Homozygous VN (677C to T) and d/D (2756G to A) variants in the methylenetetrahydrofolate and methionine synthase genes in a case of hyperhomocysteinemia with stroke at young age

Hyperhomocysteinemia is known to be associated with an increased risk of myocardial infarction, stroke, peripheral arterial disease, and venous thrombosis. Gene polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MS) may account for reduced enzyme activity and hyperhomocysteinemia. A recent study has documented evidence of polygenic regulation of plasma homocyteine. We report here on a case of occlusive stroke at young age and hyperhomocysteinemia with homozygous VN (677C to T) variant in the MTHFR gene as well as homozygous D/D (2756G to A) variant in the MS gene.

Molecular genetic analysis of reovirus isolated in Korea

Reovirus isolates from human, striped-field mouse (Apodemus agrarius) and Korean field mouse (A. peninsulae) in Korea showed extensive variability in the patterns of electrophoretic migration of the double-stranded RNA (dsRNA) genome segments. Hemagglutination inhibition (HI) test was performed for serotype determination of 12 reovirus isolates. To clarify genetic diversity and molecular phylogeny of Korean reoviruses, L1, S3 and S4 genomic segments of reoviruses were amplified by RT-PCR and directly sequenced. Among 12 reovirus strains, 9 strains were type 3 and 3 strains were type 2. The L1 was highly conserved showing 91.5-100%, 94.7-100% similarities among Korean isolates, and 77.5-97.9%, 92.6-96.8% similarities compared to other reference strains of each genotypes at nucleotide and amino acid levels, respectively. In S3 and S4 segments, 84.4-99.3%, 72.3-99% nucleotide sequence similarities and 92-99.3%, 89.1-98.4% amino acid sequence similarities among Korean isolates were observed, and 70.8-93.9%, 72.3-98.7% nucleotide sequence similarities and 81.8-100%, 88.3-97.7% amino acid sequence similarities compared with other reference strains of each genotype were observed, respectively. Phylogenetic analyses based on the S3 and S4 nucleotide sequences indicate that genotypes of reovirus are more related with geographic differences rather than host species or date of isolation.

Unsupervised learning from complex data: the matrix incision tree algorithm

Analysis of large-scale gene expression data requires novel methods for knowledge discovery and predictive model building as well as clustering. Organizing data into meaningful structures is one of the most fundamental modes of learning. DNA microarray data set can be viewed as a set of mutually associated genes in a high-dimensional space. This paper describes a novel method to organize a complex high-dimensional space into successive lower-dimensional spaces based on the geometric properties of the data structure in the absence of a priori knowledge. The matrix incision tree algorithm reveals the hierarchical structural organization of observed data by determining the successive hyperplanes that 'optimally' separate the data hyperspace. The algorithm was tested against published data sets yielding promising results.

Mapping the ligand-binding region of Borrelia burgdorferi fibronectin-binding protein BBK32

The cellular attachment and entry of pathogenic microorganisms can be facilitated by the expression of microbial adhesins that bind fibronectin. We have previously described a Borrelia burgdorferi gene, bbk32, that encodes a 47-kDa fibronectin-binding protein. In this study, the ligand-binding region of BBK32 from B. burgdorferi isolate B31 was localized to 32 amino acids. The bbk32 gene was cloned and sequenced from three additional B. burgdorferi isolates representing different genospecies of B. burgdorferi sensu lato. All four bbk32 genes encoded proteins having fibronectin-binding activity when expressed in Escherichia coli, and the deduced proteins shared 81 to 91% amino acid sequence identity within the ligand-binding domain. In addition, the ligand-binding region of BBK32 was found to share sequence homology with a fibronectin-binding peptide defined for protein F1 of Streptococcus pyogenes. The structural and functional similarity between the ligand-binding region of BBK32 and the UR region of protein F1 suggests a common mechanism of cellular adhesion and entry for B. burgdorferi and S. pyogenes.

