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At least 973 records · Page 54Linked to original sources
PubMed2005

The therapeutic value of adrenalectomy in case of solitary metastatic spread originating from primary renal cell cancer.

INTRODUCTION: Solitary adrenal metastases occur in about 1.2-10% of renal cell cancer patients. Since the vast majority of intraadrenal lesions can be detected preoperatively, we and others have recently recommended to renounce a routine adrenalectomy during surgery of renal cell cancer. However, the impact of adrenalectomy on the patients' clinical prognosis in case of a solitary metastatic lesion within the adrenal gland remains an issue of controversial discussion. Whereas some authors suggest adrenalectomy as a potentially curative treatment option in these cases, others compare its clinical value with that of a mere lymphadenectomy. PATIENTS AND METHOD: Between 1981 and 2000, 648 patients (440 males and 208 females) underwent nephrectomy in combination with adrenalectomy in our clinic for the diagnosis of renal cell cancer. The median age at first diagnosis was 59 (range 33-84) and 60 (range 20-85) years for male and female patients, respectively. The median postoperative follow - up was 2.4 years (0.2-18 years). According to the TNM - classification system (2003) tumor stages were classified as follows: T1, 228 pat. (37%); T2, 70 pat. (11%); T3, 287 pat. (46%); T4, 37 pat. (6%). In total, 339 patients revealed regional lymph node or distant metastases at the time of the surgical treatment. Although metastases of the adrenal gland were diagnosed in 48 patients, solitary intraadrenal metastases without further systemic spread were observed in only 13 cases. Several patients' and tumor characteristics (age, tumor stage and size, the presence of regional lymph node metastases, the presence of metastatic lesions at different organ sites as well as the detection of solitary intraadrenal metastases) were correlated with the patients' overall survival by univariate and multivariate statistical analysis (logistic Cox regression analysis). RESULTS: The median long - term survival was 4.8 years for the entire cohort of patients investigated. The median long - term survival was 13.8 years and 11.7 years for patients with no evidence of metastatic spread as well as for patients with a solitary intraadrenal metastatic lesion, respectively. Accordingly, the long - term survival rates at 5 and 10 years after surgery were 66%/50% and 51%/51% for patients with no evidence of metastatic spread or isolated intraadrenal metastases. This difference was not statistically significant. In contrast, for patients revealing lymph node or distant metastases at other organ sites, the median long - term survival was significantly decreased (lymph node metastases: 0.7 years; distant metastases: 1.2 years). DISCUSSION: For patients with a solitary intraadrenal metastatic lesion, adrenalectomy is a potentially curative treatment option. The observation that the long - term survival of the latter patients is comparable to that of patients with organ - confined disease might suggest the establishment of a separate TNM - category for patients revealing a solitary metastasis within the adrenal gland and no hint at further systemic metastatic spread.

Adrenal Gland Neoplasms↗
PubMed2006

Cooperation of isoforms of laminin-332 and tenascin-CL during early adhesion and spreading of immortalized human corneal epithelial cells.

