Comorbidities, quality of life and patients' willingness to pay for a cure for type 2 diabetes in Taiwan

OBJECTIVES

Diabetes is one of the leading causes of death in Taiwan. However, to date,no study has investigated the patient profile in this country.Therefore,this study aimed to analyse health condition,health-related quality of life and associated financial burden of people with diabetes in Taiwan.

STUDY DESIGN

A cross-sectional survey was conducted using face-to-face interviews with patients with diabetes aged 18 years and over from four hospitals in northern Taiwan. A hypothetical scenario was designed to ascertain subjects' willingness to pay for a cure for diabetes. Ethical approval and consent were obtained from the patients and hospital ethics boards.

METHODS

A double-bounded dichotomous contingent valuation method and maximum log- likelihood model were employed to evaluate the cost of the disease in Taiwan. Anchoring effect .EQ-5D was employed to assess patients' health-related quality of life.

RESULTS

The main comorbidities reported were hypertension(52.2%),cataract(34.3%)and loss of sight(24.3%).The total cost of disease borne by each patient with diabetes is US$3065.7 per year.The total cost of diabetes to society is approximately US$2.96 billion, equivalent to approximately 0.8% of the gross domestic product of Taiwan. The Bureau of National Health Insurance alleviates approximately one-third of the burden for patients.

CONCLUSIONS

The presence of specific comorbidities for patients with diabetes does not have a significant impact on their willingness to pay for a cure. However, body mass index, health- related quality of life and ability to decrease blood glucose level were significantly associated with willingness to pay. With ever-increasing health expenditures around the world,cost containment should start with preventive approaches. Health policies regarding the prevention of diabetes should focus on the promotion of life quality and fitness of the patients.

A Population-Based Cross-Over Randomized Controlled Trial of Breast Cancer Screening with Alternate Mammography and Ultrasound for Women Aged 40 to 49 Years in Taiwan

Background: As there is paucity of data on population-based screening for breast cancer using mammography and ultrasound for oriental young women aged 40-49 years, the peak of incidence rate and high proportion of dense breast, we aimed to evaluate the relative performance of detecting breast cancer between ultrasound and mammography and also to assess complementary efficacy of ultrasound to mammography screening.Methods: A total of 79,691 female residents aged 40-49 years were invited from community in Taiwan since late 2003. These participants were first randomly assigned to mammography (n=20040), ultrasound (n=20088), and control group (n=39563). The two former groups were further done by a cross-over design with mammography and ultrasound on alternate year until 2008. Detection rate and annual incidence rate of interval cancer as a percentage of the control group (I/E ratio) were compared between mammography and ultrasound.Results: The attendance rate of the first round was 59% (11921/20040) for mammography and 56% (11249/20088) for ultrasound. The repeated attendance rate of both groups was 85% in the second round and 91% in the third round. In the first round of screen, the detection rate of breast cancer for the mammography group (0.34%) was 1.5-fold compared with the ultrasound group (0.22%). The additional detection rate was 0.16% contributed from a subsequent ultrasound screen and 0.36% contributed from a subsequent mammogram screen. The combination of mammography with ultrasound was as three to four times as likely to detect breast cancer compared with the control group (annual incidence rate was 0.17%). The I/E ratio was lower after mammography screening than that after ultrasound screening.Conclusion: The current randomized controlled trial not only demonstrated higher detection rate and better performance using mammography but also indicated the complementary role of ultrasound applied to young Taiwanese women. This further suggests the optimal screening modality for young women in Asian country is to combine mammography with ultrasound.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 73.

Combination effects of gefitinib plus cisplatin in non-small cell lung cancer (NSCLC): Why have phase III trials failed?

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Background: Four phase III large scale randomized controlled trials combining standard chemotherapeutics and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in advanced NSCLC have failed to show benefit. The mechanism for the failure is still yet not clear. Methods: Seventeen NSCLC cell lines were tested; two had induced P-glycoprotein (Pgp) over-expression. Three of the 4 EGFR mutants exhibited activating mutations. All lines were simultaneously treated with gefitinib plus cisplatin (GC). Selected 4 lines were tested with paclitaxel plus cisplatin (PC) or gefitinib (PG) and three-drug combination (PCG). The MTT assay with application of classical isobole method and statistical analysis was used and dose-log response curves (DRCs) were examined for evaluating the possible resistance mechanisms. Results: We found that combined GC regimen had significant antagonism at the IC50 level (13/15 lines; mean CI=1.184±0.037, P=0.001). The mean CI values of PCG were higher than or comparable with those of PC or PG in either EGFR wild type or mutant cells. DRC analysis mainly showed non-saturable passive resistance, suggesting that gefitinib 0.001–0.3 μM could interfere with cisplatin cell entry in a dose dependent fashion when cisplatin concentrations over 1–3μM, thus leaded to antagonism. Giving gefitinib 24 hours after administration of cisplatin could abolish the antagonism. Conclusions: In NSCLC cells, combination of GC showed antagonistic interaction likely because gefitinib interfered with cisplatin cell entry. Three-drug combination PCG was not better than two-drug combination PC or PG in either EGFR wild type or mutant cells. Clinically, simultaneously combined EGFR TKI with platinum in NSCLC should be avoided regardless of EGFR mutation status.

