彩色多普勒内镜超声在胰岛细胞瘤术前定位诊断中的作用

目的 探讨彩色内镜超声在胰岛细胞瘤术前定位诊断中的作用。方法 对经内科检查定性诊断为胰岛细胞瘤，并准备手术切除的7例患者，术前进行彩色多普勒内镜超声（ECDUS），经腹B超和胰腺螺旋CT增强扫描检查，并与手术和病理检查结果相对照，比较上述3种影像学检查在术前定位诊断中的作用。结果 7例患者手术和病理检查共发现10个病灶，ECDUS检出8个，胰腺螺旋CT增强扫描检出1个，经腹B超未有检出，病灶部位与手术见一致。ECDUS漏诊的2个病灶，直径均小于或等于0.5cm。检查中无并发症发生。结论 ECDUS对胰岛细胞瘤的术前定位诊断比B超，CT等无创性检查技术，敏感性高，定位准确，但对于直径小于或等于0.5cm的病灶，定位诊断仍有困难。     

Richer color vocabulary is associated with better color memory but not color perception

The potential interaction between color naming and psychophysical color recognition has been historically debated. To study this interaction, here we utilized two approaches based on individual differences in color naming and variation of color name density along the color wheel. We tested a pool of Persian speaking subjects with a simple color matching task under two conditions: perceptual and memory-based matching. We also asked subjects to freely name 100 evenly sampled hues along the color wheel. We found that, individuals who possess more names to describe the color wheel have a strong edge in color memorization over those with fewer names. Nevertheless, having more or fewer color names was not related to the subjects’ performance in perceptual color matching. We also calculated the density of color names along the color wheel and observed that parts of the color wheel with higher density of color names are held in memory more accurately. However, similar to the case of individual differences, the density of color names along the wheel did not show any correlation with perceptual color matching performance. Our results demonstrate a strong link between color naming and color memorization both across different individuals and different parts of the color wheel. These results also show that low-level perceptual color matching is not related to color naming, suggesting that the variation in color naming—among the individuals and across the color wheel—is neither the cause nor the effect of variation in low-level color perception.

