X-ray microfabrication and measurement of a terahertz mode converter

Mode converters are critical for frequency-tunable terahertz gyrotrons. This study reports the development of a broadband TE(02) mode converter centered at 0.2 THz. An octafeed sidewall coupling structure was employed and the mode purity was analyzed. The converter was built using the technique of x-ray microfabrication. The x rays irradiated on the SU-8 resist and generated a template of very high thickness of 1.295 mm. Pulse electroplating technique was used to deposit copper on the structure along the template. The parts then went through precise machining and the residual resist was removed via high-flux radical etching. A computer-aided diagnostic system was introduced to measure the performance of the converter. Results suggest that the frequency response of resistivity should be taken into consideration for the devices in terahertz region.

Constructed wetland for water quality improvement: a case study from Taiwan

In Taiwan, more than 20% of the major rivers are mildly to heavily polluted by domestic, industrial, and agricultural wastewaters due to the low percentage of sewers connected to wastewater treatment plants. Thus, constructed or engineered wetlands have been adopted as the major alternatives to clean up polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems for the wastewater polishment to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before it is discharged into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks for organics and metals. In this study, water and sediment samples were collected from the major wetland basins in KRRBCW. The investigation results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g. total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g. Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O(2)/m(2) d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TN). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that a variation in microbial diversity in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradual disappearance of E. coli was also observed along the flow courses through natural attenuation mechanisms.

Preliminary identification of watershed management strategies for the Houjing river in Taiwan

The Houjing River watershed is one of the three major river watersheds in the Kaohsiung City, Taiwan. Based on the recent water quality analysis, the Houjing River is heavily polluted. Both point and non-point source (NPS) pollutants are the major causes of the poor water quality in the Houjing River. Investigation results demonstrate that the main point pollution sources included municipal, agricultural, and industrial wastewaters. In this study, land use identification in the Houjing River watershed was performed by integrating the skills of geographic information system (GIS) and global positioning system (GPS). Results show that the major land-use patterns in the upper catchment of the Houjing River watershed were farmlands, and land-use patterns in the mid to lower catchment were residential and industrial areas. An integrated watershed management model (IWMM) and Enhanced Stream Water Quality Model (QUAL2K) were applied for the hydrology and water quality modeling, watershed management, and carrying capacity calculation. Modeling results show that the calculated NH₃-N carrying capacity of the Houjing River was only 31 kg/day. Thus, more than 10,518 kg/day of NH₃-N needs to be reduced to meet the proposed water quality standard (0.3 mg/L). To improve the river water quality, the following remedial strategies have been developed to minimize the impacts of NPS and point source pollution on the river water quality: (1) application of BMPs [e.g. source (fertilizer) reduction, construction of grassy buffer zone, and land use management] for NPS pollution control; (2) application of river management scenarios (e.g. construction of the intercepting and sewer systems) for point source pollution control; (3) institutional control (enforcement of the industrial wastewater discharge standards), and (4) application of on-site wastewater treatment systems for the polishment of treated wastewater for water reuse.

Using a constructed wetland for non-point source pollution control and river water quality purification: a case study in Taiwan

The Kaoping River Rail Bridge Constructed Wetland, which was commissioned in 2004, is one of the largest constructed wetlands in Taiwan. This multi-function wetland has been designed for the purposes of non-point source (NPS) pollutant removal, wastewater treatment, wildlife habitat, recreation, and education. The major influents of this wetland came from the local drainage trench containing domestic, agricultural, and industrial wastewaters, and effluents from the wastewater treatment plant of a paper mill. Based on the quarterly investigation results from 2007 to 2009, more than 96% of total coliforms (TC), 48% of biochemical oxygen demand (BOD), and 40% of nutrients (e.g. total nitrogen, total phosphorus) were removed via the constructed wetland system. Thus, the wetland system has a significant effect on water quality improvement and is capable of removing most of the pollutants from the local drainage system before they are discharged into the downgradient water body. Other accomplishments of this constructed wetland system include the following: providing more green areas along the riversides, offering more water assessable eco-ponds and eco-gardens for the public, and rehabilitating the natural ecosystem. The Kaoping River Rail Bridge Constructed Wetland has become one of the most successful multi-function constructed wetlands in Taiwan. The experience obtained from this study will be helpful in designing similar natural treatment systems for river water quality improvement and wastewater treatment.

