Gender Self-Identification: Opinions About Transgender Women from a National Online Survey in Taiwan

Gender self-identification (transgender) is not permitted in most Asian countries. In Taiwan, individuals recognized as transgender must meet requirements mandated by the Gender Recognition Act. Currently, lifting the requirement for proof of sex-reassignment surgery is pending. The aim of this study was to survey a large sample of Taiwanese to gain a better understanding of the general population's attitudes toward gender self-identification. A self-report survey, entitled "Opinions of Gender Self-Identification," collected demographic information and responses (agree = 1, disagree = 0) to 14 statements about transgender women and women's safety, personal rights, and the law; one statement discussed rights of transgender men to give birth; total scores ranged from 0 to 14. The online survey was distributed to non-government organizations across Taiwan and the Taiwanese islands and was available between April 16 and 30, 2022. Most of the 10,158 respondents were female (77.4%); ages of respondents ranged from 15 to > 65 years. The mean total score was 0.95 ± 2.27, indicating respondents strongly disagreed with support for transgender females; 91.56% disagreed with all statements. Although there were significant differences in scores between parents and non-parents, and those ≤ 35 years versus ≥ 36 years (p < .01), all strongly disagreed with gender self-identification. Given the majority of respondents were females, survey findings should be regarded with caution. Public acceptance of gender self-identification requires support from its residents. Our findings suggest that gender self-identification has not begun to approach even a moderate level of public support among survey respondents.

Legalization of marijuana or not? Opinions from over 38,000 residents in Taiwan

BACKGROUND

Marijuana is legal in many Western countries and Thailand. In Taiwan, Marijuana remains a category-2 narcotic; however, some legislative candidates recently advocated legalization of medical marijuana. This study surveyed a large sample of Taiwanese to gain a better understanding of the public's knowledge and attitudes towards legalizing marijuana.

METHODS

This cross-sectional mixed-methods study included demographic data and responses to a survey questionnaire, "Knowledge and Attitudes of Legalizing Marijuana" (KALM). The survey included 15 statements about four categories: public health, social impact, medical applications of THC (Δ9-tetrahydrocannabinol), and legal and tax consequences; and two yes/no questions about medical use and legalization of marijuana. Knowledge was scored as disagree = 0, no knowledge = 2, or agree = 4; attitude was scored from 0 = very unimportant to 4 = very important. Responses to an open-ended question asking for additional comments/concerns were analysed with content analysis. The survey was conducted from February 15 to March 1, 2023.

RESULTS

Data were analysed from 38,502 respondents, aged 15 to > 56 years. Most were female (67.1%) and parents (76.4%). Scores were higher for respondents who were parents, religious, ≥ 36 years of age, had a high-income status, no history of substance abuse, knowledge of medical marijuana, and did not support legalization of marijuana. Medical personnel had greater knowledge of marijuana, but their attitude indicated they viewed legalization as less important. In the open-ended question, many respondents requested more information about marijuana be provided to the public before considering legalization.

CONCLUSIONS

Taiwanese respondents considered legalization of marijuana a significant concern, especially as it relates to impacts on public health.

Prevalence and Comorbidity of Gender Dysphoria in Taiwan, 2010-2019

Gender dysphoria (GD) is a condition in which a person exhibits marked incongruence between their expressed or experienced gender and their sex assigned at birth. The last survey of individuals with GD in Taiwan was conducted approximately 10 years ago. In this study, we investigated the prevalence of GD in Taiwan within the last 10 years as well as comorbidities. A retrospective medical record review was performed for all patients in the database of the Health and Welfare Data Science Center covered by National Health Insurance in Taiwan from January 2010 until December 2019. The study population of persons with GD was defined as individuals who had been diagnosed with transsexualism (transgender or transsexual) or gender identity disorders. Our review found case numbers and prevalence of GD in 2019 were about twice that of patients in 2010 for both assigned males and assigned females at birth. Case numbers for 2010 versus 2019 were 440 versus 867 for assigned males at birth, and 189 versus 386 for assigned females at birth. The 1-year prevalence for 2010 versus 2019 was 3.8/100,000 versus 7.4/100,000 for assigned males at birth, and 1.6/100,000 versus 3.2/100,000 for assigned females at birth. Comorbidities of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and psychosis were more likely in children with GD younger than 12 years of age; comorbid depression was more likely in adolescents and adults with GD. Improvements in social and mental health support should be provided to help address these comorbidities of ADHD, ASD, and depression among individuals with GD.

α-Actinin-4 recruits Shp2 into focal adhesions to potentiate ROCK2 activation in podocytes

α-Actinin-4 is crucial in the regulation of Shp2 FA targeting to enhance ROCK2-mediated actomyosin contractility and thereby strengthening cell adhesion and cytoskeletal architecture in podocytes.

Cell–matrix adhesions are mainly provided by integrin-mediated focal adhesions (FAs). We previously found that Shp2 is essential for FA maturation by promoting ROCK2 activation at FAs. In this study, we further delineated the role of α-actinin-4 in the FA recruitment and activation of Shp2. We used the conditional immortalized mouse podocytes to examine the role of α-actinin-4 in the regulation of Shp2 and ROCK2 signaling. After the induction of podocyte differentiation, Shp2 and ROCK2 were strongly activated, concomitant with the formation of matured FAs, stress fibers, and interdigitating intracellular junctions in a ROCK-dependent manner. Gene knockout of α-actinin-4 abolished the Shp2 activation and subsequently reduced matured FAs in podocytes. We also demonstrated that gene knockout of ROCK2 impaired the generation of contractility and interdigitating intercellular junctions. Our results reveal the role of α-actinin-4 in the recruitment of Shp2 at FAs to potentiate ROCK2 activation for the maintenance of cellular contractility and cytoskeletal architecture in the cultured podocytes.

Establishment of feline in-house reference intervals for hematologic and biochemical parameters and potential age-related differences

Reference intervals (RIs) are one of the essential elements in the procedure of disease diagnosis. This is especially true for feline species in which RI is less available than in canine species. RIs are affected by biological, geographical and instrumental factors, yet published RIs with incomplete background are popularly used. Inappropriate interpretations of RIs may affect classification of disease and subsequent treatment. In this study, we demonstrated the step-by-step establishment of feline RIs following the American Society for Veterinary Clinical Pathology (ASVCP) reference interval guideline. A total of 51 parameters were examined, including 20 hematology and 31 biochemistry parameters, and the results were compared to one local RI and two foreign RIs. Overall, about 29% (10/35) of tested parameters were different form local RIs and 60% (30/50) were different from the two foreign RIs, highlighting geographical variations. A higher upper reference limit (URL) in red blood cell count (RBC), hematocrit (Hct), Hemoglobin (Hgb), albumin, creatinine and lower URL in potassium and white blood cell count (WBC) were identified, which may impact the interpretation. In addition, statistical analysis of age and gender were factored separately and indicated that 10 parameters were significantly higher in the adult group. For the impact of gender, percentage of basophil and total iron-binding capacity (TIBC) were lower in female and male cats, respectively. In conclusion, we have demonstrated that it is desirable to establish in-house RIs or RIs of local sources. An age specific RI for the geriatric feline population is advisable for better diagnosis and monitoring the disease.

Blue light irradiation triggers the antimicrobial potential of ZnO nanoparticles on drug-resistant Acinetobacter baumannii

Photodynamic inactivation (PDI) is a non-invasive and safe therapeutic method for microbial infections. Bacterial antibiotic resistance is caused by antibiotics abuse. Drug-resistant Acinetobacter spp. is a serious problem in hospitals around the world. These pathogens from nosocomial infections have high mortality rates in frailer people, and Acinetobacter spp. is commonly found in immunocompromised patients. Visible light is safer than ultraviolet light (UV) for PDI of nosocomial pathogens with mammalian cells. Zinc oxide nanoparticles (ZnO-NPs) were used in this study as an antimicrobial agent and a photosensitizer. ZnO is recognized as safe and has extensive usage in food additives, medical and cosmetic products. In this study, we used 0.125 mg/ml ZnO-NPs combined with 10.8 J/cm² blue light (BL) on Acinetobacter baumannii (A. baumannii) that could significantly reduce microbial survival. However, individual exposure to ZnO-NPs does not affect the viability of A. baumannii. BL irradiation could trigger the antimicrobial ability of ZnO nanoparticles on A. baumannii. The mechanism of photocatalytic ZnO-NPs treatment for sterilization occurs through bacterial membrane disruptions. Otherwise, the photocatalytic ZnO-NPs treatment showed high microbial eradication in nosocomial pathogens, including colistin-resistant and imipenem-resistant A. baumannii and Klebsiella pneumoniae. Based on our results, the photocatalytic ZnO-NPs treatment could support hygiene control and clinical therapies without antibiotics to nosocomial bacterial infections.

