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Biomedical subjects

S K Kang

Publications and source records attributed to S K Kang.

At least 73 records · Page 4Linked to original sources
PubMed2000

Investigation of the stability of hardened slag paste for the stabilization/solidification of wastes containing heavy metal ions.

We have studied the effect of chromium ions and lead ions on the chemical stability of hardened slag paste with toxic wastes during the stabilization/solidification process. The influences of Cr and Pb ions on the hydration of slag were also investigated. Sodium silicate (Na(2)SiO(3)), 5 wt.% of slag, was used as an alkali activator for slag hydration. The physical stability of hardened paste containing partial replacement of slag with fly ash and gypsum was also examined. When gypsum was added to slag, the compressive strength of hardened slag paste developed, accompanying the activation of alumino-ferrite-tricalciumsulfate (Al(2)O(3)-Fe(2)O(3)-3CaSO(4), AFt) and alumino-ferrite-monocalciumsulfate (Al(2)O(3)-Fe(2)O(3)-CaSO(4), AFm) phase generation. Those phases caused densification of the microstructure. Concurrently, the leaching amount of heavy metal ions was decreased. When fly ash was added to slag, the compressive strength increased and the leaching amount decreased with both active formation of aluminate hydrates and ion substitution. Lead ions were mostly stabilized through physical encapsulation by the hardened slag paste's hydrate matrix. In the case of chromium ions, we observed that it was mainly solidified through the formation of a substitutional solid solution with aluminum atoms in the structure of aluminate hydrates.

Alkalies↗
PubMed2000

Differential expression of human gonadotropin-releasing hormone receptor gene in pituitary and ovarian cells.

In terms of regulation of gene expression, gonadotropin-releasing hormone receptor (GnRHR) found in extrapituitary tissues has been suggested to be different from that in the pituitary. In the present study, we examined the molecular basis of this difference using the pituitary alphaT3-1 and ovarian carcinoma OVCAR-3 cells. As a first step, the different expression levels of GnRHR mRNA in the pituitary and ovarian cells were investigated using semi-quantitative RT-PCR. Quantitative analysis showed that the expression level of hGnRHR is a nine-fold higher in primary pituitary tissues than the primary culture of ovarian carcinomas (PCO). In pituitary alphaT3-1 cells, the expression level of hGnRHR was ten-fold higher than ovarian carcinoma OVCAR-3 cells. The possibility of the differential use of various cell-specific promoters in different cells was addressed by transiently transfecting cells with 3'-deletion clones of human GnRHR promoter. Sequential deletion of the 5'-flanking region of the gene revealed the use of two putative promoters, designated PR1 (-771 to -557) and PR2 (-1351 to -1022), and a negative control region (-1022 to -771), in the pituitary and ovarian cells. The same promoters appeared to be utilized for driving the basal promoter activities in both alphaT3-1 and OVCAR-3 cells, suggesting that there is no cell-specific promoter usage for the human GnRHR gene. Alternatively, the involvement of different regulatory protein factors was investigated using electrophoretic gel mobility shift assays. When end-labeled PR1 was used as a probe, two unique shifted complexes were identified in OVCAR-3 cells when compared to alphaT3-1 cells. One unique protein-DNA complex was observed in alphaT3-1 cells compared to OVCAR-3 cells when incubated with end-labeled PR2 as a probe. These DNA-protein complexes appeared to be specific, as they competed with excess amount of unlabelled competitor PR1 and PR2, respectively. In summary, it is unlikely that the use of a cell-specific promoter contributes to the different characteristics of ovarian GnRHR. Our study demonstrates that one mechanism by which cell-specific expression of human GnRHR is achieved is through the binding of distinct and/or combinations of cell-specific regulatory factors to various promoter elements in the 5'-flanking region of the gene.

Animals↗
PubMed2000

Biological monitoring of occupational exposure to N,N-dimethylformamide--the effects of co-exposure to toluene or dermal exposure.

