Direct interhemispheric cortical communication via thalamic commissures: a new white matter pathway in the primate brain

Cortical neurons of eutherian mammals project to the contralateral hemisphere, crossing the midline primarily via the corpus callosum and the anterior, posterior, and hippocampal commissures. We recently reported and named the thalamic commissures (TCs) as an additional interhemispheric axonal fiber pathway connecting the cortex to the contralateral thalamus in the rodent brain. Here, we demonstrate that TCs also exist in primates and characterize the connectivity of these pathways with high-resolution diffusion-weighted MRI, viral axonal tracing, and fMRI. We present evidence of TCs in both New World (Callithrix jacchus and Cebus apella) and Old World primates (Macaca mulatta). Further, like rodents, we show that the TCs in primates develop during the embryonic period, forming anatomical and functionally active connections of the cortex with the contralateral thalamus. We also searched for TCs in the human brain, showing their presence in humans with brain malformations, although we could not identify TCs in healthy subjects. These results pose the TCs as a vital fiber pathway in the primate brain, allowing for more robust interhemispheric connectivity and synchrony and serving as an alternative commissural route in developmental brain malformations.

White matter hyperintensities and recurrent stroke risk in patients with stroke with small-vessel disease

BACKGROUND AND PURPOSE

White matter hyperintensities (WMH) are a predictor of stroke among elderly individuals. This study aimed to evaluate the association between WMH severity and the risk of recurrent vascular events among Asian patients with ischaemic stroke with small-vessel disease (SVD) including micro/macrobleeds and lacunes.

METHODS

Data from participants (n = 1454) in the PICASSO (PreventIon of CArdiovascular Events in iSchemic Stroke Patients with High Risk of Cerebral HemOrrhage) trial were reviewed. The severity of WMH in baseline brain magnetic resonance imaging scans was assessed using the Fazekas scale. The association between WMH severity and stroke (ischaemic or hemorrhagic) and major vascular events (MVEs) (a composite of stroke/myocardial infarction/vascular death) was assessed.

RESULTS

Study patients had a significant burden of SVD: Fazekas score 0 (n = 2), 1 (n = 426), 2 (n = 650) and 3 (n = 376) [median Fazekas score 2 (mean follow-up, 1.9 ± 1.3 years)]. The stroke incidence rate per 100 personyears was 2.6 in the Fazekas 0-1 group, 3.6 in the Fazekas 2 group and 7.0 in the Fazekas 3 group, and the rates for MVEs were 3.3, 4.3 and 7.6, respectively. Compared with the Fazekas 0-1 group, the Fazekas 3 group was associated with a higher risk of stroke [adjusted hazard ratio (HR), 2.15; 95% confidence interval (CI), 1.19-3.88; P = 0.011], ischaemic stroke (adjusted HR, 2.11; 95% CI, 1.07-4.15; P = 0.031), hemorrhagic stroke (adjusted HR, 3.72; 95% CI, 1.09-12.70; P = 0.036) and MVEs (adjusted HR, 2.09; 95% CI, 1.20-3.66; P = 0.010).

CONCLUSION

Advanced WMH in Asian patients with ischaemic stroke with SVD burden was associated with an increased risk of recurrent vascular events. It may exert an effect as a prognostic indicator in high risk of recurrent vascular events.

Serum preadipocyte factor 1 concentrations and risk of developing diabetes: a nested case-control study

AIM

To determine whether preadipocyte factor 1 could be a predictive marker for the development of diabetes in people without diabetes at baseline.

METHODS

We conducted a population-based, nested case-control study of individuals who progressed to diabetes (n = 43) or prediabetes (n = 345) and control participants matched on age, sex and fasting plasma glucose concentration, who maintained normal glucose tolerance (n = 389) during a 4-year follow-up using data from the Chungju Metabolic disease Cohort Study. Circulating levels of preadipocyte factor 1 were measured using an enzyme-linked immunosorbent assay.