Generation of enterococci bacteria in a coastal saltwater marsh and its impact on surf zone water quality

Elevated levels of enterococci bacteria, an indicator of fecal pollution, are routinely detected in the surf zone at Huntington State and City Beaches in southern California. A multidisciplinary study was carried out to identify sources of enterococci bacteria landward of the coastline. We find that enterococci bacteria are present at high concentrations in urban runoff, bird feces, marsh sediments, and on marine vegetation. Surprisingly, urban runoff appears to have relatively little impact on surf zone water quality because of the long time required for this water to travel from its source to the ocean. On the other hand, enterococci bacteria generated in a tidal saltwater marsh located near the beach significantly impact surf zone water quality. This study identifies a potential tradeoff between restoring coastal wetlands and protecting beach water quality and calls into question the use of ocean bathing water standards based on enterococci at locations near coastal wetlands.

Genetic analysis of a new mouse model for non-insulin-dependent diabetes

The TallyHo (TH) mouse strain is a newly established model for non-insulin-dependent diabetes mellitus (NIDDM). TH mice show obesity, hyperinsulinemia, hyperlipidemia, and male-limited hyperglycemia. A genetic dissection of the diabetes syndrome has been carried out using male backcross 1 progeny obtained from crosses between (C57BL/6J x TH)F1 and TH mice or (CAST/Ei x TH)F1 and TH mice. A genome-wide scan reveals three quantitative trait loci (QTLs), Tanidd1-3 (TH-associated NIDDM) linked to hyperglycemia. The major QTL (common in both crosses), Tanidd1, maps to chromosome (Chr) 19. Additionally, gene-gene interactions contributing to hyperglycemia have been observed between Tanidd1 and a locus on Chr 18 as well as between Tanidd2 and a locus on Chr 16. The overt hyperglycemia in TH mice is, therefore, likely due to a mutation in a major diabetes susceptibility locus on Chr 19, which interacts with additional genes to lead to an observable phenotype.

First measurement of the low- x, low- Q(2) structure function F(2) in neutrino scattering

A new structure function analysis of CCFR deep inelastic nu-N and nu-N scattering data is presented for previously unexplored kinematic regions down to Bjorken x = 0.0045 and Q(2) = 0.3 GeV(2). Comparisons to charged lepton scattering data from NMC and E665 experiments are made and the behavior of the structure function F(2)(nu)2 is studied in the limit Q(2)-->0.

Pathogenic significance of neuronal migration disorders in temporal lobe epilepsy

To assess the epileptogenic lesions, a series of 202 cases with temporal lobectomy were analyzed histopathologically. The severity of hippocampal neuronal loss in patients with temporal lobe epilepsy was quantitatively analyzed and compared against autopsy controls of patients who died of nonneurologic disorders. For the histopathologic diagnosis of neuronal migration disorder (NMD), immunohistochemical stains for neurofilament protein (NF-M/H) and microtubule-associated protein 2 (MAP2) and Bielschowsky silver stains were routinely performed. Histopathology of NMD was classified by the 4-grade system. MAP2 immunoreactivity was useful in the identification of loss of normal polarization of dendrites in the abnormal neurons. NF-M/H immunohistochemistry and silver stains effectively labeled microscopic or occult lesions of NMD (grade II and III). Ammon hom sclerosis (AHS) was identified in 73.3% and NMD in 57.9%. There was more than 50% neuronal cell loss in 82.8% of AHS, and variable degrees of cell loss were observed in the dual-pathology groups. The frequency of dual pathology (both AHS and NMD) was 65.0% and showed relatively equal distributions in grades I, II, III, whereas the pure NMD group were classified predominantly as grades II and III. NMD might be a basic pathogenic substrate causing temporal lobe epilepsy. The dual pathology may indicate the presence of epileptogenic lesions in the neocortical and temporolimbic areas.

Binding and regulation of HIF-1alpha by a subunit of the proteasome complex, PSMA7

The hypoxia-inducible factor-1alpha (HIF-1alpha) is an important transcription factor for cellular responses to oxygen tension. It is rapidly degraded under normoxic conditions by the ubiquitin-dependent proteasome pathway. Here we report a critical role of the 20S proteasome subunit PSMA7 in HIF-1alpha regulation. PSMA7 was found to interact specifically with two subdomains of HIF-1alpha. PSMA7 inhibited the transactivation function of HIF-1alpha under both normoxic and hypoxia-mimicking conditions. In addition, we show that the PSMA7-mediated regulation of HIF-1alpha activity is associated with the proteasome pathway.

