FiehnLib: mass spectral and retention index libraries for metabolomics based on quadrupole and time-of-flight gas chromatography/mass spectrometry

At least two independent parameters are necessary for compound identification in metabolomics. We have compiled 2 212 electron impact mass spectra and retention indices for quadrupole and time-of-flight gas chromatography/mass spectrometry (GC/MS) for over 1000 primary metabolites below 550 Da, covering lipids, amino acids, fatty acids, amines, alcohols, sugars, amino-sugars, sugar alcohols, sugar acids, organic phosphates, hydroxyl acids, aromatics, purines, and sterols as methoximated and trimethylsilylated mass spectra under electron impact ionization. Compounds were selected from different metabolic pathway databases. The structural diversity of the libraries was found to be highly overlapping with metabolites represented in the BioMeta/KEGG pathway database using chemical fingerprints and calculations using Instant-JChem. In total, the FiehnLib libraries comprised 68% more compounds and twice as many spectra with higher spectral diversity than the public Golm Metabolite Database. A range of unique compounds are present in the FiehnLib libraries that are not comprised in the 4345 trimethylsilylated spectra of the commercial NIST05 mass spectral database. The libraries can be used in conjunction with GC/MS software but also support compound identification in the public BinBase metabolomic database that currently comprises 5598 unique mass spectra generated from 19,032 samples covering 279 studies of 47 species (plants, animals, and microorganisms).

FiehnLib: mass spectral and retention index libraries for metabolomics based on quadrupole and time-of-flight gas chromatography/mass spectrometry

At least two independent parameters are necessary for compound identification in metabolomics. We have compiled 2 212 electron impact mass spectra and retention indices for quadrupole and time-of-flight gas chromatography/mass spectrometry (GC/MS) for over 1000 primary metabolites below 550 Da, covering lipids, amino acids, fatty acids, amines, alcohols, sugars, amino-sugars, sugar alcohols, sugar acids, organic phosphates, hydroxyl acids, aromatics, purines, and sterols as methoximated and trimethylsilylated mass spectra under electron impact ionization. Compounds were selected from different metabolic pathway databases. The structural diversity of the libraries was found to be highly overlapping with metabolites represented in the BioMeta/KEGG pathway database using chemical fingerprints and calculations using Instant-JChem. In total, the FiehnLib libraries comprised 68% more compounds and twice as many spectra with higher spectral diversity than the public Golm Metabolite Database. A range of unique compounds are present in the FiehnLib libraries that are not comprised in the 4345 trimethylsilylated spectra of the commercial NIST05 mass spectral database. The libraries can be used in conjunction with GC/MS software but also support compound identification in the public BinBase metabolomic database that currently comprises 5598 unique mass spectra generated from 19,032 samples covering 279 studies of 47 species (plants, animals, and microorganisms).

Regional pattern of white matter microstructural changes in normal aging, MCI, and AD

OBJECTIVE

To cross-sectionally compare the regional white matter fractional anisotropy (FA) of cognitively normal (CN) older individuals and patients with mild cognitive impairment (MCI) and Alzheimer disease (AD), separately focusing on the normal-appearing white matter (NAWM) and white matter hyperintensities (WMH), and to test the independent effects of presumed degenerative and vascular process on FA differences.

METHODS

Forty-seven patients with AD, 73 patients with MCI, and 95 CN subjects received diffusion tensor imaging and vascular risk evaluation. To properly control normal regional variability of FA, we divided cerebral white matter into 4 strata as measured from a series of young healthy individuals (H1 = highest; H2 = intermediate high; H3 = intermediate low; H4 = lowest anisotropy stratum).

RESULTS

For overall cerebral white matter, patients with AD had significantly lower FA than CN individuals or patients with MCI in the regions with higher baseline anisotropy (H1, H2, and H3), corresponding to long corticocortical association fibers, but not in H4, which mostly includes heterogeneously oriented fibers. Vascular risk showed significant independent effects on FA in all strata except H1, which corresponds to the genu and splenium of the corpus callosum. Similar results were found within NAWM. FA in WMH was significantly lower than NAWM across all strata but was not associated with diagnosis or vascular risk.

