Light depolarization induced by metallic tips in apertureless near-field optical microscopy and tip-enhanced Raman spectroscopy

We have investigated the depolarization effects of light scattered by sharp tips used for apertureless near-field optical microscopy. Dielectric and metal coated tips have been investigated and depolarization factors between 5 and 30% have been measured, changing as a function of the incident light polarization and of the tip shape. The experimental results are in good agreement with theoretical calculations performed by the finite element method, giving a near-field depolarization factor close to 10%. The effect of depolarization has been investigated in polarized tip-enhanced Raman spectroscopy (TERS) experiments; the depolarization gives rise to forbidden Raman modes in Si crystals.

Validation of individual and multiple-sequential interventions for reduction of microbial populations during processing of poultry carcasses and parts

Changes in aerobic plate counts (APC), total coliform counts (TCC), Escherichia coli counts (ECC), and Salmonella incidence on poultry carcasses and parts and in poultry processing water were evaluated. Bacterial counts were estimated before and after individual interventions and after poultry carcasses were exposed to multiple-sequential interventions at various stages during the slaughter process. Individual and multiple-sequential interventions were evaluated at three processing plants: (i) plant A (New York wash, postevisceration wash, inside-outside bird washes 1 and 2, chlorine dioxide wash, chlorine dioxide wash plus chlorine chiller, chiller exit spray, and postchiller wash), (ii) plant B (New York wash, inside-outside bird washes 1 and 2, trisodium phosphate wash, and chlorine chiller), and (iii) plant C (trisodium phosphate wash and chlorine chiller). The majority of individual interventions effectively or significantly (P < 0.05) reduced microbial populations on or in carcasses, carcass parts, and processing water. Reductions in APC, TCC, and ECC due to individual interventions ranged from 0 to 1.2, 0 to 1.2, and 0 to 0.8 log CFU/ml, respectively. Individual interventions reduced Salmonella incidence by 0 to 100% depending on the type of process and product. Multiple-sequential interventions resulted in significant reductions (P < 0.05) in APC, TCC, ECC, and Salmonella incidence of 2.4, 2.8, and 2.9 log CFU/ml and 79%, respectively, at plant A; 1.8, 1.7, and 1.6 log CFU/ml and 91%, respectively, at plant B; and 0.8, 1.1, and 0.9 log CFU/ml and 40%, respectively, at plant C. These results enabled validation of in-plant poultry processing interventions and provide a source of information to help the industry in its selection of antimicrobial strategies.

Giant solitary fibrous tumour of the meninges: MR-pathological correlation

The authors present the clinical, MR imaging and pathological features of the largest intracranial solitary fibrous tumour of the meninges ever reported in the literature. This well-circumscribed dural-based tumour strikingly demonstrated two different solid components. The first one demonstrated a suggestive T2 hypointensity that strongly enhanced after gadolinium administration while the other showed more classic homogeneous T2 hyperintensity and mild enhancement. These two components were also identifiable on the pathological examination, allowing an interesting imaging-histological correlation. Differential diagnoses of this rare extra-axial lesion are discussed.

Histologically malignant solitary fibrous tumor of the orbit

An intra-conical histologically malignant solitary fibrous tumor of the orbit presented in a 28 year-old female with intact vision and exophthalmos. Total resection was achieved by means of a frontal craniotomy and orbital roof osteotomy. Evidence of a beneficial role for adjuvant treatments in this particular tumor is controversial and vision impairment is a possible side effect. Therefore they were not employed. The patient is well after two years of follow-up.