[Table: see text]

Evaluation of estrogen receptor expression as a prognostic factor for very young women (below 35 years) with breast cancer in Taiwan

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Background: In the past two decades, the incidence of very young (<35 years) breast cancer in Taiwanese has been rapidly increasing to quite close to that of Caucasian Americans. However, the clinicopathological features of this group of patients appear to be different from their Western counterpart. Here, we sought to determine the prognostic value of ER expression for this newly emerging population in Taiwan. Methods: We retrospectively collected information on all consecutive very young patients (age <35 years) with stage I-III breast cancer treated at National Taiwan University Hospital between 1997 and 2005. ER expression was evaluated by immunohistochemistry on formalin-fixed paraffin-embedded tissue sections. Tumor with more than 10% positive nuclei was considered ER positive. Results: A total of 178 patients with a median age of 32 (range: 21–35) years were included. The median follow-up time was 62.5 (95% confidence interval, 42.0–64.2) months. Univariate analysis showed that ER expression was significantly associated with favorable OS (HR=0.48, P=0.03), but not with DFS (hazard ratio [HR]=0.79, P=0.42). Multivariate analysis showed that stage and ER were independent prognostic factors. Conclusions: In contrast to the findings in Caucasians, ER expression was an independent prognostic factor for favorable overall survival in Taiwanese patients with very young breast cancer.

No significant financial relationships to disclose.

Sporadic and outbreak cases of melioidosis in southern Taiwan: clinical features and antimicrobial susceptibility

BACKGROUND

Melioidosis has been well known to be endemic in Thailand and Northern Australia, and was reported sporadically in Taiwan before 2005.

METHODS

We retrospectively analyzed 58 patients with melioidosis in southern Taiwan from 2000 to 2005, including 40 clustered and 18 sporadic cases, for clinical characteristics and antimicrobial susceptibility.

RESULTS

Fifty-one (88%) cases were found during the rainy season, and there was a significant correlation between the average monthly rainfalls and the case number (r = 0.37; p = 0.001). Diabetes mellitus was the most common underlying disease (35 cases, 60%). The majority (52 cases, 90%) had never traveled abroad before illness, indicating indigenous acquisition of Burkholderia pseudomallei. In comparison, clustered cases were older, less often had underlying diabetes mellitus and had a shorter duration of clinical symptoms before admission than sporadic cases. Acute form of melioidosis predominated, and shock at admission was independently associated with a grave prognosis. Overall, 22% of 58 patients died in hospitals. Ceftazidime, imipenem, meropenem, amoxicillin/clavulanic acid, co-trimoxazole, and doxycycline, as previously recommended, were the potentially therapeutic choices. The role of piperacillin/ tazobactam for melioidosis remains undefined.

CONCLUSIONS

Melioidosis can occur sporadically or in a cluster in diabetic patients during rainy seasons in Taiwan.

Reduced-intensity conditioning for allogeneic hematopoietic stem cell transplantation with fludarabine and melphalan is associated with durable disease control in myelodysplastic syndrome

We retrospectively evaluated the outcome of reduced-intensity conditioning (RIC) followed by allogeneic hematopoietic stem cell transplantation (HCT) in 43 patients with myelodysplastic syndrome (MDS) or AML arising from MDS. All patients received fludarabine plus melphalan followed by an allogeneic HCT from an HLA-identical sibling (SIB: n=19) or unrelated donor (MUD: n=24). Median age was 58 years (range: 30-71). Diagnoses at transplantation were RA (n=8), RARS (n=1), RAEB (n=13), RAEB-T (n=6), or AML arising from MDS (n=15). Of 28 patients with MDS, two patients had low, 10 had intermediate-1, nine had intermediate-2 and seven had high-risk MDS by IPSS criteria. All patients initially engrafted with the median neutrophil recovery of 15 days (range: 9-27). The 2-year overall survival, disease-free survival, relapse and transplant-related mortality were 53.5% (CI 45.2-61.1), 51.2% (CI 43.3-58.5), 16.3% (CI 7.9-30.7) and 35.2% (26.4-45.7), respectively. Grade II-IV acute graft-versus-host disease occurred in 27 (63%) patients. There was no significant survival difference between SIB and MUD-HCT, but the relapse rate was higher among SIB donor recipients when compared to MUD (38.5 versus 7%, P=0.02). RIC with fludarabine plus melphalan was associated with durable disease control and acceptable toxicity in this high-risk cohort.