CONCLUSIONS

Both vascular and Alzheimer disease degenerative process contribute to microstructural injury of cerebral white matter across the spectrum of cognitive ability and have different region-specific injury patterns.

Post-growth annealing effects of Mg doped GaAs epitaxial layers on microstructural and optical properties

The post-growth thermal annealing effects of Mg doped GaAs epitaxial layers on the microstructural and optical properties grown by molecular beam epitaxy (MBE) have been investigated. The properties of Mg doped GaAs are estimated after the process of rapid thermal annealing (RTA) in the temperature range of 600 approximately 750 degrees C. The photoluminescence (PL) peak position of as-grown sample blueshifted from 1.473 to 1.485 eV as well as the pronounced enhancement in PL intensity by annealing at 600 degrees C. In the sample grown at the temperature of T(s) = 475 degrees C, the full-width at half maximum (FWHM) of double crystal X-ray diffraction (DCXRD) decreased form 27 to 8 arcsec with increasing of annealing temperature (600 approximately 700 degrees C). The crystalline quality variation of Mg doped GaAs layers by RTA is greatly dependent upon the doping level.

An overview of lung transplantation in Korea

OBJECTIVE

Lung transplantation (LTx) is the only option for end-stage lung disease refractory to medical treatment. The program was slow to start in Korea; the first LTx was performed in July 1996. By October 2007, 25 lung and 7 heart-lung transplantations have been performed at 5 institutes, with the majority being performed at one center. The aim of this study was to improve the survival rate following LTx by analyzing the operative procedure and its complications.

METHODS

We performed a retrospective review of the medical records of 18 patients who underwent lung and heart-lung transplantations from July 1996 to October 2007 at a single institute. Operative mortality was excluded from the analysis of early and late complications.

RESULTS

There were 12 males and 6 females of mean age 46.2 +/- 11.5 years (range, 25-63 years). The indications for transplantation included pulmonary emphysema (n = 6), idiopathic pulmonary fibrosis (n = 3), lymphangioleiomyomatosis (n = 3), Eisenmenger's syndrome (n = 2), bronchiectasis (n = 2), primary pulmonary hypertension (n = 1), and primary graft dysfunction after a single lung transplantation (SLT; n = 1). Operations consisted of SLTs in 9 patients, bilateral sequential single lung transplantations (BSSLTs) in 8 patients, and a heart-lung transplantation (HLT) in 1 patient. Early complications were bleeding necessitating rethoracotomy, severe reperfusion injury, seizure, prolonged airleak, chylothorax, and pulmonary artery stenosis. Late complications consisted of cytomegalovirus infection, pulmonary tuberculosis, posttransplantation lymphoproliferative disease, gastric ulcer perforation, pneumothorax, chylothorax, empyema, and aspergillosis. There were 5 operative deaths due to intraoperative bleeding (n = 1), acute graft dysfunction (n = 2), and multiorgan failure (n = 2). Excluding the operative mortality, the mean survival period was 18.5 +/- 23.7 months (range, 3-87 months).

CONCLUSIONS

Clinical experience in recent years may have reduced complication rates and led to prolonged survival. Increasing the candidate list through better results and raising awareness of the LTx program is necessary to move forward with thoracic transplantation in Korea.

