[Determination of phthalic diesters in water by solid phase microextraction-capillary gas chromatography]

The solid phase microextraction (SPME) has the advantages of high efficiency, high sensitivity, simple operation and solvent free operation for analyzing environmental samples. An optical fiber coated with mixed stationary phase of polysiloxane and polymeric fullerene (in ratio of 4:1) was used to extract 5 phthalic diesters by HS-SPME-GC. The operating conditions of SPME such as the extraction temperature, ionic strength of solution, adsorption time and desorption time have been studied. It was compared with commercial polymer coating PDMS fiber through headspace SPME combined with GC. The results indicated that OV-1/PSO-C60 was better than PDMS in extracting high boiling point and semi-volatile phthalic diesters. For phthalic diesters, the detection limits were in the range of 0.331 ng/L-12.5 micrograms/L, and relative standard deviations were below 12% except for dinonyl phthalate.

An assessment of air toxics in Minnesota

We used monitoring and modeling to assess the concentrations of air toxics in the state of Minnesota. Model-predicted concentrations for 148 hazardous air pollutants were from the U.S. Environmental Protection Agency Cumulative Exposure Project (1990 data). Monitoring data consisted of samples of volatile organic compounds, carbonyls, and particulate matter [Less than and equal to] 10 microm in aerodynamic diameter collected at 25 sites throughout the state for varying periods of time (up to 8 years; 1991-1998). Ten pollutants exceeded health benchmark values at one or more sites by modeling, monitoring, or both (including acrolein, arsenic, benzene, 1,3-butadiene, carbon tetrachloride, chromium, chloroform, ethylene dibromide, formaldehyde, and nickel). Polycyclic organic matter also exceeded the benzo[a]pyrene health benchmark value assumed to represent this class of pollutants. The highest modeled and monitored concentrations of most pollutants were near the center of the Minneapolis-St. Paul metropolitan area; however, many smaller cities throughout the state also had elevated concentrations. Where direct comparisons were possible, monitored values often tended to exceed model estimates. Upper-bound excess lifetime inhalation cancer risks were estimated to range from 2.7 [times] 10(-5) to 140. 9 [times] 10(-5) (modeling) and 4.7 [times] 10(-5) to 11.0 [times] 10(-5) (using a smaller set of monitored carcinogens). Screening noncancer hazard indices summed over all end points ranged from 0.2 to 58.1 (modeling) and 0.6 to 2.0 (with a smaller set of monitored pollutants). For common sets of pollutants, the concentrations, cancer risks, and noncancer hazard indices were comparable between model-based estimates and monitored values. The inhalation cancer risk was apportioned to mobile sources (54%), area sources (22%), point sources (12%), and background (12%). This study provides evidence that air toxics are a public health concern in Minnesota.

The suppressive effect of TGF-beta on IL-12-mediated immune modulation specific to a peptide Ac1-11 of myelin basic protein (MBP): a mechanism involved in inhibition of both IL-12 receptor beta1 and beta2

Transforming growth factor (TGF)-beta exerts a counter-regulatory effect on interleukin (IL)-12-mediated immune modulation. The underlying mechanism is not fully understood. Here we demonstrate that the expression of IL-12Rbeta1 and IL-12Rbeta2 in MBP peptide Ac1-11-primed splenocytes is upregulated upon antigen stimulation. TGF-beta induces an unresponsiveness of these primed splenocytes to IL-12 signaling through a mechanism involved in inhibition of both IL-12Rbeta1 and beta2. The modulation of IL-12Rbeta1 and beta2 expression by Ac1-11 stimulation and TGF-beta is mainly involved in CD4+ population. These data indicate that both IL-12Rbeta1 and IL-12Rbeta2 expression are crucial during T cell activation. TGF-beta-induced inhibition of IL-12R expression will reduce cellular immune responses during IL-12-mediated autoimmune disease.

BRCA1 mutations in Taiwanese with epithelial ovarian carcinoma and sporadic primary serous peritoneal carcinoma

BACKGROUND

Germline BRCA1 mutations of sporadic ovarian cancers are presumed to be rare events, except among specific populations. To date, the status of germline BRCA1 mutations in Taiwanese with primary epithelial ovarian carcinoma (PEOC) is still unknown. In this study, we tried to answer part of this question.

