Comparative study of low power neodymium-YAG laser interstitial hyperthermia versus ethanol injection for controlled hepatic tissue destruction

A solitary hepatic metastasis is amenable to surgery. However, if surgery is contraindicated or if multiple lesions are present in both liver lobes, other treatment modalities have to be considered. We compared the effect of interstitial laser hyperthermia with damage caused by alcoholization. Six anaesthetized beagle dogs were studied. Three animals were treated with laser hyperthermia. A bare laser fibre (400m diameter) was introduced through a 17-gauge needle, length 170 mm, positioned into the liver under real time ultrasonographic guidance. Lesions were produced by continuous 500-s exposure of 1W YAG laser (Medilas MBB 40N) power. Three dogs were subjected to an injection of 4 ml of 98% pure ethanol into the liver through the same needle system. Two days after the procedure the animals were killed and the livers examined. The surface of the livers treated with the YAG laser were entirely normal; superficial lesions were, however, clearly visible. Laserinduced lesions were well reproducible, clearly demarcated, roughly spherical with a mean diameter of 1.01±0.23 cm (n=16). In contrast, the dogs treated with alcohol had free intraperitoneal serohaemorrhagic fluid and the surface of the liver was diffusely abnormal. The lesions had a more or less cylindrical shape, 1.22±0.43 cm on 0.40±0.10 cm (n=12) although exact measurement was often difficult. The border of the lesions was irregular and there was a clear necrotic zone along the puncture track. On microscopic examination the laser-induced lesions consisted of a central evaporation area, a zone of carbonized material and an outer zone of coagulation necrosis. The alcohol-induced lesions were characterized by both fixation necrosis and coagulative necrosis but surprisingly, there was also necrosis present at a distance of the lesions extending along the centrilobular and even portal veins. These data show that laser-induced interstitial necrosis in the liver is better controlled and more reproducible than necrosis induced by injection of pure ethanol. Moreover, pure ethanol may cause damage to the liver surface and even at a distance of the injection site.     

Relation between gastric emptying rate and rate of intraluminal lipolysis.

The variable gastric emptying rate of a test meal is one of the major problems in evaluating accurately gastrointestinal physiological functions beyond the stomach. The aim of this study was to evaluate the effect of the gastric emptying rate on the rate of intraluminal lipolysis. Thirty four subjects without pancreatic disease (21 with a normal gastric emptying and 13 with a known slow gastric emptying) and 14 subjects with pancreatic disease (four without and 10 with pancreatic insufficiency) were studied using a dual labelled breath test. The test meal consisted of one egg, 60 grams of white bread, 10 grams of margarine, and 150 ml of water (350 kcal). The egg yolk was labelled with 91 mg of 13C-octanoic acid, the margarine was labelled with 296 kBq of distearyl-2-14C-octanoyl-glycerol. Breath samples were taken every 15 minutes during six hours and analysed for 13CO2 and 14CO2 content. The gastric emptying rate of the meal was evaluated by the gastric emptying coefficient, the half emptying time, and the lag phase; the rate of intraluminal lipolysis was evaluated by the six hours cumulative 14CO2 excretion. Despite a clear distinction in the rate of intraluminal lipolysis, no difference could be detected in gastric emptying rate of the test meal between subjects without and with pancreatic disease. In subjects with pancreatic insufficiency, intraluminal hydrolysis was the rate limiting process in fat assimilation; in patients without pancreatic insufficiency, however, gastric emptying could be rate limiting. Therefore, patients with known slow gastric emptying, displayed a significantly decreased rate of intraluminal lipolysis compared with normal controls. This decrease could be corrected for accurately using a correction factor based on the gastric emptying coefficient. In conclusion, the combined 13C-octanoic acid and 14C-mixed triglyceride breath test permits the measurement of gastric emptying rate and intraluminal lipolysis simultaneously in a minimally invasive way. Correction of intraluminal lipolysis rate for gastric emptying rate of the given test meal permits evaluation of fat assimilation rates in a physiological way regardless of gastric emptying disorders.     

Relation between gastric emptying rate and energy intake in children compared with adults.