OBJECTIVES: The objective of this study is to assess the exposure and intake dose of N,N-dimethylformamide (DMF) and the correlation between them, according to the type of exposure for the workers in the DMF industry. METHODS: We monitored 345 workers occupationally exposed to DMF, from 15 workshops in the synthetic fiber, fiber coating, synthetic leather and paint manufacturing industries. Ambient monitoring was carried out with personal samplers to monitor the external exposure. Biological monitoring was done to determine the internal dose by analyzing N-methylformamide (NMF) in end-shift urine. Work procedure and exposure type of each DMF workshop was carefully surveyed, to classify workers by exposure type according to work details. Workers were classified into three groups (Group A: continuous and direct exposure through inhalation and skin; Group B: intermittent and short-term exposure through inhalation and skin; Group C: continuous and indirect exposure mostly through inhalation). RESULTS: Geometric mean of DMF concentration in air was 2.62 (GSD 5.30) ppm and that of NMF in urine was 14.50 (GSD 3.89) mg/l. In the case of continuous absorption through inhalation and dermal exposure (Group A), the value of NMF in urine corresponding to 10 ppm of DMF was 45.3 mg/l (r = 0.524, n = 178), 39.1 mg/g creatinine (r = 0.424), while it was 37.7 mg/l (r = 0.788, n = 37), 24.2 mg/g creatinine (r = 0.743) in the case of absorption mostly through inhalation (Group C). Creatinine correction reduced the correlation between two parameters. CONCLUSION: The NMF in urine corresponding to 10 ppm DMF, of the dermal and inhalation exposure group was 39.1 mg/g creatinine (r = 0.424, n = 178), while that of the inhalation exposure-only group was 24.2 mg/g creatinine (r = 0.743, n = 37). Co-exposure with toluene reduced the NMF excretion in urine.

Air Pollutants↗
PubMed2000

High-level expression of canine parvovirus VP2 using Bombyx mori nucleopolyhedrovirus vector.

For the potential use as recombinant vaccine, canine parvovirus (CPV) major capsid protein VP2 was expressed using Bombyx mori nucleopolyhedrovirus (BmNPV) vector. CPV VP2 gene was introduced into polyhedrin-based BmNPV transfer vector pBmKSK3, and recombinant virus BmK1-Parvo was prepared. When anti-CPV.VP2 monoclonal antibody was employed in immunofluorescence staining, an intense signal was observed within BmK1-Parvo-infected Bm5 cells but not within uninfected cells or cells infected with a wild-type BmNPV-K1. In hemagglutination assay, the expression level of VP2 were 3.2 x 10(3) HA units/ml from infected Bm5 cells, 2.1x 10(5) HA units/larvae from infected larval fat body, and 1.6x 10(6) HA units/ml from infected larval hemolymph. These results suggested that BmNPV vector system using B. mori larva as host could be applied to efficient mass-production of recombinant vaccines.

Animals↗
PubMed2000

Characterization of four isolates of Bombyx mori nucleopolyhedrovirus.

Bombyx mori nucleopolyhedroviruses (BmNPVs), isolated from a sericultural Korean farm, were purified and characterized by their DNA restriction pattern, virus replication, polyhedra production and gene structures. The EcoR I and Sal I fragments showed similar overall patterns with minor difference but distinguishable patterns in each isolate. There was no significant difference in the virus replication pattern, yield of total polyhedra production and polyhedra morphology, but the yield of released polyhedra by BmNPV-K1 in Bm5 cells was 2 to 5 times higher than that of other isolates. In comparative studies of p10 gene, BmNPV-K1 and K3 had same structure and they encoded a protein consisting of 94 amino acids. Although BmNPV-K2 encoded the same length of amino acids with BmNPV-K1 and K3, it had different structure, and BmNPV-K4 had the p10 gene encoding 70 amino acids.

Amino Acid Sequence↗
PubMed2000

The short-term changes of bone mineral metabolism following bone marrow transplantation.

Organ transplantation is now the treatment of choice for many patients with life-threatening chronic diseases. A new set of side effects unique to these groups of patients has become recognized, and bone disease is one of these complications. However, little is known about the effects of myeloablative treatment followed by bone marrow transplantation (BMT) on bone mineral metabolism. We have prospectively investigated 31 patients undergoing BMT for hematologic diseases. Serum concentrations of calcium, phosphorus, creatinine, gonadotropins, sex hormones, and the biochemical markers of bone turnover were measured. The samples were collected before BMT and 1, 2, 3, 4, and 12 weeks, 6 months, and 1 year after BMT. Bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry before BMT and 1 year after BMT. The serum carboxy-terminal cross-linked telopeptide of type I collagen increased progressively until 4 weeks after BMT. Thereafter, it began to decrease and reached basal values after 1 year. Serum osteocalcin decreased progressively until 3 weeks after BMT. After that, it increased and reached basal values after 3 months. No distinct differences were observed in the serum biochemical turnover markers between males and females, or between patients who received total body irradiation and those who did not. One year after BMT, lumbar spine BMD had decreased by 2.2%, and total proximal femoral BMD had decreased by 6.2%. Eighty-six percent of the women (12/14) went into a menopausal state immediately after BMT. This was caused by high gonadotropin levels and low estradiol levels. In contrast, gonadotropin levels and testosterone levels did not change significantly in the male patients after BMT. In conclusion, the rapid impairment of bone formation and the increase in bone resorption, as shown by the biochemical markers in this study, might play a role in post-BMT bone loss.