Spinous process splitting laminectomy for lumbar canal stenosis: a critical appraisal

Spinous process splitting laminectomy (SPSL) is a surgical technique for lumbar canal stenosis, which aims to preserve the paraspinal muscles. Twenty-five patients with lumbar canal stenosis who consecutively underwent SPSL from June 2005 to December 2005 were evaluated. Clinical outcomes were assessed using the visual analogue scale (VAS) scores and Oswestry disability index (ODI). Mean age of the patients at surgery was 62.6 years (range: 42-77 years). Seventeen patients underwent SPSL for single level stenosis, 4 for two levels, and 4 for three levels. In 10 patients, discectomy was simultaneously performed at the same level as SPSL. Of 23 patients (92%) followed for a 1-year period, VAS for back pain, leg pain, and ODI decreased significantly; from 4.8, 8.1, and 54.3-2.1, 2.7, and 23.1, respectively. However, a significant improvement (> 50% of their initial VAS/ODI score) of back pain, leg pain, and functional status was observed in only 65.2, 65.2, and 52.2%, respectively. Complications occurred in 4 patients (16%). Although SPSL for lumbar canal stenosis yielded relatively good clinical outcomes, the percentage of patients showing significant improvements in back pain, leg pain, and functional status were less than expected at one year after surgery.

Refracture after Ilizarov osteosynthesis in atrophic-type congenital pseudarthrosis of the tibia

We investigated patterns of refracture and their risk factors in patients with congenital pseudarthrosis of the tibia after Ilizarov osteosynthesis. We studied 43 cases in 23 patients. Temporal and spatial patterns of refracture and refracture-free survival were analysed in each case. The refracture-free rate of cumulative survival was 47% at five years and did not change thereafter. Refracture occurred at the previous pseudarthrosis in 16 of 19 cases of refracture. The risk of refracture was significantly higher when osteosynthesis was performed below the age of four years, when the tibial cross-sectional area was narrow, and when associated with persistent fibular pseudarthrosis. Refracture occurs frequently after successful osteosynthesis in these patients. Delaying osteosynthesis, maximising the tibial cross-sectional area and stabilising the fibula may reduce the risk of refracture.

The Severe Cognitive Impairment Rating Scale--an instrument for the assessment of cognition in moderate to severe dementia patients

BACKGROUND/AIMS

This study aimed to develop a brief, reliable and valid test for cognitive function of severely demented patients.

METHODS

We constructed the Severe Cognitive Impairment Rating Scale, which consisted of 11 items covering memory, language, visuospatial function, frontal function and orientation, and investigated its reliability and validity on 267 subjects [normal: 65, very mild Alzheimer's disease (AD): 42, mild AD: 58, moderate AD: 36, severe AD: 44, profound AD: 22].

RESULTS

The internal consistency obtained by Cronbach's coefficient alpha was 0.93. The interrater reliability and test-retest reliability in the moderately to severely impaired subjects with an MMSE score of <or=14 was 0.99 (p < 0.001) and 0.90 (p < 0.001), respectively. It showed significant correlation with Severe MMSE (r = 0.96, p < 0.01), MMSE (r = 0.86, p < 0.01) and Clinical Dementia Rating (r = -0.83, p < 0.01). It was robust to both the floor effect in the severe/profound stage of AD and the ceiling effect in the mild/moderate stage of AD. Exploratory factor analysis yielded 2 factors (automatic informational processing and controlled informational processing) accounting for 73.5% of the total variance.

CONCLUSIONS

The Severe Cognitive Impairment Rating Scale is a valid and reliable test for evaluating the cognitive function of advanced AD patients.

High quality metabolomic data for Chlamydomonas reinhardtii

The green eukaryote alga Chlamydomonas reinhardtii is a unicellular model to study control of metabolism in a photosynthetic organism. We here present method improvements for metabolite profiling based on GC-TOF mass spectrometry focusing on three parameters: quenching and cell disruption, extract solvent composition and metabolite annotation. These improvements facilitate using smaller cell numbers and hence, smaller culture volumes which enable faster and more precise sampling techniques that eventually lead to a higher number of samples that can be processed, e.g. for time course experiments. Quenching of metabolism was achieved by mixing 1 ml of culture to 1 ml of -70 degrees C cold 70% methanol. After centrifugation, cells were lyophilized and disrupted by milling using 2-6E6 lyophilized cells, around 500-fold less than previously reported. Glass beads were compared to metal balls for milling, and five different extraction solvents were tested. Additionally, all peaks were annotated in an automated way using the GC-TOF database BinBase instead of manual investigation of a single reference chromatogram. Median precision of analysis was used to decide for the eventual procedure which was applied to a proof-of-principle study of time dependent changes of metabolism under standard conditions.

