269 research outputs found

    Extraforaminal ligament attachments of the thoracic spinal nerves in humans

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    An anatomical study of the extraforaminal attachments of the thoracic spinal nerves was performed using human spinal columns. The objectives of the study are to identify and describe the existence of ligamentous structures at each thoracic level that attach spinal nerves to structures at the extraforaminal region. During the last 120 years, several mechanisms have been described to protect the spinal nerve against traction. All the described structures were located inside the spinal canal proximal to the intervertebral foramen. Ligaments with a comparable function just outside the intervertebral foramen are mentioned ephemerally. No studies are available about ligamentous attachments of thoracic spinal nerves to the spine. Five embalmed human thoracic spines (Th2–Th11) were dissected. Bilaterally, the extraforaminal region was dissected to describe and measure anatomical structures and their relationships with the thoracic spinal nerves. Histology was done at the sites of attachment of the ligaments to the nerves and along the ligaments. The thoracic spinal nerves are attached to the transverse process of the vertebrae cranial and caudal to the intervertebral foramen. The ligaments consist mainly of collagenous fibers. In conclusion, at the thoracic level, direct ligamentous connections exist between extraforaminal thoracic spinal nerves and nearby structures. They may serve as a protective mechanism against traction and compression of the nerves by positioning the nerve in the intervertebral foramen

    Panorametry: suggestion of a method for mandibular measurements on panoramic radiographs

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    <p>Abstract</p> <p>Background</p> <p>Orthopantomography (panoramic radiography) has been used for the study of measurements involving particularly the prediction of the eruption of impacted lower third molars and analyses of measurements of the ramus and head of mandible. The discrepancies involved with the projection of this radiographic image has stimulated the search for further ways to use it, particularly in orthodontic treatments and oral and maxillofacial surgeries. The author proposes a graphimetric method for the mandible, based on panoramic radiography. The results are expressed in linear and angular measurements, aiming at bilateral comparisons as well as the determination of the proportion of skeletal and dental structures, individually and among themselves as a whole. The method has been named Panorametry, and allows measurement of the mandible (Mandibular Panorametry) or the posterior mandibular teeth (Dental Panorametry). When combining mandible and maxilla, it should be referred to as Total Panorametry. It may also be used, in the future, with Cone Beam computed tomography (CT) images, and in this case it may be mentioned as CT Panorametry.</p

    A phase I/II study of oxaliplatin when added to 5-fluorouracil and leucovorin and pelvic radiation in locally advanced rectal cancer: a Colorectal Clinical Oncology Group (CCOG) study

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    The purpose of this study was to evaluate the maximum tolerated dose (MTD) and recommended dose of oxaliplatin given synchronously with 5-fluorouracil (5FU), leucovorin (LV) and preoperative pelvic radiation for primary unresectable, locally advanced, rectal cancer. Preoperative pelvic radiotherapy using a three- or four-field technique and megavoltage photons comprised 45 Gy given in 25 fractions, 1.8 Gy per fraction, and delivered with escalating doses of oxaliplatin in combination with low-dose LV and 5FU. Chemotherapy was given synchronously with radiotherapy in weeks 1 and 5. Escalating doses of oxaliplatin (85, 130 and 150 mg m−2) were given on days 2 and 30, followed by low-dose LV (20 mg m−2) and 5FU (350 mg m−2), both given on days 1–5 and 29–33. Surgery was performed 6–10 weeks later. The MTD was determined as the dose causing more than a third of patients to have a dose-limiting toxicity (DLT). Once the MTD was reached, a further 14 patients were treated at the dose level below the MTD. In all, 32 patients received oxaliplatin at the three dose levels, median age 60 years (range 31–79), 24 males and eight females. The MTD was reached at 150 mg m−2 when four out of six patients experienced DLT. Dose-limiting grade 3 or 4 diarrhoea was reported in two out of six patients at 85 mg m−2, 5 out of 20 at 130 mg m−2 and four out of 6 at 150 mg m−2. Grade 3 neuropathy was reported at 130 mg m−2 (1 out of 20) and at 150 mg m−2 (two out of six), and serious haematological toxicity was minimal; one grade 3 anaemia at 150 mg m−2. In all, 28 out of 32 patients completed all treatments as planned; three had radiotherapy interrupted and three a chemotherapy dose reduction. Four patients did not proceed to surgery due to the presence of metastatic disease (two), unfitness (one) or patient refusal (one). Also, 28 patients underwent surgical resection. Histopathology demonstrated histopathological complete response (pCR) 2 out of 27 (7%), Tmic 3 out of 27 (11%), pCR+Tmic 5 out of 27 (19%), pT0–2 6 out of 27 (22%) and histologically confirmed clear circumferential resection margins in 22 out of 27 (81%). Dose-limiting toxicity with oxaliplatin is 150 mg m−2 given days 2 and 30 when added to the described 5FU LV and 45 Gy radiation preoperatively. The acceptable toxicity and compliance at 130 mg m−2 recommend testing this dose in future phase II studies. The tumour downstaging and complete resection rates are encouragingly high for this very locally advanced group