Does Umbilical Vein Catheterization Lead to Portal Venous Thrombosis? Prospective US Evaluation in 100 Neonates

PURPOSE

To establish, by means of serial ultrasonography (US), the incidence and natural history of neonatal portal venous thrombosis associated with catheterization of the umbilical vein and to evaluate the potential risk factors predisposing patients to thrombus formation.

MATERIALS AND METHODS

Neonates who had undergone umbilical vein catheterization were studied. US was performed at 2-7-day intervals, before and after the removal of the catheter, until clot resolution or hospital discharge. The presence of portal venous thrombosis and temporal evolution were noted, and various risk factors were analyzed.

RESULTS

US demonstrated clinically silent portal venous thrombosis in 43 (43%) of 100 neonates. Follow-up US revealed complete or partial resolution in 20 (56%) of 36 babies. A significant (P =.024) correlation was found between the initial size of the thrombi and spontaneous clot resolution. Statistically significant risk factors were catheterization for more than 6 days (P =.001) and transfusion (P =.019).

CONCLUSION

Portal venous thrombosis is frequently associated with the placement of an umbilical venous catheter, and spontaneous resolution is expected in many cases. The duration of catheter placement should be minimized, and US monitoring is recommended as a guide to catheter removal.

Comparative analysis of texture characteristics of malignant and benign tumors in breast ultrasonograms

We evaluated various texture features and region of interest (ROI) types of breast ultrasonograms in order to determine the best-performing combinations for differentiating between benign and malignant solid breast nodules. A total of 21 breast ultrasonograms (12 benign, nine malignant) containing solid breast nodules were evaluated. Eight ROI types were defined around the nodules. The texture feature of each ROI was measured and the ratios of texture features were calculated for each pair of ROIs. This procedure was repeated for five different feature types, thus yielding texture feature ratios for 140 different combinations of ROIs and texture features. We evaluated the performance of the texture feature ratio in differentiating between benign and malignant nodules using t test analysis. Evaluating the top ranked texture and ROI combinations, we found edge density and mutual information were the best two texture features, and that the ROI types of outside lesion and lesion margin had good performance.

p53 Codon 72 Polymorphism and Cervical Adenocarcinoma Risk in Korean Women

PURPOSE

This study was undertaken to analyze whether the p53 codon 72 single nucleotide polymorphism might be correlated with the risk and/or the prognosis of cervical cancer in Korean women.

MATERIALS AND METHODS

Peripheral blood samples derived from patients with cervical squamous cell carcinoma (SCC) (n=68), cervical adenocarcinoma (n=37), cervical intraepithelial neoplasia (CIN) III (n=98) and normal controls (n=98) were examined. Germline genomic DNA was extracted from peripheral blood leukocytes and examined by PCR amplification of the specific alleles assay described by Storey et al.5 Statistical analysis was performed using the Chi-Square test or the Kaplan-Meier survival analysis, logistic regression analysis.

RESULTS

The proportions of individuals who were homozygous for the proline allele, and heterozygous for the two allele, homozygous for arginine allele in each group were 15%, 47%, 38% in the SCC group; 6%, 7%, 24% in the adenocarcinoma group; 7%, 33%, 60% in the CIN III group; and 11%, 38%, 51% in the control group. No significant difference was found between the three groups (p>0.05). However there was a significant difference in the adenocarcinoma group (p<0.05). Arg/Arg homozygote reduced the risk of adenocarcinoma. No significant difference existed in 5-year survival rates in the three groups (p=0.22 in SCC, p=0.91 in adenocarcinoma).

CONCLUSION

These findings suggest that Arg/Arg homozygocity of the p53 codon 72 would be a protective factor against the development of cervical adenocarcinoma.

