Diagnosis of ultrafast surface dynamics of thin foil targets irradiated by intense laser pulses

The temporal modulation of an electron bunch train accelerated from a foil target irradiated by an intense laser pulse is studied by measuring the coherent transition radiation (CTR) from the rear surface of a target. We experimentally obtained CTR spectra from a 1 µm thick foil target irradiated at a maximum intensity of 6.5 × 10¹⁹ W/cm². Spectral redshifts of the emitted radiation corresponding to increases in laser intensity were observed. These measurements were compared with the theoretical calculation of CTR spectra considering ultrafast surface dynamics, such as plasma surface oscillation and relativistically induced transparency. Plasma surface oscillations induce a spectral redshift, while relativistic transparency causes a spectral blueshift. Both effects are required to find reasonable agreement with the experiment over the entire range of laser intensities.

Abstract 4327: Hypermethylation of miR193b reactivates master drivers of the poor prognosis prostate cancer

Epigenetic silencing of miRNAs is one of the major mechanisms of aberrant miRNA expression in cancer. Several studies showed that hypermethylation of miRNAs contributes to prostate cancer (PC) initiation and progression. Recent screening for epigenetically regulated miRNAs in PC revealed hypermethylation of the miR-193b in tumor, but no related functional studies of miR-193b have been pursued. miR-193b functions as a tumor suppressor in various cancer by targeting multiple oncogenic pathways. Methylation regulated miR-193b silencing has been observed in multiple cancer types. In this study, we aimed to elucidate the function of miR-193b and related molecular mechanisms in PC. In TCGA cohort, we observed a significant correlation between methylation of the miR-193b and its expression level. We further confirmed that some of PC cell lines recapitulate the methylation of miR-193b seen in clinical samples. The phenotypes induced by exogenous miR-193b in PC cell lines showed the tumor suppressive property of miR-193b. Since some of miRNA-target interactions are conserved across organisms, we selected the top 150-downregulated genes by miR-193b in liposarcoma from public available datasets and unraveled the correlation between these genes with PC progression. We further applied the 150 genes to the PC subtype (PCS) signatures. There were 41 genes overlapping with the aggressive PCS1 among 150 genes, indicating miR-193b may affect these key 41 genes that regulate PC progression. The inhibition of the 41 genes by miR-193b was validated in multiple PC cell lines. Furthermore, high expression of these genes was highly correlated with recurrence of PC. The GSEA analysis of 41 genes revealed high enrichment in the FOXM1 target network. We further identified FOXM1 as a direct target of miR-193b and overexpression of FOXM1 is highly correlated with clinical outcomes including metastasis and lethality. Besides FOXM1, we also identified RRM2 as another important target of miR-193b, which is part of the PCS1 signature. Knockdown of RRM2 phenocopied miR-193b in PC cells. Its overexpression is highly correlated clinical outcomes. To explore the therapeutic potential of regulating miR-193b levels, we restored miR-193b expression by using combination treatment with DNMT and HDAC inhibitors (5-azacytidine and mocetinostat), resulting in the inhibition of FOXM1 and RRM2 expression. Interestingly, FOXM1 and RRM2 expression are highly correlated in multiple PC cohorts. All together, we revealed the tumor suppressive function of miR-193b in PC. A 41-gene set was identified and validated as the targets of miR-193b in PC cells, and showed a high correlation with PC progression in multiple PC cohorts. FOXM1 and RRM2 may be the key targets of miR-193b in PC. Our findings suggest that hypermethylation of miR-193b in PC may release the inhibition of some key oncogenes that contribute PC progression.

Citation Format: Ying Z. Mazzu, Yuki Yoshikawa, Subhiksha Nandakumar, Joshua Armenia, Lina Jehane, Gwo-Shu Lee, Goutam Chakraborty, Philp Kantoff. Hypermethylation of miR193b reactivates master drivers of the poor prognosis prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4327.

Surface Area Enhancement of Nanomechanical Disk Resonators Using MWCNT for Mass-Sensing Applications

This work presents fabrication of thermal-piezoresistive nanoelectromechanical silicon disk resonators and their characterization as highly sensitive mass sensors. Forest of multiwall carbon nanotubes (MWCNTs) has been grown on the top surface of the fabricated devices, increasing the resonator effective surface area, which, in turn, increases the adsorption capacity and, therefore, the frequency shift of the sensor in molecular or particulate detection applications. To investigate the effect of the enhanced surface area on frequency shift, devices with and without MWCNTs were exposed to an aqueous solution of manganese sulfate for different deposition times and the resonance frequency shift was recorded accordingly. The measured frequency shift for the devices covered with MWCNTs was 14× higher than similar bare silicon devices. Furthermore, mass loading experiments were performed using gold nanoparticles as the loading mass. A novel way to attach gold nanoparticles on the carbon nanotubes (CNTs) wall was developed here. Oxygen plasma treatment introduced dangling bonds on the MWCNTs walls to facilitate the bonding between them and trimethoxysilane aldehyde molecules, forming the self-assembled monolayer (SAM). After functionalization of the device with SAM and antiinfluenza H1N1 viruses (AB), the device was exposed to a solution of Antimouse IgG (whole molecule)-gold antibody produced in goat products. The results showed more than three times response enhancement for the resonators with MWCNTs.

Galectin-9 suppresses B cell receptor signaling and is regulated by I-branching of N-glycans

Leukocytes are coated with a layer of heterogeneous carbohydrates (glycans) that modulate immune function, in part by governing specific interactions with glycan-binding proteins (lectins). Although nearly all membrane proteins bear glycans, the identity and function of most of these sugars on leukocytes remain unexplored. Here, we characterize the N-glycan repertoire (N-glycome) of human tonsillar B cells. We observe that naive and memory B cells express an N-glycan repertoire conferring strong binding to the immunoregulatory lectin galectin-9 (Gal-9). Germinal center B cells, by contrast, show sharply diminished binding to Gal-9 due to upregulation of I-branched N-glycans, catalyzed by the β1,6-N-acetylglucosaminyltransferase GCNT2. Functionally, we find that Gal-9 is autologously produced by naive B cells, binds CD45, suppresses calcium signaling via a Lyn-CD22-SHP-1 dependent mechanism, and blunts B cell activation. Thus, our findings suggest Gal-9 intrinsically regulates B cell activation and may differentially modulate BCR signaling at steady state and within germinal centers.

Outcomes of organ transplants when the donor is a prior recipient

Organ shortage continues to challenge the field of transplantation. One potential group of donors are those who have been transplant recipients themselves, or Organ Donation After Transplant (ODAT) donors. We conducted a retrospective cohort study to describe ODAT donors and to compare outcomes of ODAT grafts versus conventional grafts. From October 1, 1987 to June 30, 2015, 517 former recipients successfully donated 803 organs for transplant. Former kidney recipients generally survived a median of approximately 4 years before becoming an ODAT donor whereas liver, lung, and heart recipients generally survived less than a month prior to donation. In the period June 1, 2005 to December 31, 2014, liver grafts from ODAT donors had a significantly higher risk of graft failure compared to non-ODAT liver transplants (P = .008). Kidney grafts donated by ODAT donors whose initial transplant occurred >1 year prior were associated with significantly increased graft failure (P = .012). Despite increased risk of graft failure amongst certain ODAT grafts, 5-year survival was still high. ODAT donors should be considered another form of expanded criteria donor under these circumstances.

Abstract 4740: Loss of the tumor suppressor zinc finger protein-36 and risk of lethal prostate cancer

Background. Biomarkers are needed to complement current clinicopathologic variables towards distinguishing prostate tumors that are likely to be metastatic from those that are indolent. We previously used a bioinformatic analytical approach to identify ZFP36, also known as Tristetraprolin (TTP), as a tumor suppressor in the NFκB pathway. The current study aims to evaluate the prognostic potential of tumor mRNA expression of ZFP36.

Methods. Our primary analysis leveraged data from a case-control study nested in the Health Professionals Follow-up Study and Physicians’ Health Study. Gene expression for ZFP36 was quantified from archival surgical tumor tissue using Affymetrix Human Gene 1.0 ST microarrays. Cases (n=113) were men who died of prostate cancer or developed metastatic disease, and controls (n=291) were men who lived at least 8 years after diagnosis and remained metastasis free. A genetically validated PTEN immunohistochemistry (IHC) assay was performed on tissue microarrays (TMAs) for a subset of the men (n=257).

Results. Mean ZFP36 expression was significantly lower in the cases compared to the controls (p<0.001), and the crude odds ratio (OR) for lethal disease comparing those with low ZFP36 expression (below the lower quartile) to those with high ZFP36 expression (greater than or equal to the lower quartile) was 3.52 (95% CI: 2.18-5.69; p<0.001). The association persisted with adjustment for Gleason category, age at diagnosis, and clinical stage, with an adjusted OR of 1.93 (95% CI: 1.07-3.49; p=0.03). When modeled as a continuous variable in a logistic regression for prognosis, ZFP36 improved the AUC of the clinical factor model (Gleason, age, and clinical stage) from 0.83 (95% CI: 0.79-0.88) to 0.85 (95% CI: 0.81-0.89; p=0.10 for improvement).

