Macroscopic Infiltration Research Articles

CFD–DEM comparison of slurry infiltration in laboratory column tests and in real-world tunnelling

Slurry infiltration and filter cake formation are critical for excavation surface stability in slurry shield tunnelling. Laboratory column tests are frequently adopted to study macroscopic infiltration. However, these tests, in a vertical orientation and confined by an impermeable cylindrical boundary, may not be a good representation of horizontal infiltration into an unbounded stratum in real-world tunnelling. In this paper, a more realistic slurry pressure balance (SPB) tunnelling model was created to overcome the limitations of simulated laboratory column tests. Coupled computational fluid dynamics (CFD)–discrete element method (DEM) numerical simulations were carried out to study the slurry infiltration into sand for this model and compare the results with the conventional laboratory column test model. Both models produced the same types of filter cakes. The SPB tunnelling model yielded larger infiltration distances and ranges, but a lower normalised permeability in the sand region in front of the tunnel face. The fluid pressure within this region dissipated much faster in the SPB tunnelling model, resulting in rapid velocity decreases and a faster infiltration process. Although the SPB tunnelling model is more representative of real-world tunnelling, the conventional laboratory column test is conservative, producing similar types of filter cakes over a longer timeframe.

Kudo's pit pattern classification for in vivo optical diagnosis and discrimination of advanced colorectal polyps.

Colonoscopy is currently the basic diagnostic tool for the large intestine. The size of lesions assessed during the investigation is one criterion for assessing the risk of polyps transforming into colorectal cancer. The techno-logical development of endoscopes and the possibility of direct assessment of lesion's surface during the endoscopic examination and to use appropriate treatment. The aim of this study is to analyze the consistency between the histopathological assessment of high-risk lesions in colonoscopy and the determination according to Kudo's pit pattern classification. The analysis included the results of colonoscopies performed over a 2-year period, in which polyps were diagnosed endoscopically and either polypectomies were performed, or sections were taken from these polyps and a pit pattern analysis was done according to Kudo's classification. A total of 1038 patients (age, 67.2 ± 12.7 years) were enrolled in the study. Of the 1981 samples taken in total, polyps larger than 1 cm were found in 96 cases, laterally spreading tumors (LSTs) were found in 48 cases, and macroscopic infiltration or tumors were found in 110 cases. The results of the histopathological examination were obtained in 248 cases. A value of 4 or higher in the Kudo classification turned out to be the best parameter to differentiate malignant lesions from benign ones for lesions larger than 1 cm and laterally spreading tumors, with a sensitivity of 91.2% and a specificity of 70.4%. The assessment of polyps according to Kudo's classification is a useful tool for assessing the malignancy of lesions as part of a routine colonoscopy.

Improvement of rainwater infiltration and storage capacity by an enhanced seepage well: From laboratory investigation to HYDRUS-2D numerical analysis

Seepage well is an emerging Low Impact Development (LID) technology that can effectively control the storm runoff. However, its rainwater infiltration rate and storage capacity still require further enhancement. By setting a horizontal infiltration structure at the bottom of conventional rainwater seepage well (CSW), an enhanced seepage well (ESW) was proposed in this study, and its infiltration performances compared with the permeable pavement (PP) and the CSW were systemically investigated using static infiltration experiment and HYDRUS-2D simulation. The results showed that the infiltration efficiency of ESW was significantly higher than that of PP and CSW, and the process of water infiltrated through soil mainly controlled the macroscopic infiltration rate. The Nash-Sutcliff Efficient (NSE) index was used to evaluate the accuracy and reliability of the HYDRUS-2D model, and the results of NSE values greater than 0.75 (varied between 0.75 and 0.91) confirmed the applicability of HYDRUS-2D to describe correctly the hydraulic behavior of the ESW system. Simulation infiltration tests showed that the ESW performed a higher average infiltration rate and fewer total runoff volume than the CSW, indicating the effectively enhancement of the infiltration and water retention capacity of ESW, especially under heavy rainfall intensities. Additionally, the ESW system exhibited an excellent runoff-control and rainwater retention capacity in an actual rainfall scenario.