Effects of hand massage on anxiety in cataract surgery using local anesthesia

PURPOSE

To evaluate the effects of hand massage on patient anxiety during cataract surgery.

SETTING

Kangnam St. Mary's Hospital, Seoul, Korea.

METHODS

This study comprised 59 patients having cataract surgery from December 11, 1996, to February 12, 1997. The patients were divided into those having a hand massage 5 minutes before surgery (experimental group, n = 29) and those not receiving a hand massage (control group, n = 30). Patients' anxiety levels were measured using the Visual Analog Scale and by assessing the systolic blood pressure, diastolic blood pressure, and pulse rate before and after the hand massage and 5 minutes before the end of surgery. Epinephrine, norepinephrine, cortisol, blood sugar levels, neutrophil, and lymphocyte percentages in white blood cells were also measured.

RESULTS

After the hand massage, the psychological anxiety levels, systolic and diastolic blood pressures, and pulse rate were significantly lower than before the massage. The hand massage significantly decreased epinephrine and norepinephrine levels in the experimental group. Epinephrine, norepinephrine, and cortisol levels increased in the control group. The differences between groups were significant. There were no significant between-group differences in blood sugar levels or neutrophil and lymphocyte percentages in white blood cells.

CONCLUSION

The findings indicate that hand massage decreases the psychological and physiological anxiety levels in patients having cataract surgery under local anesthesia.

A new method for assessing foliar uptake of fungicides using Congo Red as a tracer

In order to develop a new method for measuring foliar uptake of fungicides, Congo Red was selected as a tracer, and optimum procedures were established for washing, extracting and analyzing it and fungicides from leaf surfaces. Congo Red, a water-soluble dye, was not absorbed into cucumber or rice leaf, even in the presence of various surfactants, and was completely washable from leaf surfaces by aqueous acetonitrile solutions. Congo Red and fungicides in washings were quantified to calculate the amount of foliar uptake of the latter, by comparing the ratio to Congo Red. The optimum concentration of Congo Red in a formulation should be established in order to minimize its influence on fungicide uptake. Although Congo Red has proved to be useful with a conventional droplet application method, it will give more realistic and practical results with the spraying method used in the present study.

Systemic lupus erythematosus complicated with cerebral venous sinus thrombosis : a report of two cases

A rare manifestation of systemic lupus erythematosus (SLE) is cerebral venous sinus thrombosis (CVST), in which early diagnosis and aggressive therapy are of prime importance for favorable outcome. The pathogenesis of CVST is largely unknown, but it is thought to be caused by cerebral vasculitis, antiphospholipid antibodies or other conditions associated with enhanced coagulability. We describe two cases of SLE with CVST which were not associated with antiphospholipid antibodies. Both cases were treated with immunosuppressants (intravenous methylprednisolone and cyclophosphamide pulse therapy) and anticoagulant drugs (heparin and subsequent maintenance therapy with warfarin). There was a marked improvement of neurologic symptoms with the disappearance of thrombus in a follow-up MRI. The possibility of CVST should be considered in any patients with SLE who show neuropsychiatric manifestations.

Expression of recombinant human granulocyte macrophage-colony stimulating factor (hGM-CSF) in mouse urine

We have generated transgenic mice expressing human granulocyte macrophage-colony stimulating factor (hGM-CSF) in urine. In particular, the expression plasmid DNA containing mouse uroplakin II promoter was used to direct uroepithelium-specific transcription of transgene. In this study, hGM-CSF transcript was detected only in bladder uroepithelium as determined by northern blot analysis. Furthermore, hGM-CSF protein was detected in the suprabasal layer of the uroepithelium and ureter by immunohistochemistry. The hGM-CSF was secreted into urine at high level (up to 180 ng/ml), and enhanced proliferation of hGM-CSF-dependent human acute monocyte leukemic cells, suggesting that transgenic urine-derived hGM-CSF was bioactive. This is the first case of demonstrating biological activity of a cytokine produced in the urine of a transgenic animal. Our results demonstrate that bladder can be used as a bioreactor to produce biologically important substances. In addition, it suggests a potential application of bladder expression system to livestock for high-yield production of pharmaceuticals.