Adolescent↗
PubMed2000

Effect of bee venom and its melittin on apical transporters of renal proximal tubule cells.

Renal failure by bee venom may be related to a malfunction of renal transporters. However, the effects of bee venom on apical membrane transporters of renal proximal tubular cells are not yet known. The aim of this study was to examine the effects of dried bee venom of Apis mellifera and its melittin on apical transporter activity of primary cultured rabbit kidney proximal tubule cells. Bee venom (1 microg/ml) decreased the cell viability and increased lactate dehydrogenase activity over 30-min treatments. Its effect was blocked by mepacrine or AACOCF(3) (10(-6) M; phospholipase A(2) inhibitors). However, there was no effect on cell viability at a concentration of 0.01 microg/ml of bee venom. Thus, we investigated the effect of bee venom (1 microg/ml) on the activity of renal transporters at 30 min. Bee venom inhibited alpha-methyl-D-glucopyranoside, Pi, and Na(+) uptakes, but increased Ca(2+) uptake. These effects of bee venom were blocked by mepacrine or AACOCF(3) (10(-6) M), and bee venom-induced stimulation of Ca(2+) uptake was also blocked by methoxyverapamil and nifedipine (L-type calcium channel blockers). In addition, bee venom increased [(3)H]-arachidonic acid release by 216 % of that of control. In all experiments, bee venom melittin (0.5 microg/ml) had an identical effect to that of bee venom itself. In conclusion, bee venom inhibited, in part, alpha-MG, Pi, and Na(+) uptakes through its melittin which increased Ca(2+) uptake and arachidonic acid release in primary cultured rabbit renal proximal tubule cells.

Animals↗
PubMed2000

Role of gonadotropin-releasing hormone as an autocrine growth factor in human ovarian surface epithelium.

Epithelial ovarian cancer, which accounts for 80-90% of all ovarian cancers, is the most common cause of death from gynecological malignancies and is believed to originate from the ovarian surface epithelium. In the present study we investigated the expression of GnRH and its receptor in human ovarian surface epithelial (hOSE) cells and provided novel evidence that GnRH may have antiproliferative effects in this tissue. Using RT-PCR and Southern blot analysis, we cloned the GnRH and GnRH receptor (GnRHR) in hOSE cells. Sequence analysis revealed that GnRH and its receptor have sequences identical to those found in the hypothalamus and pituitary, respectively. To address whether GnRH regulates its own and receptor messenger RNA (mRNA), the cells were treated with different concentrations of the GnRH agonist (D-Ala6)-GnRH. Expression levels of GnRH and its receptor were investigated using quantitative and competitive RT-PCR, respectively. Interestingly, a biphasic effect was observed for the GnRH and GnRHR mRNA levels. High concentrations of the GnRH agonist (10(-7) and 10(-9) M) decreased GnRH and GnRHR mRNA levels, whereas a low concentration (10(-11) M) resulted in up-regulation of GnRH and receptor mRNA levels. Treatment with the GnRH antagonist, antide, prevented the biphasic effects of the GnRH agonist in hOSE cells, confirming the specificity of the response. Furthermore, to investigate the physiological significance, we studied receptor-mediated growth regulatory effects of GnRH in human ovarian surface epithelial cells. The cells were treated with GnRH analogs, and the proliferative index of cells was measured using a [3H]thymidine incorporation assay. (D-Ala6)-GnRH had a direct inhibitory effect on the growth of hOSE cells in a time- and dose-dependent manner. This antiproliferative effect of the GnRH agonist was receptor mediated, as cotreatment of hOSE cells with antide abolished the growth inhibitory effects of the GnRH agonist. The results strongly suggest that GnRH can act as an autocrine/paracrine regulator in hOSE cells.

Autocrine Communication↗
PubMed2000

Transcriptional down-regulation of human gonadotropin-releasing hormone (GnRH) receptor gene by GnRH: role of protein kinase C and activating protein 1.

