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Biomedical subjects

D Y Kim

Publications and source records attributed to D Y Kim.

At least 163 records · Page 9Linked to original sources
PubMed1999

Detection of methylation damage in DNA of gastric cancer tissues using 32P postlabelling assay.

Gastric cancer is the most common cancer in Korea. The causes are still unknown but it has been speculated that gastric cancer is associated with consumption of foods rich in nitrates/nitrites or a high dietary intake of salt or pickled food. In the present study, we studied the level of alkylated DNA adducts formed in gastric cancer tissues in comparison with that in normal gastric mucosa. DNA was extracted from surgically removed gastric cancer tissues and patient-matched normal gastric mucosa. The level of N7-methyldeoxyguanosine was measured by 32P-postlabelling assay after high performance liquid chromatography (HPLC) enrichment. We found that the level of N7-methyldeoxyguanosine of gastric cancerous tissues was significantly higher than that of normal gastric mucosa (P=0.01685).

Adenocarcinoma↗
PubMed1999

Fatal measles virus infection in Japanese macaques (Macaca fuscata).

An outbreak of natural measles virus infection occurred in a group of Japanese macaques (Macaca fuscata). Over a period of 4 months, 12 of 53 Japanese macaques died following a 2-23-day history of anorexia, diarrhea, and dermatitis. The monkeys were kept in outdoor exhibits but had been moved temporarily into indoor caging and then transferred to new outdoor exhibits. Ten monkeys died while they were in temporary caging, and two monkeys died after they were moved to new outdoor exhibits. The diagnoses were made based on the results of histopathology, immunohistochemistry (IHC), in situ hybridization (ISH), and electron microscopy. Measles virus antigens were detected in the lung, stomach, skin, salivary gland, spleen, and lymph nodes. Tangled, tubular nucleocapsids compatible with paramyxovirus were noted in the lung tissue. As a result of immunosuppression following measles virus infection, various secondary infections including disseminated cytomegalovirus infection, adenoviral and bacterial pneumonia, and Candida albicans-associated gingivitis and esophagitis were noted. The primary infective source or the mode of infection could not be determined in this outbreak, but measles virus may have been transmitted to the monkeys from human visitors while the monkeys were on exhibit.

Animals↗
PubMed1999

The comparison of histologic gastritis in patients with duodenal ulcer, chronic gastritis, gastric ulcer and gastric cancer.

This study was designed to investigate the differences of histologic gastritis according to the endoscopic diagnosis, and between H. pylori positive and negative gastritis, using the Sydney system. A total of 122 patients (42 duodenal ulcer, 31 chronic gastritis, 35 gastric ulcer and 14 gastric cancer) underwent endoscopy with biopsies from the antrum and body. Among the 122 patients, 104 (85%) were H. pylori positive. H. pylori density of the antrum was significantly higher in duodenal ulcer than in chronic gastritis, gastric ulcer, and gastric cancer. The positivity of intestinal metaplasia was lowest in duodenal ulcer and highest in gastric cancer. H. pylori density as well as grade of activity, inflammation and atrophy were significantly higher in the antrum than in the body in duodenal ulcer, while in chronic gastritis, gastric ulcer and gastric cancer there was no difference of H. pylori density, activity, inflammation and atrophy between the antrum and body. The grade of activity and chronic inflammation were significantly higher in H. pylori positive patients than in H. pylori negative patients in both the antrum and body. In conclusion, the gastritis of duodenal ulcer was mainly localized to the antrum, while the gastritis of chronic gastritis, gastric ulcer or gastric cancer was rather uniform in the antrum and body. H. pylori seemed to be related to the development of chronic inflammation and activity.

Adult↗
PubMed1999

Protective effect of chlormethiazole, a sedative, against acetaminophen-induced liver injury in mice.