Allium tuberosum aqueous extract had curative effects on malignant melanoma in C57BL/6 mice

Cancer is still a disappointing public health problem worldwide; in this context medicinal plants could be visualized as a promising alternative for antitumor adjuvant therapy. Here the effect of Allium tuberosum (AT) aqueous extract on the evolution of B16F10 melanoma in C57BL/6 mice and on melanoma cells in vitro anaerobic metabolism were studied. 33 mice were divided in 4 groups: control melanoma (CM; n=7), AT given orally (ATO; n=9), AT and celecoxib given orally (ATCxO; n=7) and AT given orally and intratumorally (ATOI; n=10), to which 200,000 tumor cells were transplanted into the right leg hind paw. Clinical and pathological signs of malignant melanoma disease progression were evaluated in vivo, while anaerobic glycolysis and redox capacity using methylene blue were measured in vitro. AT aqueous extract were given therapeutically from the time of tumor onset. Results shown that ATO groups displayed longer survival time with decreased tumor growth, while ATOI group no tumor macroscopic infiltration and islands of degenerating extensive necrotic melanoma cells infiltrated by mononuclear cells and fibrosis were observed. In vitro, AT extract decreased anaerobic metabolism in a dose-dependent manner (IC50=1.13 mg/ml) and ATO tumor cells had a greater reductive capacity. In conclusion, AT had a cytotoxic curative effect on melanoma B16F10 in C57BL/6 mice related with a decreased anaerobic metabolism and increased redox capacity of cancer cells, indicating that AT counteracts Warburg´s effect favouring aerobic metabolism.

On the impact of porous media microstructure on rainfall infiltration of thin homogeneous green roof growth substrates

Green roofs are considered an attractive alternative to standard storm water management methods; however one of the primary issues hindering their proliferation is the lack of data regarding their ability to retain and reduce storm water under a variety of climatic conditions. This lack of data is partly due to the complexity of physical processes involved, namely the heterogeneous microscopic behavior that characterize flows in unsaturated porous media. Such an anomalous behavior is difficult to predict a priori, especially in the presence of layered structures. This paper examines water infiltration of a green roof at the pore-scale with the aim to evaluate the effect of the porous microstructure in thin substrate layers. In such layers, the thickness of the medium and the particle size are within the same order of magnitude and the effect of the packing arrangement on the flow dynamics can be pronounced. In this study, three packing arrangements and two different hydraulic heads, analogous to extreme rainfall events typical of Scandinavia, are investigated by means of direct numerical simulations based on the lattice Boltzmann method. The results show that a wider variability of pore sizes in a thin medium can be linked directly to flow pathing preference and consequently less homogenized flow in the primary flow direction. This situation corresponds to intermittent flow behavior at the pore-scale level and reduced macroscopic infiltration rates. This observation unveils the possibility of designing innovative green roof growth substrates: by tuning the particle size and thickness of the layers composing the medium the desired green roof detention time can be attained.

Tensile Fracture Behavior of Carbon Fiber/Al Composites Produced by the Liquid Extrusion Infiltration Technique

The liquid extrusion infiltration technique was used to fabricate two 2D CF/Al composites with T700 and T300 carbon fiber fabrics. Microstructure examination demonstrated their different macroscopic infiltration morphology, but the infiltration effect was perfect. The coefficient of thermal expansion of those two composites was shown to be much lower than that of the matrix alloy below 673 K (400°C). At a temperature higher than 673 K (400°C), this value for a T300 CF/Al composite was equivalent to only 22.6%, which was much smaller than that of the matrix alloy. The ultimate tensile strength of T700 CF/Al and T300 CF/Al composites was improved by factors of 2.007 and 2.467 than that of the matrix alloy, respectively. The differences in the thermal expansion coefficient and ultimate tensile strength stem from carbon fiber volume fractions and its grades of the two different fabrics. The fracture morphology of tensile specimens was also influenced by the fiber orientation in fabrics. A T300 CF/Al composite displayed better tensile and thermal expansion properties than a T700 CF/Al composite, which were prepared and designed for further industrial applications.