METHODS

Sixty-four patients documented with PEOC, four patients with family history of breast and/or ovary cancer syndrome and five patients with sporadic primary serous peritoneal carcinoma (PSPC) were enrolled in this retrospective study from January 1994 through June 1999. At the same time, 50 normal healthy Taiwanese without family history were enrolled in this study. Germline DNA from these patients was screened for mutations in the BRCA1 gene using polymerase chain reaction-based single-stranded conformation polymorphism analysis (PCR-SSCP). Shifting DNA bands were sequenced.

RESULTS

One of the 64 patients with PEOC (1.6%) exhibited germline BRCA1 heterozygous mutation which was exon11 single-base substitution at nucleotide1047 (CAG to TAG). One of the five patients with PSPC (20%) exhibited an exon11 single-base substitution at nucleotide 914 (TCT to TCC) with resultant silent mutation. One of the normal healthy Taiwanese (2%) was found to have an exon 2 single-base substitution at nucleotide 152 (A-->C) which was also a silent mutation. No mutations of BRCA1 were detected in four patients with a family history of breast and/or ovarian cancer.

CONCLUSIONS

Based on this study, it was very difficult to obtain precise data to prove the value of applying genetic testing of BRCA1 mutations in Taiwanese patients with sporadic epithelial ovarian cancers or sporadic PSPC and even with a family history of breast and/or ovarian cancer because of its rare event and because of the too small number of cases available in this study.

DNA vaccines: a key for inducing long-term cellular immunity

Over the past few years, major advances in several areas of immunology have provided a foundation for the rational design of vaccines against diseases requiring cellular immunity. Among these advances are the cellular mechanisms by which DNA vaccines can sustain long-term humoral and cellular immunity.

Endoscopic treatment of bleeding gastric varices by N-butyl-2-cyanoacrylate (Histoacryl) injection: long-term efficacy and safety

BACKGROUND

The long-term efficacy and safety of the endoscopic injection of N-butyl-2-cyanoacrylate (Histoacryl) were evaluated to define its role as the initial treatment for bleeding gastric varices.

METHODS

Ninety patients with bleeding gastric varices underwent endoscopic injections of Histoacryl for hemostasis within a 6-year period. Histoacryl was injected intravariceally as a 1:1 mixture with Lipiodol. Among the 90 patients, 5 had active bleeding and 85 had recent bleeding. Most of the varices were large (F2 or F3, 85 cases). The most common locations were the fundus and the posterior wall of the proximal body (94.4%). After Histoacryl injection, patients were followed endoscopically with retreatment as necessary.

RESULTS

The rate of hemostasis at 1 week was 94.4%. Recurrent bleeding occurred in 23.3% of the patients from 3 days to 16 months after the initial injection. Recurrent bleeding was stopped with reinjections of Histoacryl in 16.7% of the patients. The rate of definitive hemostasis was 93.3% (84 of 90). The treatment failure-related mortality rate was 2.2% (2 of 90). To date, 35 patients have died, mostly as a result of malignancy or liver failure, and 55 are still alive. The determining factor for long-term survival was the underlying disease leading to portal hypertension. There were few long-term complications except for Histoacryl cast extrusion-related mucosal defects.

CONCLUSIONS

Endoscopic injection of Histoacryl is highly effective for the treatment of bleeding gastric varices, with rare complications both acutely and long term. This treatment modality is appropriate as the first choice for bleeding gastric varices.

The role of antigen and IL-12 in sustaining Th1 memory cells in vivo: IL-12 is required to maintain memory/effector Th1 cells sufficient to mediate protection to an infectious parasite challenge

IL-12 plays a central role in both the induction and magnitude of a primary Th1 response. A critical question in designing vaccines for diseases requiring Th1 immunity such as Mycobacterium tuberculosis and Leishmania major is the requirements to sustain memory/effector Th1 cells in vivo. This report examines the role of IL-12 and antigen in sustaining Th1 responses sufficient for protective immunity to L. major after vaccination with LACK protein (LP) plus rIL-12 and LACK DNA. It shows that, after initial vaccination with LP plus rIL-12, supplemental boosting with either LP or rIL-12 is necessary but not sufficient to fully sustain long-term Th1 immunity. Moreover, endogenous IL-12 is also shown to be required for the induction, maintenance, and effector phase of the Th1 response after LACK DNA vaccination. Finally, IL-12 is required to sustain Th1 cells and control parasite growth in susceptible and resistant strains of mice during primary and secondary infection. Taken together, these data show that IL-12 is essential to sustain a sufficient number of memory/effector Th1 cells generated in vivo to mediate long-term protection to an intracellular pathogen.

