• Tuberculosis and Respiratory Diseases
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• v.50 no.4
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• pp.462-472
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• 2001

Background : The determinants of intubation and the response to therapy in COPD patients with hypercapnic respiratory failure were retrospectively reviewed. Methods : This study involved a review of 132 episodes of hypercapnic respiratory failure($PaCO_2\;{\geq}\;50\;mmHg$ and $pH\;{\leq}\;7.35$). The time frame for resolution or the time to intubation of patients who were admitted between 1996 and 1999 was analyzed. Results : Out of 132 hypercapnic episodes, 49(37%) required intubation. A comparison was made with the 83 cases that responded to treatment. Patients requiring intubation had a greater severity of illness, which included a higher APACHE II (Acute Physiology and Chronic Health Evaluation II) score ($20{\pm}5$ vs $14{\pm}4$ ; p<0.01), a higher WBC, a higher serum BUN, and greater acidosis (pH, $7.23{\pm}0.11$ vs $7.32{\pm}0.04$ ; p<0.01). Those with the most severe acidosis(pH<7.20) had the highest intubation rate(87%) and shortest time to intubation($2{\pm}3\;h$). Conversely, those with an initial pH 7.31 to 7.35 were less likely to be intubated(20%), and had a longer time to intubation($97{\pm}121\;h$). The patients with a pH 7.21 to 7.25($4.1{\pm}2.9$ day) required longer period of time to respond to medical treatment than patients with a pH of 7.31 to 7.35($2.2{\pm}3.1$ day). Of those patients requiring intubation, half(55%) were intubated within 8 h of admission, and most (75%) within 24 h. Of those patients responding to treatment medical therapy, half(52%) recovered within 24 h and most (78%) recovered within 48 h. Conclusion: Respiratory acidosis at the initial presentation is associated with an increased likelihood of intubation. This should assist in deciding help with the decision whether to treat patients medically, institute noninvasive ventilation, or proceed to intubation.

• Progress in Medical Physics
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• v.12 no.2
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• pp.113-124
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• 2001

For veterinary imaging diagnosis, we obtained MR images of the canine brain, spine, kidney and pelvis from 3T MRI system which was equipped with the world first 3T active shield magnet. Spin echo (SE) and fast Spin Echo (FSE) images were obtained from the canine brain, spine, kidney and pelvis of normal and sick dogs using a homemade birdcage and transverse electromagnetic (TEM) resonators operating in quadrature and tuned to 128 MHz. In addition, we employed a homemade saddle shaped RF coil. Typical common acquisition parameters were as follows: matrix=512$\times$512, field of view (FOV)=20cm, slice thickness=3 w, number of excitations (NEX)=1. For T1-weighted MR images, we used TR=500 ms, TE=10 or 17.4 ms. For T2-weighted MR images, we used TR=4000 ms, TE=108 ms. Signal to noise ratio (SNR) of 3T system was measured 2.7 times greater than that of prevalent 1.57 system. The high resolution images acquired in this study represent more than a 4-fold increase in in-plane resolution relative to conventional images obtained with a 20 cm field of view and a 5 mm slice thickness. MR images obtained from 3T system revealed numerous small venous structures throughout the image plane and provided reasonable delineation between gray and white matter The present results demonstrate that the MR images from 3T system could provide better diagnostic quality of resolution and sensitivity than those of 1.5T system. The elevated SNR observed in the 3T high field magnetic resonance imaging can be utilized to acquire images with a level of resolution approaching the microscopic structural level under in vivo conditions. These images represent a significant advance in our ability to examine small anatomical features with noninvasive imaging methods. Moreover, MRI technique could begin to apply for veterinary medicine in Korea.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.533-539
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• 2010