RESULTS

Baseline serum preadipocyte factor 1 levels showed a stepwise decrease across the glucose tolerance status groups at follow-up (normal glucose tolerance: 10.02 ± 3.02 ng/ml; prediabetes: 9.48 ± 3.35 ng/ml; diabetes: 8.66 ± 3.29 ng/ml; P for trend, 0.0151). Individuals whose fasting plasma glucose level had increased or whose homeostasis model assessment of β-cell function had decreased at follow-up showed significantly lower levels of preadipocyte factor 1 compared with their control group counterparts. After adjusting for age, BMI, fasting plasma glucose, serum insulin levels, systolic blood pressure and triglycerides, the incidence of diabetes was nearly threefold higher in the lowest vs. the upper three quartiles of circulating preadipocyte factor 1 (relative risk 2.794; 95% CI 1.188-6.571; P = 0.0185). Notably, these findings were significant in women but not in men.

CONCLUSIONS

Levels of circulating preadipocyte factor 1 may be a useful biomarker for identifying women at high risk of developing diabetes.

Lower serum zinc levels are associated with unhealthy metabolic status in normal-weight adults: The 2010 Korea National Health and Nutrition Examination Survey

AIM

This study investigated whether serum zinc concentration is associated with glucose tolerance, insulin resistance and metabolic health status in Korean adults.

METHODS

Subjects with available serum zinc levels were recruited from the fifth Korea National Health and Nutrition Examination Survey (KNHANESV) cohort. Those in the highest quartile on homoeostasis model assessment for insulin resistance (HOMA-IR) and with a body mass index (BMI) of 18.5-25kg/m(2) were classified as metabolically obese and normal weight (MONW).

RESULTS

A total of 1813 subjects with a mean age of 45.2±0.5 years and a mean BMI of 24.01±0.11kg/m(2) were enrolled. Those in the lower serum zinc quartiles exhibited higher levels of fasting blood glucose and insulin resistance indices compared with those in the higher quartiles. However, these associations were positive only in normal-weight subjects. Those categorized as MONW exhibited significantly lower serum zinc levels than the metabolically healthy and normal weight (MHNW) subjects (131.6±3.0μg/dL vs 141.7±2.8μg/dL, respectively; P=0.0026), whereas serum zinc levels did not differ according to metabolic health in obese subjects. The odds ratio for being categorized as MONW was 4.12 (95% CI: 1.75, 9.72) among those in the lowest serum zinc quartile compared with those in the highest quartile even after adjusting for possible confounding factors.

CONCLUSION

Lower serum zinc levels were associated with unhealthy metabolic status in normal-weight adults. Further prospective studies are required to define the role of zinc in metabolic health.

Preventive effect of fermented Maillard reaction products from milk proteins in cardiovascular health

The aim of this study was to determine the dual effect of Maillard reaction and fermentation on the preventive cardiovascular effects of milk proteins. Maillard reaction products (MRP) were prepared from the reaction between milk proteins, such as whey protein concentrates (WPC) and sodium caseinate (SC), and lactose. The hydrolysates of MRP were obtained from fermentation by lactic acid bacteria (LAB; i.e., Lactobacillus gasseri H10, L. gasseri H11, Lactobacillus fermentum H4, and L. fermentum H9, where human-isolated strains were designated H1 to H15), which had excellent proteolytic and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities (>20%). The antioxidant activity of MRP was greater than that of intact proteins in assays of the reaction with 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and trivalent ferric ions; moreover, the effect of MRP was synergistically improved by fermentation. The Maillard reaction dramatically increased the level of antithrombotic activity and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) inhibitory effect of milk proteins, but did not change the level of activity for micellar cholesterol solubility. Furthermore, specific biological properties were enhanced by fermentation. Lactobacillus gasseri H11 demonstrated the greatest activity for thrombin and HMGR inhibition in Maillard-reacted WPC, by 42 and 33%, respectively, whereas hydrolysates of Maillard-reacted SC fermented by L. fermentum H9 demonstrated the highest reduction rate for micellar cholesterol solubility, at 52%. In addition, the small compounds that were likely released by fermentation of MRP were identified by size-exclusion chromatography. Therefore, MRP and hydrolysates of fermented MRP could be used to reduce cardiovascular risks.

