Impact of Mitochondrial A3243G Heteroplasmy on Mitochondrial Bioenergetics and Dynamics of Directly Reprogrammed MELAS Neurons

The MELAS syndrome primarily affecting the CNS is mainly caused by the m.A3243G mutation. The heteroplasmy in different tissues affects the phenotypic spectrum, yet the impact of various levels of m.A3243G heteroplasmy on CNS remains elusive due to the lack of a proper neuronal model harboring m.A3243G mutation. We generated induced neurons (iNs) through the direct reprogramming of MELAS patients, with derived fibroblasts harboring high (>95%), intermediate (68%), and low (20%) m.A3243G mutation. iNs demonstrated neuronal morphology with neurite outgrowth, branching, and dendritic spines. The heteroplasmy and deficiency of respiratory chain complexes were retained in MELAS iNs. High heteroplasmy elicited the elevation in ROS levels and the disruption of mitochondrial membrane potential. Furthermore, high and intermediate heteroplasmy led to the impairment of mitochondrial bioenergetics and a change in mitochondrial dynamics toward the fission and fragmentation of mitochondria, with a reduction in mitochondrial networks. Moreover, iNs derived from aged individuals manifested with mitochondrial fission. These results help us in understanding the impact of various heteroplasmic levels on mitochondrial bioenergetics and mitochondrial dynamics in neurons as the underlying pathomechanism of neurological manifestations of MELAS syndrome. Furthermore, these findings provide targets for further pharmacological approaches of mitochondrial diseases and validate iNs as a reliable platform for studies in neuronal aspects of aging, neurodegenerative disorders, and mitochondrial diseases.

Regulation of Expression of Sterol Regulatory Element-binding Protein 1 in Thyroid Cancer Cells

BACKGROUND/AIM

Expression of sterol regulatory element-binding protein 1 (SREBP1) is upregulated in thyroid cancer and associated with shorter disease-specific survival. The molecular regulatory mechanisms governing SREBP1 over-expression in thyroid cancer are still unclear.

MATERIALS AND METHODS

Thyroid cancer cell lines BHT-101 (with the BRAF V600E mutation) and FTC-131 (wild-type for BRAF) were treated with specific inhibitors. The expression of SREBP1 was determined at the mRNA level using quantitative real-time PCR and at the protein level using immunoblotting.

RESULTS

Lenvatinib and a MEK inhibitor, selumetinib, suppressed SREBP1 expression in BHT-101 but not FTC-133 cells. Olitigaltin, a galectin-3 inhibitor, decreased SREBP1 expression in a time- and dose-dependent manner in both cells. MK2206, an allosteric AKT inhibitor, did not change SREBP1 expression in either cell line.

CONCLUSION

The galectin-3 inhibitor attenuates SREBP1 expression in thyroid cancer cells, likely independent of AKT phosphorylation. Lenvatinib and selumetinib decreases SREBP1 expression in the BRAF-mutant cell line BHT-101.

Ethacridine Induces Apoptosis and Differentiation in Thyroid Cancer Cells In Vitro

BACKGROUND/AIM

Ethacridine is used as a topical antiseptic as well as for second-trimester abortion. Recent studies showed that ethacridine is an inhibitor of poly(ADP-ribose) glycohydrolase (PARG) and an activator of the transcriptional coactivator with PDZ-binding motif (TAZ). This study examined the effects of ethacridine on thyroid cancer cells.

MATERIALS AND METHODS

Thyroid cancer cell lines (FTC133 and SW1736) and thyroid follicular epithelial cells (Nthy-ori 3-1) were treated with ethacridine. Viability, clonogenicity, cell-cycle distribution, and apoptosis were evaluated. The expression of thyroid differentiation markers (TTF-1, PAX8, and NIS) was determined by real-time PCR.

RESULTS

Ethacridine suppressed cell growth and clonogenic ability of thyroid cancer cells in a time- and dose-dependent manner (p<0.001). No cell-cycle arrest was found, but ethacridine dose-dependently induced apoptosis of thyroid cancer cells (p<0.001). The PAX8 and NIS expressions were significantly increased in SW1736 (3.41-fold and 1.53-fold, respectively) and Nthy-ori 3-1 cells (2.73-fold and 4.12-fold, respectively).

CONCLUSION

Ethacridine elicits apoptotic cell death in thyroid cancer cells and promotes differentiation in a subset of thyroid follicular cells.

Characterization and Mechanism for the Protection of Photolytic Decomposition of N-Halamine Siloxane Coatings by Titanium Dioxide

N-Halamine antibacterial materials have superior inactivation activities due to oxidative chlorine species. However, N-Cl bonds and bonds between N-halamine and substrates often decompose rapidly under UV irradiation, leading to unrecoverable loss of antimicrobial activity. In this study, titanium dioxide was covalently bonded onto N-halamine siloxane poly[5,5-dimethyl-3-(3'-triethoxysilylpropyl)hydantoin] (PSPH) via a sol-gel process. Experimental testing of the chlorinated cotton fabrics treated with TiO2/PSPH demonstrated that the residual oxidative chlorine in cotton-TiO2/PSPH-Cl was still effective for inactivating bacteria after 50 washing cycles and under UV light irradiation for 24 h. Quantum mechanical calculations found that TiO2 improves the UV stability of the PSPH-Cl system by increasing the activation barrier of the C-Si scission reaction responsible for the loss of the biocidal hydantoin moiety. SEM, XPS and FTIR spectra were used to characterize the coated cotton samples. Cotton-TiO2/PSPH-Cl samples exhibited good antibacterial activity against Staphylococcus aureus (ATCC 6538) and Escherichia coli O157:H7 (ATCC 43895). The storage stability and washing stability of treated cotton fabrics were also investigated.

