Age, working memory, and on-line syntactic processing in sentence comprehension.

One hundred twenty-seven individuals who ranged in age from 18 to 90 years were tested on a reading span test and on measures of on-line and off-line sentence processing efficiency. Older participants had reduced working-memory spans compared with younger participants. The on-line measures were sensitive to local increases in processing load, and the off-line measures were sensitive to the syntactic complexity of the sentences. Older and younger participants showed similar effects of syntactic complexity on the on-line measures. There was some evidence that older participants were more affected than younger participants by syntactic complexity on the off-line measures. The results support the hypothesis that on-line processes involved in recognizing linguistic forms and determining the literal, preferred, discourse-coherent meaning of sentences constitute a domain of language processing that relies on its own processing resource or working-memory system.

Rectourethral fistula and massive rectal bleeding from iodine-125 prostate brachytherapy: a case report.

Iodine-125 brachytherapy is an effective well-tolerated treatment for localized prostate cancer. Gastrointestinal complications of brachytherapy (minor rectal bleeding or tenesmus) are uncommon. Rectal ulceration or rectourethral fistulas after prostate brachytherapy are rare. We present a case of massive refractory rectal bleeding and rectourethral fistula, a complication of prostate brachytherapy never before reported. As a result of the patient's life-threatening symptoms aggressive surgical therapy was necessary.

Chimpanzee sign language and Darwinian continuity: evidence for a neurological continuity for language.

The current article addresses the empirical validity of the Cartesian view of language by first examining a sample of the results generated by over 30 years of chimpanzee sign language studies and then examining some neurological and behavioral data that accounts for the similarity between human and nonhuman communication systems. Finally an attempt will be made to propose a unified model of language that accounts for these findings and shows how the Cartesian world view has proposed a theory of language that is incomplete.

The relationship between measures of working memory and sentence comprehension in patients with Alzheimer's disease.

Patients with dementia of the Alzheimer's type (DAT) and age- and education-matched older volunteers were tested on a battery of working memory tests, as well as on two tests of sentence comprehension. Patients had reduced spans and impaired central executive processes in working memory but showed normal effects of phonological and articulatory variables on span. On the sentence comprehension tasks, DAT patients showed effects of the number of propositions in a sentence but not of syntactic complexity. Impairment in the central executive processes of working memory in DAT patients was correlated with the effect of the number of propositions in a sentence on the sentence comprehension tasks. The results suggest that patients with DAT have working memory impairments that are related to their ability to map the meanings of sentences onto depictions of events in the world.

Results of local excision of benign and malignant rectal lesions.

Local excision of selected rectal cancers is an acceptable alternative to radical surgery. The results of local excision of various rectal lesions using either the transanal or trans-sacral approach were reviewed over a 10-year period at this institution. A total of 56 procedures were performed on 47 patients (50 transanal/six trans-sacral). The trans-sacral approach was used six times on five patients for lesions averaging a distance of 8 cm from the anal verge. The transanal approach was used 50 times on two patients for lesions occurring at an average distance of 5 cm from the anal verge. Twenty-six malignant lesions were excised (25 transanal/one trans-sacral) with pathologies ranging from poorly to well-differentiated adenocarcinoma. Staging included 12 T1 lesions (46%), 10 T2 lesions (38%), and four T3 lesions (16%). Eighteen malignancies were completely excised and recurrence occurred in four of 18 (22%) with an average follow-up of 2.3 years (range 0-10 years). Local recurrence occurred in two patients (T1 and T2 lesions) and recurrence was in the form of distant metastasis in two patients (two T3 lesions). Three of the recurrences occurred in patients with T3 lesions (three of four; 75%), two occurred in a patient with a T2 lesion (two of 10; 20%), and one occurred in a patient with a T1 lesion (one of 12; 8%). There were no cancer-related deaths during the study period. Twenty-six premalignant lesions (adenomatous polyps) and four benign lesions were excised (25 transanal/five trans-sacral). Local recurrence occurred 10 times with an average follow-up of 1.8 years. In conclusion local excision of certain rectal cancers is an acceptable alternative in the treatment of these malignancies.

Sentinel lymph node mapping for carcinoma of the colon: a pilot study.

