LASSO-derived model for the prediction of lean-non-alcoholic fatty liver disease in examinees attending a routine health check-up

BACKGROUND

Lean individuals with non-alcohol fatty liver disease (NAFLD) often have normal body size but abnormal visceral fat. Therefore, an alternative to body mass index should be considered for prediction of lean-NAFLD. This study aimed to use representative visceral fat links with other laboratory parameters using the least absolute shrinkage and selection operator (LASSO) method to construct a predictive model for lean-NAFLD.

METHODS

This retrospective cross-sectional analysis enrolled 2325 subjects with BMI < 24 kg/m2 from medical records of 51,271 examinees who underwent a routine health check-up. They were randomly divided into training and validation cohorts at a ratio of 1:1. The LASSO-derived prediction model used LASSO regression to select 23 clinical and laboratory factors. The discrimination and calibration abilities were evaluated using the Hosmer-Lemeshow test and calibration curves. The performance of the LASSO model was compared with the fatty liver index (FLI) model.

RESULTS

The LASSO-derived model included four variables-visceral fat, triglyceride levels, HDL-C-C levels, and waist hip ratio-and demonstrated superior performance in predicting lean-NAFLD with high discriminatory ability (AUC, 0.8416; 95% CI: 0.811-0.872) that was comparable with the FLI model. Using a cut-off of 0.1484, moderate sensitivity (75.69%) and specificity (79.86%), as well as high negative predictive value (95.9%), were achieved in the LASSO model. In addition, with normal WC subgroup analysis, the LASSO model exhibits a trend of higher accuracy compared to FLI (cut-off 15.45).

CONCLUSIONS

We developed a LASSO-derived predictive model with the potential for use as an alternative tool for predicting lean-NAFLD in clinical settings.

Clinical Outcomes and Cost-Effectiveness of Osteoporosis Screening With Dual-Energy X-ray Absorptiometry

OBJECTIVE

This study aimed to evaluate the clinical outcomes and cost-effectiveness of dual-energy X-ray absorptiometry (DXA) for osteoporosis screening.

MATERIALS AND METHODS

Eligible patients who had and had not undergone DXA screening were identified from among those aged 50 years or older at Kaohsiung Veterans General Hospital, Taiwan. Age, sex, screening year (index year), and Charlson comorbidity index of the DXA and non-DXA groups were matched using inverse probability of treatment weighting (IPTW) for propensity score analysis. For cost-effectiveness analysis, a societal perspective, 1-year cycle length, 20-year time horizon, and discount rate of 2% per year for both effectiveness and costs were adopted in the incremental cost-effectiveness (ICER) model.

RESULTS

The outcome analysis included 10337 patients (female:male, 63.8%:36.2%) who were screened for osteoporosis in southern Taiwan between January 1, 2012, and December 31, 2021. The DXA group had significantly better outcomes than the non-DXA group in terms of fragility fractures (7.6% vs. 12.5%, P < 0.001) and mortality (0.6% vs. 4.3%, P < 0.001). The DXA screening strategy gained an ICER of US$ -2794 per quality-adjusted life year (QALY) relative to the non-DXA at the willingness-to-pay threshold of US$ 33004 (Taiwan's per capita gross domestic product). The ICER after stratifying by ages of 50-59, 60-69, 70-79, and ≥ 80 years were US$ -17815, US$ -26862, US$ -28981, and US$ -34816 per QALY, respectively.

CONCLUSION

Using DXA to screen adults aged 50 years or older for osteoporosis resulted in a reduced incidence of fragility fractures, lower mortality rate, and reduced total costs. Screening for osteoporosis is a cost-saving strategy and its effectiveness increases with age. However, caution is needed when generalizing these cost-effectiveness results to all older populations because the study population consisted mainly of women.

Examining patient flow in a tertiary hospital's emergency department at a low coronavirus prevalence region

BACKGROUND

Taiwan's successful containment of the COVID-19 outbreak prior to 2021 provided a unique environment for the surveillance of unnecessary emergency medical use. The aim of the study is to examine the impact of the coronavirus disease (COVID-19) pandemic on the patient flow in the emergency department (ED) of a tertiary hospital over 1 year in southern Taiwan, a region with low COVID-19 prevalence.

METHODS

Cross-sectional observational study was conducted from January to December 2020. Essential parameters of patient flow in the ED between January and February 2020 and the subsequent 11-month period were compared to data from 2019. Data were analyzed with descriptive statistics, using an independent sample t-test or Mann-Whitney U test, as applicable.

RESULTS

The ED census showed an acute decline (- 30.8%) from January to February 2020, reaching its nadir (- 40.5%) in April 2020. From February to December 2020, there was an average decrease of 20.3% in ED attendance (p < 0.001). The impact was most significant in ambulatory visits, lower-urgency acuity (level III) visits, and pediatric visits, without change in the acuity proportion. The length of stay shortened mainly in the adult division, which typically had an overcrowding problem (median, 5.7-4.4 hours in discharge; 24.8-16.9 hours in hospitalization; p < 0.001). The incidence of 72-hour unscheduled return visits was also reduced (4.1-3.5%, p = 0.002).

CONCLUSIONS

In contrast to devastated regions, the impact on the ED patient flow in regions having low COVID-19 prevalence highlights a remodeling process of emergency medical care that would improve overcrowding.

Risk Factors and Prevalence of mcr-1-Positive Escherichia coli in Fecal Carriages Among Community Children in Southern Taiwan

Colistin is the last resort antimicrobial for treating multidrug-resistant gram-negative bacterial infections. The plasmid-mediated colistin resistance gene, mcr-1, crucially influences colistin’s resistance transmission. Human fecal carriages of mcr-1-positive Escherichia coli (E. coli) were detected in many regions worldwide; however, only a few studies have focused on children. Therefore, we identified the prevalence and risk factors of mcr-1-positive E. coli in fecal carriages among community children in Southern Taiwan. In this study, 510 stool samples were collected from April 2016 to August 2019 from the pediatric department at a medical center in Southern Taiwan. These samples were collected within 3 days after admission and were all screened for the presence of the mcr-1 gene. Diet habits, travel history, pet contact, and medical history were also obtained from participants to analyze the risk factors of their fecal carriages to mcr-1-positive E. coli. Antimicrobial susceptibility testing was determined using the VITEK 2 system and the broth microdilution test. Twelve mcr-1-positive E. coli. were isolated from 2.4% of the fecal samples. Through multivariate analysis, frequent chicken consumption (at least 3 times per week) had a significantly positive association with the presence of mcr-1-positive E. coli in fecal carriages (adjust odds ratio 6.60, 95% confidence interval1.58– 27.62, p = 0.033). Additionally, multidrug resistance was more common in mcr-1-positive E. coli. (75.0% vs. 39.5%, p = 0.031) than in non-mcr-1-positive Escherichia coli. Furthermore, the percentage of extraintestinal pathogenic E. coli in mcr-1-positive isolates was 83.3%. Some multi-locus sequence types in our mcr-1-positive E. coli were also similar to those isolated from food animals in the literature. The prevalence of fecal carriages of mcr-1-positive E. coli was low among community children in Southern Taiwan. Our data shows that chicken consumption with a higher frequency increases the risk of mcr-1-positive E. coli. in fecal carriages.

Risk Prediction of Barrett's Esophagus in a Taiwanese Health Examination Center Based on Regression Models

Determining the target population for the screening of Barrett's esophagus (BE), a precancerous condition of esophageal adenocarcinoma, remains a challenge in Asia. The aim of our study was to develop risk prediction models for BE using logistic regression (LR) and artificial neural network (ANN) methods. Their predictive performances were compared. We retrospectively analyzed 9646 adults aged ≥20 years undergoing upper gastrointestinal endoscopy at a health examinations center in Taiwan. Evaluated by using 10-fold cross-validation, both models exhibited good discriminative power, with comparable area under curve (AUC) for the LR and ANN models (Both AUC were 0.702). Our risk prediction models for BE were developed from individuals with or without clinical indications of upper gastrointestinal endoscopy. The models have the potential to serve as a practical tool for identifying high-risk individuals of BE among the general population for endoscopic screening.