Sirt1 inhibitor, Sirtinol, induces senescence-like growth arrest with attenuated Ras-MAPK signaling in human cancer cells

The induction of senescence-like growth arrest has emerged as a putative contributor to the anticancer effects of chemotherapeutic agents. Clinical trials are underway to evaluate the efficacy of inhibitors for class I and II histone deacetylases to treat malignancies. However, a potential antiproliferative effect of inhibitor for Sirt1, which is an NAD(+)-dependent deacetylase and belongs to class III histone deacetylases, has not yet been explored. Here, we show that Sirt1 inhibitor, Sirtinol, induced senescence-like growth arrest characterized by induction of senescence-associated beta-galactosidase activity and increased expression of plasminogen activator inhibitor 1 in human breast cancer MCF-7 cells and lung cancer H1299 cells. Sirtinol-induced senescence-like growth arrest was accompanied by impaired activation of mitogen-activated protein kinase (MAPK) pathways, namely, extracellular-regulated protein kinase, c-jun N-terminal kinase and p38 MAPK, in response to epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I). Active Ras was reduced in Sirtinol-treated senescent cells compared with untreated cells. However, tyrosine phosphorylation of the receptors for EGF and IGF-I and Akt/PKB activation were unaltered by Sirtinol treatment. These results suggest that inhibitors for Sirt1 may have anticancer potential, and that impaired activation of Ras-MAPK pathway might take part in a senescence-like growth arrest program induced by Sirtinol.

Neonatal haemorrhagic conjunctivitis: a specific sign of chlamydial infection

OBJECTIVE

To review the bacteriological causes and clinical features of acute neonatal conjunctivitis in a local paediatric centre.

DESIGN

Retrospective review.

SETTING

Paediatric unit of a regional hospital, Hong Kong.

PATIENTS

All neonates who presented to Tuen Mun Hospital from 1 January 1996 to 31 December 2002 with persistent eye discharge and a positive eye swab culture.

MAIN OUTCOME MEASURES

Clinical features of neonates with chlamydial and non-chlamydial conjunctivitis.

RESULTS

Of 90 neonates with positive eye swab or conjunctival scraping cultures, Chlamydia trachomatis was the second most common (n=19, 21%) cause of acute neonatal conjunctivitis after Staphylococcus aureus (n=32, 36%). All of the neonates with chlamydial conjunctivitis were delivered vaginally: two of them had concomitant chlamydial pneumonia. Neisseria gonorrhoeae conjunctivitis was rare (n=1, 1%). None of the mothers of neonates with Chlamydia had any history of sexually transmitted disease. The timing of presentation, gestational age, birth weight, and sex of the neonates did not suggest a risk of chlamydial infection. Nonetheless haemorrhagic eye discharge had a specificity of 100% and positive predictive value of 100% for chlamydial infection. There were no adverse ophthalmological consequences or complications of pyloric stenosis in any neonate following treatment with oral erythromycin.

CONCLUSIONS

Haemorrhagic eye discharge is a highly specific sign of neonatal chlamydial conjunctivitis. Early and prompt treatment with oral erythromycin is safe and effective.

Thin-layer ablation of human esophageal epithelium using a bipolar radiofrequency balloon device

BACKGROUND

The goal of this study was to determine the optimal treatment parameters for the ablation of human esophageal epithelium using a balloon-based bipolar radiofrequency (RF) energy electrode.

METHODS

Immediately prior to esophagectomy, subjects underwent esophagoscopy and ablation of two separate, 3-cm long, circumferential segments of non-tumor-bearing esophageal epithelium using a balloon-based bipolar RF energy electrode (BARRX Medical, Inc., Sunnyvale, CA, USA). Subjects were randomized to one of three energy density groups: 8, 10, or 12 J/cm2. RF energy was applied one time (1x) proximally and two times (2x) distally. Following resection, sections from each ablation zone were evaluated using H&E and diaphorase. Histological endpoints were complete epithelial ablation (yes/no), maximum ablation depth, and residual ablation thickness after tissue slough. Outcomes were compared according to energy density group and 1x vs 2x treatment.

