Occult HBV infection (OBI) is defined as presence of HBV DNA in the liver tissue in patients with serologically undetectable HBsAg. There are differences in virologic and serological profiles of OBI. Majority of OBI are positive for anti-HBs and/or anti-HBc and minor portion are negative for all HBV markers. However, there are no HBV mutations in the surface and its regulatory regions. HBV infection persists by the presence of covalently closed circular DNA (cccDNA) within the infected hepatocytes, which serves as a reservoir for future infection. OBI increases the risk of HBV transmission through transfusion, hemodialysis, and organ transplantation. Therefore effective measures should be employed to screen OBI. Antiviral therapy is needed in HBsAg-negative transplant patients who are anti-HBc positive to prevent the recurrence of HBV infection. Since HBV replication is strongly suppressed by immune surveillance system in OBI patients, immunosuppression results in massive HBV replication. This leads to acute hepatitis and sometimes mortality when immune surveillance is recovered after stopping immunosuppressive drugs/anticancer chemotherapy. Therefore, narrow surveillance is required to recognize the viral reactivation and start antiviral agents during immunosuppressive therapy/anticancer chemotherapy in patients with OBI.
Blood Transfusion ; DNA, Viral/analysis ; Hepatitis B/*diagnosis/transmission ; Hepatitis B Core Antigens/immunology ; Hepatitis B virus/genetics/*physiology ; Humans ; Liver Transplantation ; Renal Dialysis ; Virus Activation

No abstract available.
Lung*

No abstract available.
Thumb*

No abstract available.
Animals ; Antibodies, Neutralizing* ; Immunization* ; Mice*

No abstract available.
Cytomegalovirus* ; Humans* ; Immunoassay*

Generalized lymphangiomatosis is a rare congenital malformation of the lymphatics. CT and MR scan have been used to evaluate lymphangiomas, which appear as large multicystic fluid-filled masses. CT and MR Imaging findings are often helpful in distinguishing lymphangiomas from various vascular disorders. We report the findings of CT, MRI and bone scan in a patient with generalized cystic lymphangiomatosis. Whole body 3.0-T MR scan using STIR sequence with a larger FOV could detect the additional lesions that were not seen at other imaging modalities. We believe that whole body 3.0 T MR imaging is a good modality to evaluate the extent of the disease and following up the patients with the generalized cystic lymphangiomatosis.
Humans ; Lymphangioma

OBJECTIVE: The survey was conducted to improve the health of Korean adolescents and to prepare adequate teaching programs by investigating their sexual behavior. METHODS: The participants of the survey was 80,000 middle and high school students aged 13 to 18. The survey was conducted from September 1st, 2007 to September 22nd, 2007. RESULTS: 78,834 students were surveyed and 74,698 (94.8%) students responded the survey. 35,232 (47.2%) of respondents were male students and 39,466 (52.8%) of respondents were female students. 38,820 (52.0%) of respondents were middle school students, 25,051 (33.5%) of respondents were high school students and 10,827 (14.5%) of respondents were technical high school students. 5.2% of respondents experienced sexual intercourse. The average age of the first sexual intercourse was 14.2 years old. 1.0% of respondents had a sexual intercourse before they enter the middle school. The pregnancy rate was 0.3%. Among respondents who experienced sexual intercourse, the rate of the use of contraceptive methods was 38.2%. The rate of using inappropriate contraceptive methods was 21.6%. The average age of a first wet dream for boys was 13.2 years old. The average age of menarche for girls was 12.4 year old. The rate of respondents who had a sex education was 72.2%. CONCLUSION: The average age of the first wet dream and menarche had been decreased. The average age of the first sex experience among adolescents had been decreased. The rate of adolescents who experienced a sexual intercourse was increased. However, the rate of using reliable contraceptive methods was very low. Therefore, adequate sex educations including effective contraceptive methods needs to be conducted to prevent unwanted pregnancy of adolescents.
Adolescent ; Aged ; Coitus ; Contraception ; Surveys and Questionnaires ; Dreams ; Female ; Humans ; Male ; Menarche ; Pregnancy ; Pregnancy Rate ; Pregnancy, Unwanted ; Sex Education ; Sexual Behavior

