[Analysis and prediction of disease burden of cirrhosis and other chronic liver diseases due to alcohol use in China from 1990 to 2030]

Objective: To comprehensively understand the disease burden of liver cirrhosis and other chronic liver diseases caused by alcohol use in China from 1990 to 2019, as well as to predict the trends in disease burden from 2020 to 2030. Methods: The analysis utilized data from the Global Burden of Disease study in 2019 (GBD2019). Key indicators such as incidence rate, mortality rate, disability-adjusted life years (DALY), years of life lost due to premature mortality, and years lived with disability were selected to describe the disease burden of alcohol-related liver cirrhosis and other chronic liver diseases in China from 1990 to 2019. The estimated annual percentage change (EAPC) was used to depict the temporal trends in disease burden. Furthermore, a Bayesian age-period-cohort (BAPC) model was constructed using R software to predict the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) of alcohol-related liver cirrhosis and other chronic liver diseases in China from 2020 to 2030. Results: From 1990 to 2019, the incidence of alcohol-related liver cirrhosis and other chronic liver diseases in China showed an upward trend, with an EAPC of 0.31% (95%CI: 0.10%-0.52%). However, the DALY declined, with an EAPC of -2.81% (95%CI: -2.92% - -2.70%). The ASMR showed a downward trend, with an EAPC of -2.55% (95%CI: -2.66% - -2.45%). The highest incidence of cirrhosis of liver caused by alcohol and other chronic liver diseases was reported in the age group of 35-49 years, while the ASMR increased gradually with age, with a significant rise after the age of 30. The age-standardized DALY rate peaked between the ages of 55 and 64. The disease burden indicators for males were consistently higher than those for females during the same period. According to the predictions of the BAPC model, from 2020 to 2030, the ASIR for cirrhosis of liver caused by alcohol and other chronic liver diseases in the entire population of China was projected to increase from 3.45/100 000 in 2020 to 3.78/100 000 in 2030, a growth of 9.57%. Conversely, the ASMR was expected to decrease from 1.45/100 000 in 2020 to 1.24/100 000 in 2030, a reduction of 14.48%. Conclusions: The disease burden of cirrhosis of liver caused by alcohol and other chronic liver diseases remained serious in China, especially in men and the middle-aged to elderly population. There is a pressing need to prioritize attention and resources towards these groups. Despite the projected decrease in ASMR, the ASIR continued to rise and is expected to persist in its upward trend until 2030.

[Progress in research of quantification of biological age]

Biological age has been proved to be better than chronological age to measure the real difference of aging among individuals, but no consensus has been reached in the quantification of biological age in the field of aging research. In this paper, we summarize some commonly used quantification methods of biological age and discuss the its future development.

[Effects of four efflux pump inhibitors on the activities of clarithromycin against Mycobacterium abscessus]

Objective: To detect the effects of four efflux pump inhibitors on the minimum inhibitory concentration of clarithromycin (CLA) against Mycobacterium abscessus (M. abscessus) in vitro, and to explore the role of efflux pump in CLA resistance of M. abscessus. Methods: Four frequently-used efflux pump inhibitors (Carbonyl Cyanide 3-chlorophenylhydrazone, CCCP, N, N'-dicyclohexylcarbodiimide, DCC, Verapamil, VP, Reserpine, RSP) were evaluated in this study. The minimum inhibitory concentration (MIC) values of clarithromycin against M. abscessus reference strain and 60 clinical strains with or without efflux pump inhibitors were detected by Alamar Blue method. Sequence analysis of erm(41) and rrl genes known to be associated with CLA resistance in M. abscessus was performed to analyze the correlation between the effect of efflux pump inhibitors on MIC and mutation of resistance-related genes. Results: CCCP, DCC, VP and RSP could reduce the MIC of M. abscessus to CLA, and the effect of RSP was weaker than the other three efflux pump inhibitors. Among the sixty M. abscessus clinical strains, ten strains were resistant to clarithromycin, seven of which had rrl gene mutation. The CLA resistance rate of smooth phenotype isolates was higher than that of rough phenotype isolates. At 3 day of clarithromycin incubation, the MICs of resistant strains were all reduced by efflux pump inhibitors. Compared with the strains with rrl gene mutation, efflux pump inhibitors had a greater effect on the strains without rrl gene mutation. At 14 day of clarithromycin incubation, 83% of M. abscessus subsp. abscessus, were induced to be resistant, and all of them were T28 sequence type of erm(41). With the occurrence of induced drug resistance, the effect of efflux pump inhibitor on CLA MIC decreased. Efflux pump inhibitors had no statistically significant diffence in the effect of effcux pump inhibitors on CLA MIC levels in different phenotypes of isolates. Conclusions: Efflux pump is involved in the resistance process of M. abscessus to CLA. Efflux pump inhibitors reduce the drug resistance to clarithromycin against M. abscessus in different degrees. The use of efflux pump inhibitors may provide a new way to alleviate the drug resistance of M. abscessus.

[Research progress on the relationship between HIV infection, antiretroviral therapy, and diabetes mellitus]

The expectancy and quality of life among people with HIV have improved remarkably with the widespread use of antiretroviral therapy (ART). In the meantime, the risks for HIV-related metabolic diseases have increased significantly, in particular diabetes mellitus. Multi-factors coeffect to increasing the risk of diabetes mellitus among HIV patients. Recently, growing of research has reported an association between HIV infections and ART and the development of diabetes mellitus. In this article, we summarize the recent studies investigating HIV infection and ART in diabetes mellitus to clarify their mechanism on the development of diabetes.

[G methods for handling time-varying confounding in the longitudinal study]

The conventional analytical methods cannot effectively adjust for time-varying confounding that occur in a longitudinal study and thus cannot correctly estimate the causal effects. This study explains the necessity of precisely controlling time-varying confounding and outlines G methods, including parametric g-formula, inverse probability of weighting, and G-estimation. We also compare the methods above to provide a reference for correctly estimating causal effects in the longitudinal study.