Stem cell-based therapy is under intensive investigation to treat acute renal failure (ARF). The purpose of this study was to evaluate available ARF models, and suggest a model appropriate to therapeutic evaluation of the stem cells in preclinical approach by determining the optimum concentration of nephrotoxic agents and duration of ischemia induction. Three different types of available acute kidney injury (AKI) animal models were analyzed using rats: Cisplatin (saline, 5 and 7.5 mg/kg, IP) or glycerol (saline, 8 and 10 ml/kg, IM)-induced nephrotoxicity as toxic models and ischemia-induced (sham, 35 and 45 minutes) nephropathy as an ischemic model. The relevance and applicability to investigate especially the regenerative ability of stem cells were evaluated regarding morphology, renal function and survival at this time point. In the point of renal function, 10 ml glycerol/kg and 7.5 mg cisplatin/kg model in toxic models and 45 min model in ischemia models showed significant decrease for the longer observation time compared to 8 ml glycerol/kg, 5 mg cisplatin/kg and the 35 min ischemia models, respectively. All groups were observed no mortality except 45 min-ischemia model with 50% survival. Histological significant alterations including cast formation in the tubular lumen, tubular necrosis and apoptosis were revealed on the second day in either ischemiaor glycerol-induced models, and on day 5 in cisplatin-induced models. The results indicate that ischemia 35 min-, cisplatin 7.5 mg/kg- and glycerol 10 ml/kg-induced AKI would be ideal animal models to monitor a outcome parameter related to the therapeutic effects on renal function with noninvasive techniques in the same animal at multiple time points. Our findings also suggest that the best time points for the functional or histological interpretation of renal will be on day 2 in both glycerol- and ischemia-induced AKI models and on day 5 in cisplatin-induced AKI.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.139-148
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• 1993

Both SCC 12 and SCC 13 cell lines were derived from squamous cell carcinoma (SCC) of the skin (Wu and Rheinwald, 1981). In the present study, we compared the inherent invasive activity in their raft cultures where most in vivo characteristics of epidermis can be reproduced by cell culture method. The raft culture of SCC 12 cell line produced many invading colonies within the collagen lattice and basal-like cells in the middle of differentiating cell layers, but no invasive activity was observed in the SCC 13 raft culture. We investigated which factors are implicated in inherent invasive activity of SCC 12 cell line by examining basal levels of type I collagenase, EGF receptor, fibronectin, and its receptor in two cell lines. Among them, only type I collagenase was significantly higher in invasive SCC 12 cells than in non-invasive SCC 13 cells. Furthermore, we tried to investigate mechanisms underlying between SCC 12 cell's inherent invasive activity and its high basal level of type I collagenase. As one of them, discrepancy in TGF alpha mediated responses between two cell lines was observed. In SCC 13 cells, TGF alpha initially stimulated type I collagenase at 12 h after TGF alpha treatment and then its down regulation was followed from 24 h even though TGF alpha was continuously present in the medium. However in SCC 12 cells, TGF alpha continuously stimulated type I collegenase up to 48 h. We propose that defect in EGF receptor's down-regulation may be involved in lack of type I collagenase's down-regulation and its possible connection to invasive activity of SCC 12 cell line.

• Tuberculosis and Respiratory Diseases
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• v.41 no.6
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• pp.616-623
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• 1994

Objectives: Careful evaluation about mediastinal involvement is important in the management of patients with non-small cell lung cancer. Invasive staging procedure such as mediastinoscopy is advocated because of the unreliability of noninvasive staging methods such as CT, MRI. We compared differences between pre- and postoperative staging in non-small cell lung cancer without lymphadenopathy on CT scan and investigated the methods for more accurate preoperative staging. Methods & Results: 1) Records of a total of 41 patients with preoperative $T_{1-3}N_0M_0$ non-small cell lung cancer were reviewed and the histologic types of tumors were squamous cell carcinoma in 32 cases, adenocarcinoma in 6 cases and large cell carcinoma in 3 cases. Twenty-four cases were central lesions and seventeen cases were peripheral lesions. 2) Among the 32 cases with preoperative $T_2$, 2 cases were identified postoperatively as $T_3$ with invasion of chest wall and among 6 cases with preoperative $T_3$, 1 case was identified postoperatively as $T_4$ with invasion of aorta and pulmonary arteries. 3) After the operation of 35 cases with $T_{1-2}$, 5 cases were $N_1$ and 3 cases were $N_2$ postoperatively. After the operation of 6 cases with $T_3$, 2 cases were $N_1$ and 3 cases were $N_2$ postoperatively. Preoperative $T_3$ showed more intrathoracic lymph node metastases and higher $N_2/N_1$ involvement ratio than preoperative $T_{1-2}$. 4) Complete surgical resections were done in 34 out of 41 cases. Incomplete resection were done in all postoperative $N_2$ tumors. Conclusion: Invasive staging procedures such as mediastinoscopy should be considered in the case of preoperative $T_3$ non-small cell lung cancer even though mediastinal lymphadenopathy is not recognized on the CT scan of the chest.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.99-106
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• 1998