A Large Spatial Survey of Colistin-Resistant Gene mcr-1-Carrying E. coli in Rivers across Taiwan

BACKGROUND

Colistin is one of the last-line antimicrobial agents against life-threatening infections. The distribution of the colistin resistance gene mcr-1 has been reported worldwide. However, most studies have focused on the distribution of mcr-1-positive bacteria in humans, animals, food, and sewage; few have focused on their distribution in natural environments.

METHOD

We conducted a large spatial survey of mcr-1-positive Escherichia coli at 119 sites in 48 rivers, covering the entire island of Taiwan. We investigated the relationship between the livestock or poultry density in the surveyed riverine area and the number of mcr-1-positive E. coli in the river water. We then sequenced and characterized the isolated mcr-1-positive plasmids.

RESULTS

Seven mcr-1 positive E. coli were isolated from 5.9% of the sampling sites. The mcr-1-positive sites correlated with high chicken and pig stocking densities but not human population density or other river parameters. Four of the mcr-1-positive E. coli strains harbored epidemic IncX4 plasmids, and three of them exhibited identical sequences with a size of 33,309 bp. One of the plasmids contained identical 33,309 bp sequences but carried an additional 5711-bp transposon (Tn3 family). To our knowledge, this is the first demonstration that mcr-1-carrying IncX4 plasmids can contain an insertion of such transposons. All mcr-1-positive isolates belonged to phylogenetic group A and harbored few known virulence genes.

CONCLUSION

This study showed a positive relationship between the number of mcr-1-positive sites and high livestock and poultry density. The sequencing analyses indicated that the epidemic plasmid in the mcr-1 isolates circulates not only in humans, animals, and food but also in the associated environments or natural habitats in Taiwan, suggesting that the surveillance of antibiotics-resistance genes for livestock or poultry farm quality control should include their associated environments.

[One patient with severe phenol burn complicated with acute poisoning]

On April 26, 2018, a 55-year-old male patient with severe phenol burn complicated with acute poisoning was admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine. The patient quickly developed the symptoms of central nervous system including blurred consciousness and restlessness, anuria, and respiratory failure. After self-rescue before admission and a series of measures in hospital including wound decontamination to reduce phenol absorption, rapid massive infusion and hemodialysis+ hemoperfusion, continuous renal replacement therapy for speeding up phenol excretion and organ function maintenance, the poisoning symptoms were effectively alleviated, and the patient was finally rescued successfully and discharged on post injury day 29. This case suggests that early hemodialysis combined with hemoperfusion and continuous renal replacement therapy are effective methods for treating severe phenol burn complicated with acute poisoning.

Kinetics of hepatitis B surface antigen and estimated glomerular filtration rate in telbivudine-treated hepatitis B patients with different rescue strategies

This study investigated the kinetics of estimated glomerular filtration rate (eGFR) and quantitative hepatitis B surface antigen (qHBsAg) in telbivudine (LdT)-treated chronic hepatitis B (CHB) patients whose treatment was subsequently adjusted with the adding on adefovir or by switching to tenofovir disoproxil fumarate (TDF) as rescue. Of 295 CHB patients initially treated with LdT, 102 of them who subsequently receiving either adding-on adefovir (group A, n = 58) or switching to TDF (group B, n = 44) for more than 24 months were enrolled. Serial eGFR and qHBsAg levels (3 to 6 monthly) in both LdT monotherapy and rescue therapy periods were analyzed retrospectively. Subsequent decline of qHBsAg especially in rescue therapy period were noted (p<0.001 and p = 0.068 in group A and B). However, patients in group B achieved a significant increase of eGFR (p = 0.010) in LdT monotherapy period but had a significant decline of eGFR (p<0.001) in rescue therapy period. In contrast, patients in group A maintained eGFR levels in both periods. Meanwhile, switch to TDF (hazard ratio: 3.036; 95% confidence interval: 1.040-8.861; p = 0.042) was the sole factor related to the decrease of eGFR>20% from baseline. Both rescue therapies achieved subsequent declines of qHBsAg over time but caused different changes in eGFR. LdT-based rescue therapy maintained eGFR but TDF switching therapy descended eGFR. Therefore, it is essential to monitor patient's renal function intensively when switching from LdT to TDF as a rescue strategy.

P2556TXNDC5 is a novel therapeutic target of atrial fibrosis and fibrillation

Background

Atrial fibrillation (AF), one of the most common cardiac arrhythmias, increases the risk of stroke, systemic embolization and cardiovascular mortality. Atrial fibrosis, a hallmark of chronic AF, provides substrates to initiate/propagate fibrillation waves in the atria. There, however, lacks effective and specific therapeutics targeting atrial fibrosis. We have recently identified an endoplasmic reticulum (ER) protein thioredoxin domain containing 5 (TXNDC5) as a critical mediator of cardiac ventricular fibrosis. We hypothesized that TXNDC5 could also play an important role in the pathogenesis of atrial fibrosis and fibrillation.

Purpose

To determine the role of TXNDC5 in atrial fibrosis and fibrillation.

Methods and results

TXNDC5 transcript and protein levels were both significantly upregulated in the atrial tissue from patients with AF. In addition, TXNDC5 mRNA expression levels were positively correlated with those of transcripts encoding transforming growth factor β1 (TGFβ1) and extracellular matrix (ECM) proteins in human atrial tissue. Knockdown of TXNDC5 in human atrial fibroblasts (hAF) attenuated TGFβ1–induced hAF activation, proliferation and ECM protein upregulation, whereas overexpression of TXNDC5 was sufficient to trigger hAF activation, proliferation and ECM protein production. Further experiments revealed that the fibrogenic effects of TXNDC5 were dependent on c-Jun N-terminal kinase (JNK) signaling. Furthermore, using α-MHC-TGFβcys33ser mice, a transgenic mouse model with cardiac-specific overexpression of constitutively active TGFβ, which develop extensive atrial fibrosis and inducible AF, we showed that TXNDC5 was strongly upregulated in the fibrotic atria of α-MHC-TGFβcys33ser mice and specifically enriched in collagen-secreting atrial fibroblasts. Targeted deletion of TXNDC5 (Txndc5−/−) in α-MHC-TGFβcys33ser mice considerably mitigated the extent of atrial fibrosis. In addition, transesophageal atrial burst pacing induced AF in 75% (3 out of 4) α-MHC-TGFβcys33ser mice, whereas knockout of Txndc5 markedly reduced the inducibility of AF (25%, 3 out of 12) in α-MHC-TGFβcys33ser mice (Figure).

TXNDC5 KO Reduces AF Inducibility

Conclusion

The present study revealed that ER protein TXNDC5 augments atrial fibrosis by promoting cardiac fibroblast proliferation and ECM protein production via JNK signaling activation. Targeted deletion of Txndc5 protects against TGFβ induced atrial fibrosis and AF. Targeting TXNDC5, therefore, could be a promising new therapeutic approach to treat or prevent atrial fibrosis and AF.