Emergence of vaccine-induced escape mutant of hepatitis B virus with multiple surface gene mutations in a Korean child

The S protein of hepatitis B virus is the principal component of virus envelope and the primary target of anti-HBs response. Mutants or variants that escape neutralization by anti-HBs have been selected during immunoprophylaxis of HBV after birth and liver transplantation. We investigated a case of a Korean child who was vaccinated at birth against hepatitis B and also given hepatitis B immunoglobulin, but nevertheless later became infected with the virus. Hepatitis B virus-specific deoxyribonucleic acid covering the region of genome encoding the predominant "a" determinant of hepatitis surface antigen was amplified using polymerase chain reaction, and the nucleotide sequence was determined. We present for the first time in Korea the independent emergence of an escape mutant with substitution of arginine for glycine at amino acid 145 and proline for glutamate at amino acid 120 in "a" determinant after immunization.

Charge-transfer forces in the self-assembly of heteromolecular reactive solids: successful design of unique (single-crystal-to-single-crystal) Diels--Alder cycloadditions

Electron donor/acceptor (EDA) interactions are found to be a versatile methodology for the engineering of reactive heteromolecular crystals. In this way, a series of the charge-transfer pi-complexes between bis(alkylimino)-1,4-dithiin acceptors and anthracene donors are shown to form heteromolecular (1:1) crystalline solids that spontaneously undergo stereoselective [2 + 4] Diels--Alder cycloadditions. The flexible nature of the 1,4-dithiin moiety allows this homogeneous topochemical transformation to proceed with minimal distortion of the crystal lattice. As a result, a unique (single) crystal phase of the Diels--Alder adduct can be produced anti-thermodynamically with a molecular arrangement very different from that in solvent-grown crystals. Such a topochemical reaction between bis(methylimino)-1,4-dithiin and anthracene proceeds thermally and homogeneously up to very high conversions without disintegration of the single crystal. This ideal case of the mono-phase topochemical conversion can be continuously monitored structurally (X-ray crystallography) and kinetically (NMR spectroscopy) throughout the entire range of the crystalline transformation. The resultant "artificial" crystal of the Diels--Alder adduct is surprisingly stable despite its different symmetry and packing mode compared to the naturally grown (thermodynamic) crystal.

Reactive oxygen species mediate A beta(25-35)-induced activation of BV-2 microglia

Microglial activation induced by beta-amyloid (A beta) is an important cellular response in the pathogenesis of Alzheimer's disease (AD). In this study, we show that reactive oxygen species (ROS) play a role as signaling molecules for the activation of NF-kappaB and induction of IL-1beta mRNA expression in A beta(25-35)-treated murine microglia BV-2 cells. ROS scavengers such catalase and superoxide dismutase (SOD) mimetics obviously reduced activation of NF-kappaB and the elevated level of IL-1beta transcripts induced by A beta(25-35). In addition, the A beta(25-35)-induced NF-kappaB activation and IL-1beta expression were suppressed by blockers of the ROS generating enzymes such as NADPH oxidase, cyclooxygenase, and lipoxygenase. These data suggest that ROS mediate A beta-induced microglial activation.

Cholesterol biosynthesis from lanosterol. A concerted role for Sp1 and NF-Y-binding sites for sterol-mediated regulation of rat 7-dehydrocholesterol reductase gene expression

