9 resultados para Mild Head

em DigitalCommons@The Texas Medical Center


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Trauma and severe head injuries are important issues because they are prevalent, because they occur predominantly in the young, and because variations in clinical management may matter. Trauma is the leading cause of death for those under age 40. The focus of this head injury study is to determine if variations in time from the scene of accident to a trauma center hospital makes a difference in patient outcomes.^ A trauma registry is maintained in the Houston-Galveston area and includes all patients admitted to any one of three trauma center hospitals with mild or severe head injuries. A study cohort, derived from the Registry, includes 254 severe head injury cases, for 1980, with a Glasgow Coma Score of 8 or less.^ Multiple influences relate to patient outcomes from severe head injury. Two primary variables and four confounding variables are identified, including time to emergency room, time to intubation, patient age, severity of injury, type of injury and mode of transport to the emergency room. Regression analysis, analysis of variance, and chi-square analysis were the principal statistical methods utilized.^ Analysis indicates that within an urban setting, with a four-hour time span, variations in time to emergency room do not provide any strong influence or predictive value to patient outcome. However, data are suggestive that at longer time periods there is a negative influence on outcomes. Age is influential only when the older group (55-64) is included. Mode of transport (helicopter or ambulance) did not indicate any significant difference in outcome.^ In a multivariate regression model, outcomes are influenced primarily by severity of injury and age which explain 36% (R('2)) of variance. Inclusion of time to emergency room, time to intubation, transport mode and type injury add only 4% (R('2)) additional contribution to explaining variation in patient outcome.^ The research concludes that since the group most at risk to head trauma is the young adult male involved in automobile/motorcycle accidents, more may be gained by modifying driving habits and other preventive measures. Continuous clinical and evaluative research are required to provide updated clinical wisdom in patient management and trauma treatment protocols. A National Institute of Trauma may be required to develop a national public policy and evaluate the many medical, behavioral and social changes required to cope with the country's number 3 killer and the primary killer of young adults.^

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STATEMENT OF PROBLEM: Long-term fluoride application on the teeth of patients receiving radiation therapy for head and neck tumors results in excessive staining and roughening of ceramic restorations. PURPOSE: The purpose of this in vitro study was to compare the staining effects of 2 fluoride treatments on ceramic disks by simulating 1 year of clinical exposure at 10 minutes per day. In addition, 2 different surface preparations were tested. MATERIAL AND METHODS: Eighty ceramic disks (IPS Empress), 20 x 2 mm, were fabricated. Half of the disks were glazed, and the remaining disks were polished. All disks were brushed for 3 minutes with a soft-bristle power toothbrush and mild dentifrice (baseline) and were immersed in 1 of the 2 fluoride products (0.4% SnF(2), Gel-Kam Gel, or 1.1% NaF, Prevident 5000) for 10 days (n=20). Means and standard deviations of color change (Delta E), surface roughness (Ra, um), and surface gloss (GU) of the ceramic material were measured with a reflection spectrophotometer, a profilometer, and a gloss meter, respectively, at baseline and after fluoride treatment. Two- and 3-way ANOVA (alpha=.05), with surface preparation (polished vs. glazed) and fluoride treatment (0.4% SnF(2) or 1.1% NaF) as independent variables and condition (baseline vs. after fluoride treatment) as a repeated measure, was used to analyze the data. Fisher's PLSD intervals (alpha=.05) were calculated for comparisons among the means. RESULTS: The polished specimens had significantly higher Delta E values, significantly higher surface gloss values, and significantly lower surface roughness values than the glazed specimens before fluoride treatment (P<.001). After both fluoride treatments, ceramic disks exhibited significantly higher surface roughness values when polished and significantly lower surface gloss values when glazed or polished (P<.001). The glazed specimens presented significantly higher surface roughness (P<.001) and lower surface gloss values (P<.001) when treated with 0.4% SnF(2) as compared to NaF. For the polished specimens, there was no significant difference in surface roughness and surface gloss values between the 2 fluoride treatments. CONCLUSIONS: Use of 0.4% SnF(2) and 1.1% NaF gels, in vitro, caused significant color change in the polished IPS Empress ceramic disks. Polishing of the ceramic surface before immersion in either fluoride agent caused the ceramic tested to be more resistant to etching by the 2 solutions tested. The NaF caused less deterioration of the porcelain surface and was less stain inducing than SnF(2).

