4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone is correlated with 8-hydroxy-2'-deoxyguanosine in humans after exposure to environmental tobacco smoke

Cigarette smoking and exposure to environmental tobacco smoke (ETS) are important risk factors for many cancers. However, exposure doses have usually not been quantitatively assessed in human studies. In humans 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronate conjugate (defined as total NNAL) are the major metabolites of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, a cigarette-specific carcinogen. Although animal studies have shown that exposure to cigarette smoke increases tissue oxidative DNA damage, the relationship between cigarette smoke and 8-hydroxydeoxyguanosine (8-OHdG) is not consistent in human studies. In the present study, we have developed a simple, sensitive, and robust LC-MS/MS method for quantifying total NNAL and 8-OHdG concentrations in human plasma. We quantified total NNAL and 8-OHdG in plasma as well as 8-OHdG in urine of 121 healthy male subjects. Total NNAL levels were significantly higher in ever-smokers than in never-smokers. Furthermore, total NNAL levels in plasma were increased with numbers of cigarettes smoked per day in ever-smokers. It suggests that total NNAL in plasma is a good biomarker for cigarette smoke exposure. After stratifying by smoking status and adjusting for age, ETS exposure and occupation category, total NNAL was associated with plasma and urinary 8-OHdG in never-smokers, but not in ever-smokers. Since total NNAL levels in nonsmokers represented the ETS exposure, it appears that 8-OHdG levels are dose-dependently correlated with their ETS exposure dose. Furthermore, this correlation supports the hypothesis that oxidative DNA damage is one of major adverse effects induced by ETS exposure in humans.

Relationship between cumulative dose of thiazolidinediones and clinical outcomes in type 2 diabetic patients with history of heart failure: a population-based cohort study in Taiwan

BACKGROUND

Thiazolidinediones (TZDs) are widely used antidiabetic agents, but there is great concern and conflicting reports over their possible effect on cardiovascular morbidity, especially in patients with heart failure (HF).

METHODS

Using 2000-2005 Taiwan's National Health Insurance (NHI) claims data, this population-based, retrospective cohort study investigated if there was an association between the cumulative TZD dose and clinical outcomes in type 2 diabetic patients recently hospitalized for HF. Study outcomes were death, first all-cause readmission, and first readmission for HF. Cox proportional hazard models were used to analyze the association between TZD versus sulfonylurea (SU) use and these outcomes.

RESULTS

Out of a total of 8139 eligible patients, 224 were taking TZD (65.63% female; mean [SD] age, 68.30[10.60] years) and 7915 were taking SU (55.10% female; 70.30[10.50] years). Patients taking TZD were at higher risk for readmission for HF (59 cases; HR 1.58 (95% confidence interval, 95%CI 1.44-1.72)), all-cause readmission (147 cases; 1.40 (1.30-1.70)), and death (103 cases; 2.23 (1.58-3.14)). The higher the cumulative exposure to TZD, the greater the risk of HF readmission, all-cause readmission, and death.

CONCLUSION

Among diabetic patients who had been hospitalized for HF, TZD users were at significantly greater risk for readmission for HF, all-cause readmission, and death than SU users. The risk of all adverse clinical outcomes appeared to highly relate to cumulative exposure to TZD. These findings provide empirical evidence supporting the latest black box warnings issued by the United States Food and Drug Administration in August, 2007 advising that TZD not be prescribed for diabetic patients with symptomatic heart failure.

Cardiovascular and gastrointestinal events of three antiplatelet therapies: clopidogrel, clopidogrel plus proton-pump inhibitors, and aspirin plus proton-pump inhibitors in patients with previous gastrointestinal bleeding

BACKGROUND

Concomitant use of antiplatelet agents and proton-pump inhibitors (PPIs) has been recommended in patients with a history of gastrointestinal (GI) hemorrhage. However, recent studies have reported that PPIs may alter clopidogrel's pharmacokinetics and potentially lead to an increased risk of recurrent adverse cardiovascular (CV) events.

