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Biomedical subjects

J Choi

Publications and source records attributed to J Choi.

At least 91 records · Page 5Linked to original sources
PubMed2001

Prior exposure of mice to Fusobacterium nucleatum modulates host response to Porphyromonas gingivalis.

Multiple periodontal pathogens sequentially colonize the subgingival niche during the conversion from gingivitis to destructive periodontal disease. An animal model of sequential immunization with key periodontal pathogens has been developed to determine whether T- and B-lymphocyte effector functions are skewed and fail to protect the host from pathogenic challenge. The present study was performed to evaluate the immunomodulatory effect of exposure to Fusobacterium nucleatum prior to Porphyromonas gingivalis. Group 1 (control) mice were immunized with phosphate-buffered saline, group 2 were immunized with F. nucleatum prior to P. gingivalis and group 3 were immunized with P. gingivalis alone. All the T-cell clones derived from group 2 demonstrated type 2 helper T-cell clone (Th2 subsets), whereas those from group 3 mice demonstrated Th1 subsets. Exposure of mice to F. nucleatum prior to P. gingivalis interfered with the opsonophagocytosis function of sera against P. gingivalis. In adoptive T-cell transfer experiments, in vivo protective capacity of type 2 helper T-cell clones (Th2) from group 2 was significantly lower than type 1 helper T-cell clones (Th1) from group 3 against the lethal dose infection of P. gingivalis. Western blot analysis indicated a different pattern of recognition of P. gingivalis fimbrial proteins between sera from group 2 and group 3. In conclusion, these studies suggest that exposure of a host to F. nucleatum prior to the periodontal pathogen P. gingivalis modulates the host immune responses to P. gingivalis at the humoral, cellular and molecular levels.

Adjuvants, Immunologic↗
PubMed2001

Efficient gene transfer of VSV-G pseudotyped retroviral vector to human brain tumor.

A retroviral vector constructed from the murine leukemia virus (MLV) can only express transgenes in cells undergoing mitosis, indicating its suitability as a delivery vehicle for cancer gene therapy. However, the transduction efficiency (TE) of retroviruses embedding endogenous envelope proteins in human cancer cells was found to be unsatisfactory. Recently, several research groups have demonstrated the feasibility of a retroviral vector pseudotyped with a vesicular stomatitis virus G (VSV-G) protein. In this study, the potential of VSV-G pseudotyped MLV-based retrovirus was examined as a delivery vehicle in a variety of human cancer cells including brain tumor cells in vitro and in vivo. The transduction efficiency of the 293T/G/GP/LacZ retrovirus in cell culture was superior in most cancer cells, particularly in brain tumor cells, compared with that of other retroviruses, such as PA317- or PG13-derived. The relative growth rate and phosphatidylserine expression level on the plasma membrane of target cells mainly influenced the transduction efficiency of VSV-G pseudotyped retrovirus, which suggested that both the relative growth rate and phosphatidylserine expression level were major determinants of TE. Furthermore, 293T/G/GP/LacZ could efficiently transduce human cancer cells regardless of the presence of chemical additives, whereas in other retroviruses, cationic chemical additives such as polybrene or liposomes were essential during virus infection. Finally, an average of 10% gene expression was routinely obtained exclusively in the tumor mass when 293T/G/GP/LacZ concentrated by simple ultracentrifugation was directly administrated to pre-established brain tumors in animal models (U251-N nu/nu mice or C6 Wistar rats). All told, the present study suggests that the VSV-G pseudotyped retrovirus is a suitable vector for brain tumor gene therapy.

Brain Neoplasms↗
PubMed2001

Expression of thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection.

We evaluated the expression of thymidylate synthase (TS) in locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection and investigated the association between TS expression and clinicopathologic characteristics including prognosis of the patients. TS expression was evaluated by immunohistochemical staining using TS106 monoclonal antibody in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil (5-FU) and doxorubicin-based adjuvant chemotherapy after curative resection. 65 patients (63%) had primary tumours with high TS expression (> or = 25% of tumour cells positive), and 38 patients (37%) demonstrated low TS expression (< 25% of tumour cells positive or no staining). High TS expression was associated with male gender (P = 0.002), poorly differentiated histology (P = 0.015), and mixed type in Lauren's classification (P = 0.027). There were no statistically significant differences in 4-year disease-free survival (60.0% vs. 57.2%, P = 0.548) and overall survival (59.6% vs. 59.3%, P = 0.792) between high-TS group and low-TS group. In conclusion, although high TS expression was associated with poorly differentiated histology and mixed type in Lauren's classification, it did not predict poor disease-free and overall survival in gastric cancer patients treated with 5-FU and doxorubicin-based adjuvant chemotherapy after curative resection. Further prospective studies including the evaluation of other biological markers associated with the resistance to 5-FU and doxorubicin are necessary.