Clinical applications of GnRH agonists (GnRHa) are based primarily on the decrease in gonadotropin release after down-regulation of the GnRH receptor (GnRHR) by continuous GnRHa administration. However, the molecular mechanisms underlying the transcriptional regulation of the human GnRHR gene after prolonged GnRH treatment remain poorly understood. In the present study GnRHa-mediated regulation of human GnRHR gene transcription was studied by transiently transfecting the mouse gonadotrope-derived (alphaT3-1) cells with a 2297-bp human GnRHR promoter-luciferase construct (p2300-LucF). A dose- and time-dependent decrease in human GnRHR promoter activity was observed after GnRHa treatment. An average 71% decrease in promoter activity was observed after 24-h treatment with 0.1 microM GnRHa, which was blocked by cotreatment of the GnRH antagonist, antide. This effect was mimicked by phorbol 12-myristate 13-acetate (TPA) administration. In addition, the GnRHa- and TPA-mediated decrease in the human GnRHR promoter activity was reversed by a specific protein kinase C (PKC) inhibitor, GF109203X, or depletion of PKC by TPA pretreatment. These findings indicate that the activation of the PKC pathway is important in regulating the human GnRHR gene expression. By progressive 5'-deletion studies, we have identified a 248-bp DNA fragment (-1018 to -771, relative to the translation start site) at the 5'-flanking region of the human GnRHR gene that is responsible for the GnRHa-mediated down-regulation of human GnRHR promoter activity. Analysis of this sequence reveals the existence of two putative activating protein-1 (AP-1) sites with 87% homology to the consensus sequence (5'-TGA(G/C)T(C/A)A-3'), located at -1000 to -994 (5'-TTAGACA-3', in complementary orientation) and -943 to 937 (5'-TGAATAA-3'). Using competitive gel mobility shift assays, AP-1 binding was observed within this 248-bp region. Site-directed mutation of the putative AP-1-binding site located at -1000 to -994 abolished the GnRHa-induced inhibition. Further competitive GMSA and supershift experiments confirmed the identity of AP-1 binding in this region. By the use of Western blot analysis, a significant increase in c-Jun (100%; P < 0.05) and c-Fos (50%; P < 0.05) protein levels was observed after GnRHa treatment in alphaT3-1 cells. In addition, our data suggested that a change in AP-1 composition, particularly c-Fos, was important in mediating GnRHa-induced inhibition of human GnRHR gene expression. We conclude that activation of the PKC pathway by GnRH is important in controlling human GnRHR gene expression. In addition, the putative AP-1-binding site located at -1000 to -994 of the human GnRHR5'-flanking region has been functionally identified to be involved in mediating this down-regulatory effect.

Animals↗
PubMed2000

Regulation of gonadotropin-releasing hormone and its receptor gene expression by 17beta-estradiol in cultured human granulosa-luteal cells.

There is evidence that GnRH and its binding sites are expressed in numerous extrapituitary tissues, including the primate ovary. However, the factors that regulate ovarian GnRH and its receptor (GnRH-R) remain poorly characterized. Since gonadal steroids are key regulators of ovarian functions, the present study investigated the role of 17beta-estradiol (E2) in regulating GnRH and GnRH-R messenger RNA (mRNA) from human granulosa-luteal cells (hGLCs). RT-PCR was used to isolate the ovarian GnRH-R transcript equivalent to the full-length coding region in the pituitary from hGLCs. Sequence analysis revealed that the ovarian GnRH-R mRNA is identical to its pituitary counterpart. Basal expression studies indicated that GnRH and GnRH-R mRNA levels significantly increased with time in vitro, reaching levels of 160% and 170% on day 8 and 10 of culture, respectively (P < 0.05). Treatment with various concentrations of estradiol (1-100 nM) for 24 h resulted in a dose-dependent decrease (P < 0.05) in GnRH and GnRH-R mRNA levels. Time course studies indicated that short-term treatment (6 h) with E2 (1 nM) had no significant effect on GnRH mRNA levels, while long-term treatment (48 h) with E2 resulted in a 40% decrease (P < 0.001) in GnRH mRNA levels. In contrast, GnRH-R mRNA levels exhibited a biphasic pattern, such that a short-term treatment (6 h) with E2 increased GnRH-R mRNA levels by 20% (P < 0.05), whereas long-term treatment (48 h) resulted in a 60% decrease (P < 0.001) in GnRH-R expression in hGLCs. Cotreatment of estradiol and tamoxifen blocked the E2 induced-regulation of GnRH and its receptor mRNAs, indicating that the E2 effect was mediated through its receptor. In summary, our studies demonstrate that the ovary possesses an intrinsic GnRH axis that is regulated during luteinization in vitro, and that E2 is capable of regulating GnRH and its receptor in the human ovary.