METHODS

Using Taiwan's 2000-2006 National Health Insurance database, this population-based retrospective cohort study assessed CV and GI events in patients who had a prior history of GI bleeding and had been prescribed ongoing antiplatelet therapy after acute coronary syndrome (ACS) discharge. We identified 3,580 ACS patients and categorized them into (1) those taking clopidogrel alone, (2) those taking clopidogrel plus PPIs, and (3) those taking aspirin plus PPIs. Cox proportional hazards models were used to assess the association between the use of antiplatelet therapies and CV/GI events.

RESULTS

The clopidogrel only group and the clopidogrel plus PPI group were found to be at lower risk for GI events than the aspirin plus PPI group [adjusted hazard ratio (HR) 0.23 (95% confidence interval; CI 0.14-0.36) and HR 0.70 (0.52-0.96), respectively]. However, while the clopidogrel only group had a lower risk of CV events than the aspirin plus PPI group [HR 0.57 (0.38-0.84)], the clopidogrel plus PPI group had a significantly higher CV risk than the aspirin plus PPI group [HR 1.59 (1.18-2.13)].

CONCLUSIONS

Our findings suggest that although the use of clopidogrel plus PPIs provides GI benefits, with this treatment, there is an increased CV risk among patients with a history of GI bleeding.

The potentially inappropriate prescription of new drug: thiazolidinediones for patients with type II diabetes in Taiwan

PURPOSE

To examine the potentially inappropriate prescription of thiazolidinediones (TZD).

METHODS

Data on TZD prescriptions were collected from Taiwan's National Health Insurance dataset from 2001 to 2006. TZDs were considered inappropriately prescribed when they were prescribed to patients who were (1) under 18 years old, (2) pregnant, who had (3) type 1 diabetes, (4) severe heart failure, (5) hepatic insufficiency, or (6) renal insufficiency and taking TZD + metformin in combination. We aggregated potentially inappropriate prescriptions of TZD for each health-care institution in each month starting from March 2001, when TZD was introduced to Taiwan's market.

RESULTS

The potentially inappropriate prescription of TZD increased from 9.41% in 2001 to 12.50% in 2006. Prior inappropriate prescription led to a 0.06% (95%CI: 0.04-0.08) further increase in its later inappropriate prescription. Accumulated months of experience prescribing TZD was found associated with higher proportion of inappropriate prescription of TZD (0.03%, 95%CI: 0.01-0.05). However, it was negatively associated with new incidence of inappropriate prescription of TZD (-0.20, 95%CI: -0.22 to -0.18). The greater the volume of prior TZD prescription (-0.87%, 95%CI: -0.93 to -0.81) and the greater the number of accumulated months since adoption (-0.14%, 95%CI: -0.16 to -0.12), the greater the decrease in rates of new inappropriate prescriptions.

CONCLUSIONS

Along with the quick penetration of the new DM drug came an increased possibility that it would be prescribed inappropriately, a trend that persisted over time.

Leonurine improves ischemia-induced myocardial injury through antioxidative activity

The present study was designed to investigate the protective effects of 4-guanidino-n-butyl syringate (leonurine), a compound in Herba Leonuri (HL) on ischemic rat heart to determine the protective mechanisms associated with ischemic rat hearts. Rat heart ischemia was induced by ligation of the left coronary artery. Creatine kinase (CK) and lactate dehydrogenase (LDH) in plasma and superoxide dismutase (SOD) activity in heart homogenates were measured. We found leonurine significantly decreased levels of LDH and CK activities in plasma. This observation corresponded with decreased infarct size of ischemic rat heart induced by ligation of the left coronary artery. Moreover, the mRNA expression of the pro-apoptotic gene Bax was significantly down-regulated by 0.68-fold (p < 0.05) and the anti-apoptotic gene Bcl-2 was up-regulated by 1.41-fold (p < 0.05) in the leonurine treated groups as compared with acute myocardium ischemia (MI) controls measured by RT-PCR. Correspondingly, Bcl-2 and Bax protein levels detected by Western blotting coincided with gene expression levels. In addition, the mRNA expression level of the antioxidant enzyme Mn-SOD was significantly increased 1.23-fold (p < 0.05) and this finding corresponded with an observed increase in SOD activity and also with a committed decrease in lipid peroxidation. Taken together, our results demonstrated that leonurine attenuated myocardium injury during MI via antioxidative and anti-apoptotic effects and leonurine might become a useful adjuvant cardioprotective agent.