Adult↗
PubMed2001

Experimental assessment of non-treated bentonite as the buffer material of a radioactive waste repository.

The bentonite-based material being evaluated in several countries as potential barriers and seals for a nuclear waste disposal system is of mostly sodium type, whereas most bentonite available in Korea is known to be of calcium type. In order to investigate whether local Korean bentonite could be useful as a buffer or sealing material in an HLW repository system, raw bentonites sampled from the south-east area of Korea were examined in terms of their physicochemical properties such as surface area, CEC, swelling rate, and distribution coefficient. The diffusion behavior of some radionuclides of interest in compacted bentonite was also investigated. Considering that HLW generates decay heat over a long time, the thermal effect on the physicochemical properties of bentonite was also included. Four local samples were identified as Ca-bentonite through XRD and chemical analysis. Of the measured values of surface area, CEC and swelling rate of the local samples, Sample-A was found to have the greatest properties as the most likely candidate barrier material. The distribution coefficients of Cs-137, Sr-85, Co-60 and Am-241 for Sample-A sample were measured by the batch method. Sorption equilibrium was reached in around 8 to 10 days, but that of Sr was found to be reached earlier. Comparing the results of this study with the reference data, domestic bentonite was found to have a relatively high sorption ability. For the effect of varying concentration on sorption, the values of Kd peaked at 10(-9)-10(-7) mol/l of radionuclide concentration. In XRD analysis, the (001) peak of Sample-A was fully collapsed above 200 degrees C. The shoulder appearing at about 150 degrees C in the DSC curve was found to be evidence that Sample-A is predominated by Ca-montmorillonite. The loss of swelling capacity and CEC of Sample-A started at about 100 degrees C. The swelling data and the (001) peak intensity of the heat-treated sample showed that they were linearly interrelated. The measured Kd values of Co-60, Cs-137 and Am-241 for the samples heat-treated at various temperature showed that the domestic bentonite still retained sorption capacity below 100 degrees C. In addition to such findings of thermal effects, it was found that the presence of calcium in bentonite may help to assure long-term stability under the expected thermo-hydro conditions. The Da values of Sr-85, Cs-137, Co-60, Am-241 and Cl-36 were measured to be 1.073 x 10(1), 6.705 x 10(-1), 1.226 x 10(-1), 1.310 x 10(-2) and 9.490 x 10(1) microns 2/sec, respectively, which could be arranged with the magnitude of their distribution coefficients, i.e. Cl > Sr > Cs > Co > Am. As the as-pressed density of bentonite increasing from 1.8 to 2.0 g/cm3, the Da-value of Cs-137 decreased by 25%. From the analyses of the diffusion mechanism of radionuclides in compacted bentonite, the surface diffusion due to the concentration gradients of radionuclide sorbed on the bentonite particles was found to be a dominating transport process of radionuclides in compacted bentonite with 1.8 g/cm3. Bases on these results, it was identified that domestic bentonite has potential as a chemical barrier material in a repository system. Some data obtained in the results could contribute to the engineering parameters to design a waste package and engineered barrier or to develop an appropriate disposal concept satisfying the safety requirements.

Bentonite↗
PubMed2001

Genomic analysis and localization of murine Deltex, a modulator of notch activity, to mouse chromosome 5 and its human homolog to chromosome 12.

Deltex is a component of the Notch signaling network, which mediates cellular differentiation, proliferation, and apoptosis during development. Murine Deltex was initially isolated as a cDNA transcript that displayed increased expression in T-cell tumors induced by gamma irradiation. The in vivo function of Deltex is unknown; however, the emerging role of Notch signaling in T-cell development and lymphomagenesis indirectly supports a role for Deltex in these processes. To investigate the regulation of Deltex expression in both normal and transformed tissue, we have begun analyzing the Deltex genomic locus. Here, we report the exon-intron organization of Deltex and map the locus to the middistal region of mouse chromosome 5, tightly linked to the Adam1a, Lnk, Tbx5, and Nos1 loci. The human homolog of Deltex has been localized to chromosome 12.

3' Untranslated Regions↗
PubMed2001

Synaptic deprivation and age-related vulnerability to hypoxic-ischemic neuronal injury. A hypothesis.

