structural analogy between curacin A and colchicine.

Acute viral hepatitis in Hong Kong: a study of recent incidences

Acute hepatitis patients admitted to a referral centre from January 1995 through December 1995 were studied to determine the seroprevalence of the hepatitis viruses and related risk factors. Of the 434 patients with acute viral hepatitis, the episodes due to hepatitis A, B, C, D, and non-A, non-B, non-C, (non-ABC) were 214 (49.3%), 163 (37.6%), 7 (1.6%), 0 (0%), and 50 (11.5%), respectively. Acute hepatitis A and non-ABC hepatitis commonly occur in late spring and early summer and are probably related to the intake of shellfish and travel to endemic areas. Approximately 60% of cases of symptomatic hepatitis B infection were acute exacerbations of chronic infection. Sexual exposure was the single most important risk factor for acute hepatitis B infection. The rarity of acute hepatitis C and D might be related to the low rate of intravenous drug use in our locality. Hepatitis E virus probably contributed significantly to the cases of non-ABC hepatitis. Further studies are needed to establish the importance of various causative agents of acute hepatitis in Hong Kong.

Plasmodium infection unmasked by corticosteroid therapy

In the past four years, we have encountered three patients in whom malaria parasites were found incidentally in their blood when they were receiving corticosteroid therapy. Although there is little direct evidence that corticosteroid therapy can activate human malaria, animal studies have successfully demonstrated the recrudescence effect of immunosuppression on malaria infection.

Composite poly(2-hydroxyethyl methacrylate) membranes as rate-controlling barriers for transdermal applications

Composite membranes were prepared by casting a linear poly(2-hydroxyethyl methacrylate) (pHEMA) solution onto polyester non-woven supports, and then the supported pHEMA within the membranes was cross-linked by a diisocyanate cross-linking agent to form a network structure. The swelling and permeation properties of these membranes were evaluated, with a system of nitroglycerin and aqueous ethanol solution, for potential application in transdermal drug delivery. The degree of swelling of these membranes in water and aqueous ethanol decreases as the cross-linker content is increased and increases slightly with an increase in the original molecular weight of the linear pHEMA. The permeation rates of both nitroglycerin and ethanol increase as the cross-linker content is reduced, the polymer molecular weight increases, and the concentration of the casting solution or membrane thickness decreases. Depending on the preparation conditions, the membranes can be tailored to give a permeation flux ranging from 4 to 68 micrograms cm-2 h-1 for nitroglycerin.

Hapatitis A and E in Hong Kong

Acute viral hepatitis is one of the most prevalent infectious diseases in Hong Kong and hepatitis A accounts for two thirds or more of reported cases. Improved sanitation has led to a decline in hepatitis A infection in childhood but more clinically overt adult cases now occur. Shellfish ingestion and recent travel are important risk factors. A highly immunogenic and effective inactivated hepatitis A vaccine is available. Hepatitis E is of emerging importance as a cause of acute hepatitis. Large outbreaks have occurred in China and other developing countries; sporadic cases occur in Hong Kong. High mortality is associated with hepatitis E complicating late pregnancy. Serological diagnosis by enzyme immunoassay for anti-HEV is available. The education of travellers to endemic areas is advised with special caution being given to pregnant women. A vaccine for hepatitis E is not yet available.

Experience with distal circular myotomy for long-gap esophageal atresia

From 1980 to 1994, the authors treated 65 cases of esophageal atresia (with or without tracheoesophageal fistula). Among these patients, 15 (23%) underwent pure proximal circular myotomies and five (8%) underwent both proximal and distal circular myotomies. Of the latter five cases, three were Gross type C and two were Gross type A. The gap ranged from 4.5 cm to 6.5 cm (mean, 5 cm). Surgical complications in these five patients included two anastomotic leaks (40%), one anastomotic stricture (20%), and four gastroesophageal refluxes (80%). Three patients eventually underwent fundoplication as an antireflux procedure. Mucosal outpouching was noted in all cases. The myotomy did not adversely affect the esophageal peristalsis and motility on the esophagogram. Esophageal function was similar to that of other children who had esophageal atresia without myotomy. All patients could eat food typical for their age. This limited experience suggests that distal circular myotomy might be a safe adjuvant procedure to achieve primary anastomosis in long-gap esophageal atresia.