[Performance of matrix assisted laser desorption ionization time of flight biotyper system in clinical bacteria identification]

Objective: To evaluate the performance of MALDI Biotyper system in identification of clinically isolated pathogens so as to provide a new rapid identification method. Methods: Total 21 270 pathogens strains, isolated from the First Affiliated Hospital of Fujian Medical Universityduring Nov. 2015 to Dec. 2016, were identified by VITEK-Ⅱ, API and MALDI Biotyper system, respectively.The isolated strains were confirmed by DNA sequencing. Results: The identification of common bacteria with MALDI Biotyper and phenotypic system is highly consistent (>95% and >90%). Among 43 strains of anaerobic bacteria, MALDI Biotyper could identify 90.7% bacteria to species level and 97.7% bacteria to genus level with the statistical significance(χ(2)=6.76, P<0.01), while phenotypic system only identified 65.1% bacteria to species and 69.8% bacteria to genus. Also, no statistical significance was shown for Trichosporon and Candida(P>0.05). MALDI Biotyper could identify 76% filamentous fungi and all of Actinomycetes, Nocardia, Mycobacterium and Legionella to genus level. Conclusions: MALDI Biotyper is an easy-performed, sensitive method for the identification of clinically isolated pathogens. Additionally, the pretreatment and reference database has the effect on identification.

Age Estimation and Age-related Facial Reconstruction of Xinjiang Uygur Males by Three-dimensional Human Facial Images

OBJECTIVES

To search age-correlated facial features and construct an age estimation model based on the three-dimensional （3D） facial images of Xinjiang Uygur males, and to structure individual face images of old age and young age.

METHODS

Pretreatment was performed to collect 105 3D facial images of Xingjiang Uygur males aged between 17-57 years by Artec Studio software. The facial images were transferred to high-density 3D dot matrix data by FaceAnalysis software, and each image could be represented with 32 251 vertexes. Central correction of the facial images was done and all the data were aligned to a standard coordinate frame by generalized Procrustes analysis （GPA）. The age estimation model was established by partial least square regression （PLSR）. Furthermore, the changes of age-correlated facial features were presented on the heat map of average face, and the reconstruction of facial images at different ages was performed based on this model.

RESULTS

With age, the average faces showed a series of changes including the nasolabial sulcus deepening, cheek sinking, cheekbone protruding and eye corner drooping. The Pearson correlation coefficient （r） between estimated age and chronological age was 0.71. The mean absolute deviation （MAD） of age estimation was 6.37 years. The results of age estimation in >30-40 years group showed a best accuracy （MAD=4.27 years）, and the deviations increased with age after 40 years. The composite facial images represented a significant result with age on facial morphological features and aging.

CONCLUSIONS

The results of this study reveal the age-correlated facial features and aging markers in Uygur population, which help to construct a reliable age estimation model.

Abstract OT2-04-01: An open label, phase II trial of continuous low-irradiance photodynamic therapy (CLIPT) using verteporfin for the treatment of cutaneous breast cancer metastases

Background

Cutaneous metastases occur in approximately 20% of patients (pts) with metastatic breast cancer (mBC) and can be highly symptomatic and distressing. Radiation therapy is frequently used, but progression often occurs quickly. Systemic therapies are also typically used, but also often result in limited benefit. Photodynamic therapy is a promising approach with encouraging results in small studies. Here we will evaluate a novel Continuous Low-Irradiance Photodynamic Therapy (CLIPT) system that emits 690nm LED via a handheld Power Pack attached to a single-use sterile Light Patch to deliver a total energy level of 20J/cm2. Verteporfin (Visudyne®) is a photosensitizer approved for ophthalmological use that, when combined with CLIPT, generates activated oxygen species which can destroy tumor cells with limited normal tissue reaction.

Methods

This open label, Phase 2 study will evaluate the efficacy and safety of CLIPT with verteporfin in 15 patients with cutaneous lesions from mBC. Patients will receive a single IV injection of Verteporfin on day 1. The 9x9cm Light Patch with an adhesive border is placed over the treatment site and attached to the CLIPT portable Power Pack. The patient turns the device on at home 6 hours after the Verteprofin injection and it automatically turns off after 24 hours. The patient then removes the Light Patch and returns to clinic on day 3. The primary endpoint is objective response rate (RR) at 3 weeks following CLIPT using a modified RECIST which accounts for nodular or diffuse plaque-like lesions. Response will be confirmed by independent dermatologist review. Secondary endpoints include RR at 2, 8 and 12 weeks, toxicity, and quality of life (using FACT-B and Brief Pain Inventory). A novel Participant Symptom Scale (PSS) will also be used in which the first 8 patients will list their most distressing symptoms from cutaneous metastases and score the severity of the symptoms from 1 to 10. The six most common symptoms among the first 8 patients will then be used in the PSS for the remaining 7 patients. The PSS will be assessed at baseline and at subsequent visits to explore any improvement in severity of symptoms after treatment with CLIPT. Patients who derive clinical benefit may be retreated up to 3 times to the same or different region. Eligible patients will have: cutaneous metastases from mBC with measurable disease by protocol defined modified RECIST 1.1, ≥ 1 line of prior systemic or local therapy for mBC, ≥ 14 days from prior systemic therapy or 60 days from radiation to target lesion, and no expectation for systemic therapy for ≥ 14 days after CLIPT. RR will be reported with 95% CI. With 15 patients, if ≥ 3 responses (RR ≥ 20%) are observed, the null hypothesis of RR ≤ 5% will be rejected. At the time of abstract submission, 4 patients have been accrued. Clinical Trials Reg: NCT02939274

Citation Format: Isakoff SJ, Rogers GS, Hill S, McMullen P, Habin KR, Chen ST, Bartenstein DW, Barry W, Overmoyer BA. An open label, phase II trial of continuous low-irradiance photodynamic therapy (CLIPT) using verteporfin for the treatment of cutaneous breast cancer metastases [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-04-01.

Drug repurposing and therapeutic anti-microRNA predictions for inhibition of oxidized low-density lipoprotein-induced vascular smooth muscle cell-associated diseases

Drug repurposing is a new method for disease treatments, which accelerates the identification of new uses for existing drugs with minimal side effects for patients. MicroRNA-based therapeutics are a class of drugs that have been used in gene therapy following the FDA's approval of the first anti-sense therapy. This study examines the effects of oxLDL on vascular smooth muscle cells (VSMCs) and identifies potential drugs and antimiRs for treating VSMC-associated diseases. The Connectivity Map (cMap) database is utilized to identify potential new uses of existing drugs. The success of the identifications was supported by MTT assay, clonogenic assay and clinical trial data. Specifically, 37 drugs, some of which are undergoing clinical trials, were identified. Three of the identified drugs exhibit IC50 activities. Among the 37 drugs' targets, three differentially expressed genes (DEGs) are identified as drug targets by using both the DrugBank and the NCBI PubChem Compound databases. Also, one DEG, DNMT1, which is regulated by 17 miRNAs, where these miRNAs are potential targets for developing antimiR-based miRNA therapy, is found.