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We report a locally aggressive collagenous myofibroblastic neoplasm of the mandible in an 18-year-old male. Clinically, the lesion presented with rapid growth and irregular mandibular bone destruction. Grossly, the tumor was 10 cm in greatest dimension, light-tan, firm, and involving the posterior one-thirds of the body and inferior half of the left mandibular ramus. Histologically, the lesion was composed of a loose spindle cell proliferation interspersed with periodic dense bands of collagen. The spindle cells reacted positively to smooth muscle actin, calponin, and focally to desmin and were negative for S-100, pan-cytokeratin, CD99, CD34 and caldesmon, supporting myofibroblastic derivation. At our 4 year follow-up, the patient remained free of local recurrence and surgery related complications. The clinicopathologic findings and the differential diagnosis of this lesion is presented and discussed.

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Squamous cell carcinoma of head and neck (SCCHN) is the tenth most common cancer in the world. Unfortunately, the survival of patients with SCCHN has not improved in the last 40 years. Therefore new targets for therapy are needed, and to this end we are studying signaling pathways activated by IL-6 which we have found stimulates cell migration and soft agar growth in SCCHN. Our data show that IL-6 increases TWIST expression in a transcription-independent mechanism in many SCCHN cell lines. Further investigation reveals TWIST can be phosphorylated upon IL-6 treatment. By computation prediction (http://scansite.mit.edu/motifscan_seq.phtml ), we found that TWIST has a putative phosphorylation site for casein kinase 2 (CK2) suggesting that this kinase could serve as a link between IL-6 stimulation and Twist stability. To test this hypothesis, we used a CK2 inhibitor and shRNA to CK2 and found that these interventions inhibited IL-6 stimulation of TWIST stability. In addition, mutation of the putative CK2 phosphorylation site (S18/S20A) in TWIST decreased the amount of phospho-ATP incorporated by TWIST in an in vitro kinase assay, and altered TWIST stability. In Boyd chamber migration assay and wound-healing assay, the CK2 inhibitor, DMAT, was found to decrease the motility of IL-6 stimulated SCCHN cells and over expression of either a wild-type or the hyperphosphorylated mimicking mutant S18/20D –Twist rather than the hypo-phosphorylated mimicking mutant S18/20A-Twist can promote SCCHN cell motility.To our knowledge, this is the first report to identify the importance of IL-6 stimulated CK2 phosphorylation of TWIST in SCCHN. As CK2 inhibitors are currently under phase I clinical trials, our findings indicate that CK2 may be a viable therapeutic target in SCCHN. Therefore, further pre-clinical studies of this inhibitor are underway.

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Methylating agents are involved in carcinogenesis, and the DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT) removes methyl group from O(6)-methylguanine. Genetic variation in DNA repair genes has been shown to contribute to susceptibility to squamous cell carcinoma of the head and neck (SCCHN). We hypothesize that MGMT polymorphisms are associated with risk of SCCHN. In a hospital-based case-control study of 721 patients with SCCHN and 1234 cancer-free controls frequency-matched by age, sex and ethnicity, we genotyped four MGMT polymorphisms, two in exon 3, 16195C>T and 16286C>T and two in the promoter region, 45996G>T and 46346C>A. We found that none of these polymorphisms alone had a significant effect on risk of SCCHN. However, when these four polymorphisms were evaluated together by the number of putative risk genotypes (i.e. 16195CC, 16286CC, 45996GT+TT, and 46346CA+AA), a statistically significantly increased risk of SCCHN was associated with the combined genotypes with three to four risk genotypes, compared with those with zero to two risk genotypes (adjusted odds ratio (OR)=1.27; 95% confidence interval (CI)=1.05-1.53). This increased risk was also more pronounced among young subjects (OR=1.81; 95% CI=1.11-2.96), men (OR=1.24; 95% CI=1.00-1.55), ever smokers (OR=1.25; 95%=1.01-1.56), ever drinkers (OR=1.29; 95% CI=1.04-1.60), patients with oropharyngeal cancer (OR=1.45; 95% CI=1.12-1.87), and oropharyngeal cancer with regional lymph node metastasis (OR=1.52; 95% CI=1.16-1.89). In conclusion, our results suggest that any one of MGMT variants may not have a substantial effect on SCCHN risk, but a joint effect of several MGMT variants may contribute to risk and progression of SCCHN, particularly for oropharyngeal cancer, in non-Hispanic whites.