The repair of corneal wounds requires both epithelial cell adhesion and migration. We have studied the early adhesion process of immortalized human corneal epithelial (HCE) cells and show by field emission scanning electron microscopy (FESEM) that the cells first adhere via foot-like process to the growth substratum and later present lamellar spreading. During early adhesion indirect immunofluorescence showed that the cells codeposited laminin (Lm) -332 and the large subunit of tenascin-C (Tn-CL) as a demarcated plaque beneath the cells. Instead, unprocessed Lm-332 (alpha 3'32) was found in a wider area in cells showing lamellar spreading and was also prominently expressed in the cytoplasm of the migrating marginal cells in the in vitro wounded HCE cultures. Confocal laser scanning microscopy (CLSM) showed that the Golgi apparatus was located to the vicinity of the Lm-332/Tn-CL-containing adhesion plaque and accordingly treatment of the cells with demecolcine, dispersing the Golgi apparatus, prevented the formation of plaques. This suggests that formation of the adhesion plaque depends on a direct vectorial secretion of Lm-332 and Tn-CL to the culture substratum. Instead, cytochalasin B treatment disrupted microfilaments and arborized the cells but did not affect the deposition of Tn-CL/Lm-332 as a plaque beneath the cells. The suggestion was supported by immunoprecipitation experiments which showed that Tn-CL and Lm alpha 3' chain were found in cell-free matrices on the culture substratum of spreading cells but not at all (Tn-CL) or much less (Lm-332) in the culture medium. Quantitative cell adhesion experiments showed that HCE cells did not adhere to plain Tn-C coat and that integrin (Int) alpha(3)beta(1) mediated the adhesion of HCE cells to purified Lm-332 and to Lm-332/Tn-C while Int beta4 did not mediate adhesion to these proteins. Taken together, our data suggest that Lm-332 and Tn-CL cooperate in early adhesion process of HCE cells. Furthermore, the results show that Lm-3'32 isoform functions in the spreading of the cells beyond the early adhesion stage and appears to emerge into HCE cells starting to migrate in experimental wounds.

Cell Adhesion↗
PubMed2005

Modification of lupus-associated 60-kDa Ro protein with the lipid oxidation product 4-hydroxy-2-nonenal increases antigenicity and facilitates epitope spreading.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with autoantibodies as a near universal feature of the disease. The Ro ribonucleoprotein particle, composed of a 60-kDa protein noncovalently associated with human cytoplasmic RNA, is the target of antibodies in 25-40% of lupus patients. Purified human 60-kDa Ro was found to be oxidatively modified. Earlier investigations from our laboratory revealed increased oxidative damage in SLE patients. Therefore we hypothesized that oxidation by-products, such as 4-hydroxy-2-nonenal (HNE), could lead to neoantigens like HNE-modified 60-kDa Ro, which could in turn initiate autoimmunity or drive epitope spreading. To test this hypothesis we immunized rabbits with either HNE-modified 60-kDa Ro or the unmodified Ro. Intramolecular epitope spreading within the Ro molecule and intermolecular epitope spreading to La, double-stranded DNA, nRNP, and Sm occurred preferentially in HNE-Ro-immunized animals. Nonspecific anti-HNE antibody, generated by immunization with HNE-keyhole limpet hemocyanin conjugate, did not significantly bind to these autoantigens. These data may suggest a hitherto unappreciated mechanism by which oxidative stress facilitates epitope spreading in SLE.

Aldehydes↗
PubMed2005

Infection of naïve, free-living brushtail possums (Trichosurus vulpecula) with the nematode parasite Parastrongyloides trichosuri and its subsequent spread.

Despite the importance of spatial processes in host-parasite interactions, parasite dispersal has been the subject of few experimental studies. Introduced marsupial common brushtail possums (Trichosurus vulpecula) are a major environmental and agricultural pest in New Zealand. Parastrongyloides trichosuri, an intestinal rhabdiasoid nematode parasite specific to possums, is being evaluated as a self-disseminating delivery system for engineered fertility control vaccines. This study addressed whether an artificial infection could be established in a naïve, free-living possum population, by measuring the post-release dynamics of possum-parasite interactions at the release site, and by following the spread of the parasite into surrounding possum populations. Infection was established efficiently by applying infective larvae to the skin of possums on a single occasion. All experimentally infected possums recaptured 3 weeks after infection had parasite eggs in their faeces. Over the subsequent 2.5 years, infection spread steadily over an area of about 6000 ha. Infection persisted at the original release site for the 3.5 years of the study and at a nearby site infected by natural spread for more than 3 years. Seasonal changes in faecal egg counts were similar at the two sites. The rapid establishment of the parasite and its spread provide additional support for its ongoing development as a vaccine delivery system.

Animals↗
PubMed2006

Evidence for direct transfer of cytoplasmic material from infected to uninfected cells during cell-associated spread of human cytomegalovirus.