Identify potential drugs for cardiovascular diseases caused by stress-induced genes in vascular smooth muscle cells

BACKGROUND

Abnormal proliferation of vascular smooth muscle cells (VSMC) is a major cause of cardiovascular diseases (CVDs). Many studies suggest that vascular injury triggers VSMC dedifferentiation, which results in VSMC changes from a contractile to a synthetic phenotype; however, the underlying molecular mechanisms are still unclear.

METHODS

In this study, we examined how VSMC responds under mechanical stress by using time-course microarray data. A three-phase study was proposed to investigate the stress-induced differentially expressed genes (DEGs) in VSMC. First, DEGs were identified by using the moderated t-statistics test. Second, more DEGs were inferred by using the Gaussian Graphical Model (GGM). Finally, the topological parameters-based method and cluster analysis approach were employed to predict the last batch of DEGs. To identify the potential drugs for vascular diseases involve VSMC proliferation, the drug-gene interaction database, Connectivity Map (cMap) was employed. Success of the predictions were determined using in-vitro data, i.e. MTT and clonogenic assay.

RESULTS

Based on the differential expression calculation, at least 23 DEGs were found, and the findings were qualified by previous studies on VSMC. The results of gene set enrichment analysis indicated that the most often found enriched biological processes are cell-cycle-related processes. Furthermore, more stress-induced genes, well supported by literature, were found by applying graph theory to the gene association network (GAN). Finally, we showed that by processing the cMap input queries with a cluster algorithm, we achieved a substantial increase in the number of potential drugs with experimental IC50 measurements. With this novel approach, we have not only successfully identified the DEGs, but also improved the DEGs prediction by performing the topological and cluster analysis. Moreover, the findings are remarkably validated and in line with the literature. Furthermore, the cMap and DrugBank resources were used to identify potential drugs and targeted genes for vascular diseases involve VSMC proliferation. Our findings are supported by in-vitro experimental IC50, binding activity data and clinical trials.

CONCLUSION

This study provides a systematic strategy to discover potential drugs and target genes, by which we hope to shed light on the treatments of VSMC proliferation associated diseases.

Inhibition of adipogenic differentiation of bone marrow mesenchymal stem cells by erythropoietin via activating ERK and P38 MAPK

We examined whether erythropoietin (EPO) can inhibit adipogenic differentiation of mesenchymal stem cells (MSCs) in the mouse bone marrow and its underlying mechanism. We separated and extracted mouse bone marrow MSCs and induced adipogenic differen-tiation using 3-isobutyl-1-methylxanthine, insulin, and dexamethasone. Different concentrations of EPO were added to the cells and observed by Oil Red O staining on the 20th day to quantitatively analyze the degree of cell differentiation. mRNA expression levels of peroxysome proliferator-activated receptor γ (PPARγ), CCAAT enhancer binding protein α, and adiponectin were analyzed by real-time quantitative polymerase chain reaction, and the activity of PPARγ, extracellular sig-nal-regulated kinase (ERK), and p38 mitogen-activated protein kinase (p38 MAPK) were determined by western blotting. EPO significantly inhibited adipogenic differentiation of MSCs after 20 days and reduced absorbance values by Oil Red O staining without affecting proliferation activity. EPO downregulated the mRNA expression of PPARγ, CCAAT enhancer binding protein α, fatty acid binding protein 4, and adiponec-tin during adipogenesis and increased protein phosphorylation of ERK, p38 MAPK, and PPARγ during differentiation. EPO downregulated the mRNA expression of PPARγ, CCAAT enhancer binding protein α, fatty acid binding protein 4, and adiponectin by increasing protein phosphor-ylation of ERK, p38 MAPK, and PPARγ during differentiation, which inhibited adipogenic differentiation of MSCs.

Arecoline inhibits interleukin-2 secretion in Jurkat cells by decreasing the expression of alpha7-nicotinic acetylcholine receptors and prostaglandin E2

The purpose of the present study was to explore the effect of arecoline on phytohemagglutinin (PHA)-stimulated interleukin-2 (IL-2) secretion, the expression of alpha7-nicotinic acetylcholine receptors (α7-nAChRs), prostaglandin E2(PGE2) protein, and IL-2 mRNA in human lymphocyte cells (Jurkat cell line). The IL-2 and PGE2 were determined by enzyme-linked immunosorbent assay (ELISA). The expressions of phosphorylated extracellular signal-regulated kinase (ERK) and α7-nAChRs were determined by Western blotting. The level of IL-2 mRNA was determined by reverse-transcriptase polymerase chain reaction (RT-PCR). Arecoline, in a dose-dependent manner, significantly decreased IL-2 and PGE2 secretion by Jurkat cells incubated with 0 or 5 μg/ml 5 μg/ml PHA. PGE2 also significantly inhibited IL-2 secretion by Jurkat cells in a dose-dependent manner. In addition, reduced expression of PHA-induced ERK phosphorylation was observed in Jurkat cells treated with arecoline. PHA-enhanced IL-2 mRNA expression was also inhibited by arecoline. These results imply that arecoline inhibits the release of PGE2 and PHA-induced IL-2 secretion by Jurkat cells and that these effects seem to occur, at least in part, either through the attenuation of ERK in conjunction with a decrease of PHA-induced IL-2 mRNA expression. These results imply that arecoline inhibits the protein expression of α7-nAChRs , the release of PGE2 and PHA-induced IL-2 secretion by Jurkat cells.

Nutrition knowledge, attitude and practice of teachers in rehabilitation centres in northern Malaysia

INTRODUCTION

Persons with disabilities (PWD) are susceptible to malnutrition. Caregivers or teachers in rehabilitation centres may not be adequately trained in nutrition management of PWD. The aims of this study were (i) to assess the nutrition knowledge, attitude and practice among teachers in community-based rehabilitation centres for PWD; and (ii) to evaluate changes in the nutrition knowledge and attitude of the teachers before and after exposure to a training workshop on nutrition management for PWD.

METHODS

A cross-sectional survey was conducted using a guided self-administered Nutrition Knowledge, Attitude and Practice Questionnaire on Persons with Disabilities (KAP-nOKU), among a convenience sample of 210 teachers. Forty-five of them further participated in a nutrition training workshop and completed the post-test evaluation on knowledge and attitude of the same measures.