RESULTS

Thirteen male subjects (age, 49-85 years) with esophageal adenocarcinoma underwent the ablation procedure followed by total esophagectomy. Complete epithelial removal occurred in the following zones: 10 J/cm2 (2x) and 12 J/cm2 (1x and 2x). The maximum depth of injury was the muscularis mucosae: 10 and 12 J/cm2 (both 2x). A second treatment (2x) did not significantly increase the depth of injury. Maximum thickness of residual ablation after tissue slough was only 35 microm.

CONCLUSIONS

Complete removal of the esophageal epithelium without injury to the submucosa or muscularis propria is possible using this balloon-based RF electrode at 10 J/cm2 (2x) or 12 J/cm2 (1x or 2x). A second application (2x) does not significantly increase ablation depth. These data have been used to select the appropriate settings for treating intestinal metaplasia in trials currently under way.

Treatment of volatile organic compounds from polyurethane and epoxy manufacture by a trickle-bed air biofilter

The objective of this study was to evaluate the performance of a trickle-bed air biofilter (TBAB) for the removal of volatile organic compound (VOC) produced during polyurethane (PU) and epoxy manufacture. The major VOCs emitted are ethyl acetate (EA) for PU and EA and xylene for epoxy production. For the treatment of VOCs emitted during PU production, the employed coal carbon appears to be efficient as a VOC concentration buffer in the biofiltration of waste gases. Based on the results of EA and total hydrocarbon (THC) removal, it was concluded that the TBAB is suitable for controlling VOC emission during PU manufacture. For the treatment of VOCs emitted during epoxy production, it was found that the performance of the TBAB is relatively poor due to the lack of VOC sources. However, this problem could be easily solved by mixing the VOCs emitted during PU and epoxy manufacture.

Laparoscopic esophagectomy

Minimally invasive esophagectomy is emerging as an alternative option to open esophagectomy for benign and malignant esophageal diseases. This article provides a detailed review of the history of minimally invasive esophagectomy and an update on the currently accepted techniques for minimally invasive esophagectomy and its outcomes.

The present and future organisation of Veterinary Services in Asia: the examples of the Republic of Korea and Japan

The Veterinary Services of the Republic of Korea and Japan are reviewed and summarised. To cope with ever-increasing demands on Veterinary Services, both countries have made continued efforts to expand the services, which currently only have a limited number of government personnel. To overcome some of the problems associated with international trade, e.g. outbreaks of foot and mouth disease and classical swine fever (hog cholera), the authorities of the Republic of Korea are considering strengthening quarantine services by combining the National Veterinary Research and Quarantine Service and the National Plant Quarantine Service of the Ministry of Agriculture and Forestry (MAF). In the field of veterinary public health services, the Republic of Korea and Japan have different organisational structures. All Veterinary Services, including veterinary public health, are kept within the MAF in the Republic of Korea, whereas in Japan, the Ministry of Agriculture, Forestry and Fisheries (MAFF) deals with general animal production and health services and the Ministry of Health, Labour and Welfare (MHLW) deals with the safety of animal products, food poisoning and the prevention/control of zoonoses, such as rabies and Q fever. In Japan, after the occurrence of bovine spongiform encephalopathy in 2001, the authorities undertook a thorough review of the Veterinary Services, focusing particularly on food safety. A reorganisation of the administrative structure was proposed, and will be completed by the end of 2003. Subject to the approval of the Diet (House of Councillors), an independent 'Food Safety Commission' will be created within the cabinet office which will undertake risk analyses related to foods, and risk management will be carried out by the relevant ministry, i.e. the MAFF or the MHLW. The Animal Health Division of the MAFF will also be moved from the Livestock Industry Department to a new 'Consumer Safety Department' of the MAFF, where additional responsibilities in fish health control and feed safety control will be assumed.

Current status of minimally invasive esophagectomy

Minimally invasive esophagectomy is emerging as an option in the management of benign and malignant esophageal diseases. With minimally invasive esophagectomy, the conventional laparotomy is substituted with laparoscopy and the open thoracotomy with thoracoscopy. This article discusses the surgical techniques and outcomes for a variety of minimally invasive esophagectomy options.

Features predicting adverse outcomes of status epilepticus in childhood

OBJECTIVE

To examine variables that might predict abnormal outcome of status epilepticus among children.

DESIGN

Retrospective study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

All children younger than 15 years who were admitted to the paediatric intensive care unit with status epilepticus between 1997 and 2002.

MAIN OUTCOME MEASURES

Neurodevelopmental outcomes.