Sentinel lymph node (SLN) mapping has evolved into the standard of care for melanoma and may replace routine node dissection in the treatment of breast cancer. There are few data evaluating sentinel node mapping in patients with cancer of the colon. This trial represents our initial experience with SLN mapping for carcinoma of the colon. SLN mapping was performed in 22 patients most of whom had biopsy-proven adenocarcinoma of the colon. One milliliter of isosulfan blue was injected with a 25-gauge needle into the subserosa at four sites around the edge of the palpable tumor. The SLN was identified visually and excised. A standard lymphadenectomy was then performed. The SLN was analyzed with standard hematoxylin and eosin evaluation. Immunohistochemical techniques for carcinoembryonic antigen and cytokeratin (Imm) were performed if the H&E was negative. The mapping added approximately 5 minutes to the total operative time and no adverse reactions to the dye occurred. A SLN was identified in 20 of 22 cases. In cases with negative lymph nodes the SLN was predictive of all the regional nodes by both H&E and Imm (14 of 14). In patients with positive lymph nodes the SLN was predictive in all cases (six of six). In one case the only node with disease was the SLN, and in this case the diease was identified by only Imm; thus this patient was upstaged. SLN mapping is feasible and safe and can readily be performed in patients with colonic cancer. In conjunction with SLN mapping, Imm techniques may upstage a subset of patients likely to be at increased risk for metastatic disease. Consequently SLN mapping of colon cancer should be evaluated in large prospective trials.

Verbal working memory and sentence comprehension.

This target article discusses the verbal working memory system used in sentence comprehension. We review the concept of working memory as a short-duration system in which small amounts of information are simultaneously stored and manipulated in the service of accomplishing a task. We summarize the argument that syntactic processing in sentence comprehension requires such a storage and computational system. We then ask whether the working memory system used in syntactic processing is the same as that used in verbally mediated tasks that involve conscious controlled processing. Evidence is brought to bear from various sources: the relationship between individual differences in working memory and individual differences in the efficiency of syntactic processing; the effect of concurrent verbal memory load on syntactic processing; and syntactic processing in patients with poor short-term memory, patients with poor working memory, and patients with aphasia. Experimental results from these normal subjects and patients with various brain lesions converge on the conclusion that there is a specialization in the verbal working memory system for assigning the syntactic structure of a sentence and using that structure in determining sentence meaning that is separate from the working memory system underlying the use of sentence meaning to accomplish other functions. We present a theory of the divisions of the verbal working memory system and suggestions regarding its neural basis.

Task demands and sentence comprehension in patients with dementia of the Alzheimer's type.

Patients with dementia of the Alzheimer's type (DAT) and matched normal controls were given three tests of syntactic comprehension in which nonlinguistic visual and memory task demands were varied. In all tasks, subjects were presented spoken semantically reversible sentences with a variety of syntactic structures and required to match the sentence to a picture. In the first experiment, subjects matched the spoken sentence to one of two pictures that appeared either before or immediately following the presentation of the sentence. The target picture depicted the spoken sentence correctly and the foil depicted the reversed thematic roles to those in the sentence (i.e., it was a syntactic foil). The second experiment employed a sentence video-verification task in which subjects were required to determine if the spoken sentence matched a videotaped depiction of the action in the sentence or a syntactic foil. In the third experiment, in different conditions, subjects were required to determine whether the spoken sentence matched a single picture or to choose the picture that matched the sentence from an array of two or three pictures. In this experiment, both lexical and syntactic foils were used. In all tasks, DAT patients were affected by the number of propositions in the presented sentence, but not by the syntactic complexity of the sentence. Control subjects also were unaffected by the syntactic complexity of the sentence; the number-of-proposition effect was present in some experiments in the control population. Comparison of performance across the one-, two-, and three-picture versions of the task showed that the magnitude of the effect of number of propositions increased as the number of pictures in the array increased. In addition, analysis of the data from each of the tasks separately showed that the effect of number of propositions only occurred when subjects were attempting to match the target to a syntactic foil (one-picture version) or to choose between the target and a syntactic foil (two- and three-picture versions). The results support the view that patients with DAT do not have disturbances affecting syntactic processing. In addition, they suggest that the effect of number of propositions arises at a stage of analysis that is partially separate from assigning sentence meaning, such as in holding a representation of the sentence in memory until the pictures can be analyzed and encoded and/or in comparing the results of the picture analysis with a stored representation of the sentence meaning.

