Research on zirconium alloys with low elastic modulus and low magnetic susceptibility for improving bone resorption and susceptibility artifacts / 대한치과재료학회지

The objective of this study was to fabricate Zr-Cu alloys with low elastic modulus and low magnetic susceptibility for the use as the dental biomaterials. Metallic implants, such as stainless steel, Co-Cr alloys, and Ti alloys, could be magnetized in the strong magnetic field of the MRI instrument and produce artifacts (magnetic susceptibility artifacts) on the image. The areas that cause the artifacts on images are closely related to the magnetic susceptibility. This susceptibility artifact is caused by metals, such as Ti, Co, and stainless steels, inside the body. Therefore, metallic implants with a low magnetic susceptibility are preferable for surgery performed with the assistance of an MRI. Recently, Zr-based alloys have been attracting interests as biomaterials due to their excellent mechanical properties and low magnetic susceptibility. The magnetic susceptibility of Zr-Nb was half that of Ti-6Al-4V. In addition, the magnetic susceptibility of Zr-Mo was reported almost one-third that of commercially pure Ti and Ti-6Al-4V alloy.However, there are limited reports concerning metallic biomaterials with low magnetic susceptibility for dental applications. The magnetic susceptibility of the Zr-Cu binary alloys was extremely low, approximately 10-7 ; this level is approximately one order less than that of pure Zr and other commercialized Ti-based metallic biomaterials. The Zr-Cu binary alloy exhibited moderate compressive strength (1261~1565 MPa), yield stress (432~595 MPa), favorable elongation (14~34%), high elastic energy (7.2~19.3 MJ/㎥ ) and low elastic modulus (20~28 GPa). Consequently, Zr-Cu binary alloys have the potential to be used as biomaterials with nullifying magnetic properties for magnetic resonance imaging diagnosis and a good combination of mechanical properties indicates them potential biomaterials for biological hard tissue materials

Research on zirconium alloys with low elastic modulus and low magnetic susceptibility for improving bone resorption and susceptibility artifacts / 대한치과재료학회지

The objective of this study was to fabricate Zr-Cu alloys with low elastic modulus and low magnetic susceptibility for the use as the dental biomaterials. Metallic implants, such as stainless steel, Co-Cr alloys, and Ti alloys, could be magnetized in the strong magnetic field of the MRI instrument and produce artifacts (magnetic susceptibility artifacts) on the image. The areas that cause the artifacts on images are closely related to the magnetic susceptibility. This susceptibility artifact is caused by metals, such as Ti, Co, and stainless steels, inside the body. Therefore, metallic implants with a low magnetic susceptibility are preferable for surgery performed with the assistance of an MRI. Recently, Zr-based alloys have been attracting interests as biomaterials due to their excellent mechanical properties and low magnetic susceptibility. The magnetic susceptibility of Zr-Nb was half that of Ti-6Al-4V. In addition, the magnetic susceptibility of Zr-Mo was reported almost one-third that of commercially pure Ti and Ti-6Al-4V alloy.However, there are limited reports concerning metallic biomaterials with low magnetic susceptibility for dental applications. The magnetic susceptibility of the Zr-Cu binary alloys was extremely low, approximately 10-7 ; this level is approximately one order less than that of pure Zr and other commercialized Ti-based metallic biomaterials. The Zr-Cu binary alloy exhibited moderate compressive strength (1261~1565 MPa), yield stress (432~595 MPa), favorable elongation (14~34%), high elastic energy (7.2~19.3 MJ/㎥ ) and low elastic modulus (20~28 GPa). Consequently, Zr-Cu binary alloys have the potential to be used as biomaterials with nullifying magnetic properties for magnetic resonance imaging diagnosis and a good combination of mechanical properties indicates them potential biomaterials for biological hard tissue materials

Inhibition of STAT3 signaling induces apoptosis and suppresses growth of lung cancer: good and bad / 한국실험동물학회지