Quality control for plant metabolomics: reporting MSI-compliant studies

The Metabolomics Standards Initiative (MSI) has recently released documents describing minimum parameters for reporting metabolomics experiments, in order to validate metabolomic studies and to facilitate data exchange. The reporting parameters encompassed by MSI include the biological study design, sample preparation, data acquisition, data processing, data analysis and interpretation relative to the biological hypotheses being evaluated. Herein we exemplify how such metadata can be reported by using a small case study - the metabolite profiling by GC-TOF mass spectrometry of Arabidopsis thaliana leaves from a knockout allele of the gene At1g08510 in the Wassilewskija ecotype. Pitfalls in quality control are highlighted that can invalidate results even if MSI reporting standards are fulfilled, including reliable compound identification and integration of unknown metabolites. Standardized data processing methods are proposed for consistent data storage and dissemination via databases.

A normative study of the Revised Hasegawa Dementia Scale: comparison of demographic influences between the Revised Hasegawa Dementia Scale and the Mini-Mental Status Examination

BACKGROUND/AIMS

We investigated the demographic influence on the performance of the Revised Hasegawa Dementia Scale (HDS-R) and provided normative data of the HDS-R in the elderly.

METHODS

The HDS-R was administered to 803 community-dwelling cognitively normal elderly subjects aged 55 years or over. Cognitive disorders and psychiatric disorders were strictly excluded using the CERAD-K assessment packet and the Mini-International Neuropsychiatric Interview. The demographic influence on the performance of the HDS-R was examined using multiple linear regression analyses, and compared with that on the performance of the Mini-Mental Status Examination (MMSE) using the Chow test and t statistics. Overlapping strata were used in developing age-, education- and gender-specific normative data of the HDS-R.

RESULTS

Age, education, and gender influenced significantly the performance of the HDS-R, and explained 22.5% of the total score variance. Older age, lower education, and male gender were associated with lower performance of the HDS-R. However, the demographic influence on the HDS-R was much weaker than that on the MMSE (t = 5.578, d.f. = 800, p < 0.001). The normative data of the HDS-R stratified by age (60-69, 70-79, > or =80), education (0-6, 7-12, > or =13), and gender were presented.

CONCLUSIONS

The HDS-R was more robust to demographic influences than the MMSE, and normative data may contribute to improving further its diagnostic accuracy for dementia.

Depression in vascular dementia is quantitatively and qualitatively different from depression in Alzheimer's disease

BACKGROUND/AIMS

To compare the prevalence and characteristics of depression in vascular dementia (VaD) and Alzheimer's disease (AD) after adjusting for dementia severity and gender.

METHODS

One hundred and eight pairs of VaD and AD patients matched for dementia severity and gender were assessed.

RESULTS

Major depressive disorder (MDD) was more prevalent in the VaD group than in the AD group (20.4% in VaD, 10.2% in AD, p = 0.04, Cochran-Mantel-Haenszel, CMH, test) regardless of the dementia severity and gender. The odds ratio for developing MDD in the VaD group versus the AD group was estimated to be 2.20 (95% confidence interval = 1.02-4.74). Neurovegetative symptoms such as 'felt tired and weak all the time' (30.6% in VaD, 13.9% in AD, p = 0.003, CMH test) and 'changed weight without trying' (16.7% in VaD, 6.5% in AD, p = 0.02, CMH test) were more prevalent in the VaD group than in the AD group.

CONCLUSION

Depression in VaD was quantitatively and qualitatively different from that in AD regardless of the severity of dementia and gender; depression was more prevalent, severer and more retarded and vegetative in VaD than in AD.