Cells, Cultured↗
PubMed2000

Expression and regulation of P2U-purinergic receptor in human granulosa-luteal cells.

The P2U purinoceptor (P2UR) has been identified pharmacologically in the ovary. However, the expression and regulation of the P2UR messenger RNA (mRNA) in human ovarian cells are still poorly characterized. The present study was designed to examine the expression and regulation of the P2UR in human granulosa-luteal cells (hGLCs) by RT-PCR and Northern blot analysis. A PCR product corresponding to the expected 599-bp P2UR complementary DNA was obtained from hGLCs. Molecular cloning and sequencing of the PCR product revealed an identical sequence to the reported P2UR complementary DNA. Two mRNA transcripts of 2.0 kb and 4.6 kb were identified in hGLCs using Northern blot analysis. The expression of the P2UR mRNA was down-regulated by human CG in a dose- and time-dependent manner. Treatment with 8-bromo-cAMP and forskolin also attenuated P2UR mRNA levels. Calcium signaling following the activation of the P2UR in single hGLCs was studied using microspectrofluorimetry. It revealed that, like ATP, uridine triphosphate (UTP) also induced cytosolic calcium mobilization in a dose-dependent manner. These results demonstrate for the first time that the P2UR mRNA is expressed in hGLCs and that P2UR mRNA is regulated by human CG, cAMP, and forskolin. The P2UR expressed in hGLCs functional because activation of the P2UR by ATP or UTP resulted in rapid and transient mobilization of cytosolic calcium at the single cell level. These findings further support a potential role of this neurotransmitter receptor in the human ovary.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2000

Autocrine role of gonadotropin-releasing hormone and its receptor in ovarian cancer cell growth.

We have recently proposed an autocrine role of gonadotropin-releasing hormone (GnRH) and its receptor (GnRH-R) in human ovarian surface epithelium. In the present study, we examine the presence and role of a GnRH/GnRH-R loop in epithelial ovarian cancer cells, OVCAR-3. A dose-dependent biphasic response in GnRH and GnRH-R mRNA levels were observed after treating with GnRH agonist [GnRHa, (D-Ala6)-GnRH], for 24 h. High concentrations of GnRHa (10(-9) M and 10(-7)) decreased the GnRH and GnRH-R mRNA levels, whereas a low concentration (10(-11) M) resulted in an upregulation of GnRH and GnRH-R genes expression. Cotretment with the competitive antagonist, antide, prevented the biphasic effect induced by GnRHa, confirming the specificity of the response. In addition, GnRHa treatment resulted in a time- and dose-dependent inhibition on OVCAR-3 cells growth. A significant inhibition of proliferation was detected as early as the d 2 of treatment. Treatment with 10(-7) M GnRHa induced DNA fragmentation in OVCAR-3 cells, suggesting that the GnRHa-induced antiproliferation in OVCAR-3 cells was mediated by apoptosis. Again, this effect was prevented by cotreatment of antide. Taken together, our findings strongly support the notion that GnRH acts as an autocrine/paracrine regulator of ovarian cancer cell proliferation.

Apoptosis↗
PubMed2000

New ADA criteria in the Korean population: fasting blood glucose is not enough for diagnosis of mild diabetes especially in the elderly.

BACKGROUND: To compare the 1997 American Diabetes Association (ADA) criteria with the 1985 World Health Organization (WHO) criteria in categorization of the diabetes diagnostic status of Koreans and to define clinical characteristics of subjects diagnosed differently by the two criteria. METHODS: In 810 Korean subjects, we analyzed blood glucose and insulin response during 75 g oral glucose tolerance test (OGTT). According to current WHO criteria, the cutoff values of FPG which distinguish normal and IGT from diabetes were determined. Then the subjects were categorized according to both WHO and ADA criteria. The clinical characteristics of the subjects with different diagnostic categories by the two criteria were defined. RESULTS: The FPG cut point distinguishing diabetes from IGT was 117 mg/dl, and from normal was 110 mg/dl. The overall agreement between the ADA criteria and the WHO criteria was moderate, as reflected in the kappa of 0.45. 141 of subjects categorized diabetes by WHO criteria were not diagnosed with ADA criteria. These discordant subjects were older in age and showed blunted early insulin response than concordant normal subjects. CONCLUSION: These results suggest that mild diabetes by the WHO criteria, especially in the elderly, would not be diagnosed as diabetes by the ADA FPG criteria only. Thus, in a group at high risk for developing diabetes or in a relatively older age group, we should continue using the OGTT.