    Concurrent chemoradiation with capecitabine and weekly irinotecan as preoperative treatment for rectal cancer: results from a phase I/II study

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    The aim of this study was to investigate the efficacy and safety of chemoradiation using capecitabine and irinotecan as neoadjuvant therapy for patients with rectal cancer. Conventional radiation was given at daily fractions of 1.8 Gy on 5 days a week for a total dose of 55.8 (50.4+5.4) Gy. Concurrently, irinotecan 40 mg m−2 once weekly and capecitabine continuously at dose levels of 500, 650, 750 and 825 mg m−2 twice daily were administered. Surgery was performed 4–6 weeks following completion of chemoradiation. A total of 28 patients (3 UICC II, 25 UICC III) were enrolled and all received treatment. Dose-limiting toxicity was diarrhoea grade IV and hand–foot syndrome at the 825 mg m−2 dose level. The maximum tolerated dose of capecitabine was 750 mg m−2. Diarrhoea was the most common toxicity: grade III in nine patients. Two patients died, one due to pneumonia and one due to sudden cardiac death. A complete response and only microfocal residual tumour disease was achieved in four and three patients (27%). In all, 25 of 28 patients undergoing surgery, 24 (96%) had R0 resection. Preoperative chemoradiation based on continuous daily capecitabine and weekly irinotecan appears to tolerated and effective in patients with rectal cancer

    Monoclonal antibody A7-superparamagnetic iron oxide as contrast agent of MR imaging of rectal carcinoma

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    Superparamagnetic iron oxide (SPIO)-based colloid has been used clinically as a tissue-specific magnetic resonance contrast agent. We coupled monoclonal antibody A7 (Mab A7), which reacts specifically with human colorectal carcinoma, to Ferumoxides (SPIO) and examined the accumulation of this conjugate in xenografted tumours in nude mice. We examined in vitro immunoreactivity of Mab A7 coupled to Ferumoxides and its in vivo distribution in nude mice with human colorectal carcinoma. Magnetic resonance imaging of tumour-bearing nude mice was performed 72 h after injection of A7-Ferumoxides. A7-Ferumoxides retained binding activities that were nearly identical to intact Mab A7. More of the radiolabelled A7-Ferumoxides accumulated in the tumour than normal mouse IgG-Ferumoxides from 12 h onwards after injection (P<0.05). Both A7-Ferumoxides and normal mouse IgG-Ferumoxides disappeared from blood linearly over time. The accumulation levels in normal tissue decreased linearly over time but were lower than levels in tumours from 6 h. In magnetic resonance T2-weighted imaging of the tumour-bearing nude mice, signal intensity was reduced at the margin of the tumour by injection of A7-Ferumoxides. Mab A7 coupled to Ferumoxides is potentially suitable as a magnetic resonance contrast agent for detecting local recurrence of rectal carcinoma

    Effectiveness of preoperative staging in rectal cancer: digital rectal examination, endoluminal ultrasound or magnetic resonance imaging?