Development of an integrated digital hand grip dynamometer and norm of hand grip strength

This study designs and fabricates a novel integrated digital hand grip dynamometer and analyzes collected grip strength data. The dynamometer directly stores collected data in a computer, unlike those on the market that cannot directly store information. A strain gauge load cell is used as a force sensor. The dynamometer is designed to maximize ergonomics. Excitation voltage of the load cell is 5 V, and a 9 V battery supplies power to its circuit. The signal receiver is National Instruments (NI) data acquisition (DAQ) card that transmits signals to the computer. The operation system is designed using LabView. This study assesses the correlation between variables of collected data. The correlation coefficients for height, weight and palm length were 0.793, 0.609 and 0.715, respectively, indicating that variables were moderately to strongly correlate with grip strength.

Self-assembled antibacterial coating by N-halamine polyelectrolytes on a cellulose substrate

In this research, two N-halamine polymer precursors, a cationic homopolymer poly((3-acrylamidopropyl)trimethylammonium chloride) (CHP) and an anionic homopolymer poly(2-acrylamido-2-methylpropane sulfonic acid sodium salt) (AHP), have been successfully synthesized and coated onto cotton fabrics via a layer-by-layer (LbL) deposition technique. The coated cotton fabrics were characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The biocidal efficacies of uncoated and coated cotton fabrics were evaluated against Staphylococcus aureus and Escherichia coli. The chlorinated swatches (CHP-Cl and AHP-Cl) inactivated 100% S. aureus and 99.73% E. coli O157:H7 in 30 min. Over 51% of the chlorine is retained after the equivalent of 50 machine washes. A skin stimulation test showed that CHP-Cl and AHP-Cl compounds have no irritation to rabbit skin, and so these swatches might be utilized for biomedical applications in the future. As an easy and efficient way of coating fabrics, the LbL deposition technique can broaden the use of N-halamine biocides in other polar substances as antimicrobial functional coatings.

No evidence of association between human cytomegalovirus infection and papillary thyroid cancer

BACKGROUND

Human cytomegalovirus (CMV) has been detected in the thyroid gland and thyroid tumors. CMV infection may activate the mitogen-activated protein kinase pathway, of which aberrant activation is frequently associated with BRAF mutation in papillary thyroid cancer.

METHODS

A total of 45 paired tumorous and adjacent non-neoplastic tissue samples, including 5 follicular adenoma and 40 papillary thyroid cancer, were obtained during thyroidectomy. BRAF mutational status was determined using direct sequencing. The presence of CMV DNA was determined using conventional PCR and quantitative real-time PCR. CMV protein in the tissue samples were evaluated with Western blot analysis.

RESULTS

BRAF mutation was identified in the cancerous part of 31 (78%) papillary thyroid cancers. Papillary cancer with BRAF mutation was significantly associated with a larger tumor size (P = 0.045), extrathyroidal invasion (P = 0.012), lymph node metastasis (P = 0.008), and a higher TNM stage (P = 0.044). CMV DNA and protein were not detected in any studied samples.

CONCLUSIONS

Our results suggest no association between CMV infection and papillary thyroid cancer.

High sensitivity, low noise Mirnov coil array on Prairie View rotamak

An array of 32 Mirnov coils with novel features of high sensitivity and low noise has been installed on the outside chamber surface of Prairie View rotamak. This B(R)-oriented coil array has proven to be very reliable in the plasma driven by rotating magnetic field; it can resolve magnetic perturbation signals of 0.1 G. With this new diagnostic, the n = 1 tilt, radial shift, and kink modes are observed for the first time in rotamak plasmas.

Polymeric antimicrobial N-halamine epoxides

A new N-halamine copolymer has been prepared, characterized, and evaluated for antimicrobial efficacy, stability toward hydrolyses, and stability toward UVA degradation when covalently bound to cellulose fibers. A copolymer of 3-chloro-2-hydroxypropylmethacrylate and glycidyl methacrylate was coated onto cotton, and, after curing, was treated with an aqueous solution containing the potassium salt of 5,5-dimethylhydantoin to form a coating which became antimicrobial upon exposure to househod bleach (sodium hypochlorite). The coating inactivated S. aureus and E. coli O157:H7 within minutes of contact time and was quite stable toward washing and UVA photodegradation.

N-halamine copolymers for use in antimicrobial paints

A series of copolymers containing units of a novel hydantoinylacrylamide and the sodium salt of 2-(acrylamido)-2-methylpropanesulfonic acid have been synthesized. The homopolymer of the hydantoinylacrylamide compound was insoluble in water, while the copolymers with the sulfonic acid sodium salt were water-dispersible/soluble, with the solution becoming completely transparent when the feed ratio for the copolymer contained 7 parts of the hydantoin moiety to 3 parts of the sodium sulfonate moiety. The polymers were added into a commercial water-based latex paint, and upon drying, the painted surfaces treated with the water-miscible copolymers were rendered antimicrobial following chlorination with dilute household bleach. The chlorinated homopolymer failed to provide an antimicrobial property for the paint because of its tendency to isolate into aggregates in the paint, while the completely miscible copolymers were capable of 6-log inactivation of Staphylococcus aureus and Escherichia coli O157:H7 within 5 min of contact time.

N-halamine biocidal coatings via a layer-by-layer assembly technique

Two N-halamine copolymer precursors, poly(2,2,6,6-tetramethyl-4-piperidyl methacrylate-co-acrylic acid potassium salt) and poly(2,2,6,6-tetramethyl-4-piperidyl methacrylate-co-trimethyl-2-methacryloxyethylammonium chloride) have been synthesized and successfully coated onto cotton fabric via a layer-by-layer (LbL) assembly technique. A multilayer thin film was deposited onto the fiber surfaces by alternative exposure to polyelectrolyte solutions. The coating was rendered biocidal by a dilute household bleach treatment. The biocidal efficacies of tested swatches composed of treated fibers were evaluated against Staphylococcus aureus and Escherichia coli. It was determined that chlorinated samples inactivated both S. aureus and E. coli O157:H7 within 15 min of contact time, whereas the unchlorinated control samples did not exhibit significant biocidal activities. Stabilities of the coatings toward washing and ultraviolet light exposure have also been studied. It was found that the stability toward washing was superior, whereas the UVA light stability was moderate compared to previously studied N-halamine moieties. The layer-by-layer assembly technique can be used to attach N-halamine precursor polymers onto cellulose surfaces without using covalently bonding tethering groups which limit the structure designs. In addition, ionic precursors are very soluble in water, thus promising for biocidal coatings without the use of organic solvents.