Adolescent↗
PubMed2000

The applicability of WHO-NCTB in Korea.

Neurotoxic chemical substances have been widely used in Korea since 1960. The World Health Organization-recommended Neurobehavioral Core Test Battery (WHO-NCTB) was introduced into Korea early in the 1990s and has been applied to the study of workers exposed to neurotoxic chemicals. Thirteen studies using the WHO-NCTB have been reported in Korean journals, two of which were published in English and the rest in Korean-language journals. Ten studies were reviewed to examine the influence of age, education and other factors on the WHO-NCTB in Korean workers. Pursuit Aiming, Digit Symbol, Digit Span and Benton Visual Retention test are effected by years of education, especially when years of education were less than 12. Santa Ana Dexterity test and Simple Reaction Time test were not effected. Pursuit Aiming, Santa Ana Dexterity test and Digit Symbol were effected by age, but not the Simple Reaction Time test, Benton Visual Retention test, or Digit Span. Some studies had difficulty in finding a proper reference group, because many workers exposed to neurotoxic chemicals were old and less educated than available reference groups. However, daily use of chopsticks by Koreans, especially coupled with work that requires skillful and quick hand movements, might develop psychomotor functions in exposed workers. The cultural and emotional differences between Korean and Caucasian led POMS to be applied only to two studies. In conclusion, the WHO-NCTB has been successfully applied to Korean workers for evaluating the neurobehavioral effects of individual chemicals, although age and education can be confounding factors. It was difficult to apply the WHO-NCTB to workers educated less than 12 years.

Affect↗
PubMed2000

Lessons learned--15 years of the WHO-NCTB: a review.

Based on expert recommendations, the World Health Organization (WHO) recommended the Neurobehavioral Core Test Battery (NCTB) in 1983 to detect neurotoxicity in world-wide populations. The NCTB consists of 7 neurobehavioral tests (Digit Symbol, Digit Span, Benton visual memory test/recognition form, Santa Ana dexterity test, Simple Reaction Time, Pursuit Aiming II, and Profile of Mood States). Research with the NCTB provides the context for the results of a mini-symposium held in 1999 to discuss the lessons learned about using the NCTB in working populations. Speakers from Africa, Asia, Europe, and North America reviewed data from 94 studies using the NCTB, including 63 from China, 13 from Korea, 11 from Poland, three from South Africa, three from the USA, and one from Ecuador. Although a consensus was not sought in the symposium, the key lessons learned that emerged from the various presentations, were: * The NCTB is effective in testing adults with 12 or more years of formal education, but can not reliably test persons with less than 9 years of education. * People from cultures very different from those in Europe and North America (eg, aboriginal and African cultures) may not be tested effectively by the NCTB, although others such as at least some Asian populations, can be. To address this problem, the construct validity of the NCTB should be established in a wide range of countries. * The POMS measures of emotion proved to be very sensitive to neurotoxic exposures in several countries, but the POMS was the NCTB test most affected by cultural differences. The Digit Symbol or the Milan modification of that test was also highly sensitive to neurotoxic exposures. * Examiner drift following training to administer the NCTB is a significant problem in technically trained Examiners. Pursuit Aiming II is very difficult to score reliably.

Adult↗
PubMed1999

Development of a novel expression vector system using Spodoptera exigua nucleopolyhedrovirus.

To develop a novel Spodoptera exigua nucleopolyhedrovirus (SeNPV) expression vector system, we examined characteristics of the SeNPV polyhedrin expression in S. exigua cells (Se301). While the extracellular virus titer of SeNPV was 100-fold lower than that of Autographa californica nucleopolyhedrovirus (AcNPV), the levels of polyhedral inclusion body (PIB) formation and polyhedrin expression were higher in SeNPV. To investigate foreign gene expression under the control of the polyhedrin promoter, polyhedrin-based transfer vector pSeKSK2 was constructed, and then recombinant virus SeK1-LacZ was constructed by inserting E. coli lacZ gene as a reporter gene into a genomic DNA of SeNPV using this transfer vector. The beta-Galactosidase activity of SeK1-LacZ in Se301 was about 1.3 times higher than that of BacPAK6. Thus, the SeNPV expression vector system constructed in this study would be very useful in the expression of foreign proteins, specifically for the enhancement of the pesticidal properties of SeNPV by inserting pesticidal genes.

Animals↗