[Prevalence of cataract among the population aged 50 years and over at different altitudes in Gansu Province]

Objective: To assess the prevalence and influence factors of cataract at different altitudes in Gansu Province. Methods: A total of 7 560 permanent residents aged 50 years and over in seven regions of Gansu Province (altitude, 900 meters to 3 500 meters) were selected as subjects, including 2 402 males and 5 158 females, with an average age of 62.04 years. The cluster random sampling method was used to conduct the survey at village or township health service centers. The investigation procedure included questionnaire survey, pre-investigation, visual acuity examination, intraocular pressure measurement, slit lamp microscopy and fundus examination. The diagnostic criterion for cataract was typical opacity of the lens or no other eye diseases that led to visual impairment but with visual acuity less than 0.7. The prevalence of cataract was calculated according to factors such as altitude, age and sex. The Chi-square test and two-element unconditional logistic regression were used for statistical analyses. Results: A total of 7 560 people were surveyed. The prevalence rate of cataract was 39.7%, and the age-standardized prevalence was 37.7%. The prevalence of cataract increased with age (χ(2)=2 107.19, P<0.01). It was 14.1% in the group of 50-59 years, 42.9% in the group of 60-69 years and 79.2% in the group of over 70 years. The prevalence of cataract also increased with altitude (χ(2)=33.66, P<0.01). It was 36.9% in the group of altitude less than 1 000 meters, 39.0% in the group of altitude between 1 000 meters and 1 999 meters, 45.9% in the group of altitude between 2 000 meters and 2 999 meters, and 51.5% in the group of altitude more than 3 000 meters. With age stratification, the prevalence of cataract at high altitude was higher than that at low altitude (χ(2)=26.74, 16.06, P<0.01). Multivariate regression analysis showed that the risk of cataract was higher in subjects at altitude of 2 000-2 999 meters than those below 1 000 meters (OR=1.42, 95%CI 1.11-1.82), and even higher in those at altitude of 3 000 meters (OR=1.76, 95%CI 1.01-3.06). Conclusions: High altitude and old age are important risk factors for cataract, and high altitude is an independent risk factor for cataract. It is necessary for local health institutions to take measures to reduce the prevalence of blindness and low vision, especially the blindness caused by cataract. (Chin J Ophthalmol, 2019, 55:589-594).

Risk factors for Barrett's esophagus in young adults who underwent upper gastrointestinal endoscopy in a health examination center

BACKGROUND

Barrett's esophagus (BE) is a premalignant condition with increased incidence worldwide both in old and young individuals. However, the role of certain potential risk factors remains unclear in young adults (< 50 years). We aimed to determine the risk factors of BE in young adults.

METHODS

A total of 4943 young adults who underwent upper gastrointestinal endoscopy at our health check-up center were enrolled. The diagnosis of BE was based on histological confirmation. We analyzed demographic factors, laboratory data, potential risk factors such as smoking, alcohol consumption, presence of gastroesophageal reflux disease (GERD) symptoms, and metabolic syndrome for the risk of BE by using binary logistic regression analysis.

RESULTS

The prevalence of BE was 1.8% (88/4943). Male sex, the presence of GERD symptoms, and smoking were three significant risk factors related to BE. Furthermore, participants who had smoked for 10 pack-years or more had increased risk of BE with dose-dependent phenomenon (p trend < 0.001). The proportion of BE in male participants with both GERD symptoms and a smoking history of 10 pack-years or more was as high as 10.3% (16/155).

CONCLUSIONS

Significant risk factors of BE in young adults are male sex, the presence of GERD symptoms, and smoking. The risk also increases with an increase in cumulative exposure to smoking.

Prevalence and risk factors for colonization by extended-spectrum β-lactamase-producing or ST 131 Escherichia coli among asymptomatic adults in community settings in Southern Taiwan

Purpose: Fecal carriage of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) is common in Asia, especially in China and Southeast Asia. There are no data about fecal carriage of ESBL-EC and mcr-1-positive E. coli in Taiwan, and few studies focusing on the risk factors of asymptomatic fecal carriage of epidemic ST131 E. coli have been published.

Patients and methods: From healthy inhabitants attending health examinations at a medical center in southern Taiwan in 2017, we collected 724 stool samples, which were examined for ESBL-EC fecal carriage using chromogenic medium. ST131 and mcr1-positive E. coli were also investigated using multiplex PCR. Clinical data from all participating adults were collected to analyze the risk factors for fecal ESBL-EC or ST131 E. coli carriage.

Results: The prevalence rate of asymptomatic ESBL-EC fecal carriage in adults was 1.9% (14/724). ST131 was found in 22 (3.0%) adults and mcr-1-positive E. coli was found in three (0.4%) adults. A multivariate analysis showed that the risk factors associated with ESBL-EC carriage were diabetes mellitus (adjusted odds ratio [aOR]: 5.5, 95% confidence interval [CI]: 1.3–22.7), a history of colonic polyps (aOR: 6.4, 95% CI: 1.6–24.9), and chronic renal insufficiency (aOR: 20.7, 95% CI: 1.4–305.7). Underlying cancer (aOR: 4.8, 95% CI: 1.0–22.5) and stroke (aOR: 18.0, 95% CI: 1.6–207.5) were associated with ST131 E. coli fecal carriage. In our cohort, travel to Asian countries and food habit were not associated with ST131 or ESBL-EC fecal carriage.

Conclusions: The ESBL-EC or ST131 E. coli fecal carriage rate is low among asymptomatic adults in Taiwan. Certain underlying medical conditions were associated with their fecal carriage.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

Gender Differences in Outcome of an Attempt to Stop Smoking Among Smokers Attending a Smoking Cessation Clinic in Taiwan: 3-Year Follow-Up Study

Studies that have examined gender differences in smoking cessation have produced mixed results. The purpose of the study was to examine whether there are gender differences in long-term smoking abstinence rates in smokers treated with nicotine patches at a smoking cessation clinic in Taiwan, where 39% of men and 5% of women smoke. This study included 1,065 smokers, comprising of 940 men and 125 women. Smokers were invited to attend the clinic every 1-2 weeks for a maximum of eight visits over 90 days, where they received prescriptions for nicotine patches, counseling, and educational materials. Participants were contacted by telephone at 1 and 3 years after the first visit and were asked whether they had smoked at all over the past 7 days. The results showed that women were significantly less likely than men to be abstinent at 1 year (adjusted odds ratio [aOR] = 0.64; 95% CI [confidence interval] = [0.41, 0.99]; p = .044) and 3 years (aOR = 0.44; 95% CI = [0.27, 0.74]; p = .02). More effective ways are needed to help female smokers quit in societies where smoking in women is rare and may be associated with social stigma.

A flat lens with tunable phase gradient by using random access reconfigurable metamaterial

The first demonstration of an optofluidic metamaterial is reported where resonant properties of every individual metamolecule can be continuously tuned at will using a microfluidic system. This is called a random-access reconfigurable metamaterial, which is used to provide the first demonstration of a tunable flat lens with wavefront-reshaping capabilities.

Prevotella brain abscesses and stroke following dental extraction in a young patient: a case report and review of the literature

A brain abscess is a life-threatening infection. There are few reports describing Prevotella bacteremia with middle cerebral artery (MCA) occlusion and brain abscess following dental extraction in the literature. We herein describe a 32-year-old healthy man who experienced headache after tooth extraction. He was not correctly diagnosed until he experienced a stroke and a blood culture revealed Prevotella denticola weeks later. This case and our detailed review of related cases highlight the importance of thorough medical history-taking and clinical evaluations. Brain abscess formation should be considered in previously healthy patients with fever, stroke, and a recent history of tooth extraction.