Among the patients with available PTEN staining, independent effects of ZFP36 and PTEN loss were observed. In the logistic regression on lethal disease with both variables included, PTEN negativity conferred an OR of 2.10 (95% CI: 1.11-3.93; p=0.02) and low ZFP36 produced an OR of 2.34 (95% CI: 1.24-4.36; p=0.01). Taken together, we observed an OR of 4.90 (95% CI: 2.05-11.72) comparing patients with PTEN negativity and low ZFP36 to those with PTEN staining present and high ZFP36.

Conclusions. Loss of the tumor suppressor ZFP36 is prognostic for metastatic or lethal prostate cancer. Combining information on ZFP36 with measurements from other mechanistic pathways, such as PTEN, may lead to highly accurate models.

Citation Format: Travis Gerke, Daniela Börnigen, Himisha Beltran, Svitlana Tyekucheva, Curtis Huttenhower, Gwo-Shu Lee, Bruce Trock, Lorelei Mucci, Christopher Sweeney. Loss of the tumor suppressor zinc finger protein-36 and risk of lethal prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4740. doi:10.1158/1538-7445.AM2017-4740

Computational Reconstruction of NFκB Pathway Interaction Mechanisms during Prostate Cancer

Molecular research in cancer is one of the largest areas of bioinformatic investigation, but it remains a challenge to understand biomolecular mechanisms in cancer-related pathways from high-throughput genomic data. This includes the Nuclear-factor-kappa-B (NFκB) pathway, which is central to the inflammatory response and cell proliferation in prostate cancer development and progression. Despite close scrutiny and a deep understanding of many of its members’ biomolecular activities, the current list of pathway members and a systems-level understanding of their interactions remains incomplete. Here, we provide the first steps toward computational reconstruction of interaction mechanisms of the NFκB pathway in prostate cancer. We identified novel roles for ATF3, CXCL2, DUSP5, JUNB, NEDD9, SELE, TRIB1, and ZFP36 in this pathway, in addition to new mechanistic interactions between these genes and 10 known NFκB pathway members. A newly predicted interaction between NEDD9 and ZFP36 in particular was validated by co-immunoprecipitation, as was NEDD9's potential biological role in prostate cancer cell growth regulation. We combined 651 gene expression datasets with 1.4M gene product interactions to predict the inclusion of 40 additional genes in the pathway. Molecular mechanisms of interaction among pathway members were inferred using recent advances in Bayesian data integration to simultaneously provide information specific to biological contexts and individual biomolecular activities, resulting in a total of 112 interactions in the fully reconstructed NFκB pathway: 13 (11%) previously known, 29 (26%) supported by existing literature, and 70 (63%) novel. This method is generalizable to other tissue types, cancers, and organisms, and this new information about the NFκB pathway will allow us to further understand prostate cancer and to develop more effective prevention and treatment strategies.

In molecular research in cancer it remains challenging to uncover biomolecular mechanisms in cancer-related pathways from high-throughput genomic data, including the Nuclear-factor-kappa-B (NFκB) pathway. Despite close scrutiny and a deep understanding of many of the NFκB pathway members’ biomolecular activities, the current list of pathway members and a systems-level understanding of their interactions remains incomplete. In this study, we provide the first steps toward computational reconstruction of interaction mechanisms of the NFκB pathway in prostate cancer. We identified novel roles for 8 genes in this pathway and new mechanistic interactions between these genes and 10 known pathway members. We combined 651 gene expression datasets with 1.4M interactions to predict the inclusion of 40 additional genes in the pathway. Molecular mechanisms of interaction were inferred using recent advances in Bayesian data integration to simultaneously provide information specific to biological contexts and individual biomolecular activities, resulting in 112 interactions in the fully reconstructed NFκB pathway. This method is generalizable, and this new information about the NFκB pathway will allow us to further understand prostate cancer.

Hepatic differentiation of porcine embryonic stem cells for translational research of hepatocyte transplantation

Porcine embryonic stem cells (ES) are considered attractive preclinical research tools for human liver diseases. Although several studies previously reported generation of porcine ES, none of these studies has described hepatic differentiation from porcine ES. The aim of this study was to generate hepatocytes from porcine ES and analyze their characteristics. We optimized conditions for definitive endoderm induction and developed a 4-step hepatic differentiation protocol. A brief serum-free condition with activin A efficiently induced definitive endoderm differentiation from porcine ES. The porcine ES-derived hepatocyte-like cells highly expressed hepatic markers including albumin and α-fetoprotein, and displayed liver characteristics such as glycogen storage, lipid production, and low-density lipoprotein uptake. For the first time, we describe a highly efficient protocol for hepatic differentiation from porcine ES. Our findings provide valuable information for translational liver research using porcine models, including hepatic regeneration and transplant studies, drug screening, and toxicology.

Supramolecular interaction of 6-shogaol, a therapeutic agent of Zingiber officinale with human serum albumin as elucidated by spectroscopic, calorimetric and molecular docking methods

BACKGROUND

6-Shogaol, one of the main bioactive constituents of Zingiber officinale has been shown to possess various therapeutic properties. Interaction of a therapeutic compound with plasma proteins greatly affects its pharmacokinetic and pharmacodynamic properties.

PURPOSE

The present investigation was undertaken to characterize the interaction between 6-shogaol and the main in vivo transporter, human serum albumin (HSA).

METHODS

Various binding characteristics of 6-shogaol-HSA interaction were studied using fluorescence spectroscopy. Thermal stability of 6-shogaol-HSA system was determined by circular dichroism (CD) and differential scanning calorimetric (DSC) techniques. Identification of the 6-shogaol binding site on HSA was made by competitive drug displacement and molecular docking experiments.

RESULTS

Fluorescence quench titration results revealed the association constant, Ka of 6-shogaol-HSA interaction as 6.29 ± 0.33 × 10(4) M(-1) at 25 ºC. Values of the enthalpy change (-11.76 kJ mol(-1)) and the entropy change (52.52 J mol(-1) K(-1)), obtained for the binding reaction suggested involvement of hydrophobic and van der Waals forces along with hydrogen bonds in the complex formation. Higher thermal stability of HSA was noticed in the presence of 6-shogaol, as revealed by DSC and thermal denaturation profiles. Competitive ligand displacement experiments along with molecular docking results suggested the binding preference of 6-shogaol for Sudlow's site I of HSA.

CONCLUSION

All these results suggest that 6-shogaol binds to Sudlow's site I of HSA through moderate binding affinity and involves hydrophobic and van der Waals forces along with hydrogen bonds.

Serum levels of sclerostin, Dickkopf-1, and secreted frizzled-related protein-4 are not changed in individuals with high bone mass causing mutations in LRP5

SUMMARY

We compared circulating levels of Wnt inhibitors among patients with high bone mass mutations in LRP5, unaffected kindred, and unrelated normal controls. Inhibitors were unchanged in affected and unaffected kindred. We saw no meaningful differences between controls and affected individuals. LRP5 signaling may not influence circulating levels of these inhibitors.

INTRODUCTION

It is thought that gain-of-function mutations in LRP5 result in high bone mass syndromes because these allelic variants confer resistance to the actions of endogenous inhibitors of Wnt signaling. We therefore attempted to determine if circulating levels of Wnt inhibitors are altered in patients with gain-of-function mutations in LRP5.

METHODS

This is a cross-sectional study in a university research center. Serum was collected from consented volunteers known to have either the G171V or N198S gain-of-function mutations in LRP5, kindred members affected with either mutation, unrelated kindred, and unrelated normal age-matched controls. BMD was provided or measured on site.

RESULTS

There were no significant differences found in the serum levels of sclerostin (SOST), Dickkopf-1 (Dkk-1), or secreted frizzled-related protein-4 (SFRP-4) in affected vs. unaffected individuals from different kindreds or when compared to age-matched unrelated normal individuals. Mean serum SOST values in affected and unaffected kindred members and unrelated normal controls were 52.7 ± 6.1, 36.5 ± 9.6, and 54.8 ± 5.4, respectively. For Dkk-1, the values were 25.9 ± 3.4, 25.7 ± 3.0, and 17.3 ± 2.3 and for SFRP-4, 38.1 ± 2.3, 39.8 ± 3.6, and 28.5 ± 1.7. Serum levels of RANKL and osteoprotegerin (OPG) were not different in the three groups.

CONCLUSIONS

Circulating levels of endogenous Wnt inhibitors do not change in patients with gain-of-function mutations in LRP5 including Dkk1, which is suppressed by Wnt signaling. It may be that circulating levels of Wnt inhibitors do not reflect changes in target tissues. It is also possible that other mechanisms besides or in addition to resistance in Wnt inhibitors explains the skeletal effects of these mutations.