Humans break the color wheel into smaller segments, each labeled by a color name. Some individuals employ more names to segment the color wheel and some, less sophisticated with naming, use fewer labels to describe it. Do individuals who possess more color names have better color vision? For nearly half a century, considerable debates have been raised over this simple question. On one hand, the “universalist view” suggests that the mental process of color recognition is independent of the linguistic processes that assign names to colors. According to this view, the linguistic color pallet, the vocabulary treasure that discriminates various hues in a language, does not constrain the way humans perceive and remember colors (1, 2). On the other hand, the “relativist view” implies that assignment of color names to various parts of the color wheel interacts with color recognition performance in humans (3–10).To address the debate between universalist and relativist views, one should experimentally address a “problem of circularity” formalized by Winawer and Witthoft (11). The problem of circularity arises from an inherent problem in the definition of “spacing” in any color space. In order to psychophysically measure the potential effect of linguistic category boundaries on color recognition for different colors (within or between category boundaries), the experimenter first needs to create a physically controlled and evenly spaced color space. Now, if linguistic color categories are taken into account for equal spacing of test colors, then by definition there won’t be any residual linguistic effects left to measure; if not, how can one ensure the test colors were equally spaced to begin with? In the latter case, any observed category effect may reflect the possibility that colors within a linguistic category are psychophysically harder to discriminate and that’s why they have fallen into a natural category in the first place. Winawer and Witthoft have listed three categories of psychophysical approaches to break the circularity problem and investigate the potential relationship between language and color vision: cross-linguistic studies, hemifield specific effects, and verbal interference experiments.Historically most of the fuel for the debate between universalist and relativist camps come from cross-linguistic studies. In this approach, variation of linguistic color pallet across different languages is used to explain the variation in color recognition performance among the speakers of those languages (e.g., refs. 1, 2, 5, 7–10). In this way the circularity problem is bypassed because the physical spacing of test colors can be kept constant while linguistic category boundaries vary across different languages. Some cross-linguistic studies have revealed interesting effects of language on color memory and learning (e.g., refs. 5, 6, 9), thus supporting the relativist view. Nevertheless, other studies have supported the universalist view (e.g., refs. 1, 2). As informative as cross-linguistic studies are, they come with an inherent problem; cross-cultural confounding factors. Distance from the equator that determines the amount of ultraviolet (UV) damage to the eyes (12), variations in advancement and application of color display technology (13), and cultural variation in exposure to colorful materials (14) are among the many variables that affect color recognition performance and may vary across cultures besides the variation in language. In addition, other sources of variance such as individual differences in color recognition may contaminate cross-linguistic measures of color recognition performance (15). These sources of variance may conceal potential effects of language on color recognition and explain some of the discrepancies in the literature.Another category of psychophysical studies that concern language and color vision has emerged based on the neurophysiological fact that in most people, language is mostly processed by the left hemisphere (16–18). This leads to the assumption that visual stimuli that are presented to the left hemisphere (right visual field) are influenced more by language. This assumption addresses the circularity problem by keeping the physical spacing of colors constant, yet varying the linguistic effects by varying the visual field. These experiments are done in the context of a single language (19, 20) as well as in combination with cross-linguistic studies (21). The latter case is quite interesting because it controls for potential cross-linguistic confounding factors. In some cases, this category of experiments has revealed effects of linguistic category boundaries on color recognition in the context of speeded visual search task (e.g., refs. 19–21). However, other studies have failed to replicate some of those results and the source of discrepancy is still debated (22, 23).The third category of evidence comes from verbal interference experiments. The idea behind this class of studies is that if color vision depends on language, it should be affected by the conditions in which language faculty is overloaded by a parallel task (6, 7, 10, 19). The problem of circularity is addressed here by keeping the spacing between colors physically constant, and varying the involvement of the language faculty in the task. These experiments are done both for a single language (e.g., refs. 6, 19) and in the context of cross-linguistic studies (e.g., refs. 3, 7, 10). Verbal interference experiments generally support the relativist view as they reveal various effects of verbal interference on color visual search (19), speeded color matching reaction times (7, 10), color memory (6), and oddball color detection (3). The problem with verbal interference experiments is rather a pragmatic one. Given the difficulty of performing interference experiments for human subjects, the number of verbal interference trials that can be collected from each subject is small and practically limited to the median of 96 trials (ranged from 432 to 16) in the previous studies (e.g., refs. 6, 7, 10, 19). Because of this limitation, the entire body of evidence in this category comes from a carefully selected but limited set of colors around specific linguistic category boundaries such as the blue/green (e.g., refs. 3, 6, 19, 24) blue/dark-blue (e.g., refs. 7, 10) boundaries and multiple (seven) preselected category boundaries (25). The generality of these findings for the entire color wheel is yet to be studied. Building on this rich history, here we introduce two approaches in order to eliminate some of the limitations of previous studies and to investigate the interaction of language with color recognition more directly. In the first approach, in order to avoid cross-cultural confounding factors, we utilized individual differences in color naming and color recognition within only one linguistic domain. There are individual differences in color naming and color recognition even within a language domain (9, 26, 27); we harnessed this natural variance in order to study the covariance of color naming and color recognition in a pool of Persian speaking subjects. Here, to break the problem of circularity, we kept the physical colors constant and varied the observer within a cultural