Interval between surgery and neoadjuvant chemoradiation therapy for distal rectal cancer: Does delayed surgery have an impact on outcome?

Background: The optimal interval between neoadjuvant chemoradiation therapy (CRT) and surgery in the treatment of patients with distal rectal cancer is controversial. The purpose of this study is to evaluate whether this interval has an impact on survival. Methods and Materials: Patients who underwent surgery after CRT were retrospectively reviewed. Patients with a sustained complete clinical response (cCR) 1 year after CRT were excluded from this study. Clinical and pathologic characteristics and overall and disease-free survival were compared between patients undergoing surgery 12 weeks or less from CRT and patients undergoing surgery longer than 12 weeks from CRT completion and between patients with a surgery delay caused by a suspected cCR and those with a delay for other reasons. Results: Two hundred fifty patients underwent surgery, and 48.4% had CRT-to-surgery intervals of 12 weeks or less. There were no statistical differences in overall survival (86% vs. 81.6%) or disease-free survival rates (56.5% and 58.9%) between patients according to interval (<= 12 vs. >1 2 weeks). Patients with intervals of 12 weeks or less had significantly higher rates of Stage III disease (34% vs. 20%; p = 0.009). The delay in surgery was caused by a suspected cCR in 23 patients (interval, 48 +/- 10.3 weeks). Five-year overall and disease-free survival rates for this subset were 84.9% and 51.6%, not significantly different compared with the remaining group (84%; p = 0.96 and 57.8 %; p = 0.76, respectively). Conclusions: Delay in surgery for the evaluation of tumor response after neoadjuvant CRT is safe and does not negatively affect survival. These results support the hypothesis that shorter intervals may interrupt ongoing tumor necrosis. (C) 2008 Elsevier Inc.

Influence of Cavity Preparation with Er:YAG Laser on Enamel Adjacent to Restorations Submitted to Cariogenic Challenge In Situ: A Polarized Light Microscopic Analysis

Background and Objectives: Er:YAG laser has been used for caries removal and cavity preparation, using ablative parameters. Its effect on the margins of restorations submitted to cariogenic challenge has not yet been sufficiently investigated. The aim of this study was to assess the enamel adjacent to restored Er:YAG laser-prepared cavities submitted to cariogenic challenge in situ, under polarized light microscopy. Study Design/Materials and Methods: Ninety-one enamel slabs were randomly assigned to seven groups (n = 13): I, II, III-Er:YAG laser with 250 mJ, 62.5 J/cm(2), combined with 2, 3, and 4 Hz, respectively; IV, V, VI-Er:YAG laser with 350 mJ, 87.5 J/cm(2), combined with 2, 3, and 4 Hz, respectively; VII-High-speed handpiece (control). Cavities were restored and the restorations were polished. The slabs were fixed to intra-oral appliances, worn by 13 volunteers for 14 days. Sucrose solution was applied to each slab six times per day. Samples were removed, cleaned, sectioned and ground to polarized light microscopic analysis. Demineralized area and inhibition zone width were quantitatively assessed. Presence or absence of cracks was also analyzed. Scores for demineralization and inhibition zone were determined. Results: No difference was found among the groups with regard to demineralized area, inhibition zone width, presence or absence of cracks, and demineralization score. Inhibition zone score showed difference among the groups. There was a correlation between the quantitative measures and the scores. Conclusion: Er:YAG laser was similar to high-speed handpiece, with regard to alterations in enamel adjacent to restorations submitted to cariogenic challenge in situ. The inhibition zone score might suggest less demineralization at the restoration margin of the irradiated substrates. Correlation between the quantitative measures and scores indicates that score was, in this case, a suitable complementary method for assessment of caries lesion around restorations, under polarized light microscopy. Lasers Surg. Med. 40:634-643, 2008. (c) 2008 Wiley-Liss, Inc.

Adhesive Temperature: Effects on Adhesive Properties and Resin-Dentin Bond Strength