Background: Bronchial asthma is a complex disease, which is characterized by spontaneous exacerbations of airway obstruction and persistent bronchial hyperresponsiveness. Animal models have fallen short of reproducing the human disease, particularly in mimicking the spontaneous and persistent airflow obstruction that characterized in asthma. In animals, airflow obstruction is usually assessed by measuring airflow resistance during tidal breathing under such invasive technique as tracheostomy and anesthesia. A noninvasive technique for measuring pulmonary function in small animals is needed to evaluate long-term changes in lung function during the course of experimentally produced disease without sacrificing the animal. Purpose: The purpose of this study was to evaluate early bronchoconstrcition after allergen challenge and airway responsiveness (AR) to inhaled methacholine in nonanethetized, unrestrained guinea pigs. Method: Guinea pig model of asthma was sensitized by subcutaneous injection with ovalbumin and challenged by inhalation of aerosolized ovalbumin(1% wt/vol ovlabumin). Airflow obstruction of conscious guinea pig was measured as specific airway resistance (airway resistance $\times$ thoracic gas volume). Airway resistance and thoracic gas volume of conscious guinea pig were assessed by body plethysmography before challenge and at regular intervals for as long as 30 minutes after challenge. AR to aerosolized methacholine of asthma group was compared with that of control group in body plethysmography. Result: Asthma model<> developed in 13 (65%) among 20 guinea pigs, in which early responses occurred in the airways after the exposure to inhalation with ovalbumin. Airway challenge with ovalbumin caused increase in specific airway resistance, which peaked at 6 minutes and amounted to a $231.5{\pm}30.4%$ increase from baseline. AR to aerosolized methacholine of asthma model increased significantly compared with control group. Conclusion: These results have showed a useful animal model to evaluate early bronchoconstrcition after allergen challenge and airway responsiveness in nonanethetized, unrestrained guinea pigs.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.583-591
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• 1997

The functional derangement of skeletal muscles which may be attributed to chronic hypoxia has been accepted as a possible mechanism of exercise impairment in patients with chronic obstructive pulmonary disease (COPD). The metabolic changes in skeletal muscle in patients with COPD are characterized by impaired oxidative phosphorylation, early activation of anaerobic glycolysis and excessive lactate and hydrogen ion production with exercise. But the cause of exercise limitation in patients with chronic lung disease without hypoxia has not been known. In order to evaluate the change in the skeletal muscle metabolism as a possible cause of the exercise limitation in chronic lung disease patients without hypoxia, we compared the muscular metabolic data of seven male patients which had been derived from noninvasive $^{31}P$ magnetic resonance spectroscopy(MRS) with those of five age-matched normal male control persons. $^{31}P$ MRS was studied during the sustained isometric contraction of the dominant forearm flexor muscles up to the exhaustion state and the recovery period. Maximal voluntary contraction(MVC) force of the muscle was measured before the isometric exercise, and the 30% of MVC force was constantly loaded to each patient during the isometric exercise. There were no differences of intracellular pH (pHi) and inorganic phosphate/phosphocreatine(Pi/PCr) at baseline, exhaustion state and recovery period between two groups. But pHi during the exercise was lower in patients group than the control group (p < 0.05). Pi/PCr during the exercise did not show significant difference between two groups. These results suggest that the exercise limitation in chronic lung disease patients without hypoxia also could be attributed to the abnormalities in the skeletal muscle metabolism.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1263-1270
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• 1997

Background : Differentiation of malignity and benignity is crucial for management of solitary pulmonary nodule(SPN). Clinical parameters such as patient's age, nodule size, smoking history, doubling time, typical calcification in X-ray and CT findings have been reported as helpful in this purpose. However, in most cases, these parameters are not conclusive. Glucose metabolism is increased in cancer tissues including lung cancer tissues. After uptake of 2-[F-18]-fluoro-2-deoxy-D-glucose(FDG), the glucose analogue, by cancer cell, FDG is trapped in the cell without further metabolism after phosphorylation. Thus, hypermetabolic focus in FDG-positron emission tomography (PET) imaging suggest malignancy. We evaluated the diagnostic efficacy of FDG-PET imaging in distinguishing malignant and benign SPN. Methods : We evaluated 28 patients with SPN from Jan. 1995 to Jan. 1997. CT scan of chest and whole-body FDG-PET imaging were performed in all patients. Histologic diagnosis was confirmed by transthoracic fine needle aspiration and biopsy, bronchoscopic biopsy and open thoracotomy. Results : Of the 28 SPN's, 22 nodules were malignant and 6 nodules were benign. FDG-PET imaging diagnosed all malignant nodules correctly as positive, and diagnosed 4 of 6 benign nodules correctly as negative. One tuberculous granuloma and one aspergilloma showed hypennetabolic focus and were diagnosed falsely positve with FDG-PET imaging. In the diagnosis of SPN with FDG-PET, sensitivity and specificity were 100% and 66.7%, positive predictive value and negative predictive value were 92% and 100%. Conclusion : FDG-PET imaging is highly useful noninvasive diagnostic tool in distinguishing between malignant SPN and benign SPN.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.163-168
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• 2007