Plasma indoxyl sulfate concentration predicts progression of chronic kidney disease in dogs and cats

Indoxyl sulfate is a protein-bound uremic toxin that increases as the severity of impaired renal function increases in humans, laboratory animals, dogs and cats. An elevation of indoxyl sulfate is related to prognosis among people with chronic kidney disease. However, whether indoxyl sulfate is able to predict the progression of chronic kidney disease in dogs and cats has not been previously studied. In the present study, 58 cats and 36 dogs with chronic kidney disease were enrolled. Plasma indoxyl sulfate was measured by high performance liquid chromatography. Renal progression was defined as an increase by one International Renal Interest Society (IRIS) stage and/or a rise in serum creatinine concentration of 0.5mg/dL during the same stage within a 3-month period. Compared with the non-progression groups, across different stages of renal failure, the baseline plasma indoxyl sulfate concentration was increased in the renal progression group (P<0.05), especially for IRIS stages 2 and 3 animals. The area under the receiver operator characteristic curves of indoxyl sulfate, when predicting renal progression, was above 0.75 for both dogs and cats. Indoxyl sulfate concentrations were also correlated with the increase of blood urea nitrogen, serum creatinine, and phosphate and the decrease of hematocrit among cats; while in dogs, concentrations were only correlated with the increase of phosphate concentrations. Indoxyl sulfate served as a biomarker of progression risk in dogs and cats with chronic kidney disease.

Detection of indoxyl sulfate levels in dogs and cats suffering from naturally occurring kidney diseases

Indoxyl sulfate (IS), a protein-bound uraemic toxin, has been found to accumulate in the serum of people with renal diseases and is associated with free radical induction, nephrotoxicity cardiovascular toxicity, and osteoblast cytotoxicity. Although IS has been studied in humans and in experimental models, the role of IS in dogs and cats with kidney disease has not been investigated. A high performance liquid chromatography system was applied to detect plasma IS concentrations in non-azotaemic animals (63 dogs, 16 cats) and in animals with renal azotaemia (66 dogs, 69 cats). The IS levels of azotaemic animals were significantly higher (P <0.01) than those of non-azotaemic animals (median [IQR] 20.4 (9.5) mg/L vs. 7.2 (8.8) mg/L for dogs; median [IQR] 21 (18.9) mg/L vs. 14.8 (12.3) mg/L for cats). The IS level was significantly correlated with blood urea nitrogen, serum creatinine and phosphate concentrations. Dogs with acute kidney injury had significantly higher IS levels (P <0.01) than those with chronic kidney diseases (CKD) (median [IQR] 57.7 (40.8) mg/L vs. 17.7 (25.1) mg/L). When CKD was graded using the International Renal Interest Society (IRIS) staging system, IS levels were correlated with CKD severity in both dogs and cats. The IS concentration is directly related to loss of renal function. Further studies are necessary to determine whether measurement of IS provides any additional diagnostic or prognostic information in dogs and cats with kidney disease.

Associations between serum total bilirubin levels and functional dependence in the elderly

BACKGROUND

Many studies support the role of bilirubin as a cytoprotector in chronic inflammatory diseases, such as stroke and atherosclerosis.

AIM

To investigate the relationship between serum total bilirubin levels and functional dependence in older adults.

METHODS

Data from the National Health and Nutrition Examination Survey (1999-2002) pertaining to 2235 old adults were analysed. All participants had given a household interview, providing information of five major domains on self-reported functional status (activities of daily living, instrumental activities of daily living, leisure and social activities, lower extremity mobility and general physical activities), had completed serum total bilirubin measurement, and a questionnaire regarding personal health. Poor performance was defined as experiencing difficulty with one or more items in a given domain. Functional dependence was defined as having three or more poor performances in the five major domains. Multiple logistic regression was performed together with quartile-based stratified odds ratio (OR) comparison and trend tests.

RESULTS

The OR of functional dependence for each standard deviation increment in the serum total bilirubin level was 0.56 (P = 0.002). After additional adjustment, the inverse association remained essentially unchanged. In quartile-based analysis, participants with higher quartiles of serum total bilirubin tended to have lower ORs of functional dependence. The trends of lower likelihood of functional dependence across increasing quartiles of the serum total bilirubin level were statistically significant (P < 0.05 for all trends).

CONCLUSIONS

Higher serum total bilirubin levels were associated with lower likelihood of functional dependence in older adults.

Building blocks for the development of an interface for high-throughput thin layer chromatography/ambient mass spectrometric analysis: a green methodology

Interfacing thin layer chromatography (TLC) with ambient mass spectrometry (AMS) has been an important area of analytical chemistry because of its capability to rapidly separate and characterize the chemical compounds. In this study, we have developed a high-throughput TLC-AMS system using building blocks to deal, deliver, and collect the TLC plate through an electrospray-assisted laser desorption ionization (ELDI) source. This is the first demonstration of the use of building blocks to construct and test the TLC-MS interfacing system. With the advantages of being readily available, cheap, reusable, and extremely easy to modify without consuming any material or reagent, the use of building blocks to develop the TLC-AMS interface is undoubtedly a green methodology. The TLC plate delivery system consists of a storage box, plate dealing component, conveyer, light sensor, and plate collecting box. During a TLC-AMS analysis, the TLC plate was sent to the conveyer from a stack of TLC plates placed in the storage box. As the TLC plate passed through the ELDI source, the chemical compounds separated on the plate would be desorbed by laser desorption and subsequently postionized by electrospray ionization. The samples, including a mixture of synthetic dyes and extracts of pharmaceutical drugs, were analyzed to demonstrate the capability of this TLC-ELDI/MS system for high-throughput analysis.

Cultural condition affecting the growth and production of β-galactosidase by Bifidobacterium longum CCRC 15708 in a jar fermenter

In the present study, the growth and production of beta-galactosidase by Bifidobacterium longum CCRC 15708 in a 5-L jar fermenter as influenced by cultivation temperature (27-42 degrees C), medium pH (4.5-7.5) and agitation speed (5-200 rpm) were evaluated. In general, it was found that a cultivation temperature of 37 degrees C proved optimal for both growth and beta-galactosidase production by the test organism. Although the growth of the test organism was the highest in the culture with pH controlled at 4.5-6.5, the culture with pH controlled at 6.5 resulted in the highest production of beta-galactosidase. Further, agitation at 100 rpm or more was found to enhance both the growth and production of beta-galactosidase. Fermentation conducted in a jar fermenter having the pH of the culture medium, the cultivation temperature, and the agitation speed controlled at 6.5, 37 degrees C, and 100 rpm, respectively, a maximum beta-galactosidase activity of 36.7 U/ml and a maximum transgalactosylation activity of 0.49 U/ml was achieved in 10 h of fermentation. There are ca 2.0 and 12.3 fold greater than the reported maximum beta-galactosidase and transgalactosylation activity, respectively, produced by B. longum CCRC 15708 in a flask culture system.