Pharmaceutical penetration of new drug and pharmaceutical market structure in Taiwan: hospital-level prescription of thiazolidinediones for diabetes

This study used Taiwan's National Health Insurance claim database (years 2000-2005) to examine how thiazolidinediones (TZD), a new class of drugs for diabetes, penetrated into Taiwan's hospitals, and its association with the concentration of all diabetes drugs at the hospital level. We collected 72 monthly summaries of diabetes prescriptions from all hospitals in Taiwan. Hospital-level pharmaceutical concentration was measured by penetration of TZD, defined as monthly market share of TZD in each hospital. Concentration of diabetes drugs was measured by Herfindahl-Hirschman indices. We found a negative association (coefficient = -0.3610) between TZD penetration and concentration of diabetes drug but a positive association between penetration of TZD and the volume of prescribed diabetes drugs (coefficient = 0.4088). In conclusion, hospital characteristics and volume of services determined the concentration of pharmaceuticals at the institution level, reflecting the heterogeneous competition between pharmaceutical companies within each hospital. Institution-level pharmaceutical concentration influences the adoption and penetration of new drugs.

ISO-1, a macrophage migration inhibitory factor antagonist, inhibits airway remodeling in a murine model of chronic asthma

Airway remodeling is the process of airway structural change that occurs in patients with asthma in response to persistent inflammation and leads to increasing disease severity. Drugs that decrease this persistent inflammation play a crucial role in managing asthma episodes. Mice sensitized (by intraperitoneal administration) and then challenged (by inhalation) with ovalbumin (OVA) develop an extensive eosinophilic inflammatory response, goblet cell hyperplasia, collagen deposition, airway smooth muscle thickening, and airway wall area increase, similar to pathologies observed in human asthma. We used OVA-sensitized/challenged mice as a murine model of chronic allergic airway inflammation with subepithelial fibrosis (i.e., asthma). In this OVA mouse model, mRNA and protein of macrophage migration inhibitory factor (MIF) are upregulated, a response similar to what has been observed in the pathogenesis of acute inflammation in human asthma. We hypothesized that MIF induces transforming growth factor-β1 (TGF-β1) synthesis, which has been shown to play an important role in asthma and airway remodeling. To explore the role of MIF in the development of airway remodeling, we evaluated the effects of an MIF small-molecule antagonist, (S,R)3-(4-hy-droxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), on pathologies associated with the airway-remodeling process in the OVA mouse model. We found that administration of ISO-1 significantly mitigated all symptoms caused by OVA treatment. In addition, the treatment of OVA-sensitized mice with the MIF antagonist ISO-1 significantly reduced TGF-β1 mRNA levels in pulmonary tissue and its protein level in bronchial alveolar lavage fluid supernatants. We believe the repression of MIF in the ISO-1 treatment group led to the significant suppression observed in the inflammatory responses associated with the allergen-induced lung inflammation and fibrosis in our murine asthma (OVA) model. Our results implicate a possible function of MIF in the pathogenesis of chronic asthma and suggest that MIF might be an important therapeutic target for airway remodeling.

[Effects of dexamethasone on intracellular expression of Th17 cytokine interleukin 17 in asthmatic mice]

OBJECTIVE

To study the effects of dexamethasone on intracellular expression of Th17 cytokine interleukin 17 and the mechanisms in asthmatic mice.

