Biomedical subjects

Thomas Jones

Publications and source records attributed to Thomas Jones.

7 recordsLinked to original sources

PubMed2005

Magnetic resonance imaging is not needed to clear cervical spines in blunt trauma patients with normal computed tomographic results and no motor deficits.

HYPOTHESIS: Trauma patients with normal motor examination results and normal cervical spine helical computed tomographic (CT) scans with sagittal reconstructions do not have significant cervical spine injury. DESIGN: Prospectively collected registry data. SETTING: Level II community-based trauma center. PATIENTS: All patients admitted to the trauma service from January 1, 1999, to December 31, 2003. MAIN OUTCOME MEASURES: Injury detected by CT and/or magnetic resonance imaging (MRI) of the cervical spine. Neurologic examination and need for surgery were secondary outcomes. RESULTS: During the study period, 2854 trauma patients were admitted, of whom 91.2% had blunt trauma. Of these patients, 56.2% had a closed head injury. One hundred patients had cervical spine and/or spinal cord injuries. Eighty-five patients had a cervical spine injury diagnosed by CT. Fifteen patients had admission neurologic deficits not seen on CT, and 7 of these patients had non-bony abnormalities on MRI. Ninety-three patients had a normal admission motor examination result, a CT result negative for trauma, and persistent cervical spine pain, and were examined with MRI. All MRI examination results were negative for clinically significant injury. Seventeen patients had MRIs that showed degenerative disc disease, and 6 had spinal canal stenosis secondary to ossification. Twelve comatose patients (Glasgow Coma Scale score, <9), moving all 4 extremities on arrival, with normal CT results of the cervical spine, were examined with MRI. All of these MRI examination results were negative for injury. None of the patients experienced neurologic deterioration. No patient required operative management of spinal injury. CONCLUSION: Blunt trauma patients with normal motor examination results and normal CT results of the cervical spine do not require further radiologic examination before clearing the cervical spine.

Adult↗

PubMed2005

Cervical spine clearance in blunt trauma: evaluation of a computed tomography-based protocol.

BACKGROUND: Prompt identification of cervical spine injuries has been a critical issue in trauma management. In 1998, the authors developed a new protocol to evaluate cervical spines in blunt trauma. This protocol relies on clinical clearance for appropriate patients and helical computed tomography instead of plain radiographs for patients who cannot be clinically cleared. The authors then prospectively collected data on all cervical spine evaluations to assess the sensitivity and specificity of their approach. METHODS: Any patient without clinical evidence of neurologic injury, alcohol or drug intoxication, or distracting injury underwent cervical spine evaluation by clinical examination. Patients who did not meet these criteria underwent helical computed tomographic scanning of the entire cervical spine. For patients who had neurologic deficits, a magnetic resonance image was obtained. If the patient was not evaluable secondary to coma, the computed tomographic scan was without abnormality, and the patient was moving all four extremities at arrival in the emergency department, the cervical spine was cleared, and spinal precautions were removed. Data were collected for all patients admitted to Santa Barbara Cottage Hospital trauma service between 1999 and 2002. The authors selected for analysis patients with blunt trauma and further identified those with closed head injuries (Glasgow Coma Scale score < 15 and loss of consciousness). In addition, all blunt cervical spine injuries were reviewed. RESULTS: During the period of study, 2,854 trauma patients were admitted, of whom 2,603 (91%) had blunt trauma. Of these, 1,462 (56%) had closed head injuries. One hundred patients (7% of patients admitted for blunt trauma) had cervical spine or spinal cord injuries, of which 99 were identified by the authors' protocol. Only one injury was not appreciated in a patient with syringomyelia. Fifteen percent of patients with spinal cord injury had no radiographic abnormality; all of these patients presented with neurologic deficits. The sensitivity for detecting cervical spine injury was thus 99%, and the specificity was 100%. The risk of missing a cervical spine injury in these blunt trauma patients was 0.04%. The authors missed no spine injuries in patients with head injuries. CONCLUSION: The use of the authors' protocol resulted in excellent sensitivity and specificity in detecting cervical spine injuries. In addition, it allowed early removal of spinal precautions.

Adolescent↗

PubMed2004

Immune evasion proteins of human cytomegalovirus do not prevent a diverse CD8+ cytotoxic T-cell response in natural infection.