Enzymatic production of galactooligosaccharides by beta-galactosidase from Bifidobacterium longum BCRC 15708

The production of galactooligosaccharides (GOSs) by transgalactosylation using beta-galactosidase from Bifidobacterium longum BCRC 15708 was studied. Other than lactose, galactose, and glucose, two types of GOSs, tri- and tetrasaccharides, were formed after beta-galactosidase action on 40% lactose. Trisaccharides were the major type of GOS formed. Generally, an increase of the initial lactose concentration in the reaction mixture resulted in a higher GOS production. A maximum yield of 32.5% (w/w) GOSs could be achieved from 40% lactose solution at 45 degrees C, pH 6.8, when the lactose conversion was 59.4%. The corresponding productivity of GOSs was 13.0 g/(L.h). Transgalactosylation activity of beta-galactosidase from a test organism showed a relatively lower sensitivity toward glucose and galactose than that from other organisms. The addition of 5% or 10% glucose or galactose to the reaction mixture did not significantly (p>0.05) reduce the transgalactosylation reaction of beta-galactosidase.

Study on the species-specificity of Isospora michaelbakeri by experimental infection

Isospora michaelbakeri is one of the Isospora species most commonly found in the wild field, which can cause severe infection and mortality in young sparrows. In this study, we selected I. michaelbakeri (Chung Hsing strain) as a pathogen to orally inoculate russet sparrows (Passer rutilans), spotted munia (Lonchura punctulata), canary (Serinus canaria), Java sparrows (Padda oryzivora), chicken (Gallus domesticus), ducks (Anas platyrhynchos) and BALB/c mice. The results indicated that I. michaelbakeri infected only russet sparrows. Infected sparrows displayed lethargy, muscular weakness and fluffy feathers, followed by rapid death. Liver and spleen enlargement was seen in the infected birds. Schizonts were identified in thin smears from the venous blood, enlarged livers and spleens. Histopathological examination revealed schizonts and merozoites from the liver and spleen of infected russet sparrows, but not from other species experimentally inoculated with I. michaelbakeri in the present study.

Characterization of Bacterial Susceptibility Isolates in Sixteen Dairy Farms in Taiwan

Bacteria were isolated from dairy cows, dairy farm environments, and dairy workers in 2 geographically different areas of eastern and northern Taiwan. Isolates were evaluated for antimicrobial susceptibility and the phylogenetics of isolated Escherichia coli O157:H7 were characterized. A total of 1,346 bacteria were identified, including 226 E. coli, 30 Pseudomonas spp. (7 Pseudomonas aeruginosa), 259 other gram-negative bacteria, 271 Enterococcus spp., 314 Staphylococcus spp., 195 Streptococcus spp., and 51 other gram-positive bacteria. Among them, 88% (1,184/1,346) of the isolates were resistant to sulfadimethoxine. The percentages of gram-negative bacteria resistant to oxy-tetracycline and streptomycin were 48% (249/515) and 78% (404/515), respectively. Gram-positive bacteria isolated from eastern Taiwan, the least polluted region of Taiwan, were found to have greater antimicrobial resistance than those isolated from northern Taiwan. Two E. coli O157:H7 from 2 different geographical areas were isolated. Both were vt2-positive but vt1-negative and had phylogenetic similarities of 82 and 67%, respectively, compared with previous isolates. Information on antimicrobial susceptibility revealed from this dairy farm survey may serve as a baseline for future studies and may also highlight the need to formulate better regulation strategies for the safe use of antimicrobials on food-producing farms.

Production of β-galactosidase by Bifidobacteria as influenced by various culture conditions

Beta-Galactosidase production by Bifidobacterium longum CCRC 15708, Bifidobacterium longum B6 and Bifidobacterium infantis CCRC 14633 was first examined with B. longum CCRC 15708 showing the highest production of beta-galactosidase and the highest specific activity. Further study with B. longum CCRC 15708 revealed that the highest level of beta-galactosidase was produced with lactose and yeast extract as carbon and nitrogen sources, respectively. Optimal enzyme production occurred at an initial pH of 6.5 and at 37 degrees C. Under these optimum culture conditions, a maximumbeta-galactosidase activity of 18.6 U/ml could be obtained after 16 h of fermentation in a medium contain 4% lactose, 3.5% yeast extract, 0.3% K2HPO4, 0.1% KH2PO4, 0.05% MgSO4.7H2O and 0.03% L-cysteine. The highest transgalactosylation activity was also detected in this culture after 14-16 h of fermentation.

Risk factors for cumulative mortality in broiler chicken flocks in the first week of life in Taiwan

(1) Factors influencing the survival of chickens in the first week of life in Taiwan were identified by modelling data from 63% of the annual national broiler production database (4769 broiler flocks). (2) Broiler chicks raised in rooms with open-curtain ventilation had the lowest mean first week cumulative mortality (CM), 1.30%, relative to those raised in rooms with negative pressure ventilation (1.42%) and water-cooled ventilation (1.37%). Increasing flock size reduced the CM. Broiler chicks shipped distances within 50 km had the lowest CM (1.22%), while broiler chicks raised in mountain areas showed the highest CM (1.65%). (3) Multiple regression analysis results indicate that ventilation type, flock size, shipping distance and delivery route influence CM in broiler chickens. Broiler chicks kept in rooms with negative pressure ventilation have an 11.22% greater CM compared to those in rooms with open-curtain ventilation. For each 1000-chicken increase in flock size, CM is reduced by 0.12%. For each kilometre increase in shipping distance, CM increases by 0.05%. Broiler chicks delivered via mountain routes show a 9.48% increase in CM compared to delivery via flat terrain. (4) Negative pressure ventilation and delivery via mountain routes are the most critical factors affecting the survival of chicks up to one week old.

Congener-specific polychlorinated biphenyls in cetaceans from Taiwan waters

During 2000 to 2001, a total of 73 blubber samples from 13 species of stranded or accidentally captured cetaceans were collected from Taiwan coastal waters for polychlorinated biphenyl (PCB) analysis. After homogenization, saponification, liquid-liquid extraction, and silica-gel solid-phase extraction, PCB concentrations were determined by gas chromatography/mass spectrometry. Total concentrations of 19 PCB congeners (SigmaPCBs) were between 0.23 microg/g lipid weight of Risso's dolphin to 33.73 microg/g lipid weight of rough-toothed dolphin. Pentachlorobiphenyls, hexachlorobiphenyls and heptachlorobiphenyls were the predominant PCB congeners species. PCB153 was the most abundant congener in all samples. The PCB153/SigmaPCBs consistently comprised between 20% to 30% of all congeners. The toxicity measured as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) were from 2.7 pg/g lipid weight of finless porpoise to 2,900 pg/g lipid weight of rough-toothed dolphin. PCB 118, a mono-ortho congener, was the largest contributor to TEQs. PCB concentrations and TEQs were higher in mature male than in immature male animals but were inconsistent in female animals because of a possible transferring of PCBs from maternal cetaceans to their offsprings during gestation and lactation. Stranded cetaceans had significantly higher PCB levels than by-catch cetaceans because of their higher lipid consumption during starvation or illness. From the collected samples, we also found that cetaceans from Taiwan waters had relatively lower PCB concentrations and TEQs than those from high-latitude areas.

Pharmacological evaluation of several major ingredients of Chinese herbal medicines in human hepatoma Hep3B cells

Long-dan-tan (Chinese name) is one of the most common herbal medicines used by Chinese people with chronic liver disease. Accumulated anecdotal evidence suggests that Long-dan-tan may show a beneficial effect in patients with hepatocellular carcinoma. Long-dan-tan is made from five plants: Gentiana root, Scutellaria root, Gardenia fruit, Alisma rhizome, and Bupleurum root. In this study, we have examined the cytotoxic effects of the five major ingredients isolated from the above plants, i.e. gentiopicroside, baicalein, geniposide, alisol B acetate and saikosaponin-d, respectively, on human hepatoma Hep3B cells. Annexin V immunofluorescence detection, DNA fragmentation assays and FACScan analysis of propidium iodide-staining cells showed that gentiopicroside, baicalein, and geniposide had little effect, whereas alisol B acetate and saikosaponin-d profoundly induced apoptosis in Hep3B cells. Alisol B acetate, but not saikosaponin-d, induced G2/M arrest of the cell cycle as well as a significant increase in caspase-3 activity. Interestingly, baicalein by itself induced an increase in H(2)O(2) generation and the subsequent NF-kappaB activation; furthermore, it effectively inhibited the transforming growth factor-beta(1) (TGF-beta(1))-induced caspase-3 activation and cell apoptosis. We suggest that alisol B acetate and saikosaponin-d induced cell apoptosis through the caspase-3-dependent and -independent pathways, respectively. Instead of inducing apoptosis, baicalein inhibits TGF-beta(1)-induced apoptosis via increase in cellular H(2)O(2) formation and NF-kappaB activation in human hepatoma Hep3B cells.