Requirements for the maintenance of Th1 immunity in vivo following DNA vaccination: a potential immunoregulatory role for CD8+ T cells

Protective immunity against Leishmania major generated by DNA encoding the LACK (Leishmania homologue of receptor for activated C kinase) Ag has been shown to be more durable than vaccination with LACK protein plus IL-12. One mechanism to account for this may be the selective ability of DNA vaccination to induce CD8+ IFN-gamma-producing T cells. In this regard, we previously reported that depletion of CD8+ T cells in LACK DNA-vaccinated mice abrogated protection when infectious challenge was done 2 wk postvaccination. In this study, we extend these findings to study the mechanism by which CD8+ T cells induced by LACK DNA vaccination mediate both short- and long-term protective immunity against L. major. Mice vaccinated with LACK DNA and depleted of CD8+ T cells at the time of vaccination or infection were unable to control infection when challenge was done 2 or 12 wk postvaccination. Remarkably, it was noted that depletion of CD8+ T cells in LACK DNA-vaccinated mice was associated with a striking decrease in the frequency of LACK-specific CD4+ IFN-gamma-producing T cells both before and after infection. Moreover, data are presented to suggest a mechanism by which CD8+ T cells exert this regulatory role. Taken together, these data provide additional insight into how Th1 cells are generated and sustained in vivo and suggest a potentially novel immunoregulatory role for CD8+ T cells following DNA vaccination.

[Determination of residues of 20 kinds of organochlorinated pesticides in oils, fruits and vegetables by wide-bore capillary gas chromatographic column]

A rapid and high performance gas chromatographic method for the determination of 20 organchlorinated pesticides in oils, fruits and vegetables has been developed. The samples of fruits and vegetables were extracted with petroleum ether-acetone, while those of oils were extracted with acetonitrile-hexane. The extract was purified by Florisil column with ethyl ether-hexane(15:85, V/V) or ethyl ether-petroleum ether(15:85, V/V) as eluent. Chromatographic analysis was performed on wide-bore capillary column with ECD detector. Satisfactory separation and detection of these organchlorinated pesticides are presented with the proposed method. The detection limits of this method were 1.0 ng/g-20.0 ng/g(S/N = 5), the recoveries 83.2%-106.8% and the relative standard deviations 2.0%-9.5%.

Age related testosterone level changes and male andropause syndrome

BACKGROUND

Much like the menopause syndrome occurring among older women, a similar condition has been defined among men. Testosterone production increases rapidly at the onset of puberty, then dwindles quickly after age 50 to become 20 to 50% of the peak level by age 80. Many men older than age 50 have experienced frailty syndrome, which includes decrease of libido, easy fatigue, mood disturbance, accelerated osteoporosis, and decreased muscle strength. We investigated serum total testosterone levels and andropause syndrome in men.

METHODS

Serum total testosterone levels were measured in 53 symptomatic men older than age 50 and in 48 men younger than age 40 for a control group. We also analyzed andropause symptoms among the 53 men older than age 50.

RESULTS

The mean serum total testosterone level in the symptomatic men older than age 50 (mean: 2.68 +/- 0.51 ng/ml, range: 1.21 to 4.13 ng/ml) was significantly lower than that in the control group (mean: 7.01 +/- 0.82 ng/ml, range: 5.53 ng/ml to 8.14 ng/ml). Male frailty syndrome in these men older than 50 included: decreased libido (91%), lack of energy (89%), erection problems (79%), falling asleep after dinner (77%), memory impairment (77%), loss of pubic hair (70%), sad or grumpy mood changes (68%), decrease in endurance (66%), loss of axillary hair (55%), and deterioration in work performance (51%).

CONCLUSION

The serum total testosterone level showed a decline with aging, especially in the men older than age 50. Low serum testosterone levels were also associated with the symptoms of male andropause syndrome.

Relationship between autoantibodies against glutamic acid decarboxylase, thyroglobulin/thyroid microsome and DNA topoisomerase II in the clinical manifestation of patients with type 1 diabetes mellitus in Taiwan

OBJECTIVE

In a preliminary cross-sectional study, we discovered that DNA topoisomerase II autoantibodies (anti-TopII) were detected in 49.2% of 195 Chinese type 1 diabetes mellitus (type 1 DM) patients with a mean age of 14.5 years and a mean duration of disease of 4.6 years. In order to demonstrate the relationship between anti-TopII and other immunological characteristics in Chinese type 1 DM patients, and to evaluate its putative prediction efficacy in Chinese patients, we simultaneously examined the frequency of anti-glutamic acid decarboxylase autoantibodies (anti-GAD), anti-TopII, antithyroglobulin/antimicrosomal autoantibodies (ATA/AMiA) and C-peptide concentrations in our patients in the present study.