domain.In the second approach, unlike many previous studies that were limited only to specific color category boundaries, here we measured the subjects’ color naming and color recognition performance for the entire color wheel in a parameterized way. Then, we used heterogeneity of distribution of color names and color recognition performance along the color wheel as a source of variance to study their relationship. In this approach, instead of trying to neutralize the problem of circularity, we directly measured its effects on a physically constant set of colors in the context of two different psychophysical tasks; perceptual and memory-based matching (Discussion). The analytical methods developed here are language independent, thus they can be replicated and compared for any other language domain in the future.To measure color recognition performance we adopted two separate operational definitions of “color recognition”: a simple low-level color matching task to directly assess concurrent color perception of the subjects, as well as a color memory task. Using these two tasks we aimed at two empirical questions: 1) Is color perception and color memory performance different among individuals with different vocabulary treasure of color names? 2) Independent of individual differences, does the distribution of color names along the color wheel predict color recognition performance for different hues?To achieve these aims, we tested color recognition abilities of the subjects using a color matching paradigm. In each trial, the subjects were required to change the color of a “test patch” on the screen to match it with that of a “reference patch.” The reference patch was filled randomly with one of the 100 hues evenly sampled from an imaginary circle in the CIEIUV color space (Methods). There were two conditions for this task: the “perceptual matching” condition and the “memory-based matching” condition. In the perceptual matching condition, a test patch and a reference patch were presented simultaneously and the subjects could look at the reference patch as they made their match. This task aimed at documenting the most basic color recognition abilities of the subjects. In the memory-based matching condition, the reference patch was shown for 10 s, then it disappeared; following a delay of 10 s the test patch was presented to the subjects who matched its color to their memory of the reference patch. This task is tailored to measure color memory performance for each sampled hue separately (Fig. 1).Open in a separate windowFig. 1.(A) Stimuli. One hundred hue samples were selected evenly from the perimeter of an imaginary circle (r = 0.08) centered at gray in CIELUV color space. The color wheel on the Right side of the panel shows the sampled hues, U and V values varied among the 100 sampled colors but the luminance level was kept constant at 1 cd/m². (B) Color matching experiment in two conditions: perceptual matching and memory-based matching. Participants used a computer screen to match the color of 100 hue samples (presented in random order) under two conditions. In perceptual matching condition (Top) two patches of color were presented simultaneously on a black background. In each trial, one of the 100 sample colors, randomly selected, was presented in the top color patch (reference patch). The participants adjusted the color of the bottom patch (test patch) to match it with the reference patch. For each trial, the participants had 60 s to complete the matching procedure. Memory-based matching (Bottom) was similar to perceptual matching except for a 10-s delay introduced between the reference and test patches. In this condition, the participants were asked to withhold the color of the reference patch in memory and adjust the color of the test patch to match the memorized hue (see text for details). (C) Color matching results in a typical subject. The radius of each data point shows the average error of the matches for the 100 color samples. The blue line corresponds to perceptual matching and the red line represents memory-based matching.To determine the linguistic color pallet of each subject for the sampled color wheel, all of the subjects participated in a separate color naming task (Fig. 2A). The color naming task was presented to subjects after they completed the other two tasks; this was done to avoid potential biases in subjects’ performance in the two other tasks by informing them about our interest in language. In the color naming task the subjects were presented with all 100 sampled hues, one at a time in random order, and asked to type the name of the hue in a dialogue box. At first glance we measured the total number of names that each subject possesses to describe the entire perimeter of the sampled color wheel. The linguistic color pallets of our 20 subjects contained 21 to 50 unique names (mean = 38.80, SD = 7.709) for the tested colors. Female and male subjects possessed an average of 36.14 (median = 38) and 40.23 (median = 41) total color names, respectively. The effect of gender on the number of color names was not significant (t test, t (18) = 1.14, P = 0.2692). Then we investigated the relationship between subjects’ performance in the color matching task and the total name count on their color pallets. The distance between the reference hue and matched hue was defined as “error” for each match. For each subject, this error was averaged across all trials. We noticed a strikingly strong correlation between error and total color name count across subjects for memory-based color matching (r = −0.9428, P < 0.00001); the more color names you possess the better your color memory is (Fig. 2B). However, the clear advantage of people with more color names in the color memory task cannot be the result of their better color perception, simply because there was no correlation between error and total color name count for the perceptual color matching condition (r = −0.1462, P = 0.53).Open in a separate windowFig. 2.The more names an individual uses to describe colors the better her/his performance is on a color memory matching test. (A) Color naming task. All of the 100 sampled hues were presented to the subjects in random order in separate trials. In each trial, subjects were asked to type the name of the presented color into a text box on the screen (in Persian). (B) The abscissa indicates the number of unique names that each subject has to describe the color wheel. The ordinate represents the error (average of 20 subjects) of the participants on the color matching experiment. Each data point represents one of the 20 participants. While individuals who possess more names to describe the color wheel are similar to others in color perception, they can memorize colors more accurately. Left and Right, respectively, represent perceptual (r = −0.146, P = 0.538) and memory-based (r = −0.942, P < 0.0001) matching conditions. Upper subpanels depict color naming schema of two of the subjects (the ones who had the least and most color names). Each sector on the color wheel corresponds to a unique name that the subject uses to describe that part of the wheel.Did the subjects explicitly memorize the names of colors to perform the memory-based color matching task? Such