A defective HIV-1 helper virus DNA, pHyPC, was assembled by deleting the RNA packaging signal, env, nef and the 3'LTR sequences. HIV-1 like virus particles that carry the HIV-1 receptor, CD4 were generated by coexpression of pHyPC and plasmid DNAs encoding different chimeric CD4 proteins. The CD4 particles, sharing the CD4 ectodomain, precisely fused to different membrane anchors. CD4(+) particles specifically bound to HIV-1 Env expressing cells, but any signs of infection into these cells were not detected. Binding was only partially blocked by either polyclonal anti-CD4 antibodies or by high concentrations of soluble CD4. Suprisingly, CD4(+) particles also adsorbed to HeLa, CHO, NIH3T3 and COS-7 cells in the absence of HIV-1 Env expression. Adsorption was comparable in strength and speed to the highly specific CD4-Env interaction. CD4(-) particles exhibited only background levels of binding. Cell binding was CD4- dependent, but it was independent of the cell type from which the CD4(+) particles originated. Interestingly, CD4-dependent/Env-independent binding was only found when CD4 was present on virus particles. This suggests that the micro-environment of CD4 on virus particles uniquely expose this new cell binding activity. Its high affinity could explain in part why infection of Env(+) cells by CD4(+) particles was not detected. Further experiments will be required to evlauate whether this strong membrane interaction could represent one step in the multiple-step viral entry process.
Adsorption ; Animals ; Antibodies ; COS Cells ; DNA ; Helper Viruses ; HIV-1* ; Membranes ; Plasmids ; Product Packaging ; RNA ; Virion

PURPOSE: The purpose of this study is to correlate the MR findings with clinical stage and clinical outcome, and to describe the evolutional changes of abnormal MR findings of transverse myelitis. MATERIALS AND METHODS: Medical records and spinal MR images of 23 patients with both clinical and radiological diagnosis of transverse myelitis were retrospectively reviewed. MR findings were correlated with clinical stages including interval between MR imaging and full development of clinical symptoms, and compared with the clinical outcome. RESULTS: Diffuse high signal intensity of the spinal cord on T2-weighted image with mild cord bulging (67%) and focal contrast enhancement of the cord (75%) were observed within the first four weeks after full development of clinical symptoms. The findings decreased in extent or vanished later than four weeks on either initial or follow-up MR images. Most patients with either cord atrophy or focal hemorrhagewithin the cord lesion had poor clinical outcome. CONCLUSION: The MR findings of transverse myelitis are nonspecific, which may be seen in a variety of diseases. Serial MRIs, especially follow up examination over at least one month after full development of clinical symptoms are useful in the diagnosis of transverse myelitis and predicting its prognosis.
Atrophy ; Diagnosis ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Medical Records ; Myelitis, Transverse* ; Prognosis ; Retrospective Studies ; Spinal Cord

No abstract available.
Down Syndrome*

We report a case of meningeal hemangiopericytoma presenting as metastasis in the vertebral body and pedicle of the thoracic spine. Hemangiopericytoma is a rare vascular neoplasm. Although the tumor has a strong propensity for both local recurrence and extracranial metastasis, metastasis to thoracic spine is very rare and only two cases were found in the literature. A 44-year-old woman with paraparesis and pain in the thoracic and lower legs was examined by plain radiographs and magnetic resonance imaging. The intracranial hemangiopericytoma was operated 3 years ago. Magnetic resonance imaging demonstrated a tumor invading the left vertebral body and pedicle of the 11th thoracic spine, and compressing the dural sac. The patient was gradually improved after surgical removal of the lesions and the histologic findings were characteristics of hemangiopericytoma.
Adult ; Female ; Hemangiopericytoma* ; Humans ; Leg ; Magnetic Resonance Imaging ; Neoplasm Metastasis* ; Paraparesis ; Recurrence ; Spine* ; Vascular Neoplasms

PURPOSE: This study was to evaluate the effect of rinsing time on the accuracy of interim crowns fabricated by digital light processing. MATERIALS AND METHODS: The maxillary right first molar master die was duplicated using a silicone material, while a study die was produced using epoxy resin. Scans of the epoxy resin die were used in combination with CAD software to design a maxillary right first molar interim crown. Based on this design, 24 interim crowns were fabricated with digital light processing. This study examined the trueness and precision of products that were processed with one of the three different postprocessing rinsing times (1 min, 5 min, and 10 min). Trueness was measured by superimposing reference data with scanned data from external, intaglio, and marginal surfaces. Precision was measured by superimposing the scan data within the group. The trueness and precision data were analyzed using KruskalWallis, nonparametric, and post-hoc tests, and were compared using a MannWhitney U test with Bonferroni correction (α=.05). RESULTS: The trueness of the external and intaglio surfaces of crowns varied significantly among the different rinsing times (P=.004, P=.003), but there was no statistically significant difference in terms of trueness measurements of the marginal surfaces (P=.605). In terms of precision, statistically significant differences were found among the external, intaglio, and marginal surfaces (P=.001). CONCLUSION Interim crowns rinsed for 10 minutes showed high accuracy.