Observation of a p-wave one-neutron halo configuration in (37)Mg

Cross sections of 1n-removal reactions from the neutron-rich nucleus (37)Mg on C and Pb targets and the parallel momentum distributions of the (37)Mg residues from the C target have been measured at 240  MeV/nucleon. A combined analysis of these distinct nuclear- and Coulomb-dominated reaction data shows that the (37)Mg ground state has a small 1n separation energy of 0.22(-0.09)(+0.12)  MeV and an appreciable p-wave neutron single-particle strength. These results confirm that (37)Mg lies near the edge of the "island of inversion" and has a sizable p-wave neutron halo component, the heaviest such system identified to date.

Attenuated benzodiazepine-sensitive tonic GABAA currents of supraoptic magnocellular neuroendocrine cells in 24-h water-deprived rats

In supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs), γ-GABA, via activation of GABAA receptors (GABAA Rs), mediates persistent tonic inhibitory currents (Itonic ), as well as conventional inhibitory postsynaptic currents (IPSCs, Iphasic ). In the present study, we examined the functional significance of Itonic in SON MNCs challenged by 24-h water deprivation (24WD). Although the main characteristics of spontaneous IPSCs were similar in 24WD compared to euhydrated (EU) rats, Itonic , measured by bicuculline (BIC)-induced Iholding shifts, was significantly smaller in 24WD compared to EU rats (P < 0.05). Propofol and diazepam prolonged IPSC decay time to a similar extent in both groups but induced less Itonic in 24WD compared to EU rats, suggesting a selective decrease in GABAA receptors mediating Itonic over Iphasic in 24WD rats. THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol), a preferential δ subunit agonist, and L-655,708, a GABAA receptor α5 subunit selective imidazobenzodiazepine, caused a significantly smaller inward and outward shift in Iholding , respectively, in 24WD compared to EU rats (P < 0.05 in both cases), suggesting an overall decrease in the α5 subunit-containing GABAA Rs and the δ subunit-containing receptors mediating Itonic in 24WD animals. Consistent with a decrease in 24WD Itonic , bath application of GABA induced significantly less inhibition of the neuronal firing activity in 24WD compared to EU SON MNCs (P < 0.05). Taken together, the results of the present study indicate a selective decrease in GABAA Rs functions mediating Itonic as opposed to those mediating Iphasic in SON MNCs, demonstrating the functional significance of Itonic with respect to increasing neuronal excitability and hormone secretion in 24WD rats.

Evaluation of 8q24 and 17q risk loci and prostate cancer mortality

PURPOSE

Variants at chromosomal loci 8q24 and 17q are established risk factors for prostate cancer. Many studies have confirmed the findings for risk, but few have examined aggressiveness and other clinical variables in detail. Additionally, Gleason score is typically used as a surrogate for the primary end point of prostate cancer mortality. We investigated whether the 8q24 and 17q risk variants are associated with clinical variables as well as prostate cancer mortality.

EXPERIMENTAL DESIGN

In the Physicians' Health Study (1,347 cases and 1,462 controls), the Dana-Farber Harvard Cancer Center Specialized Program of Research Excellence (Gelb Center; 3,714 cases), and the Fred Hutchinson Cancer Research Center King County Case-Control Studies (1,308 cases and 1,266 controls), we examined eight previously identified 8q24 and 17q risk variants for association with prostate cancer mortality in men of European ancestry. We considered associations with other surrogate markers of prostate cancer aggressiveness, such as Gleason score, pathologic stage, prostate-specific antigen at diagnosis, and age at diagnosis.

RESULTS

Six of the eight variants were confirmed as prostate cancer risk factors. Several variants were nominally associated with age at diagnosis; when totaling all alleles for single nucleotide polymorphisms significantly associated with risk, each additional allele decreased age at diagnosis by an average of 6 months in the Physicians' Health Study (P = 0.0005) and 4 months in the Dana-Farber Harvard Cancer Center Specialized Program of Research Excellence (Gelb Center) cohort (P = 0.0016). However, there were no statistically significant associations with prostate cancer mortality.

CONCLUSIONS

Our results suggest that the 8q24 and 17q prostate cancer risk variants may influence age at diagnosis but not disease aggressiveness.

Relationship between serum adiponectin and prostate cancer grade

BACKGROUND

Obesity is associated with prostate cancer (PCA) grade, but the mechanism behind this relationship is not understood. Adiponectin is an adipokine that has been linked with the development of hormonally sensitive carcinomas, including prostate cancer. We evaluated the relationship between serum adiponectin and Gleason score (GS) in a prospective series of patients seen in a single institution.

METHODS

Localized PCA patients evaluated at Dana-Farber Cancer Institute between 2001 and 2005 who enrolled in a prospective serum banking protocol were eligible for this study. Patients with prior hormonal therapy and/or metastatic disease were excluded. High-grade disease was defined as biopsy or radical prostatectomy (RP) GS of 7 or higher. Logistic regression models were used to assess the relationship between high-grade disease and adiponectin levels while adjusting for other potential prognostic variables.

RESULTS

There were 539 patients included in this study, of whom 199 had undergone RP. Median age was 60 years. Median PSA was 5.1 ng/dl. Biopsy GS of 7 or higher was seen in 46.9% of patients. For biopsy GS, higher PSA, older age, and higher BMI were significantly associated with increased odds of GS 7 or higher, but adiponectin was not. In men undergoing RP, there was a significant inverse relationship between pathologic GS and adiponectin dichotomized at the median, due to a significantly higher rate of upgrading in patients with lower adiponectin (P = 0.014).

CONCLUSIONS

Although there was no association between biopsy GS and adiponectin, in patients who had undergone RP, lower adiponectin was independently associated with high-grade prostate cancer.

The pharmacodynamics of mivacurium in the rabbit with carbon tetrachloride-induced liver disease

BACKGROUND AND OBJECTIVE

Neuromuscular blocking effects according to the severity of liver dysfunction have not been evaluated. We assessed the neuromuscular effects of mivacurium in carbon tetrachloride (CCl4)-treated rabbits with toxic hepatitis in vivo.

METHODS

We compared the dose-response relationships and the neuromuscular blocking effects of mivacurium in 66 rabbits randomly treated with 0.3 mL kg(-1) of corn oil, 0.3 mL kg(-1) of CCl4 or 0.6 mL kg(-1) of CCl4 for 11 weeks, respectively. Train-of-four stimuli were applied every 10 s to the common peroneal nerve and the force of contraction of the tibialis anterior muscle was measured.

RESULTS

Severe hepatitis was associated with a rightward shift of the mivacurium dose-response curves, but mild hepatitis had no effect. The calculated ED50 values for the control, mild and severe hepatitis were 17.1+/-2.6, 18.2+/-2.7 and 31.8+/-3.2 microg kg(-1), respectively. Rabbits with severe hepatitis had a significantly prolonged recovery time from neuromuscular blockade compared with other rabbits. Cholinesterase activity had a negative correlation with recovery indices of mivacurium even in severe hepatic injury. Severe hepatitis induced a prolongation of action duration of repeated doses, but maintained the constant intervals.

CONCLUSIONS

The dose-response and the time course of neuromuscular blockade of mivacurium differ in mild hepatitis compared with severe hepatitis, but required no adjustments of different doses for repeated injection after the desired depth of neuromuscular block, and had a negative correlation with the activity of plasma cholinesterase in both hepatic injuries.

Carbon nanotubes based methanol sensor for fuel cells application

An electrochemical sensor is built using vertically grown multi-walled carbon nanotubes (MWNTs) micro-array to detect methanol concentration in water. This study is done for the potential use of the array as methanol sensor for portable units of direct methanol fuel cells (DMFCs). Platinum (Pt) nanoparticles electro-deposited CNTs (Pt/CNTs) electrode shows high sensitivity in the measurement of methanol concentration in water with cyclic voltammetry (CV) measurement at room temperature. Further investigation has also been undertaken to measure the concentration by changing the amount of the mixture of methanol and formic acid in water. We compared the performance of our micro array sensor built with Pt/CNTs electrodes versus that of Pt wire electrode using CV measurement. We found that our Pt/CNTs array sensor shows high sensitivity and detects methanol concentrations in the range of 0.04 M to 0.10 M. In addition, we found that co-use of formic acid as electrolyte enables us to measure up to 1.0 M methanol concentration.

The analysis of telomere length and telomerase activity in cloned pigs and cows

Inefficiency in the production of cloned animals is most likely due to epigenetic reprogramming errors after somatic cell nuclear transfer (SCNT). In order to investigate whether nuclear reprogramming restores cellular age of donor cells after SCNT, we measured telomere length and telomerase activity in cloned pigs and cattle. In normal pigs and cattle, the mean telomere length was decreased with biological aging. In cloned or transgenic cloned piglets, the mean telomere length was elongated compared to nuclear donor fetal fibroblasts and age-matched normal piglets. In cloned cattle, no increases in mean telomere length were observed compared to nuclear donor adult fibroblasts. In terms of telomerase activity, significant activity was observed in nuclear donor cells and normal tissues from adult or new-born pigs and cattle, with relatively higher activity in the porcine tissues compared to the bovine tissues. Cloned calves and piglets showed the same level of telomerase activity as their respective donor cells. In addition, no difference in telomerase activity was observed between normal and transgenic cloned piglets. However, increased telomerase activity was observed in porcine SCNT blastocysts compared to nuclear donor cells and in vitro fertilization (IVF)-derived blastocysts, suggesting that the elongation of telomere lengths observed in cloned piglets could be due to the presence of higher telomerase activity in SCNT blastocysts. In conclusion, gathering from the comparative studies with cattle, we were able to demonstrate that telomere length in cloned piglets was rebuilt or elongated with the use of cultured donor fetal fibroblasts.