Application of integrated GIS and multimedia modeling on NPS pollution evaluation

In Taiwan, nonpoint source (NPS) pollution is one of the major causes of the impairment of surface waters. I-Liao Creek, located in southern Taiwan, flows approximately 90 km and drains toward the Kaoping River. Field investigation results indicate that NPS pollution from agricultural activities is one of the main water pollution sources in the I-Liao Creek Basin. Assessing the potential of NPS pollution to assist in the planning of best management practice (BMP) is significant for improving pollution prevention and control in the I-Liao Creek Basin. In this study, land use identification in the I-Liao Creek Basin was performed by properly integrating the skills of geographic information system (GIS) and global positioning system (GPS). In this analysis, 35 types of land use patterns in the watershed area of the basin are classified with the aid of Erdas Imagine process system and ArcView GIS system. Results indicate that betel palm farms, orchard farms, and tea gardens dominate the farmland areas in the basin, and are scattered around on both sides of the river corridor. An integrated watershed management model (IWMM) was applied for simulating the water quality and evaluating NPS pollutant loads to the I-Liao Creek. The model was calibrated and verified with collected water quality and soil data, and was used to investigate potential NPS pollution management plans. Simulated results indicate that NPS pollution has significant contributions to the nutrient loads to the I-Liao Creek during the wet season. Results also reveal that NPS pollution plays an important role in the deterioration of downstream water quality and caused significant increase in nutrient loads into the basin's water bodies. Simulated results show that source control, land use management, and grassy buffer strip are applicable and feasible BMPs for NPS nutrient loads reduction. GIS system is an important method for land use identification and waste load estimation in the basin. Linking the information of land utilization with the NPS pollution simulation model may further provide essential information of potential NPS pollution for all subregions in the river basin. Results and experience obtained from this study will be helpful in designing the watershed management and NPS pollution control strategies for other similar river basins.

Two Taiwanese siblings with dyschromatosis universalis hereditaria

Two Taiwanese siblings presented with clinical and histological findings of dyschromatosis universalis hereditaria, which is an uncommon hereditary skin disease. A 26-year-old Taiwanese man had developed diffuse hyperpigmentation with hypopigmented spots over his whole body from the age of 4 years. His 34-year-old brother had also developed a similar skin pigmentary defect from about the same age. Histological examination of the hyperpigmented lesions found an increase in melanin in the basal layer, pigmentary incontinence, and some melanophages in the upper dermis but no increase in the number of melanocytes. The unique clinical, histological, and genetic features of this condition are outlined.

Malignancies associated with dermatomyositis and polymyositis in Taiwan: a nationwide population-based study

BACKGROUND

Previous studies showed that idiopathic inflammatory myopathies (IIM) carried an increased risk of cancers. However, no large-scale study of IIM has been conducted in the Chinese population.

OBJECTIVES

We sought to delineate the association of IIM and various cancer types from a nationwide database in Taiwan.

METHODS

We analysed the published national data from records of National Health Insurance claims. Cases of dermatomyositis (DM) and polymyositis (PM) from 2000 to 2005 and cancers registered in the catastrophic illness profile from 1997 to 2006 were collected. A nationally representative cohort of 1,000,000 enrollees was included for comparison.

RESULTS

In total, 136 patients (12.8%) among 1059 cases of DM and 46 persons (7.0%) among 661 cases of PM carried internal malignancies. Patients with DM tended to have cancers of nasopharynx, lung and breast. On the other hand, patients with PM tended to have breast, uterine cervix and lung cancers. Compared with the general population, DM gave a 10-fold increased risk for cancers, in which a 66-fold increased risk for nasopharyngeal carcinoma and a 31-fold increased risk for lung cancer were the two most significant. For patients with PM, a 6-fold increased risk for cancer was observed. Juvenile DM had a 16-fold increased risk for haematopoietic or lymphoid malignancy. Two thirds of comorbid malignancies were detected shortly after the diagnoses of IIM, within a mean of 1-2 years. Overall, younger patients with IIM carried the highest risk for malignancies, especially those in their twenties and thirties.