an internal naming strategy may have helped the subjects who possess more color names in the memory-based task, thus it can explain the strong correlation observed. In order to assess the potential role of internal color naming in the subjects’ strategy for performing the color memorization task, in an exit interview we asked the participants to describe the strategy they used to remember different colors. Eight of the 20 participants (40%) reported that they memorized the exact test hues and not their names. For this group of subjects correlation between the size of color vocabulary and memory error was high and significant (r = −0.9620, P = 0.0001). The remaining 12 subjects (60%) reported that they matched the colors by memorizing both the hues and the hue labels. A similar near perfect correlation was observed for this group (r = −0.9538, P = 0). Fisher Z test shows no significant difference between these two correlation values (z = −0.2, P = 0.41). This suggests that the link between language and color memory is as strong for those subjects who “consciously and explicitly” think they have not used internal naming to perform the task (SI Appendix, Fig. S1). It is still possible that those subjects used some form of linguistic labeling without being consciously aware of it; we do not intend to reject this theoretical possibility and we leave its further exploration to future studies. In fact, if a form of implicit linguistic labeling mechanism exists, we would classify it as a natural mechanism for color memorization, given that we provided no instructions for performing our task. In any case, here, we only conclude that explicit usage of internal naming for performing memory-based color matching does not affect the correlation between color memory and color vocabulary size.Next, we aimed at our second empirical question: Is the distribution of color names along the wheel related to color recognition performance for various hues? To create a quantitative and language-independent measure of the distribution of color names we defined “name density.” Name density is the number of unique names that subjects possess to describe a small section of the color wheel. To measure name density for all hues, a sliding window (±5 hues from each sampled hue) was moved along the 100 sampled hues for each subject and the number of unique color names in each window (11 hues wide) was counted. As a result, a name densitogram was created for each subject. The name densitogram indicates the number of unique names that each subject has for each part of the tested color wheel (Fig. 3A).Open in a separate windowFig. 3.Variation of color name density and color matching performance along the color wheel. (A) Name densitogram. Name density (ND) was defined as the number of names that an individual assigned to each subsection of the color spectrum. The name densitogram shows the density of unique names at each point on the tested color spectrum for each individual (see text for details). (B) Interaction of name density and performance in color matching experiment. Black line indicates ND. Blue and red lines show error (average of 20 subjects) of the matches for the 100 tested hues in perceptual and memory-based matching, respectively. Vertical and horizontal axis labels correspond to error and name density, respectively.First, we noticed that name density varies significantly in different parts of the color wheel. In general, Persian speaking subjects have fewer names for orange (mean = 2.8) and purple (mean = 3.38) tones and more names for pink (mean = 6.8), and blue (mean: 4.7) and light green (mean = 5.12) shades. Among the pool of subjects one-way ANOVA showed a significant effect of hue on name density for all subjects (F (19,99) = 26.30, P < 0.000001). Analysis of data from individual subjects showed a significant negative correlation between name density and color matching error (across all hues) for the memory-based matching task in 16 out of 20 subjects. The distribution of Pearson r values among subjects was significantly below zero for memory-based matching (mean r = −0.321, SD = 0.189, t test: t (19) = −7.59, P < 0.00001). Name density and color matching error showed significant correlations only in 2 of the 20 subjects for the perceptual matching condition. The distribution of r values was not significantly different from zero for perceptual matching (mean r = −0.0478, SD = 0.138, t test: t (19) = −1.54, P = 0.07).We also averaged the data across all individuals and calculated average error and name density for each hue (Fig. 4). Average name density and average error (both pooled across all subjects) showed a significant negative correlation for memory-based matching (r = −0.555, P < 0.00001) and not for perceptual matching (r = −0.05, P = 0.609). To make sure the effects observed in the memory condition have not originated from any low-level effect potentially present in the results of the perceptual condition, we normalized memory error values to perceptual errors for each hue and correlated them with name density (r = −0.36, P < 0.001). This normalization obviously adds noise to the correlation, but the remaining significant correlation ensures that the memory effect is not shaped by any inhomogeneity in perceptual matching across the color wheel. In sum, this analysis shows that the density of color names varies across the different parts of the color wheel, and that color memory performance is higher in subareas of the wheel that incorporates more color names. However, the density of color names along the wheel does not influence perceptual color matching performance.Open in a separate windowFig. 4.Distribution of color names over the color space is not even and color matching performance reflects it. The parts of the color wheel that are described by more names (higher name density) are remembered more accurately. The abscissa indicates the name density (ND) around each hue on the color wheel and the ordinate represents the error (average of 20 subjects). Each data point depicts one of the 100 tested hues. Left represents performance in perceptual color matching (r = −0.051, P = 0.609) and Right represents performance in memory-based color matching (r = −0.555, P < 0.0001).The method of adjustment used in this study allows variation in color matching time and this can potentially affect the results. To study the potential role of matching time in the phenomena observed here, we first explored the potential effect of matching time on color matching accuracy within the time variation range naturally present in the data. We observed no significant correlation between accuracy (inverse of the error) and matching time across the sampled hues (r = −0.013, P = 0.89) and across the individuals (r = 0.08, P = 0.73) for memory-based color matching in our data (also see SI Appendix, Fig. S2). Next, to reassure that matching time does not affect our main findings, we divided the trials into two groups based on trial matching times: fast trials (trials faster than the mean reaction time) and slow trials (trials slower than the mean reaction time). Our main effect was repeated for both trial types with no significant change in the effect size (SI Appendix, Fig. S3).     