Objectives: To evaluate the effect of adhesive temperature on the resin-dentin bond strength (mu TBS), nanoleakage (NL), adhesive layer thickness (AL), and degree of conversion (DC) of ethanol/water- (SB) and acetone-based (PB) etch-and-rinse adhesive systems. Methods: The bottles of the two adhesives were kept at each temperature (5 degrees C, 20 degrees C, 37 degrees C, and 50 degrees C) for 2 hours before application to demineralized dentin surfaces of 40 molars. Specimens were prepared for mu TBS testing. Bonded sticks (0.8 mm(2)) were tested under tension (0.5 mm/min). Three bonded sticks from each tooth were immersed in silver nitrate and analyzed by scanning electron microscopy. The DC of the adhesives was evaluated by Fourier transformed infrared spectroscopy. Results: Lower mu TBS was observed for PB at 50 degrees C. For SB, the mu TBS values were similar for all temperatures. DC was higher at 50 degrees C for PB. Higher NL and thicker AL were observed for both adhesives in the 5 degrees C and 20 degrees C groups compared to the 37 degrees C and 50 degrees C groups. The higher temperatures (37 degrees C or 50 degrees C) reduced the number of pores within the adhesive layer of both adhesive systems. Conclusions: It could be useful to use an ethanol/water-based adhesive at 37 degrees C or 50 degrees C and an acetone-based adhesive at 37 degrees C to improve adhesive performance.

Standardised audit of hip fractures in Europe

The objectives of this study were to evaluate the outcomes of our patients admitted with hip fractures, and to benchmark these results with other hospitals, initially in Europe and subsequently in Australia. The Standardised Audit of Hip Fractures in Europe (SAHFE) questionnaires was used as the data gathering instrument. The participants were all patients admitted to Redcliffe Hospital with a fractured neck of femur prior to surgery. This paper reports the results of the first 70 consecutive patients admitted to Redcliffe Hospital with a fractured neck of femur from November 1st 2000. The main outcome measures were mobility, independence, residence prior to fracture; type of fracture and surgical repair; and time to surgery, survival rates and discharge destination. Results: 43 patients were admitted from home, but only 13 returned home directly from the orthopaedic ward. It is hoped that most of the 26 transferred to the rehabilitation ward will ultimately return home. 7 patients died, these were aged 82 to 102, and all had premorbid disease. Delays in surgery were apparent for 13 patients, mainly due to administrative problems. Conclusions: We support the recommendation in the Fifteenth Scottish Intercollegiate Guidelines Network Publication on the management of hip fractures, that all units treating this condition should enter an audit to evaluate their management. (author abstract)

Fracture toughness determination of adhesive and co-cured joints in natural fibre composites

Adhesive bonding has become more efficient in the last few decades due to the adhesives developments, granting higher strength and ductility. On the other hand, natural fibre composites have recently gained interest due to the low cost and density. It is therefore essential to predict the fracture behavior of joints between these materials, to assess the feasibility of joining or repairing with adhesives. In this work, the tensile fracture toughness (Gc n) of adhesive joints between natural fibre composites is studied, by bonding with a ductile adhesive and co-curing. Conventional methods to obtain Gc n are used for the co-cured specimens, while for the adhesive within the bonded joint, the J-integral is considered. For the J-integral calculation, an optical measurement method is developed for the evaluation of the crack tip opening and adherends rotation at the crack tip during the test, supported by a Matlab sub-routine for the automated extraction of these quantities. As output of this work, an optical method that allows an easier and quicker extraction of the parameters to obtain Gc n than the available methods is proposed (by the J-integral technique), and the fracture behaviour in tension of bonded and co-cured joints in jute-reinforced natural fibre composites is also provided for the subsequent strength prediction. Additionally, for the adhesively- bonded joints, the tensile cohesive law of the adhesive is derived by the direct method.

Structural adhesives modified with thermally expandable particles

In this study, the behaviour of two structural adhesives modified with thermally expandable particles (TEPs) was investigated as a preliminary study for further investigations on the potential of TEPs in adhesive joints. Tensile bulk tests were performed to get the tensile properties of the adhesives and TEPs-modified adhesives. In order to determine the expansion temperature of the particles while encapsulated in these particular adhesive systems, the variation of the volume of adhesive samples modified with different TEPs concentration as a function of temperature was measured. Further, the possibility of any chemical interactions between TEPs and adhesives matrix in the TEPs-modified specimens was verified by a Fourier transform infrared spectroscopy analysis. Finally, the fracture surfaces of the unmodified and TEPs-modified specimens, as well as the dispersion and the morphology of the particles, were examined by a scanning electron microscopy analysis. It was found that the stiffness of the TEPs-modified adhesives is not affected by incorporation of TEPs in the adhesives matrix, while the tensile yield strength decreased by increasing the wt% TEPs content. In applications of such particular materials (TEPs-modified adhesives), the temperature should be controlled to stay between 90°C and 120°C in order to obtain the highest expansion ratio. At a lower temperature, not all the particles will expand, and above, the TEPs will deteriorate and as a result the TEPs-modified adhesives will deteriorate.