Suppression of n=1 tilt instability by magnetic shaping coils in Rotamak plasmas

Measurements from the array of Mirnov magnetic coils provide the first evidence for n=1 tilt and radial shift instabilities in a 40 ms field-reversed configuration (FRC) driven by rotating magnetic field. External plasma-shaping magnetic coils are utilized to suppress the n=1 instability modes. It is demonstrated that by energizing the middle shaping coil with 250-500 A current, the tilt mode is completely suppressed when a doublet FRC with an internal figure-of-eight separatrix is formed.

Immune responses to foot-and-mouth disease virus in pig farms after the 1997 outbreak in Taiwan

This paper reports on a retrospective study of the antibody responses to structural and non-structural proteins of FMD virus O Taiwan 97 in six pig herds in Taiwan in the year after the 1997 Taiwanese FMD outbreak. All herds were vaccinated against FMD after the outbreak as part of the countrywide control program. Three of the herds had confirmed FMD infections (herds N, O and P) and three herds remained non-infected (herds K, L and M). The serum neutralizing antibody titers and the non-structural protein ELISA (NSP) antibody responses in sows and 1-month-old pigs in the infected herds were higher than in the non-infected herds, but over time a number of positive NSP reactors were detected. From the serological studies and the herd monitoring and investigations it was considered that the FMD NSP positive reactors may not have constituted a true reservoir of FMD virus infection especially in herds where susceptible pigs were no longer present post-exposure or post-vaccination. Pigs vaccinated with an unpurified FMD type O vaccines being used at that time also showed false positive responses for NSP antibodies.

Rapid and sensitive magnetoelastic biosensors for the detection of Salmonella typhimurium in a mixed microbial population

In this article, we report the results of an investigation into the performance of a wireless, magnetoelastic biosensor designed to selectively detect Salmonella typhimurium in a mixed microbial population. The Langmuir-Blodgett (LB) monolayer technique was employed for antibody (specific to Salmonella sp.) immobilization on rectangular shaped strip magnetoelastic sensors (2 x 0.4 x 0.015 mm). Bacterial binding to the antibody on the sensor surface changes the resonance parameters, and these changes were quantified as a shift in the sensor's resonance frequency. Response of the sensors to increasing concentrations (5 x 10(1) to 5 x 10(8) cfu/ml) of S. typhimurium in a mixture of extraneous foodborne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes) was studied. A detection limit of 5 x 10(3) cfu/ml and a sensitivity of 139 Hz/decade were observed for the 2 x 0.4 x 0.015 mm sensors. Binding kinetics studies have shown that the dissociation constant (K(d)) and the binding valencies for water samples spiked with S. typhimurium was 435 cfu/ml and 2.33 respectively. The presence of extraneous microorganisms in the mixture did not produce an appreciable change in the biosensor's dose response behavior.

A magnetoelastic resonance biosensor immobilized with polyclonal antibody for the detection of Salmonella typhimurium

Mass-sensitive, magnetoelastic resonance sensors have a characteristic resonant frequency that can be determined by monitoring the magnetic flux emitted by the sensor in response to an applied, time varying, magnetic field. This magnetostrictive platform has a unique advantage over conventional sensor platforms in that measurement is wireless and remote. A biosensor for the detection of Salmonella typhimurium was constructed by immobilizing a polyclonal antibody (the bio-molecular recognition element) onto the surface of a magnetostrictive platform. The biosensor was then exposed to solutions containing S. typhimurium bacteria. Binding between the antibody and antigen (bacteria) occurred and the additional mass of the bound bacteria caused a shift in the sensor's resonant frequency. Sensors with different physical dimensions were exposed to different concentrations of S. typhimurium ranging from 10(2) to 10(9)CFU/ml. Detection limits of 5x10(3) CFU/ml, 10(5) CFU/ml and 10(7) CFU/ml were obtained for sensors with the size of 2 mmx0.4 mmx15 microm, 5 mmx1 mmx15 microm and 25 mmx5 mmx15 microm, respectively. Good agreement between the measured number of bound bacterial cells (as measured by scanning electron microscopy (SEM)) and frequency shifts was obtained.

Synthesis and antimicrobial applications of 5,5′-ethylenebis[5-methyl-3-(3-triethoxysilylpropyl)hydantoin]

A novel, durable, long lasting, N-halamine siloxane monomer precursor, 5,5'-ethylenebis[5-methyl-3-(3-triethoxysilylpropyl)hydantoin] has been prepared and characterized by (1)H-NMR and FTIR for the purpose of functionalizing the surfaces of various materials. In this work, the precursor N-halamine moiety was attached by siloxane covalent bonding to surfaces of cotton fibers. Simulated laundering tests indicated that the chlorinated N-halamine structure could survive many repeated home launderings. The materials were rendered biocidal after exposure to oxidative halogen solutions, i.e. dilute household bleach. Once chlorinated, these materials were biocidal against Staphylococcus aureus and Escherichia coli. Upon loss of the halogen from either long-term use or consumption by the microbes on the surfaces, they could be simply recharged by further exposure to dilute bleach to regain biocidal activity.

Phylogenetic analysis of classical swine fever virus in Taiwan

Two envelope glycoprotein (Erns and E2) regions of the classical swine fever virus (CSFV) were amplified by RT-PCR and sequenced directly from 158 specimens collected between 1989 and 2003 in Taiwan. Phylogenetic analysis of the two regions revealed a similar tree topology and the Erns region provided better discrimination than the E2 region. One hundred and fifteen isolates out of the 158 isolates were clustered within subgroup 2.1 (further classified as 2.1a and 2.1b) and 2.2, which were considered to be likely of the introduced strains, whereas the remaining 43 isolates were clustered within subgroup 3.4 and were considered to be of the endemic strains. The subgroup 2.1a viruses were first detected in 1994 and predominated from 1995 onwards. However, subgroup 3.4 viruses were prevalent in the early years, not being isolated after 1996. We have observed a dramatic switch in genotype from subgroup 3.4 to 2.1a. The subgroup 2.1a isolates are closely related to the Paderborn and Lao isolates, whereas 2.1b isolates have a close relationship to the Chinese Guangxi isolates. The phylogenetic tree of 27 CSFV sequences based on the complete envelope glycoprotein gene (Erns-E2) displayed better resolution than that based on the complete open reading frame.