CONCLUSIONS

This is the first large-scale study to report the associated malignancies and the cancer risk of IIM in Taiwan.

Collective oblate rotation at high spins in neutron-rich 180Hf

We report on experimental evidence for collective oblate rotation becoming favored at high spins in a rigid, well-deformed, axially symmetric nucleus. Excited states established up to spin 20variant Planck's over 2pi in 180Hf are consistent with predictions that nucleon alignments would favor oblate over prolate shapes at high spins in neutron-rich Hf isotopes. The results highlight the influence of valence orbitals on the interplay between nucleon alignments and nuclear shapes and provide a rare example of independent particle dynamics in competing potential wells.

Epoetin alfa and darbepoetin alfa: effects on ventricular hypertrophy in patients with chronic kidney disease

BACKGROUND

Anemia is very common in chronic kidney disease (CKD) and is commonly treated with recombinant human erythropoietin. The aim of this study was to analyze the efficacy of epoetin alfa and darbepoetin alfa on left ventricular parameters in patients with CKD.

METHODS

Patients with CKD not yet dependent on dialysis were randomly assigned to treatment with epoetin alfa at weekly intervals (Epo group; baseline hemoglobin 8.5 +/- 0.8 mg/dL, creatinine clearance 10.0 +/- 2.0 ml/min per 1.73 m2) or darbepoetin alfa every 2 weeks (Dar group; baseline hemoglobin 8.2 +/- 0.8 mg/dL, creatinine clearance 10.8 +/- 2.4 ml/min per 1.73 m2). Patients not receiving erythropoietin served as a control group. Two-dimensional color Doppler echocardiography was performed at baseline and at 24 weeks to measure left ventricular mass index (LVMI) and ejection fraction.

RESULTS

Hemoglobin in the 2 treatment arms was corrected to 10.6 +/- 0.6 mg/dL and 10.7 +/- 0.5 mg/dL for Epo and Dar groups, respectively. The LVMI decreased significantly in both the Epo (-5.7 +/- 14.2 g/m2) and the Dar group (-5.6 +/- 15.8 g/m2) but increased in the control group (9.0 +/- 15.1 g/m2; p=0.02, between the Epo and control groups, and between the Dar and control groups). The ejection fraction was increased in both treatment groups (Epo group: 2.45% +/- 2.28%, Dar group: 1.64% +/- 2.95%) and decreased in controls (-1.15% +/- 3.69%) (p=0.004 among groups). The 2 treatment groups showed similar efficacy. The degree and the change of renal function did not differ among the 3 groups at end of study.

CONCLUSIONS

The 2 erythropoiesis-stimulating agents epoetin alfa and darbepoetin alfa, when given to patients with CKD in doses aimed at standard anemia correction are associated with a similar degree of LVMI reduction, in the absence of a concomitant enhancement of CKD progression.

Application of biofiltration system on AOC removal: column and field studies

The Cheng-Ching Lake Water Treatment Plant (CCLWTP) is the main supplier of domestic water for the Greater Kaohsiung area, the second largest metropolis in Taiwan. Biological activated carbon (BAC) filtration is one of the major treatment processes in CCLWTP. The objectives of this study were to evaluate the effectiveness of BAC filtration on water treatment in the studied advanced water treatment plant and its capability on pollutants [e.g., AOC (assimilable organic carbon), bromide, bromate, iron] removal. In this study, water samples from each treatment process of CCLWTP were collected and analyzed periodically to assess the variations in concentrations of AOC and other water quality indicators after each treatment unit. Moreover, the efficiency of biofiltration process using granular activated carbon (GAC) and anthracite as the fillers was also evaluated through a column experiment. Results show that the removal efficiencies for AOC, bromide, bromate, and iron are 86% 100%, 17%, and 30% after the BAC filter bed, respectively. This indicates that BAC filtration plays an important role in pollutant removal. Results also show that AOC concentrations in raw water and effluent of the CCLWTP are approximately 143 and 16 microg acetate-Cl(-1), respectively. This reveals that the treatment processes applied in CCLWTP is able to remove AOC effectively. Results of column study show that the AOC removal efficiencies in the GAC and anthracite columns are 60% and 17%, respectively. Microbial colonization on GAC and anthracite were detected via the observation of scanning electron microscopic images. The observed microorganisms included bacteria (rods, cocci, and filamentous bacteria), fungi, and protozoa. Results from this study provide us insight into the mechanisms of AOC removal by advanced water treatment processes. These findings would be helpful in designing a modified water treatment system for AOC removal and water quality improvement.