Although cytomegalovirus (CMV) expresses proteins that interfere with antigen presentation by class I major histocompatibility complex (MHC) molecules, CD8+ cytotoxic T cells (CTLs) are indispensable for controlling infection and maintaining latency. Here, a cytokine flow cytometry assay that employs fibroblasts infected with a mutant strain of CMV (RV798), which is deleted of the 4 viral genes that are responsible for interfering with class I MHC presentation, was used to examine the frequency and specificity of the CD8+ CTLs to CMV in immunocompetent CMV-seropositive individuals. A large fraction of the CD8+ CTL response was found to be specific for viral antigens expressed during the immediate early and early phases of virus replication and presented by fibroblasts infected with RV798 but not wild-type CMV. These results demonstrate that the inhibition of class I antigen presentation observed in CMV-infected cells in vitro is not sufficient to prevent the induction of a broad repertoire of CD8+ CTLs after natural infection in vivo. Thus, reconstitution of T-cell immunity in immunodeficient patients by cell therapy or by vaccination may need to target multiple viral antigens to completely restore immunologic control of CMV.

Antigen Presentation↗

PubMed2003

Impaired killing of HCMV-infected retinal pigment epithelial cells by anti-pp65 CD8(+) cytotoxic T cells.

PURPOSE: Host defense against infection by human cytomegalovirus (HCMV) is ensured in great part by cytotoxic CD8(+) T lymphocytes (CTLs) directed against the tegument protein pp65. The hyperimmediate release of incoming pp65 into the major histocompatibility complex (MHC) class I pathway after fusion of the virus with the cell membrane provides a very early mechanism of defense. In retinal pigment epithelial (RPE) cells HCMV is known to enter through endocytosis. This study was conducted to determine whether this means of penetration into the cells would allow the virus to elude immune surveillance. METHODS: Infection of RPE cells with HCMV AD169 was performed for 6 hours, 48 hours, and 8 days. Expression of intracellular pp65 in RPE cells and in the astrocytoma reference cell line U373MG was evaluated by flow cytometry, fluorescence microscopy, and Western blot analysis. Killing of both HCMV-infected cell lines by HLA-A2-restricted CD8(+) CTLs directed against pp65 was monitored by (51)Cr-release assays. RESULTS: RPE cells were not lysed by CTLs directed against incoming pp65, contrary to U373MG. Moreover, both cell lines were not killed by anti-pp65 CTLs later after infection, because of the MHC class-I-downregulating effect of HCMV unique short (US2-11) proteins. CONCLUSIONS: In RPE cells, both HCMV entry through endocytosis and the immunosuppressive effect of US proteins could allow the virus to evade immune surveillance at any stage of infection, which could promote viral spreading within the retina.

Blotting, Western↗

PubMed2003

"Escape" velocity.

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Accidents, Aviation↗

PubMed2002

Association between immune recovery uveitis and a diverse intraocular cytomegalovirus-specific cytotoxic T cell response.

Cytomegalovirus (CMV) causes serious infection in individuals with deficient T cell immunity. In acquired immunodeficiency syndrome, the retina is a major site of progressive infection, despite the availability of therapy that targets CMV. The administration of highly active antiretroviral therapy to suppress human immunodeficiency virus frequently results in resolution of CMV retinitis, but this may be complicated by ocular inflammation termed "immune recovery uveitis" (IRU). To provide insight into the pathogenesis of IRU, the phenotype and specificity of intraocular T cells in a single patient were analyzed. The T cell infiltrate consisted of a diverse population of CD8(+) CMV-specific T cells, but only a minority of these T cells recognized the CMV phosphoprotein 65 and immediate early protein 1, which have been considered major targets of the host response. These results imply that reconstitution of CMV-specific T cells plays a role in IRU and suggest that the specificity of T cells engaged in the control of CMV at local sites of reactivation may be broad.

Cytomegalovirus↗

PubMedDate not supplied

Subareolar injection of 99mTc facilitates sentinel lymph node identification.

BACKGROUND: Sentinel lymph node (SLN) biopsy with the standard intraparenchymal injection has been accepted as an alternative to routine axillary dissection for patients with breast cancer. However, the identification and false-negative rates with this method can vary widely from surgeon to surgeon. The subareolar location contains a rich lymphatic network and represents a potential site of injection for SLN identification. METHODS: Between August 1, 1999, and December 31, 2000, we performed 159 SLN biopsy procedures on 158 patients with breast cancer. For each patient, 99mTc-labeled sulfur colloid was injected into the subareolar location, and 1% isosulfan blue dye was given as an intraparenchymal injection. RESULTS: In every case, at least one radioactive SLN was identified with the subareolar injection of technetium; a blue SLN was found in 97% of the cases. The blue SLN was also radioactive in 98% of the cases, indicating that the blue dye injected around the tumor and the technetium injected into the subareolar location drained to the same SLN. CONCLUSIONS: Subareolar injection of technetium can improve SLN identification rates for breast cancer. The simplicity and accuracy of this technique may also reduce the variable results reported with the standard intraparenchymal method.

Adult↗