METHODS

Experimental asthma was induced by ovalbumin (OVA) sensitization in 20 in female Balb/c mice with (dexamethasone group, n=10) or without dexamethasone treatment (model group, n=10), with another 10 serving as the control group. The levels of IL-17 in the bronchoalveolar lavage fluid (BALF) and serum of the mice were measured by enzyme-linked immunosorbent assay (ELISA), and the airway inflammation was evaluated by HE staining. The expressions of IL-17 and RORgammat mRNA were measured by reverse transcription-polymerase chain reaction (RT-PCR), and the expression of RORgammat protein was measured by immunohistochemical staining.

RESULTS

The levels of RORgammat and IL-17 mRNA and protein in the asthmatic model group were significantly higher than those in the control group (P<0.01), and the increased expressions of RORgammat and IL-17 mRNA and protein in the asthmatic mice were significantly reduced by dexamethasone treatment (P<0.05).

CONCLUSION

Dexamethasone can inhibit the release of IL-17 probably by inhibiting RORgammat expression and blocking Th17 differentiation in asthmatic mice.

The relationship between influenza vaccination and outpatient visits for upper respiratory infection by the elderly in Taiwan

OBJECTIVE

To evaluate the effect of influenza vaccination on the reduction of the risk of outpatient visits for upper respiratory infection (URI) among the elderly in Taiwan.

METHODS

The data for this observational study, consisting of 1729 people aged 65 years or older, were drawn from Taiwan's 2001 National Health Interview Survey. This survey data was then linked with National Health Insurance claim data for December 2001 to November 2002. Survival analysis of Cox proportional hazards model was performed to examine the risk of URI outpatient visits in elderly people vaccinated with the influenza vaccine and those not vaccinated during a year-long study period since the influenza season began. To adjust for potential self-selection bias, we used propensity score method to categorize individuals into two groups, based on the predicted probability of being vaccinated from a logistic regression of spatial random effect. Propensity score group 1 (PSG 1) were those with a predicted probability of being vaccinated lower than 0.5, and PSG 2 were those with a predicted probability of being vaccinated of 0.5 or higher.

RESULTS

The overall vaccination rate was 50%. Logistic regression showed the probability of being vaccinated was related to the number of outpatient visits for URI before the influenza season began (odds ratio (OR) 1.07; 95% confidence interval (CI) 1.04-1.10). Our first survival analysis showed that being vaccinated significantly reduced the risk of URI outpatient visits in PSG 2 during the 1-year study period (hazard ratio 0.89; 95% CI 0.81-0.97). Separate survival analysis showed that being vaccinated reduced the risk of URI outpatient visits for both PSG groups during the first 3 months of the study period.

CONCLUSION

Being vaccinated could reduce the risk of outpatient visits for URI among the elderly during the influenza season.

The effect of changing reimbursement policies on quality of in-patient care, from fee-for-service to prospective payment

OBJECTIVE

Using insurance claims for hemorrhoidectomies, we examined the effect of Taiwan's Bureau of National Health Insurance's case payment system, a fixed case payment rate method used to reimburse health care providers for in-patient care.

DESIGN

This observational natural experimental study examined changes in medical care that occurred between two phases: the 9 months before case payment system was implemented on 1 October 1997 and the 9 months afterwards. The changes were analyzed by performing linear regressions with interaction between hospital type and the implementation of case payment system.

SETTING

This study was based on total claim data from National Health Insurance.

STUDY PARTICIPANTS

A total of 23 638 hemorrhoidectomy insurance claims.

MAIN OUTCOME MEASURES

Length of stay, number of medical services, and number of drug prescriptions. Medical services were stratified into those that were considered minimal requirements and those considered optional by the Bureau of National Health Insurance.

RESULTS

Over the 18-month period, the number of patients increased by 23.7%. After the case payment system was implemented, length of stay decreased by 0.59 days (P < 0.0001), the number of minimally required services increased by 2.19 to 4.24 items (P < 0.0001), the number of optional service items decreased by 0.32 items (P < 0.0001), and drug prescription decreased slightly by 0.58 to 0.99 items (P < 0.0001) per hospitalization.