Complete response after MAID treatment for advanced primary ovarian angiosarcoma: case report and literature review

The patient presented in this case report was a 45-year-old female, with a Stage IIIA ovarian angiosarcoma combined with mature teratoma, that underwent debulking surgery and achieved complete remission for 11 months after six cycles of MAID chemotherapy (mesna, adriamycin/doxorubicin, ifosfamide, and dacarbazine). Thereafter, she had tumor recurrence with peritoneal seeding and massive pleural effusion; hence she received chemotherapy again. Although she had been undergoing a series of chemotherapies, the tumor continued to progress. Hence, she refused further chemotherapy since September 2012. Unfortunately, she passed away in January 2013 due to severe dyspnea with wide spread tumor progression. She had the longest survival period (31 months) and complete remission period than the other advanced primary ovarian angiosarcoma cases ever reported in the literature.

Accelerated cellular senescence in solid tumor therapy

Accelerated cellular senescence (ACS) is an emerging concept that implicates sustained, telomere-independent cell cycle arrest of neoplastic cells in response to chemotherapeutic agents, ionizing radiation, oxidative stress, or the presence of selective oncogenic stimuli. Recent evidence suggests that a subset of tumor cells induced in a state of reversible ACS can escape cell cycle arrest and resume proliferation accounting for cancer progression. The purpose of this review is to describe our current understanding of ACS including signaling pathways of senescence escape, role of senescence biomarkers, and rationale for senescence-based therapy. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".

A 24.2-Mb deletion of 4q12 --> q21.21 characterized by array CGH in a 131/2-year-old girl with short stature, mental retardation, developmental delay, hyperopia, exotropia, enamel defects, delayed tooth eruption and delayed puberty

We report molecular and cytogenetic characterization of proximal deletion of chromosome 4q, del(4)(q12 --> q21.21) in a 131/2-year-old girl with short stature, mental retardation, developmental delay, hyperopia, exotropia, enamel defects, delayed tooth eruption and delayed puberty. We speculate that haploinsufficiency of the AMTN, ENAM and AMBN genes is most likely responsible for dental disorders, haploinsufficiency of the BMP2K genes is most likely responsible for ocular disorders, and haploinsufficiency of the EREG, AREG and BTC genes is most likely responsible for delayed puberty in this patient.

Schottky junction photovoltaic devices based on CdS single nanobelts

Schottky junction photovoltaic (PV) devices were fabricated on single CdS nanobelts (NBs). Au was used as the Schottky contact, and In/Au was used as the ohmic contact to CdS NB. Typically, the Schottky junction exhibits a well-defined rectifying behavior in the dark with a rectification ratio greater than 10(3) at +/- 0.3 V; and the PV device exhibits a clear PV behavior with an open circuit photovoltage of about 0.16 V, a short circuit current of about 23.8 pA, a maximum output power of about 1.6 pW, and a fill factor of 42%. Moreover, the output power can be multiplied by connecting two or more of the Schottky junction PV devices, made on a single CdS NB, in parallel or in series. This study demonstrates that the 1D Schottky junction PV devices, which have the merits of low cost, easy fabrication and material universality, can be an important candidate for power sources in nano-optoelectronic systems.

Percutaneous Absorption of Captopril from Hydrophilic Cellulose Derivatives Through Excised Rabbit Skin and Human Skin

The purpose of this investigation was to evaluate the influence of percutaneous absorption of captopril from hydrophilic cellulose derivatives gel bases (carboxymethylcellulose sodium [CMC], hydroxypropylcellulose [HPC] and hydroxylpropylmethylcellulose [HPMC]. The effects of various types and concentrations of penetration enhancers on captopril percutaneous absorption from HPC gel through rabbit skin were evaluated and selected to obtain some optimal formulations for penetration study through human chest skin. Then the required flux (1488 microg/hr) for captopril transdermal drug delivery system to maintain the therapeutic minimum effective concentration through human skin was used to evaluate the development of the optimal formulations. The results indicated that the minimum administered areas for therapeutic minimum effective concentration of captopril (cap) gel containing decanol (dec) were 10.4 cm2 (5% cap, 7% dec) and 7.6 cm2 (7% cap, 7% dec). These areas were within acceptable range, so these formulations can possibly be developed for a transdermal drug delivery system.

Kinetics and hydrolysis mechanism of polymeric prodrugs containing ibuprofen, ketoprofen, and naproxen as pendent agents

Polymeric prodrugs were prepared using methacrylic acid (MA) copolymerization with 2-hydroxyethyl methacrylate (HEMA), covalently linked with ibuprofen (HI), ketoprofen (HK), or naproxen (HN). It was previously shown that the acceptable composition of drug-linked monomer in polymeric prodrugs to prevent gastric mucosa irritation and maintain water solubility was in the range of 20-40 mol%. To investigate the applicability of these polymeric prodrugs, hydrolysis rates of HK-25, HN-29, and HI-30 (the number indicates the mole percent of the drug-linked monomers in the polymeric prodrugs), were studied in vitro with or without esterase. The polymeric prodrugs released a major fraction of the parent drugs and a fraction of the hydroxyethyl ester drug derivatives (drug-EtOH). The calculated hydrolysis rate constants and results correlated to the drug structural solubility and steric hindrance are discussed. The anti-inflammatory properties of these polymeric prodrugs were evaluated using carrageenan-induced edema test. The results indicate that HK-25 and HN-29 display greater potency to inhibit acute inflammatory processes than the free drugs over long periods. HI-30, however, retains a potency comparable to that of free ibuprofen.

Improved antitumor response to isolated limb perfusion with tumor necrosis factor after upregulation of endothelial monocyte-activating polypeptide II in soft tissue sarcoma

BACKGROUND

Experiments with tumor necrosis factor alpha (TNF) in rodents have shown that a high dose can lead to hemorrhagic necrosis in tumors. Endothelial monocyte-activating polypeptide II (EMAP-II) is a novel tumor-derived cytokine, and its expression increases the TNF-1 receptor on tumor endothelium, enhances the induction of tissue factor on tumor endothelial cells, and has an antiangiogenic effect. It has recently been shown that in vivo sensitivity of tumor vasculature to TNF is determined by tumor production of EMAP-II.

METHODS

We measured the level of EMAP-II in a TNF-resistant soft tissue sarcoma. We subsequently stabile-transfected this cell line with a retroviral construct containing the EMAP gene. In an extremity perfusion model in tumor-bearing rats, we measured response rates to TNF therapy.

RESULTS

Functional EMAP-II production was increased after this transfection. Immunostaining of paraffin-embedded tumor tissue sections in rats showed an overexpression of human EMAP-II. Results of the TNF perfusions in rats suggest that this tumor is more sensitive to TNF therapy.

CONCLUSIONS

EMAP-II is produced in various levels. One can increase the sensitivity of tumor for TNF therapy in vivo by upregulating the EMAP-II production. This result leaves an opportunity for enhanced TNF response of tumors in future settings.

Expression of c-Myc, c-Fos, and c-jun in hepatocellular carcinoma

BACKGROUND

Increased expression of the proto-oncogene c-myc is a common phenomenon in hepatocellular carcinoma (HCC). The proto-oncogenes c-fos and c-jun are involved in cell cycle progression and cellular proliferation.

METHODS

The objective of this study was to elucidate the mechanism of hepatocarcinogenesis with regard to the expressions of c-myc, c-fos, and c-jun. One hundred fifty biopsied HCC specimens were stained immunohistochemically for the above phenotypic markers both in tumor tissue and in adjacent nontumor tissue.

RESULTS

Although the expression of c-myc was high (74%) in tumor tissue, it was significantly less compared with the expression in nontumor tissue (100%; P = 0.0002). The expression of c-myc was inversely proportional to the grade of differentiation in tumor tissue (P = 0.0108; correlation coefficient [r] = -0.244); that is, tissue with poorer histologic differentiation had a lower level of c-myc expression. There were inverse associations between the expression of c-myc and the expression of mutated p53 (P = 0.0017; r = -0.285) as well as the expression of Ki67 (P = 0.057; r = -0.147). There was significantly high expression of c-fos in tumor tissue compared with the expression in nontumor tissue (91% vs. 0%; P < 0.0001). Both the tumor tissue and the nontumor tissue had high levels of expression of c-jun (96.53% and 100%, respectively). There was a trend toward a positive association between the expression of c-fos and the expression of c-jun in tumor tissue (P = 0.07; r = 0.162).