DESIGN AND METHODS

The frequency of anti-GAD and C-peptide levels, anti-TopII, and ATA/AMiA were examined in our patients by radioimmunoassay, enzyme-linked immunosorbant assay and hemagglutination respectively. Univariate comparisons were performed using Student's t-test for normal distributed data and Chi-square test for diclomatous data. Multivariate analysis was used for interpreting the independent risk factors which increased the incidence of anti-TopII.

RESULTS AND CONCLUSIONS

The positivities for anti-GAD, anti-TopII, ATA/AMiA and C-peptide were 45.8%, 50.2%, 13.4% and 11.4% respectively. Anti-GAD and anti-TopII frequencies in our patients were similar when we stratified the patients by age, age at onset and duration. These observations imply that anti-GAD and anti-TopII remain persistent in Chinese patients with long-term type 1 DM duration. The most interesting finding is that anti-TopII frequency is more persistent than anti-GAD in our patients, especially when the diabetic duration is longer than 11 years. This indicates that anti-TopII, rather than anti-GAD, might act as a better indicator for monitoring the pathogenesis of Chinese type 1 DM patients especially in patients with a long-standing duration of disease. The late age of onset (>18 years) is a risk factor which increased the incidence of anti-TopII according to multivariate analysis. We further analyzed different manifestations between the youth- and adult-onset type 1 DM and found that adult-onset type 1 DM is characterized by better preservation of residual beta-cell function and higher frequencies of autoantibodies.

Point mutation associated with X-linked dominant Charcot-Marie-Tooth disease impairs the P2 promoter activity of human connexin-32 gene

Many lines of evidence suggest that connexin-32 gap junction is involved in the exchange of information and metabolites in the peripheral nervous system. It has been shown that connexin-32 protein and mRNA are expressed in Schwann cells that function as myelinating cells of the peripheral nervous system. The physiological importance of connexin-32 gap junctions in regulating the normal function of myelinating Schwann cell is indicated by recent findings that X-linked dominant Charcot-Marie-Tooth disease, a hereditary peripheral neuropathy, is associated with the mutations of connexin-32 gene. Recently, we encountered a Taiwanese family affected with X-linked dominant Charcot-Marie-Tooth neuropathy. Therefore, we investigated the possible mutation in the coding and noncoding regions of the connexin-32 gene of affected members of this family. Our results suggest that a G-to-A transition at the position -215 (in relation to the transcription initiation site) of the nerve-specific P2 promoter region is associated with the pathogenesis of X-linked dominant Charcot-Marie-Tooth disease. Further experiments using the promoter assay indicate that G-to-A mutation at the position -215 greatly impairs the transcriptional activity of connexin-32 P2 promoter. These findings propose that a reduced expression of connexin-32 mRNA and protein in the myelin sheath could be responsible for the development of X-linked dominant Charcot-Marie-Tooth neuropathy.

Stat4 is expressed in activated peripheral blood monocytes, dendritic cells, and macrophages at sites of Th1-mediated inflammation

Stat4 is a key transcription factor involved in promoting cell-mediated immunity, whose expression in mature cells has been reported to be restricted to T and NK cells. We demonstrate here, however, that Stat4 expression is not restricted to lymphoid cells. In their basal state, monocytes do not express Stat4. Upon activation, however, IFN-gamma- and LPS-treated monocytes and dendritic cells express high levels of Stat4. Monocyte-expressed Stat4 in humans is phosphorylated in response to IFN-alpha, but not IL-12. In contrast, the Th2 cytokines, IL-4 and IL-10, specifically down-regulate Stat4 expression in activated monocytes, while having little effect on Stat6 expression. Moreover, macrophages in synovial tissue obtained from patients with rheumatoid arthritis express Stat4 in vivo, suggesting a potential role in a prototypical Th1-mediated human disease. IFN-alpha-induced Stat4 activation in human monocytes represents a previously unrecognized signaling pathway at sites of Th1 inflammation.