Liver metastases from esophageal carcinoma: is there a role for surgical resection?

Esophageal cancer recurrence rates after esophagectomy are high, and locally recurrent or distant metastatic disease has poor prognosis. Management is limited to palliative chemotherapy and symptomatic interventions. We report our experience of four patients who have undergone successful liver resection for metastases from esophageal cancer. All underwent esophagectomy and were referred to our unit with metastatic recurrent liver disease, two with solitary metastases and two with multi‐focal disease. The patients underwent multidisciplinary assessment and proceeded to a course of neoadjuvant chemotherapy followed by open or laparoscopic liver resection. Three patients were male, and the mean age was 57.5 (range 44–71) years. Response to chemotherapy ranged from partial to complete response. Following liver resection, two patients developed recurrent disease at 5 and 15 months, and both had disease‐specific mortality at 10 and 21 months, respectively. The other two patients remain disease free at 22 and 92 months. Recurrent metastatic esophageal cancer continues to have a poor prognosis, and the majority of patients with liver involvement will not be candidates for hepatic resection. However, this series suggests that in selected patients, liver resection of metastases from esophageal cancer combined with neoadjuvant and adjuvant chemotherapy is feasible, but further research is required to determine whether this can offer a survival advantage.     

Routine endoscopic screening for synchronous esophageal neoplasm in patients with head and neck squamous cell carcinoma: a prospective study

