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Biomedical subjects

J Song

Publications and source records attributed to J Song.

At least 199 records · Page 11Linked to original sources
PubMed1999

The NS5A protein of hepatitis C virus partially inhibits the antiviral activity of interferon.

The non-structural protein 5A (NS5A) of some hepatitis C virus (HCV) isolates has been implicated in the inhibition of the antiviral activity of interferon (IFN). In the present study, the possible inhibitory effects of NS5A from two isolates of HCV subtype 1b, HCV-1bJk and M094AJk, and their chimeric form on the antiviral activity of IFN were examined. HCV-1bJk and M094AJk are categorized as IFN resistant and IFN sensitive, respectively, based on the sequences of the IFN-sensitivity determining region (ISDR). When encephalomyocarditis virus was used as a challenge virus, NS5A was shown to eliminate the antiviral activity of IFN, with inhibition being more prominent with HCV-1bJk NS5A than with M094AJk NS5A. Moreover, the inhibition was significantly weaker in cells expressing a chimeric NS5A that had a short stretch of 49 amino acids (aa 2209-2257), including the ISDR sequence, from M094AJk in the backbone of the HCV-1bJk sequence than in cells expressing the original NS5A from HCV-1bJk. These results suggest an important role for the 49 aa sequence, including the ISDR, in the inhibition of IFN-mediated antiviral activity. On the other hand, only a slight reduction of IFN antiviral activity by HCV-1bJk NS5A was observed when vesicular stomatitis virus was used as a challenge virus, and barely any reduction was observed when Japanese encephalitis virus was used. These results may reflect differential importance of each of the IFN-mediated signalling pathways in conferring resistance against different viruses.

3T3 Cells↗
PubMed1999

Rational type of laparoscopic hysterectomy and safety in anesthetic profiles.

OBJECTIVE: To evaluate what type of surgery would be more reasonable among 3 types of laparoscopic hysterectomy and to evaluate the safety of cardio-pulmonary changes on these patients during these operations. METHOD: A retrospective study was carried out in 215 women who underwent laparoscopic hysterectomy including laparoscopic-assisted vaginal hysterectomy (LAVH), laparoscopic hysterectomy (LH), total laparoscopic hysterectomy (TLH). Blood gas analysis, end-tidal CO2 levels and vital signs were checked and compared with control and preceding values. RESULTS: The average duration of operation was 102.5 min, 83.8 min and 118.3 min for LAVH (n = 97), LH (n = 75) and TLH (n = 43), respectively (p < 0.05). The average amount of bleeding was 297.5 ml, 152.3 ml and 149.2 ml for each type of hysterectomy, respectively. Hemoglobin decreased by an average of 1.6 g/100 ml, 0.9 g/100 ml and 0.8 g/100 ml, respectively. There was a lesser amount of bleeding for LH and TLH than for LAVH (p < 0.05). Profiles of blood gas analysis and expiratory CO2 varied significantly according to the operative stages under controlled anesthesia (p < 0.05), but were within the normal range. CONCLUSION: These results demonstrate that laparoscopic procedures advancing below the uterine vasculature can be considered effective for hysterectomies and that proper anesthesia can safely control the cardio-pulmonary changes during laparoscopic hysterectomy.

Adult↗
PubMed1999

PhhB, a Pseudomonas aeruginosa homolog of mammalian pterin 4a-carbinolamine dehydratase/DCoH, does not regulate expression of phenylalanine hydroxylase at the transcriptional level.

Pterin 4a-carbinolamine dehydratase is bifunctional in mammals. In addition to playing a catalytic role in pterin recycling in the cytoplasm, it plays a regulatory role in the nucleus, where it acts as a dimerization-cofactor component (called DCoH) for the transcriptional activator HNF-1alpha. A thus far unique operon in Pseudomonas aeruginosa contains a gene encoding a homolog (PhhB) of the regulatory dehydratase, together with genes encoding phenylalanine hydroxylase (PhhA) and aromatic aminotransferase (PhhC). Using complementation of tyrosine auxotrophy in Escherichia coli as a functional test, we have found that the in vivo function of PhhA requires PhhB. Strikingly, mammalian DCoH was an effective substitute for PhhB, and either one was effective in trans. Surprisingly, the required presence of PhhB for complementation did not reflect a critical positive regulatory effect of phhB on phhA expression. Rather, in the absence of PhhB, PhhA was found to be extremely toxic in E. coli, probably due to the nonenzymatic formation of 7-biopterin or a similar derivative. However, bacterial PhhB does appear to exert modest regulatory effects in addition to having a catalytic function. PhhB enhances the level of PhhA two- to threefold, as was demonstrated by gene inactivation of phhB in P. aeruginosa and by comparison of the levels of expression of PhhA in the presence and absence of PhhB in Escherichia coli. Experiments using constructs having transcriptional and translational fusions with a lacZ reporter indicated that PhhB activates PhhA at the posttranscriptional level. Regulation of PhhA and PhhB is semicoordinate; both PhhA and PhhB are induced coordinately in the presence of either L-tyrosine or L-phenylalanine, but PhhB exhibits a significant basal level of activity that is lacking for PhhA. Immunoprecipitation and affinity chromatography showed that PhhA and PhhB form a protein-protein complex.

