• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.317-325
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• 2001

For heuristic purposes, the relative ratio of urease contents inside and outside cells was surveyed using nine ureB+ strains of Helicobacter pylori. the ratio of the enzyme specific activity appeared to vary greatly between the various H. pylori strains, ranging from 0.5 to 2.5. Besides the above compartment, urease was also richly found in the membrane fraction, especially in either peripheral or integral form. The urease distribution across the H. pylori membrane was significantly influenced by the ambient pH; the specific activity of external urease was highest at pH 5.5 with a narrow plateau, whereas the internal specific activity was highest within a pH range of 4.5 to 6.5 with a broad plateau. These finding strongly suggest that H. pylori urease is secretory and responded to the external pH. However, at pH 4.0 or below, no urease activity was detected in either the internal or external compartment, although an increase in the color development with 2,4,6-trinitrobenzene sulfonate (TNBS) was observed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that these phenomena may be related to a specific proteolysis in certain proteins, including urease or ${\gamma}$-glutamyl transpeptidase. Interestingly, the effect of ammonium ions n alleviating the enzyme inactivation inside the H. pylori cells was remarkably similar to that of D-glucose. In addition, it would appear that the cation acted as a surrogate of not only $Na^+$ but also $K^+$ thereby increasing the H. pylori P-type ATPase activity. This is of great interest, as it implies that the urease action in H. pylori is indispensible at any locus.

• Journal of Medicine and Life Science
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• 제15권2호
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• pp.108-111
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• 2018

Extra-corporeal membrane oxygenation (ECMO) has the potential to rescue patients in cardiac arrest or respiratory failure. ECMO has two systems such as veno-arterial and veno-venous circulation. In cardiac arrest resulting from acute myocardial infarction, veno-arterial ECMO is mandatory for systemic circulation and oxygenation. A 75-year old female patient underwent primary coronary intervention for acute myocardial infarction. Despite successful revascularization, recurrent ventricular tachycardia and heart failure were progressing. We performed a veno-arterial ECMO through the femoral artery and vein, then the patient seemed to be stable clinically. However, laboratory studies, echocardiography, and vital signs indicated multi-organ failure and decreasing cardiac function. We found out an error that we performed veno-venous ECMO instead of veno-arterial ECMO. We added a femoral artery cannula and exchange the circuit system to veno-arterial ECMO. While the systemic circulation seemed to be recovered, the left ventricular function was decreased persistently. A hypovolemia resulting from pulmonary hemorrhage was occurred, which lead to ECMO failure. The patient died of cardiac arrest and multi-organ failure 23 hours after ECMO. Because the color of arterial and venous circuits represent the position and efficacy of ECMO, if unexpected or abnormal circuit colors are detected, prompt and aggressive evaluation for ECMO function is mandatory.

• 상하수도학회지
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• 제35권3호
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• pp.197-204
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• 2021

In MBR, extracellular polymeric substance (EPS) is known as an important factor of fouling; soluble EPS (sEPS) affects internal contamination of membrane, and bound EPS (bEPS) affects the formation of the cake layer. The production of EPS changes according to the composition of influent, which affects fouling characteristics. Therefore, in this study, the effects of the F/M ratio on the sEPS concentration, bEPS content, and fouling were evaluated. The effects of F/M ratio on the amount and composition of EPS were confirmed by setting conditions that were very low or higher than the general F/M ratio of MBR, and the fouling occurrence characteristics were evaluated by filtration resistance distribution. As a result, it was found that the sEPS increased significantly with the increase of the F/M ratio. When the substrate was depleted, bEPS content decreased because bEPS was hydrolyzed into BAP and seemed to be used as a substrate. In contrast, when the substrate is sufficient, UAP (utilization-associated products) was rapidly generated in proportion with the consumption of the substrate. UAP has a relatively higher Protein/Carbohydrate ratio (P/C ratio) than BAP, and this means, it has a higher adhesive force to the membrane surface. As a result, UAP seems like causing fouling rather than BAP (biomass-associated products). Therefore, R_f (Resistance of internal contamination) increased rapidly with the increase of UAP, and R_c (Resistance of cake layer) increased with the accumulation of bEPS in proportion, and as a result, the fouling interval was shortened. According to this study, a high F/M ratio leads to an increment in UAP generation and accumulation of bEPS, and by these UAP and bEPS, membrane fouling is promoted.