A proteomic analysis of secreted proteins from xylan-induced Bacillus sp. strain K-1

The expression level of extracellular proteins in an alkaliphilic bacterium, Bacillus sp. strain K-1, grown in a xylan-containing medium, is significantly increased when compared with that grown in the nonxylan culture medium. A proteomic approach has been efficiently applied to separate and characterize these differentially expressed secretory proteins. Eight prominent protein spots were identified and subjected to N-terminal amino acid sequencing. The results show that three spots share considerable similarity with the xylanolytic enzymes and that two spots share considerable similarity with the GltC regulatory protein and 3-dehydroquinate dehydratase, respectively. In addition, the three other proteins show little similarity with the known proteins in the database. In conclusion, our results demonstrate that the proteomic approach is a highly efficient method to rapidly study the differential expression of the secreted proteins by Bacillus sp. strain K-1 grown under xylan-induced condition.

Correlation between Helicobacter pylori infection and gastrointestinal symptoms in pregnancy

Nausea, vomiting, and other dyspeptic symptoms are common in pregnancy. This hospital-based, cross-sectional study was designed to determine the role of Helicobacter pylori infection in gastrointestinal (GI) symptoms during pregnancy. Standardized verbal scales were used to evaluate the frequency and severity of GI symptoms in 54 women whose pregnancies were in the first 16 gestational weeks. H. pylori infection was defined as a positive serum immunoglobulin G result on an immunochromatographic assay. The H. pylori seropositivity rate was higher in the pregnant women (69%) than in the general population (approximately 50%-55%), but seropositivity did not correlate with clinical symptoms. Moreover, no specific patterns of GI symptoms were uncovered in the H. pylori-infected patients. Maternal age, body weight, parity, gestational week, and educational level were not associated with H. pylori infection; neither were the prevalence and severity of GI symptoms.

Cytokine regulation of IL-12 receptor beta2 expression: differential effects on human T and NK cells

The biological activities of IL-12 are mediated through a specific, high-affinity receptor composed of IL-12 receptor(R)beta1 and IL-12Rbeta2 subunits that exist primarily on T and NK cells. Remarkably, the expression of IL-12Rbeta2 on CD4(+) T cells in mouse and humans appears to be differentially regulated by IFN-gamma and IFN-alpha, respectively. Using an antibody specific for the human IL-12Rbeta2 subunit, the effect of IFN-gamma, IFN-alpha, IL-12 and IL-2 on the regulation of IL-12R expression and IL-12 responsiveness of human T and NK cells was assessed. The presence of IFN-alpha or IFN-gamma in cultures enhanced IL-12Rbeta2 expression of CD4(+) and CD8(+) T cells. The enhancing effect of IFN-alpha and IFN-gamma was independent of endogenous IL-12. Furthermore, the clearest effects of IFN-alpha and IFN-gamma on IL-12Rbeta2 expression on T cells were seen by abrograting the inhibition induced by the presence of IL-4 in cultures. In contrast to T cells, IFN-alpha and IFN-gamma had little effect on regulating IL-12Rbeta2 expression on human NK cells. Taken together, these data show that there is differential regulation of IL-12Rbeta2 expression by IFN-alpha and IFN-gamma on human T and NK cells.

Repeat transthoracic endoscopic sympathectomy for palmar and axillary hyperhidrosis

BACKGROUND

Patients undergoing an unsuccessful sympathectomy experience dryness on one hand and excessive sweating on the other. This is embarrassing for the patients, and resolution of both a previous failed sympathectomy and recurrent hyperhidrosis is important.

METHODS

From September 1995 to January 1998, 24 patients (11 men and 13 women; mean age, 28.2 years) underwent repeat transthoracic sympathectomy (TES). The repeat TES was performed with patients under general anesthesia using either a standard single-lumen endotracheal tube (12 patients) or a double-lumen endotracheal tube (12 patients). Ablation of T2 and T3 ganglia and any Kuntz fiber was performed in treating patients with palmar hyperhidrosis, and a similar procedure was performed on T3 and T4 ganglia for patients with axillary hyperhidrosis.

RESULTS

The reasons for failure of the previous TES were pleural adhesion (14/24), intact T2 ganglion (5/24), aberrant venous arch drainage to the superior vena cava (2/24), incomplete interruption of sympathetic nerve (2/24), and possible reinnervation (1/24). The mean operation time was 28 min (range, 18-72 min). In all, 23 patients had a satisfactory result, without recurrence of palmar or axillary hyperhidrosis. The mean follow-up time was 22 months (range, 5-30 months). The average hospital stay was 1.8 days. There was no surgical mortality.

CONCLUSION

Repeat TES is a safe and effective method for treating both an unsuccessful sympathectomy and recurrent palmar or axillary hyperhidrosis.

