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

No abstract available.
Down Syndrome*

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

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*

OBJECTIVE: About 40% of patients who admit to the hospital after subarachnoid hemorrhage are poor clinical grade(Hunt-Hess grade IV, V). The majority of these patients have been excluded from early, aggressive treatment. The current study was undertaken to evaluate the outcome of urgent surgery for Hunt-Hess grade IV aneurysmal subarachnoid hemorrhage. MATERIALS AND METHODS: We reviewed hospital records and radiographic studies of 36 patients who were Hunt-Hess grade IV among 201 cases with ruptured intracranial aneurysm admitted between Sep. 1995 and Dec. 2000. Operated patients were treated with urgent angiography and surgery within 24 hours of presentation, except six patients, and medical records of these patients were reviewed for the clinical course and Glasgow outcome scale(GOS). RESULTS: Overall management results of the 36 patients were good recovery in 13(36.1%), moderate disability in 12 (33.3%), severe disability in 1(2.8%), vegetative state in 1(2.8%) and 9(25.0%) of surgically treated patients had died. CONCLUSION: Although with limited number of patients, we conclude that urgent surgery for Hunt-Hess grade IV patients results in a better neurologic outcome and urgent surgery combined with aggressive postoperative management can minimize mortality.
Angiography ; Hospital Records ; Humans ; Intracranial Aneurysm* ; Medical Records ; Mortality ; Persistent Vegetative State ; Subarachnoid Hemorrhage

It has been suggested that dendritic cells (DCs) are critical antigen presenting cells for eosinophilic airway inflammation in a mouse model of asthma, and cysteinyl leukotrienes may play a role in DC trafficking in asthmatics. We investigated whether the number of DCs is increased in the induced sputum of both atopic and nonatopic asthmatics and is related to activated eosinophil count in the sputum. Sputum was induced by inhalation of hypertonic saline in 9 atopic and 12 nonatopic asthmatics and 10 nonatopic normal controls, and differential cell counts were performed. DCs and activated eosinophils were identified by immunocytochemistry with monoclonal antibodies (anti-CD1a and EG2, respectively). There were significantly higher percentages of eosinophils, EG2+ cells, and CD1a+ DC in the sputum of atopic and nonatopic asthmatics compared with normal controls, respectively. In asthmatics, the percentage of CD1a+ DC was significantly correlated with that of EG2+ cells (Rs=0.62, p=0.004). We demonstrated that the increased number of DCs was evident in the induced sputum of both atopic and nonatopic asthmatics, and the DC number was related to the activated eosinophil count, which suggests that DCs may contribute to the ongoing eosinophilic inflammation in asthmatic airways, and vice versa.
Adult ; Aged ; Antigens, CD1/analysis ; Asthma/*immunology/pathology ; Comparative Study ; Dendritic Cells/*immunology ; Eosinophil Granule Proteins/analysis ; Eosinophils/cytology/*immunology ; Female ; Humans ; Immunohistochemistry ; Leukocyte Count ; Male ; Middle Aged ; Research Support, Non-U.S. Gov't ; Sputum/cytology/*immunology