Advanced age is associated with physiological changes, such as cerebral autoregulation dysfunction, atrial fibrillation, reduced cerebral blood flow, elevated blood pressure, and other changes. Stroke-related dementia is associated with brain loss principally due to strokes, and neuropathological examination of the brains of old people shows a direct correlation between the extent of brain loss and dementia. However, the exact mechanism of the age related vulnerability to hypoxic-ischemic neuronal injury remains unknown. The majority of synapses in the brain use excitatory amino acids as their neurotransmitter. Glutamate, a major endogenous excitatory amino acid required for normal physiological excitation, is also involved in the pathophysiology of hypoxic-ischemic neuronal injury. The N-methyl-D-aspartate (NMDA) glutamate receptor subtype plays a major role in mediating hypoxic-ischemic neuronal injury. NMDA receptors also mediate adaptive responses important for synaptic plasticity. This report explores the possible role of synaptic activity as a protective mechanism against neuronal cell death. Specifically, the role of NMDA receptors in neuronal plasticity by upregulating a survival pathway is discussed. Loss of a neuronal population that uses glutamate as its neurotransmitter leads to a loss of activity on the postsynaptic neurons or synaptic deprivation. Deprivation of excitatory amino acids on the postsynaptic neurons results in the failure of activity-dependent induced intrinsic survival pathways induced by NMDA receptors. The loss of neuroprotective intrinsic survival pathways increases the vulnerability of these neurons to more hypoxic-ischemic neuronal damage. Since cerebral infarction is also age related, this hypothesis provides a plausible explanation of how we become more vulnerable to hypoxic-ischemic neuronal injury as a function of age.

Age Factors↗
PubMed2001

The arginine-1493 residue in QRRGRTGR1493G motif IV of the hepatitis C virus NS3 helicase domain is essential for NS3 protein methylation by the protein arginine methyltransferase 1.

The NS3 protein of hepatitis C virus (HCV) contains protease and RNA helicase activities, both of which are likely to be essential for HCV propagation. An arginine residue present in the arginine-glycine (RG)-rich region of many RNA-binding proteins is posttranslationally methylated by protein arginine methyltransferases (PRMTs). Amino acid sequence analysis revealed that the NS3 protein contains seven RG motifs, including two potential RG motifs in the 1486-QRRGRTGRG-1494 motif IV of the RNA helicase domain, in which arginines are potentially methylated by PRMTs. Indeed, we found that the full-length NS3 protein is arginine methylated in vivo. The full-length NS3 protein and the NS3 RNA helicase domain were methylated by a crude human cell extract. The purified PRMT1 methylated the full-length NS3 and the RNA helicase domain, but not the NS3 protease domain. The NS3 helicase bound specifically and comigrated with PRMT1 in vitro. Mutational analyses indicate that the Arg(1493) in the QRR(1488)GRTGR(1493)G region of the NS3 RNA helicase is essential for NS3 protein methylation and that Arg(1488) is likely methylated. NS3 protein methylation by the PRMT1 was decreased in the presence of homoribopolymers, suggesting that the arginine-rich motif IV is involved in RNA binding. The results suggest that an arginine residue(s) in QRXGRXGR motif IV conserved in the virus-encoded RNA helicases can be posttranslationally methylated by the PRMT1.

Amino Acid Motifs↗
PubMed2001

Effects of bergenin, the major constituent of Mallotus japonicus against D-galactosamine-induced hepatotoxicity in rats.

The hepatoprotective effects of bergenin, a major constituent of Mallotus japonicus, were evaluated against D-galactosamine (GalN)-induced liver damage in rats. Bergenin (50, 100 and 200 mg/kg) was given orally once daily for 7 successive days and then GalN 400 mg/kg was injected intraperitoneally to rats at 24 and 96 h after the final administration of bergenin. Pretreatment with bergenin reduced the increased enzyme activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase, gamma-glutamyltransferase and the elevated level of malondialdehyde induced by GalN. Bergenin restored the decreased hepatic contents of glutathione as well as the decreased activities of glutathione S-transferase and glutathione reductase by GalN towards normalization, suggesting that the hepatoprotective effects of bergenin may consist in maintaining adequate levels of hepatic glutathione for the removal of xenobiotics. The present results indicate that bergenin has hepatoprotective effects against GalN-induced hepatotoxicity in rats.

Animals↗
PubMed2001

Tissue distribution and genetic typing of porcine circoviruses in pigs with naturally occurring congenital tremors.