RESULTS

At baseline, the teachers' average knowledge, attitude and practice scores were 13.80 +/- 3.73 for knowledge (below 50th percentile); 51.49 +/- 4.08 for attitude (above 75th percentile); and 48.08 +/- 3.61 for practice (between 50th and 75th percentile). There was significant positive correlations between knowledge and attitude (r=0.343, p<0.05), as well as between attitude and practice (r=0.147, p<0.05). After exposure to a 3-day nutrition workshop, significant improvements in the teachers' knowledge and attitude were observed, whereby teachers' knowledge score increased from 14.20 +/- 3.80 to 25.38 +/- 2.36 and from 51.16 +/- 3.97 to 55.20 +/- 4.41 for attitude (p<0.001).

CONCLUSION

Nutrition intervention was associated with improvement in short term knowledge and attitude of the teachers. Sustainable interventional strategies are needed to enhance the nutrition knowledge and skills of teachers of PWD.

Capsaicin may induce breast cancer cell death through apoptosis-inducing factor involving mitochondrial dysfunction

The majority of breast cancer patients are resistant to chemotherapy or radiotherapy due to the down-regulation or lack of caspase-3 expression. Capsaicin was found to inhibit cancer cell growth in caspase-3-deficient human breast cancer cells. This study aimed to investigate the growth-inhibitive effect of capsaicin and its mechanisms in human breast cancer cell lines, MCF-7 and BT-20. The results showed that cell viability decreased in a dose-dependent manner in both the caspase-3-deficient and non-deficient cells through inducing cell apoptosis and arresting the cell cycle in the S phase. Capsaicin significantly decreased mitochondria membrane potential, induced the cleavage of PARP-1, and decreased procaspase-7 expression in both cells. Apoptosis-inducing factor (AIF) was distinctly released from mitochondria and translocated into the cytoplasm and nucleus in MCF-7 cells (52.9%), but not in BT-20 cells (2%) after treatment with 200 μM of capsaicin for 24 hours. Capsaicin inhibited breast cancer cell growth through inducing cell apoptosis and cell cycle arrest in the S phase. This apoptotic effect could be induced through the mitochondrial pathway, and PARP-1 subsequently cleaved by activation of caspase-7. The application of capsaicin in clinical therapy could be useful for breast cancer patients.

Prognostic significance of triple negative breast cancer at tumor size 1 cm and smaller

AIMS

The purpose of this study was to clarify the prognostic significance of triple-negative breast cancer (TNBC) with a tumor size ≤ 1 cm.

MATERIALS AND METHODS

Patients with primary operable breast cancer with a tumor size ≤ 1 cm were enrolled at Changhua Christian Hospital and National Cheng-Kung University Hospital. Tumors negative for ER, PR, and HER-2 were classified as TNBCs and compared with tumors with any receptor positivity (non-TNBC) for disease-free survival (DFS) and cancer-specific survival (CSS).

RESULTS

From 1995 to 2006, a total of 377 patients with tumor size ≤ 1 cm were enrolled. Compared with non-TNBC patients, TNBC patients with a tumor size ≤ 1 cm as a whole or in a lymph node-positive subgroup were not associated with a poorer 5-year DFS and CSS. In lymph node-negative patients (pT1a-bN0M0), TNBC was associated with a poorer 5-year CSS but not DFS. Compared with the hormone receptor-positive, HER-2-negative subgroup, TNBC was associated with poorer DFS and CSS. In the multivariate Cox regression hazard analysis, lymph node invasion was the most important cause of disease recurrence and cancer-specific death.

CONCLUSION

TNBC is very likely an independent risk factor in small (≤1 cm) node-negative invasive breast cancer. With tumors 1 cm and smaller, lymph node invasion was the single most important prognostic factor.

Ionophore-catalyzed cation transport between phospholipid inverted micelles manifest in DNMR

Studies of hyperfine shifts of lipid 31P resonances due to hydrated phospholipid inverted micelles in benzene are presented. Systems with distinct resonances from micelles containing no paramagnetic ions, and from micelles containing a single praseodymium(III) or a single europium(III) ion (and three nitrate counterions) have been generated. The addition of an ionophoric antibiotic from Streptomyces lasaliensis, lasalocid-A (X537A). causes both resonances to broaden and. with further additions, coalesce and eventually resharpen as a single line. Dilution of only the ionophore reverses these spectral changes. This is interpreted as a manifestation of dynamic NMR (DNMR. exchange broadening): i.e., that the ionophore catalyzes the equilibrium exchange of metal ions from micelle to micelle to the point where it becomes fast on the NMR time scale. This exchange is inhibited by protons or other competitive metal ions. We have simulated the spectra with a total lineshape analysis program and have thus extracted the average preexchange lifetimes for various concentrations of the antibiotic. We find a reasonably good first-order dependence on lasalocid-A concentration in each of several different experiments. This is in contrast to the higher order concentration dependences often observed by others using different techniques employing bilayer membranes. We favor a diffusional carrier mechanism involving surface aggregates of lasalocid-A for our process. This leads to the implication that a higher order concentration dependence found for a bilayer system arises from a different mechanism. The ionophore valinomycin does not catalyze rapid exchange in our system.

Clinical features, vascular risk factors, and prognosis for transient global amnesia in Chinese patients

BACKGROUND

Transient global amnesia (TGA) is an intriguing clinical syndrome that has not been studied in a series of Chinese patients.

METHODS

From 1989 to 1995, we observed 28 consecutive patients with TGA. Their clinical characteristics, risk factors, and outcome were retrospectively reviewed and analyzed.

RESULTS

There were 13 men and 15 women with a mean age of 62 years (range, 39 to 76). The duration of amnesic attack ranged from 20 minutes to 24 hours (mean, 8 hours), with the majority (76%) of attacks lasting for 2 to 12 hours. In 9 (32%) of the 28 patients, the TGA was triggered by a potential precipitating factor including bathing, emotional stress, and headache. The most prominent symptom exhibited by patients during an attack was repetitive questioning, which occurred in 21 (75%) of the 28 patients. No focal neurological abnormality was noted during or after the attack. Electroencephalograms were obtained in 26 patients after experiencing TGA, which showed nonspecific findings in 6 patients and were normal in 20. In 21 patients who had cranial computed tomography scans, cortical atrophy was found in 5 (24%), focal infarction in 4 (19%), and the results were negative in 12 (57%). Hypertension was the predominant vascular risk factor (11 cases, 39%), then hyperlipidemia (7 cases, 25%), and smoking (3 cases, 11%). No vascular risk factor was found in 13 patients (46%). Recurrent TGA was found in 5 patients (18%), and stroke in 2 (7%).