Escherichia coli↗
PubMed1999

Categorizing asthma severity.

The National Asthma Education and Prevention Program (NAEPP) Expert Panel II recommended a stepped care pharmacotherapy approach to asthma treatment based on an objective assessment of asthma severity using daytime symptoms, nocturnal symptoms, and physiologic lung function. The worst grade of the individual variables determines overall asthma severity. With this approach, patterns of asthma severity categorization might vary among individual variables; one variable might have a predominant effect on overall categorization. During the run-in, pretreatment phase of five controlled clinical trials, data from 744 inhaled steroid nonusers and 685 inhaled steroid users on asthma control were collected and asthma severity categorized. In inhaled steroid nonusers nocturnal symptoms classified the majority of patients as severe, persistent, but wheeze classified 27.3% of patients as mild, intermittent and 25.7% as mild, persistent. If the worst grade from the four asthma symptoms was used for severity grading, most patients were categorized as severe, persistent. beta-Agonist use and FEV(1) classified most as moderate, persistent. There was poor correlation between variables in severity categorization. Severity grading for European patients was similar to that for U.S. patients. Applying the Expert Panel II recommended method for asthma severity categorization to a large data set illustrates that a single variable, nocturnal symptoms, determined to a large extent overall categorization. Development of a validated method for asthma severity categorization is essential for using a stepped care approach to asthma pharmacotherapy.

Administration, Inhalation↗
PubMed1999

The type I serine/threonine kinase receptor ActRIA (ALK2) is required for gastrulation of the mouse embryo.

ActRIA (or ALK2), one of the type I receptors of the transforming growth factor-beta (TGF-beta) superfamily, can bind both activin and bone morphogenetic proteins (BMPs) in conjunction with the activin and BMP type II receptors, respectively. In mice, ActRIA is expressed primarily in the extraembryonic visceral endoderm before gastrulation and later in both embryonic and extraembryonic cells during gastrulation. To elucidate its function in mouse development, we disrupted the transmembrane domain of ActRIA by gene targeting. We showed that embryos homozygous for the mutation were arrested at the early gastrulation stage, displaying abnormal visceral endoderm morphology and severe disruption of mesoderm formation. To determine in which germ layer ActRIA functions during gastrulation, we performed reciprocal chimera analyses. (1) Homozygous mutant ES cells injected into wild-type blastocysts were able to contribute to all three definitive germ layers in chimeric embryos. However, a high contribution of mutant ES cells in chimeras disrupted normal development at the early somite stage. (2) Consistent with ActRIA expression in the extraembryonic cells, wild-type ES cells failed to rescue the gastrulation defect in chimeras in which the extraembryonic ectoderm and visceral endoderm were derived from homozygous mutant blastocysts. Furthermore, expression of HNF4, a key visceral endoderm-specific transcription regulatory factor, was significantly reduced in the mutant embryos. Together, our results indicate that ActRIA in extraembryonic cells plays a major role in early gastrulation, whereas ActRIA function is also required in embryonic tissues during later development in mice.

Activin Receptors, Type I↗
PubMed1999

The risk groups for coronary heart disease in Koreans. Assessment by distribution of serum lipid concentrations.