CONCLUSIONS

The case payment system successfully shortened length of stay without significantly sacrificing the provision of services.

The effect of Taiwan's tax-induced increases in cigarette prices on brand-switching and the consumption of cigarettes

The effect of raising cigarette taxes to reduce smoking has been the subject of several studies, which often treat the price of cigarettes as an exogenous factor given to smokers who respond to it by adjusting their smoking behavior. However, cigarette prices vary with brand and quality, and smokers can and do switch to lower-priced brands to reduce the impact of the tax on the cost of cigarettes as they try to consume the same number of cigarettes as they had before a tax hike. Using data from a two-year follow-up interview survey conducted before and after a new cigarette tax scheme was imposed in Taiwan in 2002, this study examines three behavioral changes smokers may make to respond to tax-induced cigarette price increase: brand-switching, amount consumed, and amount spent on smoking. These changes were studied in relation to smoker income, before-tax cigarette price, level of addiction, exposure to advertizing, and consumer loyalty. We found that smokers, depending upon exposure to advertizing, level of consumer loyalty and initial price of cigarettes, switched brands to maintain current smoking habits and control costs. We also found that the initial amount smoked and level of addiction, not price, at least not at the current levels in Taiwan, determined whether a smoker reduced the number of cigarettes he consumed.

Signals in the activation of opioid mu-receptors by loperamide to enhance glucose uptake into cultured C2C12 cells

In an attempt to understand the signal pathways of opioid mu-receptors for glucose metabolism, we used loperamide to investigate the glucose uptake into the myoblast C2C12 cells. Loperamide enhanced the uptake of radioactive deoxyglucose into C2C12 cells in a concentration-dependent manner that was abolished in cells pre-incubated with naloxone or naloxonazine at concentrations sufficient to block opioid mu-receptors. Pharmacological inhibition of phospholipase C (PLC) by U73122 resulted in a concentration-dependent decrease in loperamide-stimulated uptake of radioactive deoxyglucose into C2C12 cells. This inhibition of glucose uptake by U73122 was specific since the inactive congener, U73343, failed to modify loperamide-stimulated glucose uptake. Moreover, both chelerythrine and GF 109203X diminished the action of loperamide at concentrations sufficient to inhibit protein kinase C (PKC). The obtained data suggest that an activation of opioid mu-receptors in C2C12 cells by loperamide may increase glucose uptake via the PLC-PKC pathway.

Public opinion regarding earmarked cigarette tax in Taiwan

BACKGROUND

Cigarette taxation has been perceived by academics and policy-makers as one of the most effective ways of reducing the use of cigarettes. On January 1 2002, the Taiwan government imposed a New Taiwan (NT) 5 dollars per pack tax earmarked for the purpose of tobacco control. This study uses a survey collected prior to taxation to assess public attitudes toward cigarette taxation, public beliefs about the effectiveness of cigarette taxation at reducing cigarette use and public opinions about the allocation of this tax revenue.

METHODS

Data were drawn from a national face-to-face interview on cigarette consumption in 2000. A total of 3,279 adults were aged 18 to 64 years; 49.9% of whom were male and 50.1% female, and with a smoking prevalence of 49.1% and 4.1%, respectively. The attitudes toward cigarette tax were analysed using multi-logit regressions. We analysed by logistic regression the potential changes in smoking behaviour that smokers might make in response to the five NT (New Taiwan) dollar earmarked tax on cigarettes per pack. We summarized public opinions about the allocation of earmarked tax revenue using descriptive statistics.

RESULTS

Current smokers (OR = 0.34) and former smokers (OR = 0.68) were less likely to support the cigarette tax than non-smokers. A favourable attitude toward the tax was positively associated with personal monthly income, especially among females. Among male smokers, the possibility of reducing/quitting smoking in response to the five-NT-dollar tax was negatively associated with the monthly expense for smoking. The two most frequently-suggested areas to receive money from the revenue collected from the earmarked tax were health education and cancer subsidy.