Early detection of synchronous esophageal squamous cell neoplasm (ESCN) in head and neck squamous cell carcinoma (HNSCC) patients can significantly affect their prognosis. We investigated the prevalence of synchronous ESCN and the risk factors for developing ESCN in patients with HNSCC, and evaluated the effect of routine endoscopic screening in these patients. Subjects who were diagnosed as HNSCC from May 2010 to January 2014 were eligible. All patients underwent conventional white light endoscopic examinations with narrow band imaging and Lugol chromoendoscopy. Among 458 subjects screened, 28 synchronous ESCN were detected in 24 patients (5.2%). The prevalence of ESCN was greatest in patients with hypopharyngeal cancer (20.9%). In multivariate analysis, pyriform sinus involvement was independent risk factor for developing synchronous ESCN (odds ratio 171.2, P < 0.001). During the follow‐up period (median, 24 months), the 3‐year overall survival rates was significantly lower in patients with ESCN than in patients without ESCN (54.2% vs. 78.3%, P = 0.0013). Routine endoscopic screening for detecting synchronous ESCN should be recommended for patients with HNSCC, especially those with pyriform sinus involvement.     

Direct-writing color vectorcardiograph

By employing a specially designed instrument, a “color vectorcardiogram”, a single, colored horizontal plane vectorcardiogram (VCG) was written directly on the recording paper. At first, the voltage in the X, Y and Z axes was memorized into the digital memory cells. After that, the voltage in the X and Z axes was slowly read out so that a horizontal plane vectorcardiogram was written directly on the paper of the X-Y recorder. The color of the recording pen varied according to the voltage in the Y axis, which was read out simultaneously with the voltage in the X and Z axes.     

Accuracy of CT in predicting malignant potential of cystic pancreatic neoplasms

Background. Cystic lesions of the pancreas are being identified more frequently. Deciding which asymptomatic lesions can be safely followed with serial imaging and which require resection due to malignant potential is an increasingly common question. Current clinical practice is to rely on characteristics of the lesions on CT scan, and additional information from endoscopic ultrasound with fine-needle aspiration (EUS-FNA) and cyst fluid analysis or endoscopic retrograde pancreatography (ERCP) to assess malignant potential. Hypothesis. The malignant potential of pancreatic cystic lesions cannot be accurately predicted by CT scan. Methods. CT scans from 48 patients with cystic lesions of the pancreas were stripped of patient identifiers and retrospectively presented to two expert radiologists. The radiologists recorded specific characteristics of the lesions thought to be important in the differential diagnosis and their opinion of the likely diagnosis. Diagnostic accuracy was assessed by comparing the radiologists’ diagnoses to the final pathologic diagnosis after resection. To determine if clinical history, EUS-FNA or ERCP findings improved diagnostic accuracy, medical records were retrospectively reviewed and scored as either supporting or not supporting malignant potential of the lesion. Results. Specific diagnoses based on CT findings alone were correct in an average of 39% of the cases. Even when diagnoses were dichotomized as benign (43%) or potentially malignant (57%, papillary mucinous neoplasms, mucinous cystic neoplasms, cancer), determinations based on CT alone were accurate in an average of 61% of cases. Accuracy rates were 60.4 and 62.5% for the two radiologists, although there was only fair agreement between them (Kappa=0.28, 95% CI=(0.01–0.55), p=0.05). When all clinical information available was considered together as a single dichotomous indicator of malignant potential, the indicator was accurate in 90% of the cases (Kappa=0.73, 95% CI=(0.51–0.95, p<0.0001)). Conclusion. Specific preoperative diagnosis of pancreatic cystic neoplasms by CT alone is substantially inaccurate. Complementary tests such as EUS-FNA with fluid analysis and ERCP should be recommended to improve diagnosis especially if nonoperative treatment is planned.     

Lateralization of categorical perception of color changes with color term acquisition

Categorical perception (CP) of color is the faster and more accurate discrimination of two colors from different categories than two colors from the same category, even when same- and different-category chromatic separations are equated. In adults, color CP is lateralized to the left hemisphere (LH), whereas in infants, it is lateralized to the right hemisphere (RH). There is evidence that the LH bias in color CP in adults is due to the influence of color terms in the LH. Here we show that the RH to LH switch in color CP occurs when the words that distinguish the relevant category boundary are learned. A colored target was shown in either the left- or right-visual field on either the same- or different-category background, with equal hue separation for both conditions. The time to initiate an eye movement toward the target from central fixation at target onset was recorded. Color naming and comprehension was assessed. Toddlers were faster at detecting targets on different- than same-category backgrounds and the extent of CP did not vary with level of color term knowledge. However, for toddlers who knew the relevant color terms, the category effect was found only for targets in the RVF (LH), whereas for toddlers learning the color terms, the category effect was found only for targets in the LVF (RH). The findings suggest that lateralization of color CP changes with color term acquisition, and provide evidence for the influence of language on the functional organization of the brain.     