Cytokeratin-19 associated with apoptosis and chemosensitivity in human cervical cancer cells

Cytokeratins are one group of intermediate filament proteins responsible for the integrity of cell structure, and have been recently reported to play a role in conferring a drug resistance phenotype. MAb Cx-99 is a monoclonal antibody exhibiting the specificity toward its corresponding antigen which was recently identified as the cytokeratin-19 protein. In the present study, we found that the level of cytokeratin-19 in cervical cancer cells could be decreased by incubation of cancer cells with MAb Cx-99. The reduction of cytokeratin-19 level had a killing effect on cervical carcinoma SIHA and HeLa S3 cell lines. The DNA ladder pattern, convoluted nuclei and blebbing morphology were observed with these cells after exposure to MAb Cx-99 for 72 h, suggesting that the cytotoxic mechanism of reduced cytokeratin-19 was mediated by induction of apoptosis. Moreover, the MAb Cx-99 treatment could increase the cytotoxicities of cancer chemotherapeutic agents such as cisplatin and vinblastine to both cervical carcinoma cell lines. The LD80 values were at least 15-fold reduced when cancer cells were treated with cisplatin or vinblastine in the presence of MAb Cx-99. These results suggest that the functional role of cytokeratin-19 was associated with the apoptosis prevention and drug resistance of cervical cancer cells.

Cell cycle G2/M arrest and activation of cyclin-dependent kinases associated with low-dose paclitaxel-induced sub-G1 apoptosis

Paclitaxel is a potential anti-cancer agent for several malignancies including ovary, breast, and head and neck cancers. This study investigated the kinetics of paclitaxel-induced cell cycle perturbation in two human nasopharyngeal carcinoma (NPC) cell lines, NPC-TW01 and NPC-TW04. NPC cells treated with higher concentrations (0.1 or 1 micro M) of paclitaxel showed obvious G2/M arrest and then converted to a cell population with reduced DNA content, which was detected as a sub-G2 peak in the flow cytometric histographs. If a low concentration (5 nM) of paclitaxel was used instead, transient G2/M arrest was observed in NPC cells, which subsequently converted to a sub-G1 form during the treatment period. Internucleosomal fragmentation and chromatin condensation were detectable in these sub-G1 and sub-G2 cells, suggesting that persistent or transient G2/M arrest is a prerequisite step for apoptosis elicited by varying doses of paclitaxel. The levels of cyclins A, B1, D1, E, CDK 1 (CDC 2), CDK 2 and proliferating cell nuclear antigen (PCNA) were unchanged in NPC cells following treatment with any concentration of paclitaxel; however, apoptosis-related cyclin B1-associated CDC 2 kinase was highly activated by paclitaxel even at concentrations as low as 5 nM, which is consistent with the finding that low-dose paclitaxel is also able to induce apoptosis in NPC cells. Activation of cyclin B1-associated CDC 2 kinase seems to be an important G2/M event required for paclitaxel-induced apoptosis, and this activation of cyclin B1/CDC 2 kinase could be attributed to the increased activity of CDK 7 kinase.

Elevated cytokeratin-19 expression associated with apoptotic resistance and malignant progression of human cervical carcinoma

Cytokeratin-19 is an intermediate filament protein associated with the integrity of cell structure, and its elevated expression has been reported to correlate with the disease progression of oesophagus and lung cancers. In this study, we examined the level of cytokeratin-19 in five cervical cancer cell lines by immunobinding and Western blotting analyses. Compared with two control cell lines, FS-4 (foreskin cell line) and G9T (glioma cell line), all five cervical carcinoma cell lines (Caski, CC7T, ME180, HeLa and SIHA) showed higher cytokeratin-19 expression. By double-staining flow cytometry, expression of cytokeratin-19 in cervical cancer cells was suggested to be in a cell cycle-independent manner. Furthermore, we could specifically localize the SIHA cell-derived tumours in nude mice by injecting with cytokeratin-19-recognized radiolabelled MAb Cx-99 antibody, suggesting the possibility of using cytokeratin-19 as a marker of cervical carcinoma. A clinical investigation was therefore performed on 19 patients (11 patients with cervical carcinoma and eight patients with benign neoplasia). In the 11 patients having cervical carcinoma, all eight patients with advanced stages and one out of three patients with early stage diseases showed higher cytokeratin-19 protein contents than the other 10 patients with benign neoplasia. This suggested that elevation of cytokeratin-19 level was associated with cervical cancer staging. In addition, we have studied the biological significance of elevated cytokeratin-19 level in malignant cervical cancer. The apoptotic rate of cervical carcinoma cells in response to cisplatin was increased if their cellular cytokeratin-19 level was reduced by specific antibody MAb Cx-99. These results indicated that elevation of cytokeratin-19 expression could associate with the apoptotic resistance and malignant progression of cervical carcinoma.