Coronary heart disease is the most severe form of disease caused by atherosclerosis; and there is a strong relationship between serum lipid concentrations and atherosclerosis. By decade of life, means, standard deviations and selected percentiles were calculated according to sex for serum concentrations of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride in 69,563 Koreans. The prevalence of dyslipoproteinemias which were related to high risk of coronary heart disease were assessed. The mean concentrations of serum total cholesterol and LDL-C in the Korean population were 5.02 mmol/l and 3.00 mmol/l. The 75th and 90th percentile concentrations of total cholesterol were 5.59 mmol/l and 6.24 mmol/l. The mean concentrations of serum triglyceride and HDL-C were 1.58 mmol/l and 1.30 mmol/l. The hyperlipoproteinemia type IV (4.8%) was the most frequent, followed by Type IIa (4.6%), hypoalphalipoproteinemia (3.3%), and type IIb (0.2%). According to the National Cholesterol Education Program Adult Treatment Panel II, 4.1% of Korean adults needed the initial drug therapy and 10.8% the initial dietary therapy for hypercholesterolemia. The age and sex-specific treatment guidelines for hypercholesterolemia would make it possible that early intervention could be applied to atherosclerosis in Korean adults.

Adolescent↗
PubMed1999

Removal of petrous apex meningioma and microvascular decompression for trigeminal neuralgia through the anterior petrosal approach. Case report.

A 64-year-old female presented with right trigeminal neuralgia. Computed tomography and magnetic resonance (MR) imaging demonstrated a tumor attached to the right petrous apex. MR imaging also revealed that the trigeminal nerve was compressed and distorted by the tumor. Tumor removal and microvascular decompression (MVD) were performed via the anterior petrosal approach. The trigeminal nerve was distorted by the tumor and the superior cerebellar artery compressed the medial part of the root entry zone of the trigeminal nerve. The surgery resulted in complete relief of the trigeminal neuralgia. Posterior fossa tumors causing ipsilateral trigeminal neuralgia are not rare, and are often removed via the suboccipital retromastoid approach, as MVD for trigeminal neuralgia is usually performed through the retromastoid approach. The advantages of the anterior petrosal approach are shorter access to the lesion and direct exposure without interference from the cranial nerves, and that bleeding from the tumors is easily controlled as the feeding arteries can be managed in the early stage of the surgery. We conclude that the anterior petrosal approach is safe and advantageous for the removal of petrous apex tumor associated with trigeminal neuralgia.

Female↗
PubMed1999

Effects of smoking and maturation on long-term maintenance of lumbar spinal fusion success.

This is a follow-up study of a multicenter, randomized, placebo-controlled clinical trial conducted in accordance with the condition for Food and Drug Administration approval for pulsed electromagnetic fields. The purpose of this study was to evaluate the long-term efficacy and safety of pulsed electromagnetic fields for spinal fusion. An earlier clinical trial study was conducted to evaluate the efficacy of Pulsed Electromagnetic Fields to enhance fusion success at one year follow-up. In the original study, 195 patients undergoing interbody fusion were enrolled. Of the 195 patients, 98 were in the active group and 97 were in the placebo group. Study results showed a 92% successful fusion rate in the active group compared to 68% in the placebo group. For this long-term follow-up study, all patients who had healed in the original study were recalled for a follow-up radiograph. Radiographs were assessed by the attending surgeon for fusion assessment, when possible. The results of this long-term follow-up study showed that there was a reduction in maintenance of the fusion over time by 25%, but that the reduction was unrelated to treatment group and correlated statistically with whether the patient was a smoker.

Adult↗
PubMed1999

[The correlation between integration of HBV X, S, Pre-S, C gene and the expression of oncogenes/tumor suppressor genes in primary hepatocellular carcinoma].

OBJECTIVE: To study the relation between the integration of HBV X, S, Pre-S and C genes and the expression of oncogenes/tumor suppressor genes in hepatocellular carcinoma(HCC). METHODS: To prepare the Dig-HBV probes with random priming method, to detect the existing status of HBV DNA and the integration rates of HBV X, S, Pre-S and C genes by Southern blot and dot blot hybridization, and to examine the expression of oncogenes and tumor suppressor genes by immunohistochemistry in HCC. RESULTS: The integration rates of HBV X, S, Pre-S and C genes in HCC were 87.5%(28/32), 62.5% (20/32), 62.5%(20/32) and 25.0%(8/32), respectively. The expression rates of p62myc, p21ras, p53 and p16 proteins were 81.2%(26/32), 50.0%(16/32), 43.8%(14/32), and 31.3(10/32), respectively. Statistical analysis showed that the expression of p62myc, p21ras and variant p53 proteins was obviously higher in HCC group with X gene than in free-X gene HCC group and that the expression of p62myc protein was obviously higher in HCC group with Pre-S gene than in free-Pre-S HCC group. CONCLUSION: The integration of HBV X or Pre-S gene with cellular chromosome can activate myc, ras oncogenes and inactivate the p53 tumor suppressor gene.