• Membrane and Water Treatment
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• 제4권4호
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• pp.251-263
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• 2013

The internal reflux effect on dialysis through the retentate phase of a countercurrently cross-flow rectangular module is investigated. Theoretical analysis of mass transfer in cross-flow devices with or without recycling is analogous to heat transfer in cross-flow heat exchangers. In contrast to a device without reflux, considerable mass transfer is achievable if cross-flow dialyzers are operated with reflux, which provides an increase in fluid velocity, resulting in a reduction in mass-transfer resistance. It is concluded that reflux can enhance mass transfer, especially for large flow rate and feed-concentration operated under high reflux ratio.

• 대한두경부종양학회지
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• 제11권1호
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• pp.24-29
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• 1995

Melanoma of the mucous membrane is a rare condition and has the worse prognosis than that of any other sites. It is usually asymptomatic in early stage and difficult to find out the primary lesion by visual examination, and these facts lead to delay in diagnosis and reduce the curability. The major factor of failure in treatment of melanoma is local recurrence rather than regional spread. Because the radical procedure is difficult in head and neck lesion due to anatomical limitation, radiation therapy and chemotherapy can be used in the treatment of local recurrence. We experienced two cases of nasopharyngeal melanoma in advanced stage and treated them with radiation therapy and/or chemotherapy. And both patients showed relatively favorable response to these palliative treatments.

• 대한약리학회지
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• 제18권2호
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• pp.89-102
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• 1982

The $Na^+-and\;K^+-induced\;Ca^{++}$ release was measured isotopically by millipore filter technique in pig heart mitochondria. With EGTA-quenching technique, the characteristics of mitochondrial $Ca^{++}-pool$ and the sources of $Ca^{++}$ released from mitochondria by $Na^+\;or\;K^+$ were analyzed. The mitochondrial $Ca^{++}-pool$ could be distinctly divided into two components: internal and external ones which were represented either by uptake through inner membrane, or by energy independent passive binding to external surface of mitochondria, respectively. In energized mitochondria, a large portion of $Ca^{++}$was transported into internal pool with little external binding, while in de-enerigzed state, a large portion of transported $Ca^{++}$ existed in the external pool with limited amount of $Ca^{++}$ in the internal pool which was possibly transported through the $Ca^{++}-carrier$ present in the inner membrane. $Na^+$ induced the $Ca^{++}$ release from both internal pool and external pool and external binding pool of mitochondria. In contrast, $K^+$ did not affect $Ca^{++}$ of the internal pool, but, displaced $Ca^{++}$ bound to external surface of the mitochondria. When the $Ca^{++}-reuptake$ was blocked by EGTA, the $Ca^{++}$ release from the internal pool by $Na^+$ was rapid; the rate of $Ca^{++}-efflux$ appeared to be a function of $[Na^+]^2$ and about 8mM $Na^+$ was required to elicit half-maximal velocity of $Ca^{++}-efflux$. So it was revealed that $Ca^{++}-efflux$ velocity was particulary sensitive to small changes of the $Na^+$ concentration in physiological range. Energy independent $Ca^{++}-binding$ sites of mitochondrial external surface showed unique characteristics. The total number of external $Ca^{++}-binding$ sites of pig heart mitochondria was 29 nmoles per mg protein and the dissociation constant(Kd) was $34{\mu}M$. The $Ca^{++}-binding$ to the external sites seemed to be competitively inhibited by $Na^+\;and\;K^+$; the inhibition constant(Ki) were 9.7 mM and 7.1 mM respectively. Considering the intracellular ion concentrations and large proportion of $Ca^{++}$ uptake in energized mitochondria, the external $Ca^{++}-binding$ pool of the mitochondria did not seem to play a significant role on the regulation of intracellular free $Ca^{++}$ concentration. From this experiment, it was suggested that a small change of intracellular free $Na^+$ concentration might play a role on regulation of free $Ca^{++}$ concentration in cardiac cell by influencing $Ca^{++}-efflux$ from the internal pool of mitochondria.