Effect of maturation media and oocytes derived from sows or gilts on the development of cloned pig embryos

In order to develop a culture system and recipient cytoplasm that could improve the developmental competence of somatic cell nuclear transfer (SCNT) embryos for successful cloning of pigs, we evaluated the effect of donor oocytes and in vitro maturation (IVM) media on maturation of oocytes and developmental competence of SCNT embryos. In Experiment 1, oocytes derived from sows or gilts were matured in two IVM media (TCM-199 versus NCSU-23) and maturation of oocytes was evaluated by the status of chromatin configuration, the diameter of matured oocytes, the thickness of the zona pellucida, and the size of the perivitelline space (PVS). Sow oocytes matured in TCM-199 (S-TCM group) and NCSU-23 (S-NCSU group) showed significantly higher (P<0.05) maturation rates (S-TCM and S-NSCU, 86+/-4 and 82+/-4%, respectively) when evaluated by metaphase-II status than the gilt oocytes matured in TCM-199 (G-TCM group, 71+/-3%) and in NCSU-23 (G-NCSU-23 group, 71+/-3%). Oocyte diameter, the thickness of the zona pellucida, and the perivitelline space of sow oocytes (S-TCM and S-NCSU) were larger than those of gilt oocytes (G-TCM and G-NCSU) after IVM (P<0.05). In Experiment 2, SCNT was performed, using in vitro-matured oocytes from each group as recipient cytoplasm and porcine fetal fibroblasts as karyoplasts. The reconstructed embryos were electrically fused and activated, and cleavage and blastocyst formation were monitored under a stereomicroscope. The total cell number of flattened blastocysts stained with 5 microM bisbenzimide on day 7 were counted. In addition, in vitro matured non-enucleated oocytes were also electrically activated (parthenogenetic activation) and pronuclear formation was monitored. No difference in pronuclear formation rate after parthenogenetic activation and fusion rate after SCNT was observed among experimental groups. A significantly higher cleavage rate (P<0.05) was observed in S-TCM (69+/-4%) when compared with only G-NCSU (58+/-4%), but not with G-TCM (60+/-4%) or S-NCSU (68+/-4%). The rate of blastocyst formation was significantly higher (P<0.05) in sow oocytes (24% in S-TCM and S-NCSU), when compared to that observed in G-TCM (15%), and G-NCSU (14%). When the same source of oocytes was used, there was no significant difference in rate of blastocyst formation in the two culture media. Total cell number of blastocysts were not significantly different among experimental groups. In conclusion, the present study clearly demonstrated that sow oocytes have a greater developmental competence than gilt oocytes, regardless of the maturation medium examined.

Liquid chromatographic resolution of biphenyl dimethyl dicarboxylate (DDB) and its analogues on a chiral stationary phase

Racemic biphenyl dimethyl dicarboxylate (DDB) and its analogues have been successfully resolved on a commercial HPLC chiral column, (3R,4S)-Whelk-O 1. In general, cyclic amide analogues of DDB, which were derived from pyrrolidine or piperidine, showed greater enantioselectivity and greater retention than the corresponding N,N-dialkyl amide or N-alkyl amide or ester analogues. From these results, it was concluded that the carbonyl oxygen of the DDB analogues plays an important role as a hydrogen bond acceptor, though the steric bulkiness of the amide functionality of DDB analogues may be another factor governing chiral recognition. The conformational stability of the two enantiomers of DDB and its analogues was also found to be high enough for the two enantiomers to be resolvable on (3R,4S)-Whelk-O 1.

Associations of lead biomarkers and delta-aminolevulinic acid dehydratase and vitamin D receptor genotypes with hematopoietic outcomes in Korean lead workers

OBJECTIVES

This study compares and contrasts associations of dimercaptosuccinic acid (DMSA)-chelatable lead, tibia lead, and blood lead with five hematopoietic outcomes and evaluates the effect modification of these relations by polymorphisms in the delta-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genes.

METHODS

A cross-sectional study of 798 lead workers and 135 unexposed referents was performed.

RESULTS

The DMSA-chelatable lead, tibia lead, and blood lead levels ranged in the lead (Pb) workers from 4.8 to 2103 g, -7 to 338 g Pb/g bone mineral, and 4 to 86 g/dl, respectively. The mean of the hemoglobin, hematocrit, zinc protoporphyrin (ZPP), and urinary (ALAU) and plasma (ALAP) delta-aminolevulinic acid levels of the lead workers were 14.2 (SD 1.4) g/dl, 42.4 (SD 4.4)%, 80.2 (SD 63.5) g/dl, 2.1 (SD 3.7) mg/l, and 17.7 (20.6) g/ml, respectively. After adjustment for the covariates, tibia lead was associated with all five hematopoietic outcomes, while blood lead and DMSA-chelatable lead were associated only with ZPP, ALAP, and ALAU. A comparison of the regression coefficients, total model adjusted R2 values, and delta R2 values revealed that blood lead was the best predictor of ZPP, ALAP, and ALAU. Only tibia lead was significantly associated with hemoglobin and hematocrit levels, but the additional variance explained by tibia lead was (<1%). No clear effect modification of the relations between the lead biomarkers and hematopoietic outcomes studied was caused by ALAD or VDR genotype.

CONCLUSIONS

Lead must have a chronic, cumulative effect on hemoglobin and hematocrit levels, and any speculated mechanism cannot merely involve short-term plasma or target organ lead levels.

Layer-by-layer assembly of zeolite crystals on glass with polyelectrolytes as ionic linkers

ZSM-5 crystals and glass plates tethered with trimethylpropylammonium iodide and sodium butyrate, respectively, (denoted as Z+, Z-, G+, and G-, respectively) were prepared. Treatment of G- with Z+ suspended in ethanol results in monolayer assembly of Z+ on G- (G-/Z+) with high surface coverage. The zeolite crystals have a strong tendency to closely pack and align with the b-axis normal to the glass plate, despite large positive zeta potentials. Subsequent treatment of G-/Z+ with Z- leads to second-layer assembly of Z- on G-/Z+ (G-/Z+/Z-), but with rather poor coverage. Sequential treatment of G+ with poly(sodium 4-styrenesulfonate)(Na+PSS-), poly(diallyldimethylammonium chloride) (PDDA+Cl-), and Na+PSS- followed by Z+ yields glass plates assembled with monolayers of Z+ with very high surface coverage through the composite polyelectrolyte linkers (G+/PSS-/PDDA+/PSS-/Z+). The zeolite crystals also have a strong tendency to closely pack and align with the b-axis perpendicular to the substrate plane. The binding strength between the zeolite crystals and glass plates is much higher in G+/PSS-/PDDA+/PSS-/Z+ than in G-/Z+. Repetition of the sequential PSS-/PDDA+/PSS-/Z+ layering for five cycles yields glass plates assembled with pentalayers of ZSM-5 crystals [G+/(PSS-/PDDA+/PSS-/Z+)(5)]. The observed degrees of coverage and alignment of zeolite crystals in each layer were very high up to the third layers despite the nonuniformity of the sizes and shapes of the zeolite crystals used in this study. This report thus demonstrates the feasibility of layer-by-layer assembly of micrometer-sized zeolite crystals on glass through electrostatic interaction between surface-bound, full-fledged ionic centers, especially by use of polyelectrolyes as the linkers.

Characterization of D1Pas1, a mouse autosomal homologue of the human AZFa region DBY, as a nuclear protein in spermatogenic cells

OBJECTIVE

To gain insight into the function of D1Pas1 in spermatogenesis.

DESIGN

The cellular and subcellular distribution of D1Pas1 protein were examined.

SETTING

Academic research laboratory.

ANIMALS

Swiss Webster and C57B1/6J mice.

INTERVENTION(S)

Antibodies were generated against a D1Pas1 fusion protein. Immunoblot analysis was performed on lysates of testicular cells separated into enriched populations of spermatogenic cells and fractionated into nuclear and cytoplasmic compartments. Immunohistochemistry was performed on histological sections of testis from adult and postnatal day 17 mice.

MAIN OUTCOME MEASURE(S)

D1Pas1 protein distribution.

RESULT(S)

D1Pas1 was expressed in germ cells, and its expression was developmentally regulated because it was detected specifically in the meiotic and postmeiotic haploid stages of spermatogenesis. D1Pas1 protein was predominantly localized in the nucleus, with weak cytoplasmic staining.

CONCLUSION(S)

Nuclear localization of D1Pas1 in the testis and its sequence homology to putative RNA helicases suggests a role of D1Pas1 in pre-mRNA processing during spermatogenesis. Germ cell expression of D1Pas1 and homology to the Y chromosome gene DBY, which is located in an area deleted in azoospermia, suggests a potential role for an autosomal gene in the regulation of spermatogenesis.