CONCLUSIONS

Because c-myc is a known inducer of wild type p53, decreased c-myc expression may lead to uncontrolled cell growth because of the lack of p53 expression that normally induces apoptosis. The coordinated expression of c-fos and c-jun in HCC may reflect the coordinated tumor cell cycle of progression and proliferation; however, future studies are required to elucidate this possibility.

Expression of c-Myc, c-Fos, and c-jun in hepatocellular carcinoma

BACKGROUND

Increased expression of the proto-oncogene c-myc is a common phenomenon in hepatocellular carcinoma (HCC). The proto-oncogenes c-fos and c-jun are involved in cell cycle progression and cellular proliferation.

METHODS

The objective of this study was to elucidate the mechanism of hepatocarcinogenesis with regard to the expressions of c-myc, c-fos, and c-jun. One hundred fifty biopsied HCC specimens were stained immunohistochemically for the above phenotypic markers both in tumor tissue and in adjacent nontumor tissue.

RESULTS

Although the expression of c-myc was high (74%) in tumor tissue, it was significantly less compared with the expression in nontumor tissue (100%; P = 0.0002). The expression of c-myc was inversely proportional to the grade of differentiation in tumor tissue (P = 0.0108; correlation coefficient [r] = -0.244); that is, tissue with poorer histologic differentiation had a lower level of c-myc expression. There were inverse associations between the expression of c-myc and the expression of mutated p53 (P = 0.0017; r = -0.285) as well as the expression of Ki67 (P = 0.057; r = -0.147). There was significantly high expression of c-fos in tumor tissue compared with the expression in nontumor tissue (91% vs. 0%; P < 0.0001). Both the tumor tissue and the nontumor tissue had high levels of expression of c-jun (96.53% and 100%, respectively). There was a trend toward a positive association between the expression of c-fos and the expression of c-jun in tumor tissue (P = 0.07; r = 0.162).

CONCLUSIONS

Because c-myc is a known inducer of wild type p53, decreased c-myc expression may lead to uncontrolled cell growth because of the lack of p53 expression that normally induces apoptosis. The coordinated expression of c-fos and c-jun in HCC may reflect the coordinated tumor cell cycle of progression and proliferation; however, future studies are required to elucidate this possibility.

Simultaneous optimization based on artificial neural networks in ketoprofen hydrogel formula containing O-ethyl-3-butylcyclohexanol as percutaneous absorption enhancer

The influence of the amounts of additives including 1-O-ethyl-3-n-butylcyclohexanol (OEBC), diisopropyl adipate (DIA), and isopropanol (IPA) on the penetration rate (R(p)) of ketoprofen from hydrogels through rat skin in vivo was investigated. Skin irritation evoked by the application of hydrogels was evaluated based on a microscopic observation of skin cross-sections. Both optimization techniques incorporating an artificial neural network (ANN) and a second-order polynomial regression analysis were applied to the optimization of ketoprofen hydrogel formulations. Findings indicated that the R(p) and total irritation score (TIS) of the skin were predicted quantitatively as a function of quantities of OEBC, DIA, and IPA, employing ANN. In contrast, the prediction ability of the polynomial regression equation was somewhat poorer compared with that of ANN. The observed results of R(p) and TIS in the optimal formulation coincided well with the predictions in the simultaneous optimization technique incorporating ANN.

Evaluation of percutaneous absorption and skin irritation of ketoprofen through rat skin: in vitro and in vivo study

The influences of different mechanisms of penetration enhancers (such as menthol, azone, ethanol and nonivarnide) regarding the percutaneous absorption and skin irritation of ketoprofen formulations through rat skin were investigated by in vitro and in vivo study. The skin irritation degree at the end of the experiment (10 h) was deterinined by pathologic biopsy and colorimetry methods. In vitro, the menthol showed the most potent enhancing effect. Furthermore, the enhancement effect of a combination of menthol and nonivamide was higher than that of their individual use alone. In vivo the formulation containing 0.05% nonivantide, 5% menthol and 20% ethanol showed a higher penetration rate and an acceptable degree of skin irritation compared to a commercial product (Formax plus gel containing 3% ketoprofen), indicating that it could be used in the clinical situation.

Extended lamivudine treatment in patients with chronic hepatitis B enhances hepatitis B e antigen seroconversion rates: results after 3 years of therapy

A study in Chinese patients with chronic hepatitis B showed that treatment with lamivudine for 1 year significantly improves liver histology and enhances hepatitis B e antigen (HBeAg) seroconversion compared with placebo. Fifty-eight patients from this 1-year study have received long-term treatment with lamivudine 100 mg; the outcome of 3 years of lamivudine is reported here. Before treatment, all patients had detectable HBeAg. HBeAg seroconversion (HBeAg-negative, anti-HBe-positive), hepatitis B virus (HBV)-DNA suppression, alanine transaminase (ALT) normalization, emergence of YMDD variant HBV, liver histology, and long-term safety were assessed. After 3 years of continuous treatment with lamivudine 100 mg daily, 40% (23 of 58) of patients achieved HBeAg seroconversion. In patients with baseline serum ALT >2 x upper limit of normal (ULN), the rate of HBeAg seroconversion was 65% (17 of 26). Median serum HBV-DNA concentrations were below the level of detection, and median ALT concentrations were within the normal range throughout 3 years of treatment. YMDD variant HBV emerged in 33 of 58 (57%) patients during the 3 years, of whom 9 (27%) achieved HBeAg seroconversion (6 after emergence of YMDD variant HBV). ALT levels and histologic scores after emergence of YMDD variant HBV did not show major deterioration. Lamivudine was well tolerated during 3 years of therapy. In conclusion, these data in Chinese patients with chronic hepatitis B show enhanced seroconversion rates with extended lamivudine treatment. Up to two thirds of patients with moderately elevated pretreatment ALT achieved HBeAg seroconversion after 3 years of therapy.

Repair of pectus excavatum deformities in children: a new perspective of treatment using minimal access surgical technique

HYPOTHESIS

Minimally invasive correction of pectus excavatum (PE) deformities of the anterior chest wall in children is safe and effective.

DESIGN

Prospective cohort study.

SETTING

Tertiary pediatric referral center.

PATIENTS

Between February 1996 and July 2000, 36 patients underwent minimally invasive repair (MIR) of PE deformities, and 6 patients had traditional Ravitch repairs (RR).

MAIN OUTCOME MEASURES

Morbidity, operating time, estimated blood loss, days to tolerating a regular diet, and length of hospital stay.

RESULTS

Thirty-six children underwent MIR for moderate to severe chest wall deformities, with a mean operative time of 1.6 hours, a mean blood loss of 22 mL, a mean time to tolerating a regular diet of 2.9 days, no intensive care unit admissions, and a mean length of hospital stay of 5.5 days. Six children had RR procedures performed for moderate to severe deformity, with a mean operative time of 5.2 hours, a mean blood loss of 222 mL, a mean time to tolerating a regular diet of 3.3 days, 2 patients admitted to the intensive care unit, and a mean length of hospital stay of 4.5 days. Complications for both procedures consisted mainly of postoperative pneumothorax.

CONCLUSIONS

The MIR technique for PE is less invasive, less morbid, and better tolerated than traditional open RR of this common pediatric chest wall deformity. Elective surgical reconstruction can be safely performed in children rather than limiting repair to only symptomatic patients with severe deformities.