The cytotoxicity of jet fuel aromatic hydrocarbons and dose-related interleukin-8 release from human epidermal keratinocytes

Many jet fuel aromatic hydrocarbons are known carcinogens with the ability to both readily penetrate the skin with high absorptive flux and cause skin irritation. In order to evaluate the in vitro cutaneous toxicity of individual aromatic hydrocarbons in jet fuels and their potential for inducing skin irritation, we evaluated the LD(50), the highest non-cytotoxic (5% mortality) dose (HNTD), and interleukin-8 (IL-8) release activity of nine major jet fuel aromatic hydrocarbons in human epidermal keratinocytes (HEK). LD(50) ranged from 1.8 mM (0.03%) for cyclohexylbenzene to 82.9 mM (0.74%) for benzene, with a rank order potency of cyclohexylbenzene >trimethylbenzene >/=xylene >dimethylnaphthalene >ethylbenzene >toluene >benzene. The HNTD values ranged from 0.1 mM (0.001%) for cyclohexylbenzene to 48.2 mM (0.43%) for benzene. Naphthalene and methylnaphthalene could not be ranked in this comparison since their concentrations, presented as percentage saturation, were not comparable to the others presented as solutes in solution. There was a dose-related differential response in IL-8 release at 24 h. Toluene, xylene, trimethylbenzene, cyclohexylbenzene and dimethylnaphthalene significantly decreased IL-8 release at the respective HNTDs, while IL-8 release did not continue to decrease, or significantly increased (cyclohexylbenzene and dimethylnaphthalene), at the LD(50). IL-8 significantly increased with both doses of methylnaphthalene and naphthalene. The presence of hexadecane and mineral oil greatly attenuated the cytotoxicity elicited by individual aromatic hydrocarbons in HEK cells.

Potential application of gas chromatography/tandem mass spectrometry in the measurement of coeluting isomers

Despite the unprecedented popularity of separation chromatography, the measurement of coeluting isomeric chemicals remains an extremely difficult task. We developed an analytical scheme capable of measuring two coeluting isomers using a single chromatographic column and a gas chromatography/tandem mass spectrometry system. The protocol utilized two product ion fragments generated from a common parent ion associated with the isomers for quantitation. The utility of the analytical scheme was demonstrated with the measurements of several pairs of coeluting polychlorinated biphenyl (PCB) isomers in standard solutions and fish liver samples. Best results were given when a set of stringent constraints for the abundance ratio of the two product ion fragments was satisfied. Analyses of seven fish liver samples collected from nearshore San Diego, CA, indicated that the domain that had been previously reported to comprise PCB 153 and PCB 168 actually contained PCB 153 only. Although only a selected number of PCB congeners were examined, the results presented indicate that the analytical scheme has the potential to be used to determine the concentrations of all chromatographically coeluted isomers.

Continuous measurement of caffeine and two metabolites in blood and skeletal muscle of unrestrained adult horses by semi-automated in vivo microdialysis

Concentrations of caffeine (CA) and two metabolites were measured simultaneously in venous blood and splenius muscle of adult horses using a semi-automated in vivo microdialysis sampling technique. Dialysates from muscle and jugular vein were collected continuously for 48 h and drug levels were determined by high performance liquid chromatography (HPLC). Following i.v. injection, CA (3 mg/kg) attained a peak blood level of nearly 5400 +/- 600 ng/mL and decreased with a half-life of 15.3 +/- 0.7 h. Pharmacokinetic and statistical comparisons between CA concentrations in jugular dialysates and plasma samples revealed no significant differences between these sampling techniques. However, measurements in muscle and blood revealed unexpected pharmacokinetic differences, including significantly elevated concentrations of CA in muscle for 4 h following drug administration. In contrast, the CA metabolites theophylline (TP) and theobromine (TB) exhibited delayed appearances in muscle and blood with peak concentrations of 300 +/- 60 ng/mL (TP) and 150 +/- 50 ng/mL (TB) detected in both tissues 1 day following CA administration. This study demonstrates that our novel semi-automated microdialysis procedure for continuous monitoring of drug and metabolite levels may be useful for related studies in other domesticated large animal species.

Torsade de pointes induced by metoclopramide in an elderly woman with preexisting complete left bundle branch block

There is a growing list of drugs implicated in acquired long QT syndrome and torsade de pointes. However, the torsadogenic potential of metoclopramide, a commonly used antiemetic and prokinetic drug, has not been reported in the literature, despite its chemical similarity to procainamide. We report on a 92-year-old woman with preexisting complete left bundle branch block who developed torsade de pointes after intravenous and oral administration of metoclopramide. This patient also developed torsade de pointes when cisapride and erythromycin were given simultaneously. These two episodes were suppressed successfully after discontinuing the offending drugs and administering class IB drugs. This is the first documentation that metoclopramide provokes torsade de pointes clinically. Metoclopramide should be used cautiously in patients with a risk of torsade de pointes.

Crystallization and preliminary X-ray diffraction analysis of the 10 kDa C-terminal subdomain of 70 kDa heat-shock cognate protein

The 70 kDa heat-shock cognate protein (Hsc70) is a cytosolic molecular chaperone. It is composed of a 44 kDa N-terminal nucleotide-binding domain, an 18 kDa peptide-binding subdomain and a 10 kDa C-terminal subdomain. Single crystals of recombinant 10 kDa subdomain of rat Hsc70 have been obtained using ammonium sulfate as a precipitant at room temperature. The crystals diffract beyond 3.5 A using a synchrotron-radiation source at a wavelength of 1.0 A. The crystals belong to the hexagonal space group P6(1)22 or P6(5)22, with unit-cell parameters a = b = 119.0, c = 166.4 A.

Phase I/II trial evaluating combined radiotherapy and in situ gene therapy with or without hormonal therapy in the treatment of prostate cancer--a preliminary report

PURPOSE

To report the preliminary results of a Phase I/II study combining radiotherapy and in situ gene therapy (adenovirus/herpes simplex virus thymidine kinase gene/valacyclovir) with or without hormonal therapy in the treatment of prostate cancer.

METHODS AND MATERIALS

Arm A: low-risk patients (T1-T2a, Gleason score <7, pretreatment PSA <10) were treated with combined radio-gene therapy. A mean dose of 76 Gy was delivered to the prostate with intensity-modulated radiotherapy. Arm B: high-risk patients (T2b-T3, Gleason score >or=7, pretreatment PSA >or=10) were treated with combined radio-gene therapy and hormonal therapy. Hormonal therapy was comprised of a 4-month leuprolide injection and 2-week use of flutamide. Arm C: Stage D1 (positive pelvic lymph node) patients received the same regimen as Arm B, with the additional 45 Gy to the pelvic lymphatics. Treatment-related toxicity was assessed using Cancer Therapy Evaluation Program common toxicity score and Radiation Therapy Oncology Group (RTOG) toxicity score.

RESULTS

Thirty patients (13 in Arm A, 14 in Arm B, and 3 in Arm C) completed the trial. Median follow-up was 5.5 months. Eleven patients (37%) developed flu-like symptoms (Cancer Therapy Evaluation Program Grade 1) of fatigue and chills/rigors after gene therapy injection but recovered within 24 h. Four patients (13%) and 2 patients (7%) developed Grade 1 and 2 fever, respectively. There was no patient with weight loss. One patient in Arm B developed Grade 3 elevation in liver enzyme, whereas 11 and 2 patients developed Grade 1 and 2 abnormal liver function tests. There was no Grade 2 or above hematologic toxicity. Three patients had transient rise in creatinine. There was no RTOG Grade 3 or above lower gastrointestinal toxicity. Toxicity levels were as follows: 4 patients (13%), Grade 2; 6 patients (20%), Grade 1; and 20 patients (67%), no toxicity. There was 1 patient with RTOG Grade 3 genitourinary toxicity, 12 patients (40%) with Grade 2, 8 patients (27%) with Grade 1, and 9 patients (30%) with no toxicity. No patient dropped out from the trial or had to withhold treatment because of severe toxicity.