[Ileoanal reservoir: new concepts and current results]. / El reservorio ileoanal: nuevos conceptos y resultados actuales.

More than 1,800 ileoanal pouches have been performed at the Mayo Clinic since 1981 and results have been satisfactory in more than 90% of the patients. However, we continue to search for alternatives to improve postoperative results and avoid the complications that currently occur in a minority of patients. During the last two years new concepts and surgical techniques for the construction of the ileoanal reservoir have been described. Herein we present those innovations and compare them to our current institutional practice.

Working memory and on-line sentence comprehension in patients with Alzheimer's disease.

We examined the ability of patients with dementia of the Alzheimer's type (DAT) and normal controls to perform a sentence acceptability judgment task that required determining the referent for a reflexive pronoun. Performance on three different sentence types that differed in terms of syntactic complexity was assessed. Subjects performed the task alone and under two different dual-task conditions which required continuous, externally paced responses. DAT patients were more affected than controls by the dual-task conditions, but were not disproportionately impaired on the more complex sentence types. The failure of DAT patients to be disproportionately affected on the most complex sentence types in the dual-task conditions provides evidence for the separation of the processing resources that are used in sentence comprehension from those involved in other tasks.

Determinants of sentence comprehension in aphasic patients in sentence-picture matching tasks.

The results of two studies of sentence comprehension in aphasic patients using sentence-picture matching tests are presented. In the first study, 52 aphasic patients were tested on 10 sentence types. Analysis of the number of correct responses per sentence type showed effects of syntactic complexity and number of propositions. Factor analysis yielded first factors that accounted for two-thirds of the variance in performance to which all sentence types contributed. Clustering analysis yielded groups of patients whose performances progressively deteriorated and in which performance was more affected by sentence types that were harder for the group overall. These results were very similar to those previously obtained using an enactment task. In the second study, 17 aphasic patients were tested on the same 10 sentence types using both sentence-picture matching and enactment tasks. Correlational analyses showed that performance on the two tests was significantly correlated across both subjects and sentences. The results provide data relevant to the determinants of the complexity of a sentence in auditory comprehension.

The use of contextual information related to general world knowledge by right brain-damaged individuals in pronoun resolution.

This study investigated the ability of right brain-damaged individuals (RBD) to use contextual information to resolve ambiguous pronouns. Subjects were presented with sentence pairs and required to resolve the ambiguous pronoun in the second sentence. Contrary to the prevailing view that RBD patients have difficulty using contextual information to integrate language, the RBD group demonstrated a normal pattern of response, demonstrating a sensitivity to the pragmatic information contained in the leading sentence. They responded more quickly to sentences with a pragmatically constrained preferred referent than to those sentences for which there was no preferred referent. As well, they chose the preferred referent significantly more often than the non-preferred referent. These results suggest that RBD patients can use contextual information at the level of a minimal discourse (i.e., two sentences).

The use of contextual information by right brain-damaged individuals in the resolution of ambiguous pronouns.

Two experiments were conducted with the primary purpose of investigating the ability of right brain-damaged (RBD) individuals to use contextual information--at the level of the single sentence, in terms of the integration of information between clauses, and at the level of a minimal discourse (i.e., two sentences)--in the resolution of ambiguous pronouns. The investigation was extended to a group of left brain-damaged (LBD) and non-brain-damaged (NBD) individuals. Contrary to the prevailing view that RBD patients have difficulty in the use of contextual information to process language, both experiments were consistent in demonstrating that the RBD group was influenced by contextual information in a manner similar to that demonstrated by both the LBD and NBD groups.

Inhibition of experimental gingivitis in beagle dogs with topical salivary histatins.