Cell-associated spread is assumed to be the predominant mode of human cytomegalovirus (HCMV) dissemination in infected patients, however the underlying mechanisms are poorly understood. We tested the hypothesis that cell-to-cell spread of HCMV may be associated with direct transfer of cytoplasmic material by analyzing focal growth of green fluorescent HCMVDeltaUL16GFP. In this recombinant virus, UL16 was partially replaced by the green fluorescent protein (EGFP). The resulting HCMVDeltaUL16GFP showed unrestricted growth and expressed EGFP from the early UL16 promoter. EGFP transmission was then investigated in relation to viral spread from productively infected cells to cocultured uninfected cells. Alternatively, microinjection of fluorescent dextrane allowed for direct visualization of inter-cell-connections. Within 5h of coculture, 8% of cells neighbouring productively infected cells had acquired EGFP. Detection of EGFP in the absence of IE antigen and during cycloheximide block excluded the possibility of de novo synthesis. Immediate distribution of microinjected fluorescent dyes from infected cells to adjacent cells proved the existence of cell-cell-fusions. These data demonstrate that focal spread of HCMV is associated with direct transfer of cytoplasmic material, most likely through cell-cell-fusions. This would withdraw the virus from the control of neutralizing antibodies and thus provide an explanation for the limited antiviral effect of the humoral immune response.

Cell Fusion↗
PubMed2006

Modeling the release, spreading, and burning of LNG, LPG, and gasoline on water.

Current interest in the shipment of liquefied natural gas (LNG) has renewed the debate about the safety of shipping large volumes of flammable fuels. The size of a spreading pool following a release of LNG from an LNG tank ship has been the subject of numerous papers and studies dating back to the mid-1970s. Several papers have presented idealized views of how the LNG would be released and spread across a quiescent water surface. There is a considerable amount of publicly available material describing these idealized releases, but little discussion of how other flammable fuels would behave if released from similar sized ships. The purpose of this paper is to determine whether the models currently available from the United States Federal Energy Regulatory Commission (FERC) can be used to simulate the release, spreading, vaporization, and pool fire impacts for materials other than LNG, and if so, identify which material-specific parameters are required. The review of the basic equations and principles in FERC's LNG release, spreading, and burning models did not reveal a critical fault that would prevent their use in evaluating the consequences of other flammable fluid releases. With the correct physical data, the models can be used with the same level of confidence for materials such as LPG and gasoline as they are for LNG.

Accidents↗
PubMed2004

Involvement of lymphatic metastatic spread in non-small cell lung cancer accordingly to the primary cancer location.

OBJECTIVES: The purpose of the study is to investigate the contribution of lymphatic spread in operable non-small cell lung cancer (NSCLC) in relation to the cancer location. METHODS: We retrospectively studied 557 consecutive patients [514 males and 43 females, mean age 62.5 +/- 9.1 years (range, 20-84)] who underwent a major lung resection due to NSCLC in our department, from January 1995 to December 1999. Preoperative staging for metastatic disease was negative. Extended mediastinal lymph node dissection was performed in all lung resections. RESULTS: The pathology report revealed 220 adenocarcinomas, 276 squamous-cell, 34 undifferentiated, 25 adenosquamous and 2 large-cell carcinomas. The TNM stage was IA in 52 patients, IB in 109, IIA in 20, IIB in 146, IIIA in 190, IIIB in 35 and IV in 5. The classification of disease was N0 in 240 (40.1%) patients, N1 in 179 (32.1%) and N2 in 138 (24.8%). Twenty-eight patients (5.03%) presented a skip metastasis to hilar lymph nodes, while 27 patients (4.85%) presented with skip metastasis to the mediastinum. The size of the primary tumors presenting with metastases was significantly smaller in adenocarcinomas compared to squamous-cell carcinomas (P = 0.046). Regarding the right lung, tumors originating in the upper lobe mainly metastasized to level No. 4, while tumors of the middle lobe spread to stations Nos. 4 and 7, and those in the lower lobe to level No. 7. Regarding the left lung, tumors originating in the upper lobe metastasized to level No. 5, while tumors within the lower lobe spread to stations, Nos. 7-9. CONCLUSIONS: Mediastinal lymph nodal dissection is necessary for the accurate determination of pTNM stage. It seems that there is no definite way for lymphatic spreading in relation to the location of the cancer. Skip metastasis to the mediastinal lymph nodes was present in 4.85% of our patients, while adenocarcinomas, even small-sized ones, are more aggressive than squamous-cell carcinomas.

