The Role of Extended Lymphadenectomy for Adenocarcinoma of the Head of the Pancreas: Strength of the Evidence

With improvements in the safety of Whipple resection in recent decades, surgeons have continued to explore the role of more extensive lymphadenectomy in hope of improving long-term survival. A systematic literature search of level I evidence addressing the role of the extent of lymphadenectomy was undertaken. Only reports of prospective, randomized controlled trials comparing pancreaticoduodenectomy with standard lymphadenectomy to pancreaticoduodenectomy with extended lymphadenectomy where information regarding survival, morbidity, mortality, the number of resected lymph nodes in each group and detailed operative technique were included. Four prospective, randomized trials comprising some 424 patients and one meta-analysis were identified. In aggregate, these studies confirmed that the number of resected lymph nodes was significantly higher in the pancreaticoduodenectomy with extended lymphadenectomy group. Morbidity and mortality rates were comparable. Postoperative diarrhea in the early months after operation was problematic in patients undergoing extended lymphadenectomy. In none of the studies was a benefit in long-term survival demonstrated. Standard pancreaticoduodenectomy continues to be the operation of choice for adenocarcinoma of the head of the pancreas. Presented at The Society for Surgery of the Alimentary Tract Postgraduate Course “Systematic Reviews of Pancreaticobiliary Disease Customized for the Gastroenterologist and Gastrointestinal Surgeon” on May 20, 2007, Washington, D.C.     

Some Guidelines for the Use of Stimulus Modifications in Teaching Response Topography to People with Developmental Disabilities

The use of stimulus modifications in teaching involves altering the materials of a task in order to simplify its execution. Though their use in teaching stimulus discriminations to people with developmental disabilities has been extensively investigated, less attention has been given to their utilization in teaching response topography. This paper offers some general guidelines about their use for this purpose. In relation to their design, it is suggested that the aim should be to reduce the demands made by task components, to eliminate components, and/or to increase the attentional value of the discriminating features of the response topography. In relation to their application, guidelines are suggested about when they should be employed in conjunction with response prompts; when they should be used, either alone or in conjunction with response prompts, in preference to response prompts alone; whether one or a series of modifications is required; and at what point during teaching should probe trials on the unmodified task be introduced.     

Insulin like growth factor I is an autocrine regulator of human colon cancer cell differentiation and growth.

The polyanionic compound suramin triggers enterocyte-like differentiation of the human colic adenocarcinoma cell clone HT29-D4. We now demonstrate that suramin interferes with the binding of IGF-I to its receptor at the surface of HT29-D4 cells. Half-maximum inhibition of 125I-IGF-I binding was obtained in the presence of 25 micrograms/ml suramin. Moreover, the drug was able to dissociate 125I-IGF previously bound to its cell surface receptor. Affinity labeling HT29-D4 cells were cultured in the presence of 10 micrograms/ml of alpha-IR3, a monoclonal antibody directed against the binding site of IGF-I, an inhibition of cell proliferation and a stimulation of cell differentiation was observed. After 10 days of treatment with alpha-IR3, HT29-D4 cells formed a regular monolayer of enterocyte-like cells exhibiting an apical brush border and tight junctions delimiting two domains of the plasma membrane (apical and basolateral). Furthermore, we show that IGF-I significantly increased the initial rate of glucose uptake by HT29-D4 cells, while we have previously shown that suramin decreased glucose consumption. From these data we conclude that IGF-I secreted by the cells themselves, stimulates proliferation of HT29-D4 cells via an autocrine mechanism. Blockade of this stimulation by suramin or by a specific monoclonal antibody inhibits cell growth, glucose uptake and triggers the process of enterocytic differentiation.     

Cognitive consequences of early phase of literacy.

The effect of the degree of illiteracy (complete or incomplete) on phonological skills, verbal and visual memory and visuospatial skills is examined in 97 normal Brazilian adults who considered themselves illiterate, and 41 Brazilian school children aged 7 to 8 years, either nonreaders or beginning readers. Similar literacy effects were observed in children and in adults. Tasks involving phonological awareness and visual recognition memory of nonsense figures distinguish the best nonreaders and beginning readers. Children performed better than adults at oral repetition of short items and figure recall, and adults better than children at semantic verbal fluency, digit span, and word list recall. A principal component analysis of the correlations between tasks showed that phonological awareness/reading, phonological memory/oral repetition, and semantic verbal memory/fluency tasks, generated different components. The respective role of culturally based preschool activities and literacy on the cognitive functions that are explored in this study is discussed.     

Quality of life after acoustic neuroma surgery

Objective: To assess how surgery affected the quality of life of patients with acoustic neuromas and to investigate possible predictors of the functional outcome following surgery. Study Design: A questionnaire based on the Glasgow Benefit Inventory was completed by patients randomly selected following acoustic neuroma surgery. Setting: Skull base surgery unit of a university teaching hospital (tertiary referral center). Patients: Fifty-three patients with acoustic tumors (follow-up, 1 to 3 y). Results: With regard to overall quality of life, nine patients (17.4%) reported that it became better, 28 patients (53.8%) worse, and 15 patients (28.8%) that it remained the same. Four patients (7.8%) became better off financially, 15 patients (29.4%) worse, and 32 (62.8%) remained unchanged. Forty-one patients (78.8%) did not change their occupation, and 11 (21.2%) had to change their occupation, mainly because of the adverse effects of the operation. With regard to the age at operation, older patients were found to have better overall quality of life. Moreover, younger patients had worse postoperative financial status and they were more likely to change their occupation after the operation. The tumor size did not significantly affect the overall postoperative quality, but it did affect the postoperative financial status (patients with larger tumors were more likely to have worse postoperative financial status). Conclusion: Acoustic neuroma surgery has a significant impact on patients' overall quality of life. Surgeons proposing to operate on small tumors should not assume that the impact on patients' life will be necessarily less than that following the removal of larger tumors. All patients, especially in the younger age group, should be prepared and thoroughly informed about the consequences of the operation on their quality of life.     

Effects on Behaviour and EEG of Single Chain Phospholipases A2 from Snake and Bee Venoms Injected into Rat Brain: Search for a Functional Antagonism

Abstract: Three phospholipase A₂ (PLA₂s), OS₁ and OS₁ purified from the taipan snake venom Oxyuranus scutellatus scutellatus and bee venom PLA₂ were injected to rats by the intracerebroventricular route. OS₁ showed no sign of neurotoxicity at doses at which OS₂ and bee venom PLA₂ produced multiform dose-dependent behavioural effects including motor disturbances (stereotyped movements), compulsive scratching, convulsions and breathing difficulties. EEG recordings showed at the very time when the animal was motionless the induction of several episodes of a low frequency hippocampal theta rhythm, index of long-term changes in synaptic neuroplasticity. Spike-wave discharges were also produced but the occurrence was not systematic. These seizures were often accompanied with behavioural convulsions. Blockers of NMDA receptors and drugs modifying the GABAergic transmission could not abolish the neurotoxic effects of PLA₂s except for diazepam (10 mg/kg intraperitoneally) that prevented only OS₂-induced disturbances. Blockers of L-type Ca²⁺ channels and K⁺ channel openers were also without effect. The toxicity of OS₂ and bee venom PLA₂ is probably due to their initial specific binding to their neuronal receptor sites.