Evaluation of ABX Pentra DX 120 and Sysmex XE-2100 in umbilical cord blood

INTRODUCTION

Cord blood (CB) is an important source of hematopoietic stem cells and reflects the hematologic status of neonates. ABX Pentra DX 120 (Horiba Medical, Montpellier, France) and Sysmex XE-2100 (Sysmex, Kobe, Japan) were compared in 200 CB specimens.

METHODS

Complete blood count parameters including white blood cell (WBC) differential counts were compared between the two analyzers. Double differential matrix (DDX) by ABX Pentra DX 120 and hematopoietic progenitor cell (HPC) by Sysmex XE-2100 were compared with CD34(+) cells by flow cytometry.

RESULTS

Most of the parameters showed acceptable correlation between the two analyzers. Although WBC differential of both analyzers showed acceptable correlation with manual counts, mononuclear cells (MNC) by ABX Pentra DX 120 better correlated with manual count than MNC by Sysmex XE-2100. NRBC by Sysmex XE-2100 better correlated with manual count than NRBC by ABX Pentra DX 120. ABX Pentra DX 120 showed better flagging performances. DDX better correlated with CD34(+) cells than HPC.

CONCLUSION

Although the results from both analyzers are mostly interchangeable and reliable in CB specimens, flagging performance of ABX Pentra DX 120 seems to be superior to that of Sysmex XE-2100. DDX by ABX Pentra DX 120 would be valuable to evaluate the quality of CB for further therapeutic utilization.

Prevalence and clinical characteristics of diabetic peripheral neuropathy in hospital patients with Type 2 diabetes in Korea

AIMS

Diabetic peripheral neuropathy is a common complication of diabetes. This cross-sectional study investigated the prevalence and clinical characteristics of this neuropathy in patients with Type 2 diabetic mellitus treated at hospitals in Korea.

METHODS

Questionnaires and medical records were used to collect data on 4000 patients with Type 2 diabetes from the diabetes clinics of 40 hospitals throughout Korea. Diabetic peripheral neuropathy was diagnosed based on a review of medical records or using the Michigan Neuropathy Screening Instrument score and monofilament test.

RESULTS

The prevalence of neuropathy was 33.5% (n = 1338). Multivariate analysis revealed that age, female sex, diabetes duration, lower glycated haemoglobin, treatment with oral hypoglycaemic agents or insulin, presence of retinopathy, history of cerebrovascular or peripheral arterial disease, presence of hypertension or dyslipidaemia, and history of foot ulcer were independently associated with diabetic peripheral neuropathy. Of the patients with neuropathy, 69.8% were treated for the condition and only 12.6% were aware of their neuropathy.

CONCLUSION

There was a high prevalence of peripheral neuropathy in patients with Type 2 diabetes in Korea and those patients were far more likely to have complications or co-morbidities. The proper management of diabetic peripheral neuropathy deserves attention from clinicians to ensure better management of diabetes in Korea.

The Dietary Effects of Fermented Chlorella vulgaris (CBT(®)) on Production Performance, Liver Lipids and Intestinal Microflora in Laying Hens

Fermented Chlorella vulgaris CBT^® was evaluated for its effects on egg production, egg quality, liver lipids and intestinal microflora in laying hens. One hundred and eight Hy-line Brown layers (n = 108), 80 wk of age, were fed a basal diet supplemented with CBT^® at the level of 0, 1,000 or 2,000 mg/kg, respectively for 42 d. Egg production was measured daily and egg quality was measured every two weeks. Five eggs from each replicate were collected randomly to determine egg quality. Egg production increased linearly with increasing levels of CBT^® supplementation (p<0.05), although there was no significant effect of treatment on feed intake. Egg yolk color (p<0.001) and Haugh unit (p<0.01) improved linearly with increasing dietary CBT^®. Hepatic triacylglycerol level was linearly decreased with increasing dietary CBT^® (p<0.05). The supplemental CBT^® resulted in linear (p<0.001) and quadratic (p<0.01) response in population of cecal lactic acid bacteria. In conclusion, fermented Chlorella vulgaris supplemented to laying hen diets improved egg production, egg yolk color, Haugh unit and positively affected the contents of hepatic triacylglycerol and the profiles of cecal microflora.