Adult↗
PubMedDate not supplied

A nested-epidemic model for the spread of hepatitis C among injecting drug users.

Injecting drug users (IDUs) are the largest risk group for HCV infection. Studying injecting by classical epidemiological methods is no easy task, largely due to its hidden nature and low prevalence in general population terms. Thus, mathematical modelling can be of major help in performing a qualitative and quantitative evaluation of the costs and possible impact of the various interventions and to produce forecasts of both injecting drug use and HCV spread among IDUs. In the present paper an epidemic Mover-Stayer model for the spread of drug use, which has been recently proposed, is extended to mirror the spread of an infectious disease, in particular hepatitis C, among the injecting drug user population. In order to model the spread of a disease (HCV) among a population evolving following a different epidemic (injecting drug use) all the compartments of the 'external epidemic' (injecting drug use) are subdivided into two sub-compartments: the first one comprising individuals who are not affected by HCV and the second one comprising individuals affected. The resulting model may be defined the 'two epidemics' or, better, the 'nested epidemics' model. The model is a Mover-Stayer model for what concerns the 'external epidemic' (injecting drug use) but is a homogeneous epidemic model for HCV (all individuals are at risk of HCV the same). In the following, the dynamic equations are derived. Some qualitative analysis is performed in order to evaluate the asymptotic behaviour and the impact of possible prevention or harm reduction interventions. The results of a scenario analysis are also presented. The model, though simple, seems to be a very valuable tool for policy makers.

Disease Outbreaks↗
PubMed2004

A model of the spread of the bovine viral-diarrhoea virus within a dairy herd.

Wet BVDSim (a stochastic simulation model) was developed to study the dynamics of the spread of the bovine viral-diarrhoea virus (BVDV) within a dairy herd. This model took into account herd-management factors (common in several countries), which influence BVDV spread. BVDSim was designed as a discrete-entity and discrete-event simulation model. It relied on two processes defined at the individual-animal level, with interactions. The first process was a semi-Markov process and modelled the herd structure and dynamics (demography, herd management). The second process was a Markov process and modelled horizontal and vertical virus transmission. Because the horizontal transmission occurs by contacts (nose-to-nose) and indirectly, transmission varied with the separation of animals into subgroups. Vertical transmission resulted in birth of persistently infected (PI) calves. Other possible consequences of a BVDV infection during the pregnancy period were considered (pregnancy loss, immunity of calves). The outcomes of infection were modelled according to the stage of pregnancy at time of infection. BVDV pregnancy loss was followed either by culling or by a new artificial insemination depending on the modelled farmer's decision. Consistency of the herd dynamics in the absence of any BVDV infection was verified. To explore the model behaviour, the virus spread was simulated over 10 years after the introduction of a near-calving PI heifer into a susceptible 38 cow herd. Different dynamics of the virus spread were simulated, from early clearance to persistence of the virus 10 years after its introduction. Sensitivity of the model to the uncertainty on transmission coefficient was analysed. Qualitative validation consisted in comparing the bulk-milk ELISA results over time in a sample of herds detected with a new infection with the ones derived from simulations.

Animals↗
PubMedDate not supplied

Locating the target nerve and injectate spread in rabbit sciatic nerve block.