Congenital tremors (CT) type A2 is associated with porcine circovirus (PCV) and deficient and abnormal myelin. The aim of this study was to determine the tissue distribution and genetic type of PCV in 1-2-day-old pigs with naturally occurring CT type A2 using in situ hybridization, polymerase chain reaction (PCR), and indirect fluorescent antibody tests on frozen tissue sections. CT-affected and clinically normal pigs were selected from 4 farms in the midwestern USA that were undergoing outbreaks of CT type A2. All CT and most normal pigs were infected with PCV. PCV was widely distributed in tissues of infected pigs and was most common in tissues of the central nervous system and liver. In all infected pigs, there were more PCV-infected cells in brain and spinal cord than in nonneural tissues. CT pigs had many more PCV-infected cells in the brain and spinal cord than did clinically normal pigs because of a more diffuse distribution and a larger proportion of infected cells. The cells most commonly infected with PCV in brain and spinal cord were large neurons. In nonneural tissues, macrophages were the most frequent cell type infected. PCR analysis demonstrated only PCV type 2 and not PCV type 1 in all PCV-infected pigs on all 4 farms.

Animals↗
PubMed2001

Effect of dopamine on excretory urographic image quality and the prevention of contrast-induced nephropathy in dogs.

The effect of low dose dopamine on the excretory urographic image quality and contrast media-induced nephropathy in normal dogs (experiment 1) and the dogs with decreased renal function (experiment 2) were assessed. In experiment 2, decreased renal function was induced by gentamicin overdose. In each experiment, animals were divided into 3 groups. In group 1, only contrast medium (iohexol) was administered. In group 2, contrast medium plus intravenous fluid (0.9% saline) were administered. And in group 3, contrast medium plus intravenous fluid and low dose dopamine were administered. Investigated parameters included intrarenal resistive index (RI), serum BUN and creatinine concentrations, contrast medium elimination time and radiographic image quality. In experiment 1, RI of group I increased at 80 min after contrast medium administration (p<0.05), but RI of group 3 decreased at 48 and 72 hr (p<0.05). Serum BUN concentration of group 1 was higher than that of group 2 and 3 (p<0.05); in radiographic examination, contrast medium elimination time decreased in group 2 and 3, but image quality of group 2 was inferior to that of group 3. In experiment 2, image quality of group 3 only provided adequate visualization of renal structures. The formula of contrast medium plus low dose dopamine was found to provide good nephrogram and pyelogram image quality without supplemental contrast medium, and to protect renal tubules from prolonged exposure to concentrated contrast medium.

Animals↗
PubMed2001

Viral replication and lesions in BALB/c mice experimentally inoculated with porcine circovirus isolated from a pig with postweaning multisystemic wasting disease.

Eight-week-old BALB/c mice were either sham inoculated (control mice) or were inoculated intraperitoneally (IP) and intranasally (IN) with a single (sPCV mice) or multiple (mPCV mice) doses of porcine circovirus 2 (PCV2). Four control mice and 4 sPCV mice were sacrificed 7, 14, 28, and 42 days postinoculation (PI). All 4 mPCV mice were sacrificed 42 days PI. In addition, 7-day and 14-day pregnant BALB/c mice were either sham inoculated (control mice) or were inoculated IP and IN with a single dose of PCV2. Newborn mice were euthanatized 1, 8, and 15 days after birth. Necropsies were performed on all euthanatized mice and tissues were collected for histopathology, electron microscopy, in situ hybridization, and polymerase chain reaction (PCR). PCV2 replicated in 8-week-old BALB/c mice that were inoculated with PCV2 and caused fetal infection when inoculated into pregnant BALB/c mice at 7 days and 14 days of gestation. PCV was detected by in situ hybridization and PCR in sPCV mice on days 7, 14, 28, and 42 PI; in mPCV mice on day 42 PI; and in newborn mice from mothers inoculated with PCV at 7 days and 14 days of gestation at 1, 8, and 15 days after birth, but not in control mice. No clinical signs or gross lesions were found in sPCV or mPCV mice during the study. Microscopic lesions in sPCV mice and mPCV mice were characterized by expansion of germinal centers in lymphoid organs with large numbers of histiocytic cells and lymphoblasts, apoptosis of histiocytic cells in germinal centers, and mild lymphoid depletion of the paracortex. PCV nucleic acid was detected in the nuclei and cytoplasm of histiocytes and apoptotic cells in germinal centers in lymphoid tissues as well as in the nuclei of hepatocytes in the liver, in the nuclei of renal tubular epithelial cells, and in the cytoplasm of single lymphocytes in the thymus. Congenitally infected mice only had PCV nucleic acid detected in putative Kupffer cells in livers.