RESULTS

Two of the 25 patients died, resulting in a mortality rate of 8%. No deaths were due to status epilepticus itself. No patient with febrile or idiopathic status epilepticus developed epilepsy. Neurological deterioration was observed in a quarter (six of 23) of the survivors. Symptomatic aetiology (acute or remote) and refractory status epilepticus were associated with adverse outcomes (P<0.05). Young age at status epilepticus (<12 months) and duration of status epilepticus (>60 minutes) tended to be more frequent among those who developed adverse outcome. Rectal diazepam was given before hospital arrival in only four patients.

CONCLUSIONS

Paediatric patients with status epilepticus who had normal neurodevelopmental status before the onset of an attack and who did not sustain an acute insult to the central nervous system or have progressive encephalopathy, had favourable outcomes. Prompt use of rectal diazepam or buccal midazolam administered by caretakers or paramedics should be encouraged.

Antibody responses to human rotavirus (HRV) in gnotobiotic pigs following a new prime/boost vaccine strategy using oral attenuated HRV priming and intranasal VP2/6 rotavirus-like particle (VLP) boosting with ISCOM

Safer and more effective human rotavirus (HRV) vaccines are needed. We evaluated oral priming with attenuated WaHRV (AttHRV) followed by boosting with two intranasal (IN) doses of VP2/6 virus-like particles (2/6 VLP) with immunostimulating complexes (ISCOM) to determine if this regimen induces protection against diarrhoea and viral shedding in the gnotobiotic pig model. IgM, IgA and IgG antibody titres in serum and intestinal contents were quantified by enzyme-linked immunosorbent assay (ELISA) and serum neutralizing antibody titres were measured by a virus neutralization (VN) test. Seven groups of neonatal gnotobiotic pigs were vaccinated at post-inoculation days (PID) 0, 10 and 21 and challenged with virulent WaHRV at PID 28. The vaccine groups included: (1, 2) oral priming with AttHRV and boosting with two IN immunizations with 2/6 VLP-ISCOM (Att + 2/6 VLP-ISCOM) at VLP concentrations of 250 micro g or 25 micro g; (3, 4) three IN immunizations with 2/6 VLP-ISCOM at VLP concentrations of 250 micro g or 25 micro g (2/6 VLP-ISCOM); (5) three oral immunizations with AttHRV (3xAttHRV); (6) one oral immunization with AttHRV (1xAttHRV); (7) controls (ISCOM matrix and/or diluent). The pigs that received 3xAttHRV or Att + 2/6 VLP250-ISCOM had the highest protection rates against diarrhoea upon challenge at PID 28 with virulent WaHRV. The IgA antibody titres to HRV in intestinal contents were significantly higher in the Att + 2/6 VLP250-ISCOM group than in all other groups prechallenge (PID 28). Serum VN antibody titres were statistically similar after the first inoculation among the groups given AttHRV, but at PID 28 VN antibody titres were significantly higher for the 3xAttHRV and Att + 2/6 VLP250-ISCOM groups than for the 1xAttHRV group suggesting that boosting with 2/6 VLP also boosted VN antibody responses. In humans, intestinal IgA antibodies have been correlated with protection against symptomatic reinfection. Thus the vaccine regimen of one oral dose of AttHRV and two IN immunizations with 2/6 VLP250-ISCOM may be an alternative to multiple-dose live oral vaccines in humans.

Pretargeting for cancer radioimmunotherapy with bispecific antibodies: role of the bispecific antibody's valency for the tumor target antigen