N170 Asymmetry as an Index of Inferior Occipital Dysfunction in Patients With Symptomatic Occipital Lobe Epilepsy

Objective: Localizing epileptic foci in posterior brain epilepsy remains a difficult exercise in surgery for epilepsy evaluation. Neither clinical manifestations, neurological, EEG nor neuropsychological evaluations provide strong information about the area of onset, and fast spread of paroxysms often produces mixed features of occipital, temporal and parietal symptoms. We investigated the usefulness of the N170 event-related potential to map epileptic activity in these patients. Methods: A group of seven patients with symptomatic posterior cortex epilepsy were submitted to a high-resolution EEG (78 electrodes), with recordings of interictal spikes and face-evoked N170. Generators of spikes and N170 were localized by source analysis. Range of normal N170 asymmetry was determined in 30 healthy volunteers. Results: In 3 out of 7 patients the N170 inter-hemispheric asymmetry was outside control values. Those were the patients whose spike sources were nearest (within 3 cm) to the fusiform gyrus, while foci further away did not affect the N170 ratio. Conclusions: N170 event-related potential provides useful information about focal cortical dysfunction produced by epileptic foci located in the close neighborhood of the fusiform gyrus, but are unaffected by foci further away. Significance: The N170 evoked by faces can improve the epileptic foci localization in posterior brain epilepsy.

Surgical site infections in women and their association with clinical conditions

Introduction Surgical site infections (SSIs) can affect body tissues, cavities, or organs manipulated in surgery and constitute 14% to 16% of all infections. This study aimed to determine the incidence of SSIs in women following their discharge from a gynecology outpatient clinic, to survey different types of SSIs among women, and to verify the association of SSIs with comorbidities and clinical conditions. Methods Data were collected via analytical observation with a cross-sectional design, and the study was conducted in 1,026 women who underwent gynecological surgery in a teaching hospital in the municipality of Teresina, in the northeast Brazilian State of Piauí, from June 2011 to March 2013. Results The incidence of SSIs after discharge was 5.8% among the women in the outpatient clinic. The most prevalent surgery among the patients was hysterectomy, while the most prevalent type of SSI was superficial incisional. Comorbidities in women with SSIs included cancer, diabetes mellitus, and hypertension. Conclusions Surveillance of SSIs during the post-discharge period is critical for infection prevention and control. It is worth reflecting on the planning of surgical procedures for patients who have risk factors for the development of SSIs.

Gas emission during laparoscopic colorectal surgery using a bipolar vessel sealing device: A pilot study on four patients.

BACKGROUND: Dissection during laparoscopic surgery produces smoke containing potentially toxic substances. The aim of the present study was to analyze smoke samples produced during laparoscopic colon surgery using a bipolar vessel sealing device (LigaSuretrade mark). METHODS: Four consecutive patients undergoing left-sided colectomy were enrolled in this pilot study. Smoke was produced by the use of LigaSuretrade mark. Samples (5,5l) were evacuated from the pneumoperitoneum in a closed system into a reservoir. Analysis was performed with CO2-laser-based photoacoustic spectroscopy and confirmed by a Fourier-transform infrared spectrum. The detected spectra were compared to the available spectra of known toxins. RESULTS: Samples from four laparoscopic sigmoid resections were analyzed. No relevant differences were noted regarding patient and operation characteristics. The gas samples were stable over time proven by congruent control measurements as late as 24 h after sampling. The absorption spectra differed considerably between the patients. One broad absorption line at 100 ppm indicating H2O and several unknown molecules were detected. With a sensitivity of alpha min ca 10-5 cm-1 no known toxic substances like phenol or indole were identified. CONCLUSION: The use of a vessel sealing device during laparoscopic surgery does not produce known toxic substances in relevant quantity. Further studies are needed to identify unknown molecules and to analyze gas emission under various conditions.

Variability of indication criteria in knee and hip replacement: an observational study