Assessment of a new quantitative ultrasound calcaneus measurement: precision and discrimination of hip fractures in elderly women compared with dual X-ray absorptiometry

The incidence of osteoporotic hip fracture increases in postmenopausal women with low hip bone mineral density (BMD). Dual X-ray absorptiometry (DXA) is the most commonly used technique for the assessment of bone status and provides good measurement precision. However, DXA affords little information about bone architecture. Quantitative ultrasound (QUS) systems have been developed to evaluate bone status for assessment of fracture risk. Our study was designed to assess a new QUS system from Hologic, the Sahara; to compare it with a previous model, the Walker-Sonix UBA 575+; and to investigate whether it is able to discriminate between women with and without fracture. Using both ultrasound devices, the measurements were performed at the heels of 33 postmenopausal women who had recently sustained hip fracture. A control group of 35 age-matched postmenopausal women was recruited for comparison. The total, neck and trochanter femoral BMD values were assessed using DXA for both groups. QUS and DXA measurements were significantly lower in fractured patients (p < 0.005) than in the control group. The short-term, mid-term and standardized short-term precisions were used to evaluate the reproducibility of the two QUS systems. The Sahara showed a better standardized coefficient of variation for broadband ultrasound attenuation (BUA) than did the UBA 575+ (p < 0.001). The correlation of BUA and speed of sound (SOS) between the two QUS devices was highly significant, with an r value of 0.92 for BUA and 0.91 for SOS. However, the correlation between DXA and ultrasound parameters ranged from 0.28 to 0.44. We found that ultrasound measurements at the heel were significant discriminators of hip fractures with odds ratios (OR) ranging from 2.7 to 3.2. Even after adjusting the logistic regressions for total, neck or trochanter femoral BMD, QUS variables were still significant independent discriminators of hip fracture. The areas under the ROC curves of each ultrasound parameter ranged from 0.75 to 0.78, and compared very well with femoral neck BMD (p > 0.05). In conclusion, our study indicated that the calcaneal QUS variables, as measured by the Sahara system can discriminate hip fracture patients equally as well as hip DXA.

Comparison of six calcaneal quantitative ultrasound devices: precision and hip fracture discrimination

Quantitative ultrasound (QUS) is now accepted as a useful tool in the management of osteoporosis. There are a variety of QUS devices clinically available with a number of differences among them, including their coupling methods, parameter calculation algorithms and sites of measurement. This study evaluated the abilities of six calcaneal QUS devices to discriminate between normal and hip-fractured subjects compared with the established method of dual-energy X-ray absorptiometry (DXA). The short-term and mid-term precisions of these devices were also determined. Thirty-five women (mean age 74.5+/-7.9 years) who had sustained a hip fracture within the past 3 years, and 35 age-matched controls (75.8+/-5.6 years) were recruited. Ultrasound measurements were acquired using six ultrasound devices: three gel-coupled and three water-coupled devices. Bone mineral density was measured at the hip using DXA. Discrimination of fracture patients versus controls was assessed using logistic regression analysis (expressed as age- and BMI-adjusted odds ratios per standard deviation decrease with 95% confidence interval) and receiver operating characteristics (ROC) curve analysis. Measurement precision was standardized to the biological range (sCV). The sCV ranged from 3.14% to 5.5% for speed of sound (SOS) and from 2.45% to 6.01% for broadband ultrasound attenuation (BUA). The standardized medium-term precision ranged from 4.33% to 8.43% for SOS and from 2.77% to 6.91% for BUA. The pairwise Pearson correlation coefficients between different devices was highly significant (SOS, r = 0.79-0.93; BUA, r = 0.71-0.92). QUS variables correlated weakly, though significantly, with femoral BMD (SOS, r = 0.30-0.55; BUA, r = 0.35-0.61). The absolute BUA and SOS values varied among devices. The gel-coupled devices generally had a higher SOS than water-coupled devices. Bone mineral density (BMD) and BUA were weakly correlated with weight (r = 0.48-0.57 for BMD and r = 0.18-0.54 for BUA), whereas SOS was independent of weight. All the QUS devices gave similar, statistically significant hip fracture discrimination for both SOS and BUA measures. The odds ratios for SOS (2.1-2.8) and BUA (2.4-3.4) were comparable to those for femoral BMD (2.6-3.5), as were the area under the curve (SOS, 0.65-0.71; BUA, 0.62-0.71; BMD, 0.65-0.74) from ROC analysis. Within the limitation of the sample size all devices show similar diagnostic sensitivity.