OBJECTIVES: The hepatotoxicity of acetaminophen is not a result of the parent compound but is mediated by its reactive metabolite N-acetyl-p-benzoquinone imine. Cytochrome P4502E1 (CYP2E1) is the principal enzyme of this biotransformation, which accounts for approximately 52% of the bioactivation in human microsomes. Recently, chlormethiazole a sedative drug, is reported to be an efficient inhibitor of CYP2E1 activity in human beings. In this study we wished to evaluate whether chlormethiazole, an inhibitor of CYP2E1, could prevent acetaminophen-induced liver injury in mice. METHODS: Acetaminophen, at doses ranging from 200 to 600 mg/kg, was injected into the peritoneum of female C57BL/6 inbred mice fasted for four hours. Chlormethiazole (60 mg/kg) or 5% dextrose water was given 30 min before or 2 h after acetaminophen. Serum aminotransferase activities, histologic index score, survival rate and hepatic malondialdehyde levels were compared. RESULTS: Pretreatment with chlormethiazole 30 min before 400 mg/kg of acetaminophen completely inhibited acetaminophen-induced liver injury (median 118.5 U/L, range 75 to 142 vs. 14,070 U/L, range 5980 to 27,680 for AST; 49 U/L, range 41 to 64 vs. 15,330 U/L, range 13,920 to 15,940 for ALT). In mice receiving chlormethiazole 2 h after acetaminophen, the mean AST and ALT levels were also less elevated, reaching only 20% of the value of acetaminophen-only group. These protective effects were confirmed histologically. Whereas more than 50% of mice died at 500 mg/kg of acetaminophen, all the mice pretreated with chlormethiazole survived at the same dose. CONCLUSION: Chlormethiazole effectively reduces acetaminophen-induced liver injury in mice. Further studies are needed to assess its role in humans.

Acetaminophen↗
PubMed1999

Tolterodine for overactive bladder: time to onset of action, preferred dosage, and 9-month follow-up.

This is a prospective study of 28 patients who had urinary frequency (>8 times/day) and either urgency or urge incontinence (>1 time/day). After a 2-week run-in period (visit 1), the patients were started on tolterodine 1 mg twice a day (bid) (visit 2). They were followed at 4 and 8 weeks (visits 3 and 4). The patients were contacted by telephone 1 week after visit 2. Tolterodine was increased to 2 mg bid if the patient had incomplete improvement at either the initial phone call or during visit 3. Evaluation criteria were daily micturition charts including urinary frequency, nocturia, leakage episodes, average urine volume per day, and average voided volume. Tolterodine was well tolerated without side effects in 20 (80%) of 28 patients. Eight patients (20%) dropped out after enrollment because of side effects in 3, no improvement in 2, and missing visits (>1) in 3. Drug dosage in the 20 patients who tolerated tolterodine was 1 mg bid in 3 and 2 mg bid in 17 (85%). According to micturition charts, urinary frequency, nocturia, and leakage episodes decreased significantly after tolterodine treatment, whereas average urine volume per day and average voided volume did not change significantly. There were no electrocardiographic or biochemical abnormalities due to tolterodine treatment. Mean follow-up was 9.4 months. All 20 patients who tolerated tolterodine continue to take the medication without significant side effects. We conclude that tolterodine is well tolerated and effective for overactive bladders. Two milligrams bid is the dosage preferred by the majority of patients and the onset of action is seen within 1 week of treatment. Long-term compliance and efficacy are excellent, with no dropout in >9 months of follow-up.

Adult↗
PubMed1999

Concurrent multicentric hemangiosarcoma and ovarian teratoma in an aged Père david's deer (Elaphurus davidianus).

A 20-yr-old female Père David's deer (Elaphurus davidianus) died following a 3-wk history of depression, anorexia, and progressive respiratory distress. At necropsy, numerous soft to firm, tan or blood-filled nodular structures, 1-6 cm in diameter, were noted in the lung and the visceral and parietal pleura and within the mediastinum. Similar nodules were also found in the liver, spleen, kidney, and lymph nodes. Histologically, the nodules were diagnosed as hemangiosarcoma. A benign teratoma was present in the left ovary.

Animals↗
PubMed1999

Medical and minimally invasive treatment of urinary incontinence.

Newer agents and procedures give urologists more options in treating patients who have urinary incontinence related to such etiologies as an ineffective sphincter, detrusor hypersensitivity, obstruction, or a combination of these. Abolition of the involuntary contractions characteristic of detrusor instability can be accomplished pharmacologically or surgically. First-line anticholinergic agents are tolterodine and oxybutynin XL, given orally. Alternatively, intravesical administration provides a high concentration of drug, such as capsaicin or resiniferatoxin, at the detrusor muscle level. However, this commits the patient to intermittent self-catheterization. Surgery is reserved for those who have failed prolonged trials of conservative therapies. For patients with intractable urge incontinence, urologists have the new technique of sacral nerve stimulation.