PURPOSE: This study aimed to compare the accuracy (trueness and precision) of interim crowns fabricated using DLP (digital light processing) according to postcuring time. MATERIALS AND METHODS: A virtual stone study die of the upper right first molar was created using a dental laboratory scanner. After designing interim crowns on the virtual study die and saving them as Standard Triangulated Language files, 30 interim crowns were fabricated using a DLP-type 3D printer. Additively manufactured interim crowns were post-cured using three different time conditions-10-minute post-curing interim crown (10-MPCI), 20-minute postcuring interim crown (20-MPCI), and 30-minute post-curing interim crown (30-MPCI) (n = 10 per group). The scan data of the external and intaglio surfaces were overlapped with reference crown data, and trueness was measured using the best-fit alignment method. In the external and intaglio surface groups (n = 45 per group), precision was measured using a combination formula exclusive to scan data (10 C2). Significant differences in accuracy (trueness and precision) data were analyzed using the Kruskal-Wallis H test, and post hoc analysis was performed using the Mann-Whitney U test with Bonferroni correction (α=.05). RESULTS: In the 10-MPCI, 20-MPCI, and 30-MPCI groups, there was a statistically significant difference in the accuracy of the external and intaglio surfaces (P <.05). On the external and intaglio surfaces, the root mean square (RMS) values of trueness and precision were the lowest in the 10-MPCI group. CONCLUSION Interim crowns with 10-minute post-curing showed high accuracy.

PURPOSE: This study aimed to compare the accuracy (trueness and precision) of interim crowns fabricated using DLP (digital light processing) according to postcuring time. MATERIALS AND METHODS: A virtual stone study die of the upper right first molar was created using a dental laboratory scanner. After designing interim crowns on the virtual study die and saving them as Standard Triangulated Language files, 30 interim crowns were fabricated using a DLP-type 3D printer. Additively manufactured interim crowns were post-cured using three different time conditions-10-minute post-curing interim crown (10-MPCI), 20-minute postcuring interim crown (20-MPCI), and 30-minute post-curing interim crown (30-MPCI) (n = 10 per group). The scan data of the external and intaglio surfaces were overlapped with reference crown data, and trueness was measured using the best-fit alignment method. In the external and intaglio surface groups (n = 45 per group), precision was measured using a combination formula exclusive to scan data (10 C2). Significant differences in accuracy (trueness and precision) data were analyzed using the Kruskal-Wallis H test, and post hoc analysis was performed using the Mann-Whitney U test with Bonferroni correction (α=.05). RESULTS: In the 10-MPCI, 20-MPCI, and 30-MPCI groups, there was a statistically significant difference in the accuracy of the external and intaglio surfaces (P <.05). On the external and intaglio surfaces, the root mean square (RMS) values of trueness and precision were the lowest in the 10-MPCI group. CONCLUSION Interim crowns with 10-minute post-curing showed high accuracy.

BACKGROUND: Legionella pneumophila has been recognized as an important cause of community-acquired pneumonia(CAP) requiring hospitalization. However, epidemiological data on the occurrence of legionella-related pneumonia is unavailable in Korea. The purpose of this study was to evaluated the etiological imprtance of legionella pneumophila serogroup 1 in patients hospitalized with CAP. METHOD: The CAP patient over 16 year-old were recruited from July 1999 to June 2000 at the Chunchon Sacred Heart Hospital. Fifty four patients (male 29, female 25, average age 63.8±15.3) were included in this study. A diagnosis of a legionella pneumophila infection was based on a urinary antigen test using the Binax Company enzyme immunoassay. The severity of pneumonia was assessed using the Fine's PORT scoring system. RESULT: The average Fine's PORT score was 99.7(±44.9). According to the risk classification proposed by the Infectious Disease Society of America, the number of patients in each class(from class I to class V) were 6(11.1%), 13(24.1%), 9(16.7%), 14(25.8%), and 12(22.2%), respectively. Thirty two patients(59.3%) were initially admitted to the intensive care unit. The mortality rate was 16.7%(9 in 54). In all patients, urinary antigens to Legionella pneumophila serogroup 1 were not detected. CONCLUSION: Legionella pneumophila may play little role in causing adult CAP in Korea. Therefore, the routine use of macrolide in the empirical treatment of the CAP patients based upon the ATS guidelines(1993) in Korea should be reevaluated.
Adult ; Americas ; Classification ; Communicable Diseases ; Diagnosis ; Female ; Gangwon-do ; Heart ; Hospitalization ; Humans ; Immunoenzyme Techniques ; Intensive Care Units ; Korea* ; Legionella pneumophila* ; Legionella* ; Legionnaires' Disease ; Mortality ; Pneumonia*