CONCLUSION

Our study largely confirms the demographic pattern, clinical characteristics, and prognosis of TGA patients reported from the western countries. Although the cause is uncertain, TGA is a relatively benign entity.

Interleukin-1 alpha polymorphism has influence on late-onset sporadic Parkinson's disease in Taiwan

Inflammatory events may contribute to the pathogenesis of Parkinson's disease (PD) and interleukin 1 (IL-1) may exert both neurotoxic and neuroprotective effects. We conducted a case-control study in a cohort of 493 PD cases and 388 ethnically matched controls to investigate the association of IL-1alpha C-889T and IL-1beta C-511T polymorphisms with the risk of PD. No significant difference in the genotype distribution of the analyzed polymorphisms was found between PD and controls. However, after stratification by age, individuals over 70 years of age carrying IL-1alpha-889 C/T genotype demonstrated a significant decrease in risk of developing PD (OR = 0.44; 95% CI = 0.22-0.88, p = 0.021) and the decrease is strengthened by IL-1beta-511 T-carrying genotype (OR = 0.28; 95% CI = 0.11-0.71, p = 0.008). Our data suggest that IL-1alpha, acting synergistically with IL-1beta, plays role in PD susceptibility among Taiwanese people older than 70 years of age.

The use of a dental implant as an abutment in three unit implant-tooth supported fixed partial denture: a case report and 32 month follow-up

The combined use of dental implants and teeth as abutments in fixed partial dentures may offer advantages to both patients and practitioners in certain clinical situations. An implant-tooth retained prosthesis may reduce surgical intervention and cost to the patient. It may also mean that anatomical restrictions to the provision of an implant-retained fixed prosthesis may be overcome. In this case report, the steps in provision of a three unit implant-to-tooth fixed partial denture are described and the treatment planning and prognosis of a restoration of this type are discussed.

Clinical characteristics of multiple sclerosis in Taiwan: a cross-sectional study

This study reviewed the clinical characteristics of multiple sclerosis (MS) in Taiwanese patients from 1993 to 2001. Of the 75 MS patients with a mean age of onset of 35.6 +/- 12.6 years, the female-to-male ratio was 4.4 (61/14). In 42 (56%) optico-spinal MS (OS-MS) patients, the age of onset (37.6 +/- 11.1 years) tended to be older than conventional MS (C-MS) patients (33.1 +/- 14.1 years, P = 0.08). In 60 cerebrospinal fluid (CSF) specimens, raised IgG index (>0.7) and oligoclonal bands were noted in 26 (43.3%) and two (3.3%) cases, respectively. The frequency of raised IgG index was lower in OS-MS (31.3%) than in C-MS (57.1%, P = 0.07). The CSF total protein concentrations were significantly higher in OS-MS (64.5 mg/dL) than in C-MS (46.6 mg/dL, P = 0.047). The mean annual relapse rate was 54.1%, and was significantly higher within the first year (59.7%, P < 0.001). The mean annual relapse rate in OS-MS (62.7%) was significantly higher than in C-MS (41.2%, P=0.01). The differences in the annual relapse rate and total protein concentration in CSF between OS-MS and C-MS suggest probably two distinct immunopathogenesis. The higher first year relapse rate of MS patients in Taiwan may address the importance of early intervention with immunomodulatory therapy.

Genistein-induced neuronal differentiation is associated with activation of extracellular signal-regulated kinases and upregulation of p21 and N-cadherin

Neuronal differentiation in the mammalian CNS is driven by multiple events. When treated with retinoic acid (RA), hNTera-2 (NT-2) cells undergo postmitotic neuronal differentiation. Here, we show that a prolonged exposure of NT-2 cells with non-cytotoxic doses of genistein, a protein tyrosine kinase (PTK) inhibitor, induced differentiation of NT-2 cells. Additionally, genistein enhanced RA-induced neuronal differentiation by increasing the activation of extracellular signal-related kinase 1/2 (ERK1/2) via phosphorylation at Thr183 and Tyr185 in 3-7 days. Meanwhile, genistein also upregulated N-cadherin and p21 (a Cdk inhibitor), but downregulated proliferating cell nuclear antigen protein (PCNA). MEK1/2 inhibitors, such as PD98059 and U0126, reduced RA-induced ERK1/2 activity, but could not block the genistein effects. Our observations indicate that genistein-induced neuronal differentiation is not dependent of the MEK-ERK signaling cascade. Instead, genistein-upregulated ERK activation is likely due to this chemical's direct effect on chromosome and gene transcription, rather than its inhibition on tyrosine kinases. Failure of inhibition of ERK1/2 activation by the MEK1/2 inhibitors PD98059 and U0126 suggests presence of an unknown activator for ERK1/2 in neuronal cells.

Choice of endogenous control for gene expression in nonsmall cell lung cancer

This study attempts to identify a suitable endogenous control gene for real-time RT-PCR in nonsmall cell lung cancer (NSCLC) tissues. Expression of seven common endogenous control genes (glyceraldehyde-3-phosphate dehydrogenase (GAPDH), v-abl Abelson murine leukaemia viral oncogene homologue 1, beta-2-microglobulin, hypoxanthin phosphoribosyltransferase 1 (HPRT1), phosphoglycerate kinase 1, peptidylprolyl isomerase A, and ribosomal protein, large, P0) in 18 heterogenous NSCLC tumour specimens, 10 normal lung tissues and six NSCLC cell lines were analysed by quantitative RT-PCR. The variances and correlation coefficients of cycle threshold (Ct) value of each control gene in three tissue groups and subgroups were compared. The difference and correlation coefficients between the Ct value for each control gene and the mean Ct value of the remaining control genes were calculated. The GAPDH gene transcript showed the least variance and linear regression analysis demonstrated that GAPDH and HPRT had the strongest correlation in pooled tumour and normal lung tissues. Furthermore, GAPDH expression value showed stringent correlation and had the lowest difference with the mean expression value of the remaining endogenous control genes. Among the seven common endogenous control genes, glyceraldehyde-3-phosphate dehydrogenase is the most suitable for quantitative RT-PCR reaction in nonsmall cell lung cancer tissue samples.