Ten-year survival outcomes of patients with potentially resectable gastric cancer: impact of clinicopathologic and treatment-related risk factors.

BackgroundDespite therapeutic advancements, gastric cancer (GC) remains a leading cause of death worldwide.MethodsThis retrospective cohort study statistically analyzed the clinicopathologic characteristics, treatments and outcomes of patients with potentially resectable GC managed at our institution between 2006 and 2010. The STROBE checklist was applied.ResultsPreoperative assessment of 164 GC patients (male: female ratio 1.87, median age 65 years) assigned 132 (80.5%) to total (56; 42.4%) or subtotal (76; 57.6%) gastrectomy. Resection margins were microscopically tumor-free (R0) in 100 (75.8%), microscopically infiltrated (R1) in 25 (18.9%) and macroscopically infiltrated (R2) in 7 (5.3%) patients. Nodal plane dissection was D0 in 34 (25.8%), D1 in 62 (47.0%) and D2 in 36 (27.3%) patients. Early GC was diagnosed in 19 patients (14.4%). Fluorouracil-based chemotherapy was administered in 69.7% and chemoradiation in 18.2% of patients. The 5- and 10-year survival rates of patients with R0 resection were 74% and 65.4%, respectively. The 2-year survival rates for R1 and R2 resection were 28.9% and 0% respectively. The 5- and 10-year survival rates according to nodal plane dissection were 55.6% and 41.4% for D2, and 53.2% and 49.7% for D1, respectively. On multivariate analysis, T4, N3 and R1/R2 remained independent negative prognostic factors for overall survival. Microscopic or macroscopic infiltration of surgical margins was the worst adverse prognostic factor for survival.ConclusionThese results are equivalent to those from centers of excellence and indicate the urgent need for improvements in the field, particularly in the development of predictive models to guide personalized therapy.

Prognostic value of microscopic evaluation of organ infiltration and visceral resection margins (VRM) in patients with retroperitoneal sarcomas (RPS).

11074 Background: Surgery with gross margin clearance (R0 and R1) is the standard treatment for RPS and visceral resection has been proposed even in the absence of macroscopic visceral infiltration. Formal definition and margin sampling procedures for pathological evaluation are lacking for RPS. This study investigated VRM as well as viscera infiltration and their association with patient survival. Methods: Consecutive patients operated on for primary RPS (2009-2014) were extracted from a prospectively maintained database. VRM were sampled for each resected organ and classified as negative and positive. Also, tumor infiltration of resected organs was classified as follow: absence of infiltration, infiltration of perivisceral fat, early infiltration (i.e., renal/adrenal capsule, muscular fascia, contact with muscular tunica of hollow viscera), and infiltration of the viscera. Results: In 207 patients VRM were negative in 182 (88%) and positive 25 (12%). Organ infiltration was absent, perivisceral, early, and visceral in 37 (18%), 13 (6%), 17 (8%), and 140 (68%), respectively. Overall survival analysis showed that patients with negative VRM plus organ infiltration (HR = 3.56; 95%CI 1.15-11.00, P = 0.028) and those with positive VRM irrespective of organ infiltration (HR = 7.76; 95%CI 2.18-27.65, P = 0.002) did worse that patients with negative VRM plus no organ infiltration, after adjustment from known prognostic features. Conclusions: After liberal multivisceral resection for primary RPS, up to 80% of patients have infiltrated organs at some extent, while VRM are positive in up to 10% of cases. Visceral resection is justified even in the absence of macroscopic infiltration. Systematic evaluation of microscopic involvement of adjacent viscera may stratify prognosis.