CONCLUSIONS

This is the first trial of its kind in the field of prostate cancer that aims to expand the therapeutic index of radiotherapy by combining in situ gene therapy. Initial experience has demonstrated the safety of this approach. There is no added toxicity to each therapy used alone. Long-term follow-up and larger cohort studies are warranted to evaluate long-term toxicity and efficacy.

Endoscopic variceal ligation for intractable esophageal variceal bleeding in children with idiopathic extrahepatic portal vein occlusion: report of three cases

Extrahepatic portal vein occlusion (EPVO) is an important cause of extrahepatic portal hypertension and variceal hemorrhage in children. We report 3 children with a diagnosis of EPVO and intractable esophageal variceal bleeding who underwent scheduled endoscopic variceal ligation (EVL) and prophylactic propranolol therapy for eradication of esophageal varices. Complete variceal obliteration was achieved in all 3 children following 3-4 treatment sessions. There were no significant complications or gastrointestinal hemorrhage during a follow-up period of 9 to 31 months after variceal eradication. In conclusion, EVL and long-term propranolol prophylaxis is safe and effective in eradicating bleeding esophageal varices in children with EPVO.

SCH-C (SCH 351125), an orally bioavailable, small molecule antagonist of the chemokine receptor CCR5, is a potent inhibitor of HIV-1 infection in vitro and in vivo

We describe here the identification and properties of SCH-C (SCH 351125), a small molecule inhibitor of HIV-1 entry via the CCR5 coreceptor. SCH-C, an oxime-piperidine compound, is a specific CCR5 antagonist as determined in multiple receptor binding and signal transduction assays. This compound specifically inhibits HIV-1 infection mediated by CCR5 in U-87 astroglioma cells but has no effect on infection of CXCR4-expressing cells. SCH-C has broad and potent antiviral activity in vitro against primary HIV-1 isolates that use CCR5 as their entry coreceptor, with mean 50% inhibitory concentrations ranging between 0.4 and 9 nM. Moreover, SCH-C strongly inhibits the replication of an R5-using HIV-1 isolate in SCID-hu Thy/Liv mice. SCH-C has a favorable pharmacokinetic profile in rodents and primates with an oral bioavailability of 50-60% and a serum half-life of 5-6 h. On the basis of its novel mechanism of action, potent antiviral activity, and in vivo pharmacokinetic profile, SCH-C is a promising new candidate for therapeutic intervention of HIV infection.

Acid adaptation and temperature effect on the survival of E. coli O157:H7 in acidic fruit juice and lactic fermented milk product

In this study, two strains of Escherichia coli O157:H7, (ATCC 43889 and ATCC 43895) were acid adapted at pH 5.0 in tryptic soy broth (TSB) for 4 h. Commercial products of mango juice (pH 3.2), asparagus juice (pH 3.6), Yakult--a diluted milk fermented drink (pH 3.6), and low-fat yoghurt (pH 3.9) were inoculated with acid-adapted or nonadapted cells of E. coli O157:H7. Survival of the inoculated E. coli O157:H7 in these commercial food products during storage at 25 or 7 degrees C was examined. It was found that although survival of the acid-adapted and nonadapted E. coli O157:H7 ATCC 43895 in asparagus juice during storage at 7 degrees C did not show marked difference, in general, acid adaptation and low temperature enhanced the survival of E. coli O157:H7 in both the commercial fruit juices tested. On the contrary, acid adaptation reduced the survival of both the strains of the test organism in Yakult and low-fat yoghurt stored at 7 degrees C. Besides, E. coli O157:H7 ATCC 43895 survived longer than ATCC 43889 in all the products examined, regardless of the storage temperature and acid adaptation.

Human B cell-attracting chemokine 1 (BCA-1; CXCL13) is an agonist for the human CXCR3 receptor

The CXC chemokine CXCL13, known as BCA-1 (B cell-attracting chemokine 1) or BLC (B-lymphocyte chemoattractant), has been identified as an efficacious attractant selective for B lymphocytes. The chemokine receptor BLR1 (Burkitt's lymphoma receptor 1)/CXCR5 expressed by all mature B cells has to date been identified as the only known receptor for BCA-1. As the loss of the BLR1/CXCR5 receptor is sufficient to disrupt organization of follicles in spleen and Peyer's patches, BCA-1 may act as a B cell homing chemokine. Nonetheless, BCA-1 has not been tested against all known chemokine receptors. In this study, we report that human BCA-1 competes with radiolabeled interferon gamma (IFN-gamma) inducible protein 10 (IP-10) for binding to the human CXCR3 receptor expressed in Ba/F3 and 293EBNA cell lines. Furthermore, human BCA-1 is an efficacious attractant for human CXCR3 transfected cells; BCA-1-induced chemotaxis is inhibited by a monoclonal antibody against human CXCR3. In these cells, as in human B lymphocytes expressing CXCR5, BCA-1 does not induce a calcium flux. Indeed, BCA-1 attenuates the calcium flux induced by IP-10. In addition, human BCA-1 is an agonist in stimulating GTP gamma S binding. Together these data suggest that human BCA-1 is a specific and functional G-protein-linked chemotactic ligand for the human CXCR3 receptor. The biological significance of this new finding is supported by our recent observation that human BCA-1 induces chemotaxis of activated T cells and the BCA-1-induced chemotaxis is inhibited by a monoclonal antibody against human CXCR3.

Effects of carbon and nitrogen sources, sodium chloride and culture conditions on cytotoxin production by Salmonella choleraesuis

The effects of carbon and nitrogen sources, incubation temperature, shaking speed, initial pH of culture broth as well as various concentration of NaCl on the production of cytotoxin by Salmonella choleraesuis SC-5 were evaluated in the present study. Results reveal that the optimal temperature, initial medium pH and shaking speed for cytotoxin production was 37 degrees C, pH 6.0-8.0 and 100 rpm, respectively. Tryptone was the best of the eight nitrogen sources tested for toxin production by S. choleraesuis. Among the nine carbon sources tested, S. choleraesuis produced a higher amount of cytotoxin in media containing glucose, fructose, galactose, sorbitol or mannitol as the carbon source. No toxin was detected in broths containing 4.0% or more sodium chloride in Tryptic soy broth (TSB). Cultures of S. choleraesuis in the medium containing 2.0% tryptone, 0.5% NaCl, 0.25% K2HPO4 and 0.25% of the best carbon source under the optimal conditions for 14 h resulted in the highest cytotoxin production. The Vero cell CD50 of S. choleraesuis lysate of cells grown under these optimal conditions was a titer of 589-758 per mg of lysate protein.

The crystal structure of a novel mammalian lectin, Ym1, suggests a saccharide binding site

Ym1, a secretory protein synthesized by activated murine peritoneal macrophages, is a novel mammalian lectin with a binding specificity to GlcN. Lectins are responsible for carbohydrate recognition and for mediating cell-cell and cell-extracellular matrix interactions in microbes, plants, and animals. Glycosaminoglycan heparin/heparan sulfate binding ability was also detected in Ym1. We report here the three-dimensional structure of Ym1 at 2.5-A resolution by x-ray crystallography. The crystal structure of Ym1 consists of two globular domains, a beta/alpha triose-phosphate isomerase barrel domain and a small alpha + beta folding domain. A notable electron density of sugar is detected in the Ym1 crystal structure. The saccharide is located inside the triose-phosphate isomerase domain at the COOH terminal end of the beta-strands. Both hydrophilic and hydrophobic interactions are noted in the sugar-binding site in Ym1. Despite the fact that Ym1 is not a chitinase, structurally, Ym1 shares significant homology with chitinase A of Serratia marcescens. Ym1 and chitinase A have a similar carbohydrate binding cleft. This study provides new structure information, which will lead to better understanding of the biological significance of Ym1 and its putative gene members.