Measurement of gastric emptying rate of solids in children is difficult because the available methods are either invasive or induce a substantial radiation burden. In this study the newly developed 13C octanoic acid breath test was used to examine the gastric emptying rate of solids and milk in healthy children and to compare gastric emptying in children and adults. Fifteen healthy children and three groups of nine healthy adults were studied, using three different test meals labelled with 50 mg of 13C octanoic acid: a low caloric pancake (150 kcal), a high caloric pancake (250 kcal), and 210 ml of milk (134 kcal). Breath samples were taken before and at regular intervals after ingestion of the test meal, and analysed by isotope ratio mass spectrometry. The gastric emptying parameters were derived from the 13CO2 excretion curves by non-linear regression analysis. No significant difference was found between children and adults in the emptying rate of the low caloric solid test meal. In children as well as in adults, increasing the energy content of the solid meal resulted in a significantly slower emptying rate. The milk test meal, however, was emptied at a faster rate in adults and at slower rate in children compared with the low caloric solid test meal. Moreover, the emptying rate of milk in children was significantly slower than in adults. In conclusion, a similar gastric emptying rate of solids but a slower emptying of full cream milk was shown in children of school age compared with adults, using the non-radioactive 13C octanoic acid breath test.     

The risk of post-operative complications associated with infliximab therapy for Crohn's disease: a controlled cohort study

BACKGROUND: By temporarily suppressing the immune response, the anti-tumour necrosis factor agent, infliximab, may increase the risk of peri-operative complications. AIM: To test this hypothesis for intestinal resection in a cohort of 313 Crohn's disease patients treated with infliximab. Forty received one or more infusions prior to intestinal resection (31/40 within 12 weeks). METHODS: The post-operative events of these patients were compared with those of a control group (infliximab naive) of 39 patients adjusted for age, gender and surgical procedure. Early (10 days) and late (3 months) major or minor complications were identified. RESULTS: The incidence of early minor (15.0% vs. 12.8%) and major (12.5% vs. 7.7%) and late minor (2.5% vs. 5.1%) and major (17.5% vs. 12.8%) complications and the mean hospital stay after surgery (10.3 +/- 4.0 days vs. 9.9 +/- 5.5 days) were similar in both groups. A trend towards an increased early infection rate was found in infliximab pre-treated patients (6 vs. 1; P = 0.10), but more patients in this group received corticosteroids and/or immunosuppressives (29 vs. 16 patients; P < 0.05). CONCLUSION: The use of infliximab before intestinal resection does not prolong the hospital stay and does not increase the rate of post-operative complications.     

EEG markers of future cognitive performance in the elderly

This exploratory follow-up study investigated whether EEG parameters can predict future cognitive performance. Forty elderly subjects, ranging from cognitively unimpaired to those with Alzheimer disease underwent EEG registration at baseline and neuropsychological examination at both baseline and follow-up. We assessed relations between EEG measures and future cognitive performance (i.e., global cognition, memory, language, and executive functioning) controlling for age, follow-up time, and baseline cognitive performance. Regression models were constructed to predict performance on the Cambridge Cognitive Examination, a widely used tool within dementia screenings. Baseline EEG measures, i.e., increased theta activity (4-8 Hz) during eyes closed and less alpha reactivity (8-13 Hz) during eyes open and memory activation, indicated lower global cognitive, language (trend significant), and executive performance at follow-up. A regression model combining baseline cognitive and EEG measures provided the best prediction of future Cambridge Cognitive Examination performance (93%). EEG and cognitive measures alone predicted, respectively, 43% and 92% of variance. EEG and cognitive measures combined provided the best prediction of future cognitive performance. Although the "cognition only" model showed similar predictive power, the EEG provided significant additional value. The added value of EEG registration in the diagnostic work-up of dementia should be further assessed in larger samples.     

Test conditions greatly influence permeation of water soluble molecules through the intestinal mucosa: need for standardisation.

Permeability tests are widely used to investigate the pathogenesis of various gastrointestinal diseases including coeliac disease, infectious diarrhoea, and inflammatory bowel disease. In Crohn's disease they are used as activity parameters by some investigators. Lack of standardisation, however, makes it very difficult to compare data reported in different studies. The aim of this study was to gather permeation data in well controlled test conditions to standardise the methods. Nine healthy volunteers each received five consecutive permeability tests by mouth using polyethylene glycol-400 (PEG-400) and 51Cr-EDTA as probe molecules. The probes were dissolved in water, a glucose solution, a starch solution, a hyperosmolar lactulose-mannitol solution, and a liquid meal. A significantly decreased permeation for both probes was found when given with the hyperosmolar solution. The 51Cr-EDTA permeation was also decreased with water. The permeability index, 51Cr-EDTA/PEG-400, corrected for influencing factors, confirmed that the lactulose-mannitol solution and plain water yield lower values of macro-molecule permeation than starch, glucose or liquid meal. Hyperosmolarity was clearly accompanied by a decrease in permeability probably caused by reversed solvent drag. Interindividual variability of probe permeation and permeability index is very low with a standard liquid meal. It is proposed that for permeability studies a standard liquid meal is always used.