BACKGROUND. Total knee (TKR) and hip (THR) replacement (arthroplasty) are effective surgical procedures that relieve pain, improve patients' quality of life and increase functional capacity. Studies on variations in medical practice usually place the indications for performing these procedures to be highly variable, because surgeons appear to follow different criteria when recommending surgery in patients with different severity levels. We therefore proposed a study to evaluate inter-hospital variability in arthroplasty indication. METHODS. The pre-surgical condition of 1603 patients included was compared by their personal characteristics, clinical situation and self-perceived health status. Patients were asked to complete two health-related quality of life questionnaires: the generic SF-12 (Short Form) and the specific WOMAC (Western Ontario and Mcmaster Universities) scale. The type of patient undergoing primary arthroplasty was similar in the 15 different hospitals evaluated.The variability in baseline WOMAC score between hospitals in THR and TKR indication was described by range, mean and standard deviation (SD), mean and standard deviation weighted by the number of procedures at each hospital, high/low ratio or extremal quotient (EQ5-95), variation coefficient (CV5-95) and weighted variation coefficient (WCV5-95) for 5-95 percentile range. The variability in subjective and objective signs was evaluated using median, range and WCV5-95. The appropriateness of the procedures performed was calculated using a specific threshold proposed by Quintana et al for assessing pain and functional capacity. RESULTS. The variability expressed as WCV5-95 was very low, between 0.05 and 0.11 for all three dimensions on WOMAC scale for both types of procedure in all participating hospitals. The variability in the physical and mental SF-12 components was very low for both types of procedure (0.08 and 0.07 for hip and 0.03 and 0.07 for knee surgery patients). However, a moderate-high variability was detected in subjective-objective signs. Among all the surgeries performed, approximately a quarter of them could be considered to be inappropriate. CONCLUSIONS. A greater inter-hospital variability was observed for objective than for subjective signs for both procedures, suggesting that the differences in clinical criteria followed by surgeons when indicating arthroplasty are the main responsible factors for the variation in surgery rates.

Atypical Vascular Involvement in a Case of Behçet's Disease.

Introduction. Behçet's disease (BD) is a form of vasculitis of unknown etiology which is rare in our environment. It is characterized by a variety of clinical manifestations and usually affects young adults. Recurrent oral and genital ulcers are a characteristic and extremely frequent symptom, but mortality is linked with more significant symptoms such as aortic pseudoaneurysm, pulmonary pseudoaneurysm, and cerebral venous thrombosis. Patient and Method. We present a case of a young male with atypical BD and severe polyvascular involvement (previous cerebral venous thrombosis and current peripheral venous thrombosis, acute ischemia, and peripheral arterial pseudoaneurysm) who required urgent surgical intervention due to a symptomatic external iliac pseudoaneurysm. Result. The pseudoaneurysm was successfully treated, we performed an iliofemoral bypass, and we treated it with steroids and immunosuppressive therapy. Conclusions. These rare clinical manifestations highlight the importance of considering BD in young patients, even in usual cases of vascular intervention, whether arterial or venous in nature.

Incidents and complications of totally implanted vascular access devices in children: a prospective study.

BACKGROUND: Totally implanted vascular access devices are frequently used in children for repeated blood samples or intravenous treatments. This prospective study aims at identifying the risk factors associated with infections, obstructions and surgical complications of these devices in pediatric patients. METHODS: From January 2006 to January 2008, all children older than one year of age with a diagnosis of solid or blood cell malignancy were included in the study. Insertion was performed by the surgeon according to a standardized protocol after landmark-guided puncture of the subclavian or internal jugular vein by a senior anesthesiologist. Dressing and post-operative care were standardized. Every manipulation was prospectively recorded by specialized dedicated nurses, and all patients were screened for complications one month post-surgery. RESULTS: 45 consecutive patients 1 to 16 years old were enrolled in the study. Mean age at the time of procedure was 8.5 years (range 1.3-15.6; SD +/- 4.88). There were 12 peroperative adverse events in 45 procedures (27%), detailed as follows: 3 pneumothoraces (7%), 3 hematomas (7%), 6 arterial punctures (13%). Among these events, intervention was necessary for two pneumothorax and one arterial puncture. There was no air embolism. At one month, we recorded 5 post-operative complications (11%): 2 thrombotic obstructions, one unsightly scar, and one scapular pain of unknown etiology. One patient needed repositioning of the catheter. There was no catheter-related infection. CONCLUSION: Prospective recording of TIVA insertion in children reveals a significant number of early incidents and complications, mainly associated with the percutaneous puncture technique. We found no infection in this series. Results of a longer follow-up in the same population are pending.

Assessment of a sheep animal model to optimize photodynamic therapy in the oesophagus