Effects of specific monoclonal antibodies to dense granular proteins on the invasion of Toxoplasma gondii in vitro and in vivo

Although some reports have been published on the protective effect of antibodies to Toxoplasma gondii surface membrane proteins, few address the inhibitory activity of antibodies to dense granular proteins (GRA proteins). Therefore, we performed a series of experiments to evaluate the inhibitory effects of monoclonal antibodies (mAbs) to GRA proteins (GRA2, 28 kDa; GRA6, 32 kDa) and surface membrane protein (SAG1, 30 kDa) on the invasion of T. gondii tachyzoites. Passive immunization of mice with one of three mAbs following challenge with a lethal dose of tachyzoites significantly increased survival compared with results for mice treated with control ascites. The survival times of mice challenged with tachyzoites pretreated with anti-GRA6 or anti-SAG1 mAb were significantly increased. Mice that received tachyzoites pretreated with both mAb and complement had longer survival times than those that received tachyzoites pretreated with mAb alone. Invasion of tachyzoites into fibroblasts and macrophages was significantly inhibited in the anti-GRA2, anti-GRA6 or anti-SAG1 mAb pretreated group. Pretreatment with mAb and complement inhibited invasion of tachyzoites in both fibroblasts and macrophages. These results suggest that specific antibodies to dense-granule molecules may be useful for controlling infection with T. gondii.

Gait and pedobarographic patterns of surgically treated clubfeet

Gait analysis and pedobarography were done on 58 surgically corrected clubfeet in 40 children. The average age of patients at the time of surgery was 6.7 months. The average age of the children at the time of the gait analysis was 6.1 years. Twenty-two children (32 feet) were 5 years old and younger. Eighteen children (26 feet) were older than 5 years old. Cadence, velocity, duration of single-limb stance, step length, and ground reaction force measurements were not significantly different from normal children. Differences noted in clubfeet were: 1) duration of single-limb stance among bilateral clubfeet did not increase with age; 2) increased ankle plantarflexion between opposite foot-strike and toe-off was not present; 3) the feet were internally rotated throughout (toe-in gait); 4) anterior and lateral ground reaction force measurements revealed differing trends with age; and 5) mid- and forefoot pressures increased in the surgically treated group. Gait analysis and pedobarography could detect more subtle abnormalities in corrected clubfeet and provide more objective assessments of persistent deformities.

Immobilization of poly(ethylene glycol) or its sulfonate onto polymer surfaces by ozone oxidation

A novel surface modification method has been developed to improve biocompatibility of polymeric biomaterials. This approach involves ozonation and then followed by graft polymerization with acrylates containing PEG, sulfonated PEG or by coupling of PEG derivatives. All the reactions were confirmed by ATR FT-IR and ESCA. The degree of ozonation measured by the iodide method was dependent on the ozone permeability of the polymers used. Surface hydrophilicity was investigated by measuring the contact angles. Ozonation itself yielded a slight increase in hydrophilicity and a decrease in platelet adhesion, but PEG immobilization showed a significant effect on surface hydrophilicity and platelet adhesion to confirm well-known PEG's passivity which minimize the adhesion of blood components on polymer surfaces. Both graft polymerization and coupling were effective for PU. In contrast, only grafting gave enough yields for PMMA and silicone. Platelet adhesion results demonstrated that all PEG modified surfaces adsorbed lower platelet adhesion than untreated or ozonated ones. Polymers coupled with sulfonated PEG exhibited the lowest platelet adhesion when compared with control and PEG coupled ones by virtue of the synergistic effect of non-adhesive PEG and negatively charged SO3 groups. This PEG or sulfonated PEG immobilization technology using ozonation is relatively simple for introducing uniform surface modification and therefore very useful for practical application of blood contacting medical devices.

A methodology based on NMR spectroscopy for the forensic analysis of condoms

Both solution and solid state Nuclear Magnetic Resonance (NMR) spectroscopic techniques have been used to determine differences in commercially available condoms. Whilst solid state NMR is useful for determining the polymer backbone, it is not useful for forensic analysis due to the commonality of the latex condom. However solution NMR spectra obtained following a simple extraction procedure using hexane, provides a fingerprint of the additives in the lubricants. Following the development of a flow chart, basing decisions on the presence of particular peaks present in the solution spectra, 33 of 38 condoms could be individualized. Samples were also analyzed after having the lubricant manually removed and soaking the condom in water for 3 to 24 h. These experiments were performed to simulate a case of the sample having been used and disposed of by flushing down the toilet, as may be experienced in a case of a sexual assault. The results indicated that the only significant water soluble component was polyethylene glycol. The overall results suggest that the method developed may be a quick and useful technique in characterizing condoms. The information obtained can be used to provide associative evidence between suspect and crime, and so be useful in sexual assault cases.

RAG transposase can capture and commit to target DNA before or after donor cleavage

The discovery that the V(D)J recombinase functions as a transposase in vitro suggests that transposition by this system might be a potent source of genomic instability. To gain insight into the mechanisms that regulate transposition, we investigated a phenomenon termed target commitment that reflects a functional association between the RAG transposase and the target DNA. We found that the V(D)J recombinase is quite promiscuous, forming productive complexes with target DNA both before and after donor cleavage, and our data indicate that the rate-limiting step for transposition occurs after target capture. Formation of stable target capture complexes depends upon the presence of active-site metal binding residues (the DDE motif), suggesting that active-site amino acids in RAG-1 are critical for target capture. The ability of the RAG transposase to commit to target prior to cleavage may result in a preference for transposition into nearby targets, such as immunoglobulin and T-cell receptor loci. This could bias transposition toward relatively "safe" regions of the genome. A preference for localized transposition may also have influenced the evolution of the antigen receptor loci.

Associations of blood pressure and hypertension with lead dose measures and polymorphisms in the vitamin D receptor and delta-aminolevulinic acid dehydratase genes

Evidence suggests that lead and selected genes known to modify the toxicokinetics of lead--namely, those for the vitamin D receptor (VDR) and delta-aminolevulinic acid dehydratase (ALAD)--may independently influence blood pressure and hypertension risk. We report the relations among ALAD and VDR genotypes, three lead dose measures, and blood pressure and hypertension status in 798 Korean lead workers and 135 controls without occupational exposure to lead. Lead dose was assessed by blood lead, tibia lead measured by X-ray fluorescence, and dimercaptosuccinic acid (DMSA)-chelatable lead. Among lead workers, 9.9% (n = 79) were heterozygous for the ALAD(2) allele, and there were no ALAD(2) homozygotes; 11.2% (n = 89) had at least one copy of the VDR B allele, and 0.5% (n = 4) had the BB genotype. In linear regression models to control for covariates, VDR genotype (BB and Bb vs. bb), blood lead, tibia lead, and DMSA-chelatable lead were all positive predictors of systolic blood pressure. On average, lead workers with the VDR B allele, mainly heterozygotes, had systolic blood pressures that were 2.7-3.7 mm Hg higher than did workers with the bb genotype. VDR genotype was also associated with diastolic blood pressure; on average, lead workers with the VDR B allele had diastolic blood pressures that were 1.9-2.5 mm Hg higher than did lead workers with the VDR bb genotype (p = 0.04). VDR genotype modified the relation of age with systolic blood pressure; compared to lead workers with the VDR bb genotype, workers with the VDR B allele had larger elevations in blood pressure with increasing age. Lead workers with the VDR B allele also had a higher prevalence of hypertension compared to lead workers with the bb genotype [adjusted odds ratio (95% confidence interval) = 2.1 (1.0, 4.4), p = 0.05]. None of the lead biomarkers was associated with diastolic blood pressure, and tibia lead was the only lead dose measure that was a significant predictor of hypertension status. In contrast to VDR, ALAD genotype was not associated with the blood pressure measures and did not modify associations of the lead dose measures with any of the blood pressure measures. To our knowledge, these are the first data to suggest that the common genetic polymorphism in the VDR is associated with blood pressure and hypertension risk. We speculate that the BsmI polymorphism may be in linkage disequilibrium with another functional variant at the VDR locus or with a nearby gene.