The use of a divalent effector molecule improves bispecific antibody (bsMAb) pretargeting by enabling the cross-linking of monovalently bound bsMAb on the cell surface, thereby increasing the functional affinity of a bsMAb. In this work, it was determined if a bsMAb with divalency for the primary target antigen would improve bsMAb pretargeting of a divalent hapten. The pretargeting of a (99m)Tc-labeled divalent DTPA-peptide, IMP-192, using a bsMAb prepared by chemically coupling two Fab' fragments, one with monovalent specificity to the primary target antigen, carcinoembryonic antigen (CEA), and to indium-loaded DTPA [DTPA(In)], was compared to two other bsMAbs, both with divalency to CEA. One conjugate used the whole anti-CEA IgG, while the other used the anti-CEA F(ab')(2) fragment to make bsMAbs that had divalency to CEA, but with different molecular weights to affect their pharmacokinetic behavior. The rate of bsMAb blood clearance was a function of molecular weight (IgG x Fab' < F(ab')(2) x Fab' < Fab' x Fab' conjugate). The IgG x Fab' bsMAb conjugate had the highest uptake and longest retention in the tumor. However, when used for pretargeting, the F(ab')(2) x Fab' conjugate allowed for superior tumor accretion of the (99m)Tc-IMP-192 peptide, because its more rapid clearance from the blood enabled early intervention with the radiolabeled peptide when tumor uptake of the bsMAb was at its peak. Excellent peptide targeting was also seen with the Fab' x Fab' conjugate, albeit tumor uptake was lower than with the F(ab')(2) x Fab' conjugate. Because the IgG x Fab' bsMAb cleared from the blood so slowly, when the peptide was given at the time of its maximum tumor accretion, the peptide was captured predominantly by the bsMAb in the blood. Several strategies were explored to reduce the IgG x Fab' bsMAb remaining in the blood to take advantage of its 3-4-fold higher tumor accretion than the other bsMAb conjugates. A number of agents were tested, including those that could clear the bsMAb from the blood (e.g., galactosylated or nongalactosylated anti-id antibody) and those that could block the anti-DTPA(In) binding arm [e.g., DTPA(In), divalent-DTPA(In) peptide, and DTPA coupled to bovine serum albumin (BSA) or IgG]. When clearing agents were given 65 h after the IgG x Fab' conjugate (time of maximum tumor accretion for this bsMAb), (99m)Tc-IMP-192 levels in the blood were significantly reduced, but a majority of the peptide localized in the liver. Increasing the interval between the clearing agent and the time the peptide was given to allow for further processing of the bsMAb-clearing agent complex did not improve targeting. At the dose and level of substitution tested, galacosylated BSA-DTPA(In) was cleared too quickly to be an effective blocking agent, but BSA- and IgG-DTPA(In) conjugates were able to reduce the uptake of the (99m)Tc-IMP-192 in the blood and liver. Tumor/nontumor ratios compared favorably for the radiolabeled peptide using the IgG x Fab'/blocking agent combination and the F(ab')(2) x Fab' (no clearing/blocking agent), and peptide uptake 3 h after the blocking agent even exceeded that of the F(ab')(2) x Fab'. However, this higher level of peptide in the tumor was not sustained over 24 h, and actually decreased to levels lower than that seen with the F(ab')(2) x Fab' by this time. These results demonstrate that divalency of a bsMAb to its primary target antigen can lead to higher tumor accretion by a pretargeted divalent peptide, but that the pharmacokinetic behavior of the bsMAb also needs to be optimized to allow for its clearance from the blood. Otherwise, blocking agents will need to be developed to reduce unwanted peptide uptake in normal tissues.

Design of a retroviral-mediated ecdysone-inducible system and its application to the expression profiling of the PTEN tumor suppressor

We have engineered the ecdysone-inducible mammalian expression system for general retroviral delivery to cultured mammalian cells. We inducibly expressed PTEN in the glioblastoma cell line, U87MG, lacking this gene. Because nearly all cells are recruited on induction, we find both up- and down-regulated genes by cDNA microarray analysis. The changes we see are similar to those observed after treatment with LY294002, an inhibitor of phosphatidylinositol 3-OH kinase, fully consistent with the model that PTEN antagonizes phosphatidylinositol 3-OH kinase. Both treatments result in suppressed expression of the transforming growth factor (TGF)-beta gene and the genes of the cholesterol biosynthesis pathway. Our results illustrate the power of using a fully inducible expression system in conjunction with cDNA microarray analysis for exploring gene function.

Recent advances in brain injury research: a new human head model development and validation

Many finite element models have been developed by several research groups in order to achieve a better understanding of brain injury. Due to the lack of experimental data, validation of these models has generally been limited. Consequently, applying these models to investigate brain responses has also been limited. Over the last several years, several versions of the Wayne State University brain injury model (WSUBIM) were developed. However, none of these models is capable of simulating indirect impacts with an angular acceleration higher than 8,000 rad/s(2). Additionally, the density and quality of the mesh in the regions of interest are not detailed and sensitive enough to accurately predict the stress/strain level associated with a wide range of impact severities. In this study, WSUBIM version 2001, capable of simulating direct and indirect impacts with a combined translational and rotational acceleration of the head up to 200 g and 12,000 rad/s(2) has been developed. This new finely meshed model, consisting of more than 314,500 elements and 281,800 nodes, also simulates an anatomically detailed facial bone model. An additional new feature of the model is the damageable material property representation of the facial bone and the skull, allowing it to simulate bony fractures. The model was subjected to extensive validation using published cadaveric test data. These data include the intracranial and ventricular pressure data reported by Nahum et al. (1977) and Trosseille et al. (1992), the relative displacement data between the brain and the skull reported by King et al. (1999) and Hardy et al. (2001), and the facial impact data reported by Nyquist et al. (1986) and Allsop et al. (1988). With the enhanced accuracy of model predictions offered by this new model, along with new experimental data, it is hoped that it will become a powerful tool to further our understanding of the mechanisms of injury and the tolerance of the brain to blunt impact.