Analysis of polyglutamine-coding repeats in the TATA-binding protein in different neurodegenerative diseases

Trinucleotide repeat (TNR) expansion in the gene for TATA binding protein (TBP) has recently been described as causal for spinocerebellar ataxia type 17. The normal number of repeats has been considered to be 42 or less. An intermediate range with reduced penetrance has been assumed to be 43-47 CAA/CAG repeats. We examined this gene in 30 patients with autosomal-dominant cerebellar ataxia (ADCA), 35 patients with sporadic ataxia, 11 patients with Huntington's disease (HD), 351 patients with idiopathic Parkinson's disease (PD), 105 patients with Alzheimer's disease (AD), and 291 controls with no history of neurodegenerative disease. Three patients (one with sporadic PD and two with AD) carrying more than 42 TNRs in the TBP gene were identified. This reveals that the phenotype associated with CAG/CAA expansion in the TBP gene may be heterogeneous.

DNA haplotype analysis of CAG repeat in Taiwanese Huntington's disease patients

We studied the expanded CAG repeat and adjacent CCG repeat in 53 Huntington's disease (HD) patients and 172 unrelated normal subjects matched to the patients for ethnic origin. The range of the CAG repeat varied from 38 to 109 in the HD patients and from 10 to 29 in the control group. A significant negative correlation was found between the age at onset and the CAG expansion, with no significant influence of the adjacent CCG repeat on the age at onset by multiple regression analysis. Allelic association using CCG repeat and 2 flanking dinucleotide repeat markers within 150 kb of the HD gene revealed linkage disequilibrium for 2 of 3 markers. Haplotype analysis of 24 HD families using these markers identified 3 major haplotypes underlying 87.5% of HD chromosomes. The data suggested frequent haplotypes in the Taiwanese population on which one or more mutational events leading to the disease occurred.

A case of Collet-Sicard syndrome associated with traumatic atlas fractures and congenital basilar invagination

An 18 year old man with congenital basilar invagination developed multiple lower cranial nerve (CN) palsies including CN IX to XII after a traffic accident. Computed tomography of his skull base revealed a two part atlas Jefferson fracture. Normally, lower cranial nerves (CN IX-XII) pass through a space between the styloid process and the atlas transverse process. Atlas burst fractures rarely cause neurological deficits because of a greater transverse and sagittal diameter of the spinal canal at the atlas, and a tendency of the lateral masses to slide away from the cord after injury. However, when associated with a rare condition-congenital basilar invagination-atlas fractures can compromise the space and make CN IX-XII more vulnerable to compression injury. This report discusses the correlation between the anatomical lesions and clinical features of this patient.

Expression of WW domain-containing oxidoreductase WOX1 in the developing murine nervous system

WW domain-containing oxidoreductase WOX1, also known as WWOX or FOR, is a proapoptotic protein and a putative tumor suppressor. Hyaluronidases such as PH-20, Hyal-1 and Hyal-2 induce the expression of WOX1, and hyaluronidases and hyaluronan are involved in the embryonic development. In the present study, we document the expression of WOX1 in the developing murine nervous system. Immunohistochemical analysis revealed that WOX1 was differentially expressed in early dividing cells from all three germ layers from embryonic to perinatal stages. In murine fetuses, WOX1 was present prevalently in the brainstem, spinal cord and peripheral nerve bundles, but its expression decreased after birth. In parallel, the expression of WOX1, as determined by Western blotting, was significantly reduced in the brain stem and spinal cord of adult mice. Notably, high levels of WOX1 immunoreactivity was observed in the neural crest-derived structures such as cranial and spinal ganglia and cranial mesenchyme during the late fetal stage. In the adult brain, WOX1 is abundant in the epithelial cells of the choroids plexus and ependymal cells, while a low to moderate level of WOX1 is observed within white matter tracts, such as axonal profiles of the corpus callosum, striatum, optic tract, and cerebral peduncle. WOX1 is shown to mediate apoptosis synergistically with p53 in vitro. Nonetheless, the expression profiles of WOX1 were found to be similar in both p53 wild type and knockout mice, suggesting that WOX1 expression is not controlled by p53-mediated gene transcription. Taken together, in this study we have shown the expression and distribution of WOX1 in developing and adult murine nervous system. The potential role of WOX1 in the neuronal differentiation is discussed.

The retina as a novel in vivo model for studying the role of molecules of the Bcl-2 family in relation to MPTP neurotoxicity

To determine the roles of different members of the family of B cell lymphoma protooncogene (Bcl-2) in relation to neurotoxin-induced neuronal degeneration, the pattern of the expression of a number of molecules of the Bcl-2 family was studied immunocytochemically in the retinas of C57BL/6J mice after intraperitoneal (IP) injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Three days to 12 weeks after MPTP treatment, a detectable reduction of tyrosine hydroxylase immunoreactivity in the amacrine cells was observed, with an increase of Bcl-2 expression in the Müller glial cells, and a de novo expression of Bad and Bax in the retinal ganglion cells, optic nerve fibers and plexiform layers. In contrast, a slight decrease of Bcl-x(L) immunoreactivity in the retinal ganglion cells was observed, whereas Bcl-x(S/L) immunoreactivity was increased slightly in the retinas of MPTP-treated mice compared with that of the controls. In animals that received MPTP injection, an increase in immunostaining of GFAP, glutamine synthetase, and Mac-1 (CD11b) in astrocytes, Müller cells, and microglia was invariably observed, indicating an activation or dysfunction of retinal glial cells. These findings are consistent with the current view that glial dysfunction is important in mediating the cytotoxic effect of a variety of neurotoxic molecules, including MPTP, and that different members of Bcl-2 family may have different roles as far as neuronal degeneration or neuroprotection is concerned.

Immediate restoration of an immediate single-tooth implant

Traditional implant protocol specifies an unloaded healing period prior to restoration. Shorter healing times may be appropriate in some circumstances, and examples of early loading have been reported in the dental literature. This case report involves immediate implant placement at the time of tooth extraction, combined with construction of a restoration, inserted directly after implant surgery. The clinical procedures are described, and the specific indications which may permit this approach are presented.