Journal Article↗
PubMed1998

Transfer of second messengers through gap junction connexin 43 channels reconstituted in liposomes.

Gap junction channels reconstituted in liposomes provide a pathway for the transfer of second messengers. Gap junction channels were formed in the artificial unilamellar liposomes using immunoaffinity-purified connexin 43 gap junction protein from rat brain. Sucrose-permeable and -impermeable liposomes were separated on the basis of sucrose permeability in the iso-osmolar sucrose density gradient. The liposomes permeable to sucrose were also permeable to a communicating dye molecule, Lucifer yellow. In the present study, we examined the transfer of second messengers through the connexin 43 channels reconstituted in liposomes and first report the direct evidence that the gap junction channels are permeable to second messengers including adenosine 3',5'-cyclic phosphate and inositol 1,4,5-trisphosphate.

Animals↗
PubMed1998

High-level production of human growth hormone in Escherichia coli by a simple recombinant process.

Procedures have been devised for producing in Escherichia coli high yields of purified recombinant human growth hormone (hGH), by utilizing N-terminal pentapeptide sequence of human tumor necrosis factor-alpha, histidine tag and enterokinase cleavage site as a fusion partner. The fusion protein was produced as a soluble protein at the beginning of gene expression, but progressively became insoluble in Escherichia coli cytoplasm. The insoluble protein was solubilized by simple alkaline pH shift and purified to near homogeneity by Ni(2+)-chelated affinity chromatography. Following specific enterokinase cleavage, the recombinant hGH was purified by one-step anion exchange chromatography. The ease and speed of this recombinant process, as well as the high productivity, makes it adaptable to the large-scale production of hGH. Moreover, the highly efficient fusion partner could be applied to the production of other therapeutically important proteins.

Amino Acid Sequence↗
PubMed1998

Effect of customized small bowel displacement system in pelvic irradiation.

PURPOSE: Authors designed a customized small bowel displacement system (SBDS) to displace the small bowel out of the pelvic radiation fields and to minimize treatment related bowel morbidity. METHODS AND MATERIALS: From August 1995 to May 1996, 55 consecutive patients who received pelvic radiation therapy with the SBDS were included in this study. The SBDS consists of a customized Styrofoam compression device that can displace the small bowel out of the radiation fields and an individualized immobilization abdominal board for easy daily setup of the patient in prone position. After opacifying the small bowel with barium, the patients were laid prone and posterior-anterior (PA) and lateral (LAT) simulation films were taken with and without the SBDS. The volume of the small bowel included in the radiation fields with and without the SBDS were compared. RESULTS: Using the SBDS, the mean small bowel volume was reduced by 59% on PA and 51% on LAT films (p = 0.0001). In six patients (6 of 55, 11%), it was possible that no small bowel was included within the treatment fields. The mean upward displacement of the most caudal small bowel was 4.8 cm using the SBDS. Patients treated with the SBDS manifested a significantly lower incidence of diarrhea requiring medication (8 of 55, 15%) vs. those without the SBDS (24 of 39, 62%) (p < 0.05). CONCLUSION: The SBDS is a novel method that can be used to displace the small bowel away from the treatment portal effectively and to reduce the radiation therapy morbidity. Compliance with setup is excellent.

Adult↗
PubMed1998

Human insulin production from a novel mini-proinsulin which has high receptor-binding activity.

To increase the folding efficiency of the insulin precursor and the production yield of insulin, we have designed a mini-proinsulin (M2PI) having the central C-peptide region replaced with a sequence forming a reverse turn. The mini-proinsulin was fused at the N-terminus to a 21-residue fusion partner containing a His10 tag for affinity purification. The gene for the fusion protein was inserted downstream of the T7 promoter of the expression plasmid pET-3a, and the fusion proteins were produced as inclusion bodies in the Escherichia coli cytoplasm at levels up to 25% of the total cell protein. The protein was sulphonated, cleaved by CNBr and the M2PI mini-proinsulin was purified using ion-exchange chromatography. The refolding yield of M2PI was 20-40% better than that of proinsulin studied at the same molar concentrations, indicating that the short turn-forming sequence is more effective in the refolding process than the much longer C-peptide. Native human insulin was successfully generated by subsequent enzymic conversion of mini-proinsulin. The mini-proinsulin exhibited high receptor-binding activity, about 50% as potent as insulin, suggesting that this single-chained mini-proinsulin may provide a foundation in understanding the receptor-bound structure of insulin as well as the role of C-peptide in the folding and activity of proinsulin.