Interpopulation and intrapopulation maternal lineage genetics of the Lanyu pig (Sus scrofa) by analysis of mitochondrial cytochrome b and control region sequences

The Lanyu pig is an indigenous breed from the Lanyu Islet, which is southeast of Taiwan. Two herds of Lanyu pigs were introduced from the Lanyu Islet into Taiwan in 1975 and 1980. The current population of conserved Lanyu pigs consists of only 44 animals with unknown genetic lineage. The Lanyu pig possesses a distinct maternal genetic lineage remote from Asian and European pigs. The present study aimed to understand the phylogenetic relationship among conserved Lanyu, Asian, and European type pigs based on the cytochrome b coding gene, to ascertain the maternal lineage and genetic diversity within the conserved Lanyu pigs, and to address whether genetic introgression from exotic or Formosan wild pigs had occurred in the conserved Lanyu pigs. Entire mitochondrial genomes of both types of Lanyu pig comprised 2 ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes. Only 2 haplotypes of the mitochondrial DNA (mtDNA) control region and cytochrome b were identified in the conserved Lanyu pig herds. When maximum likelihood trees were constructed, the Type I Lanyu mitochondrial genes formed a unique clade with a large pairwise distance of both cytochrome b and the control region from Asian and European type breeds, Formosan wild pigs, and exotic breeds. Significant loss of genetic diversity of mtDNA within the conserved Lanyu pigs was demonstrated by low haplotype and nucleotide diversities, supported by Fu and Li's D* neutrality test (1.44055; P < 0.05). The mtDNA control region sequences of extant pigs in the Lanyu Islet, however, showed high haplotype and nucleotide diversity, and clustered with exotic pigs. These results indicate no maternal lineage mtD-NA gene introgression from Formosan wild pigs and introduced exotic pigs to conserved Type I Lanyu pigs, and a severe loss of heterozygosity of mtDNA in conserved Lanyu pigs. The remaining extant pigs on the Lanyu Islet have been introgressed with exotic breeds. Strategies for future conservation of native Lanyu pigs are now even more urgent and important.

The type I Lanyu pig has a maternal genetic lineage distinct from Asian and European pigs

The Lanyu pig is an indigenous breed from Lanyu Islet, located south-east of Taiwan, with phenotypic characteristics distinctive from other pig breeds in Asia and Europe. Based on geographic considerations, the Lanyu pig may have originated from mainland China, Austronesia or the Ryukyu Islands. In the present study, polymorphism of the mitochondrial DNA control region sequence was used to clarify phylogenetic relationships among two herds of Lanyu pigs imported before 1980 from Lanyu Islet into Taiwan and reared in isolation on two different farms. Two distinct mitochondrial control region haplotypes were found. The type I Lanyu sequence appeared independently as a unique clade different from Asian and European pig sequences, while the type II Lanyu sequence was clustered within the major Asian clade. The pairwise distances between the major Asian clade vs. the type I Lanyu and European clades were 0.01726 +/- 0.00275 and 0.01975 +/- 0.00212 changes per site respectively. Estimates of divergence time suggest that the type I Lanyu sequence split from the major Asian pig clade in prehistoric times. The type II Lanyu mtDNA shares a close genetic lineage with Japanese Satsuma and New Zealand Kune Kune mtDNA with pairwise distances of 0.00095 +/- 0.00000 and 0.00192 +/- 0.00000 respectively, indicating gene flow between Lanyu Islet, Japan and Oceania in recent times. Together these results indicate that the type I Lanyu pig has a genetic lineage separate from Asian-type pigs, while the type II Lanyu sequence may represent a more recent introgression of modern Asian pigs.