Associations of blood pressure and hypertension with lead dose measures and polymorphisms in the vitamin D receptor and delta-aminolevulinic acid dehydratase genes

Evidence suggests that lead and selected genes known to modify the toxicokinetics of lead--namely, those for the vitamin D receptor (VDR) and delta-aminolevulinic acid dehydratase (ALAD)--may independently influence blood pressure and hypertension risk. We report the relations among ALAD and VDR genotypes, three lead dose measures, and blood pressure and hypertension status in 798 Korean lead workers and 135 controls without occupational exposure to lead. Lead dose was assessed by blood lead, tibia lead measured by X-ray fluorescence, and dimercaptosuccinic acid (DMSA)-chelatable lead. Among lead workers, 9.9% (n = 79) were heterozygous for the ALAD(2) allele, and there were no ALAD(2) homozygotes; 11.2% (n = 89) had at least one copy of the VDR B allele, and 0.5% (n = 4) had the BB genotype. In linear regression models to control for covariates, VDR genotype (BB and Bb vs. bb), blood lead, tibia lead, and DMSA-chelatable lead were all positive predictors of systolic blood pressure. On average, lead workers with the VDR B allele, mainly heterozygotes, had systolic blood pressures that were 2.7-3.7 mm Hg higher than did workers with the bb genotype. VDR genotype was also associated with diastolic blood pressure; on average, lead workers with the VDR B allele had diastolic blood pressures that were 1.9-2.5 mm Hg higher than did lead workers with the VDR bb genotype (p = 0.04). VDR genotype modified the relation of age with systolic blood pressure; compared to lead workers with the VDR bb genotype, workers with the VDR B allele had larger elevations in blood pressure with increasing age. Lead workers with the VDR B allele also had a higher prevalence of hypertension compared to lead workers with the bb genotype [adjusted odds ratio (95% confidence interval) = 2.1 (1.0, 4.4), p = 0.05]. None of the lead biomarkers was associated with diastolic blood pressure, and tibia lead was the only lead dose measure that was a significant predictor of hypertension status. In contrast to VDR, ALAD genotype was not associated with the blood pressure measures and did not modify associations of the lead dose measures with any of the blood pressure measures. To our knowledge, these are the first data to suggest that the common genetic polymorphism in the VDR is associated with blood pressure and hypertension risk. We speculate that the BsmI polymorphism may be in linkage disequilibrium with another functional variant at the VDR locus or with a nearby gene.

Associations of blood lead, dimercaptosuccinic acid-chelatable lead, and tibia lead with neurobehavioral test scores in South Korean lead workers

The authors performed a cross-sectional study to evaluate associations between blood lead, tibia lead, and dimercaptosuccinic acid (DMSA)-chelatable lead and measures of neurobehavioral and peripheral nervous system function among 803 lead-exposed workers and 135 unexposed controls in South Korea. The workers and controls were enrolled in the study between October 1997 and August 1999. Central nervous system function was assessed with a modified version of the World Health Organization Neurobehavioral Core Test Battery. Peripheral nervous system function was assessed by measuring pinch and grip strength and peripheral vibration thresholds. After adjustment for covariates, the signs of the beta coefficients for blood lead were negative for 16 of the 19 tests and blood lead was a significant predictor of worse performance on eight tests. On average, for the eight tests that were significantly associated with blood lead levels, an increase in blood lead of 5 microg/dl was equivalent to an increase of 1.05 years in age. In contrast, after adjustment for covariates, tibia lead level was not associated with neurobehavioral test scores. Associations with DMSA-chelatable lead were similar to those for blood lead. In these currently exposed workers, blood lead was a better predictor of neurobehavioral performance than was tibia or DMSA-chelatable lead, mainly in the domains of executive abilities, manual dexterity, and peripheral motor strength.

Predictors of DMSA chelatable lead, tibial lead, and blood lead in 802 Korean lead workers

OBJECTIVES

To examine the interrelations among chelatable lead (by dimercaptosuccinic acid, DMSA), tibial lead, and blood lead concentrations in 802 Korean workers with occupational exposure to lead and 135 employed controls with only environmental exposure to lead.

METHODS

This was a cross sectional study wherein tibial lead, DMSA chelatable lead, and blood lead were measured. Linear regression was used to identify predictors of the three lead biomarkers, evaluating the influence of age, job duration, sex, education level, alcohol and tobacco use, creatinine clearance rate, and body mass index.

RESULTS

DMSA chelatable lead concentrations ranged from 4.8 to 2102.9 microg and were positively associated with age, current smoking, and creatinine clearance rate. On average, women had 64 microg less DMSA chelatable lead than men. When blood lead and its square were added to a model with age, sex, current smoking, body mass index, and creatinine clearance rate, blood lead accounted for the largest proportion of the variance and sex became of borderline significance. Tibial lead concentrations ranged from -7 to 338 microg/g bone mineral and were positively associated with age, job duration, and body mass index. Women had, on average, 9.7 microg/g less tibial lead than men. Blood lead concentrations ranged from 4.3 to 85.7 microg/dl and were positively associated with age and tibial lead, whereas current smokers had higher blood lead concentrations and women had lower blood lead concentrations.

CONCLUSIONS

The data suggest that age and sex are both predictors of DMSA chelatable lead, blood lead, and tibial lead concentrations and that tibial lead stores in older subjects are less bioavailable and may contribute less to blood lead concentrations than tibial lead stores in younger subjects. Although blood lead concentrations accounted for a large proportion of the variance in DMSA chelatable lead concentrations, suggesting that measurement of both in epidemiological studies may not be necessary, the efficacy of each measure in predicting health outcomes in epidemiological studies awaits further investigation.

Effect of the double bond pi-conjugation of the aromatic group of racemic analytes on the liquid chromatographic separation of enantiomers

Various arylcarbinol esters were resolved on a commercial chiral column, (S, S) Whelk-O1. Among others, the analytes in which the aryl group is in conjugation with the double bond(s) to the chiral center were resolved much better on (S, S) Whelk-O1 than the corresponding non-double bonded analytes. From these results, it was proposed that the double bond pi-conjugation of the aromatic group of racemic analytes is very important for the chiral recognition. In addition, the size of the acyl group of arylcarbinol esters has been demonstrated to be important for the chiral recognition. In general, the large acyl group such as pivaloyl group was very effective for the chiral recognition of arylcarbinol esters on (S, S) Whelk-O1.

Structural characterisation of macromolecular organic material in air particulate matter using Py-GC-MS and solid state 13C-NMR

Organic air particulate matter was analysed by applying the techniques of Py-GC-MS (pyrolysis-gas chromatography-mass spectrometry) and solid state 13C-NMR (nuclear magnetic resonance). Particles dislodged from air particulate filters and humic acid extracted from these filters were studied for structural components. The structural components of the air particles and extracted humic acid consisted of compounds originating from biomacromolecules, namely, lignin, carbohydrates, protein and lipids. The main components identified for each class included: (1) methoxyphenols originating from lignin; (2) furans, aldehydes and ketones from carbohydrates; (3) pyrrole, indoles from protein; and (4) many hydrocarbons from lipid structures. Single ion monitoring (SIM) and tetramethyl ammonium hydroxide (TMAH) methylation were utilised for detection of aliphatic hydrocarbons and acidic components, respectively. Hydrocarbons ranging from C9 to C28 were detected by SIM analysis, while aliphatic acids ranged from C9 to C18. The majority of components analysed directly in the air particles were similar to those from the humic acid extracts. Many of the structural components of air particles were typical of humic substances of soil and aqueous systems and these were attributed to both biogenic and anthropogenic sources.

Associations of blood lead, dimercaptosuccinic acid-chelatable lead, and tibia lead with polymorphisms in the vitamin D receptor and [delta]-aminolevulinic acid dehydratase genes

A cross-sectional study was performed to evaluate the influence of polymorphisms in the [delta]-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genes on blood lead, tibia lead, and dimercaptosuccinic acid (DMSA)-chelatable lead levels in 798 lead workers and 135 controls without occupational lead exposure in the Republic of Korea. Tibia lead was assessed with a 30-min measurement by (109)Cd-induced K-shell X-ray fluorescence, and DMSA-chelatable lead was estimated as 4-hr urinary lead excretion after oral administration of 10 mg/kg DMSA. The primary goals of the analysis were to examine blood lead, tibia lead, and DMSA-chelatable lead levels by ALAD and VDR genotypes, controlling for covariates; and to evaluate whether ALAD and VDR genotype modified relations among the different lead biomarkers. There was a wide range of blood lead (4-86 microg/dL), tibia lead (-7-338 microg Pb/g bone mineral), and DMSA-chelatable lead (4.8-2,103 microg) levels among lead workers. Among lead workers, 9.9% (n = 79) were heterozygous for the ALAD(2) allele and there were no homozygotes. For VDR, 10.7% (n = 85) had the Bb genotype, and 0.5% (n = 4) had the BB genotype. Although the ALAD and VDR genes are located on different chromosomes, lead workers homozygous for the ALAD(1) allele were much less likely to have the VDR bb genotype (crude odds ratio = 0.29, 95% exact confidence interval = 0.06-0.91). In adjusted analyses, subjects with the ALAD(2) allele had higher blood lead levels (on average, 2.9 microg/dL, p = 0.07) but no difference in tibia lead levels compared with subjects without the allele. In adjusted analyses, lead workers with the VDR B allele had significantly (p < 0.05) higher blood lead levels (on average, 4.2 microg/dL), chelatable lead levels (on average, 37.3 microg), and tibia lead levels (on average, 6.4 microg/g) than did workers with the VDR bb genotype. The current data confirm past observations that the ALAD gene modifies the toxicokinetics of lead and also provides new evidence that the VDR gene does so as well.