Surface characteristics of Bacillus cereus and its adhesion to stainless steel

The ability of a Bacillus cereus strain, isolated from spoiled milk, to adhere to the surface of stainless steel chips was evaluated during its growth in diluted tryptic soy broth (DTSB). The number of cells that adhered to the surface increased markedly as the culture reached the end of the log phase and entered stationary phase, and continued to increase with further incubation. The surface properties of cells from the log, stationary, and late stationary phases were measured by hydrophobic interaction chromatography (HIC) and electrostatic interaction chromatography (ESIC). It was found that surface hydrophobicity of B. cereus vegetative cells from the late stationary phase was the highest followed by those from the stationary phase and the log phase cultures. While the vegetative cells prepared from stationary phase and log phase cultures, respectively, had the highest and the lowest surface charges. Adhesion of B. cereus vegetative cells to stainless steel was positively correlated with the cell surface hydrophobicity (R = 0.979). Surface hydrophobicity and surface positive charge noted on the spores harvested from diluted tryptic soy agar (DTSA) and Mn2+-tryptone glucose extract agar were higher than those harvested from the sucrose or lactose-added DTSA. A wide variation in the surface charge values was noted on the surface of various spores prepared from cultures grown on the four different media tested, while their ability to adhere to stainless steel chips in phosphate buffered saline (PBS) showed no significant difference (p > 0.05). Similarly, the number of spores or vegetative cells adhering to stainless steel suspended in PBS, milk or diluted milk (1000 x) did not differ significantly (p > 0.05).

Screening procedure from cattle feces and the prevalence of Escherichia coli O157:H7 in Taiwan dairy cattle

A procedure has been established for screening Escherichia coli O157:H7 from bovine feces. It consists of four steps: enrichment, selective culture, phenotyping and genotyping. Modified trypticase soy broth (mTSB) containing 20 microg/mL of novobiocin was used for the enrichment step. The selective culture step was done using sorbitol MacConkey agar containing 0.05 microg/mL of cefixime and 2.5 microg/mL of potassium tellurite. The phenotyping steps include: species confirmation as E. coli, serotyping to O157 and H7, and the detection of verocytotoxin (VT) production. Genotyping was made up of confirmation of the presence of the O157 antigen (rfb), the H7 antigen (ficC), the adherence factor (eaeA), hemolysin (hlyA), and VT production (vt I and vt II) by polymerase chain reaction. mTSB gave better enrichment for E. coli O157 than gram-negative (GN) broth. The detection limit for this screening procedure was 0.85 +/- 0.5 cfu/g. Using the screening procedure described above, E. coli O157 was found in four out of 3062 (0.13%) fresh bovine fecal specimens, and in two out of 78 (2.56%) dairy herds in Taiwan. Three out of the four detected strains were vt II producing E. coli O157:H7, while the other was E. coli O157:H7 which lacked VT-producing ability.

[The decision-making process of pregnant women with positive reaction to maternal serum screening for Down's syndrome when facing amniocentesis]

The purpose of this study was to explore the decision-making process of pregnant women with positive reaction to maternal serum screening for Down's syndrome when facing amniocentesis. Seventeen pregnant women consented to participation in this study. The data were collected through semi-structured interviews and analyzed using the grounded theory method. The findings revealed that there were four decision-making patterns. Each pattern could be grouped into three stages: post-acknowledgement transition, decision-making transition, and after-decision transition. Most participants had psychological reactions, which included shock, fear, nervousness, worry, sadness, and stress. Their concerns during the decision-making transition stage were: confirmation of health, normality, and safety of the fetus, fear of abortion due to amniocentesis, clarification of relations between amniocentesis and maternal serum screening, opinions from physicians and family members, and fear of artificial abortion for unhealthy fetus. Concerns during the after-decision transition stage were: information relating to amniocentesis, the management of an abnormal fetus, the place for amniocentesis, preparation before amniocentesis, and inadequate time for making a decision. Coping strategies were developed to deal with their concerns.

Influence of holding temperature on the growth and survival of Salmonella spp. and Staphylococcus aureus and the production of staphylococcal enterotoxin in egg products

In this study, growth and survival of Salmonella spp. and Staphylococcus aureus in steamed egg and scrambled egg held at 5, 18, 22, 37, 55 and 60 degrees C are investigated. The production of staphylococcal enterotoxin in steamed egg is also examined. Results reveal that Salmonella spp. and Staph. aureus in the egg products multiply best at 37 degrees C, followed closely by 22 and 18 degrees C. Neither pathogen showed growth in the egg products held at 5 degrees C. Initial inoculation dose, holding temperature and holding time affected the population of both organisms found in the egg products. Staphylococcal enterotoxin A (SEA) and B (SEB) are detected only in the egg products held at 37 or 22 degrees C. After holding at 37 degrees C for 36 h, scrambled egg inoculated with ca. 5.0 log cfu/g Staph. aureus contains the highest levels of SEA (> 64 ng/g) and SEB (> 64 ng/g). Although Salmonella spp. and Staph. aureus grow better in steamed eggs than in scrambled eggs, production of staphylococcal enterotoxin, in general, was higher in scrambled eggs than in steamed eggs. On the other hand, a repaid destruction of the test organisms in steamed eggs held at 60 degrees C was observed. Holding the steamed eggs at 60 degrees C, Salmonella spp. and Staph. aureus with an initial population of ca. 5.9 and 5.6 log cfu/g, respectively, reduced to a non-detectable level in 1 h.

Wavenumber Measurements of CO(2) Transitions in 1.5-µm Atmospheric Window Using an External-Cavity Diode Laser

Using an external-cavity diode laser (ECDL) as the light source, we have observed the spectrum of CO(2) in the 1.5-µm atmospheric window including the (30(0)1)(I) <-- (00(0)0) and (31(1)1)(I) <-- (01(1)0)(I) bands. Good signal-to-noise ratio allowed us to lock the frequency of our ECDL to the absorption line centers. Wavenumber measurements of the transitions with accuracy about 6.6 x 10(-4) cm(-1) are made with the help of a precision wavemeter calibrated to the accurate C(2)H(2) frequency references in the 1.5-µm wavelength region. Molecular constants are obtained by making the least-squares fits of the measured transition wavenumbers. The rotational and centrifugal distortion constants are consistent with the previous results using high-resolution Fourier transform spectroscopy. However, the band centers are different with previous results by several thousandth reciprocal centimeters. Copyright 2001 Academic Press.

Increased stability of nucleophosmin/B23 in anti-apoptotic effect of ras during serum deprivation

We obtained evidence that increased stability of nucleophosmin/B23 is involved in antiapoptotic effect of ras during serum deprivation. Nucleophosmin/B23 in serum-deprived (0% serum) NIH-3T3 cells was found to be highly unstable with a half-life less than 4 h. In contrast, nucleophosmin/B23 in serum-deprived ras-transformed (RAS-3T3) cells was as stable as that in serum-supplemented NIH-3T3 or RAS-3T3 cells. Treatment of RAS-3T3 cells with nucleophosmin/B23 antisense oligomer significantly potentiated the apoptosis induced by serum deprivation. Much less caspase-3 activity was noted in the lysate derived from serum-deprived RAS-3T3 cells compared with that in the lysate of serum-deprived NIH-3T3 cells. Cell permeable caspase-3 inhibitor added in the medium blocked the decrease of nucleophosmin/B23 and apoptosis induced by serum deprivation in NIH-3T3 cells. The inhibitor, on the other hand, promoted significant decrease of nucleolin/C23 in NIH-3T3 cells during serum deprivation. Unlike nucleolin/C23, down-regulation of nucleophosmin/B23 was thus not proliferation-dependent but caspase-3- and apoptosis-dependent. Our results indicate important relationships among ras, nucleophosmin/B23, activation of caspase-3, and induction of apoptosis.