Microcomputed tomography colonography for polyp detection in an in vivo mouse tumor model

This study was initiated to evaluate the efficacy of negative contrast-enhanced microcomputed tomography (microCT) colonography for the noninvasive detection of colonic tumors in living mice. After colonic preparation, 20 anesthetized congenic mice were scanned with high-resolution microCT. Images were displayed by using commercial visualization software and interpreted by two gastrointestinal radiologists, who were unaware of tumor prevalence and findings at gross pathology. Two-dimensional multiplanar images were assessed by using a five-point scale to distinguish colonic tumors (polyps) from fecal pellets (5 = definitely a tumor, 4 = probably a tumor, 3 = indeterminate, 2 = probably not a tumor, 1 = definitely not a tumor). Gross pathologic evaluation of excised mouse colons served as the reference standard. Data analysis included dichotomizing results, with 1-2 indicating no tumor and 3-5 indicating tumor and also receiver operator characteristic curve analysis with area under the curve for threshold-independent assessment. A total of 41 colonic polyps in 18 of the 20 mice were identified at gross examination on necropsy, of which 30 measured 2-5 mm and 11 measured <2 mm in size. The pooled per-polyp sensitivity for lesions >2 mm was 93.3% (56/60). The pooled per-mouse sensitivity for polyps >2 mm was 97.1% (33/34). Pooled specificity for distinguishing fecal pellets from tumor was 98.5% (65/66). The combined area under the curve from receiver operator characteristic curve analysis was 0.810 +/- 0.038 (95% confidence interval, 0.730-0.890). These findings indicate that accurate noninvasive longitudinal monitoring of colon tumor progression or response to various therapies is now technically feasible in live mice by using this microCT colonography method.     

Lung metastasectomy in colorectal cancer: Is this surgery effective in prolonging life?

The commonest context in which pulmonary metastasectomy is performed is for recurrent colorectal cancer. With a more active policy of surveillance among cancer teams, ready access to ever faster CT scans and a willingness to perform further surgery to control recurrent cancer, the practice of pulmonary metastasectomy is increasing. In this pro/con debate the issues are explored. It is recognized by both sides that there is no randomized trial evidence on which to base the practice. The difference of opinion is whether there is sufficient evidence from very many case series of both pulmonary and hepatic metastasectomy on which to base current practice. The surgeon's view is that the weight of evidence from many follow‐up studies is in favour of continuing this practice. The mathematician's view is that case selection could account for nearly all the observed results.     

Senescence and color vision

The usual trichromatic equation for a color match is converted into an algebraic equation consisting of the sum of the contrasts determined by the intensity ratios between the matching stimuli and arbitrary fractions of the proband. The senescence of the preretinal media is shown to affect color matches monotonically, but discrimination steps are affected differently. It is suggested that the senescence observed in tasks involving chromatic discrimination can be explained in terms of the nervous mechanisms subserving other types of contrast discrimination. The possibility of either simplifying or refining some clinical tests also is discussed.     