MP7-05 PROGNOSTIC VALUE OF THE PT3 SUBCLASSIFICATION FOR UPPER TRACT UROTHELIAL CARCINOMAS OF THE RENAL PELVICALYCEAL SYSTEM

You have accessJournal of UrologyBladder Cancer: Upper Tract TCC II1 Apr 2015MP7-05 PROGNOSTIC VALUE OF THE PT3 SUBCLASSIFICATION FOR UPPER TRACT UROTHELIAL CARCINOMAS OF THE RENAL PELVICALYCEAL SYSTEM Thomas Seisen, Eva Compérat, Pierre Colin, Priscilla Léon, Laurent Nison, Gregory Bozzini, Christian Pfister, Laurent Guy, Alain Ruffion, Jean Luc Descotes, Jacques Irani, Alexandre De La Taille, Thierry Lebret, Olivier Cussenot, Shahrokh Shariat, and Morgan Rouprêt Thomas SeisenThomas Seisen More articles by this author , Eva CompératEva Compérat More articles by this author , Pierre ColinPierre Colin More articles by this author , Priscilla LéonPriscilla Léon More articles by this author , Laurent NisonLaurent Nison More articles by this author , Gregory BozziniGregory Bozzini More articles by this author , Christian PfisterChristian Pfister More articles by this author , Laurent GuyLaurent Guy More articles by this author , Alain RuffionAlain Ruffion More articles by this author , Jean Luc DescotesJean Luc Descotes More articles by this author , Jacques IraniJacques Irani More articles by this author , Alexandre De La TailleAlexandre De La Taille More articles by this author , Thierry LebretThierry Lebret More articles by this author , Olivier CussenotOlivier Cussenot More articles by this author , Shahrokh ShariatShahrokh Shariat More articles by this author , and Morgan RouprêtMorgan Rouprêt More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.212AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES To assess the prognostic value of the pT3 subclassification for the upper tract urothelial carcinomas (UTUCs) of the renal pelvicalyceal system. METHODS The study population consisted of 89 patients diagnosed with pT3 UTUC of the renal pelvicalyceal system. A central pathology review was performed to categorize tumors as pT3a (microscopic infiltration of the renal parenchyma) or pT3b (macroscopic infiltration of the renal parenchyma and/or infiltration of peripelvic adipose tissue). Kaplan Meier method and log-rank test have been used to analyze recurrence-free (RFS), cancer-specific (CSS) and overall (OS) survivals according to the subclassification of pT3 UTUCs. Univariate and multivariate Cox regression analyses have been conducted to determine predictors of recurrence, and cancer-specific or overall mortality. RESULTS Overall, 48 (54%) and 41 (46%) tumors were classified as pT3a and pT3b, respectively. Patients with pT3b disease were more likely to develop high-grade tumors (p=0.001) with lymphovascular invasion (p=0.02) and lymph node metastases (p=0.01). The five-years RFS (54% vs 59%; p=0.001) and CSS (53% vs 61%; p=0.03) rates were lower in patients with pT3b tumors. In multivariable analysis, subclassification pT3b was an independent predictor of both disease recurrence (HR=1.7; p=0.001) and cancer specific mortality (HR=1.5; p=0.003). However, the subclassification of pT3 tumors was not independently correlated with overall mortality (HR=1.1; p=0.16). CONCLUSIONS The prognosis of pT3 UTUCs of the renal pelvicalyceal system is linked with the depth of infiltration in the renal parenchyma and peripelvic adipose tissue. This subclassification might help to identify patients who are at increased risk of recurrence or specific death. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e65 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Thomas Seisen More articles by this author Eva Compérat More articles by this author Pierre Colin More articles by this author Priscilla Léon More articles by this author Laurent Nison More articles by this author Gregory Bozzini More articles by this author Christian Pfister More articles by this author Laurent Guy More articles by this author Alain Ruffion More articles by this author Jean Luc Descotes More articles by this author Jacques Irani More articles by this author Alexandre De La Taille More articles by this author Thierry Lebret More articles by this author Olivier Cussenot More articles by this author Shahrokh Shariat More articles by this author Morgan Rouprêt More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Stan spoidła przedniego u chorych na raka krtani