Telomere-binding and Stn1p-interacting activities are required for the essential function of Saccharomyces cerevisiae Cdc13p

Yeast Saccharomyces cerevisiae Cdc13p is the telomere-binding protein that protects telomeres and regulates telomere length. It is documented that Cdc13p binds specifically to single-stranded TG(1-3) telomeric DNA sequences and interacts with Stn1p. To localize the region for single-stranded TG(1-3) DNA binding, Cdc13p mutants were constructed by deletion mutagenesis and assayed for their binding activity. Based on in vitro electrophoretic mobility shift assay, a 243-amino-acid fragment of Cdc13p (amino acids 451-693) was sufficient to bind single-stranded TG(1-3) with specificity similar to that of the native protein. Consistent with the in vitro observation, in vivo one-hybrid analysis also indicated that this region of Cdc13p was sufficient to localize itself to telomeres. However, the telomere-binding region of Cdc13p (amino acids 451-693) was not capable of complementing the growth defects of cdc13 mutants. Instead, a region comprising the Stn1p-interacting and telomere-binding region of Cdc13p (amino acids 252-924) complemented the growth defects of cdc13 mutants. These results suggest that binding to telomeres by Cdc13p is not sufficient to account for the cell viability, interaction with Stn1p is also required. Taken together, we have defined the telomere-binding domain of Cdc13p and showed that both binding to telomeres and Stn1p by Cdc13p are required to maintain cell growth.

Recovery of low-temperature stressed E. coli O157:H7 and its susceptibility to crystal violet, bile salt, sodium chloride and ethanol

This study was conducted to investigate the alteration of some characteristics of E. coli O157:H7 subjected to various periods of storage at -5, -18 and -28 degrees C. Results revealed that the low-temperature treatments increased the susceptibility of E. coli O157:H7 to crystal violet, bile salt, sodium chloride and ethanol. In general, the susceptibility of E. coli O157:H7 subjected to storage at -18 degrees C increased most significantly. The susceptibility of E. coli O157:H7 to the tested agents increased as the period of low-temperature storage extended, regardless of storage temperature. Among the various nitrogen and carbon sources tested, tryptone and soytone were the most effective nitrogen sources, while glucose and maltose were the most effective carbon sources for the growth of the low-temperature stressed cells. When growing the stressed E. coli O157:H7 in media containing the same nitrogen source or carbon source, their lag period increased as the time of frozen storage increased. It was also noted that in general, the recovery of the low-temperature stressed E. coli O157:H7 was highest on tryptic soy agar followed by Modified eosin methylene blue agar, while recovery on MaConkey sorbitol agar and Modified MaConkey sorbitol agar was lowest.

Development and validation of a pedestrian lower limb non-linear 3-d finite element model

Lower limb injury is becoming an increasingly important concern in vehicle safety for both occupants and pedestrians. To enable vehicle manufacturers to better understand the biomechanical effects of design changes, it is deemed beneficial to employ a biomechanically fidelic finite element model of the human lower limb. The model developed in this study includes long bones (tibia, fibula, femur) and flat bone (patella) as deformable bodies. The pelvis and foot bones are modeled as rigid bodies connected to the femur and tibia/fibula via rotational spring-dashpots. The knee is defined by scanned bone surface geometry and is surrounded by the menisci, major ligaments, and patellar tendon. Finite elements used to model include 6- and 8-node solids for cartilage, menisci, surrounding muscles, and cancellous bone; 3- and 4-node shells for skin and cortical bone; and nonlinear spring-dashpots for ligaments. Anatomical, physiological, and material properties data are from the literature while the bone surface geometry was scanned by a commercial source. Validation against published cadaver test results consisted of tibia and femur 3-point bending (lateralmedial and anterior-posterior) and whole limb lateral knee shear. Validation was performed under both static and dynamic loading conditions, until bone failure or ligament rupture. Additional dynamic validation with the lower limb in a seated orientation has not been completed, limiting current applications to the pedestrian impact condition. The validated models were employed to examine the effect of axial compressive force (the physiological condition) on tibia and femur lateral-medial and anterior-posterior bending under static conditions.

Determination of amphetamine and methamphetamine in serum via headspace derivatization solid-phase microextraction-gas chromatography-mass spectrometry

This study evaluates solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) to determine trace levels of amphetamine and methamphetamine in serum. Headspace post-derivatization in a laboratory-made design with heptafluorobutyric anhydride vapor following SPME was compared with that without derivatization SPME. The SPME experimental procedures to extract amphetamine and methamphetamine in serum were optimized with a relatively non-polar poly(dimethylsiloxane) coated fiber at pH 9.5, extraction time for 40 min and desorption at 260 degrees C for 2 min. Experimental results indicate that the concentration of the serum matrix diluted to a quarter of original (1:3) ratio by using one volume of buffer solution of boric acid mixed with sodium hydroxide and two volumes of water improves the extraction efficiency. Headspace derivatization following SPME was performed by using 6 microl 20% (v/v) heptafluorobutyric anhydride ethyl acetate solution at an oil bath temperature of 270 degrees C for 10 s. The precision was below 7% for analysis for without derivatization and below 17% for headspace derivatization. Detection limits were obtained at the ng/l level, one order better obtained in headspace derivatization than those achieved without derivatization. The feasibility of applying the methods to determine amphetamine and methamphetamine in real samples was examined by analyzing serum samples from methamphetamine abused suspects. Concentrations of the amphetamine and methamphetamine ranged from 6.0 microg/l (amphetamine) to 77 microg/l (methamphetamine) in serum.

Cloning and expression of ZAK, a mixed lineage kinase-like protein containing a leucine-zipper and a sterile-alpha motif

A novel mixed lineage kinase-like protein ZAK, containing a leucine-zipper (LZ) and a sterile-alpha motif (SAM), was cloned. This cDNA has 2456 bp and encodes a protein of 800 amino acids that contains a kinase catalytic domain, a leucine-zipper and a SAM. The molecular weight of this protein is 91kDa. Northern blot analysis revealed that the expression of this ZAK gene is found in various parts of human tissues. We also found that ZAK proteins might form homodimers or oligomers in mammalian cells. MLKs have been proposed to function as mitogen-activated protein kinase kinase kinase in pathways leading to MAPK cascade. The expression of ZAK in mammalian cells specifically leads to the activation of the JNK/SAPK pathway as well as the activation of transcription factor, NF-kappaB. Overexpression of the ZAK gene induces the apoptosis of a hepatoma cell line.

Tyr115, gln165 and trp209 contribute to the 1, 2-epoxy-3-(p-nitrophenoxy)propane-conjugating activity of glutathione S-transferase cGSTM1-1

We investigated the epoxidase activity of a class mu glutathione S-transferase (cGSTM1-1), using 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP) as substrate. Trp209 on the C-terminal tail, Arg107 on the alpha4 helix, Asp161 and Gln165 on the alpha6 helix of cGSTM1-1 were selected for mutagenesis and kinetic studies. A hydrophobic side-chain at residue 209 is needed for the epoxidase activity of cGSTM1-1. Replacing Trp209 with histidine, isoleucine or proline resulted in a fivefold to 28-fold decrease in the k(cat)(app) of the enzyme, while a modest 25 % decrease in the k(cat)(app) was observed for the W209F mutant. The rGSTM1-1 enzyme has serine at the correponding position. The k(cat)(app) of the S209W mutant is 2. 5-fold higher than that of the wild-type rGSTM1-1. A charged residue is needed at position 107 of cGSTM1-1. The K(m)(app)(GSH) of the R107L mutant is 38-fold lower than that of the wild-type enzyme. On the contrary, the R107E mutant has a K(m)(app)(GSH) and a k(cat)(app) that are 11-fold and 35 % lower than those of the wild-type cGSTM1-1. The substitutions of Gln165 with Glu or Leu have minimal effect on the affinity of the mutants towards GSH or EPNP. However, a discernible reduction in k(cat)(app) was observed. Asp161 is involved in maintaining the structural integrity of the enzyme. The K(m)(app)(GSH) of the D161L mutant is 616-fold higher than that of the wild-type enzyme. In the hydrogen/deuterium exchange experiments, this mutant has the highest level of deuteration among all the proteins tested. We also elucidated the structure of cGSTM1-1 co-crystallized with the glutathionyl-conjugated 1, 2-epoxy-3-(p-nitrophenoxy)propane (EPNP) at 2.8 A resolution. The product found in the active site was 1-hydroxy-2-(S-glutathionyl)-3-(p-nitrophenoxy)propane, instead of the conventional 2-hydroxy isomer. The EPNP moiety orients towards Arg107 and Gln165 in dimer AB, and protrudes into a hydrophobic region formed by the loop connecting beta1 and alpha1 and part of the C-terminal tail in dimer CD. The phenoxyl ring forms strong ring stacking with the Trp209 side-chain in dimer CD. We hypothesize that these two conformations represent the EPNP moiety close to the initial and final stages of the reaction mechanism, respectively.