Amino Acid Sequence↗
PubMed1998

Growth-associated synthesis of recombinant human glucagon and human growth hormone in high-cell-density cultures of Escherichia coli.

Synthesis of two recombinant proteins (human glucagon and human growth hormone) was investigated in fed-batch cultures at high cell concentrations of recombinant Escherichia coli. The glucose-limited growth was achieved without accumulation of metabolic by-products and hence the cellular environment is presumed invariable during growth and recombinant protein synthesis. Via exponential feeding in the two-phase fed-batch operation, the specific cell growth rate was successfully controlled at the desired rates and the fed-batch mode employed is considered appropriate for examining the correlation between the specific growth rate and the efficiency of recombinant product formation in the recombinant E. coli strains. The two recombinant proteins were expressed as fusion proteins and the concentration in the culture broth was increased to 15 g fusion growth hormone 1(-1) and 7 g fusion glucagon 1(-1). The fusion growth hormone was initially expressed as soluble protein but seemed to be gradually aggregated into inclusion bodies as the expression level increased, whereas the synthesized fusion glucagon existed as a cytoplasmic soluble protein during the whole induction period. The stressful conditions of cultivation employed (i.e., high-cell-density cultivation at low growth rate) may induce the increased production of various host-derived chaperones and thereby enhance the folding efficiency of synthesized heterologous proteins. The synthesis of the recombinant fusion proteins was strongly growth-dependent and more efficient at a higher specific growth rate. The mechanism linking specific growth rate with recombinant protein productivity is likely to be related to the change in cellular ribosomal content.

Colony Count, Microbial↗
PubMed1998

Very high frequency ultrasound analysis of a new phakic posterior chamber intraocular lens in situ.

PURPOSE: To use very high frequency ultrasound scanning for in situ analysis of a new phakic posterior chamber intraocular lens (No-Touch; International Visions Inc, Cincinnati, Ohio). METHODS: In this pilot study, very high frequency ultrasound (50 MHz) wide-angle (15 mm) full anterior segment scans were obtained in two patients who had undergone phakic posterior chamber intraocular lens implantation into legally blind eyes with normal anterior segment anatomy. RESULTS: Very high frequency ultrasound B-scan images delineated the phakic posterior chamber intraocular lens within the posterior chamber. The relations to the sulci were clearly imaged. Anatomic relations of the phakic posterior chamber intraocular lens optic and haptics were visualized in both static (light/dark) and kinetic (distance/accommodative) states. CONCLUSION: Very high frequency ultrasound wide-angle scanning provides a unique tool to noninvasively evaluate the eye preoperatively and the static and kinetic relations of this new refractive device within the posterior chamber.

Adult↗
PubMed1998

In vivo differential diagnosis of prostate cancer and benign prostatic hyperplasia: localized proton magnetic resonance spectroscopy using external-body surface coil.

Localized proton-stimulated echo acquisition mode (STEAM) spectroscopy was performed in seven patients with benign prostatic hyperplasia (BPH), six patients with prostate cancer, and seven healthy volunteers to determine whether citrate levels detected using a saddle-type external-body surface coil (two loops of 13 cm x 17 cm) could reliably discriminate BPH from prostatic cancer. Relative area ratios of citrate level to choline plus creatine or citrate to lipid signal were compared with postoperative pathologic histology findings. The metabolic signals were well detectable as much as the line width of water resonance was ranging from 5 to 9 hz. Average SNRs of citrate in BPH and prostate cancer were 11.4 and 1.9, respectively. The major finding was consistently lower citrate levels in prostate cancer compared with BPH and normal prostate central gland. This was significantly (p < 0.01) reflected by lower mean citrate/[creatine+choline] peak area ratio and citrate/lipid peak area ratio observed for region of cancer (0.446 +/- 0.063, 0.097 +/- 0.030) compared with BPH (1.458 +/- 0.107, 0.786 +/- 0.162) and normal central gland (1.418 +/- 0.129, 0.175 +/- 0.011), respectively. These studies demonstrate the potential of citrate spectrum detected by an external-body surface coil as an in vivo marker for discriminating prostate cancer from BPH.

Adult↗