Sub-Nanosecond Lifetime Measurement Using the Recoil-Distance Method

The electromagnetic properties of low-lying nuclear states are a sensitive probe of both collective and single-particle degrees of freedom in nuclear structure. The recoil-distance technique provides a very reliable, direct and precise method for measuring lifetimes of nuclear states with lifetimes ranging from less than one to several hundred picoseconds. This method complements the powerful, but complicated, heavy-ion induced Coulomb excitation technique for measuring electromagnetic properties. The recoil distance technique has been combined with heavy-ion induced Coulomb excitation to study a variety of problems. Examples discussed are: study of the two-phonon triplet in (110)Pd, coupling of the β and γ degrees of freedom in (182,184)W, highly deformed γ bands in (165)Ho, octupole collectivity in (96)Zr, and opposite parity states in (153)Eu. Consistency between the Coulomb excitation results and the lifetime measurements confirms the reliability of the complex analysis often encountered in heavy-ion induced Coulomb excitation work.

The preclinical pharmacologic study of dopamine transporter imaging agent [99mTc]TRODAT-1

The purpose of this study was to investigate the pharmacologic characteristics of TRODAT-1 (2beta-((N,N'-bis(2-mercaptoethyl)ethylene diamino)methyl), 3beta-(4-chlorophenyl)tropane) labeled with [99mTc] as an imaging agent for dopamine transporter (DAT). Radiochemical purity of [99mTc]TRODAT-1 was over 90%. The partition coefficients in octanol and buffer were 2.12 and 2.19 at pH 7.0 and 7.4, respectively. Animal studies have been performed in rats, rabbits, and normal and hemi-Parkinsonian model monkeys. Biodistribution displayed moderate uptake in rat brain (0.28 %ID/organ at 2 min) and the striatal uptake was 0.193, 0.142, and 0.136 %ID/g at 2, 60, and 120 min, respectively. The ratios of striatal/cerebellar (ST/CB) uptake were 2.4, 4.45, and 2.45 %ID/g at 60, 120, and 240 min, respectively. The major radioactivity was excreted by the hepatobiliary system. Blood clearance kinetics was performed in rabbits, and the initial half-life of 1.18 min and late half-life of 367.8 min were obtained. Brain single photon emission computed tomography imaging studies in normal monkeys showed the ratios of ST/CB uptake were 1.56-2.0 %ID/g and indicated that both uptake and retention in the striatal area were associated with the DAT. The imaging of hemi-Parkinsonian model monkeys also displayed the expected selectivity, the highest uptake being observed in the basal ganglia area of the normal side. Thereby, it is suggested that [99mTc]TRODAT-1 is a safe and useful imaging agent for localization of the presynaptic DAT in the brain.

Vertebral fractures in osteoporosis: a new method for clinical assessment

Vertebral fractures are the most common consequence of osteoporosis, and are an important risk factor for subsequent fractures. Patients with reduced bone mineral density (BMD) and vertebral fractures have significantly increased risk for future fractures, indicating great potential for the combined use of fracture assessment and BMD in risk evaluation. Despite the established importance of fractures, however, vertebral assessment is not typically performed in the clinical evaluation of patients at risk for osteoporosis. Radiographs are the accepted standard for assessment of fractures, but are rarely obtained in osteoporosis assessment for a variety of practical reasons, including cost, radiation dose, and the lack of office-based radiological facilities. Clinical assessment of fractures is difficult because most are asymptomatic. Consequently, this strong risk factor for osteoporotic fractures is often overlooked. High-resolution lateral spine images, obtained on advanced fan-beam dual X-ray absorptiometry (DXA) systems, provide a practical, low-radiation dose, point-of-care methodology for assessment of vertebral fractures, and have the potential to address this important clinical need. In this article, we review the importance of vertebral fractures and the methods of assessing them. We also review clinical data supporting the feasibility of visual evaluation of lateral spine images obtained using a fan-beam DXA system, and discuss the potential positive impact of this new methodology on clinical patient evaluation.

Clinicopathologic analysis of malignant melanoma in Taiwan

BACKGROUND

Malignant melanoma is the leading cause of death among skin cancers in western countries. However, the incidence, histologic subtypes, and tumor behaviors are quite different in Asians and people of color.

OBJECTIVE

Our purpose was to define the tumor behaviors and possible prognostic predictors of melanomas based on a Taiwanese patient population.