Novel Approach to Performing Metabolite Identification in Drug Metabolism

A novel online method is developed, using liquid chromatography (LC)-accurate radioisotope counting dynamic-flow (ARC) coupled with a radioactivity detector and mass spectrometer, for metabolite identification in drug discovery and development. This method offers the advantages of improved sensitivity for detecting radiolabeled drugs as well as streamlining the process of identifying and characterizing metabolites. For the purposes of evaluating this method, in vitro human liver microsomal incubations with [(14)C]dextromethorphan are conducted. Online separation and identification of [(14)C]dextromethorphan metabolites are achieved without intensive sample preparation, concentration, or fraction collection. Mass spectrometric analysis identified and characterized the metabolites of dextromethorphan formed by N - and O -dealkylation, correlated well with previously published results. Chromatographic peaks for [(14)C]dextromethorphan and its metabolites are collected online, then infused for extended periods of time at a flow rate of 10 microL/min while maintaining the column pressure. The continuous analytical signal input allowed acquisition of a higher order of multistage fragmentation for both major and minor metabolites. The multistage MS fragmentation pattern obtained for the metabolites allowed defining the sites of metabolism for dextromethorphan. Further evaluations of this method are also conducted using a [(14)C]compound A to check the linearity and sensitivity of the dynamic-flow method. The R(2) value is 0.996 for the dynamic-flow method between 50 and 600 disintegrations per minute (dpm); the limit of detection for LC-ARC is 20 dpm, which is approximately 10 times more sensitive than conventional continuous-flow radioactivity detection techniques. The overall results suggest that the combination of LC-ARC with radioactivity detection and mass spectrometry has great potential as a powerful tool for enhancing the sensitivity of radioisotope measurement in metabolite identification studies during drug discovery and development.

Amphiphilic triblock copolymer poly(p-dioxanone-co-L-lactide)-block-poly(ethylene glycol), enhancement of gene expression and inhibition of lung metastasis by aerosol delivery

We describe the development of an aerosol system for topical gene delivery to the lungs of C57BL/6 mice. This system is based on the combination of the commercial cationic lipid Lipofectin with a novel amphiphilic triblock copolymer, poly(p-dioxanone-co-L-lactide)-block-poly(ethylene glycol) (PPDO/PLLA-b-PEG, and abbreviated in the text as polymeric micelles). After optimizing conditions for DNA delivery to the lungs of mice using the combination of polymeric micelles with Lipofectin and LacZ DNA, we used the Lipofectin/polymeric micelle system to deliver the tumor suppressor gene PTEN to the lungs of C57BL/6 mice bearing the B16-F10 melanoma. Lipofectin/PTEN/polymeric micelles significantly improved gene expression of PTEN in the lungs of mice with no evidence of cell toxicity or acute inflammation. Importantly, lung metastasis, as measured by lung weight, was significantly reduced (P<0.001), as were total tumor foci in the lungs (P<0.001) and size of individual tumor nodules in animals treated with Lipofectin/PTEN/polymeric micelles compared with control animals. Survival time was also extended. These results suggest that the Lipofectin/polymeric micelle system is appropriate for enhancing gene delivery in vivo and that it can be applied as a non-invasive gene therapy for lung cancer.

Minimization of immunosuppressive therapy after islet transplantation: combined action of heme oxygenase-1 and PEGylation to islet

We previously established a type of PEGylated islets to attenuate cellular immune reactions by immobilizing polyethylene glycol (PEG) molecules on islet surfaces, thereby synergistically reducing the dose of immunosuppressant cyclosporine A (CsA; 3 mg/kg/day) to protect transplanted islets. However, higher doses of immunosuppressants should be administered after islet transplantation due to nonspecific inflammation. This study documents that PEGylated islets can be cooperatively protected by the systemic overexpression of heme oxygenase-1 (HO-1), which has a potent cytoprotective function in preventing nonspecific inflammation during an early stage following islet transplantation. Under this scheme, the viability of PEGylated islets was improved; that is, PEG molecules could block cellular immunity and HO-1 could exert its cytoprotective property against inflammation. Interestingly, when employed with a low dose of CsA (1 mg/kg/day), a cooperative action of PEG molecules and HO-1 in immune reactions could result in the complete survival of transplanted islets for 100 days without islet function impairment. However, unmodified islets (control) were completely rejected within 2 weeks despite cotreatment with HO-1 expression and CsA. These results demonstrated that the combinatorial protocol of initial induction of HO-1 expression, followed by the daily administration of a low dose CsA after transplantation of PEGylated islets can be employed as a successful cell therapy in clinical islet transplantation.