Location of bung bagging during beef slaughter influences the potential for spreading pathogen contamination on beef carcasses

Preevisceration carcass washing prior to bung bagging during beef slaughter may allow pooling of wash water in the rectal area and consequent spread of potential pathogens. The objective of this study was to compare protocols for bung bagging after preevisceration washing with an alternative method for bung bagging before preevisceration washing for the potential to spread enterohemorrhagic Escherichia coli, E. coli O157:H7, and Salmonella on carcass surfaces. The study evaluated incidence rates of pathogens in preevisceration wash water (10 ml) samples (n = 120) and on surface (100 cm2) sponge samples (n = 120) in the immediate bung region when bagging occurred before (prewash bagging) and after (postwash bagging) preevisceration washing. Surface sampling from postwash bagging yielded incidence rates of 58.3, 5, and 8.3%, whereas wash water sampling yielded 28.3, 1.7, and 5% for enterohemorrhagic Escherichia coli, E. coli O157:H7, and Salmonella, respectively. Surface sampling from prewash bagging yielded incidence rates of 35, 1.7, and 0%, whereas wash water sampling yielded 18.3, 0, and 8.3% for enterohemorrhagic Escherichia coli, E. coli O157:H7, and Salmonella, respectively. Results of this research indicate that the rectal area is a significant source of pathogen contamination on carcasses and that wash water is an important mechanism for potential transfer of pathogen contamination from the rectal area. Results from this study suggest that bung bagging, as proposed in this study, before (prewash bagging) rather than after (postwash bagging) preevisceration washing was generally more effective in controlling pathogen contamination and potential spread from the rectal area of carcasses.

Alternative cutting methods to minimize transfer of nervous system tissue during steak preparation from bone-in short loins

Fresh beef products, such as steaks, may become contaminated with potential specified risk materials (SRMs), such as central nervous system tissue, during the fabrication of bone-in loin subprimals. The objective of this study was to evaluate current and alternative cutting methods that could be used to minimize the transfer of nervous system tissue (NST) tissue during preparation of steaks from bone-in short loins. Bone-in short loins were cut according to three methods. (i) Cutting method I-The vertebral column bones were removed prior to cutting the loin into steaks from the medial (vertebral column) to lateral (flank) side. (ii) Cutting method II--The loin was cut into steaks from the vertebral column side to the flank side prior to removal of the vertebral column bones. (iii) Cutting method III--The loin was cut into steaks from the flank side to the vertebral column side prior to removal of the vertebral column bones. Results indicated that surface areas along the vertebral column cutting line had detectable (0.10 and 0.22% NST/100 cm2) and, thus, higher potential SRM contamination than resulting steak surfaces or the cutting blade. Overall, there were no detectable (<0.10% NST/100 cm2) differences in NST contamination of steaks produced by the three cutting methods. Immunohistochemical evaluation of areas on excised and ground steak surfaces indicated that regardless of cutting method, there was generally "no" to "moderate" staining, suggesting that detectable (0.137 to 0.201% NST) contamination from these samples was most likely due to peripheral nerve detection. These results imply that steaks may be cut from bone-in short loins prior to removal of the vertebral column bones without affecting the transfer of NST to resulting steaks at concentrations <0.10% NST/100 cm2.

Microbiological status of fresh beef cuts

Fresh beef samples (n = 1,022) obtained from two processing plants in the Midwest (July to December 2003) were analyzed for levels of microbial populations (total aerobic plate count, total coliform count, and Escherichia coli count) and for the presence or absence of E. coli O157:H7 and Salmonella. A fresh beef cut sample was a 360-g composite of 6-g portions excised from the surface of 60 individual representative cuts in a production lot. Samples of fresh beef cuts yielded levels of 4.0 to 6.2, 1.1 to 1.8, and 0.8 to 1.0 log CFU/g for total aerobic plate count, total coliform count, and E. coli count, respectively. There did not appear to be substantial differences or obvious trends in bacterial populations on different cuts. These data may be useful in establishing a baseline or a benchmark of microbiological levels of contamination of beef cuts. Mean incidence rates of E. coli O157:H7 and Salmonella on raw beef cuts were 0.3 and 2.2%, respectively. Of the 1,022 samples analyzed, cuts testing positive for E. coli O157:H7 included top sirloin butt (0.9%) and butt, ball tip (2.1%) and for Salmonella included short loins (3.4%), strip loins (9.6%), rib eye roll (0.8%), shoulder clod (3.4%), and clod, top blade (1.8%). These data provide evidence of noticeable incidence of pathogens on whole muscle beef and raise the importance of such contamination on product that may be mechanically tenderized. Levels of total aerobic plate count, total coliform count, and E. coli count did not (P > or = 0.05) appear to be associated with the presence of E. coli O157:H7 and Salmonella on fresh beef cuts. E. O157:H7 was exclusively isolated from cuts derived from the sirloin area of the carcass. Salmonella was exclusively isolated from cuts derived from the chuck, rib, and loin areas of the carcass. Results of this study suggest that contamination of beef cuts may be influenced by the region of the carcass from which they are derived.