Effectiveness of quadruple therapy using lansoprazole, instead of omeprazole, in curing Helicobacter pylori infection

BACKGROUND

Omeprazole enhances the efficacy of bismuth-based triple therapy. It is unknown whether the same is true for other proton pump inhibitors. Lansoprazole has superior anti-Helicobacter activity in vitro and possibly also in vivo; therefore we investigated quadruple therapy with lansoprazole.

MATERIALS AND METHODS

In two studies performed in separate hospitals, a total of 67 Helicobacter pylori-positive patients were treated with 7-day quadruple therapy (lansoprazole, colloidal bismuth subcitrate, tetracycline, and metronidazole) after 3 days of lansoprazole pretreatment. Testing for cure was done by endoscopy in study 1 and by breath test in study 2.

RESULTS

Cure rates per protocol were 31 of 31 (100%) in study 1 and 30 of 32 (94%) in study 2. Intention-to-treat cure rates were 31 of 35 (89%) in study 1 and 30 of 32 (94%) in study 2. Cured overall were 32 of 34 with a metronidazole sensitive strain and 3 of 3 with a metronidazole-resistant strain. Data on side effects were collected from 51 patients. Twelve (21%) had no side effects, 27 (53%) had mild side effects, 10 (20%) had moderate side effects, but only 2 (4%) had severe side effects. Side effects, never were the reason that a patient stopped taking the medication.

CONCLUSIONS

The results with lansoprazole-quadruple therapy are comparable to the historic control group treated with omeprazole-quadruple therapy. The cure rare is very high, and although mild to moderate side effects occurred in many patients, everybody finished the treatment regime.

Long-term follow-up after cure of Helicobacter pylori infection with 4 days of quadruple therapy

BACKGROUND

We have shown that 4 days of quadruple therapy after omeprazole pre-treatment is an effective therapy for curing H. pylori infection. In this study we investigated whether this regimen would maintain the high cure rate during long-term follow-up. Some recent studies have reported high recurrence rates after apparent cure. Apparently not all methods to test for cure have sufficient sensitivity to pick up small numbers of residual bacteria. This study also served to investigate whether our methods to test for cure 5-6 weeks post-treatment were reliable.

METHODS

All patients from a previous study were invited to return for a 14C-urea breath test and serology. A representative group of 37 patients (76%) returned for a urea breath test and serology. The mean follow-up was 14.7 months (range 11.4-23.6 months).

RESULTS

None of the 37 patients had a positive urea breath test results. IgG antibody titres fell steadily in all patients, showing a mean decrease of 83% at the end of the follow-up. None of the patients showed an increase in titre. Reinfection was therefore 0% (0 of 37).

CONCLUSION

Four days of quadruple therapy seems to be an effective therapy for the eradication of H. pylori as evidenced after long-term follow-up. Our biopsy methodology is reliable in identifying treatment failures 5-6 weeks post-treatment.

Resurgence of cholera in Hong Kong

Cholera is one of the three diseases subject to the International Health Regulations. After a period of over 30 years, the seventh pandemic of cholera, which started in South East Asia in 1961, still shows no sign of a decline. On the contrary, it has increased its severity and invaded many other countries in Africa and Latin America. In the last two years, there has been a recrudescence of the disease in South East Asia and Western Pacific Regions. The discovery of a new strain of Vibrio cholerae 0139 in these regions is causing concern in view of its potential to cause major epidemics and higher mortality. Hong Kong had two intensive outbreaks of cholera in the last two years. The cause of these outbreaks was not clear, but adverse environmental conditions and increasing pollution of coastal waters have been implicated. The spread of cholera knows no geographical boundaries. There is a need for intensified efforts among health authorities in the affected areas to prevent the international spread of the disease.