• 한국물환경학회지
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• 제21권6호
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• pp.602-608
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• 2005

A laboratory-scale experiment was conducted to investigate control of soluble microbial products (SMP) by the internal recycle rate in the submerged membrane separation activated sludge process. The internal recycle rate of the reactor RUN 1 and RUN 2 were 100 % and 200 %, respectively. SMP concentration was rapidly accumulated in the reactor (RUN 1). The variation of accumulated SMP concentration was related to the denitrification rate at the beginning experiment however SMP concentration decreased without correlatively to the denitrification rate during long operation time. The microbial kinetic model was rapidly presented in the both microbial growth and extinction in the reactor (RUN 1). In the SMP kinetic model, Internal recycle rate is the lower, value of UAP and BAP which SMP matter were presented low. The study about development of kinetic model is relatively well adjusted to the experiment exception SMP. In the future, SMP formation equation must be thought that continually research is necessary.

• Journal of Microbiology
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• 제42권4호
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• pp.328-335
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• 2004

The human immunodeficiency virus type 1 (HIV-I) Tat protein transduction domain (PTD), which con­tains rich arginine and lysine residues, is responsible for the highly efficient transduction of protein through the plasma membrane. In addition, it can be secreted from infected cells and has the ability to enter neighboring cells. When the PTD of Tat is fused to proteins and exogenously added to cells, the fusion protein can cross plasma membranes. Recent reports indicate that the endogenously expressed Tat fusion protein can demonstrate biodistribution of several proteins. However, intercellular transport and protein transduction have not been observed in some studies. Therefore, this study exam­ined the intercellular transport and protein transduction of the Tat protein. The results showed no evi­dence of intercellular transport (biodistribution) in a cell culture. Instead, the Tat fusion peptides were found to have a significant effect on the transduction and intercellular localization properties. This sug­gests that the HIV-1 PTD passes through the plasma membrane in one direction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권2호
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• pp.85-89
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• 2012

Objectives: This study was to evaluate the effect of vertical bone gain and success rate and analyze the failure cases using the hydrodynamic piezoelectric internal sinus elevation (HPISE) technique. Materials and Methods: Patients who had been operated in the three centers including Daegu Catholic University Medical Center were selected for this study. The mucoperiosteal flap was elevated, and the sinus floor was then broken by specially designed piezoelectric insert, with hydraulic pressure applied to the sinus membrane for even elevation. Afterward, implants were placed. Panoramic radiogram or computed tomogram was taken before and after surgery and at the second operation and prosthesis placement. Later, changes in vertical height were measured and compared. The survival rate was based on the criteria of Buser et al. and Cochran et al. Results: In this study, 8 implants failed out of a total of 169 implants, resulting a success rate of 95.3%. These failure cases were due to insufficient initial stability or sinus membrane perforation. The mean of radiographic vertical height change at prosthesis placement was 5.7 mm (0.5-10.5 mm). Conclusion: In this study, HPISE technique was found to be a predictable treatment for atrophic maxilla and an alternative technique to the lateral approach.

• Tuberculosis and Respiratory Diseases
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• 제69권2호
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• pp.75-80
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• 2010

The year of 2009~2010 brought a number of concepts and new ideas were evaluated with promising results. However, some studies that challenged many beliefs. In acute respiratory distress syndrome (ARDS), recent clinical studies took into consideration of pathophysiologic changes of respiratory system compliance. Meta-analysis of positive end-expiratory pressure trials showed survival benefit of high positive end-expiratory pressure in ARDS. Until now, prone positioning did not show survival benefit in patients with ARDS. Extracorporeal membrane oxygenation (ECMO) based management improved survival in patients with severe ARDS. ECMO can be a management option in severe ARDS. Sedation is a standard practice in critically ill patients needing mechanical ventilation. However, Danish group reported less sedation of critically ill patients receiving mechanical ventilation was associated with an increase in days without ventilation. Although this single center study has some limitations, the overall results are promising. Use of maximal sterile barrier precautions (mask, sterile gown, sterile gloves, and large sterile drapes) with chlorhexidine-impregnated dressing reduced central venous catheter related infection. Selective oropharyngeal decontamination (application of topical antibiotics in the oropharynx) reduced the mortality rate of an intensive care unit (ICU) population. Normoglycemia in Intensive Care Evaluation and Survival Using Glucose Algorithm Regulation (NICE-SUGAR) trial reported intensive glucose control increased mortality among adults in the ICU. Some of the results of above papers are promising. However, some ideas may need for more frequent individual assessment and increase the workload of ICU staffs. Before implementation of new practice in ICU, we should take into consideration of individual hospital situation including human and material resources.