Incidence of enterohemorrhagic Escherichia coli, Escherichia coli O157, Salmonella, and Listeria monocytogenes in retail fresh ground beef, sprouts, and mushrooms

The objective of this study was to determine the prevalence of enterohemorrhagic Escherichia coli (EHEC), E. coli O157, Salmonella, and Listeria monocytogenes in retail food samples from Seattle, Wash. A total of 2,050 samples of ground beef (1,750 samples), mushrooms (100 samples), and sprouts (200 samples) were collected over a 12-month period and analyzed for the presence of these pathogens. PCR assays, followed by culture confirmation were used to determine the presence or absence of each organism. Of the 1,750 ground beef samples analyzed, 61 (3.5%) were positive for EHEC, and 20 (1.1%) of these were positive for E. coli O157. Salmonella was present in 67 (3.8%) of the 1,750 ground beef samples. Of 512 ground beef samples analyzed, 18 (3.5%) were positive for L. monocytogenes. EHEC was found in 12 (6.0%) of the 200 sprout samples, and 3 (1.5%) of these yielded E. coli O157. Of the 200 total sprout samples, 14 (7.0%) were positive for Salmonella and none were positive for L. monocytogenes. Among the 100 mushroom samples, 4 (4.0%) were positive for EHEC but none of these 4 samples were positive for E. coli O157. Salmonella was detected in 5 (5.0%) of the mushroom samples, and L. monocytogenes was found in 1 (1.0%) of the samples.

Microtensile adhesion of sealants to intact enamel

Contamination of etched enamel with saliva has been shown to result in sealant failure. Hydrophilic adhesives improve retention of sealants when enamel is contaminated.

OBJECTIVE

The objective of the present study was to characterize the adhesion of two sealants to unprepared enamel etched with phosphoric acid or conditioned with the all-in-one, self-etch adhesive Adper Prompt L-Pop.

METHODS

The two proximal enamel surfaces of 16 sound molars were assigned to four conditioning regimens: (1) 35% phosphoric acid for 15 s; (2) Adper Prompt L-Pop, one layer light-cured prior to sealant placement; (3) Adper Prompt L-Pop, two layers light-cured prior to sealant placement; and (4) Adper Prompt L-Pop, one layer co-cured with sealant. One of two sealants, i.e. Clinpro or Delton DDS, was applied, light-cured, followed by a composite build-up to provide support for microtensile bond testing.

RESULTS

The highest mean bond strengths were obtained when Adper Prompt L-Pop was applied in two layers and light-cured prior to the insertion of Clinpro Sealant. Co-cure of Adper Prompt L-Pop with either sealant resulted in bond strengths which were not significantly different from those of the phosphoric acid control. The use of Adper Prompt L-Pop in one layer cured prior to sealant placement resulted in statistically lower bond strengths than any other application technique regardless of the sealant used. Clinpro Sealant resulted in statistically higher bond strengths than Delton DDS Sealant.

CONCLUSIONS

Application of one layer of Adper Prompt L-Pop co-cured with the sealant resulted in bond strengths similar to those obtained with phosphoric acid etching.