The influence of facet tropism on herniation of the lumbar disc in adolescents and adults

We carried out a study to determine the effect of facet tropism on the development of adolescent and adult herniation of the lumbar disc. We assessed 149 levels in 140 adolescents aged between 13 and 18 years and 119 levels in 111 adults aged between 40 and 49 years with herniation. The facet tropism of each patient was measured at the level of the herniated disc by CT. There was no significant difference in facet tropism between the herniated and the normal discs in both the adolescent and adult groups, except at the L4-L5 level in the adults. Facet tropism did not influence the development of herniation of the lumbar disc in either adolescents or adults.

Tob is a potential marker gene for the basal layer of the epidermis and is stably expressed in human primary keratinocytes

BACKGROUND

Epidermis consists of multiple layers, from the proliferating basal layer to terminal differentiated cornified layers, and these layers are defined by differentiation status. Tob gene product is known to be a member of the BTG antiproliferative protein family. We investigated the expression pattern of Tob gene product to understand the possible role in differentiation of keratinocytes and epidermis.

OBJECTIVES

In this study, we examined the expression of Tob gene product in the primary cultured human keratinocytes and in the in vivo epidermis.

METHODS

The expression of Tob gene product was assessed by Western blotting analysis. Cellular localization of Tob was detected using the green fluorescent protein-tagged Tob cDNA expression construct. In vivo expression of Tob gene product in the epidermis was determined by immunohistochemistry with paraffin sections.

RESULTS

Tob family members are degraded by the ubiquitine-proteasome system triggered by the growth signal. Tob is stably and abundantly expressed in primary cultured human keratinocytes. Furthermore, the expression of Tob in the keratinocytes persists during the differentiation induced by calcium; however, it was not detected in primary cultured fibroblasts. Also, the subcellular localization of Tob is mainly in the cellular membrane in the primary human keratinocytes. We evaluated Tob expression in normal skin, oral mucosa and different diseases, such as psoriasis, X-linked ichthyosis and squamous cell carcinoma (SCC). Using immunohistochemical analysis, we observed that Tob was selectively expressed in the basal layer of X-linked ichythyosis and the hyperproliferative basal layer of psoriasis and oral mucosa as well as in normal epidermis. In SCC, the expression of Tob gene product was relatively decreased.

CONCLUSIONS

Tob is stably expressed in primary human keratinocytes and it is specifically expressed in the basal layer of in vivo epidermis.

Neuroprotective role of microglia expressing interleukin-4

Little is known about the underlying mechanisms responsible for the death of activated microglia and the functional consequences of the death of these cells, especially in vivo. We show here that intracortical injection of lipopolysaccharide (LPS) led to upregulation of interleukin-4 (IL-4) immunoreactivity, followed by a substantial loss of microglia 3 days later, as visualized by complement receptor type 3 (OX-42) immunostaining and tomato lectin staining. Cells positive for caspase-3 and terminal deoxynucleotidyl transferase mediated fluorescein-dUTP nick-end labeling (TUNEL) were also localized within LPS-activated microglia. IL-4 immunoreactivity was detected as early as 12 hr post-LPS, disappearing at 72 hr. Surprisingly, IL-4 immunoreactivity was detected exclusively in microglia, but not in astrocytes or neurons. In addition, IL-4-neutralizing antibodies markedly increased the survival of activated microglia at 3 days post-LPS. The expression of inducible nitric oxide synthase (iNOS) and tumor-necrosis factor (TNF)-alpha was sustained in parallel in activated microglia, consequently increasing neuronal cell death. To our knowledge, this study is the first to show the endogenous expression of IL-4 in LPS-activated microglia in vivo. Our findings suggest that IL-4 may regulate brain inflammation by inducing the death of activated microglia in vivo and increasing neuronal survival.