OBJECTIVE: This research was performed to improve the health of Korean adolescents and to prepare adequate teaching programs by investigating their sexual cognition and behavior and preparing for adequate programs. METHODS: We conducted a survey of eighty thousand middle and high school students whose ages range from 13 to 18, during the period of September 1st, 2006 to October 30th, 2006. RESULTS: 78,593 people are polled and 71,404 people responded. Accordingly, the response rate was 90.0%: 52.1% (37,204) of the respondents were boys and 47.9% (34,200) were girls; 52.4% (37,420) of respondents were middle school students, 32.9% (23,500) of them were high school students, and 14.7% (10,479) of them were technical high school students. The rate of respondents who had experienced sexual relationship was 5.1%. The average age of starting sexual relationship was 14.2 year old. The rate of respondents who had experienced sexual relationship before they go to the middle school was 1.0%. The rate of pregnancy experience was 0.5%. The rate of respondents who were using a contraceptive method was 38.1%. The average boys age of having the first wet dream was 13.1 years old and girls of starting menstruation was 12.5 year old. The rate of using inappropriate contraception was 24.3%. The rate of having a sex education per a year was 62.0%. CONCLUSION: This research shows that the rate of adolescents who are experiencing sexual relationship is increasing. Besides, the age of adolescents starting sexual relationship is decreasing as their age of starting wet dream and menstruation decreases. As a result, it is strongly asserted that adequate sex education programs are indispensable to adolescents.
Adolescent ; Cognition ; Contraception ; Surveys and Questionnaires ; Dreams ; Female ; Humans ; Menstruation ; Pregnancy ; Sex Education ; Sexual Behavior

Iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) is a recently developed method for robust separation of fat and water with very high signal-to-noise-ratio (SNR) efficiency. In contrast to conventional fat-saturation methods, IDEAL is insensitive to magnetic field (B0 and B1) inhomogeneity. The aim of this study was to illustrate the practical application of the IDEAL technique in reducing metallic artifacts in postoperative patients with metallic hardware. The IDEAL technique can help musculoskeletal radiologists make an accurate diagnosis particularly in musculoskeletal imaging by reducing metallic artifacts, enabling the use of contrast enhancement, improving SNR performance, and providing various modes of MR images with one scan parameter.
Adipose Tissue ; Adult ; Aged ; *Artifacts ; Body Water ; Cartilage, Articular/pathology ; Contrast Media/diagnostic use ; Humans ; Least-Squares Analysis ; Magnetic Resonance Imaging/*methods ; Male ; Metals ; Middle Aged ; Phantoms, Imaging ; *Prostheses and Implants ; Signal-To-Noise Ratio

Transient osteoporosis of the hip (TOH) is a rare disorder of unknown etiology that is characterized by acute onset of disabling bone pain. The locally increased bone turnover and low bone mineral density (BMD) associated with this disorder indicate a potential role for an antiresorptive agent such as bisphosphonate as a treatment. A previously healthy 46-year-old man developed the sudden onset of pain in his right buttock and inguinal area, especially during walking and caused him to limp. A thorough medical workup including X-ray, MRI, and bone SPECT revealed transient osteoporosis of the hip, and he was treated with an infusion of zoledronate (5 mg). Two weeks later, he was fully recovered from pain and the gait disturbance. A follow-up MRI of the hip joint taken after 6 months showed complete resolution. The use of intravenous zoledronate provided a successful outcome in the treatment of TOH. The possibility of TOH should be considered in patients complaining of sudden hip pain and a limping gait. MR imaging played an important role for differentiation of TOH from other aggressive conditions with long term sequelae.
Bone Density ; Buttocks ; Diphosphonates ; Follow-Up Studies ; Gait ; Hip ; Hip Joint ; Humans ; Imidazoles ; Middle Aged ; Osteoporosis ; Tomography, Emission-Computed, Single-Photon ; Walking