Aim of the workAssessment of directions and ways of cancer spreading in the anterior commissure of the larynx, depending on the tumor location, age, sex of patients in a clinical trial and in microscopic serial section study. Materials and methodsThe study included 50 larynx preparations obtained from open partial and total laryngectomies (F-7; M-43). For the assessment of larynx anterior commissure microscopic status 28 larynx preparations with macroscopic free anterior commissure were used. For study of the directions and ways of tumor spreading in the anterior commissure served 22 larynx with macroscopic infiltration of anterior commissure. Anterior Commissure (AC) and TNM classifications was used to determine the location and tumor stage. Larynx anterior commissure was extracted and divided into 3 subregions: supraglottic, glottic and subglottic. ResultsThe direction and the way of cancer propagation in larynx anterior commissure structures is dependent on morphological changes that occur with aging. Cancer spreads in the anterior commissure along the fibers anchoring voice muscle within the Broyles ligament and is seen in tumor cells microembolism. ConclusionsIn patients with cancer of the larynx without macroscopically visible neoplastic lesions in the anterior commissure, cannot be excluded its microinfilration. Changed with age anterior commissure’ Broyles ligament by the process of neovascularization and ossification is not an effective protection against the spread of cancer. Directions and the ways of cancer spread in the anterior commissure is similar in men and women. AC classification can be important in qualifying patients for organ preservation surgery and should be supplemented by an additional AC4 degree, taking into account subglottic changes in the anterior commissure of the larynx.

International validation of the prognostic value of subclassification for AJCC stage pT3 upper tract urothelial carcinoma of the renal pelvis

What's known on the subject? and What does the study add? Tumour stage is a powerful predictor of clinical outcomes and the most important factor driving clinical decision-making after radical nephroureterectomy (RNU) in upper tract urothelial carcinoma (UTUC). It has been suggested that renal pelvic pT3 subclassification into microscopic infiltration of the renal parenchyma (pT3a) versus macroscopic infiltration or invasion of peripelvic adipose tissue (pT3b) has strong prognostic value. This is an external validation study of the prognostic value of pT3 subclassification of renal pelvic UTUC in a large international cohort of patients treated with RNU. pT3b UTUC is associated with features of aggressive tumour biology, disease recurrence and cancer-specific mortality. However, pT3 subclassification is not an independent predictor of clinical outcomes. To externally validate the prognostic value of subclassification of pT3 renal pelvic upper tract urothelial carcinoma (UTUC) in a large international cohort of patients treated with radical nephroureterectomy (RNU). The RNU specimens with pT3 UTUC of the renal pelvis from 284 patients at 11 centres located in Asia, North America and Europe were retrospectively evaluated. All specimens were reviewed by genitourinary pathologists at each institution. Tumours were categorized as pT3a (microscopic infiltration of the renal parenchyma) or pT3b (macroscopic infiltration of the renal parenchyma and/or infiltration of peripelvic adipose tissue). Overall, 148 (52%) tumours were classified as pT3a and 136 (48%) as pT3b. Patients with pT3b disease were more likely to have high-grade tumours and sessile tumour architecture (all P ≤ 0.02). Patients with pT3b tumours were at increased risk of disease recurrence (5-year estimates: 55% versus 42%, P = 0.012) and cancer-specific mortality (CSM) (5-year estimates: 48% versus 40%, P = 0.04). Lymph node status, tumour architecture and tumour grade were independently associated with disease recurrence, whereas lymph node status, tumour architecture and lymphovascular invasion were independently associated with CSM. Subclassification of pT3 tumours was not associated with recurrence or CSM in multivariable analyses. Patients with pT3b UTUC were more likely to have tumours with aggressive pathological features and were at higher risk of disease recurrence and CSM after RNU compared with patients with pT3a disease. However, the pT3 subclassification did not remain an independent predictor of disease recurrence or CSM after controlling for tumour grade, lymph node status, tumour architecture and lymphovascular invasion.