The crystal structure of phosphoglucose isomerase/autocrine motility factor/neuroleukin complexed with its carbohydrate phosphate inhibitors suggests its substrate/receptor recognition

Phosphoglucose isomerase catalyzes the reversible isomerization of glucose 6-phosphate to fructose 6-phosphate. In addition, phosphoglucose isomerase has been shown to have functions equivalent to neuroleukin, autocrine motility factor, and maturation factor. Here we present the crystal structures of phosphoglucose isomerase complexed with 5-phospho-D-arabinonate and N-bromoacetylethanolamine phosphate at 2.5- and 2.3-A resolution, respectively. The inhibitors bind to a region within the domains' interface and interact with a histidine residue (His(306)) from the other subunit. We also demonstrated that the inhibitors not only affect the enzymatic activity of phosphoglucose isomerase, but can also inhibit the autocrine motility factor-induced cell motility of CT-26 mouse colon tumor cells. These results indicate that the substrate and the receptor binding sites of phosphoglucose isomerase and autocrine motility factor are located within close proximity to each other. Based on these two complex structures, together with biological and biochemical results, we propose a possible isomerization mechanism for phosphoglucose isomerase.

Growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes in egg products held at different temperatures

Growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes in steamed eggs and scrambled eggs held at different temperatures (5, 18, 22, 37, 55, and 60 degrees C) were investigated in the present study. Among the holding temperatures tested, both pathogens multiplied best at 37 degrees C followed by 22, 18, and 5 degrees C. In general, E. coli O157:H7 grew better in the egg products than L. monocytogenes did at all the storage temperatures tested except at 5 degrees C. E. coli O157:H7 did not grow in steamed eggs and scrambled eggs held at 5 degrees C. L. monocytogenes showed a slight population increase of approximately 0.6 to 0.9 log CFU/g in these egg products at the end of the 36-h storage period at 5 degrees C. The population of both pathogens detected in the egg products was affected by the initial population, holding temperature, and length of the holding period. It was also noted that L. monocytogenes was more susceptible than E. coli O157:H7 in steamed eggs held at 60 degrees C. After holding at 60 degrees C for 1 h, no detectable viable cells of L. monocytogenes with a population reduction of 5.4 log CFU/g was observed in steamed eggs, whereas a lower population reduction of only approximately 0.5 log CFU/ml was noted for E. coli O157:H7.

Capillary zone electrophoresis for the determination of atovaquone in serum

A rapid and simple capillary zone electrophoresis (CZE) method has been developed for the determination of atovaquone in serum. The drug was extracted from equine serum-chloroform (1:3, v/v) at greater than 80% recovery and assayed in buffer containing 25 mM sodium borate (pH 9.1) and 25% acetonitrile. A 100 microm I.D. fused-silica capillary was used and the detection was by UV-diode array at 254 nm; the migration time was approximately 8 min. Intra- and inter-assay variabilities were less than 7.8% and 5.8%, respectively, and the accuracy of the assay (expressed as % bias) ranged from 4.5 to -5.2%. The working assay range was from 2 to 100 microg/ml. This sensitivity could be increased by concentrating during the extraction procedure. Replacement of acetonitrile with 75 mM surfactant 3-(dimethyldodecylammonio)propanesulfonate gave similar sensitivity and provided an additional option to facilitate the separation of atovaquone on multiple-drug samples.

Growth of bifidobacteria in soymilk and their survival in the fermented soymilk drink during storage

Growth of Bifidobacterium infantis CCRC 14633 and B. longum B6, in soymilk was investigated in the present study. It was found that soymilk could support the growth of both organisms tested. B. infantis grew better than B. longum in soymilk. Supplementation of bifitose (isomaltooligosccharie), glucose, lactose or galactose to soymilk increased the growth of B. infantis and B. longum as determined after 48 h of fermentation. On the other hand, addition of yeast extract, peptone, tryptone, casitone or N-Z-Case plus to soymilk enabled B. infantis to reach its maximum population in a shorter cultivation time of 24 h. Acid production by B. longum and B. infantis in soymilk was mainly non-growth associated, while in the yeast extract-supplemented soymilk, acid produced by B. infantis was found to be growth-associated. Populations of B. longum reduced more than did B. infantis in the prepared fermented soymilk drink during storage period. Viable population of both test organisms reduced less in the fermented drink held at 5 degrees C than at 25 degrees C. After a 10-day storage at 5 degrees C, viable B. infantis and B. longum reduced by 0.44 and 3.18 log CFU/ml, respectively, in the fermented drink. Addition of sucrose to the fermented drink resulted in an increased reduction of viable bifidobacteria during the storage period. This phenomenon was most prominent with B. infantis in the fermented drink held at 25 degrees C.

The role of free to total prostate-specific antigen ratio for prostate cancer in screening patients with total serum levels between 4 and 20 ng/ml

BACKGROUND

We retrospectively tried to determine if the free to total prostate-specific antigen (f/t PSA) ratio could improve the specificity of PSA in prostate cancer screening of patients with total serum levels between 4 and 20 ng/ml.

METHODS

Two hundred ninety-five patients with serum PSA levels from 4 to 20 ng/ml had undergone sextant prostate needle biopsy. Each patient had no prior history of prostate cancer, acute urine retention, or prostatitis. Prebiopsy free PSA values were measured in 155 patients. Total PSA levels were determined with the AxSYM enzyme-linked immunosorbent assay. Free PSA levels were measured with the AxSYM microparticle enzyme immunoassay.

RESULTS

Mean f/t PSA ratios were 0.114+/-0.004 in men of the cancer group and 0.161+/-0.008 in men of the benign group (p<0.002). Based on the analysis of sensitivity and specificity in relation to f/t PSA ratios, use of the 18% cutoff point could detect 89% of cancer cases, and at the same time could avoid 35% of unnecessary prostate biopsies. The areas under the receiver-of-characteristic curve for f/t PSA ratio and total PSA were 0.649 and 0.545, respectively.

CONCLUSION

Serum f/t PSA ratios were significantly lower in patients with prostate cancer than in patients with benign disease. The determination of an appropriate f/t PSA ratio should be based on the generated data such as that demonstrated in this study in order to improve diagnostic accuracy and specificity for patients with equivocal PSA values and to avoid conducting unnecessary prostate biopsies.

Production and molar yield of 2-phenylethanol by Pichia fermentans L-5 as affected by some medium components

In this study, the effects of carbon sources and various levels of sucrose (0-30%) yeast extract (0-1.25%) and phenylalanine (0-0.2%) on the production of 2-phenylethanol by Pichia fermentans L-5 were investigated. Results revealed that among the 11 carbon sources tested, glycerol and sucrose were suitable carbon sources for P. fermentans L-5 resulting in production of higher amounts of 2-phenylethanol. In the medium that contained 18% sucrose, P. fermentans L-5 produced the highest amount of 2-phenylethanol, 283.4 mg/l with a molar yield of 0.77, was noted among the various levels of sucrose tested. Increasing the amount of phenylalanine added to the culture medium to 1.0% resulted in increased production of phenylethanol. Enhanced production of 2-phenylethanol, 453.1 mg/l by P. fermentans L-5 with a molar yield of 0.71 for phenylethanol was obtained in the medium containing 18% sucrose, 0.25% yeast extract and 0.1% phenylalanine after 16 h of fermentation.