Background: Temporomandibular joint disorder (TMD) is a group of musculoskeletal conditions characterized by pain in the pre-auricular area, limitation of jaw movement and palpable muscle tenderness. Thermography is a nonionizing, noninvasive diagnostic alternative for the evaluation of TMD. This study was conducted to evaluate the usefulness of thermography in the assessment of TMD. Methods: Thermography was conducted on the 61 patients who had been diagnosed with TMD, and on the 34 normal symptom-free volunteers. The temperature differences between opposite sides of the temporomandibular joint (${\Delta}T_{TMJ}$) and the masseter muscle (${\Delta}T_{MST}$) were calculated. The sensitivity and specificity of thermography was calculated at the cut off values of 0.2, 0.3, and $0.4^{\circ}C$. Results: In the patient group, the ${\Delta}T_{TMJ}$ was $0.42{\pm}0.38^{\circ}C$ and the ${\Delta}T_{MST}$ was $0.38{\pm}0.33^{\circ}C$, whereas in the control group the ${\Delta}T_{TMJ}$ was $0.10{\pm}0.07^{\circ}C$ and the ${\Delta}T_{MST}\;0.15{\pm}0.10^{\circ}C$. In addition, the patient group demonstrated a significantly lower level of thermal symmetry than the control group (P < 0.001) in both the temporomandibular joints and the masseter muscles. The sensitivity of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 67.2, 49.2, and 42.6% in the temporomandibular joint (TMJ) and 60.7, 49.2 and 37.7% in the masseter muscle, respectively. The specificity of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 88.2, 100, and 100% in the TMJ and 61.8, 91.2 and 100% in the masseter muscles, respectively. The accuracy of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 74.7, 67.4, and 63.2% in TMJ and 61.1, 64.2 and 60.0% in the masseter muscles, respectively. Conclusions: Temperature differences exist between the opposite sides of the TMD and masseter muscles in patients with TMD. Although the sensitivity of thermography in the diagnosis of TMD is low, it has high specificity in the evaluation of TMD, and is therefore applicable to patients with TMD.

• The Korean Journal of Nuclear Medicine
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• v.36 no.4
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• pp.261-270
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• 2002

Purpose: Nicotinic acetylcholine receptors (nAChRs), which mediate excitatory neurotransmission, are known to participate in various neurophysiological functions. Severe losses of nAChRs have been noted in Alzheimer's and Parkinson's diseases. Therefore, noninvasive and quantitative imaging of nAChRs would offer a better understanding on the function of these receptors. In this study, $2-[^{18}F]fluoro-A85380\;([^{18}F]1)$, an ${\alpha}_4{\beta}_2$ nAChRs radioligand, was prepared using one HPLC purification and evaluated in mouse brain, and the results were compared with those in the literature. Materials and Methods: $[^{18}F]1$ was prepared by $[^{18}F]$fluorination of the iodo precursor followed by acidic deprotection and then purified by HPLC. Tissue distribution studies were performed in mouse brain at the indicated time points and the result was expressed as %ID/g. Inhibition studies were also carried out with pretreatment of various ligands. Results: One HPLC purification method gave the desired product in 15-20% radiochemical yield and with high specific activity ($38-55GBq/{\mu}mol$). Tissue distribution studies showed that $[^{18}F]1$ specifically labeled nAChRs in mouse brain with a high thalamus to cerebellum uptake ratio (13.8 at 90 min). Inhibition studios demonstrated selective binding of $[^{18}F]1$ to nAChRs, blocking the uptake of the $[^{18}F]1$ in nAChR-rich legions by selective ligands such as cytisine and nicotine which are well-known nAChRs agonists. Conclusion: This study demonstrated that the $[^{18}F]1$ produced by the method using one HPLC purification gave the results similar to those reported in the literature. Therefore, this synthetic method can be readily applied to the routine preparation of $[^{18}F]1$, a PET radioligand for ${\alpha}_4{\beta}_2$ nAChRs imaging.