Subclassification of pT3 Urothelial Carcinoma of the Renal Pelvicalyceal System is Associated With Recurrence-Free and Cancer-Specific Survival: Proposal for a Revision of the Current TNM Classification

BackgroundThe clinical course of pT3 upper tract urothelial carcinoma (UTUC) is highly variable. ObjectivesThe aim of the current study was to validate the clinical and prognostic importance of pT3 subclassification in the renal pelvicalyceal system in a large international cohort of patients. Design, setting, and participantsFrom a multi-institutional international database, 858 renal pelvicalyceal tumors treated with radical nephroureterectomy (RNU) were systematically reevaluated by genitourinary pathologists. Category pT3 pelvic tumors were categorized as pT3a (infiltration of the renal parenchyma on a microscopic level only) versus pT3b (macroscopic infiltration of the renal parenchyma and/or infiltration of peripelvic adipose tissue). InterventionRNU. MeasurementsAssociations of pT3 subclassifications with clinicopathologic features were assessed with the chi-square test. Prognostic impact was assessed with the log-rank test and multivariable Cox regression analyses. Results and limitationsOf 858 patients with renal pelvicalyceal tumors, 266 (31%) had pT3 disease. Of these, 146 (54.9%) were classified as pT3a and 120 (45.1%) as pT3b. Compared with pT3a, pT3b cancers were associated with higher tumor grade, nodal disease, and tumor necrosis. Ten-year recurrence-free (pT3a 58% vs pT3b 38%; p<0.001) and cancer-specific (pT3a 60% vs pT3b 39%; p=0.002) survival rates were lower for patients with pT3b disease. In multivariable analyses, classification pT3b was an independent predictor of both disease recurrence (hazard ratio [HR]: 1.8, p=0.003) and cancer-specific mortality (HR: 1.7; p=0.02). The major limitation is the retrospective character of the study. ConclusionsSubclassification of pT3 renal pelvicalyceal UTUC helps identify patients who are at increased risk of disease progression and cancer-related death. Further research may help assess the value of subclassification and its inclusion in future editions of the American Joint Committee on Cancer–International Union Against Cancer TNM classification system.

Treatment of Merkel Cell Carcinoma with Radiotherapy and Imiquimod (Aldara): A Case Report

Merkel cell carcinoma (MCC) is a rare skin tumor occurring mostly in older people. Postoperative radiotherapy is strongly recommended to improve local control. A case of a MCC treated by radiotherapy associated with imiquimod (Aldara) is presented. A possible physiopathological rationale for this concomitant treatment is also given. We treated a diabetic 82-year-old man presenting with a MCC of the right zygomatic area. Despite surgery, postoperative ultrasonography showed a firm, painless residual mass of about 11 x 10 cm, fixed to the deep tissues. Parotid and zygomatic areas were treated along with the ipsilateral laterocervical lymph nodes. The total dose to the planning target volume was 50.4 Gy (1.8 Gy/day). Imiquimod was applied once a day to the zygomatic area with macroscopic infiltration and to the surrounding erythema. During the combination treatment, the patient showed acute G3 skin toxicity (RTOG) and a scab that resolved after a 3-week interruption of the radiotherapy and imiquimod treatment. When the scab was removed, the underlying skin appeared completely re-epithelialized. Imiquimod was suspended and treatment was continued only with irradiation. During this second phase of the treatment, the patient developed G2 dermatitis and G2 stomatitis. Clinical and instrumental re-evaluation showed a complete response 7 months after the end of radiotherapy, with very good local tropism. This case report suggests the possible effective use of immunomodulators, in this case imiquimod, combined with radiation therapy for cutaneous malignancies such as MCC. Skin tolerance should be an important issue to consider.