Influence of electrical and chemical factors on transdermal iontophoretic delivery of three diclofenac salts

The aim of this present study was to investigate the in vitro transdermal iontophoretic delivery of three diclofenac salts--diclofenac sodium (DFS), diclofenac potassium (DFP), and diclofenac diethylammonium (DFD). A series of physicochemical and electrical variables which might affect iontophoretic permeation of diclofenac salts was studied. Application of 0.3 mA/cm2 current density significantly increased the transdermal flux of diclofenac salts as compared to passive transport. The iontophoretic enhancement increased in the order of DFS>DFP>DFD. The permeability coefficient of diclofenac salts all decreased with increasing donor concentration during iontophoresis. The addition of buffer ions and salt ions such as NaCl, KCl, and C4H12ClN reduced the permeation of diclofenac salts due to competition. However, this effect was lesser for DFD than for DFS and DFP. Comparing the various application modes of iontophoresis, the discontinuous on/off mode showed lower but more constant flux than the continuous mode.

In vitro skin permeation of estradiol from various proniosome formulations

The skin permeation of estradiol from various proniosome gel formulations across excised rat skin was investigated in vitro. The encapsulation efficiency and size of niosomal vesicles formed from proniosomes upon hydration were also characterized. The encapsulation (%) of proniosomes with Span surfactants showed a very high value of about 100%. Proniosomes with Span 40 and Span 60 increased the permeation of estradiol across skin. Both penetration enhancer effect of non-ionic surfactant and vesicle-skin interaction may contribute to the mechanisms for proniosomes to enhance estradiol permeation. Niosome suspension (diluted proniosomal formulations) and proniosome gel showed different behavior in modulating transdermal delivery of estradiol across skin. Presence or absence of cholesterol in the lipid bilayers of vesicles did not reveal difference in encapsulation and permeation of the associated estradiol. The types and contents of non-ionic surfactant in proniosomes are important factors affecting the efficiency of transdermal estradiol delivery.

Fungal exposure of children at homes and schools: a health perspective

The authors investigated airborne fungal exposure of Taiwanese children at homes and schools-locations where they spent the majority of their time. Pairs of asthmatic and healthy children, matched by age, gender, classes (schools), and residence, participated in the study. Airborne fungal concentrations at homes and schools, and time-activity data of the study subjects were collected. In winter, the indoor geometric mean concentration was 9,672.1 colony-forming units per cubic meter and 4,380.9 colony-forming units per cubic meter in summer. The indoor/outdoor concentration ratio was similar in all homes for both seasons. Fungal concentrations in southern Taiwan were high during both winter and summer. Personal fungal exposure was not statistically different between asthmatic and nonasthmatic children, after adjustment of time-activity patterns. Higher symptom scores were shown for children in homes with higher fungal exposures.

Exposure assessment of indoor allergens, endotoxin, and airborne fungi for homes in southern Taiwan

This study was undertaken to examine the seasonal variations of domestic Der p 1, Der p 2, and endotoxin on mattress and airborne fungal concentrations in homes of asthmatic and nonasthmatic children in southern Taiwan, where temperature and relative humidity are usually high throughout the year. A group of asthmatic children (10-12 years old) were selected randomly based on a citywide questionnaire survey. The nonasthmatic children were chosen to be in the comparison group by matching in age, gender, and proximity of residence. Environmental sampling of domestic microbes was conducted once a month for a year. Twelve calendar months were grouped into spring, summer, fall, and winter according to weather data (mainly average temperature and humidity) from the Central Weather Bureau. Dust samples from a child's mattress and airborne samples from a child's bedroom were collected and analyzed for allergens of Der p 1 and Der p 2, endotoxin, and fungi respectively. Results show that about 65% of children's mattresses in our region have Der p 1 levels greater than 2 microg/g. It is also apparent that most airborne fungal concentrations found in homes of either asthmatic or nonasthmatic children are higher than the recommended levels of concern. The predominant genera are Cladosporium, Aspergillus, Penicillium, Alternaria, and yeast. In addition, seasonal effects seem to be a critical factor for the concentrations and distributions of domestic endotoxin in these study homes. The implication of long-term exposure to these high levels of environmental microbes and how their effects vary with seasons remain to be further characterized.

Expression of c-Myc, c-Fos, and c-jun in hepatocellular carcinoma

BACKGROUND

Increased expression of the proto-oncogene c-myc is a common phenomenon in hepatocellular carcinoma (HCC). The proto-oncogenes c-fos and c-jun are involved in cell cycle progression and cellular proliferation.

METHODS

The objective of this study was to elucidate the mechanism of hepatocarcinogenesis with regard to the expressions of c-myc, c-fos, and c-jun. One hundred fifty biopsied HCC specimens were stained immunohistochemically for the above phenotypic markers both in tumor tissue and in adjacent nontumor tissue.

RESULTS

Although the expression of c-myc was high (74%) in tumor tissue, it was significantly less compared with the expression in nontumor tissue (100%; P = 0.0002). The expression of c-myc was inversely proportional to the grade of differentiation in tumor tissue (P = 0.0108; correlation coefficient [r] = -0.244); that is, tissue with poorer histologic differentiation had a lower level of c-myc expression. There were inverse associations between the expression of c-myc and the expression of mutated p53 (P = 0.0017; r = -0.285) as well as the expression of Ki67 (P = 0.057; r = -0.147). There was significantly high expression of c-fos in tumor tissue compared with the expression in nontumor tissue (91% vs. 0%; P < 0.0001). Both the tumor tissue and the nontumor tissue had high levels of expression of c-jun (96.53% and 100%, respectively). There was a trend toward a positive association between the expression of c-fos and the expression of c-jun in tumor tissue (P = 0.07; r = 0.162).

CONCLUSIONS

Because c-myc is a known inducer of wild type p53, decreased c-myc expression may lead to uncontrolled cell growth because of the lack of p53 expression that normally induces apoptosis. The coordinated expression of c-fos and c-jun in HCC may reflect the coordinated tumor cell cycle of progression and proliferation; however, future studies are required to elucidate this possibility.

Evaluation of pharmacokinetics and pharmacodynamics of captopril from transdermal hydrophilic gels in normotensive rabbits and spontaneously hypertensive rats

The purpose of this investigation was to assess the pharmacokinetics (plasma concentration) and pharmacodynamics (heart rate, blood pressure (BP), and plasma renin activity (PRA)) of captopril experimental gel in normotensive rabbits and spontaneously hypertensive rats (SHRs) by reference to a short duration intravenous administration of the drug. In normotensive rabbits, the blood concentration versus time course of captopril after transdermal administration could be described well by a two-compartment model, and the maximum plasma concentration (5. 68+/-2.05 microg ml(-1)) was achieved in about 7 h. The increase in plasma captopril concentration led to increases in PRA and reductions in BP. A simple E(max) model adequately described the relationship between the percentage change of mean blood pressure (MBP) and the blood concentration of the captopril. The maximum reduction in MBP (E(max)) was 36.23% and the concentration at half maximum effect (EC(50)) was 0.24 microg ml(-1). The captopril was continuously released from the gel formulation and protected the SHRs in lower BP throughout the period of transdermal therapy. These results indicated that the development of captopril transdermal drug delivery system was possible. Further research was warranted on a modified formulation of captopril, which was optimized for transdermal delivery of the drug.