Differential inducibilities of GFAP expression, cytostasis and apoptosis in primary cultures of human astrocytic tumours

Glial fibrillary acidic protein (GFAP) is an astrocytic lineage-specific intermediate filament protein, and its expression or non-expression is inversely correlated with the tumourigenecity of astrocytoma cells. To estimate the GFAP levels of astrocytes in intracranial tumour tissues, we established primary cultures from six astrocytic tumour specimens and used a double-staining flow cytometric method to detect the different levels of GFAP among these primary cultures. Although these primary cultures exhibited the same Matrigel invasiveness, their GFAP expression is inversely related to the rate of cell growth and the histologic grade of the original tumour. Phenylacetate, 12-O-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate, which are potent inducers of differentiation in various cancer cells, have been examined for their effects on these primary cultures. Cytostasis was more or less caused by these compounds in all six primary cultures, but induction of GFAP was observed only in the primary culture derived from a less malignant astrocytoma specimen having the highest intrinsic GFAP level. Interestingly, this primary culture, but not others, also exhibited increased HRG-alpha expression after phenylacetate or sodium butyrate treatment. Loss of the inducibility of differentiation-related gene expression could be one of the events involved in the malignant progression of astrocytomas. In addition, the chemotherapeutic agent BiCNU has a killing effect on all six primary culture cells, with LD50 less than 60 nM. The underlying mechanism was through the induction of apoptosis in these primary culture cells regardless of their varying malignancies of original tumours. However, unlike colon cancer and leukaemia cells, sodium butyrate could not induce apoptosis within 4 days in these astrocytic tumour cells, indicating that the cell context of different cell types indeed determined the ability of sodium butyrate to induce apoptosis.

Conjugate addition of arylsilanes to unsaturated carbonyl compounds catalyzed by rhodium in air and water

ArSiCl3 and Ar2SiCl2, believed to be unstable in aqueous media, reacted efficiently with alpha,beta-unsaturated ketones and esters in air and water (in the presence of sodium fluoride and a rhodium catalyst), giving good to excellent yields of the desired conjugate addition products.

Methimazole-induced pulmonary hemorrhage associated with antimyeloperoxidase-antineutrophil cytoplasmic antibody: a case report

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis has been recently recognized in Graves' disease patients treated with antithyroid drugs. We describe the case of an 18-year-old girl who developed antimyeloperoxidase ANCA (MPO-ANCA)-positive vasculitis manifesting as a skin lesion and hemoptysis with hypoxic respiratory failure after taking methimazole. An open lung biopsy was consistent with acute capillaritis. Both skin and sural nerve biopsy showed lymphocytic vasculitis. Administration of steroid and plasmapheresis produced a good clinical response.

Inappropriate use of antibiotics and the risk for delayed admission and masked diagnosis of infectious diseases: a lesson from Taiwan

BACKGROUND

Antibiotic resistance is a serious problem worldwide. It is particularly alarming in Taiwan and other countries of the Pacific Rim, where antimicrobial drugs are used excessively.

OBJECTIVE

To determine whether use of antimicrobial drugs before coming to an emergency department was associated with delayed admission or masked or missed diagnoses at a large general hospital in Taiwan.

METHODS

Antimicrobial activity in urine (AAU) was determined in all patients seen in the emergency department during a 3-month study. A physician, unaware of the results of the urine tests, reviewed the medical charts of patients who were admitted to the hospital to determine whether admission was delayed for at least 7 days or the diagnosis was masked or missed.

RESULTS

Of the 1182 patients, 444 were admitted to the hospital. In 220 patients (49.5%), AAU was detected. There was no significant difference in AAU between patients with or without an infectious disease (53.0% vs 46.3%, respectively; P =.41). For patients with infection, 34.8% of those with AAU had a delayed admission, compared with only 21.6% without AAU (relative risk [RR], 1.61; 95% confidence interval [CI], 1.03-2.52; P =.03). For patients without infection, 36.2% of those with AAU had a delayed admission compared with 31.1% without AAU (RR, 1.16; 95% CI, 0.81-1.68; P =.64). For patients with infection, 48.7% of those with AAU had a masked or missed diagnosis, compared with 25.5% without AAU (RR, 1.91; 95% CI, 1.30-2.80; P<.001). For patients without infection, 27.6% of those with AAU had a masked or missed diagnosis compared with 14.8% without AAU (RR, 1.87; 95% CI, 1.11-3.17; P =.02).

CONCLUSION

Use of antimicrobial drugs before coming to an emergency department was associated with a significantly increased risk for delayed and masked or missed diagnoses of infectious diseases and missed diagnosis of noninfectious diseases.

GL331 induces down-regulation of cyclin D1 expression via enhanced proteolysis and repressed transcription

GL331 is a novel podophyllotoxin-derived compound. In this study, GL331 induced human lung adenocarcinoma cell line CL1-5 growth arrest before death during the initial 24-h incubation period. We found that GL331 had no inhibitory effect on the expression of cyclins E, A, B1, CDK 4, and CDK 2; instead, its cell growth-inhibitory effect was partly attributable to an early down-regulation of cyclin D1 expression and in turn the reduction of retinoblastoma protein phosphorylation. GL331 enhanced the proteolysis of cyclin D1, and a proteasome inhibitor was able to block GL331-caused cyclin D1 reduction, suggesting that GL331-stimulated cyclin D1 degradation was through proteasomal processes. Additionally, GL331 reduced cellular cyclin D1 mRNA level down to 45% of control in 4 h and further to around 20% in 12 h. However, GL331 did not accelerate the disappearance of cyclin D1 mRNA under the condition of transcription blockage induced by actinomycin D. It was reported that a certain region in the 3'-untranslated region (UTR) of cyclin D1 mRNA mediated the mRNA degradation upon extracellular stresses. Herein, transient transfection studies demonstrated that the 3'-UTR insertion did not confer the susceptibility of luciferase reporter gene to the GL331 treatment. Together, these data suggested that GL331 did not decrease the stability of cyclin D1 mRNA. On the other hand, we found that GL331 specifically inhibited the cyclin D1 promoter-driven luciferase reporter activity. Western blot analyses showed that GL331 decreased the level of phosphorylated extracellular signal-regulated kinase (Erk), with no effect on p38 or c-Jun NH(2)-terminal kinase. Furthermore, GL331's inhibition of cyclin D1 promoter was attenuated by ectopic Erk-2 overexpression. These data suggested that GL331 inhibited cyclin D1 gene transcription via the Erk signaling pathway. In summary, we report that GL331 induced an early decline of cyclin D1 expression by dual mechanisms: 1) enhancement of protein turnover and 2) repression of Erk-mediated gene transcription.