Observation of locomotor functional recovery in adult complete spinal rats with BWSTT using semiquantitative and qualitative methods

STUDY DESIGN

Experimental rat model of spinal cord transection .

SETTING

China rehabilitation research center.

OBJECTIVE

To investigate locomotor functional recovery in spinal rats with BWSTT using semiquantitative and qualitative methods.

METHODS

Five-day postoperative (dpo), adult female complete spinal rats (at T(8) level) received 40 days of body weight-supported treadmill training (BWSTT). Signs of functional recovery were examined with average combined scores (ACOS) and Basso Beattie and Bresnahan (BBB) scales at different time points.

RESULTS

At 1-dpo, none of the spinal rats exhibited hindlimb movements. The spinal rats displayed functional progress with time, but the rare could recover to full weight-bearing hindlimb at 45-dpo. BBB and ACOS scores in the BWSTT group obtained better scores than those in the spinal cord injury (SCI) group at 30- and 45-dpo. Furthermore, all BBB and ACOS scores of spinal rats reached statistical significance between 7- and 30-dpo, and between 15- and 30-dpo. However, only ACOS but not BBB scores in the SCI and BWSTT groups showed statistics differences between 15- and 45-dpo, and between 30- and 45-dpo. The Spearman correlation coefficients of BBB and ACOS scores were 0.913 and 0.972 for the SCI and BWSTT groups, respectively.

CONCLUSIONS

The results confirmed the existence of partial spontaneous hindlimb functional recovery in adult chronically spinal cord-transected rats, and that BWSTT can improve motor performance. In addition, our study suggests that qualitative and semiquantiative methods are strongly correlated with locomotor recovery in spinal rats, and the latter may be more sensitive in reflecting minor variance at different time points.

Expression of 2',3'-cyclic nucleotide 3'-phosphodiesterase in the amoeboid microglial cells in the developing rat brain

Expression of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in amoeboid microglial cells (AMC) in developing rat brain from prenatal day 18 (E18) to postnatal day 10 (P10) was demonstrated by immunohistochemistry/immunofluorescence and immunoelectron microscopy both in vivo and in vitro, respectively. Furthermore, real time-polymerase chain reaction (PCR) was performed to determine the expression of CNPase at mRNA level in cultured microglial cells in control conditions and following lipopolysaccharide stimulation. CNPase immunoreactive amoeboid microglia occurred in large numbers in the corpus callosum, subventricular zone and cavum septum pellucidum at P0 but were progressively reduced with age and were undetectable at P14. By immunoelectron microscopy, immunoreaction product was associated primarily with the plasma membrane, filopodial projections and mitochondria in AMC. Real time-PCR analysis revealed that CNPase mRNA was expressed by cultured amoeboid microglia and was significantly up-regulated in microglial activation induced in vitro by lipopolysaccharide. The functional role of CNPase in AMC remains speculative. Given its expression in AMC transiently occurring in the perinatal brain and that it is markedly elevated in activated microglia, it is suggested that the enzyme may be linked to the major functions of the cell type such as release of chemokines and cytokines. In relation to this, CNPase may play a key role associated with transportation of cytoplasmic materials.

Orbital susceptibilities of PbSe quantum dots

Different sizes of three-dimensional PbSe quantum dots have been synthesized for the study of orbital magnetic susceptibilities. Two types of orbital susceptibilities have been found, including the Curie susceptibility and finite-size corrections to the Landau susceptibility. The Curie term of a quantum dot manifests itself in the temperature dependence of magnetic susceptibility at low temperatures, while the field dependence of differential susceptibility at high temperatures shows finite-size corrections to the Landau susceptibility. Both of the two kinds of orbital susceptibility, estimated per quantum dot, show linear dependence on the size.

Breakdown of K selection in 178Hf

Coulomb activation of the four quasiparticle Kpi=16+ 178Hf isomer (t1/2=31 y) has led to the measurement of a set of Elamda matrix elements coupling the isomer band to the ground band. The present data combined with earlier 178 Hf Coulomb excitation data have probed the components in the wave functions and revealed the onset and saturation of K mixing in low-K bands, whereas the mixing is negligible in the high-K bands. The implications can be applied to other quadrupole-deformed nuclei.