BACKGROUND AND OBJECTIVES: The purpose of this study is to determine how close the needle tip is placed to the target nerve using a nerve stimulator and to determine how far the injectate spreads in percutaneous nerve blocks. METHODS: Twenty-four sciatic nerves of New Zealand white rabbits were located with a 2-dimensional needle manipulator and a nerve stimulator (pulse width: 100 micros for group I, 250 micros for group II). The stimulation current required to elicit a motor response for each insertion depth of the needle and the nerve-needle distance at which the required current reached the minimum were measured. Another 10 sciatic nerves were located manually using a nerve stimulator and neurolyzed with a mixed solution of 5% phenol and Indian ink (100 microL). RESULTS: The nerve-needle distance was in the range of -1.2 mm to +2.8 mm in group I (1.1 +/- 0.9 mm [mean +/- standard error] in absolute value) and -0.2 mm to +4.8 mm (2.2 +/- 1.7 mm [mean +/- standard error] in absolute value) in group II (positive values signify the center of the beveled surface is past the nerve), when the stimulation current reached the minimum (average minimum current: 0.47 mA in group I, 0.37 mA in group II). Indian ink spread over a significant distance (25.4 +/- 0.5 mm [mean +/- standard error]; range, 19-31 mm) longitudinally within the perineural tissue, and axonal degeneration was observed linearly at the peripheral portion of the nerve fascicle in a similar pattern as Indian ink spread. CONCLUSIONS: The target nerve was located within 5 mm from the needle with less than 0.5-mA stimulation current. The injectate spread to more than 20 mm on average even when a small volume (100 microL) of the injectate was injected in rabbit sciatic nerves.

Animals↗
PubMed2006

Differential localization of unconventional myosin I and nonmuscle myosin II during B cell spreading.

Cross-linking of CD44 in vitro promotes chemokinesis and actin-based dendrite formation in T and B cells. However, the mechanisms by which the adhesion molecule CD44 induces cytoskeleton activation in lymphocytes are still poorly understood. In this study, we have investigated whether myosin isoforms are involved in CD44-dependent dendrite formation in activated B cells. Pharmacological inhibition of myosin with 2,3-butanedione monoxime strongly affected spreading and dendrite formation, suggesting that these cellular motors may participate in these phenomena. Furthermore, immunofluorescence analysis showed differences in subcellular localization of class I and class II myosin during B cell spreading. In response to CD44 cross-linking, myosin-1c was polarized to lamellipodia, where F-actin was high. In contrast, the distribution of cytosplasmic nonmuscle class II myosin was not altered. Expressions of myosin-1c and II were also demonstrated in B cells by Western blot. Although the inhibition of PLCgamma, PI3K and MEK-1 activation affected the spreading and dendrite formation in activated B cells, only PLCgamma and MEK-1 inhibition correlated with absence of myosin-1c polarization. Additionally, myosin-1c polarization was observed upon cross-linking of other surface molecules, suggesting a common mechanism for B cell spreading. This work shows that class I and class II myosin are expressed in B cells, are differentially distributed, and may participate in the morphological changes of these cells.

Actins↗
PubMed2005

Endometrial carcinosarcomas have a different prognosis and pattern of spread compared to high-risk epithelial endometrial cancer.