Molecular characterization of foot-and-mouth disease virus isolated from ruminants in Taiwan in 1999-2000

In 1999, 10 sporadic outbreaks of cattle foot-and-mouth disease (FMD) occurred in Taiwan. By the time, infection was limited to the Chinese yellow cattle (a native species of beef cattle in Mainland China), which did not develop vesicular lesions under field conditions. Five viruses isolates obtained from individual farms were confirmed to be the serotype O FMD virus (O/Taiwan/1999). During January-February 2000, however, this virus has spread to dairy cattle and goat herds, causing severe mortality in goat kids and vesicular lesions in dairy cattle. Partial nucleotide sequence of the capsid coding gene 1D (VP1) was determined for the virus isolates obtained in this study. Phylogenetic analysis of the VP1 sequences indicated that the O/Taiwan/1999 viruses shared 95-97% similarities to the virus strains isolated from the Middle East and India. The species susceptibility of the O/Taiwan/1999 virus was experimentally studied in several species of susceptible animals, showing that the virus did cause generalized lesions in dairy cattle and pigs, however, it would not cause vesicular lesions on the Chinese yellow cattle and the adult goats. These studies suggested that the O/Taiwan/1999 virus was a novel FMD virus of Taiwan and it presented various levels of susceptibility in cattle species.

Humic acid induced growth retardation in a sertoli cell line, TM4

Humic acid (HA) is a fluorescent deep brown organic, polymeric compound composed of phenolic acid. Intraperitoneal injection of HA in rats induced testicular morphological changes including degeneration of the seminiferous tubule, reduction in the number of Sertoli cells and spermatogonia, and a loss of spermatids. It was suggested that Sertoli cells may be involved in the progression of testicular atrophy. In this study, we used a mouse Sertoli cell Line, TM4, to investigate the effect of HA on Sertoli cells and the mechanism of the testicular atrophy induced by HA. We found that the cell growth of TM4 cells were reduced in 1 to 4 days of HA exposure. FACScan analysis of the DNA content of HA-treated TM4 cells revealed that there was no sub-G1 peak, indicating that the TM4 cells did not commit to the programmed cell death. However, a large proportion of TM4 cells were arrested at the G1 phase. The percentage of TM4 cells at the G1 phase increased from 36% to 84% after HA treatment for 4 days. Western blot assay of HA-treated TM4 cells showed that the expression of cyclin D1 protein decreased while the expression of p27kiP1 protein increased. These results suggest that HA-induced testicular atrophy is linked in part to an inhibitory effect on the growth of Sertoli cells. This model may be useful in investigation of environmental agents inducing testicular atrophy.

Comparison of the BACTEC MGIT 960 and BACTEC 460TB systems for detection of mycobacteria in clinical specimens

The reliability of the Mycobacteria Growth Indicator Tube (MGIT) 960 system for rapid detection of mycobacteria in clinical specimens was evaluated and compared to the radiometric method (BACTEC 460TB) and to mycobacterial culture on Lowenstein-Jensen (LJ) medium. Clinical specimens (n = 590) were tested without selection. A total of 121 (20.5%) isolates of mycobacteria were recovered; 98 (81.0%) of them were recovered with the BACTEC 460TB system, 86 (71.1%) were recovered with the BACTEC MGIT 960 system, and 55 (45.5%) were recovered with LJ medium (MGIT 960 versus BACTEC 640TB, p >0.05; MGIT 960 or BACTEC 460TB versus LJ, p <0.001). The mean time to detection (TTD) was 18 da for BACTEC 460 TB, and 13 da for BACTEC MGIT 960. The mean time to detection in each system, based upon data where both systems were culture positive, was significantly different (16.6 da for BACTEC 460TB and 13 da for BACTEC MGIT 960, p<0.001). The contamination rate of the BACTEC MGIT 960 system was 13.2%, which was intermediate between the BACTEC 460TB system (11.7%) and the LJ medium (14.7%). These data indicate that the fully automated MGIT 960 system is an accurate, non-radiometric alternative to the BACTEC 460TB method for rapid detection of mycobacteria in a clinical setting.

Novel synthesis of alpha-amino acids via catalysis in air and water

[reaction: see text] A new method was developed for the synthesis of natural and unnatural amino acid derivatives via carbon-carbon bond formation in air and water and at ambient temperature.

A novel topoisomerase II poison GL331 preferentially induces DNA cleavage at (C/G)T sites and can cause telomere DNA damage

PURPOSE

Topoisomerase II (Topo II) preferentially cuts DNA at alternating purine-pyrimidine repeats. Different Topo II poisons may affect Topo II to produce distinct drug-specific DNA cleavage patterns. GL331 is a new podophyllotoxin derivative exhibiting potent Topo II-poisoning activity. Therefore, the sequence selectivity of GL331-induced DNA cleavage was determined.

METHODS

Human gastric adenocarcinoma SC-M1 cells were treated with GL331, and the resultant DNA fragments were isolated by SDS-K+ precipitation. These DNA fragments were further cloned and sequenced to exhibit GL331-induced DNA cleavage sites. In addition, the telomere damage was detected by Southern blot analyses using a (TTAGGG)4 probe. GL331's effect on telomerase was examined using the TRAP assay.

RESULTS

The selective sequences of GL331-induced DNA cleavage were analyzed. The first nucleotide 3'-terminal to the cleavage sites was preferentially C or G and followed by the second nucleotide T. More than 50% of GL331-induced DNA cleavage fragments exhibited AT-rich sequences in the first 20 nucleotides. In addition, the telomeric damage was observed both from GL331-treated SC-M1 cells and in vitro incubation of genomic DNA with GL331 and purified human Topo II. Although GL331 treatment reduced cellular telomerase activity, in vitro reaction data suggested that GL331 was not a telomerase inhibitor.

CONCLUSION

GL331 preferentially induced Topo II-mediated DNA cleavage at (C/G)T sites. Because the telomeric repeat sequence contains GL331's GT preference site, the telomere was identified as one of the targets of GL331-induced DNA damage.