The melanotropic peptide, [Nle4,D-Phe7] alpha-MSH, stimulates human melanoma tyrosinase activity and inhibits cell proliferation

Seventeen human melanoma cell (HMC) lines, both melanotic and amelanotic, were incubated in the continuous presence of a potent melanotropic peptide hormone analog, [Nle4,D-Phe7] alpha-MSH, for 72 hr with daily changes of medium. Only one cell line (HD, melanotic) consistently responded to the hormone analog by increased tyrosinase activity. Three (one melanotic, two amelanotic) of the HMC lines also failed to respond to the peptide by either increased or decreased enzyme activity when incubated continuously in the presence of the peptide for longer periods of time (6,15,27,43 days). The HD cell line, however, again responded with increasingly enhanced basal enzyme activity the longer the cells were incubated in the presence of the melanotropin. One amelanotic cell line (C8161) responded with enhanced enzyme activity when grown to confluency in the continuous presence of the peptide. Basal tyrosinase activity of the C8161 cell line may have increased as cell density in the flasks increased. These results suggest that under conditions of increased cell number, phenotypic expression of tyrosinase activity in so called "amelanotic" (tyrosinase-negative) cells is increased and can be enhanced further by stimulation with a melanotropic peptide. Under conditions of increased cell number, the presence of [Nle4,D-Phe7] alpha-MSH caused morphological differentiation (shape change); the cells became enlarged and very dendritic. The number of cells in monolayer (surface of the flask) and in the medium were drastically reduced in both melanotic and "amelanotic" cell lines incubated with [Nle4,D-Phe7] alpha-MSH. The data support other published reports that melanotropic peptides inhibit human melanoma cell growth (proliferation) in vitro, most likely through a cytostatic mechanism. [Nle4,D-Phe7] alpha-MSH also exhibited a prolonged (residual) inhibitory action on HD cell proliferation. In other words, inhibition of cell growth (proliferation) of the HMCs was evident even several days after removal of the melanotropic peptide from the incubation medium.

Polyvinyl alcohol plasma deposited nylon 4 membrane for hemodialysis

Polyvinyl alcohol (PVA) is a hydrophilic and blood compatible material, but it is easily hydrolyzed in aqueous solution. Various methods, including chemical crosslinking and gamma-ray irradiation, have been investigated by many researchers for overcoming the instability of PVA in aqueous solution. This study suggests a new hemodialysis membrane, which is prepared by plasma depositing vinylacetate (VAc) onto annealled nylon 4 membrane, followed by hydrolysis treatment. This improves the blood compatibility of nylon 4 and overcomes the hydrolysis problem of PVA. In addition to conventional plasma deposition, the plasma initiated interpenetrating network (IPN) method is also investigated. The new hemodialysis membranes prepared by both conventional plasma deposited VAc onto nylon 4 (PPVA/N4) and IPN polymer of plasma initiated VAc onto nylon 4 (PIPVA/N4 IPN) show significant improvement in blood compatibility. However, the solute permeabilities of PIPVA/N4 IPN membranes are higher than those of PPVA/N4 membranes. The permeabilities of NaCl, vitamin B12, and albumin for membranes prepared by IPN at 80 W, 30 sec plasma deposited conditions, i.e., the optimized conditions, are 3.614, 0.070, and 0.000 x 10(-5) cm2/min, respectively. The mole ratio of adsorbed fibrinogen to adsorbed albumin (the mole ratio F/A) for this membrane is 0.20, and it also shows excellent blood compatibility in this study.

Does hepatitis C virus infection contribute to hepatocellular carcinoma in Hong Kong?

BACKGROUND

Hong Kong has a high incidence of hepatocellular carcinoma (HCC) and, because it is an endemic area for hepatitis B virus (HBV) infection, the etiologic association between HCC and HBV infection is reported to be as high as 80%. Hepatitis C virus (HCV) recently was shown to be a possible pathogenetic agent for HCC in a number of countries.

METHODS

To assess the relative importance of these two viruses in HCC in Hong Kong, a retrospective study of 424 Chinese patients with HCC was performed.

RESULTS

Three hundred forty-one (80.3%) patients were found to be carriers of hepatitis B surface antigen (HBsAg). Hepatitis C antibodies (anti-HCV) were detected in 31 patients (7.3%). Fifteen patients with positive findings for anti-HCV had concurrent HBV infection, 11 had serologic evidence of previous HBV infection, and only 5 patients had anti-HCV marker alone. Patients with positive findings for anti-HCV were older than those with HBsAg (mean ages, 60 and 53 years, respectively). A higher preponderance of male patients was found in the HBsAg-positive group; the male to female ratio was 11:1, compared with 7:1 among patients with anti-HCV. Anti-HCV was detected in 0.64% of 175 age-matched and sex-matched controls.

CONCLUSIONS

These data indicate a possible causal role of HCV infection in HCC, but it is of relatively minor epidemiologic significance in Hong Kong, where HBV infection is overwhelming.