The 7-dehydrocholesterol reductase (Dhcr7) is the terminal enzyme in the pathway of cholesterol biosynthesis. We have previously reported that sterol depletion in vivo caused a significant induction of both liver mRNA and enzyme activity of Dhcr7 (Bae, S.-H., Lee, J. N., Fitzky, B. U., Seong, J., and Paik, Y.-K. (1999) J. Biol. Chem. 274, 14624-14631). In this paper, we also observed liver cell-specific sterol-mediated Dhcr7 gene induction in vitro by sterol depletion in rat hepatoma cells, suggesting the presence of sterol-mediated regulatory elements in the Dhcr7 gene. To understand the mechanisms responsible for regulating Dhcr7 expression, we have isolated the 5'-flanking region of the gene encoding rat Dhcr7 and have characterized the potential regulatory elements of the gene that are responsible for sterol-mediated regulation. The Dhcr7 promoter contains binding sites for Sp1 (at -177, -172, -125, and -20), NF-Y (at -88 and -51), and SREBP-1 or ADD1 (at -33). Deletion analysis of the Dhcr7 gene promoter (-1053/+31), employing a nested series of Dhcr7-luciferase constructs, demonstrated that the -179 upstream region of the gene is necessary and sufficient for optimal efficient sterol-regulated transcription. DNase I footprinting and electrophoretic mobility shift assay showed that the SRE1/E box (-33/-22) involved in sterol response of many sterol-related enzyme genes was protected specifically by the overexpressed recombinant ADD1. Mutational analysis for the functional relationship between the identified cis-elements in this region indicate that one of the binding sites for Sp1 (GC box at -125) and NF-Y (CCAAT box at -88) plays a cooperative role in the sterol-mediated activation, in which the latter site also acts as a co-regulator for SREBP-activated Dhcr7 promoter activity. We believe that Dhcr7 is the first enzyme characterized with a sterol-regulatory function in the post-lanosterol pathway. This may be important for understanding the coordinated control of cholesterol biosynthesis as well as the molecular mechanism of Smith-Lemli-Opitz syndrome-related protein in mammals.

Formation and emission status of PCDDs/PCDFs in municipal solid waste incinerators in Korea

This study was carried out to examine the formation and the emission status of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) in the flue gases of commercial-scale municipal solid waste (MSW) incinerators, and thus to provide the engineering data for the reduction of PCDDs/PCDFs emitted from MSW incinerators. The formation concentrations of the PCDDs/PCDFs generated at the outlet of waste heat boilers (WHB) were in the range of 1.18-29.61 ng-TEQ/N m3 (average 5.75 ng-TEQ/N m3), while the emission concentrations at the stacks were in the range of 0.026-4.548 ng-TEQ/N m3 (average 0.924 ng-TEQ/N m3). Two major 2,3,7,8-substituted congeners were 2,3,4,7,8-PeCDF and 2,3,4,6,7,8-HxCDF, and their concentrations were up to 50% and 64% of total TEQ values at the outlet of WHB and the stack, respectively. From the results of multi-regression analysis, the formation concentration of PCDDs/PCDFs could be predicted as follows with the correlation factor of r2 = 0.962: PCDDs/PCDFs (ng-TEQ/N m3) = 3.036 (Cl) + 0.094 (T1) - 0.472 (Combustibles) + 0.059 (CO) - 0.039 (THC) - 3.366 (H) + 22.157, where T1 (degrees C) is the temperature at the outlet of the WHB. Cl, Combustibles and H are given as percentages and the others are in parts per million.

Protein kinase C-mediated functional regulation of dopamine transporter is not achieved by direct phosphorylation of the dopamine transporter protein

Dopaminergic neurotransmission is terminated by the action of the presynaptic dopamine transporter (DAT). It mediates Na(+)/Cl(-) -dependent re-uptake of extracellular dopamine (DA) into the cell, and is regarded as a major regulatory mechanism for synaptic transmission. Previous works have documented that protein kinase C (PKC) activator or inhibitor alters DA uptake by DAT, suggesting that PKC phosphorylation plays an important regulatory mechanism in DAT function. Based on the existence of consensus amino acid sequences for PKC phosphorylation, it has been postulated that PKC regulation of DAT is mediated by the direct phosphorylation of DAT protein. In this study, we try to discover whether the functional regulation of DAT by PKC is due to direct phosphorylation of DAT. The PKC null mutant hDAT, where all putative PKC phosphorylation sites are eliminated, has been constructed by the replacement of serine/threonine residues with glycines. The mutation itself showed no effect on the functional activities of DAT. The DA uptake activity of PKC null mutant was equivalent to those of wild-type hDAT (80-110% of wild-type). Phorbol ester activation of PKC inhibited DA uptake of wild-type hDAT by 35%, and staurosphorine blocked the effect of phorbol ester on DA uptake. The same phenomena was observed in PKC null mutant DAT, although no significant phosphorylation was observed by PKC activation. Confocal microscopic analysis using EGFP-fused DAT revealed that the activation of PKC by phorbol ester elicited fluorescent DAT to be internalized into the intracellular space both in wild-type and PKC null mutant DAT in a similar way. These results suggest that PKC-mediated regulation of DAT function is achieved in an indirect manner, such as phosphorylation of a mediator protein or activation of a clathrin-mediated pathway.