OBJECTIVE: The endometrial origin of uterine carcinosarcoma has recently been well established. The current study investigates whether uterine carcinosarcomas can be included in protocols on high-risk endometrial cancer, given the similarities in biologic behavior of both entities. METHODS: Pathological and surgical notes of patients diagnosed with grade 3 endometrioid, carcinosarcoma, serous and clear cell endometrial cancer subtypes were retrospectively analyzed with special attention to the spread pattern of the different subtypes. Information on site of relapse and time to recurrence was obtained. RESULTS: We traced 146 patients of which 9 patients were ineligible. Histological subtypes of the remaining 137 patients were as follows: 50 (37%) grade 3 endometrioid carcinoma, 54 (39%) serous or clear cell carcinoma (non-endometrioid carcinoma), and 33 (24%) carcinosarcomas. Distribution of early stage disease (I and II) was 67, 46, and 78% for grade 3 endometrioid, non-endometrioid, and carcinosarcoma, respectively. Although we could not trace differences in hematogenic and transperitoneal spread among the three subtypes, non-endometrioid and carcinosarcomas were more likely to spread to pelvic and paraaortic lymph nodes (P < 0.01). Using univariate analysis, both stage (P < 0.006, Wald statistic) and histological type appear to determine the outcome, whereas lymphovascular space infiltration (P < 0.25) and age (P < 0.07) were not significantly different between the three histological subtypes. Cox Regression multivariate analysis on 127 women suffering from the three histological subtypes suggested that both stage III-IV disease (P < 0.00001) and histological type (carcinosarcoma) (P < 0.003) were of prognostic significance [hazard ratio (CI 95%) were, respectively, 3.8 (2.1-7.0) and 3.2 (1.7-5.9)]. Analyzing cases limited to stage I-II endometrial cancer, 24/28 (86%) grade 3 endometrioid, 18/24 (75%) non-endometrioid, and 11/25 (44%) carcinosarcomas survived, suggesting a worse outcome for endometrial carcinosarcoma when compared to the other subtypes (P < 0.008, Log Rank). A higher incidence of pulmonary metastases explained the worse outcome for early stage carcinosarcoma (P < 0.006), whereas the incidence of liver metastasis, transperitoneal spread, or recurrences in lymph nodes or vagina were comparable between the three pathologic subtypes. CONCLUSIONS: Although endometrial carcinosarcoma originates from epithelial cancer, the intrinsic more aggressive tumor biology suggests that this subtype should not be incorporated in studies on high-risk epithelial endometrial cancer.

Adenocarcinoma, Clear Cell↗
PubMed1996

The mode of lymphatic spread in carcinoma of the bile duct.

BACKGROUND: Knowing the prevalence of lymph node involvement associated with the location of the primary tumor is a prerequisite for operating with curative intent in carcinoma of the bile duct. METHODS: We evaluated 80 patients with carcinoma of the bile duct or cystic duct to investigate the frequency of lymph node involvement, the mode of lymphatic spread, and prognosis, according to the location of the primary tumor. RESULTS: The frequency of lymphatic spread of carcinomas in the proximal, middle, and distal bile ducts, excluding seven T1 tumors, was 48%, 67%, and 56%, respectively. With regard to the mode of lymphatic spread: (1) a metastatic pathway along the common hepatic artery predominated over that to the retropancreatic area in the proximal duct carcinoma group; (2) in the middle duct carcinoma group, metastatic lymph nodes were distributed widely, involving nodes around the superior mesenteric artery or at the para-aortic area; and (3) in the distal duct carcinoma group, metastatic nodes generally were localized around the head of the pancreas. CONCLUSIONS: Understanding the mode of the lymphatic spread according to the primary tumor may be helpful for choosing the appropriate surgical approach with curative intent in bile duct carcinoma.

Adult↗
PubMed1998

Clinicopathological analysis of local spread of carcinoma of the tongue.

BACKGROUND: The aims of the study are three-dimensional analysis of mode and distance of local spread of oral tongue carcinoma. METHODS: The glossectomy specimens were examined in the coronal plane in 3 mm thickness section. RESULTS: There were 50 glossectomy specimens. The maximum spread was 1.8 cm. Ninety-six percent of specimens had local spread within 1.2 cm. The distance of spread was not correlated with tumor size, including the diameter, depth, and volume. The incidence of local recurrence was 27% with positive histological margin. Perineural infiltration was the most important prognostic factor for local recurrence and survival. CONCLUSIONS: A minimum of 1.5-cm surgical resection margin is recommended. A smaller margin is not recommended as it has significant risk of local recurrence. A maximum of 2-cm surgical resection margin is recommended; larger margins will increase the surgical morbidity without a significant advantage of local control.

Adolescent↗
PubMed1997

The triggering of spreading depression in the chick retina by nicotinic receptor agonists.