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Purpose: First, to determine an average and maximum displacement of the shoulder relative to isocenter over the course of treatment. Second, to establish the dosimetric effect of shoulder displacements relative to correct isocenter alignment on the dose delivered to the target and the surrounding structures for head and neck cancer patients. Method and Materials: The frequency of shoulder shifts of various magnitudes relative to isocenter was assessed for 4 patients using image registration software. The location of the center of the right and left humeral head relative to isocenter (usually C2) was found daily from CT on rails scans, and was compared to the location of the humeral heads relative to isocenter on the initial simulation CT. Three Baseline head and neck IMRT and SmartArc plans were generated in Pinnacle based on simulation CTs. The CT datasets (external contour and boney structures) were then modified to represent shifts of the shoulder (relative to isocenter) between 3 mm and 15 mm in the SI, AP, and LR directions. The initial plans were recalculated on the image sets with shifted shoulders. Results: On average, shoulder variation was 2-5 mm in each direction, although displacements of over 1 cm in the inferior and posterior directions occurred. Shoulder shifts induced perturbations in the dose distribution, although generally only for large shifts. Most substantially, large, superior shifts resulted in coverage loss by the 95% isodose line for targets in the lower neck. Inferior shifts elevated the dose to the brachial plexus by 0.6-4.1 Gy. SmartArc plans showed similar loss of target coverage as IMRT plans. Conclusions: The position of the shoulder can have an impact on target coverage and critical structure dose. Shoulder position may need to be considered for setup of head and neck patients depending on target location.

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Proton therapy has become an increasingly more common method of radiation therapy, with the dose sparing to distal tissue making it an appealing option, particularly for treatment of brain tumors. This study sought to develop a head phantom for the Radiological Physics Center (RPC), the first to be used for credentialing of institutions wishing to participate in clinical trials involving brain tumor treatment of proton therapy. It was hypothesized that a head phantom could be created for the evaluation of proton therapy treatment procedures (treatment simulation, planning, and delivery) to assure agreement between the measured dose and calculated dose within ±5%/3mm with a reproducibility of ±3%. The relative stopping power (RSP) and Hounsfield Units (HU) were measured for potential phantom materials and a human skull was cast in tissue-equivalent Alderson material (RLSP 1.00, HU 16) with anatomical airways and a cylindrical hole for imaging and dosimetry inserts drilled into the phantom material. Two treatment plans, proton passive scattering and proton spot scanning, were created. Thermoluminescent dosimeters (TLDs) and film were loaded into the phantom dosimetry insert. Each treatment plan was delivered three separate times. Each treatment plan passed our 5%/3mm criteria, with a reproducibility of ±3%. The hypothesis was accepted and the phantom was found to be suitable for remote audits of proton therapy treatment facilities.