Passive and iontophoretic delivery of three diclofenac salts across various skin types

The in vitro permeation of three diclofenac salts--diclofenac sodium (DFS), diclofenac potassium (DFP) and diclofenac diethylammonium (DFD)-across skin by both passive and iontophoretic transport were investigated. Various skin types were used as the barriers to elucidate the mechanism controlling transdermal delivery of diclofenac salts. The importance of the intercellular (paracellular) route for both DFS and DFP in passive permeation was elucidated. The transfollicular route constitutes an important permeation pathway for DFS but not for DFP. The route and mechanism for transdermal iontophoresis of DFD across the skin was somewhat different to that of the other salts. Hair follicles may be a more important pathway for DFD than for DFS and DFP under iontophoresis, while the intercellular lipid pathway showed the opposite result. Combination of iontophoresis and a penetration enhancer, cardamom oil, did not show a synergistic effect on diclofenac salt permeation. The results of this investigation suggest that the transdermal mechanism and the route of diclofenac salt uptake via passive and iontophoretic transport can be affected by their counterions.

Hemophilia B with mutations at glycine-48 of factor IX exhibited delayed activation by the factor VIIa-tissue factor complex

Gly-48 is in the conserved DGDQC sequence (residues 47-51 of human factor IX) of the first EGF (EGF-1)-like domain of factor IX. The importance of the Gly-48 is manifested by two hemophilia B patients; factor IXTainan and factor IXMalmo27, with Gly-48 replaced by arginine (designated IXG48R) and valine (IXG48V), respectively. Both patients were CRM+ exhibiting mild hemophilic episodes with 25% (former) and 19% (latter) normal clotting activities. We characterize both factor IX variants to show the roles of Gly-48 and the conservation of the DGDQC sequence in factor IX. Purified plasma and recombinant factor IX variants exhibited approximately 26%-27% normal factor IX's clotting activities with G48R or G48V mutation. Both variants depicted normal quenching of the intrinsic fluorescence by increasing concentrations of calcium ions and Tb3+, indicating that arginine and valine substitution for Gly-48 did not perturb the calcium site in the EGF-1 domain. Activation of both mutants by factor XIa appeared normal. The reduced clotting activity of factors IXG48R and IXG48V was attributed to the failure of both mutants to cleavage factor X: in the presence of only phospholipids and calcium ions, both mutants showed a 4 to approximately 7-fold elevation in Km, and by adding factor VIIIa to the system, although factor VIIIa potentiated the activation of factor X by the mutants factor IXaG48R and factor IXaG48V, a 2 to approximately 3-fold decrease in the catalytic function was observed with the mutant factor IXa's, despite that they bound factor VIIIa on the phospholipid vesicles with only slightly reduced affinity when compared to wild-type factor IXa. The apparent Kd for factor VIIIa binding was 0.83 nM for normal factor IXa, 1.74 nM for IXaG48R and 1.4 nM for IXaG48V. Strikingly, when interaction with the factor VIIa-TF complex was examined, both mutations were barely activated by the VIIa-TF complex and they also showed abnormal interaction with VIIa-TF in bovine thromboplastin-based PT assays. Taken together, our results suggest that mutations at Gly-48 altered the interaction of factor IX with its extrinsic pathway activator (VIIa-TF complex), its macromolecular substrate (factor X), and its cofactor (factor VIIIa).

Tumour necrosis factor receptor I (p55) is upregulated on endothelial cells by exposure to the tumour-derived cytokine endothelial monocyte- activating polypeptide II (EMAP-II)

Endothelial monocyte activating polypeptide-II (EMAP-II) is an inflammatory cytokine known to have a role in neutrophil and macrophage chemotaxis and in apoptosis. It is a tumour-derived cytokine that sensitizes tumour vasculature to the effects of systemic TNF. In order to gain insight into the mechanism by which EMAP-II sensitizes vessels to TNF, we focused on its effects on TNF receptor expression. In human umbilical vein endothelial cells (HUVEC), TNF-R1 mRNA is increased four-fold following incubation with recombinant EMAP-II. Conditioned media from cell lines known to produce high levels of EMAP-II upregulated TNF-R1 but not TNF-R2 by up to twenty-fold compared to media controls and low expressing cell lines; this effect was blocked by anti-EMAP-II antibody. Recombinant EMAP-II upregulated TNF-R1 expression by approximately six-fold. Analysis of HUVEC lysates by ELISA showed increased expression of TNF-R1 within 2 h; TNF-R2 expression was unaffected by recombinant EMAP-II. Finally, immunohistochemistry of human melanomas in vivo showed that TNF-R1 staining is increased on the vessels of tumours known to express high levels of EMAP-II compared to low EMAP-II expressing tumours. These results suggest that EMAP-II upregulates TNF-R1 expression by endothelial cells both in vitro and in vivo. This induction of TNF-R1 expression may be the mechanism by which EMAP-II sensitizes tumour endothelium to the effects of TNF leading to haemorrhagic necrosis.

Induction of cell proliferation arrest and apoptosis in hepatoma cells through adenoviral-mediated transfer of p53 gene

BACKGROUND/AIM

Loss of p53 function is common in hepatocellular carcinoma and is associated with an extremely poor prognosis. The aim of the study was to evaluate the biologic effect of adenoviral-mediated gene transfer of wild-type p53 gene in four hepatoma cell lines with different p53 genetic makeup.

METHODS

Recombinant adenovirus expressing wild-type p53 was used. Recombinant adenoviruses with either an empty expression cassette or expressing beta-galactosidase gene served as controls.

RESULTS

High-level expression of wild-type p53 was achieved with adenoviral-mediated gene transfer. The expressed p53 protein showed nuclear localization and its expression was associated with an induction of p21 and bax expression. Expression of the p53 gene was associated with inhibition of tumor cell proliferation and induction of apoptosis. Expression of p53 was also associated with an upregulation of CD95 (Apo-1/Fas) gene expression, which may predispose the tumor cells to undergo apoptosis induced by the Fas Ligand/Fas cytolytic pathway. An additional anti-tumor effect, in terms of allowing the replication-defective adenovirus to replicate, was observed in hepatoma cells with homozygous deletion of p53 genes and to a lesser extent, hepatoma cells with mutated p53 genes.

CONCLUSIONS

These data showed that adenoviral-mediated gene transfer is effective in delivering p53 gene to tumor cells, and the multiple pathways involved in their antitumor activities.

A comparison of sampling media for environmental viable fungi collected in a hospital environment

Quantitative evaluation of fungal exposure is often conducted by analysis of the composition of microbes in air samples and calculation of the concentrations afterward. The collecting medium that favors the growth for most saprophytic fungi is considered to be the ideal choice in most circumstances. Currently, the culture medium most frequently adopted in environmental sampling for airborne fungi is MEA (malt extract agar) recommended by the ACGIH for its suitability for most fungal growth. DG18 (dichloran glycerol-18), developed in 1980, is suggested for growth at lower water activity (a(w)=0.95) specifically and is not as commonly used in general studies. This investigation collected airborne viable fungi using a single stage/N6 Andersen impactor with MEA and DG18 agar plates attached simultaneously to the same set of samplers. The sampling locations were at 17 sites within a central air-conditioned hospital. After incubation and morphological identification, concentrations of airborne fungi and bacteria were expressed as CFU/m(3) (colony forming units/m(3)). There are 405 DG18 plates and 378 plates available for statistical analysis. Results show that the airborne fungal concentrations, shown by geometric mean (GM), are higher from the DG18 plates than from the MEA plates. The total fungal concentrations is 68.6 vs 12.94 CFU/m(3), and for Aspergillus spp., the concentration is 1.58 vs 0.72 CFU/m(3); for Penicillium spp., 3.37 vs 0.71; and for yeast, 5.09 vs 0.49 CFU/m(3). In addition, the number of different genera present is greater on the DG18 plates than on the MEA plates, on average, 2.85 types vs 1.72. This study suggests that in a hospital environment with 24-h, central air conditioning, DG18 plates appear to be more effective in collecting more fungal colonies in terms of both quantity and types of genera. Such a finding is presumed to be attributed to the characteristic of DG18 in slowing colony growth so that the dominating genus will not over occupy the culture plate surface before the less competitive genus can fully develop. Future studies on related biological mechanisms are essential to conclude whether the above results sustain when sampling is conducted in other environments.