METHODS

From the 65 patients diagnosed with melanoma at Veterans General Hospital, Taichung, we analyzed mean age at onset, gender, histologic subtypes, tumor thickness, level of invasion, primary tumor locations, and metastatic sites. Univariate analysis and multivariate analyses for survival, according to clinical and histologic tumor behaviors, were performed by means of Cox proportional hazard model. Survival curves were plotted by Kaplan-Meier method.

RESULTS

Fifty-one cutaneous melanomas were identified and analyzed by both clinical behaviors and histology. Acral lentiginous melanoma was the most common type (54.9%), followed by nodular melanoma (29.4%), superficial spreading melanoma, and lentigo maligna melanoma. Univariate analysis for overall survival of melanoma revealed that age at onset older than 55 years, male gender, ulceration of tumor, and thicker tumor have the tendency to poorer prognosis, but without significant differences. The advanced stages (III and IV) and histologic subtypes other than acral lentiginous melanoma predicted a poorer survival with significant differences. Multivariate analysis demonstrated advanced stages, and histologic subtypes were the independent risk factors for poor prognosis.

CONCLUSION

We proposed that histologic subtypes other than acral lentiginous melanoma and advanced stages have a poorer prognosis with significant differences.

A novel chromosomal locus of enteropathogenic Escherichia coli (EPEC), which encodes a bfpT-regulated chaperone-like protein, TrcA, involved in microcolony formation by EPEC

The bfpTVW operon, also known as the per operon, of enteropathogenic Escherichia coli (EPEC) is required for the transcriptional activation of the bfp operon, which encodes the major subunit and assembly machinery of bundle-forming pili (BFP). An immobilized T7-tagged BfpT fusion protein that binds specifically to upstream promoter sequences of bfpA and eae was used to 'fish out' from a promoter library other EPEC chromosomal fragments that are bound by the BfpT protein. After screening for promoters exhibiting bfpTVW-dependent expression, one was identified that was positively regulated by bfpTVW and that is not present in the chromosomes of two non-virulent E. coli laboratory strains, DH5alpha and HB101. Further analysis of this positively regulated promoter in EPEC showed that it resided within a 4.9 kb sequence that is not present in E. coli K12. This locus, located downstream of the potB gene, was found to contain four open reading frames (ORFs): bfpTVW-activated promoter was localized upstream of ORF1. An ORF1 knockout mutant produced less of the BFP structural subunit (BfpA) and formed smaller than normal adherent microcolonies on cultured epithelial cells; however, this mutation did not affect bfp transcription. An ORF1-His6 fusion protein specifically bound the preprocessed and mature forms of the BfpA protein and thus appears to stabilize the former within the cytoplasmic compartment. ORF1 therefore is a newly isolated EPEC chromosomal gene that encodes a chaperone-like protein involved in the production of BFP. Hence, ORF1 was designated trcA (bfpT-regulated chaperone-like protein gene). The TrcA protein also specifically bound 39 kDa and 90 kDa proteins that are expressed by EPEC but not by E. coli K12. The 90 kDa protein was revealed to be intimin, a protein product of the eae gene, which is required for the EPEC attaching/effacing phenotype, suggesting a direct interaction of TrcA with intimin in the cytoplasmic compartment.

Suppression of tumorigenicity in cervical carcinoma HeLa cells by an episomal form of adeno-associated virus

To compare the oncosuppressive activity of integrated and episomal adeno-associated virus (AAV), two Epstein-Barr virus (EBV) derived episomal form vectors, p205 and p220, were used to generate plasmids containing episomal AAV. HeLa cells transfected with p205, p220, and the plasmids with forward (pA205-1, pA220-1) and reverse (pA205-1, pA220-2) orientation of inserted AAV DNA were designated H205, H220, HA205-1, HA220-1, HA205-1, and Ha220-2, respectively. The respective average copy numbers of pA205 and pA220 per cell are 4.9-6.9 and 4.3. The AAV-transfected HeLa cells displayed growth inhibition when compared to parental and the vector-transfected HeLa cells. Nude mice assay showed that the tumor size from HA205-1 and HA205-2 cells were 11.3 and 22.6%, and those from HA220-1 and HA220-2 cells were 54.8 and 57.3%, respectively, when compared to parental HeLa cells. HA205-1 cells containing forward AAV insert exerted more oncosuppressive effect than HA205-2 cells containing reverse AAV insert. Our data indicate that the episomal AAV can exert oncosuppressive activity as compared to the integrated AAV in HeLa cells.