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    In rectal cancer, preoperative staging should identify early tumours suitable for treatment by surgery alone and locally advanced tumours that require therapy to induce tumour regression from the potential resection margin. Currently, local staging can be performed by digital rectal examination (DRE), endoluminal ultrasound (EUS) or magnetic resonance imaging (MRI). Each staging method was compared for clinical benefit and cost-effectiveness. The accuracy of high-resolution MRI, DRE and EUS in identifying favourable, unfavourable and locally advanced rectal carcinomas in 98 patients undergoing total mesorectal excision was compared prospectively against the resection specimen pathological as the gold standard. Agreement between each staging modality with pathology assessment of tumour favourability was calculated with the chance-corrected agreement given as the kappa statistic, based on marginal homogenised data. Differences in effectiveness of the staging modalities were compared with differences in costs of the staging modalities to generate cost effectiveness ratios. Agreement between staging and histologic assessment of tumour favourability was 94% for MRI (kappa=0.81, s.e.=0.05; kappa(W)=0.83), compared with very poor agreements of 65% for DRE (kappa=0.08, s.e.=0.068, kappa(W)=0.16) and 69% for EUS (kappa=0.17, s.e.=0.065, kappa(W)=0.17). The resource benefits resulting from the use of MRI rather than DRE was 67164 UK pounds and 92244 UK pounds when MRI was used rather than EUS. Magnetic resonance imaging dominated both DRE and EUS on cost and clinical effectiveness by selecting appropriate patients for neoadjuvant therapy and justifies its use for local staging of rectal cancer patients

    Bromodeoxyuridine Labeling Index as an Indicator of Early Tumor Response to Preoperative Radiotherapy in Patients with Rectal Cancer

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    PURPOSE: Assessment of tumor proliferation rate using Bromodeoxyuridine labeling index (BrdUrdLI) as a possible predictor of rectal cancer response to preoperative radiotherapy (RT). METHODS AND MATERIAL: Ninety-two patients were qualified either to short RT (5 Gy/fraction/5 days) and surgery about 1 week after RT (schedule I), or to short RT and 4–5 weeks interval before surgery (schedule II). Tumor samples were taken twice from each patient: before RT and at the time of surgery. The samples were incubated with BrdUrd for 1 h at 37°C, and the BrdUrdLI was calculated as a percentage of BrdUrd-labeled cells. RESULTS: Thirty-eight patients were treated according to schedule I and 54 patients according to schedule II. Mean BrdUrdLI before RT was 8.5% and its value did not differ between the patients in the two compared groups. After RT tumors showed statistically significant growth inhibition (reduction of BrdUrdLI). As the pretreatment BrdUrd LI was not predictive for early clinical and pathologic tumor response, prognostic role of the ratio of BrdUrdLI after to BrdUrdLI before RT was considered. The ratios were calculated separately for fast (BrdUrd LI > 8.5%) and slowly (BrdUrd LI ≤ 8.5%) proliferating tumors and correlated with overall treatment time (OTT, i.e., time from the first day of RT to surgery). One month after RT, accelerated proliferation was observed only in slowly proliferating tumors. CONCLUSIONS: Pretreatment BrdUrdLI was not predictive for early clinical and pathologic tumor response. The ratio after/before RT BrdUrdLI was correlated to inhibition of proliferation in responsive tumors

    Analyses of cerebral microdialysis in patients with traumatic brain injury: relations to intracranial pressure, cerebral perfusion pressure and catheter placement

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    <p>Abstract</p> <p>Background</p> <p>Cerebral microdialysis (MD) is used to monitor local brain chemistry of patients with traumatic brain injury (TBI). Despite an extensive literature on cerebral MD in the clinical setting, it remains unclear how individual levels of real-time MD data are to be interpreted. Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) are important continuous brain monitors in neurointensive care. They are used as surrogate monitors of cerebral blood flow and have an established relation to outcome. The purpose of this study was to investigate the relations between MD parameters and ICP and/or CPP in patients with TBI.</p> <p>Methods</p> <p>Cerebral MD, ICP and CPP were monitored in 90 patients with TBI. Data were extensively analyzed, using over 7,350 samples of complete (hourly) MD data sets (glucose, lactate, pyruvate and glycerol) to seek representations of ICP, CPP and MD that were best correlated. MD catheter positions were located on computed tomography scans as pericontusional or nonpericontusional. MD markers were analyzed for correlations to ICP and CPP using time series regression analysis, mixed effects models and nonlinear (artificial neural networks) computer-based pattern recognition methods.</p> <p>Results</p> <p>Despite much data indicating highly perturbed metabolism, MD shows weak correlations to ICP and CPP. In contrast, the autocorrelation of MD is high for all markers, even at up to 30 future hours. Consequently, subject identity alone explains 52% to 75% of MD marker variance. This indicates that the dominant metabolic processes monitored with MD are long-term, spanning days or longer. In comparison, short-term (differenced or Δ) changes of MD vs. CPP are significantly correlated in pericontusional locations, but with less than 1% explained variance. Moreover, CPP and ICP were significantly related to outcome based on Glasgow Outcome Scale scores, while no significant relations were found between outcome and MD.</p> <p>Conclusions</p> <p>The multitude of highly perturbed local chemistry seen with MD in patients with TBI predominately represents long-term metabolic patterns and is weakly correlated to ICP and CPP. This suggests that disturbances other than pressure and/or flow have a dominant influence on MD levels in patients with TBI.</p