New strategies in the treatment of acute myelogenous leukemia (AML): in vitro culture of aml cells--the present use in experimental studies and the possible importance for future therapeutic approaches

In vitro studies of cultured native acute myelogenous leukemia (AML) blasts and cell lines have contributed significantly to our present knowledge about the pathogenesis of AML. In the present article we review different techniques for preparation and in vitro culture of AML blasts. Well-characterized serum-free in vitro conditions can now be used in experimental studies of AML, and this makes comparisons between different studies easier. We also describe assays for characterization of AML progenitor subsets (i.e., suspension cultures, colony assays, long-term in vitro culture, xenotransplantation in immunocompromised mice), and we discuss the possible use of AML cell lines as experimental models in AML. Furthermore, clinical studies suggest that the in vitro growth characteristics of AML blasts assayed by short-term culture of the total native populations can be used as a predictor of prognosis after intensive chemotherapy. These in vitro assays may therefore be used for more accurate identification of prognostic parameters and thereby form a basis for the development of simplified laboratory techniques suitable for routine evaluation of patients undergoing risk-adapted therapy. However, it will be equally important to further evaluate the clinical relevance of assays for primitive AML progenitors, and to develop simplified methods that can be used to characterize these progenitor subsets in the routine clinical evaluation.

Evaluation of GL331 in combination with paclitaxel: GL331's interference with paclitaxel-induced cell cycle perturbation and apoptosis

Combination of selecting agents that act on different cellular mechanisms is a common strategy in cancer chemotherapy. GL331 is a new potent topoisomerase II (Topo II) poison; distinctly, paclitaxel is a microtubule-interfering cancer chemotherapeutic agent. In this study, we intended to evaluate the efficacy of combining GL331 with paclitaxel in cell killing and apoptotic induction in nasopharyngeal carcinoma NPC-TW01 cells. By MTT and internucleosomal DNA cleavage assays, we found that pretreatment or simultaneous treatment of NPC-TW01 cells with GL331 could significantly interfere with paclitaxel's cell killing and apoptosis-inducing activity. When the administration schedule was reversed, the cytotoxicity of GL331 was attenuated by paclitaxel pretreatment. The anti-cancer activity produced by combining GL331 with paclitaxel was obviously lower than the addition of the activities of two individual agents. NPC-TW01 cells were treated with GL331 and 3H-labeled paclitaxel simultaneously or with GL331 before 3H-labeled paclitaxel. In both conditions, GL331 did not reduce the [3H]paclitaxel level in the cells, suggesting that GL331's interference with paclitaxel's cell-killing and apoptosis-inducing efficacy did not result from any inhibition of cellular uptake or retention of paclitaxel. In addition, we found that GL331-induced perturbation of cell cycle progression dramatically over-rode the patterns of mitotic arrest induced by paclitaxel, and the mechanism could be the inhibition of cyclin B1/CDC2 kinase and MAD2 checkprotein activities.

Delayed endolymphatic hydrops: study and review of clinical implications and surgical treatment

Delayed endolymphatic hydrops (DEH) differs from Ménière's disease in that it occurs in pre-existing ear pathology in patients who have a profound unilateral or total deafness that was caused by infection, trauma, or unknown causes during childhood or adulthood. We performed a retrospective review of 160 patients with ipsilateral, contralateral, or bilateral DEH. Eighty-seven patients who did not respond to medical therapy underwent surgical treatment. Our findings indicate that the more conservative surgical procedures--endolymphatic sac surgery, cochleosacculotomy, and streptomycin perfusion--are all as effective as and less destructive than labyrinthectomy for controlling vertigo. The clinical results of this study would seem to support the observations of others that DEH and Ménière's disease are related disorders caused predominantly by cases of viral labyrinthitis with unknown etiology.

The relation of serum leptin to body mass index and to serum cortisol in men with spinal cord injury

OBJECTIVE

To investigate the relations among serum leptin, body mass index (BMI), and various hormone levels in men with spinal cord injury (SCI).

DESIGN

Cross-sectional.

SETTING

University hospital that is a tertiary referral center.

PARTICIPANTS

Forty-seven men with traumatic neurologically complete SCI and 47 age- and BMI-matched male controls.

MAIN OUTCOME MEASURES

Baseline levels of various hormones were measured in subjects with SCI. Serum leptin and cortisol levels and BMI were measured in both groups.

RESULTS

Serum leptin was significantly higher in the group with SCI than in the control group. A linear relation was found between serum leptin and BMI in both groups separately. A polynomial relation was found between serum leptin level and BMI in the group with SCI. A "J" phenomenon is noted at the lowest BMI. Serum cortisol correlated significantly with serum leptin level in the group with SCI.

CONCLUSION

Sympathetic denervation, peripheral nerve palsy, recurrent infections, and possible central neurotransmitter alterations after SCI may contribute to the elevation of serum leptin level in men with SCI.

Decreased autonomic nervous system activity as assessed by heart rate variability in patients with chronic tetraplegia

OBJECTIVES

To assess the alterations of autonomic nervous functions and sympathovagal balance of the subjects with spinal cord injuries (SCIs) in different levels by heart rate variability analysis.

DESIGN

Prospective, observational study.

SETTING

All participants were recruited from the outpatient clinic from National Taiwan University Hospital, which is a tertiary referral center.

PARTICIPANTS

Thirty-one patients with traumatic chronic complete SCI (more than 6 months): 14 with paraplegia (Group A), and 17 with tetraplegia (Group B).

MAIN OUTCOME MEASURES

Heart rate variability assessed by 24-hour Holter monitoring.

RESULTS

Two patients in Group A and 1 in Group B were excluded from final data analysis because of poor recording data. Two time domain variables, the standard deviation (SD) of all normal RR intervals (SDNN) and the mean of the SDs of all normal RR intervals for all 5-minute intervals (SDNNi), over 24 hours were decreased in Group B. All time domain variables, SDNN, SDNNi, root mean square of the successive normal RR interval difference (rMSSD), and the percentage of RR intervals differing >50msec from the preceding one (pNN50), were decreased during the nighttime recordings (all p < .05) in Group B. The very-low-frequency, low-frequency (LF), and high-frequency (HF) components of the power spectrum of the RR intervals were also decreased in Group B (p < .05), irrespective of the daytime and nighttime recordings. The LF-to-HF ratio did not differ significantly in these two groups, indicating the maintained sympathovagal balance in the chronic SCI patients.