Signal transducer and activator of transcription 3 (STAT3) modulates a variety of genes involved in the regulation of critical functions, including cell proliferation, differentiation, apoptosis, angiogenesis, metastasis, and immunity. For many cancers, elevated levels of STAT3 signaling have been associated with a poor prognosis and the development of chemotherapy resistance. In this study, we investigated the inhibitory effects of a novel small-molecule inhibitor of STAT3, STX-0119, on the cell viability and survival of human lung cancer cells. STX-0119 inhibited activated STAT3 and the expression of STAT3-regulated oncoproteins such as c-Myc, cyclin D1, and survivin in lung cancer cells. STX-0119 also decreased the amount of STAT3 in the nuclear fraction as well as induced apoptosis of these lung cancer cell lines as evidenced by increases in apoptotic cells (Annexin V positive) and poly (ADP-ribose) polymerase (PARP) cleavage. The efficacy of STX-0119 in a mouse xenograft model was confirmed. However, a hematological side effect, which had not been previously reported, was observed. The level of white blood cells was significantly lowered when treated at the dose at which STX-0119 alone showed a significant tumor-suppressive effect. In conclusion, we suggest that STX-0119 may be a potent therapeutic agent against lung cancer. Consideration of the side effect suggests, it is necessary to study whether low-dose STX-0119 is effective for lung treatment with a combination of classic lung cancer therapeutics.

Effect of Surface Roughness on the Mechanical Properties of Ceramic-Polymer Blocks for CAD/CAM Dental Restoration / 대한치과재료학회지

The effect of surface roughness of ceramic-polymer CAD/CAM blocks on the mechanical properties was investigated in this study. Commercially available Polyglass (Vericom, Korea) and Enamic (Vita, Germany) were selected for this purpose. They were cut into either (4.0×2.1×17.0) mm and (3.0×4.0×17.0) mm, followed by grinding, and polished sequentially with 6 µm and 1 µm diamond paste. Flexural strength, fracture toughness, and Weibull analysis were determined according to ISO 6872 Dentistry-Ceramic materials. The elastic moduli were calculated from a stress-strain curves under flexural loading. The statistical significances of the mechanical properties between the products and surface roughness were analyzed with ANOVA and pared t-test at a significance level of 0.05. After grinding with 6 µm diamond paste after cutting by observing with an atomic force microscope, the arithmetic average roughness decreased to 47~49% and the maximum roughness decreased to 68~69%. When polishing with 1 µm diamond paste, The average roughness decreased to 13~22% and the maximum roughness decreased to 16~19%. When the flexural load was applied, stress increased linearly and fractured without plastic deformation both Polyglass and Enamic. As the surface roughness decreased, the mechanical properties were increased both Polyglass and Enamic. However, the mechanical properties of Polyglass increased up to P3, while Enamic showed almost maximal values at E2, after that there was no significant differences between E2 and E3. It could be due to the different microstructure between two blocks used in this experiment.

Characteristics of urinary retention in female inpatients managed with medical treatments

PURPOSE: We aimed to analyze the characteristics of urinary retention (UR) in female inpatients managed with medical treatments. MATERIALS AND METHODS: We retrospectively analyzed the medical records of female inpatients referred to the department of urology for UR at our institution from January 2009, to December 2014. UR was defined as a difficulty in self-voiding despite a sufficient urine volume or >300-mL postvoid residual. The data included patients' age, body mass index (BMI), ambulatory status, medical and surgical history, classes of taking drugs, and urinary tract infection. RESULTS: A total of 182 women were included as retention group, mean age of 72.64±12.94 years and BMI of 22.94±3.10 kg/m2. In the chi-square analysis, cardiovascular disorders (p=0.000), diabetes mellitus (p=0.008), metastatic malignancy (p=0.008), chronic renal disorders (p=0.028) were found significantly. In the multiple logistic regression analysis, cardiovascular disorders (p=0.002; odds ratio [OR], 0.491), metastatic malignancy (p=0.013; OR, 2.616) were found to increase the risk of UR. The most common surgical history was anti-incontinence surgery (7.2%). In term of medication use, the most prescribed agents were nonsteroidal anti-inflammatory drugs (NSAIDs) (53.8%). The patients taking multiple drugs with antimuscarinic effects except of NSAIDs, narcotics and diuretics were 48 (26.4%). Urinary tract infection was identified in 43 patients (23.6%). CONCLUSIONS: UR in females managed with medical treatments could be occurred occasionally. We think that thorough attentions are needed for UR to patients with cardiovascular disorders including diabetes mellitus, metastatic malignancy, chronic renal disorders urinary tract infection, and more careful interests when managing with drugs with antimuscarinic effects.