Spreading depression was evoked in vitro in retinas of 3-6 day old chickens by the nicotinic cholinergic agonists nicotine and cytisine. The response was reproducible and inhibited by the nicotinic cholinergic receptor antagonist mecamylamine and by the NMDA receptor antagonist -3-(2 carboxypiperazine-4-yl)-propyl-1-phosphonic acid (CPP). The response to nicotinic agonists was not inhibited by alpha-bungarotoxin. The data show that spreading depression can be evoked in the chick retina by alpha-bungarotoxin insensitive nicotinic acetylcholine receptor subtypes and that the response is dependent upon NMDA receptor activation. This nicotine evoked spreading depression was inhibited by cadmium chloride indicating the involvement of voltage sensitive calcium channels. It is therefore argued that nicotine evokes spreading depression indirectly, as a result of calcium sensitive glutamate release. The glutamate released thus exerting its effects via NMDA receptors.

Animals↗
PubMed2001

Transpapillary intraductal US prior to biliary drainage in the assessment of longitudinal spread of extrahepatic bile duct carcinoma.

BACKGROUND: The utility of intraductal US via the transpapillary route prior to biliary drainage in the assessment of longitudinal extension of extrahepatic bile duct carcinoma was investigated. METHODS: In 19 patients with extrahepatic bile duct carcinoma who underwent surgical resection, an ultrasonic probe (diameter, 2.0 mm; frequency, 20 MHz) was inserted into the bile duct via the transpapillary route prior to biliary drainage. Longitudinal cancer extension along the bile duct was prospectively determined and compared with the histologic findings in the resected specimens. RESULTS: Results on the hepatic side were as follows: Intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 9 of 19 patients with one instance of overdiagnosis. The accuracy of intraductal US in assessing the extent of spread (84%) was superior to that of cholangiography (47%) (p < 0.05). Results on the duodenal side were as follows: In patients with suprapancreatic bile duct cancer (n = 14), intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 8 of 14 patients. The accuracy of intraductal US in assessing the extent of the spread (86%) was superior to that of cholangiography (43%) (p < 0.05). CONCLUSIONS: Transpapillary intraductal US prior to biliary drainage is useful in demonstrating longitudinal extension of bile duct cancer. However, the surgical margins were inaccurate in some patients.

Aged↗
PubMed2003

Retardation of water evaporation by less-defective mixed monolayers spread from bulk solids onto water surface.

From AFM observation of transferred films on mica, it has been found that mixed monolayers of hexadecanol with poly(vinyl stearate) give a film with a less-defective and flat surface by spreading from bulk solids of those mixtures onto a water surface without using any organic solvent. As a result, those mixed monolayers have a considerably larger effect on retardation of water evaporation in comparison with those spread from the solution of the mixtures. After the saturated surface pressure of the mixed monolayer spread from the bulk solids, an enhanced effect on retardation of water evaporation was found, accompanied by the preferential spreading of hexadecanol and the gradual reduction of defects in the mixed monolayer.

Journal Article↗
PubMed2000

The spread of attention and learning in feature search: effects of target distribution and task difficulty.

We examined the roles of two determinants of spatial attention in governing the spread of perceptual learning, namely, stimulus location distribution and task difficulty. Subjects were trained on detection of a target element with an odd orientation imbedded in an array of light bars with otherwise uniform orientation. To assess the effects of target distribution on attention and learning, target positions were distributed so that attention was allocated not only to the target positions themselves, but also to intermediate positions where the target was not presented. Target detection performance substantially improved and improvement spread to match the induced window of spatial attention rather than only the actual target locations. To assess the effect of task difficulty on the spread of attention and learning, the target-distractor orientation difference and the time interval available for processing were manipulated. In addition, we compared performance of subjects with more versus with less detection difficulty. A consistent pattern emerged: When the task becomes more difficult, the window of attention shrinks, and learning becomes more localized. We conclude that task-specific spatial attention is both necessary and sufficient to induce learning. The spread of spatial attention, and thus of learning, is determined by the integrated effects of target distribution and task difficulty. We propose a theoretical framework whereby these factors combine to determine the cortical level of the focus of attention, which in turn enables learning modifications.

Adult↗