Diagnostic accuracy of mini-mental status examination and revised hasegawa dementia scale for Alzheimer's disease

To compare the diagnostic accuracies of the Revised Hasegawa Dementia Scale (HDS-R) and Mini-Mental Status Examination (MMSE) for Alzheimer's diseases (AD), we administered them simultaneously to 82 AD patients and 82 age- and sex-matched nondemented control subjects. The area under the receiver operator curve (AUC) for AD of the HDS-R (AUC(HDS-R)) and MMSE (AUC(MMSE)) were bigger than 0.90 indicating that both tests are useful for detecting AD. However, AUC(HDS-R) (0.952) was significantly larger than that of the AUC(MMSE )(0.902) regardless of the educational level of the subjects, indicating that the HDS-R is more accurate than MMSE in diagnosing AD. Moreover, the superiority of the HDS-R (AUC(HDS-R) = 0.894) to the MMSE (AUC(MMSE) = 0.704) remained significant in mild AD patients alone, who are the focus of screening. In conclusion, the HDS-R is better than the MMSE as a screening instrument for AD.

The study on photoreflectance characteristic of semi-insulating GaAs surface region by its exposure to 6 MeV electron beam

Photoreflectance measurements were performed to investigate the optical properties in the electron beam irradiation semi-insulating GaAs(e-beam irradiation GaAs) and semi-insulating GaAs(SI-GaAs). A considerable increase of the PR amplitudes has been registered after the e-beam irradiation in comparison with the GaAs. It is that result of a higher electron scattering on the lattice defects created by the e-beam.

A new drug carrier, Nalpha-deoxycholyl-L: -lysyl-methylester, for enhancing insulin absorption in the intestine

AIMS/HYPOTHESIS

The development of an orally active insulin formulation will offer great advantages over conventional injectable insulin therapy in the treatment of patients with diabetes mellitus. Since insulin absorption in the intestine is restricted by the natural physiological characteristics of insulin, we developed a small synthetic compound, Nalpha-deoxycholyl-L: -lysyl-methylester (DCK), as an insulin carrier to enhance oral delivery.

METHODS

Streptozotocin-induced diabetic rats orally received single doses of insulin (42 U/kg) or insulin/DCK formulation (10, 21, 30 and 42 U/kg) under fasting conditions. Blood glucose levels and plasma insulin concentrations were measured for 6 h following the administration of the agents. An OGTT was also performed immediately after the administration of the oral insulin/DCK formulation.

RESULTS

The administration of 21, 30 and 42 U/kg (based on insulin activity) of insulin/DCK formulation reduced plasma glucose levels by up to 33.0% (median; range 30.6-70.2%), 78.5% (39.4-86.8%) and 75.2% (67.0-87.4%), respectively, compared with baseline levels. Furthermore, plasma insulin concentrations were observed to rapidly increase. In the OGTT, the insulin/DCK formulation reduced the AUC0-240 for glucose by 30.8% (22.3-54.9%) (p<0.01), and stabilized glycaemia for up to 4 h.

CONCLUSIONS/INTERPRETATION

The results of this study demonstrate that the insulin/DCK formulation can be absorbed in the intestine and that it is biologically efficacious. We therefore suggest that this oral formulation could be used as an alternative to injectable insulin with enhanced clinical effects.