Interventional management for complications following caesarean section

OBJECTIVES

This study aimed to evaluate the efficacy and safety of interventional management for various intractable complications following caesarean section.

METHODS

Between August 2005 and September 2009, 18 consecutive women were referred to interventional radiology for treatment of complications developing after caesarean section. Complications included vaginal bleeding (n = 14), haemoperitoneum with abdominal wall haematoma (n = 2), caesarean scar pregnancy (CSP) (n = 1) and post-caesarean fluid collection (n = 1).

RESULTS

17 women underwent transcatheter arterial embolisation (TAE) with a variety of embolic materials, and two women underwent percutaneous drainage (PCD) for fluid collection and haemoperitoneum. 5 of the 14 women with vaginal bleeding had extravasation of contrast media on angiography; the other 9 had no visible bleeding foci. The two women with haemoperitoneum with abdominal wall haematoma had injury to the inferior epigastric artery from angiography. TAE and PCD were successfully performed in both women. The CSP was successfully managed and the serum β-human chorionic gonadotropin (β-hCG) level finally normalised. Hysterectomy or dilatation and curretage was required in women with placenta accrete and undetectable bleeding foci.

CONCLUSION

Interventional management including TAE and PCD is effective and safe in controlling complications following caesarean section. Use of these procedures can help avoid high-risk surgery, but subsequent procedures including hysterectomy may be required in cases of placental abnormalities and undetectable bleeding foci.

Transcription factor decoy for AP-1 reduces mesangial cell proliferation and extracellular matrix production in vitro and in vivo

Diabetic nephropathy is characterized by an expansion of glomerular mesangium, caused by mesangial cell proliferation and excessive accumulation of extracellular matrix (ECM) proteins, which eventually leads to glomerulosclerosis and renal failure. Activator protein-1 (AP-1), a transcription factor, is implicated in the transcriptional regulation of a wide range of genes participating in cell proliferation and ECM production. This investigation was undertaken to test the hypothesis that AP-1 plays an important role in ECM gene expression, and to develop a molecular therapeutic strategy based on decoy oligodeoxynucleotides (ODN). In this report, we show that transfection with AP-1 decoy ODN strongly inhibits high glucose- and angiotensin II-induced cell proliferation and expression of ECM genes in cultured mesangial cells in vitro. Administration of AP-1 decoy ODN into streptozotocin-induced diabetic rat kidney in vivo using the hemagglutinating virus of Japan (HVJ)-liposome method virtually abolished TGF-beta1 and plasminogen activator inhibitor-1 expression. Our results collectively indicate that AP-1 activation is crucial for mesangial cell proliferation and ECM production in response to high glucose and angiotensin II. Moreover, use of stable AP-1 decoy ODN combined with the highly effective HVJ-liposome method provides a novel potential molecular therapeutic strategy for the prevention of diabetic nephropathy.

Acoustic flowmeter for the measurement of the mean flow velocity in pipes

This paper proposes a new technique for measuring the gas flow velocity averaged along the finite length of a pipe as well as over its cross-sectional area. Unlike the conventional gas flowmeters, the proposed technique exploits the one-dimensional plane waves that propagate uniformly across the pipe cross-sectional area. When a fluid flows along the pipe, the plane waves are superposed with the flow field such that the positive-going and negative-going plane wave components undergo the change of their wave numbers. Such wave number variation due to the mean flow velocity has provided a major motivation for developing a new way of measuring the mean flow velocity in the pipe, which is referred to as the acoustic flowmeter. To examine the feasibility of the developed flow velocity measurement method, including its theoretical backgrounds, experimental setups are illustrated in this paper. Detailed experimental data for the flow velocity range of 2-27 m/s reveal the linearity of the proposed acoustic flowmeter and its salient environmental robustness for the different acoustic pressure patterns in the pipe and, furthermore, for different velocity profiles over the pipe cross-section area.