Contribution of intraoperative electrical stimulations in surgery of low grade gliomas: a comparative study between two series without (1985-96) and with (1996-2003) functional mapping in the same institution

OBJECTIVES

Despite the growing use of intraoperative functional mapping in supratentorial low grade glioma (LGG) surgery, few studies have compared series of patients operated on without and with direct electrical stimulation (DES) by the same team. The present study compared the rate of LGG surgery performed in eloquent areas, the rate of postoperative sequelae, and the quality of resection during two consecutive periods in the same department-the first without and the second with the use of intraoperative electrophysiology.

METHODS

Between 1985 and 1996, 100 patients harbouring a supratentorial LGG underwent surgery with no functional mapping (S1). Between 1996 and 2003, 122 patients were operated on in the same department for a supratentorial LGG using intraoperative cortico-subcortical DES (S2).

RESULTS

Comparison between the two series showed that 35% of LGGs were operated on in eloquent areas in S1 versus 62% in S2 (p<0.0001), with 17% severe permanent deficits in S1 versus 6.5% in S2 (p<0.019). On postoperative MRI, 37% of resections were subtotal and 6% total in S1 versus 50.8% and 25.4%, respectively, in S2 (p<0.001). In both groups, survival was significantly related to the quality of resection.

CONCLUSIONS

The results of the present study allow, for the first time, quantification of the contribution of intraoperative DES in LGG resection. Indeed, the use of this method leads to the extension of indications of LGG surgery within eloquent areas; to a decrease in the risk of sequelae; and to improvement of the quality of tumour resection, with an impact on survival.

Effet de la grandeur décimale sur la lecture de chiffres dans les gliomes du carrefour gauche

An increasing number of studies are focusing on the anatomo-functional organisation of number processing and some cognitive models have been recently developed. Nevertheless, relationships between areas implicated in number processing, and language areas and circuits remain unclear. Recently, Dehaene and Cohen, in their "triple-code model of number processing", (Dehaene and Cohen, 1995) distinguished two alternative number representation and processing systems: one depending on verbal processes, the other representing a quantity manipulation. According to this model, the retrieval of "arithmetical facts" (AF), learned by rote at school and memorised in a verbal form (such as the multiplication table or simple addition problems) can be considered as a verbal automatism; conversely, subtraction problems, which require mental manipulation of the quantities, represent an abstract, semantic elaboration: "Actual Calculation" (AC). The anatomical correlate of the retrieval of AF (depending on automatic verbal associations) seems to correspond to the left-hemispheric perisylvian areas, while impairment of the actual calculation (AC) depends on the intraparietal region, particularly in the left dominant hemisphere. The present study describes the neuropsychological assessment of three patients, tested after surgery for left parieto-occipital tumors. Two of them were affected by an anaplasic glioma, the third by a low-grade glioma. The cognitive evaluation included: words of Rey, numeral (directed and reversed) span, reading of "simple" numbers (from 1 to 10) and of "complex" numbers (many decimals), writing (dictation) and reading a standard text, finger denomination and right-left distinction. All patients showed language disturbances, dysgraphia and severe dyslexia. In reading numbers, we identified two types of errors: lexical and syntactic. "Lexical errors" consisted in a wrong choice among words in the number's lexicon. For instance, all patients made errors in reading "complex" numbers composed by many decimals, switching single numbers but respecting the decimal size and the structure of the whole number (such as 69107 instead of 68107). On the other hand, only one patient committed syntactic errors, misunderstanding the decimal size and the structure of the number. We considered lexical errors as verbal errors, and syntactic errors as semantic errors, affecting the notion of quantity. We tried to explain verbal disturbances as well as lexical errors as a consequence of lesion of the left-hemispheric perisylvian areas, while syntactic errors as a consequence of impairment of the intraparietal region.

Cystic Tumors of the Kidney. Revision of the Literature and Authors'Cases

The authors report the clinico-pathological features of the so-called “cystic tumors of the kidney”, discussing data of the English literature and providing grossly and histologically illustrations. The following tumor entities will be discussed in detail: “cystic multilocular renal cell carcinoma”, “cystic nephroma”, “cystic partially differentiated nephroblastoma” and mixed (benign or malignant) epithelial/stromal tumor. The awareness of these clinico-pathologic entities by Urologist is important to assure patient a correct treatment and prognostic informations.