Liquid Chromatography-Accurate Radioisotope Counting and Microplate Scintillation Counter Technologies in Drug Metabolism Studies

The present study involves an analysis of the performance of liquid chromatography (LC)-accurate radioisotope counting (ARC) and microplate scintillation counter (TopCount) technologies in drug metabolism studies. For the purpose of evaluating these systems, biological samples resulting from the metabolism of a radiolabeled [14C] compound, known as compound B, are analyzed using LC-ARC and TopCount under similar high-performance LC conditions. Counting efficiency is 83% for LC-ARC, 77% for TopCount, and linearity is R2 of 0.9998 versus 0.9984, respectively. The limit of detection for LC-ARC is 12 disintegrations per minute (dpm) with 1-min/fraction counting, yet for TopCount it is 8.7 dpm with 5-min/fraction counting. Under optimal conditions for each, the total run time of LC-ARC is approximately half that of TopCount. These results indicate that there is no significant difference between these two systems in terms of efficiency, linearity, and limit of detection. However, the LC-ARC system does not involve any manual operations, yet TopCount requires manual sample transfer and data import. This study shows that impressive progress has been made in the technology of radioisotope counting in drug metabolism using LC-ARC. This system enhances the resolution of radiochromatograms and is able to measure volatile metabolites that TopCount cannot detect at all. The ability to acquire mass spectra online is also a major advancement. The overall results suggest that the combination of LC-ARC with radioactivity detection and mass spectrometry has great potential as a powerful tool for radioisotope measurement in metabolite identification studies during drug discovery and development.

Quantitative Analysis of Interleukin-6 Expression in Porcine Spleen Cells and Alveolar Macrophages using Real-Time PCR

Interleukin-6 (IL-6), a multifocal cytokine produced by lymphoid and non-lymphoid cells, regulates immune responses, acute-phase reactions against bacterial infections, and haematopoiesis. After cloning and sequencing of porcine IL-6, the expression pattern of porcine IL-6 mRNA was evaluated through real-time RT-PCR using porcine immune cells (spleen cells and alveolar macrophages) following stimulation with LPS. The sequence has been reported to GenBank with Accession no. AF 518322. The nucleotide sequence was different at the 89th and 205th positions in comparison with M80258, but only at the 205th with M86722. Comparison of porcine IL-6, Accession no. AF 518322, with IL-6 of human, canine, ovine, and mouse showed homologies of 78%, 81%, 82% and 73% in nucleotide sequence and 42%, 69%, 61% and 42% in amino acids. Expression of IL-6 mRNA was induced by stimulation with LPS. IL-6 mRNA expression in alveolar macrophages peaked at 2 h and decreased sharply to control levels at 4 h, whereas it peaked at 14 h and decreased at 24 h in spleen cells after stimulation with LPS (1 microg/ml). These results suggest that IL-6 mRNA expression in porcine immune cells is cell-type specific and the results of this study could be used as the basis for research on the porcine immune system.

Uterine artery embolization for adenomyosis without fibroids

AIM

To evaluate the potential usefulness of transcatheter uterine artery embolization as a treatment for symptomatic adenomyosis in patients without uterine fibroids.

MATERIALS AND METHODS

Uterine artery embolization using polyvinyl alcohol particles sized 250-710 mm was performed in 43 patients (mean; 40.3 years, range; 31-52 years) with dysmenorrhoea, menorrhagia, or bulk-related symptoms (pelvic heaviness, urinary frequency) due to adenomyosis without fibroids. All patients underwent pre-procedural and 3.5 months (range 1-8 months) follow-up magnetic resonance imaging (MRI) with contrast enhancement. Clinical symptoms were also assessed at the time of MRI before and after embolization.

RESULTS

Significant improvement of dysmenorrhoea (95.2%) and menorrhagia (95.0%) was reported in most patients. Contrast-enhanced MRI revealed non-enhancing areas suggesting coagulation necrosis of adenomyosis in 31 patients (72.1%), decreased size without necrosis in 11 patients (25.6%), and no change in one patient (2.3%). The mean volume reduction of the uteri after uterine artery embolization was 32.5% (from 321.7+/-142.9 to 216.7+/-130.1 cm(3)).

CONCLUSION

Transcatheter uterine artery embolization is an effective therapy for the treatment of symptomatic pure adenomyosis, and may be a valuable alternative to hysterectomy.