[Acute myocardial infarction in the postoperative period in an elderly man with low coronary risk factor before the operation]

An 86-year-old man complicated by severe asthma developed myocardial infarction after the operation of abdominal aortic aneurysm. Emergency coronary angiography (CAG) revealed 99% stenosis of main trunks of left coronary artery (LMT). Because the patient had been without major coronary risk factors, it was difficult to predict coronary lesions preoperatively. Elderly patients have frequently latent complications not detected by usual consultation. Therefore, in elderly patients, we have to evaluate each individual risk factor more rigidly, and perform more thorough preoperative tests, including CAG.

Pharmacokinetic studies of 2-amino-9-(3-acetoxymethyl-4-isopropoxycarbonyl-oxybut-1-yl)purine, an oral prodrug for the antiviral agent penciclovir

2-Amino-9-(3-acetoxymethyl-4-isopropoxycarbonyloxybut-1-yl)- purine (SK1899) was tested as an oral prodrug for penciclovir. SK1899 was administered orally to rats and dogs at doses up to 2 and 0.68 mmol/kg, respectively. SK1899 was well absorbed, and the major metabolites detected in plasma and urine were penciclovir, the active antiviral compound, and 6-deoxypenciclovir (M4) in both species. In rats, SK1899 was rapidly and extensively metabolized to penciclovir, which reached the peak plasma concentration (C(max)) of 39.5 microM at 0.5 h after 0.2-mmol/kg dosing. The area under the plasma concentration-time curve (AUC) for penciclovir was 57.5 microM x h. After an oral dose of 0.034 mmol/kg to dogs, extensive conversion of SK1899 to penciclovir also occurred with slower rate of formation of penciclovir from M4 than in rats. The mean C(max) and AUC for penciclovir were 4.5 microM at 2.7 h and 28.2 microM x h, respectively. The 0- to 24-h urinary recovery of penciclovir represented 36.1 and 36.3% of dose to rats and dogs, respectively. Radioactivity was found in fetuses following an oral administration of [(14)C]SK1899 to pregnant rats, but no significant accumulation was observed. Although substantial milk transfer of [(14)C]SK1899 occurred in rats, the radioactivity in milk was rapidly cleared. The values of C(max), AUC, and urinary recovery of penciclovir after dosing with SK1899 to rats and dogs were similar or slightly higher than those from famciclovir. These data indicate that introduction of an isopropoxy carbonate group into one of the two hydroxyl groups of M4 did not significantly alter the oral bioavailability of penciclovir compared with famciclovir.

Synthesis and phosphodiesterase 5 inhibitory activity of novel phenyl ring modified sildenafil analogues

New sildenafil analogues containing an ether ring fused into the phenyl moiety, 6a--d and 7a--d, were efficiently synthesized from the readily available starting materials, 1a--d and 2, in five steps. Ab initio calculations indicated that introduction of a cyclic ether to the phenyl group might enhance the co-planarity of the molecule. The torsional angles were calculated to be 2--3 degrees for the 5-membered cyclic ether derivatives, 6a, 6c, 7a, and 7c, and 12--16 degrees for the 6-membered ones, 6b, 6d, 7b, and 7d. On the other hand, sildenafil showed the least co-planarity with the torsional angle of 23 degrees compared with the target compounds, 6a--d and 7a--d. In the enzyme assay, however, the in vitro PDE 5 inhibitory activity was found out to be inversely related to the degree of co-planarity. In other words, the least planar sildenafil showed the highest activity, and the most planar 5-membered cyclic ether derivatives were least active by 100--200-fold compared with sildenafil. Our study clearly demonstrated that the open chain 2'-alkoxy group of the phenyl ring, although less effective for inducing the co-planarity, seemed to act as a much better lipophilic requirement than the cyclic alkoxy moiety.