Boosting nitrification by membrane-attached biofilm

Nitrification is a key step for reliable biological nitrogen removal. In order to enhance nitrification in the activated sludge (AS) process, membrane-attached biofilm (MAB) was incorporated in a conventional activated sludge tank. Simultaneous organic carbon removal and nitrification of the MAB incorporated activated sludge (AS + MAB) process was investigated with continuous wastewater treatment. The effluent TOC concentration of AS and the AS + MAB processes were about 6.3 mg/L and 7.9 mg/L, respectively. The TOC removal efficiency of both AS and AS + MAB were above 95% during the wastewater treatment, indicating excellent organic carbon removal performance in both processes. Little nitrification occurred in the AS process. On the contrary, successful nitrification was obtained with the AS + MAB process with nitrification efficiency of about 90%. The volumetric and surface nitrification rates were about 0.14 g/Ld and 6.5 g/m2d, respectively. The results clearly demonstrated that nitrification in the conventional AS process was boosted by MAB. Furthermore, the microfaunal population in the AS + MAB process was different from that in the AS process. The high concentration of rotifers in the AS + MAB process was expected to decrease the generation of excess sludge in the process.

Prolonged fever and pyuria: a urinary tract infection presentation of incomplete Kawasaki disease

We report two patients with incomplete Kawasaki disease that presented as apparent urinary tract infection. Persistent fever and pyuria were the initial presentation without concomitant signs suggestive of Kawasaki disease; thus the patients were treated as urinary tract infection. Fever persisted despite antibiotic treatment. Diagnostic criteria of Kawasaki disease were not fulfilled for these two patients, yet aneurysmal dilatation of the coronary artery was noted 10 and 18 d, respectively, after the onset of fever. The diagnosis of incomplete Kawasaki disease was assigned when the coronary artery abnormality was detected. Fever subsided within 24 h of administration of intravenous immunoglobulin.

CONCLUSION

This report highlights the potentially misleading presentation of fever and pyuria as the sole initial manifestation of incomplete Kawasaki disease. Echocardiography is indicated to detect coronary artery abnormality when fever persists in such patients after adequate antibiotic treatment and thorough urological evaluation.

Unmasking the dynamic interplay between efflux transporters and metabolic enzymes

Drug efflux by intestinal P-glycoprotein (P-gp) is known to decrease the bioavailability of many CYP3A4 substrates. We have demonstrated that the interplay between P-gp and CYP3A4 at the apical intestinal membrane can increase the opportunity for drug metabolism by determining bidirectional extraction ratios across CYP3A4-transfected Caco-2 cells for two dual P-gp/CYP3A4 substrates, K77 (an experimental cysteine protease inhibitor) and sirolimus, as well as two negative control, CYP3A4 only substrates, midazolam and felodipine. Studies were carried out under control conditions, with a P-gp inhibitor (GG918) and with a dual inhibitor (cyclosporine). Measurement of intracellular concentration changes is an important component in calculating the extraction ratios. We hypothesize that the inverse orientation of P-gp and CYP3A4 in the liver will result in an opposite interactive effect in that organ. In vivo rat intestinal perfusion studies with K77 and rat liver perfusion studies with tacrolimus under control conditions and with inhibitors of CYP3A4 (troleandomycin), P-gp (GG918) and both CYP3A4/P-gp (cyclosporine) lend support to our hypotheses. These results serve as a template for predicting enzyme-transporter (both absorptive and efflux) interactions in the intestine and the liver.

Transporter-Enzyme Interactions: Implications for Predicting Drug-Drug Interactions from In Vitro Data