CONCLUSIONS

Smoking status and economic factors determine the attitude and potential responses of people toward the cigarette tax. Taiwan's five NT-dollar earmarked tax for cigarettes may have only a limited effect upon the reduction in cigarette use.

The clinical diagnosis of chronic acalculous cholecystitis

BACKGROUND

Chronic acalculous cholecystitis (CAC), a diagnosis of exclusion, appears to be more common than was previously thought. We correlated the pathology with test results and response to treatment in a prospective study to obtain data for evidence-based management.

METHODS

The study subjects were patients with chronic biliary symptoms but had normal sonogram results. They were further investigated with esophagogastroduodenoscopy, multidiscipline evaluations, and cholecystokinin-stimulated scintigraphy (CCK-HIDA). They were offered laparoscopic cholecystectomy (LC) when the symptoms were intransigent, and the main abnormality was a low ejection fraction (EF) as determined by CCK-HIDA. We analyzed the histologic findings of the gallbladder, CCK-HIDA EF, and clinical outcomes during the control period with a concurrent series of LC for calculus from the same surgeons.

RESULTS

Of 176 cholecystectomies for biliary pain without stones, 152 had pathologically verified CAC. EF by CCK-HIDA was low in patients with CAC (18%) and low in normal gallbladders (26%). In the same period, 497 patients had cholecystectomies for cholelithiasis. Lasting symptom relief for CAC after LC was not different from that for calculous disease (85% vs 90%).

CONCLUSIONS

The syndrome consisting of chronic biliary symptoms, stone-free sonograms, low EF in CCK-HIDA, and absence of other pain sources is highly predictive for CAC, which is well treated with LC, with results similar to those for calculous disease.

Complete genome analysis of enterovirus 71 isolated from an outbreak in Taiwan and rapid identification of enterovirus 71 and coxsackievirus A16 by RT-PCR

Hand, foot, and mouth disease (HFMD) and encephalomyelitis were two major clinical manifestations during the 1998 enterovirus 71 (EV71) epidemic in Taiwan. To investigate whether different clinical patterns were caused by alterations in EV71 genomes, the complete nucleotide sequences of four EV71 strains associated with HFMD or encephalomyelitis were compared. Among these viral strains, two or three nucleotide differences were found within the 5'-noncoding region, and two or four amino acid differences were found within the regions encoding viral polyproteins; however, none of these differences were correlated with either clinical manifestation. Because coxsackievirus A16 was another major causative agent of HFMD, a reverse transcription-polymerase chain reaction assay, with high sensitivity and specificity for identification of EV71 (both 100%) and coxsackievirus A16 (100 and 98.8%), was developed for the rapid differential identification of these two viruses in HFMD patients.

In vitro modified release of acyclovir from ethyl cellulose microspheres

The aim of this study was to demonstrate a sustained-release microparticulate dosage form for acyclovir via an in vitro study. Ethyl cellulose was selected as a model encapsulation material. All of the microspheres were prepared by an oil-in-water solvent evaporation technique. A 2(3) full factorial experiment was applied to study the effects of the viscosity of polymer, polymer/drug ratio, and polymer concentration on the drug encapsulation efficiency and the dissolution characteristics. The encapsulation efficiency of acyclovir in microspheres was in the range of 20.0-56.6%. Increase in the viscosity of ethyl cellulose and the ratio of CH2Cl2/ethyl cellulose increased drug encapsulation efficiency. The drug continuously released from microspheres for at least 12 h, and the release rate depended on the pH of the release medium. The sustained release characteristic was more prominent in the simulated intestine fluid than in the simulated gastric fluid. A faster release of drug was observed when a high viscosity polymer was used. The decomposition of acyclovir significantly decreased when encapsulated by ethyl cellulose, especially when stored at 37 and 50 degrees C.