Synthesis and biological evaluation of novel A-ring modified hexacyclic camptothecin analogues

Eleven A-ring modified hexacyclic analogues of camptothecin (CPT) containing a 1,4-oxazine ring were synthesized from 10-hydroxycamptothecin (11a) and 7-ethyl-10-hydroxycamptothecin (3) (SN-38) in four to five steps and were subjected to the biological tests such as cytotoxicity, topoisomerase I (Topo I) inhibitory activity, acetylcholinesterase (AChE) inhibition, and stability in human plasma. Four compounds 15a, 15b, 16a, and 16c were about 2-fold more potent than topotecan and as potent as CPT toward human cancer cell lines A549, H128, WiDr, MKN45, SK-OV-3, and SK-BR-3 in vitro, even though the most active compound 15b was slightly less potent than SN-38. The potency of Topo I inhibition of these compounds showed relatively good correlation with their cytotoxicity. Most of the compounds exhibited AChE inhibitory activity weaker (9 +/- 2 to 20 +/- 3%) than CPT (23 +/- 5%) or topotecan (20 +/- 4%) and similar to SN-38 (13 +/- 2%), indicating that they might have little effect on causing early diarrhea. The stability of lactone forms of these compounds in human plasma seemed to be much higher than that of CPT and similar to that of topotecan but lower than that of SN-38. Among the new hexacyclic CPT analogues, compound 15b showed higher antitumor activity against human tumor xenograft, WiDr, in nude mice compared to that of SN-38. The most promising compound 15b has been selected for further development.

Removal of ethylacetate vapor from waste gases by a trickle-bed air biofilter

Biofilter system is a relatively new process that has been proven to be more cost-effective than traditional technologies such as carbon adsorption, liquid scrubbing, condensation, thermal incineration, and catalytic incineration for removing low-strength volatile organic compounds from waste gases. The trickle-bed air biofilter (TBAB) performance for ethylacetate (EA) removal was evaluated under different influent loadings. In the pseudo-steady states, the elimination capacity increased, but the removal efficiency decreased with increased influent loading. More than 95 and 90% removal efficiencies could be achieved for EA loadings below 490 and 810 g m(-3) h(-1), respectively. The TBAB appears to be very effective for controlling EA emission under low to high loading conditions, and the effectiveness could be maintained over 190 days of laboratory operation.

Effects of nicotine on APP secretion and Abeta- or CT(105)-induced toxicity

Several lines of evidence indicated that overexpression or aberrant processing of amyloid precursor protein (APP) is causally related to Alzheimer's disease (AD). Amyloid precursor protein is principally cleaved within the amyloid beta protein domain to release a large soluble ectodomain (APPs), known to have a wide range of trophic functions. The central hypothesis guiding this review is that nicotine may play an important role in APP secretion and protection against toxicity induced by APP metabolic fragments (beta-amyloid [Abeta], carboxyl terminal [CT]). Findings from our experiments have shown that nicotine enhances the release of APPs, which has neurotrophic and neuroprotective activities in concentration-dependent (>50 micromol/L) and time-dependent (>2 hours) manners. In addition, pretreatment of nicotine (>10 micromol/L for 24 hours) partially prevented Abeta or CT(105)-induced cytotoxicity in primary cultured neuron cells, and the effects of nicotine-induced protection were inhibited by the pretreatment with a nicotine alpha-bungarotoxin. Nicotine (>10 micromol/L for 24 hours) partially inhibited CT(105)-induced cytotoxicity when PC12 cells was transfected with CT(105). From these results, we proposed that nicotine or nicotinic receptor agonist treatment might improve the cognitive functions not only by supplementation of cholinergic neurotransmission, but also by protecting Abeta- or CT(105)-induced neurotoxicity probably through the increased release of APPs and the activation of nicotinic receptors.

In vivo trafficking and catabolism of IgG1 antibodies with Fc associated carbohydrates of differing structure

We have now produced mouse-human chimeric IgG1 in wild-type Chinese hamster ovary (CHO) cell lines Pro-5 as well as in the glycosylation mutants Lec 2, Lec 8, and Lec 1. Analysis of the attached carbohydrates shows those present on IgG1-Lec 1 were mannose terminated. Carbohydrate present on IgG1-Lec8 was uniformly biantennary terminating in N-acetylglucosamine. The glycosylation profiles of IgG1-Lec 2 and IgG1-Pro-5 were heterogeneous. Only IgG1-Pro-5 was sialylated with sialic acid present on only a small percentage of the carbohydrate structures. When the in vivo fate of antibodies labeled with (125)I-lactotyramine was determined, it was found that the majority of all of the antibodies, irrespective of the structure of their attached carbohydrate, is catabolized in the skin and muscle. However, the attached carbohydrate structure does influence the amount that is catabolized in the liver and the liver serves as a major site for the catabolism of proteins bearing carbohydrate with the Lec2 (with terminal galactose) or Lec1(with terminal mannose) structure.