Long-term results with exophthalmos in a surgical series of 30 sphenoorbital meningiomas

The authors analyzed the long-term results and radiological aspects of sphenoorbital meningioma (with emphasis on exophthalmos) in a series of 30 patients who underwent resection. Data obtained in all 30 patients who underwent surgery for typical sphenoorbital meningioma at the authors' institution between June 1994 and September 2005 were analyzed retrospectively. The exophthalmos index (EI) was measured on preoperative MR images and/or CT scans and compared between the early and last follow-up examinations. All patients were women 35-74 years of age (median 51 years). Exophthalmos was the presenting symptom in 28 patients (93%), and was observed on preoperative MR images in all patients. The median duration of symptoms before surgery was 10 months (2-120 months). Total resection (Simpson Grade I) was not achieved in these patients because of the impossibility of resecting the dura mater in the superior orbital fissure without causing significant complications. Subtotal resection (Simpson Grade II) was obtained in 90% of patients, and in 3 patients (10%) a portion of the tumor was deliberately left in place because of extensive macroscopic infiltration of the cavernous sinus and/or extraocular muscles (Simpson Grade III). No patient died. Radiological evaluation at a median follow-up of 61 months (range 17-136 months) showed no contrast enhancement in 14 patients (47%), residual contrast enhancement without evolution in 13 (43%), and recurrence (new contrast enhancement) in 3 (10%). The EI was improved at the first radiological follow-up (median 12 months) in 27 patients (90%), and at the last radiological follow-up (median 61 months) in 28 patients (93%). In the interval between the first and final imaging follow-up, the EI improved in only 8 patients (20%), worsened in 15 patients (50%), and showed no variation in 7 patients (30%). Sphenoorbital meningiomas are insidious tumors with slow progression. Even when exophthalmos is not clinically evident, it is always present on preoperative MR imaging. Total resection is not possible due to superior orbital fissure invasion, but subtotal resection (Simpson Grade II) can assure long-term stability due to the nonevolutive nature of most residual tumors. Exophthalmos improves at early radiological follow-up, but may worsen again as time passes.

“Grey Zone” Patterns of Unexplained Endocarditis: Still a Challenge for Clinical Decision Making

The authors report two cases of unexplained active inflammatory endocarditis with totally different clinical presentations. The patients had undergone previous mitral repair surgery and were referred for multiple soft mobile masses on the mitral ring without clinical or laboratory signs of endocarditis. Serologic screening and blood culture results were negative, including those for specific fastidious bacteria, as well as immunologic tests to rule out "nonbacterial thrombotic endocarditis." Before new surgery, both patients were treated with long-term antibiotic and anticoagulant therapy, with no significant changes in clinical setting and echocardiographic patterns. In neither case was it possible to characterize a specific microorganism: the intraoperative findings were highly evocative of active endocarditis with a macroscopic infiltration of the mitral ring, and culture results from surgical material and valvular tissue were negative.

A Geometrical Pore Model for Estimating the Microscopical Pore Geometry of Soil with Infiltration Measurements

This paper presents a simple geometrical pore model designed to relate characteristic pore radii of the porous network of soils with macroscopic infiltration parameters. The model composed of a stack of spherical hollow elements is described with two radii values: the pore access radius and the actual pore radius. The model was compared to cylindrical pore models and its mathematical consistency was assessed. Soil sorptivity S and the second parameter A of the Philip infiltration equation (1957), have been determined by numerically simulated infiltration. A diagram and an empirical relation have been set in order to relate the pore access and pore radii to the infiltration parameters S and A. The consistency of the model was validated by comparing the predicted sorptivity and hydraulic conductivity values, with the widely used unsaturated soil hydraulic functions (van Genuchten, 1980). The model showed good agreement with experimental infiltration data, and it is therefore concluded that the use of a model with two radii improves the relation between microscopic pore size and macroscopic infiltration parameters.

Parotid gland carcinoma: surgical strategy based on local risk factors.