As discussed in earlier articles, predictions of in vivo drug-drug interactions from in vitro studies is a subject of high interest with obvious therapeutic as well as economic benefits. Up until now little attention has been given to the potential interplay between metabolic enzymes and transporters that could confound the in vivo-in vitro relationships. Drug efflux by intestinal P-glycoprotein (P-gp) is known to decrease the bioavailability of many CYP3A4 substrates. We have demonstrated that the interplay between P-gp and CYP3A4 at the apical intestinal membrane can increase the opportunity for drug metabolism by determining bidirectional extraction ratios across CYP3A4 transfected Caco-2 cells for two dual P-gp/CYP3A4 substrates, K77 (an experimental cysteine protease inhibitor) and sirolimus, as well as two negative control, CYP3A4 only substrates, midazolam and felodipine. Studies were carried out under control conditions, with a P-gp inhibitor (GG918) and with a dual inhibitor (cyclosporine). Measurement of intracellular concentration changes is an important component in calculating the extraction ratios. We hypothesize that the inverse orientation of P-gp and CYP3A4 in the liver will result in an opposite interactive effect in that organ. In vivo rat intestinal perfusion studies with K77 and rat liver perfusion studies with tacrolimus under control conditions and with inhibitors of CYP3A4 (troleandomycin), P-gp (GG918) and both CYP3A4/P-gp (cyclosporine) lend support to our hypotheses. These results serve as a template for predicting enzyme- transporter (both absorptive and efflux) interactions in the intestine and the liver.

Different enzyme activities of sialyltransferases in gynecological cancer cell lines

PURPOSE

Due to rarity of a relationship between sialyltransferase enzyme activities and gynecological cancers, we arranged the study to evaluate sialyltransferase enzyme activity in the various kinds of gynecological cancer cell lines.

METHODS

Ten cell lines from various kinds of gynecological cancers and two cell lines from normal tissue were enrolled in this study. The activities of each subtype of sialyltransferases were detected using Gal beta1,3GalNAc-acetyl-lactosamine)-Obz1 (acceptor for ST2,3Gal I), Gal beta1,3GlcNAc beta1,3Gal beta1,4GlcNAc (acceptor for ST2,3Gal III), Gal beta1,4GlcNAc (acceptor for ST2,3Gal IV), asialo-bovine submaxillary mucin (acceptor for ST2,6GalNAc I), asialo-fetuin (acceptor for STalpha2,6GalNAc II), and fetuin (acceptor for ST2,6GalNAc III), respectively. The amounts of sialic acids were measured using fluorescein-conjugated Sambucus nigra agglutinin (SNA) specific for alpha2,6-sialic acids and fluorescein-conjugated Maackia Amurensis agglutinin (MAA) specific for alpha2,3-sialic acids.

RESULTS

The activities of two sialyltransferase subtypes, ST3Gal I & ST6GalNAc II, were significantly higher in nearly all cell lines. More specifically, cervical cancer cell line-ME 180, ovarian cancer cell line-ES-2, and choriocarcinoma cell line-BeWo showed high levels of ST3Gal I enzyme activity; all gynecological cancer cell lines except endometrial cancer cell line-RL95-2 had high levels of ST6GalNAc II enzyme activity when compared with a normal control cell line--fibroblast cell line (CCD-966Sk). Cell lines tested in this study have diverse levels of surface alpha2,6-sialic acid sugar chains (enhanced SNA binding) when compared with alpha2,3-sialic acid sugar chains (enhanced MAA binding) but we found that some cell lines such as Ca Ski (cervical cancer cell line), CC7T (cervical cancer cell line), PA-I (ovarian cancer cell line), and BeWo showed significantly altered cell surface alpha2,6-sialic acid sugar chains.

CONCLUSION

Increasing enzyme activity of ST3Gal I and ST6GalNAc II might be important in various kinds of gynecological cancers. More specifically, enhanced activity of sialyltransferases involving alpha2,6-sialic acid sugar chains might be more important in cancer development. Future studies will investigate whether the enzyme activity of these sialyltransferases can be helpful for clinical practice.

Coulomb excitation paths of high-K isomer bands in 178Hf

Three distinctly different mechanisms are shown to populate the K(pi)=6(+) (t(1/2)=77 ns), 16(+) (31 yr), and 8(-) (4 s) isomer bands of 178Hf by Coulomb excitation. High spin states of the three isomer bands were populated by Coulomb excitation of a hafnium target with a 650 MeV 136Xe beam. Although direct population of high-K bands is highly K-forbidden, isomer bands in 178Hf were populated up to spins 13(+)(K=6), 20(+)(K=16), and 14(-)(K=8) with in-band gamma yields of approximately 10(-4) of the ground state band. The data are consistent with a rapid increase in K mixing with increasing spin in the isomer bands.