Background and Objectives: Precursor lesions of oesophagus adenocarcinoma constitute a clinical dilemma. Photodynamic therapy (PDT) is an effective treatment for this indication, but it is difficult to optimise without an appropriate animal model. For this reason, we assessed the sheep model for PDT in the oesophagus with the photosensitiser meta-(tetra-hydroxyphenyl) chlorin (mTHPC). Materials and Methods: Twelve sheep underwent intravenous mTHPC injection, blood sampling and fluorescence measurements. mTHPC's pharmacokinetics was measured in vivo and in plasma by fluorescence spectroscopy. Biopsies of sheep oesophagus were compared to corresponding human tissue, and the mTHPC's biodistribution was studied under fluorescence microscopy. Finally, the sheep oesophageal mucosa was irradiated, 4 days after mTHPC's injection. Results: Histologically, the sheep and human oesophagus were closely comparable, with the exception of additional fatty tissue in the sheep oesophagus. mTHPC's pharmacokinetics in sheep and human plasmas were similar, with a maximum of concentration in the sheep 10 hours after i.v. injection. mTHPC's pharmacokinetics in vivo reached its maximum after 30-50 hours, then decreased to background levels, as in humans under similar conditions. Two days after injection, mTHPC was mainly distributed in the lamina propria, followed by a penetration into the epithelium. The sheep and human tissue sensitivity to mTHPC PDT was similar. Conclusion: In conclusion, this model showed many similarities with humans as to mTHPC's plasma and tissue pharmacokinetics, and for tissue PDT response, making it suitable to optimise oesophagus PDT. Lasers Surg. Med. 41:643-652,2009. (C) 2009Wiley-Liss,Inc.

The tumor antigens RHAMM and G250/CAIX are expressed in head and neck squamous cell carcinomas and elicit specific CD8+ T cell responses.

Despite advances in surgery, radio- and chemotherapy, therapeutic approaches for patients with head and neck squamous carcinoma (HNSCC) need to be improved. Immunotherapies eliciting tumor specific immune responses might constitute novel treatment options. We therefore investigated the expression and immunogenicity of two tumor-associated antigens (TAA) the receptor for hyaluronic acid mediated motility (RHAMM) and carboanhydrase IX (G250/CAIX) in HNSCC patients. Twenty-two HNSCC samples were examined for the expression of RHAMM and G250 by Western blotting and immunohistochemistry, 14/22 samples were tested for HLA-A2 expression by flow cytometry. For 8/22 samples single tumor-cell suspensions were generated, and mixed lymphocyte peptide cultures (MLPC) were performed to evaluate the frequencies of cytotoxic T cells specifically recognizing RHAMM and G250 using Tetramer staining/multi-color flow cytometry and enzyme linked immunosorbent spot (ELISPOT) assays. RHAMM and G250 were expressed in 73 and 80% of the HNSCC samples at the protein level. A co-expression of both TAAs could be detected in 60% of the patients. In 4/8 HLA-A2+ patients, 0.06-0.13% of CD8+ effector T cells recognized Tetramers for RHAMM or G250 and secreted IFNgamma and granzyme B in ELISPOT assays. RHAMM and G250 are expressed at high frequency and high protein level in HNSCCs and are recognized by cytotoxic CD8+ effector T cells. Therefore both TAAs constitute interesting targets for T cell based immunotherapies for HNSCC.

Intraoperative photodynamic therapy of the chest cavity in malignant pleural mesothelioma bearing rats.

BACKGROUND AND OBJECTIVE: Experimental assessment of anticancer effect, normal tissue damage, and toxicity of intrathoracic mTHPC-mediated photodynamic therapy (PDT) combined to surgery in malignant pleural mesothelioma (MPM) bearing rats. STUDY DESIGN/MATERIALS AND METHODS: Six days after implantation of syngenic malignant mesothelioma cells in the left chest cavity of Fischer rats (n = 21) and 4 days after sensitization (0.1 mg/kg mTHPC), a left-sided pneumonectomy was performed, followed by intraoperative light delivery (652 nm, fluence 20 J/cm(2)), either by spherical illumination of the chest cavity (fluence rate 15 mW/cm(2)) or by focal illumination of a tumor area (fluence rate 150 mW/cm(2)). Controls comprised tumor-bearing untreated animals, tumor-bearing animals undergoing pneumonectomy, and tumor-bearing animals undergoing pneumonectomy and light delivery without sensitization or sensitization without light delivery. No thoracocentesis was performed during follow-up. RESULTS: An invasively growing sarcomatous type of mesothelioma was found in all animals at day 10, without tumor necrosis in control animals. PDT resulted in 0.5-1 mm deep inhomogeneous tumor necrosis after spherical, and in a 1-2 mm deep tumor necrosis after focal illumination. No injury to mediastinal organs was observed, neither after PDT with spherical nor with focal light delivery except focal interstitial lung fibrosis at the mediastinal area of the opposite lung. All animals with pneumonectomy followed by spherical PDT of the entire tumor-bearing chest cavity died within 72 hours whereas all other animals survived. All animals that died presented massive pleural effusion. CONCLUSIONS: PDT following pneumonectomy in mesothelioma bearing rats was technically feasible and allowed to study its effect on tumor and normal tissues. PDT-related tumor necrosis was observed after spherical and focal light delivery, however, pneumonectomy followed by PDT with spherical light delivery to the tumor-bearing chest cavity resulted in fatal complications.