To evaluate the best surgical strategy in cases of parotid gland carcinoma, local risk factors (T, N, histology, and treatment) were analyzed in a series of 134 patients. The efficacy of the facial nerve sacrifice in case of macroscopic tumor infiltration was tested by means of survival analyses (Kaplan-Meier and Cox algorithms). This study demonstrated that nerve preservation resulted in a better prognostic value when compared with resection only in the group of patients having a T1 or T2. In patients affected by T3 and T4, the different treatment did not show any difference in survival rate. In conclusion, the sacrifice of the facial nerve is not always able to improve the survival rate.

Liquid silicon infiltration: description of infiltration dynamics and silicon carbide formation

This article presents a model for the numerical simulation of liquid silicon infiltration into porous carbon/carbon preforms. Based upon the special morphology of the preforms, capillary flow has been modelled using a one-dimensional solution of the Navier-Stokes equations. To calculate macroscopic infiltration behaviour of porous components like plates or tubes, microscopic capillary flow phenomena have been linked with macroscopic silicon concentration via the statistical distribution function of capillary diameters. As a result, the time dependence of silicon concentration during infiltration as well as silicon distribution in the ceramic end-product can be calculated. The same model is also suitable for calculating the degree of silicon conversion to silicon carbide and therefore the phase composition of the fabricated ceramic material. Simulation values of silicon concentration and phase composition show good accordance with experimental measurements.

Prognostic factors and outcome of incompletely resected invasive thymoma following radiation therapy.

Stage III and stage IV thymomas with significant macroscopic infiltration to the neighboring structures are rarely completely resectable. It therefore remains unclear to what extent tumors must be surgically debulked to improve prognosis. We reviewed the cases of 31 patients with incompletely resected invasive thymoma and residual macroscopic disease who were referred to postoperative irradiation. Survival and local tumor control were analyzed. All patients were treated between 1958 and 1990 with megavoltage irradiation at doses ranging from 42 to 66 Gy. The shortest follow-up time for living patients was more than 5 years. The overall median 5-year survival rate was 45%. Eighteen stage III patients had a 5-year survival rate of 61% and a 10-year survival rate of 57%. Thirteen patients had stage IV disease and 5- and 10-year survival rates of 23% and 8%, respectively. Univariate and multivariate analyses confirmed a worse prognosis for stage IV disease. Epithelial or spindle-cell thymoma was associated with stage IV disease. Twenty-two percent of patients with stage III disease had epithelial or spindle-cell thymoma, versus 69% of patients with stage IV disease (P = .02 for univariate and P = .05 for multivariate analysis). Initial tumor diameter greater than 10 cm correlated with poor prognosis in the univariate analysis (P = .05). However, more importantly, debulking of tumor did not significantly improve outcome when compared with patients who received biopsy only. The median survival rate of patients with stage IVa disease did not differ from that of those with stage IVb disease. Mediastinal control was achieved in 23 patients (74%). Stage IV disease did not correlate with an increase in local treatment failure after irradiation, although epithelial or spindle-cell thymoma predisposed for local treatment failure (46% v 11%; P = .04 in univariate and P = .055 in multivariate analysis). Tumor debulking leaving macroscopic residual thymoma, as opposed to biopsy alone, does not improve prognosis when followed by radiation. Radiation therapy for local tumor control is most effective in nonepithelial-predominant thymomas.

Invasiveness in in vitro and clinical evaluation of meningiomas

Fragments of freshly isolated human meningiomas were cultured in vitro to form cell monolayers. These monolayers were confronted with embryonic chick heart fragments in vitro for 1, 2, 4, and 7 days. Microscopically, three different histological patterns were observed. Type I included necrotized meningial cells; type II presented surviving meningial cells; type III included meningial cells that had invaded the host tissue. The clinical analysis included the histopathological diagnosis, the macroscopic situation at surgical intervention, and the follow-up with or without recurrence. Correlation between these clinical parameters and the in vitro results demonstrated that type III confrontations correlated with macroscopic infiltration in the brain parenchyma and tumor recurrence. Invasiveness in vitro was seen in two anaplastic and two transitional meningiomas.