Effects of volatile fatty acids on a thermophilic anaerobic hydrogen fermentation process degrading peptone

Hydrogen fermentation using glucose as a single substrate caused abrupt pH drops and the gradual losses of hydrogen producers, which in turn led to system failure. In this study the use of a proteinaceous substrate, peptone, avoided the abrupt pH drops in the reactive system and allowed for further exploration of volatile fatty acids (VFAs) and pH effects on the hydrogen fermentation process. Our results showed that: (1) during the hydrogen fermentation tests, the abrupt pH drops were avoided thus system stability increased due to the production of ammonia from the peptone fermented, (2) pH control was not necessary and the addition of acetate to the process had little effect on the hydrogen fermentation process, (3) at the extreme pHs the addition of acetate either lengthened the lag phase (pH < or = 6) or slowed the hydrogen production rate (pH > or = 8), and both situations were not desired, and (4) high VFA content in the system sped up the consumption of hydrogen gas. Results of this study suggested that the hydrogen fermentation using the protein-containing substances as substrate was beneficial in maintaining the system pH. As long as the pH was maintained around 6-8, system inhibition due to VFAs accumulation was minimized. Thus, the optimal operation of a hydrogen fermentation process would be achievable via the control of substrate composition at a certain carbohydrate-to-protein ratio.

Memory self-appraisal and depressive symptoms in people at genetic risk for Alzheimer's disease

OBJECTIVES

A previous study found that subjective memory loss in middle-aged and older persons is associated with the major genetic risk for Alzheimer's disease, the apolipoprotein E-4 (APOE-4) allele. No previous study has focused on subjective memory complaints and depressive symptoms in the same subject population at genetic risk for Alzheimer's disease.

METHOD

Sixty-six persons (mean age = 64 years, range = 43 to 82 years) without major depression or dementia but with mild age-related memory complaints were rated for severity of depressive symptoms, using the Hamilton Depression Rating Scale, and assessed for the presence of the APOE-4 allele. Severity of subjective memory loss was assessed using the Memory Functioning Questionnaire, which measures four memory domains: frequency of forgetting, seriousness of forgetting, retrospective functioning, and mnemonics usage.

RESULTS

Depressive symptoms were significantly associated with subjective memory loss in subjects without the APOE-4 allele, for retrospective functioning (perceived change in memory) and mnemonics usage, but not in APOE-4 carriers. The same significant associations were found when the analysis was limited to the 44 subjects in the mid-age range (55-74 years), wherein APOE-4 confers its greatest effects on risk for Alzheimer's disease.

CONCLUSION

These results confirm that mild depressive symptoms are related to subjective memory loss, but for some forms of memory complaint, the relationship holds true only for people without the major known genetic risk for Alzheimer's disease.

Phosphorylation of the 24p3 protein secreted from mouse uterus in vitro and in vivo

The 24p3 protein is a 25 KDa glycoprotein, having been purified from mouse uterine fluid. Thr54, Ser88, and Thr128/Ser129 on the protein molecule were predicted to be the phosphorylation site of casein kinase II, protein kinase C, and cAMP-dependent protein kinase, respectively. Incorporation of phosphate to this protein from [gamma-32P]-ATP was tested in the solution suitable for the three kinases. Neither casein kinase II nor cAMP-dependent protein kinase reacted to the 24p3 protein; however, protein kinase C demonstrated phosphorylation to this protein. This phosphorylation may be competing with a polypeptide segment: Arg79-Tyr-Trp-Ilu-Arg-Thr-Phe-Val-Pro-Ser88-Ser-Arg-Ala-Gly-Gln-Phe-Thr-Leu-Gly97 in the 24p3 protein molecule. To support this theory, Ser88 is a phosphorylation site of protein kinase C on 24p3 protein. The enzyme kinetic parameter, based on the Michaelis-Menten equation, determined Km to be 2.96 microM in the phosphorylation of 24p3 protein by the kinase. Both of the phosphorylated and dephosphorylated form of 24p3 protein can enhance the cAMP-dependent protein kinase activity in vitro. In addition, this experiment will show for the first time that serine-phosphorylated 24p3 protein exists in mouse uterine tissue.

Cloning and characterization of hMAP126, a new member of mitotic spindle-associated proteins

One novel gene product, hMAP126, was demonstrated to interact with p29 in the yeast two-hybrid assay. The full-length cDNA of hMAP126 has been obtained and encodes a protein of 1120 amino acids. Multiple tissue Northern blot analysis showed that hMAP126 was abundantly expressed in the testis. Polyclonal antiserum against hMAP126 was raised and affinity-purification of anti-hMAP126 antibodies was performed. The subcellular distribution of hMAP126 was localized to the mitotic spindle. Furthermore, hMAP126 was identified to be post-translationally modified and phosphorylated by p34(cdc2) kinase in vitro. Taken together, we have isolated a novel protein, hMAP126, which may be involved in the functional and dynamic regulation of mitotic spindles.

Proteomic analysis of proteins in PC12 cells before and after treatment with nerve growth factor: increased levels of a 43-kDa chromogranin B-derived fragment during neuronal differentiation

Proteomic analysis is an important approach to characterizing the proteome and studying protein function in the post-genomic era. It is also a powerful screening method for detecting unexpected alterations in protein expression that may be missed by conventional biochemical techniques. The aim of this study was to perform a preliminary proteomic analysis of PC12 cells in order to investigate the effect of nerve growth factor (NGF) on protein expression in PC12 cells during neurite outgrowth. PC12 cell proteins were separated by two-dimensional electrophoresis (2DE) and visualized by silver staining, then certain proteins were identified by N-terminal amino acid microsequencing and a homology search of a protein sequence database. Over 400 proteins were detected, 10% of which showed a significant (greater than 30%) increase or decrease in expression during NGF-induced neuronal differentiation. Seven proteins in the 2DE map were identified; the levels of five of these were unaffected by NGF treatment, whereas the levels of the other two, beta-tubulin and a novel 43-kDa chromogranin B-derived fragment, were significantly increased by more than 30 and 200%, respectively. Our results suggest that chromogranin B processing is enhanced in PC12 cells during NGF-induced neuronal differentiation. In addition, since this increase in the levels of the chromogranin B-derived fragment was specifically blocked by PD98059, we suggest that the increased processing can be ascribed to activation of the MAP kinase pathway, and that the 43-kDa chromogranin B-derived fragment can serve as a new marker of neuronal differentiation for proteomic studies.