CONCLUSION

These findings suggested that the autonomic nervous system activity was depressed in the patients with chronic tetraplegia, but the autonomic nervous system still maintained homeostasis.

Molecular epidemiological studies on foot-and-mouth disease type O Taiwan viruses from the 1997 epidemic

Sequence diversity was assessed of the complete VP1 gene directly amplified from 49 clinical specimens during an explosive foot-and-mouth disease (FMD) outbreak in Taiwan. Type O Taiwan FMD viruses are genetically highly homogenous, as seen by the minute divergence of 0.2-0.9% revealed in 20 variants. The O/HCP-0314/TW/97 and O/TCP-022/TW/97 viral variants dominated FMD outbreaks and were prevalent in most affected pig-raising areas. Comparison of deduced amino acid sequences around the main neutralizable antigenic sites on the VP1 polypeptide showed no significant antigenic variation. However, the O/CHP-158/TW/97 variant had an alternative critical residue at position 43 in antigenic site 3, which may be due to selective pressure in the field. Two vaccine production strains (O1/Manisa/Turkey/69 and O1/Campos/Brazil/71) probably provide partial heterologous protection of swine against O Taiwan viruses. The type O Taiwan variants clustered in sublineage A1 of four main lineages in the phylogenetic tree. The O/Hong Kong/9/94 and O/1685/Moscow/Russia/95 viruses in sublineage A2 are closely related to the O Taiwan variants. The causative agent for the 1997 epidemic presumably originated from a single common source of type O FMD viruses prevalent in neighboring areas.

Activation of MAD 2 checkprotein and persistence of cyclin B1/CDC 2 activity associate with paclitaxel-induced apoptosis in human nasopharyngeal carcinoma cells

Paclitaxel (Taxol) is a microtubule-interfering agent that induced persistent and transient G2/M arrest before apoptosis in human nasopharyngeal carcinoma (NPC) cells at high and low concentrations, respectively. In this study, we intended to explore the underlying molecular events and found that cellular cyclin B1/CDC 2 kinase activity was increased and persisted for >6 h upon paclitaxel treatment both at high and low concentrations. Furthermore, activation of MAD 2 checkprotein could account for the loss of cyclin B1 ubiquitination and the persistence of cyclin B1/CDC 2 activation in the cases. To investigate the involvement of cyclin B1 and MAD 2 activation in paclitaxel-induced apoptosis, we introduced affinity-purified anti-cyclin B1 and MAD 2 antibodies into NPC cells by electroporation before the further paclitaxel treatment. The antibodies against cyclin B1 and MAD 2 indeed attenuated paclitaxel-induced cytotoxicity and DNA fragmentation. Our study suggests that activation of cyclin B1/CDC 2 and MAD 2 were the M-phase events required for paclitaxel-induced apoptosis in NPC cells. The dys-regulated cyclin B1/CDC 2 activation could enhance the prometaphase progression, but activation of MAD 2 rendered cells inable to exit from the metaphase. Under this circumstance, cells were probably going to "mitotic catastrophe" and ultimately, destined to apoptosis.

A cell adhesion protein from the crayfish Pacifastacus leniusculus, a serine proteinase homologue similar to Drosophila masquerade

A cDNA encoding a protein resembling masquerade, a serine proteinase homologue expressed during embryogenesis, larval, and pupal development in Drosophila melanogaster, was identified in hemocytes of the adult freshwater crayfish, Pacifastacus leniusculus. The crayfish protein is similar to Drosophila masquerade in the following aspects: (a) overall sequence of the serine proteinase domain, such as the position of three putative disulfide bridges, glycine in the place of the catalytic serine residue, and the presence of a substrate-lining pocket typical for trypsins; (b) the presence of several copies of a disulfide-knotted motif in the putative propeptide. This masquerade-like protein is cleaved into a 27-kDa fragment, which could be detected by immunoblot analysis using an affinity-purified antibody against a synthetic peptide in the C-terminal domain of the protein. The 27-kDa protein could be immunoaffinity-purified from hemocyte lysate supernatant and exhibited cell adhesion activity in vitro, indicating that the C-terminal domain of the crayfish masquerade-like protein mediates cell adhesion.

Repetitive graded ACTH stimulation test for adrenal insufficiency

ACTH stimulation is useful in assessing the hypothalamo-pituitary-adrenal axis. However, there is still some debate about the proper dose and interpretation. We designed a new protocol using repetitive graded ACTH stimulation. Thirty-two patients with the diagnosis of adrenal insufficiency (Al) were studied. After taking samples for baseline ACTH and cortisol, 1 microg fresh-prepared ACTH (Synacthen (1-24)) was injected intravenously, then 5, 50 and 100 microg at hourly interval. Cortisol responses were measured at 30, 60, 120, 180 and 240 min. The secondary Al group (26 subjects) had cortisol responses in between those of the control group (8 subjects) and the primary Al group (6 subjects). The minimal overlap between the secondary Al group and the control group occurred at a 30-min cortisol response after 1 microg ACTH stimulation, using 20 microg/dl as the cut-off level. There was only one exception which showed an episodic release at 30 min. There were 5, 10 and 9 patients with secondary Al who responded normally to 5, 50 and 100 microg ACTH stimulation, respectively. Maximal cortisol increments of the primary Al group were all below 4 microg/dl. Although there were 11 cases of secondary Al whose cortisol responses overlapped with those of primary Al, only two of them had a cortisol increment less than 4 microg/dl. Our new protocol combines the advantage of the low dose ACTH stimulation test, a sensitive method for detecting mild Al, and the ACTH infusion test, a longer test to mimic surgical stress.