    Irinotecan+5-fluorouracil with concomitant pre-operative radiotherapy in locally advanced non-resectable rectal cancer: a phase I/II study

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    In the UK, 10% of patients diagnosed with rectal cancer have inoperable disease at presentation. This study ascertained whether the resectability rate of inoperable locally advanced rectal cancer was improved by administration of intravenous irinotecan, 5-fluorouracil (5-FU) and pelvic radiotherapy. During phase I of the trial (n=12), the dose of irinotecan was escalated in three-patient cohorts from 50 mg m−2 to 60 mg m−2 to 70 mg m−2 to identify the maximum tolerated dose (60 mg m−2). In phase II, 31 patients with non-resectable disease received 45 Gy radiotherapy and 5-FU infusions (200 mg m−2 per day) for 5 weeks. Irinotecan (60 mg m−2) was given on days 1, 8, 15 and 22. After treatment, patients were operated on if possible. Thirty patients completed the protocol, 28 underwent surgery. Before surgery, MRI restaging of 24 patients showed that 19 (79%) had a reduction in tumour stage after treatment (seven complete clinical response and 12 partial). Of 27 patients followed up after surgery, 22 (81%) had clear circumferential resection margins. Disease-free and overall survival estimates at 3 years were 65 and 90%, respectively. The regimen was well tolerated. Irinotecan, 5-FU and radiotherapy results in tumour downgrading, allowing resection of previously inoperable tumour with acceptable toxicity

    The use of preoperative radiotherapy in the management of patients with clinically resectable rectal cancer: a practice guideline

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    BACKGROUND: This systematic review with meta-analysis was designed to evaluate the literature and to develop recommendations regarding the use of preoperative radiotherapy in the management of patients with resectable rectal cancer. METHODS: The MEDLINE, CANCERLIT and Cochrane Library databases, and abstracts published in the annual proceedings of the American Society of Clinical Oncology and the American Society for Therapeutic Radiology and Oncology were systematically searched for evidence. Relevant reports were reviewed by four members of the Gastrointestinal Cancer Disease Site Group and the references from these reports were searched for additional trials. External review by Ontario practitioners was obtained through a mailed survey. Final approval of the practice guideline report was obtained from the Practice Guidelines Coordinating Committee. RESULTS: Two meta-analyses of preoperative radiotherapy versus surgery alone, nineteen trials that compared preoperative radiotherapy plus surgery to surgery alone, and five trials that compared preoperative radiotherapy to alternative treatments were obtained. Randomized trials demonstrate that preoperative radiotherapy followed by surgery is significantly more effective than surgery alone in preventing local recurrence in patients with resectable rectal cancer and it may also improve survival. A single trial, using surgery with total mesorectal excision, has shown similar benefits in local recurrence. CONCLUSION: For adult patients with clinically resectable rectal cancer we conclude that: • Preoperative radiotherapy is an acceptable alternative to the previous practice of postoperative radiotherapy for patients with stage II and III resectable rectal cancer; • Both preoperative and postoperative radiotherapy decrease local recurrence but neither improves survival as much as postoperative radiotherapy combined with chemotherapy. Therefore, if preoperative radiotherapy is used, chemotherapy should be added postoperatively to at least patients with stage III disease
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