Universality of color names

We analyzed the World Color Survey (WCS) color-naming data set by using k-means cluster and concordance analyses. Cluster analysis relied on a similarity metric based on pairwise Pearson correlation of the complete chromatic color-naming patterns obtained from individual WCS informants. When K, the number of k-means clusters, varied from 2 to 10, we found that (i) the average color-naming patterns of the clusters all glossed easily to single or composite English patterns, and (ii) the structures of the k-means clusters unfolded in a hierarchical way that was reminiscent of the Berlin and Kay sequence of color category evolution. Gap statistical analysis showed that 8 was the optimal number of WCS chromatic categories: RED, GREEN, YELLOW-OR-ORANGE, BLUE, PURPLE, BROWN, PINK, and GRUE (GREEN-OR-BLUE). Analysis of concordance in color naming within WCS languages revealed small regions in color space that exhibited statistically significantly high concordance across languages. These regions agreed well with five of six primary focal colors of English. Concordance analysis also revealed boundary regions of statistically significantly low concordance. These boundary regions coincided with the boundaries associated with English WARM and COOL. Our results provide compelling evidence for similarities in the mechanisms that guide the lexical partitioning of color space among WCS languages and English.     

Preoperative colonoscopy for patients with gastric adenocarcinoma

Background and Aim:  In patients with gastric adenocarcinoma (GA), the most common double primary cancer is colorectal cancer. The aim of the present study was to evaluate the necessity of preoperative colonoscopy in patients with GA who have no symptoms of colorectal disease or any past/family history of colorectal cancer.
Materials:  Colonoscopy was carried out in 205 patients before gastric surgery for treatment of GA. The prevalence of colorectal neoplasms (CRN, adenoma and adenocarcinoma) was evaluated according to age, sex, body mass index (BMI) and stage, location and differentiation of GA.
Results:  The median age and BMI were 59 years (range 32–81) and 22.9 (range 17.0–42.3), respectively. There were 135 male patients (65.9%). Synchronous adenoma and adenocarcinoma were detected in 68 (33.2%) and four (2.0%) patients, respectively. Univariate analysis showed that patients 50 years and older, male or with multiple GA had a significantly higher incidence of CRN ( P  = 0.005, 0.019, and 0.023, respectively). All of the GA patients with synchronous colorectal adenocarcinoma were older than 50 years. The stage, location and differentiation of GA and BMI did not show a significant difference in the incidence of CRN. Multivariate analysis showed that age (50 years and older) was the only risk factor of CRN in GA patients (odds ratio 2.470; 95% confidence interval 1.058–5.767).
Conclusion:  Preoperative colonoscopy for screening of CRN should be considered in GA patients ≥ 50 years because of a relatively high prevalence of CRN and the possibility of synchronous CRC.     

Chronic immunosuppression does not potentiate the malignant progression of mucinous pancreatic cystic lesions

BackgroundPremalignant mucinous pancreatic cystic lesions (mPCLs) are increasingly identified.AimsIn this study, we aim to assess the effect of selected immunosuppressive therapies on the progression of mPCLs, including side-branch intraductal papillary mucinous neoplasms and mucinous cystic neoplasms.MethodsWe performed a retrospective cohort study of patients with mPCLs diagnosed over a 24-year period who received chronic immunosuppression. Controls were matched on age at cyst diagnosis (±11 yrs) and cyst size (±8 mm). Measured outcomes included increase in cyst size, development of “worrisome features” as defined by consensus guidelines, progression to malignancy, and rate of surgical resection.Results39 patients (mean age 60 yrs) with mPCLs were on immunosuppression. Leading indications for immunosuppression were solid organ transplant (n = 14), inflammatory bowel disease (n = 6), and rheumatoid arthritis (n = 5). 33% were on biologics, 77% on antimetabolites and 79% on multiple medications. Mean cyst size increased from 12.6 mm to 17.8 mm over a median of 16.5 months. 6 patients elected for surgical resection, and none ultimately developed malignancy. 26 cases with follow-up were matched to control subjects, with no significant differences among cases and controls in initial cyst size (12.8 mm vs 11.9 mm, P = 0.69), mean size increase (6.9 mm vs 5 mm, P = 0.47), follow-up interval (24.3 months vs 21.5 months, P = 0.44). No significant differences in the rate of worrisome features, malignancy, or surgical resection.ConclusionsPatients with mPCLs exposed to immunosuppressive medications did not have higher rates of malignancy or development worrisome features in the short term. This suggests that patients with mPCLs can be initiated or maintained on these agents without changes to surveillance practices.