Antibacterial activity of leaf essential oils and their constituents from Cinnamomum osmophloeum

The antibacterial activities of the essential oils from leaves of two Cinnamomum osmophloeum clones (A and B) and their chemical constituents were investigated in this study. The nine strains of bacteria, including Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Salmonella sp., and Vibrio parahemolyticus, were used in the antibacterial tests. Results from the antibacterial tests demonstrated that the indigenous cinnamon B leaf essential oils had an excellent inhibitory effect. The MICs (minimum inhibitory concentrations) of the B leaf oil were 500 microg/ml against both K. pneumoniae and Salmonella sp. and 250 microg/ml against the other seven strains of bacteria. Cinnamaldehyde possessed the strongest antibacterial activity compared to the other constituents of the essential oils. The MICs of cinnamaldehyde against the E. coli, P. aeruginosa, E. faecalis, S. aureus, S. epidermidis, MRSA, K. pneumoniae, Salmonella sp., and V. parahemolyticus were 500, 1000, 250, 250, 250, 250, 1000, 500, and 250 microg/ml, respectively. These results suggest that C. osmophloeum leaf essential oil and cinnamaldehyde are beneficial to human health, having the potential to be used for medical purposes and to be utilized as anti-bacterial additives in making paper products.

Acute angle-closure glaucoma resulting from spontaneous hemorrhagic retinal detachment in age-related macular degeneration: case reports and literature review

PURPOSE

Acute angle-closure glaucoma resulting from massive subretinal hemorrhage is a rare and catastrophic complication in age-related macular degeneration. Anticoagulant usage had been strongly correlated with this complication in previously reported cases.

METHODS

Four patients (4 eyes), 3 men and 1 woman, developed angle-closure glaucoma with diffuse subretinal hemorrhage and total hemorrhagic retinal detachment.

RESULTS

Serial funduscopic examinations and echographic studies in 2 eyes showed that the blood gradually accumulated in the subretinal space. It took more than 10 days for the bleeding to build up to bullous hemorrhagic retinal detachment and secondary glaucoma. Anti-glaucomatous agents were given and sclerotomy was performed in 3 of the 4 patients. Phthisical changes were observed subsequently in these 3 eyes. The eye that received early drainage of blood was an exception, and a small degree of residual acuity was retained. Three of the 4 patients had diabetes mellitus, and hypertension and vascular diseases were also present in the same 3 patients.

CONCLUSIONS

Diabetes mellitus might be a predisposing factor for the impaired hemostasis. Anti-glaucomatous agents were of no effect in the management of intraocular pressure. Sclerotomy and drainage of blood help control intraocular pressure and relieve ocular pain. Poor final visual acuity is inevitable. However, phthisical changes might be prevented with early sclerotomy and drainage of blood.

Altered expression of nuclear matrix proteins in etoposide induced apoptosis in HL-60 cells

The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.

Antimite activity of essential oils and their constituents from Taiwania cryptomerioides

Antimite activity of essential oils and their components obtained from Taiwania cryptomerioides Hayata heartwood against Dermatophagoides pteronyssinus (Trouessart) and Dermatophagoides farinae Hughes was investigated in this study. Results from antimite tests demonstrated that the essential oil extracted from T. cryptomerioides heartwood had miticidal activity against D. pteronyssinus and D. farinae with a mortality of 67.0 and 36.7% at the dosage of 12.6 microg/cm2 after 48 h. Alpha-cadinol possessed the strongest antimite activity compared with other components of the T. cryptomeioides heartwood essential oil. The rectified mortalities of D. pteronyssinus and D. farinae were 100% for alpha-cadinol at the dosage of 6.3 microg/cm2. The order of antimite activity of four dominant constituents was alpha-cadinol > T-muurolol > ferruginol > T-cadinol. Paired Student's t-tests showed that there were significant differences between the rectified mortality of alpha-cadinol, T-muurolol, ferruginol and that of T-cadinol at the dosage of 6.3 microg/cm2 after 48 h.