Carcinoma, Hepatocellular↗
PubMed1999

Toxicology of intrahepatic arterial administration of interventional phosphorus-32 glass microspheres to domestic pigs.

OBJECTIVE: To evaluate the toxic response to intrahepatic arterial administration of radioactive phosphorus-32 glass microspheres (32P-GMS) in domestic pigs. METHODS: Through selective catheterization of hepatic artery, 32P-GMS was infused to 5 healthy domestic pigs in a dosage equivalent to the therapeutic dose for human being, and 31P-GMS was infused to other 5 healthy domestic pigs. Two pigs served as the whole course blank controls. One pig from each group was surrendered to euthanasia at week 1, 2, 4, 8 and 16, respectively, and liver biopsies were performed on the rest of pigs at the corresponding time points. Liver tissues from different sites were taken for light and electron microscopy. The ultrastructural histopathological changes were evaluated semiquantitatively. RESULTS: The accumulative amount of 32P-GMS in the target tissue attained more than 90% of the total dose administrated. Histologically, abnormal hepatocytes were easily found at week 1 or 2. At week 4 they were less than at week 1 or 2, and endothelium of the sinuses were damaged prominently. At week 8 they were scarcely seen, and liver tissue recovered gradually. The histological features of liver tissue restored to normal at week 16. Semiquantitative analysis of ultrastructural morphology in the experimental group showed no statistical difference (P > 0.50) between the nuclear abnormality (Nabn) and mitochrondrial variability (Mvar) at week 1 or 2, but revealed prominent difference (P < 0.01, P < 0.001) as compared with those in other groups. In the experimental group the Nabn in tissues showed no significant difference (P > 0.20) between week 8 and week 16. CONCLUSION: 32P-GMS internal irradiation at the dosage equivalent to human therapeutic dosage exerts reversible injury to domestic pig liver tissue, and it takes more than 8 weeks for the injured liver tissue to recover.

Animals↗
PubMed1999

Relationship of beta-glucuronidase to differentiation and invasion of human colorectal carcinoma.

OBJECTIVE: To investigate the relationship between beta-glucuronidase and tumor differentiation and invasion in human colorectal carcinoma. METHODS: The expression of beta-glucuronidase in human colorectal carcinoma tissue was determined by streptavidin-peroxidase immunohistochemical method. Four human colorectal carcinoma cell lines were analysed for beta-glucuronidase in the medium by spectrophotometry method. RESULTS: Compared with well differentiated colorectal carcinomas, beta-glucuronidase expression was higher in poorly differentiated tumors. An association was found between beta-glucuronidase overexpression in colorectal carcinoma and more advanced tumor Dukes' stage (P < 0.05). With increasing maximum depth of invasion, tumors more frequently show higher beta-glucuronidase expression (P < 0.05). The analysis of colorectal carcinoma cell lines for beta-glucuronidase showed that low levels of beta-glucuronidase (activity range, 1.29 to 1.96 micrograms/10(6) cells per hour) were associated with the well differentiated cell lines which have low invasiveness (CX1, CCL187), and this was in contrast to the elevated level of the enzyme (2.46 to 2.73 micrograms/10(6) cells per hour) present in the medium derived from the poorly differentiated cells with high invasiveness (CCLI227, CCL228) (P < 0.05). CONCLUSIONS: Poorly differentiated human colorectal carcinoma cells could synthesize more beta-glucuronidase, enhance local invasion. Immunohistochemical staining for beta-glucuronidase might be helpful to diagnosing the differentiation degree and invasiveness of human colorectal carcinomas, and the secreted beta-glucuronidase might provide a useful measurement of the differentiation degree and invasiveness of cultured human colorectal carcinoma cells.

Adult↗
PubMed1999

[The percentage of free prostate specific antigen used in detecting prostate cancer].

OBJECTIVE: To evaluate the value of the percentage of free prostate specific antigen in detecting prostate cancer. METHODS: Serum free prostate specific antigen (F-PSA) and total PSA were measured with immunoradiometric assay, and the free/total PSA ratio was calculated. In 117 patients, 31 had prostate carcinoma and 86 BPH. RESULTS: The free/total PSA ratio was lower in patients with prostate cancer than in those with BPH. If the total serum PSA level was limited with in 4 - 10 ng/ml, the free/total PSA ratio can be used in the differential diagnosis of prostate cancer and BPH except total PSA. CONCLUSIONS: The free/total PSA ratio can be used in the differential diagnosis of prostate cancer and BPH, especially when serum PSA level is limited with in 4 - 10 ng/ml.

Aged↗