PURPOSE: To investigate the prevalence of paralytic ileus after spinal operation in the supine or prone operative position and to determine the efficacy of prophylactic gastrointestinal motility medications in preventing symptomatic paralytic ileus after a spinal operation. MATERIALS AND METHODS: All patients received spinal surgery in the supine or prone operative position. The study period was divided into two phases: first, to analyze the prevalence of radiographic and symptomatic paralytic ileus after a spinal operation, and second, to determine the therapeutic effects of prophylactic gastrointestinal motility medications (postoperative intravenous injection of scopolamine butylbromide and metoclopramide hydrochloride) on symptomatic paralytic ileus after a spinal operation. RESULTS: Basic demographic data were not different. In the first phase of this study, 27 patients (32.9%) with radiographic paralytic ileus and 11 patients (13.4%) with symptomatic paralytic ileus were observed. Radiographic paralytic ileus was more often noted in patients who underwent an operation in the prone position (p=0.044); whereas the occurrence of symptomatic paralytic ileus was not different between the supine and prone positioned patients (p=0.385). In the second phase, prophylactic medications were shown to be ineffective in preventing symptomatic paralytic ileus after spinal surgery [symptomatic paralytic ileus was observed in 11.1% (4/36) with prophylactic medication and 16.7% (5/30) with a placebo, p=0.513]. CONCLUSION: Spinal surgery in the prone position was shown to increase the likelihood of radiographic paralytic ileus occurrence, but not symptomatic paralytic ileus. Unfortunately, the prophylactic medications to prevent symptomatic paralytic ileus after spine surgery were shown to be ineffective.
Adjuvants, Anesthesia/*administration & dosage/pharmacology ; Adult ; Aged ; Antiemetics/*administration & dosage/pharmacology ; Female ; Gastrointestinal Motility/*drug effects/physiology ; Humans ; Injections, Intravenous ; Intestinal Pseudo-Obstruction/drug therapy/epidemiology/*prevention & control ; Lumbar Vertebrae/radiography/*surgery ; Male ; Metoclopramide/*administration & dosage/pharmacology ; Middle Aged ; Postoperative Complications/epidemiology ; Prevalence ; Prone Position ; Prospective Studies ; Republic of Korea ; Scopolamine Hydrobromide/*administration & dosage/*pharmacology ; Spinal Fusion/*adverse effects ; Supine Position ; Treatment Outcome

PURPOSE: Percutaneous epidural neuroplasty (PEN) is a minimally invasive treatment. The efficacy of PEN has been relatively well investigated; however, the relationship between the clinical effectiveness of PEN and the severity of spinal canal stenosis by disc material has not yet been established. The purpose of this study was to compare clinical outcomes of PEN according to the dural sac cross-sectional area in single level disc disease. MATERIALS AND METHODS: This study included 363 patients with back pain from single level disc disease with and without radiculopathy. Patients were categorized into groups according to spinal canal compromise by disc material: Category 1, less or more than 50%; and Category 2, three subgroups with lesser than a third, between a third and two thirds, and more than two thirds. Clinical outcomes were assessed according to the Visual Analog Scale (VAS) score for back pain and leg pain and Odom's criteria at 1, 3, 6, 12, and 24 months after treatment. RESULTS: The demographic data showed no difference between groups according to spinal canal compromise by disc material except age (older age correlated with more spinal canal compromise). The dural sac cross-sectional area did not correlate with the VAS scores for back and leg pain after PEN in single level disc disease in Groups 1 and 2. Odom's criteria after PEN were also not different according to dural sac cross-sectional area by disc material. CONCLUSION: PEN is an effective procedure in treating single level lumbar disc herniation without affecting dural sac cross-sectional area.
Adult ; Aged ; Back Pain/etiology/*surgery ; Dura Mater/*pathology ; Female ; Humans ; Intervertebral Disc ; Intervertebral Disc Displacement ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Reconstructive Surgical Procedures ; Spinal Stenosis/complications/*pathology ; Tissue Adhesions/*surgery ; Treatment Outcome ; Visual Analog Scale