A comparison of different lead biomarkers in their associations with lead-related symptoms

OBJECTIVES

To evaluate whether dimercaptosuccinic acid (DMSA) -chelatable lead, an estimate of current bioavailable lead stores, is a better predictor of lead-related symptoms than are other commonly used lead biomarkers.

METHODS

A total of 95 male lead workers from three lead industries (one secondary lead smelting facility, one polyvinyl chloridestabilizer manufacturing plant, and one lead-acid storage battery factory), and 13 workers without occupational lead exposure recruited from an occupational health institute, were studied. Blood lead, blood zinc protoporphyrin (ZPP), 4 h DMSA-chelatable lead (after oral administration of 10 mg/kg DMSA), urine lead, and urinary delta-aminolevulinic acid levels were evaluated as predictors of 15 lead-related symptoms, assessed by self-administered questionnaire, with linear and logistic regression controlling for covariates. Total symptoms and symptoms in three categories (gastrointestinal, neuromuscular, and general) were evaluated.

RESULTS

The mean (SD) 4 h DMSA-chelatable lead level was 288.7 (167.7) microg, with a range from 32.4 to 789 microg in the 95 lead workers. The mean (SD) in the non-exposed subjects was 23.7 (11.5) microg with a range from 10.5 to 43.5 microg. Blood lead, blood ZPP, and spot urine lead levels ranged from 21.4 to 78.4 microg/dl, 40 to 331 microg/l, and 7.5 to 153.0 micro/l, respectively, in the lead workers, and from 4.0 to 7.2 micro/dl, 27 to 52 microg/l, and 2.9 to 15.5 microg/l in the non-exposed controls, respectively. The overall mean symptom score (SD), derived as the sum of 0 or 1 point for absence or presence of 15 symptoms, of the lead workers was 3.7 (2.0), compared to 1.2 (1.5) for the non-exposed workers. DMSA-chelatable lead was the best predictor of symptom scores in both crude and adjusted analyses, compared with the other biomarkers. Lead workers with DMSA-chelatable lead values greater than the median (260.5 microg) were 6.2 times more likely to have frequent tingling or numbness of the arms or legs and 3.3 times more likely to have muscle pain than subjects with lower chelatable lead values. Three symptoms (tingling or numbness of arm or leg, muscle pain, and feeling irritation at the slightest disturbance) evidenced a dose-dependent relationship with DMSA-chelatable lead levels.

CONCLUSIONS

DMSA-chelatable lead was found to be the best predictor of lead-related symptoms, particularly of both total symptom scores and neuromuscular symptoms, than were the other other lead biomarkers.

High-resolution solid state 13C nuclear magnetic resonance spectra of 3,4-methylenedioxyamphetamine hydrochloride and related compounds and their mixtures with lactose

Differences between solution and solid state 13C nuclear magnetic resonance spectra of some amphetamines namely, 3,4-methylenedioxyamphetamine HCI, (R.S)-MDA HCI, the methyl derivative 3,4-methylenedioxy-N-methylamphetamine x HCI, (R,S)-MDMA x HCI, the ethyl derivative, (R,S)-MDEA x HCI, and the analogues (R,S)-methamphetamine HCI, (-)-ephedrine x HCI (the 3R,2S enantiomer as numbered here), and (+)-pseudo-ephedrine x HCI (the 3S,2S enantiomer as numbered here) have been studied and related to their crystal structure. For (R,S)-MDMA x HCI, an interesting new finding is that the observed solid state chemical shifts changed when lactose monohydrate was added as a dry powder and thoroughly mixed at room temperature. This experiment mimicked the illicit production of "Ecstasy" tablets. The mixing phenomena with lactose observed for (R.S)-MDMA x HCI was not seen for the other compounds studied. The results are discussed in terms of hydrogen bonding and possible polymorphs. It appears that lactose affects crystal packing by reducing conformational rigidity so that the molecule more closely resembles that in solution.

Spatial distribution and sampling plans for Thrips palmi (Thysanoptera: Thripidae) infesting fall potato in Korea

The spatial distribution of adult and immature Thrips palmi Karny on fall potato, Solanum tuberosum L., on Cheju Island, Korea, was studied over a 2-yr period by visually inspecting potato leaves. The majority of thrips collected from the leaves were observed in the top one-third of the plant. The within-field spatial patterns of adults and immature thrips were aggregated. The slopes and intercepts of Taylor's power law did not differ among adults and immature thrips. A fixed-precision-level sampling plan was developed using the parameters from Taylor's power law and was tested with resampling simulations using eight independent data sets. Over a wide range of densities, the simulation demonstrated that actual sampling precision (d = SEM/mean) values at d = 0.25 averaged < 0.24 in all cases. A binomial sampling plan for estimating mean density was developed using an empirical model evaluated at tally thresholds (the minimum number of insects present before a leaf is considered infested) of one, three, five, and eight thrips per leaf. Increasing sampling size had little effect on the precision of the estimated mean regardless of tally threshold (T). However, increasing T had a dramatic effect on precision. The best tally threshold for estimating thrips density based on the applicable density ranges and the precision of the model was T = 5. A binomial sampling plan with a tally threshold of five and a fixed sample size of 30 leaves should be an effective replacement for enumerative counts when thrips average < 10 per leaf.

Identification of a murine locus conveying susceptibility to cadmium-induced forelimb malformations

The heavy metal cadmium (Cd), an environmentally ubiquitous contaminant, is a potent teratogen in mice. When administered parenterally, it induces an array of malformations that vary in scope and severity with the route, dose, time of administration, and the strain of the animal. When administered intraperitoneally on day 9.0 of gestation, 4 mg/kg cadmium chloride produces forelimb defects (predominantly ectrodactyly) in over 80% of fetuses of the C57BL/6 mouse strain, while no limb defects are observed in the identically treated SWV strain. Like other examples of strain-specific teratogenic activity, the underlying nature of the differential susceptibility remains unknown. The present study investigates the segregation of sensitivity to Cd-induced forelimb defects in crosses between C57BL/6 and SWV mice and provides evidence for the involvement of both maternal and fetal factors in the determination of defect expression. In addition, quantitative trait loci (QTL) analysis of the fetal genetic component was performed among 198 backcross progeny, utilizing a genomic linkage map of 149 informative microsatellite markers. One QTL demonstrating significant linkage to expression of the defect, designated Cadfar (cadmium-induced forelimb autopod reduction), was mapped to the distal end of chromosome 6 with a lod score of 3.1.

Is intracytoplasmic sperm injection necessary for couples undergoing in vitro fertilization-embryo transfer with normal semen analyses but failing hamster egg penetration assays?

PURPOSE

Our purpose was to assess whether in vitro fertilization (IVF)-embryo transfer (ET) candidate couples with basically normal semen analyses but failing zona-free hamster egg penetration assay (HEPA) scores benefit from intracytoplasmic sperm injection (ICSI).

METHODS

Twenty consecutive IVF candidate couples with normal-borderline semen analyses and failing HEPA scores were recruited. Mature oocytes obtained from each woman were randomly divided between ICSI (group I; n = 126 oocytes) and standard insemination techniques (group II; 138 oocytes). Fertilization (two pronuclei) and cleavage (2-4 cells) rates were assessed for both groups.

RESULTS

There were no statistically significant differences between the two groups with respect to (mean +/- standard error of the mean) fertilization (group I, 63.1 +/- 7.75; group II, 77.8 +/- 4.7%) or cleavage (group I, 87.3 +/- 2.4%; group II, 91.2 +/- 3.5%) rates.

CONCLUSIONS

ICSI is not beneficial for IVF-ET when sperm samples demonstrate a failing HEPA score but have normal or minimally compromised semen analysis parameters.

Expression of cyclin E in gynecologic malignancies

OBJECTIVE

This study investigated the patterns of expression of cyclin E in clear cell carcinoma and other gynecological cancers.

METHODS

Immunohistochemistry was performed on paraffin-embedded archival specimens of ovarian, endometrial, cervical, and renal carcinomas.

RESULTS

Expression of cyclin E was evident in epithelial ovarian carcinomas utilizing immunohistochemistry. Immunohistochemistry revealed a high level of expression of cyclin E in a subset of gynecologic carcinomas, namely clear cell carcinomas, but not in clear cell carcinomas of renal origin.

CONCLUSION

These data suggest that an elevated level of immunohistochemical activity of cyclin E is a property of clear cell carcinomas of Müllerian origin. Immunohistochemistry with anti-cyclin E antibodies may serve as a useful method for diagnosing gynecologic clear cell carcinomas. Future studies are needed to confirm a possible increased activity of cyclin E in clear cell tumors.

Synthesis and evaluation of 2 beta-oxyimino and alkenylpenicillanic acid sulfone derivatives as beta-lactamase inhibitors

The synthesis and in vitro synergies of 2 beta-alkenyl and oxyiminopenam sulfone derivatives are described. Most of the compounds synthesized exhibited good inhibitory activities and synergistic antibacterial activities with piperacillin and ceftriaxone, respectively, against several beta-lactamase producing strains. Particularly the 2 beta-alkenylpenam sulfone derivatives. 1e and 1g, showed good synergistic activity with ceftriaxone against Citrobacter freundi NIH 10018-68 and Proteus vulgaris 20. Also the compounds 2a, 2c, and 2f, 2 beta-oxyiminopenam sulfone derivatives, exhibited improved synergistic activity with piperacillin against Citrobacter freundi NIH 10018-68.