Resolution enhancement in standing-wave total internal reflection microscopy: a point-spread-function engineering approach

The theoretical basis for resolution enhancement in standing-wave total internal reflection microscopy (SW-TIRM) is examined. This technique relies on the formation of an excitation field containing super-diffraction-limited spatial-frequency components. Although the fluorescence generated at the object planes contains high-frequency information of the object distribution, this information is lost at the image plane, where the detection optics acts as a low-pass filter. From the perspective of point-spread-function (PSF) engineering, one can show that if this excitation field is translatable experimentally, the high-frequency information can be extracted from a set of images where the excitation fields have different displacement vectors. We have developed algorithms to combine this image set to generate a composite image with an effective PSF that is equal to the product of the excitation field and the Fraunhofer PSF. This approach can easily be extended to incorporate nonlinear excitation modalities into SW-TIRM for further resolution improvement. We theoretically examine high-resolution imaging based on the addition of two-photon, pump-probe, and stimulated-emission depletion methods to SW-TIRM and show that resolution better than 1/20 of the emission wavelength may be achievable.

Posttranscriptional regulation of human ADH5/FDH and Myf6 gene expression by upstream AUG codons

Upstream open-reading frames are unusual in mammalian mRNAs. The 5' untranslated region of ADH5 mRNA contains an upstream open-reading frame (uORF) with two possible AUG start codons. Myf6 mRNA contains three tandem AUG repeats at the translation start site, a rare feature. Mutation at one or both of the upstream AUG codons in the ADH5 mRNA increased gene expression twofold in CV-1, NIH/3T3, HeLa, and SL2 cells. Mutation of these AUG codons led to 3- to 5-fold increases in activity as measured by in vitro translation assays using capped mRNAs. RNA toeprint analysis demonstrated many stalled ribosomes flanking the AUG codons and secondary structures near the AUGs. Secondary structures may increase the ability of ribosomes to recognize the two AUGs, despite their poor initiation context. The degree of repression by uAUGs varied significantly depending on the cell lines tested, which may partly explain the differential tissue expression. Myf6 is a critical myogenic transcription factor with the striking feature of three tandem AUG codons at the translation initiation site. This structure reduced expression; removing two of these AUGs led to a doubling of activity in CV-1, HeLa, and NIH/3T3 cells.

Efficacy of flubendazole and albendazole against Trichinella spiralis in mice

Efficacy of flubendazole and albendazole against Trichinella spiralis in mice were studied. ICR mice were experimentally infected with Trichinella spiralis and treated with either flubendazole (FBZ) or albendazole (ABZ) at four different stages of the parasite life-cycle. Oral administration of either FBZ or ABZ at 20 mg/kg and 50 mg/kg on 2 h, 8 h and 24 h (pre-adult stage) after infection eliminated 94.7-100% of adults as determined at necropsy on day 7 post infection (p.i.) and 96.9-100% of larvae on day 45 p.i. FBZ was more effective than ABZ against adult T. spiralis (at 2 to 6 days p.i.), when treated with a dosage of 20 mg/kg for 5 consecutive days (99.4% and 46.0% reduction with respect to the control group). Against migrating larval T. spiralis, FBZ was more effective than ABZ at 20 mg/kg for five consecutive days (on days 11-15 p.i.), and the reduction rate of recovered larvae were 99.6% (FBZ) and 80.8% (ABZ) respectively. FBZ was more effective against early encapsulated larval T. spiralis (at 21 to 25 days p.i.), than ABZ when both were given at 20 mg/kg for five consecutive days (99.8% and 45.4% reduction, respectively). In conclusion, flubendazole was more effective than albendazole against adult and parenteral stages of Trichinella spiralis in mice.