Animals↗
PubMed2001

BAX contributes to apoptotic-like death following neonatal hypoxia-ischemia: evidence for distinct apoptosis pathways.

BACKGROUND: Hypoxic-ischemic (H-I) injury to the neonatal brain has been shown to result in rapid cell death with features of acute excitotoxicity/necrosis as well as prominent delayed cell death with features of apoptosis such as marked caspase-3 activation. BAX, a pro-apoptotic molecule, has been shown to be required for apoptotic neuronal cell death during normal development but the contribution of endogenous BAX in cell death pathways following H-I injury to the developing or adult brain has not been studied. MATERIALS AND METHODS: Bax +/+, +/-, and -/- mice at post-natal day 7 were subjected to unilateral carotid ligation followed by exposure to 45 minutes of 8% oxygen. At different timepoints following H-I, brain tissue was studied by conventional histology, immunohistochemistry, immunofluorescence, Western blotting, and enzymatic assay to determine the extent and type of cell injury as well as the amount of caspase activation. RESULTS: We found that bax -/- mice had significantly less (38%) hippocampal tissue loss than mice expressing bax. Some of the remaining cell death in bax -/- mice, however, still had features of apoptosis including evidence of nuclear shrinkage and caspase-3 activation. Though bax -/- mice had significantly decreased caspase-3 activation as compared to bax expressing mice following H-I, the density of cells with activated caspase-8 in the CA3 region of the hippocampus did not differ between bax +/- and bax -/- mice. CONCLUSIONS: These findings demonstrate that endogenous BAX plays a role in regulating cell death in the central nervous system (CNS) following neonatal H-I, a model of cerebral palsy. In addition, while BAX appears to modulate the caspase-3 activation following neonatal H-I, caspase-8 which is linked to death receptor activation, may contribute to apoptotic-like neuronal death in a BAX-independent manner.

Animals↗
PubMed2001

Angiogenesis effects of nerve growth factor (NGF) on rat corneas.

This study was performed to evaluate the effects of nerve growth factor (NGF) upon angiogenesis in the rat cornea, to examine its possible application as an alternative angiogenic inducer and to provide basic data for further studies. Angiogenesis was induced by cornea micropocket assay, as previously described. Eight of thirty two eyes of Sprague-Dawley rats were randomly assigned to one of four groups, namely, a non-NGF group (Group 0), a 0.5 ng of NGF group (Group 0.5), a 1.0 ng of NGF group (Group 1.0) and a 5.0 ng of NGF group (Group 5.0). Pellets made of poly-2-hydroxylethylmethacrylate and sucralfate were implanted into the corneal stroma no closer than 1 mm from the limbus. After the implantation, the number of new vessels, vessel length and circumferential neovascularization were examined daily under the surgical microscope over a period of 7 days. The area of neovascularization was determined using a mathematical formula. Although new vessels in Group 0 and Group 0.5 were first observed at day 5, those of Groups 1.0 and 5.0 were first noted on days 4 and 3, respectively. However, the growth rates of new vessels in Groups 1.0 and 5.0 were higher than those of Groups 0 and 0.5 with the passage of time. The number, length, circumferential neovascularization and areas covered by the vessels in Groups 1.0 and 5.0 were significantly more than in Group 0 and Group 0.5 (p<0.05). This study showed that NGF had a dose-dependent angiogenic effects on the rat cornea and that the minimal effective dose of NGF was 1.0 ng per cornea. Also, it showed that NGF would be useful in angiogenic studies as an alternative angiogenic inducer.

Angiogenesis Inducing Agents↗
PubMed2000

Subcellular localization of the expressed 18 kDa FGF-2 isoform in corneal endothelial cells.