Prevention and preemptive therapy of postransplant lymphoproliferative disease in pediatric liver recipients

BACKGROUND

We have previously reported a 10% incidence of posttransplant lymphoproliferative disease (PTLD) in pediatric patients receiving first liver grafts and primarily immunosuppressed with tacrolimus. To decrease the incidence of PTLD, we developed a protocol utilizing preemptive intravenous ganciclovir in high-risk recipients (i.e., donor (D)+, recipient (R)-), combined with serial monitoring of peripheral blood for Epstein Barr virus (EBV) by polymerase chain reaction (PCR).

METHODS

Consecutive pediatric recipients of a first liver graft were immunosuppressed with oral tacrolimus (both induction and maintenance), and low-dose prednisone. EBV serologies were obtained at the time of orthotopic liver transplant in recipients and donors. Recipients were divided into groups: group 1, high-risk (D+R-), and group 2, low-risk (D+R+; D-R-; D-R+). In group 1 (high-risk), all patients received a minimum of 100 days of intravenous ganciclovir (6-10 mg/kg/day), while, in group 2 (low-risk), patients received intravenous ganciclovir during their initial hospitalization and then were converted to oral acyclovir (40 mg/kg/day) at discharge. Semiquantitative EBV-PCR determinations were made at 1-2-month intervals. In both groups, patients with an increasing viral copy number by EBV-PCR had tacrolimus levels decreased to 2-5 ng/ml. Tacrolimus was stopped, and intravenous ganciclovir reinstituted for PTLD. A positive EBV-PCR with symptoms, but negative histology, was defined as EBV disease; PTLD was defined as histologic evidence of polyclonal or monoclonal B cell proliferation.

RESULTS

Forty children who had survived greater than 2 months were enrolled. There were 18 children in group 1 (high-risk; mean age of 14+/-15 months and mean follow-up time of 243+/-149 days) and 22 children in group 2 (low-risk; mean age of 64+/-65 months and follow-up time of 275+/-130 days). In group 1 (high-risk), there was no PTLD and one case of EBV disease (mononucleosis-like syndrome), which resolved. In group 2 (low-risk), there were two cases of PTLD; both resolved when tacrolimus was stopped. Both children were 8 months old at time of transplant. Neither received OKT3, and they had one and two episodes of steroid-sensitive rejection, respectively. One child had EBV disease (mild hepatitis), which resolved.

CONCLUSIONS

Since instituting this protocol, the overall incidence of PTLD has fallen from 10% to 5% for children receiving primary tacrolimus therapy after OLT. No high-risk pediatric liver recipient treated preemptively with intravenous ganciclovir developed PTLD. Both children with PTLD were less than 1 year at OLT and considered low-risk. However, their positive EBV antibody titers may have been maternal in origin and not have offered long-term protection. Serial monitoring of EBV-PCR after pediatric OLT is recommended to decrease the risk of PTLD by allowing early detection of EBV infection, which is then managed by decreasing immunosuppression and continuing intravenous ganciclovir.

Practical synthesis of Taxol side chain

Practical large scale synthesis of N-benzoyl-(2R,3S)-phenylisoserine methyl ester of the Taxol side chain has been attained from the coupling of chiral imine of N-[(S)-methylbenzyl]benzaldimine with (Z)-alpha-methoxy trimethylsilyl ketene acetal followed by the sequential reactions of lactamization, demethylation, methanolysis and N-benzoylation.

Differential response of glomerular epithelial and mesangial cells after subtotal nephrectomy

Recent studies in both human and experimental chronic renal disease suggest that there is a linkage between glomerular hypertrophy and glomerulosclerosis. To further define these relationships, we studied the changes in glomerular hypertrophy, procollagen alpha 1(IV) mRNA levels and glomerulosclerosis in rats undergoing 1 2/3 nephrectomy (Nx) or sham nephrectomy (SNx). Glomerular hypertrophy, measured biochemically by RNA/DNA and protein/DNA ratios, was significantly increased in Nx compared to SNx two days after subtotal renal ablation (RNA/DNA: Nx = 133 +/- 8%, SNx = 100 +/- 3% of the mean control value, P < 0.01; protein/DNA: Nx = 164 +/- 22%, SNx = 100 +/- 10%, P < 0.05) and remained elevated after 7 and 15 days (RNA/DNA: seven days Nx = 155 +/- 3%, SNx = 100 +/- 13%, P < 0.01; 15 days Nx = 303 +/- 21%, SNx = 100 +/- 24%, P < 0.001; protein/DNA: seven days Nx = 228 +/- 57%, SNx = 100 +/- 18%, P < 0.05; 15 days Nx = 341 +/- 23%, SNx = 100 +/- 18%, P < 0.01). Light microscopic measures of glomerular tuft volume (GTV) were too insensitive to detect glomerular enlargement until 15 days postoperatively, but GTV measured ultrastructurally demonstrated a 20% increment in Nx compared to SNx as early as two days postoperatively (P < 0.01). The latter increment in GTV was due exclusively to glomerular visceral epithelial cell (GVEC) expansion. Glomerular procollagen alpha 1(IV) mRNA levels were significantly elevated only 15 days after nephrectomy (Nx = 265 +/- 58% of the mean control value, SNx = 100 +/- 12%, P < 0.05; corrected for beta-actin mRNA levels). As this time, exuberant mesangial expansion measured ultrastructurally contributed to a 1.6 +/- 0.1-fold increase in GTV (P < 10(-5)), and to a relative decrement in the GVEC contribution to glomerular cells plus matrix (P < 0.01). Segmental sclerosis was observed only 15 days postoperatively in Nx (Nx = 1.3 +/- 0.4% of glomeruli evaluated, SNx = 0.0%, P < 0.05), and there was a strong correlation between the prevalence of segmental sclerosis and the procollagen alpha 1(IV) mRNA levels in Nx at 15 days (r = 0.93, P < 0.01). There was no significant correlation between the RNA/DNA and protein/DNA ratios and procollagen alpha 1(IV) mRNA levels. Thus, glomerular regions responded differentially to subtotal nephrectomy. Early epithelial cell expansion was followed by later mesangial expansion. Glomerular procollagen alpha 1(IV) mRNA levels were elevated only during the second (mesangial) phase of glomerular hypertrophy, when it correlated with glomerulosclerosis, but not during the initial (epithelial) phase, a pattern consistent with a mesangial origin of the procollagen alpha 1(IV) mRNA.

Corticomedullary procollagen alpha1(IV) mRNA levels and localization after subtotal nephrectomy

The relationships between tubular hypertrophy/hyperplasia, procollagen alpha1(IV) mRNA levels, and the development of tubular basement membrane thickening were studied in male Sprague-Dawley rats subjected to subtotal renal ablation and sacrificed 2 or 15 days later. Tubular hypertrophy and hyperplasia were demonstrable at 2 days, however no increment in procollagen alpha1 (IV) mRNA levels was discerned at that time, demonstrating a dissociation between mRNA levels for classical type IV collagen and tubular enlargement. At 15 days, tubular procollagen alpha1(IV) mRNA levels did increase approximately 2-fold (p < 0.002), localizing predominantly in proximal tubules in the deep cortex and outer medullary stripe. At this time point, there was still no significant correlation to tubular enlargement, but there was a significant correlation to tubular basement membrane thickening (r = 0.89, p < 0.01). These studies demonstrated that an increase in mRNA for classical type IV collagen is not required for the development of hypertrophy, and that the increment is a better marker for matrix expansion than it is for hypertrophy.

Topical reversion at the HIS1 locus of Saccharomyces cerevisiae. A tale of three mutants

Mutants of the HIS1 locus of the yeast Saccharomyces cerevisiae are suitable reporters for spontaneous reversion events because most reversions are topical, that is, within the locus itself. Thirteen mutations of his1-1 now have been identified with respect to base sequence. Revertants of three mutants and their spontaneous reversion rates are presented: (1) a chain termination mutation (his1-208, née his1-1) that does not revert by mutations of tRNA loci and reverts only by intracodonic suppression; (2) a missense mutation (his1-798, née his1-7) that can revert by intragenic suppression by base substitutions of any sort, including a back mutation as well as one three-base deletion; and (3) a -1 frameshift mutation (his1-434, née his1-19) that only reverts topically by +1 back mutation, +1 intragenic suppression, or a -2 deletion. Often the +1 insertion is accompanied by base substitution events at one or both ends of a run of A's. Missense suppressors of his1-798 are either feeders or nonfeeders, and at four different locations within the locus, a single base substitution encoding an amino acid alteration will suffice to turn the nonfeeder phenotype into a feeder phenotype. Late-appearing revertants of his1-798 were found to be slowly growing leaky mutants rather than a manifestation of adaptive mutagenesis. Spontaneous revertants of his1-208 and his1-434 produced no late-arising colonies.