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Currently, there are no molecular biomarkers that guide treatment decisions for patients with head and neck squamous cell carcinoma (HNSCC). Several retrospective studies have evaluated TP53 in HNSCC, and results have suggested that specific mutations are associated with poor outcome. However, there exists heterogeneity among these studies in the site and stage of disease of the patients reviewed, the treatments rendered, and methods of evaluating TP53 mutation. Thus, it remains unclear as to which patients and in which clinical settings TP53 mutation is most useful in predicting treatment failure. In the current study, we reviewed the records of a cohort of patients with advanced, resectable HNSCC who received surgery and post-operative radiation (PORT) and had DNA isolated from fresh tumor tissue obtained at the time of surgery. TP53 mutations were identified using Sanger sequencing of exons 2-11 and the associated splice regions of the TP53 gene. We have found that the group of patients with either non-disruptive or disruptive TP53 mutations had decreased overall survival, disease-free survival, and an increased rate of distant metastasis. When examined as an independent factor, disruptive mutation was strongly associated with the development of distant metastasis. As a second aim of this project, we performed a pilot study examining the utility of the AmpliChip® p53 test as a practical method for TP53 sequencing in the clinical setting. AmpliChip® testing and Sanger sequencing was performed on a separate cohort of patients with HNSCC. Our study demonstrated the ablity of the AmpliChip® to call TP53 mutation from a single formalin-fixed paraffin-embedded slide. The results from AmpliChip® testing were identical with the Sanger method in 11 of 19 cases, with a higher rate of mutation calls using the AmpliChip® test. TP53 mutation is a potential prognostic biomarker among patients with advanced, resectable HNSCC treated with surgery and PORT. Whether this subgroup of patients could benefit from the addition of concurrent or induction chemotherapy remains to be evaluated in prospective clinical trials. Our pilot study of the p53 AmpliChip® suggests this could be a practical and reliable method of TP53 analysis in the clinical setting.

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Patients with head and neck squamous cell carcinoma (HNSCC) demonstrate abnormal cell-mediated immunity which is most pronounced at the primary tumor site. Therefore, we tested whether this aberrant immunity could be due to tumor-derived cytokines. We investigated the presence of cytokine mRNA and protein in 8 HNSCC-derived cell lines; RT-PCR results indicated mRNA's for IL-1$\alpha$ and TGF-$\alpha$ (8/8), TGF-$\beta$ (7/8), IL-1$\beta$ (7/8), IL-4 and IL-6 (4/8). IL-2, IFN-$\gamma,$ and TNF-$\alpha$ mRNA was not detected. Supernatants from 6 of these cell lines were analyzed by ELISA and IL-1$\alpha,$ IL-1$\beta,$ and IL-6 were markedly increased compared to HPV-16 immortalized human oral keratinocytes. IL-1$\alpha$ was found in the highest concentration $>$IL-6 $>$ IL-1$\beta.$^ To approach the mechanisms of cytokine regulation, 4 cell lines were compared for HPV DNA presence, p53 status, and cytokine expression. An association between HPV DNA and cytokine expression was not found. However, cell lines secreting the most IL-6 had mutant p53 and/or HPV 16 E6/E7 expression. Further regulatory investigations revealed that exogenous IL-1$\alpha$ and/or IL-1$\beta$ minimally stimulated the proliferation of 2/3 cell lines, as well as strongly induced IL-6 production in 3/3; this effect was completely abrogated by IL-1Ra. IL-1Ra also inhibited the secretion of IL-1$\alpha$ and IL-1$\beta$ in 2/3 cell lines. These data suggest an IL-1 autocrine loop in certain HNSCC cell lines. Because IL-2 induces IL-1 and is used in therapy of HNSCC, the expression of IL-2 receptor was also investigated; IL-2 $\alpha$ and $\beta$ subunits were detected in 3/3 cell lines and $\gamma$ subunits was detected in one. Exogenous IL-2 inhibited the proliferation, but stimulated the secretion of IL-1$\alpha$ in 2/3, and IL-1$\beta$ and IL-6 in 1/3 cell lines.^ To determine if our cell line findings were applicable to patients, immunohistochemistry was performed on biopsies from 12 invasive tumors. Unexpectedly, universal intracellular production of IL-1$\alpha,$ IL-1$\beta,$ and IL-6 protein was detected. Therefore, the aberrant elaboration of biologically active IL-1 and IL-6 may contribute to altered immune status in HNSCC patients. ^