Biomedical subjects

I S Chung

Publications and source records attributed to I S Chung.

26 records · Page 2Linked to original sources

PubMed1999

Clinical validation of the Helikit: a 13C urea breath test used for the diagnosis of Helicobacter pylori infection.

OBJECTIVE: To assess the clinical performance of the Helikit, a 13C urea breath test, in the diagnosis of Helicobacter pylori infection. METHODS: A total of 205 participants were assessed in Canada and Korea for H. pylori infection status by endoscopy, or a combination of IgG ELISA and CLO test, as well as by the Helikit. The Helikit contains 75 mg of 13C urea as well as citric acid, flavor enhancers and stabilizers in a single plastic cup. The powder is dissolved in 75 mL of water for oral administration. No extra mixing or dilution steps are required. RESULTS: Using the biopsy-derived data as the gold standard the Helikit displayed a clinical sensitivity of 93.5% (95% confidence interval 88.5 to 98.5%) and a clinical specificity of 97.3% (94.3 to 100%). An overall diagnostic efficiency of 95.6% (92.8 to 98.4%) was obtained. No statistically significant difference in the performance characteristics was found between Korea and Canada. No significant adverse events were noted. CONCLUSIONS: The Helikit offers an easy, safe and accurate approach to the diagnosis of H. pylori infection.

Adult↗

PubMed1999

Management of foreign bodies in the gastrointestinal tract: an analysis of 104 cases in children.

BACKGROUND AND STUDY AIMS: Ingested foreign bodies may be managed by endoscopy, observation, or surgery. The aim of the study was to investigate the methods of removal of foreign bodies according to type and location, success rates, and complications. PATIENTS AND METHODS: The charts of 104 children who had ingested foreign bodies were retrospectively reviewed. RESULTS: Of the patients, 80 (76.9%) were managed endoscopically. The overall success rate for endoscopic management was 98.8%. There were no complications during endoscopic interventions. In 23 cases the foreign bodies spontaneously passed through the gastrointestinal tract (22.1%). Surgical removal of a foreign body was done in only one case (0.96%). The majority of the foreign bodies which were located in the upper gastrointestinal tract could be removed endoscopically regardless of the nature of the material. Foreign bodies in the small and large intestine tended to pass through spontaneously without complications. CONCLUSIONS: It appears that the endoscopic approach is the preferable method for the extraction of upper gastrointestinal foreign bodies in child patients because of its high success rate, and that foreign bodies in the small and large intestine tend to be passed spontaneously without complications.

Adolescent↗

PubMed1994

[Effects on hemolysis of the manually operated portable cardiopulmonary bypass system].

We studied the effects on hemolysis of our manually operated, portable cardiopulmonary bypass system with two self-inflatable reservoir-pumps in parallel by using bovine blood. The blood shed from both the jugular vein and the carotid artery, immediately after slaughter, was divided into three plastic containers, one for the control, one for manual circulation, and the other for conventional circulation with a roller-pump. Small bore catheters were intentionally placed into the inflow and outflow routes of both circulation systems to simulate clinical situations. Free hemoglobin and potassium in plasma were measured every 30 min during the experimental circulation for 120 min. The free hemoglobin in plasma increased gradually under manual circulation, but this increase was statistically insignificant when compared with the variances of those in the conventional circulation and the control blood groups. The values of the potassium in the plasma showed no differences among the three blood groups. Our manually operated, portable cardiopulmonary bypass system will be a valuable adjunct for emergency medicine.

Animals↗

PubMed1988

Degenerative changes after meniscectomy and meniscal regeneration.

In an experimental study on rabbit knees, regeneration of the medial meniscus occurred following 9 out of 10 meniscectomies, compared with only 1 out of 10 lateral menisci. Degenerative changes in the articular cartilage were seen in 8 of 9 knees where the lateral cartilage failed to regenerate, but in only 2 of 9 with a regenerated medial cartilage. The rate of regeneration is lower after lateral meniscectomy and this may partially explain the occurrence of more severe degenerative changes after this operation.

Animals↗

PubMedDate not supplied

Production of human alkaline phosphatase, a secreted, glycosylated protein, from a baculovirus expression system and the attachment-dependent cell line Trichoplusia ni BTI-Tn 5B1-4 using a split-flow, air-lift bioreactor.