Immunocytochemical analysis of dentin: A double-labeling technique

Immunocytochemical analysis is a fundamental and selective technique for identifying different molecular components of human dental structure. The hypothesis tested here is that the application of different etching solutions on dentin does not hinder collagen fibrils and proteoglycans from maintaining their immunochemical antigenicity. Human dentin disks were treated with 0.5M of EDTA, citric acid, maleic acid, or phosphoric acid (for 15 or 30 s). A double-immunolabeling technique was performed to identify, simultaneously, collagen fibrils and chondroitin sulfate. The use of different acids resulted in different degrees of labeling. Maleic and citric acids revealed a diffuse and intense labeling for both collagen fibrils and proteoglycans. The use of phosphoric acid on dentin showed a massive coagulation of the proteoglycans (15 s) or very low labeling (30 s). These data clarify that the use of acids on dentin components is able to modify their antigenicity. Moreover, the double-labeling immunocytochemical technique allows understanding of the spatial relationships between the collagen fibrils and proteoglycans of the dentin matrix.

Functional recovery after surgical resection of low grade gliomas in eloquent brain: hypothesis of brain compensation

OBJECTIVES

To describe functional recovery after surgical resection of low grade gliomas (LGG) in eloquent brain areas, and discuss the mechanisms of compensation.

METHODS

Seventy-seven right-handed patients without deficit were operated on for a LGG invading primary and/or secondary sensorimotor and/or language areas, as shown anatomically by pre-operative MRI and intraoperatively by electrical brain stimulation and cortico-subcortical mapping.

RESULTS

Tumours involved 31 supplementary motor areas, 28 insulas, 8 primary somatosensory areas, 4 primary motor areas, 4 Broca's areas, and 2 left temporal language areas. All patients had immediate post-operative deficits. Recovery occurred within 3 months in all except four cases (definitive morbidity: 5%). Ninety-two percent of the lesions were either totally or extensively resected on post-operative MRI.

CONCLUSIONS

These findings suggest that spatio-temporal functional re-organisation is possible in peritumoural brain, and that the process is dynamic. The recruitment of compensatory areas with long term perilesional functional reshaping would explain why: before surgery, there is no clinical deficit despite the tumour growth in eloquent regions; immediately after surgery, the occurrence of a deficit, which could be due to the resection of invaded areas participating (but not essential) to the function; and why three months after surgery, almost complete recovery had occurred. This brain plasticity, which decreases the long term risk of surgical morbidity, may be used to extend the limits of surgery in eloquent areas.

Phase I-II study on isolation antiblastic fotemustine perfusion after dacarbazine chemosensitization for advanced melanoma of the extremities

Isolation limb perfusion (ILP) is the treatment of choice for locally advanced limb melanoma. With melphalan, the referral drug, complete response (CR) is achieved in about 50% of patients, but significant local toxicity occurs in up to 30%. The aim of the present phase I-II study was to challenge fotemustine (F) in ILP after systemic chemosensitization with dacarbazine (DTIC), given its lower toxicity and greater efficacy, as reported in a previous pilot study. Eleven patients with locally advanced limb melanoma were subdivided into triplets, and given F ILP at escalating doses (starting from 25 mg/l) after intravenous administration of 500 mg/m2 DTIC. Acute and chronic locoregional and systemic toxicity, tumour response and clinical outcome were evaluated. Two patients in the first triplet had G3-G4 local toxicity, so that the scheduled F dosage was halved. At drug levels of 12.5, 15.6 and 18.2 mg/l, local toxicity decreased, but only one of eight patients showed CR. The trial was then interrupted due to the low tolerability and poor efficacy of this perfusion regimen. At present, F ILP after DTIC chemosensitization should not be recommended for the treatment of locally advanced limb melanoma.