Comparative analysis of MR imaging, positron emission tomography, and ictal single-photon emission CT in patients with neocortical epilepsy

BACKGROUND AND PURPOSE

MR imaging, positron emission tomography (PET), and single-photon emission CT (SPECT) play important roles in presurgical localization of epileptic foci. However, comparative study of these imaging methods for cases of neocortical epilepsy has been limited. The purpose of this study was to compare the sensitivities of these three imaging methods for presurgical localization of neocortical epileptogenic foci.

METHODS

We studied 117 consecutive patients who underwent surgery for intractable neocortical epilepsy. The pathologic substrates were neuronal migration disorder (n = 77), tumor (n = 15), and others (n = 25). MR imaging was compared retrospectively with (18)F-fluorodeoxyglucose PET and ictal technetium-99m hexamethylpropyleneamine oxime SPECT regarding their capability to correctly localize the epileptogenic foci. The pathologic findings were used as the standard of reference.

RESULTS

Overall, MR imaging, PET, and ictal SPECT correctly localized the lesions for 59.8%, 77.7%, and 70.3% of the patients, respectively, with a 38% concordance rate among the three methods. PET was most sensitive (71-100%) in detecting all substrates. MR imaging was as sensitive (100%) as PET in detecting tumor but was least sensitive (48.1%) in detecting neuronal migration disorder. Ictal SPECT was more sensitive (75.8%) than MR imaging in detecting neuronal migration disorder. Patients with imaging abnormalities achieved good outcomes in 81.4% of the cases, in contrast to 59.5% for those without imaging abnormalities (P <.05).

CONCLUSION

PET and ictal SPECT were overall more sensitive than was MR imaging, despite the low concordance rate and variable sensitivity depending on substrates. The detection of abnormalities by MR imaging was associated with good outcome. PET or ictal SPECT can be well used as complementary tools, particularly in cases of negative MR imaging findings.

High glucose inhibits renal proximal tubule cell proliferation and involves PKC, oxidative stress, and TGF-beta 1

BACKGROUND

The alteration of renal cell growth is one of the early abnormalities in the diabetic nephropathy. However, the effects of high glucose and its action mechanism in renal proximal tubule cell (PTC) proliferation have not been elucidated.

METHODS

The effects of 25 mmol/L glucose on cell proliferation, thymidine, and leucine incorporation, cell cycle, and lipid peroxide formation were examined in the primary cultured renal PTCs.

RESULTS

Glucose 25 mmol/L inhibited [3H]-thymidine incorporation and decreased cell growth. However, it increased [3H]-leucine incorporation and protein content. Furthermore, 25 mmol/L glucose increased lipid peroxide formation. These effects of glucose were blocked by antioxidants, vitamin E, N-acetylcystein, or taurine. Staurosporine and H-7 totally blocked 25 mmol/L glucose-induced lipid peroxide formation and had an inhibitory effect on [3H]-thymidine incorporation. Indeed, 25 mmol/L glucose increased the translocation of protein kinase C (PKC) from cytosolic fraction to membrane fraction. In addition, high glucose increased the secretion of transforming growth factor-beta1 (TGF-beta 1) via the PKC-oxidative stress pathway, and TGF-beta 1 inhibited [3H]-thymidine incorporation in a dose-dependent manner.

CONCLUSIONS

High glucose inhibits renal PTC proliferation via PKC, oxidative stress, and the TGF-beta 1 signaling pathway.