Histatins, histidine-rich proteins found within parotid and submandibular secretions, are a novel class of endogenous peptides with antimicrobial properties. This masked, randomized, placebo-controlled preclinical investigation examined the effect of 3 topical histatins on the development of plaque and gingivitis in beagle dogs. 16, female, 1-year-old beagles were brought to optimal gingival health by mechanical scaling and polishing followed by rigorous daily tooth brushing. At the conclusion of this pretreatment period, dogs were randomly divided into 4 groups for the application of test formulations, and were placed on a plaque-promoting diet. Test agents included 3 synthetic salivary histatins (histatin 5, P-113 and P-113D) which were incorporated in hydroxypropyl methylcellulose gel at a concentration of 0.125%, and a placebo, or negative control, which was the gel vehicle alone. Throughout the 10-week treatment period, test formulations (2.0 ml) were applied 2 x daily to all premolar teeth using a Monojet syringe. Plaque formation and gingival inflammation were assessed using the plaque (PI) and gingival (GI) indices on days 0, 7, 14, 21, 28, 42, 56 and 70. Furthermore, bleeding to probing was recorded as a percent of sites (%BOP) and according to the modified sulcus bleeding index (mSBI). Comparisons among groups and between group pairs (active versus placebo) were made with Kruskal-Wallis tests with the average of data over the interval, days 14-42, being the primary focus of the analysis. From baseline to day 7, all groups expressed similar indices. Thereafter, overall significant differences among the groups were noted at day 42 for PI, at days 21, 28, 42 and 70 for GI, and at days 14 and 28 for %BOP (p < 0.05). In particular, beagles treated with P-113 demonstrated significantly lower PI scores at day 42 (p < 0.05), significantly lower GI scores from days 21 through 42 (p < 0.05), and significantly lower %BOP scores at days 14 and 28 (p < 0.05) compared to beagles treated with placebo. Beagles treated with P-113D exhibited significantly lower GI at day 42 compared to the placebo (p < 0.05). For the primary analysis conducted over the midtreatment interval (days 14-42), significant differences were detected for all parameters except mSBI (p < 0.05). Accordingly, significantly lower PI scores were found for P-113, lower GI scores for P-113 and P-113D, and lower %BOP for P-113 and P-113D compared to placebo (p < 0.05). These data indicate that in the beagle model, salivary histatins, P-113 and P-113D, topically applied, can significantly reduce clinical signs of plaque formation and gingival inflammation.

In vivo uptake of technetium-99M-sestamibi by parathyroid glands in comparison to surrounding tissues of the neck.

Technetium-99M-sestamibi (Tc-99M-sestamibi) has recently been proven to be a sensitive and specific agent for imaging of parathyroid disease; however, the selective nature of its uptake by different tissues has not been investigated. Fifteen consecutive patients undergoing neck exploration for hyperparathyroidism were given 3 to 15 mCi of Tc-99M-sestamibi at various times before surgery, and at the time of exploration, samples of parathyroid tissue, blood, fat, muscle, and thyroid were taken from the neck. All samples were carefully weighed and counts of radioactivity were measured. Activity was normalized to counts per gram of tissue and counts of radioactivity were compared using a multiple range analysis of variance test. Mean counts per gram (+/- SE) in abnormal parathyroid tissue (adenomas and hyperplastic glands; 1.1 x 10(6) +/- 2.7 x 10(6)) were significantly higher than in any of the other tissues measured (P < 0.05): thyroid, 7.0 x 10(4) +/- 1.6 x 10(4); muscle, 8.9 x 10(4) +/- 2.1 x 10(4); fat, 2.1 x 10(4) +/- 4.2 x 10(3); and blood, 9.8 x 10(3) +/- 2.3 x 10(3). Mean ratios of counts (+/- SE) of abnormal parathyroid tissue to other tissues were found to be as follows: thyroid, 35.3 +/- 12.6; muscle, 17.4 +/- 6.2; fat, 80.7 +/- 20.0; and blood, 161.0 +/- 31.6. From these data, Tc-99M-sestamibi clearly exhibits significantly higher uptake in abnormal parathyroid tissue relative to other tissues measured in the neck. This increased uptake in parathyroid gland tissue accounts for the utility of Tc-99M-sestamibi in localization studies for hyperparathyroidism. Quantification of in vivo uptake of Tc-99M-sestamibi may help refine techniques for improved localization of hyperfunctional parathyroid glands.

The capacity theory of sentence comprehension: critique of Just and Carpenter (1992)

The authors review M.A. Just and P.A. Carpenter's (1992) "capacity" theory of sentence comprehension and argue that the data cited by Just and Carpenter in support of the theory are unconvincing and that the theory is insufficiently developed to explain or predict observed patterns of results. The article outlines an alternative to the capacity theory, according to which the unconscious, obligatory operations involved in assigning the syntactic structure of a sentence do not use the same working memory resource as that required for conscious, controlled verbally mediated processes.