The Prostate Cancer Detection Rate on the Second Prostate Biopsy according to Prostate-Specific Antigen Trend

PURPOSE: To identify the prostate cancer detection rate on the patients who had second prostate biopsy out of the patients who were reported negative in their first biopsy. MATERIALS AND METHODS: From July 2006 to February 2012, prostate biopsy was performed on 843 patients with over 4 ng/ml and on 618 biopsy negative patients PSA was performed from between 6 months and 9 months after biopsy. On 164 patients, second biopsy was performed, and 42 patients were selected. If there was less than 10% change between PSA before the prostate biopsy and PSA measured during 6 to 9 months after the first biopsy it was considered as no change. If above 10% increase, it was considered increase and if above 10% decrease it was considered as decrease. RESULTS: The cancer detection rate in PSA increase group was 20%, the detection rate in no change in PSA level but still over the normal range group 8.3%, and that in the PSA decrease group was 0%. When comparing prostate cancer group and non-cancer group, it is more probable to have prostate cancer when they are older, prostate volume is smaller and PSA density is higher. CONCLUSIONS: The second biopsy is strongly recommended when PSA level shows no change or increase, age is older, prostate volume is smaller or PSA density is higher.

Permanent Preserving the Bony Fragments Digged Up from Haemi Nameless Martyrdom Holy Place Burial Sites / 체질인류학회지

Bone materials diggd up from the Haemi nameless martyrdom holy place burial sites were severely broken into fragments of various size, clay matrix filled the bone marrow cavities, grass roots were spreaded into the periosteum and the fragments were very soft enough to be flaken. To make permanent specimens, bony fragments impregnated within unsaturated polyester resin with catalyzer MEKP, promotor 8% cobalt octoate, and UV absorber. Permanent specimens were so very transparent that all the macroscopic structures can be observed, and they were hard enough not to be broken or cracked. This method of preserving bony fragments is considered to be used in archaeologic preservation and in making teaching materials of various human organs or tissues.

Review of 10 Cases of Pyogenic Epidural Abscess of the Spine

Spinal epidural abscess is a rare disorder with poor prognosis. In order to understand its clinical feature and method of treatment, a retrospective study of spinal epidural abscess spanning 8 years and encompassing 10 patients was done. There were 6 males and 4 females aged 12 to 64 years with peak incidence at the sixth decade. In one patient, epidural abscess recurred at the site previously treated 10 years ago. In addition to fever and leukocytosis in 8 patients, other frequent symptoms according to lesion site were abdominal pain and motor weakness in thoracic epidural abscess and low back pain and sciatica in lumbar epidural abscess. Staphylococcus aureus was the most common causative organism. Magnetic resonance imaging(MRI) showed variable signal on T1-weighted images and hyperintensity on T2-weighted images, which was studied in 6 patients. Two patterns in gadolinium-enhanced MRI were a central focus of low signal intensity surrounded by ring enhancement(2 patients) gadolinium-enhanced MRI were a central focus of low signal intensity surrounded by ring enhanement(2 patients) and heterogeneous enhancement(4 patients). MRI offered the advantage of noninvasive early recognition and anatomical localization, which made it the imaging modality of choice. Although laminectomy was the standard operative procedure, the result of window laminectomy with catheter drainage for prevention of kyphosis was proven effective in a girl. Complete improvement following surgery was obtained in patients, while a man resulted in paraplegia and a boy paraparesis with mild kyphosis in thoracic abscess as sequelae.

Clinical Analysis of Intracranial Epidermoid and Dermoid Tumors

We reviewed 6 epidermoid and 3 dermoid tumors of the brain treated surgically for a period of 4 years. The favorite sites for epidermoids were the cerebellopontine angle, whereas dermoids were found in the cerebellar vermis. The average age was 44.2 years for the patients with epidermoid tumors and 24.6 years for the patients with dermoid tumors. Average duration of symptoms was much shorter in dermoids than in epidermoids. Computed tomography scans revealed hypodense lesions with irregular borders without contrast enhancement. Magnetic resonance imaging was performed on 3 patients;the tumors showed decreased signal intensity relative to the brain on T1-weighted images and increased signal intensity relative to the brain on T2-weighted studies. Five were removed totally and 4 subtotally. Aseptic meningitis and transient facial nerve palsy were causes of postoperative morbidity.