PCR-RFLP patterns of four isolates of Trichinella for rDNA ITS1 region

We have studied the genetic differences among four isolates of Trichinella including a new strain of Trichinella spiralis (ISS 623) recently found from a human case who took a badger in Korea. Because they have a different host origin and came from geographically separated regions, we supposed the genetic pattern of the isolates might be different as had been previously reported. It was analysed by PCR-RFLP analysis of the rDNA repeat that can readily distinguish a species or strain from others. Isolated genomic DNA of each isolate of Trichinella larvae was amplified with ITS1 specific primers and digested with restriction endonucleases. The PCR product of ITS1 was confirmed using Southern blot analysis to be a 910 bp fragment. The restriction fragments of each isolate had variable patterns when it was digested with Rsa 1 only. According to the RFLP patterns, the estimated genetic divergence between each isolate was different. In conclusion, four isolates of Trichinella including a new strain of T. spiralis obtained from a Korean patient may have genetic differences in the ITS1 region and the Shanghai isolate was genetically more similar to the Japanese unknown isolate than others in the ITS1 region.

SJ-3366, a unique and highly potent nonnucleoside reverse transcriptase inhibitor of human immunodeficiency virus type 1 (HIV-1) that also inhibits HIV-2

We have identified and characterized a potent new nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) of human immunodeficiency virus type 1 (HIV-1) that also is active against HIV-2 and which interferes with virus replication by two distinct mechanisms. 1-(3-Cyclopenten-1-yl)methyl-6-(3,5-dimethylbenzoyl)-5-ethyl-2,4-pyrimidinedione (SJ-3366) inhibits HIV-1 replication at concentrations of approximately 1 nM, with a therapeutic index of greater than 4 x 10(6). The efficacy and toxicity of SJ-3366 are consistent when evaluated with established or fresh human cells, and the compound is equipotent against all strains of HIV-1 evaluated, including syncytium-inducing, non-syncytium-inducing, monocyte/macrophage-tropic, and subtype virus strains. Distinct from other members of the pharmacologic class of NNRTIs, SJ-3366 inhibited laboratory and clinical strains of HIV-2 at a concentration of approximately 150 nM, yielding a therapeutic index of approximately 20,000. Like most NNRTIs, the compound was less active when challenged with HIV-1 strains possessing the Y181C, K103N, and Y188C amino acid changes in the RT and selected for a virus with a Y181C amino acid change in the RT after five tissue culture passages in the presence of the compound. In combination anti-HIV assays with nucleoside and nonnucleoside RT and protease inhibitors, additive interactions occurred with all compounds tested with the exception of dideoxyinosine, with which a synergistic interaction was found. Biochemically, SJ-3366 exhibited a K(i) value of 3.2 nM, with a mixed mechanism of inhibition against HIV-1 RT, but it did not inhibit HIV-2 RT. SJ-3366 also inhibited the entry of both HIV-1 and HIV-2 into target cells. On the basis of its therapeutic index and multiple mechanisms of anti-HIV action, SJ-3366 represents an exciting new compound for use in HIV-infected individuals.

Changes of splenocyte IFN-gamma mRNA synthesis in rats infected with Paragonimus westermani

Changes in the expression level of splenocyte IFN-gamma mRNA of Sprague-Dawley (SD) rats infected with Paragonimus westermani were analyzed by competitive reverse transcription-polymerase chain reaction (RT-PCR) followed by southern blot. The template RNA was extracted from the splenocytes of rats infected with 20 metacercariae of P. westermani. The products of competitive RT-PCR were subjected to southern blot and enhanced chemiluminescence (ECL), and analyzed with a densitometer. In comparison with that of uninfected control rat splenocytes (value of 1), the levels of mRNA expression of IFN-gamma had changed to 0.747 at 1 week post infection (PI), 0.00175 at 2 week PI, 0.0217 at 3 week PI, 0.194 at 4 week PI and then to 0.537 at 5 week PI. The level at 7 week PI had returned to 1.25, comparable with that of uninfected rats. These results show that, when infected with P. westermani, the levels of IFN-gamma mRNA of SD rat splenocytes were remarkably reduced by more than 500 times at 2 week PI and restored to normal level at 7 week PI.