Antituberculosis drug-related liver dysfunction in chronic hepatitis B infection

Liver toxicity is a common side effect of antituberculosis (anti-TB) drugs. We studied the differences in liver dysfunction observed during anti-TB treatment between hepatitis B virus carriers (HBV) and noncarriers. Three hundred twenty-four patients on anti-TB drugs were recruited and followed up for 1 year. Forty-three patients with HBV and 276 non-HBV patients were included for analysis. Liver function tests and viral markers were monitored monthly. Liver biopsy was requested whenever the alanine transaminase (ALT) was persistently abnormal. Eighty-six HBV carriers who were not given anti-TB drugs were chosen as a second control and evaluated prospectively. The incidence of liver dysfunction was significantly higher in HBV carriers given anti-TB drugs (34.9%) when compared to noncarriers (9.4%, P <.001) and with HBV carriers not given anti-TB drugs (8.1%, P <.001). For patients given anti-TB drugs, HBV carriers who developed liver dysfunction were younger (P =.011) and had more severe liver injury compared with noncarriers (P =.008). By multiple logistic regression analysis, age (P =.002) and hepatitis B infection (P <.001) were the only 2 significant risk factors for hepatotoxicity related to anti-TB therapy.

Isolated hepatic perfusion for lapine liver metastases: impact of hyperthermia on permeability of tumor neovasculature

BACKGROUND

Hyperthermic isolated hepatic perfusion (IHP) has been shown to cause significant regression of advanced unresectable liver metastases in patients. Although there are different agents and treatment modalities used in IHP, the contribution of perfusion hyperthermia is unknown.

PURPOSE

A large animal model of unresectable liver metastases and a technical standard for IHP in this model were established. This model was used to assess the effects of hyperthermia on vascular permeability of tumors and normal liver tissue during IHP.

METHODS

Sixty-five New Zealand White rabbits were used in a series of experiments. Disseminated liver tumors were established by direct injection of 1 x 10(6) VX-2 cells into the portal vein by laparotomy in anesthetized animals. Several surgical perfusion techniques were explored to determine a reliable and reproducible IHP model. Vascular permeability in tumor versus liver was then assessed with Evan's Blue labeled bovine albumin under normothermic (tissue temperature 36.5 degrees C +/- 0.5 degree C), moderate hyperthermic (39 degrees C +/- 0.5 degree C), or severe hyperthermic (41 degrees C +/- 0.5 degree C) conditions.

RESULTS

Tumor model and perfusion techniques were successfully established with inflow through the portal vein and outflow through an isolated segment of the inferior vena cava. A gravity driven perfusion circuit with stable perfusion parameters and complete vascular isolation was used. Vascular permeability was higher in tumor than in normal tissues (P = .03) at all time points during IHP. Hyperthermia resulted in a significant (up to 5-fold) increase in permeability of neovasculature; when severe hyperthermia was used, tumor vascular permeability was increased even more than normal liver permeability (P = .01).

CONCLUSIONS

The VX-2/New Zealand White rabbit system can be used as a reproducible large-animal model for IHP of unresectable liver metastases. It can be used to characterize the contribution and mechanism of action of different treatment parameters used in IHP. Hyperthermia preferentially increases vascular permeability in tumors compared with liver tissue in a dose-dependent fashion, thus providing a mechanism for its presumed benefit during isolated organ perfusion.

Isolated hepatic perfusion for lapine liver metastases: impact of hyperthermia on permeability of tumor neovasculature

BACKGROUND

Hyperthermic isolated hepatic perfusion (IHP) has been shown to cause significant regression of advanced unresectable liver metastases in patients. Although there are different agents and treatment modalities used in IHP, the contribution of perfusion hyperthermia is unknown.

PURPOSE

A large animal model of unresectable liver metastases and a technical standard for IHP in this model were established. This model was used to assess the effects of hyperthermia on vascular permeability of tumors and normal liver tissue during IHP.

METHODS

Sixty-five New Zealand White rabbits were used in a series of experiments. Disseminated liver tumors were established by direct injection of 1 x 10(6) VX-2 cells into the portal vein by laparotomy in anesthetized animals. Several surgical perfusion techniques were explored to determine a reliable and reproducible IHP model. Vascular permeability in tumor versus liver was then assessed with Evan's Blue labeled bovine albumin under normothermic (tissue temperature 36.5 degrees C +/- 0.5 degree C), moderate hyperthermic (39 degrees C +/- 0.5 degree C), or severe hyperthermic (41 degrees C +/- 0.5 degree C) conditions.

RESULTS

Tumor model and perfusion techniques were successfully established with inflow through the portal vein and outflow through an isolated segment of the inferior vena cava. A gravity driven perfusion circuit with stable perfusion parameters and complete vascular isolation was used. Vascular permeability was higher in tumor than in normal tissues (P = .03) at all time points during IHP. Hyperthermia resulted in a significant (up to 5-fold) increase in permeability of neovasculature; when severe hyperthermia was used, tumor vascular permeability was increased even more than normal liver permeability (P = .01).

CONCLUSIONS

The VX-2/New Zealand White rabbit system can be used as a reproducible large-animal model for IHP of unresectable liver metastases. It can be used to characterize the contribution and mechanism of action of different treatment parameters used in IHP. Hyperthermia preferentially increases vascular permeability in tumors compared with liver tissue in a dose-dependent fashion, thus providing a mechanism for its presumed benefit during isolated organ perfusion.

Isolated organ perfusion does not result in systemic microembolization of tumor cells

BACKGROUND

Isolated organ perfusion with hyperthermia and melphalan with or without tumor necrosis factor-alpha has been effectively used to treat regionally confined, unresectable malignancies of both the limb and liver. Many patients, however, will eventually relapse at distant sites. We used reverse transcription-polymerase chain reaction (RT-PCR) to determine whether significant tumor microembolization occurs in patients undergoing isolated limb perfusion (ILP), isolated hepatic perfusion (IHP), or hepatic resection.

METHODS

Primers specific for the human tyrosinase gene or carcinoembryonic antigen gene were designed for RT-PCR to screen melanoma or colon adenocarcinoma, respectively. RNA from human melanoma lines (Pmel and 1286) and human colon adenocarcinoma lines (H508 and HT29) were used to generate positive control cDNA. Normal human blood was inoculated with tumor cells at concentrations that ranged from 10(-2) to 10(5) tumor cells/ml of blood to define the sensitivity. Systemic and perfusate blood samples were drawn from 15 patients (8 patients underwent IHP, 5 patients underwent ILP, and 2 patients underwent resection) before the start of the operation, immediately before and during the perfusion, and postoperatively. Mononuclear cell fractions were separated from the blood samples and RNA was extracted for the RT-PCR assay. Standard primers for human beta-actin were used to confirm that cDNA was generated after the RT reaction.

RESULTS

RT-PCR assay sensitivity was determined to be 10 tumor cells/ml of whole blood. Of the 8 IHP patients, 6 had colon metastases and 2 had ocular melanoma metastases to the liver. All 5 ILP patients had in transit melanoma of the extremity. Two patients with colon metastases to the liver were found to have resectable disease. There were no detectable circulating tumor cells in the systemic circulation either preoperatively or postoperatively in all 15 patients that were screened.

CONCLUSIONS

RT-PCR is a highly sensitive method of detecting tumor cells in perfusate or blood. Manipulation of the limb or liver followed by resection or isolated hyperthermic perfusion does not cause detectable release of circulating tumor cells. The late development of distant metastases observed in many of these patients does not correlate with the ability to measure circulating tumor cells during regional therapy.