A split-flow, air-lift bioreactor for the cultivation of insect cells to produce recombinant protein is described. It can be used advantageously with attached cell systems. This bioreactor incorporates two sections: a rise and a downcomer. Trichoplusia ni BTI-Tn 5B1-4 cells are grown on a support material of glass beads or microcarriers placed in the downcomer. This cell line is more productive than other commonly used insect cell lines, but it has the disadvantage of being difficult to use at large volumes since it is not easily adaptable to suspension culture. Adequate oxygen demand is supplied by sparging without direct exposure of cells to air bubbles. Nutrients are supplied convectively to the attached cells on support material as the fluid flows through the downcomer. The split-flow, air-lift bioreactor appears to be suitable for insect cell culture and is potentially scalable. It can provide a high surface-to-volume ratio and can be operated in batch or continuous mode. A lab-scale prototype bioreactor has been constructed and tested for the production of a secreted, glycosylated recombinant protein (human alkaline phosphatase) or seAP using an Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) vector. With a ratio of riser cross-sectional area to downcomer cross-sectional area of 1, an aspect ratio of 4.4, an air-flow rate of 54 mL/min in the riser, and a bed of 2400 3-min nonporous glass beads, 10.7 micrograms/mL of seAP was produced using an MOI (multiplicity of infection or the ratio of plaque-forming units to cells) of 10.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗

PubMedDate not supplied

Effects of epidural injection on spinal block during combined spinal and epidural anesthesia for cesarean delivery.

BACKGROUND AND OBJECTIVES: Epidural injection has been known to enhance spinal anesthesia in combined spinal and epidural (CSE) anesthesia. Saline and local anesthetics have been reported to have a volume effect, elevating sensory level when supplementing a volume into the epidural space. We evaluated the effects of epidural injection when using the CSE technique for cesarean delivery. METHODS: Sixty-six parturients were allocated randomly into group C (control, n = 21), S (saline, n = 21), or B (bupivacaine, n = 24): epidural injections of 10 mL saline and 0.25% bupivacaine were given in groups S and B, respectively, 10 minutes after they received 8 mg of 0.5% hyperbaric bupivacaine intrathecally, and no injection was given in group C. The sensory level at 10 minutes, the maximal level and the time to reach it, and degree of motor block and muscle relaxation were compared. We also investigated intraoperative side effects and postoperative findings in the postanesthesia care unit. RESULTS: Epidural injection raised the sensory level significantly in groups S and B, but the maximal height of sensory block and degree of muscle relaxation did not differ among the groups. Fewer patients complained of intraoperative pain in group B than in the other groups (P <.001). CONCLUSIONS: We could not achieve satisfactory surgical analgesia with 8 mg of hyperbaric bupivacaine injected into the subarachnoid space using the needle-through-needle technique in cesarean deliveries. An epidural saline injection elevated the sensory level, which did not improve the spinal block, whereas an epidural injection of 10 mL of 0.25% bupivacaine enhanced the spinal block and sustained the block postoperatively.

Adult↗

PubMedDate not supplied

Successful treatment of massive lower gastrointestinal bleeding caused by mixed infection of cytomegalovirus and mucormycosis in a renal transplant recipient.

We describe a case of lower gastrointestinal bleeding due to mixed infection of cytomegalovirus (CMV) and mucormycosis in a renal transplant recipient. A 33-year-old male received renal transplantation and his clinical course was uneventful. On the 18th postoperative day, acute rejection was developed and this was treated with high-dose methylprednisolone and OKT3. During antirejection treatment, sudden onset massive hematochezia was developed. Emergency colonofibroscopy revealed multiple colonic ulcers and pathologic findings were consistent with mucormycosis and CMV infection. The patient was successfully treated with amphotericin B (1.0-1.5 mg/kg) and ganciclovir (62.5-125 mg/day) for 5 weeks. To our knowledge, this is the first report showing coexistence of mucormycosis and CMV in the colon ulcer base. This finding suggests that CMV infection may trigger fungal infection in the pathogenesis of colonic ulcer.

Adult↗

PubMedDate not supplied

Activation of multiple effector pathways of immune system by the antineoplastic immunostimulator acidic polysaccharide ginsan isolated from Panax ginseng.

In the present study an acidic polysaccharide ginsan, with a molecular weight of 150,000, devoid of lectin properties, was purified from Panax ginseng C.A. Meyer (Araliaceae). Ginsan induced the proliferation of T cells and B cells. Spleen cells became cytotoxic to a wide range of tumor cells without major histocompatibility complex-restriction after 4 or 5 days culture in vitro with ginsan. For the generation of these ginsan-activated killer (AK) cells adherent macrophages and CD4+ cells were needed as accessory cells. The generation of ginsan-AK cells was blocked in the presence of anti-IL-2, anti-IFN gamma, anti-IL-1 or anti-TNF alpha antibodies, showing the importance of these cytokines in the process. The surface phenotypes of the 4 day-cultured ginsan-AK cells was Thy1+, AsGM1+, CD8+, which is distinct from rIL-2 induced lymphokine activated killer (LAK) cells that were CD8. The ginsan also activated macrophages to produce reactive nitrogen intermediates and become tumoricidal. It also exhibited significant in vivo antitumor activity against B16 melanoma cells lines, and in the benzo(a)pyrene-induced autochthonous lung tumor model, at much lower doses than the maximum tolerate doses. Indeed, no mice died, which injected with ginsan at 1g/kg body weight intraperitoneally. In conclusion, 'ginsan' could potentially be an ideal nontoxic antineoplastic immunostimulator by activating multiple effector arms of the immune system.

Adjuvants, Immunologic↗