An outbreak of enterovirus 71 infection in Taiwan, 1998. II. Laboratory diagnosis and genetic analysis

BACKGROUND

An epidemic of enterovirus 71 (EV71) occurred in Taiwan from April to December of 1998, with two peaks, one in June and the other in October. Many enteroviruses were isolated in our laboratory from 258 cases during this outbreak. Approximately half of the enteroviruses isolated were EV71 and one fifth were coxsackievirus A16.

OBJECTIVES

To analyze laboratory findings in the EV71 epidemic of 1998 in Taiwan, various EV71 specimens in different cell lines were examined. In addition, genetic analysis of 5' non-coding region (NCR) was performed to analyze the strain variation in this outbreak.

RESULTS

The cytopathic effect induced by EV71 was observed 2-13 (mean of 4.5) days post-inoculation in Vero cells and 4-15 (mean of 6.6) days in green monkey kidney (GMK) cells inoculated with throat swabs. Of the total positive EV71 cases, virus was most frequently obtained from throat swabs (91.7%), less from stools (64.8%), and none from cerebral spinal fluid (CSF). Molecular analyses of EV71 by sequencing the 5' NCR of 34 strains obtained from different clinical categories and various geographic areas showed that their sequences differed (0-13 bp in 681 bp sequenced) by approximately 0-2%. The sequences of these isolates differed from EV71 prototype BrCr or MS strain by 17.5-19%, with the exception of two samples which exhibited nucleotide variation by only 8.9 and 8.2%, when compared to the MS strain.

CONCLUSION

EV71 was most frequently isolated from throat swab specimens in Vero cells. The molecular analyses of the 5' NCR of EV71 revealed that most isolates from this epidemic belonged to a group of closely related clones and only two were in a different group which was clustered with the EV71 MS strain.

Characterization of the roles of the 594-645 region in human endothelial nitric-oxide synthase in regulating calmodulin binding and electron transfer

It has been postulated that a segment (residues 594-645) inserted in the FMN subdomain of human endothelial nitric-oxide synthase (eNOS) plays a crucial role in controlling Ca(2+)-dependent CaM binding for eNOS activity. To investigate its functions, we expressed human eNOS in a baculovirus system with deletion of a 45-residue segment from this region (residues 594-606 and 614-645, designated as Delta45eNOS), and characterized the purified mutant enzyme. In contrast with wild-type eNOS, Delta45eNOS exhibited characteristics resembling inducible NOS (iNOS). It contained an endogenously bound CaM, which was essential in folding and stabilizing this mutant enzyme, and retained 60% of L-citrulline formation in 5 mM EGTA. We also produced four N-terminally truncated reductase domains with or without the 45-residue segment, and either including or excluding the CaM-binding sequence. Basal cytochrome c reductase activity of reductase domains without the 45-residue segment was up to 20 fold greater than that of corresponding insert-containing domains, and higher than CaM-stimulated activity of the wild-type enzyme. A series of mutants with smaller fragment deletion in this region such as Delta594-604, Delta605-612, Delta613-625, Delta626-634, Delta632-639, and Delta640-645 mutants were further characterized. The crude lysate of mutants Delta613-625 and Delta632-639 did not show activity in the presence of Ca(2+)/CaM, while other four mutants had activity comparable to that of WTeNOS. The purified Delta594-604 and Delta605-612 proteins had a 3-5-fold higher affinity for Ca(2+)/CaM, but their L-citrulline forming activity was still 80% dependent upon the addition of Ca(2+)/CaM. Both mutants exhibited a low level of the cytochrome c and ferricyanide reductase activities, which either did not respond to (Delta594-604) or slightly enhanced by (Delta605-612) the exogenous CaM. In contrast, activities of Delta626-634 and Delta640-645 like those of WTeNOS were largely Ca(2+)/CaM-dependent. Thus, our findings indicate that the N-terminal half of the 594-645 segment containing residues 594-612 plays a significant role in regulating Ca(2+)/CaM binding.