Processing resource capacity and the comprehension of garden path sentences.

Three experiments explored the relationship between verbal working memory capacity and the comprehension of garden path sentences. In Experiment 1, subjects with high, medium, and low working memory spans made acceptability judgments about garden path and control sentences under whole sentence and rapid serial visual presentation (RSVP) conditions. There were no significant differences between subjects with different working memory spans in the comprehension of garden path sentences in either condition. In Experiments 2A and 2B, subjects with high and low working memory spans were tested on the same materials at three RSVP rates. There were no significant differences between subjects with different working memory spans in the magnitude of the effect of garden path sentences at any presentation rate. The results suggest that working memory capacity, as measured by the Daneman and Carpenter (1980) reading span task, is not a major determinant of individual differences in the processing of garden path sentences.

Management of choledocholithiasis encountered during laparoscopic cholecystectomy.

To evaluate the prevailing methods of management and assess the safety of laparoscopic treatment of choledocholithiasis, a retrospective review of all common bile duct explorations (CBDE) initiated during laparoscopic cholecystectomy at the Medical College of Georgia was performed. From December 1990 until December 1994, 604 laparoscopic cholecystectomies were performed. In 28 of these patients (26 female, 2 male) with an age range of 17 to 60 years, CBDE was initiated; 21 were performed laparoscopically, and 7 were converted to open CBDE. The procedure was successful in completely clearing the duct of stones in 24 of 28 cases (17 laparoscopic, 7 open). Postoperative endoscopic retrograde cholangiopancreatography was successfully employed in three of the cases of retained stones, and in the fourth, the stone was felt to be small enough to pass without further intervention. Biliary balloon catheters were successfully used to clear the duct in 8 of 17 laparoscopic CBDEs, and a laparoscopic choledochoscope introduced through the cystic duct was used in 7 cases; both were used in 2 cases. The open CBDEs were performed in standard fashion utilizing balloon catheters and choledochoscopy. The only operative complications were the four above-mentioned cases of retained stones. In summary, choledocholithiasis encountered during the course of laparoscopic cholecystectomy can frequently be managed with a laparoscopic CBDE.

The measurement of verbal working memory capacity and its relation to reading comprehension.

Ninety-four subjects were tested on the Daneman and Carpenter (1980) reading span task, four versions of a related sentence span task in which reaction times and accuracy on sentence processing were measured along with sentence-final word recall, two number generation tasks designed to test working memory, digit span, and two shape-generation tasks designed to measure visual-spatial working memory. Forty-four subjects were retested on a subset of these measures at a 3-month interval. All subjects were tested on standard vocabulary and reading tests. Correlational analyses showed better internal consistency and test-retest reliability of the sentence span tasks than of the Daneman-Carpenter reading span task. Factor analysis showed no factor that could be related to a central verbal working memory; rotated factors suggested groupings of tests into factors that correspond to digit-related tasks, spatial tasks, sentence processing in sentence span tasks, and recall in sentence span tasks. Correlational analyses and regression analyses showed that the sentence processing component of the sentence span tasks was the best predictor of performance on the reading test, with a small independent contribution of the recall component. The results suggest that sentence span tasks are unreliable unless measurements are made of both their sentence processing and recall components, and that the predictive value of these tasks for reading comprehension abilities lies in the overlap of operations rather than in limitations in verbal working memory that apply to both.

On the nature of the phonological output planning processes involved in verbal rehearsal: evidence from aphasia.

This paper describes the performance of an aphasic patient, R.W., in producing the sounds of words and in verbal rehearsal. R.W. showed evidence of retained abilities to access aspects of the forms of spoken words but made numerous phonemic paraphasias in single word production tasks. He did not show features of dysarthria or apraxia of speech. This pattern indicates that his deficit affected a process that plans the phonological forms of spoken words. R.W.'s performances in short-term memory and metalinguistic tasks involving single words were consistent with impaired rehearsal functions. The pattern of results indicates that rehearsal requires planning of the phonological forms of spoken items and suggests that activating entries in the phonological output lexicon is not adequate to permit rehearsal to proceed normally.