Optimization of a thermostable lipase from Bacillus stearothermophilus P1: overexpression, purification, and characterization

An expression library was generated from a partial NcoI and HindIII digest of genomic DNA from the thermophilic bacterium, Bacillus stearothermophilus P1. The DNA fragments were cloned into the expression vector pQE-60 and transformed into Escherichia coli M15[EP4]. Sequence analysis of a lipase gene showed an open reading frame of 1254 nucleotides coding a 29-amino-acid signal sequence and a mature sequence of 388 amino acids. The expressed lipase was isolated and purified to homogeneity in a single chromatographic step. The molecular mass of the lipase was determined to be approximately 43 kDa by SDS-PAGE and mass spectrometry. The purified lipase had an optimum pH of 8.5 and showed maximal activity at 55 degrees C. It was highly stable in the temperature range of 30-65 degrees C. The highest activity was found with p-nitrophenyl ester-caprate as the synthetic substrate and tricaprylin as the triacylglycerol. Its activity was strongly inhibited by 10 mM phenylmethanesulfonyl fluoride and 1-hexadecanesulfonyl chloride, indicating that it contains a serine residue which plays a key role in the catalytic mechanism. In addition, it was stable for 1 h at 37 degrees C in 0.1% Chaps and Triton X-100.

Development of an MFG-based retroviral vector system for secretion of high levels of functionally active human BMP4

We sought to develop a retroviral vector system that would produce secretion of high levels of bone morphogenetic protein (BMP)-4 by optimizing the expression construct and developing an improved retroviral vector. Replacement of the propeptide domain of BMP4 with that of BMP2 increased the secretion level of mature BMP4 protein in transduced cells. The intact BMP2 pro-peptide sequence was essential, as deletion of a small part of the propeptide sequence of BMP2 from the BMP2/4 hybrid construct diminished BMP4 expression and secretion. Addition of a hemaglutinin tag to the carboxy terminus of BMP4 abolished the bioactivity of secreted BMP4. Transduction of rat marrow stromal cells (and fibroblasts) with an MFG-based retroviral vector pseudotyped with VSV-G envelope containing this BMP2/4 hybrid expression construct led to secretion of very high levels of mature BMP4 in conditioned medium (up to 1 microg/10(6) cells/24 hours). The secreted BMP4 was biologically active, as it induced alkaline phosphatase expression in C2C12 cells. The transduced rat marrow stromal cells expressing mature BMP4 induced de novo ectopic bone formation in syngenic immune-competent rats. We have developed an MFG-based retroviral vector system that causes secretion of high levels of functionally active human BMP4 protein.

The early stages of filamentous phage phiLf infection require the host transcription factor, Clp

Xanthomonas campestris pv. campestris produces great amounts of an exopolysaccharide (EPS), xanthan gum. Eight eps loci involved in biosynthesis of the EPS were previously located in the chromosome map of strain Xc17. In this study, the eps8 region was cloned, sequenced and found to contain a crp homologue whose deduced amino acid sequence possesses similarity to that of the cyclic AMP receptor protein of bacteria, with the highest identity (97%) being shared with the X. campestris pv. campestris B-1459 clp gene previously shown to be involved in pathogenicity and regulation of the production of xanthan, extracellular enzymes, and pigment (de Crecy-Lagard V., Glaser P., Lejeune P., Sismeiro O., Barber C.E., Daniels M.J., and Danchin A., J. Bacteriol. 172:5877-5883, 1990). Based on sequence identity, pleiotropic effects of the mutation, the ability to complement an Escherichia coli cya crp mutant, and Southern hybridization detecting a single copy in the chromosome, we propose this eps8 gene to be the Xc17 clp. In addition to the previously reported properties, a clp mutant (AU56E) cannot be plaqued with filamentous phage phiLf, although it retains the capability to support phiLf DNA replication and release authentic phage particles upon electroporation of the RF DNA. Infective center assays demonstrated that the frequency of infection is 460- to 7,500-fold lower in AU56E compared to that in the wild-type Xc17. Electron microscopy, which showed no surface appendages other than the monotrichous flagellum, confirmed that AU56E drastically diminishes in the efficiency of phage adsorption. These results suggest Clp to be regulating the biosynthesis of the primary receptor, most likely a type IV pilus. Upstream to clp is a homologue of the E. coli speD gene required for spermidine synthesis. Mutation of the clp flanking regions and transcriptional analyses suggest clp to be monocistronic and the only gene contained at the eps8 locus.

Structural modeling and characterization of a thermostable lipase from Bacillus stearothermophilus P1

The moderate thermophilic bacterium Bacillus stearothermophilus P1 expresses a thermostable lipase that was active and stable at the high temperature. Based on secondary structure predictions and secondary structure-driven multiple sequence alignment with the homologous lipases of known three-dimensional (3-D) structure, we constructed the 3-D structure model of this enzyme and the model reveals the topological organization of the fold, corroborating our predictions. We hypothesized for this enzyme the alpha/beta-hydrolase fold typical of several lipases and identified Ser-113, Asp-317, and His-358 as the putative members of the catalytic triad that are located close to each other at hydrogen bond distances. In addition, the strongly inhibited enzyme by 10 mM PMSF and 1-hexadecanesulfonyl chloride was indicated that it contains a serine residue which plays a key role in the catalytic mechanism. It was also confirmed by site-directed mutagenesis that mutated Ser-113, Asp-317, and His-358 to Ala and the activity of the mutant enzyme was drastically reduced.

The catalytic mechanism of 1-aminocyclopropane-1-carboxylic acid oxidase

It has been proposed that 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase catalyzes the oxidation of ACC to ethylene via N-hydroxyl-ACC as an intermediate. However, due to its chemical instability the putative intermediate has never been isolated. Here, we have shown that a purified recombinant ACC oxidase can utilize alpha-aminoisobutyric acid (AIB), an analog of ACC, as an alternative substrate, converting AIB into CO2, acetone, and ammonia. We chemically synthesized the putative intermediate compound, N-hydroxyl-AIB (HAIB), and tested whether it serves as an intermediate in the oxidation of AIB. When [1-(14)C]AIB was incubated with ACC oxidase in the presence of excess unlabeled HAIB as a trap, no labeled HAIB was detected. By comparing the acetone production rates employing HAIB and AIB as substrates, the conversion of HAIB to acetone was found to be much slower than that of using AIB as substrate. Based on these observations, we conclude that ACC oxidase does not catalyze via the N-hydroxylation of its amino acid substrate. ACC oxidase also catalyzes the oxidation of other amino acids, with preference for the D-enantiomers, indicating a stereoselectivity of the enzyme.