Biochemical oxygen demand sensor using Serratia marcescens LSY 4

A microbial biochemical oxygen demand (BOD) sensor consisting of Serratia marcescens LSY 4 and an oxygen electrode was prepared for estimation of the biochemical oxygen demand. The response of the BOD sensor was insensitive to pH in the range of pH 6.0-8.0, and the baseline drift of the signal was nearly absent even in unbuffered aqueous solution. Because heavy metal ions were precipitated from the phosphate buffer solution, unbuffered solution was used to investigate the effect of the concentration of heavy metal ions on the sensor response. Contrary to previous studies, not only Cu2+ and Ag+ but also Cd2+ and Zn2+ significantly decreased the response of the BOD sensor in unbuffered solution. Graft polymerization of sodium styrene sulfonate on the surface of the porous teflon membrane was carried out to absorb the heavy metal ions permeating through the membrane. Tolerance against Zn2+ was induced for S. marcescens LSY 4 to make the cells less sensitive to the presence of heavy metal ions. The membrane modification and the Zn2+ tolerance induction showed some positive effects in such a way that they reduced the inhibitory effects of Zn2+ and Cd2+ on the sensitivity of the BOD sensor. However, they had no effect on the protection of the cells against the interference of Cu2+ and Ag+ on the performance of the sensor.

Sp3 and Sp4 can repress transcription by competing with Sp1 for the core cis-elements on the human ADH5/FDH minimal promoter

The human alcohol dehydrogenase 5 gene (also known as the formaldehyde dehydrogenase gene, ADH5/FDH) has a GC-rich promoter with many sites at which transcription factors bind. A minimal promoter extending from -34 base pairs (bp) to +61 bp directs high levels of transcription in several different cells, consistent with the ubiquitous expression of the gene. Nearly the entire minimal promoter can be bound by Sp1. We analyzed the transcriptional regulation of ADH5/FDH by members of the Sp1 multigene family. Two core cis-elements (-22 bp to +22 bp) had the highest affinity for Sp1. Mutagenesis revealed that these cis-elements are critical for transcriptional activation. The zinc-finger domains of Sp3 and Sp4 also bind selectively to the core cis-elements. In Drosophila SL2 cells, which lack endogenous Sp1, the minimal promoter cannot drive transcription. Introduction of Sp1 activated transcription over 50-fold, suggesting that Sp1 is critical in the initiation of transcription. Neither Sp3 nor Sp4 was able to activate transcription in those cells, and transcriptional activation by Sp1 was repressed by Sp3 or Sp4. These data suggest that Sp3 and Sp4 can repress transcription by competing with Sp1 for binding to the core cis-elements. The content of Sp1, Sp3, and Sp4 in different cells may be critical factors regulating transcription of the ADH5/FDH gene.

Effect of IciA protein on the expression of the nrd gene encoding ribonucleoside diphosphate reductase in E. coli

The E. coli nrd operon contains the genes encoding the two subunits of ribonucleoside diphosphate reductase. We found that the IciA protein binds specifically to the AT-rich upstream region of nrd promoter. In vivo overexpression of IciA increases the expression of nrd gene by four- to five-fold, suggesting that IciA functions as a transcriptional activator for the nrd gene.

Characterization of cell lines established from human hepatocellular carcinoma

We characterized 8 human hepatocellular-carcinoma cell lines established from the primary tumors of Korean patients. All lines showed substrate adherence and one line from anaplastic tumor also grew as floating aggregates. Most cultured cells maintained many morphological characteristics of the original tumors from which they were derived. Doubling times varied from 34 to 72 hr. All lines showed relatively high viability and were not contaminated with Mycoplasma or bacteria. All lines showed aneuploidy and were proven to be unique by DNA fingerprinting analysis. Hepatitis-B-virus (HBV) DNA was integrated in the genomes of all lines. Two of the cell lines (SNU-354, SNU-368) showed expression of HBV and HBVx (HBx) transcripts. SNU-354 strongly expressed albumin, and SNU-368 expressed transferrin and insulin-like growth factor II. No lines produced alpha-fetoprotein at the RNA and protein level. These cell lines represent useful tools for in vitro studies related to hepatocellular carcinoma.