PURPOSE: To determine the subcellular localization of 18 kDa FGF-2 after synthesis and before secretion into the extracellular matrix. METHODS: Corneal endothelial cells (CEC) were transfected with an expression vector coding for green fluorescent protein (GFP) and 18 kDa FGF-2. Expression of the fusion protein was determined by immunoblot analysis and the subcellular localization of the fusion protein was examined by immunocytochemical analysis. RESULTS: When the expression of the fusion protein was determined by immunoblot analysis, the expressed fusion protein had a molecular weight of 45 kDa, resulting from the 27 kDa GFP and 18 kDa FGF-2. Following a 90 min exposure of cells to the vector, the expressed 18 kDa FGF-2 was completely translocated to the nucleus within a 24 h incubation. When cells were further incubated for another 24 h, one-half of the fusion protein was retro-transported from the nucleus to the cytoplasm, largely to the membrane and focal adhesion site, while the other half remained in the nucleus. During a 72 h incubation, the fusion protein was completely translocated to the cytoplasm, where it was diffusely distributed and its staining potential was greatly lost. Transfected cells showed both a slight increase in cell proliferation and a down-regulation in the expression of the high affinity receptors of FGF. CONCLUSIONS: These results indicate that the 18 kDa FGF-2 is directly translocated from its synthetic site to the nucleus. The nuclear 18 kDa FGF-2 is then retro-transported to membrane/focal adhesion sites, after which the molecule may be secreted. When 18 kDa FGF-2 remains in the nucleus, there is a slight stimulatory activity of cell proliferation and a down-regulation of its receptor. These data suggest an intracellular action of 18 kDa FGF-2 through mechanisms independent of the receptor-mediated signaling pathways.

Animals↗
PubMed2000

Oncolytic potential of E1B 55 kDa-deleted YKL-1 recombinant adenovirus: correlation with p53 functional status.

YKL-1, E1B 55 kDa-deleted recombinant adenovirus vector, capable of harboring a transgene casette of up to 4.9 kb, was newly constructed by reintroducing E1A and E1B 19 kDa into E1/E3-deleted adenoviral vector with a homologous recombination in E. coli. Virus replication and cytotoxicity were dramatically attenuated in all 3 different types of normal human cells. In contrast, YKL-1 efficiently replicated and induced cytotoxicity in most cancer cells, especially Hep3B and C33A cells with an inactivating p53 mutation. However, both H460 and HepG2 exhibited intermediate sensitivity to YKL-1, which was between that of Hep3B or C33A and normal human cells. The YKL-1 and DNA damaging agent, camptothecin effectively induced p53 in H460 and HepG2 as well as in normal cells. Furthermore, YKL-1 effectively prohibited both Hep3B and C33A tumor growth in nu/nu mice in a dose-dependent manner. H/E staining and TUNEL assay indicated a largely distributed necrotic area and apoptosis on its periphery. This study, therefore, indicates that YKL-1, possesses promising potential as an oncolytic adenoviral vector, which acts partially in a p53-dependent manner.

Adenoviridae↗
PubMed2000

Microsatellite marker panels for use in high-throughput genotyping of mouse crosses.

Several microsatellite genotyping panel sets have been developed that are polymorphic between C57BL/6J and CAST/Ei mice, or C57BL/6J and DBA/2J. One set of markers for each strain pair has an intermarker distance of approximately 20 cM, and a second set has an intermarker distance of 5 cM. The 20-cM set contains 105 markers for C57BL/6J x DBA/2J and 108 for C57BL/6J x CAST/Ei, divided into 13 panels. Each 5-cM set includes 350 markers arranged into 45 panels. A panel contains a number of primer pairs whose fluorescently labeled PCR products can be pooled together and separated on one lane of a polyacrylamide gel. The sets are arranged by the size of the PCR product and by the type of fluorescent dye; 5-cM sets are also arranged by chromosomal region. The 20-cM sets are most useful for full-genome scans, the 5-cM sets are useful for full-genome and/or for region-specific chromosome screens. Both sets were proven as useful tools for speed congenic development, quantitative trait loci (QTL) analysis and physical mapping. These panel sets provide a throughput of 1,536-2,304 mouse genotypes daily per one gel-based system. Whole genome scans of one animal require 13 or 48 gel lanes, with 20 cM or 5 cM density, respectively.

Animals↗
PubMed2000

Oxidized proteins in Alzheimer's plasma.

The levels of oxidatively modified proteins were examined in blood from Alzheimer's disease (AD) patients, non-AD controls, and AD relatives. Oxidative modification was measured by reacting the protein carbonyls with 2,4-dinitrophenyl hydrazine (DNPH). The total oxidized proteins were determined by HPLC, while specific protein oxidation was assessed from Western blots of electrophoretic gels using antibody to the DNP derivatives. Statistically significant elevations (P < 0.05) of total oxidized proteins were observed in both AD subjects and AD relatives when compared with non-AD controls. Moreover, a protein band (e.g., MW = 78-kDa) was uniquely oxidized in the plasma of AD subjects. Furthermore, this protein from AD subjects was more susceptible to in vitro oxidation. These data suggest that such oxidized proteins may be useful as biomarkers for the detection and evaluation of AD.

Aged↗