Evaluation of spinal evoked potentials: a model for assessment of spinal cord function in isolation

Spinal evoked potentials were recorded from the dorsal columns of in vitro mouse hemicord preparations. The response of these potentials to different periods of hypoxia was studied. A decrease in amplitude of the potential to 50% and 10% of pre-hypoxia reference occurred after 3.19 ± 1.36 and 7.3 ± 2.97 min, respectively. Complete recovery of the potential was seen in specimens exposed to 5 and 10 min of hypoxia. Incomplete recovery occurred with exposure to longer periods of hypoxia. In preparations that remained isoelectric for less than 5 min total recovery was seen.     

Confrontation naming and semantic relatedness judgements in Spanish/English bilinguals

Background: The results of many current studies on naming in bilingualism have provided converging evidence for a semantic representation common to both languages within a bilingual individual. However, the interaction between lexical access and semantic representation in bilinguals is relatively unclear. Aims: To further understand this relationship in normal bilingual individuals, we asked the following questions: (1) Is there homogeneity in naming accuracy for both languages across subjects? We predicted that naming accuracy would differ across subjects based on their proficiency levels in each language. (2) After separating subjects into groups based on their proficiency levels (balanced, Spanish dominant, English dominant), is there a difference in their mean ratings of the semantic similarity of word pairs across proficiency groups? According to the mixed model (De Groot, Dannenburg, & van Hell, 1994), it was predicted that similar mean ratings would be observed across all groups. Methods & Procedures: A total of 23 Spanish/English bilinguals (average age = 35.5 years) completed a confrontation naming task and a semantic relatedness questionnaire in both languages. The same set of stimuli, controlled for various factors, was used for each task in both languages and counterbalanced by language across two sessions. Based on naming performances, participants were assigned to the balanced bilingual (N = 10), English dominant (N = 10), or Spanish dominant (N = 3) group (Kohnert, Hernandez, & Bates, 1998). Outcomes & Results: Overall English mean correct was 94.29%; Spanish was 88.19%. Significant differences in naming were seen between groups, F(2, 85) = 4.3, p =. 01, and within the language dominant groups across subjects (p <. 05) and items (p <. 05). On the semantic relatedness task, no significant difference was observed between the ratings of word pairs in each language across participants or items in any group. Conclusions: Despite differences in lexical access, participants in all proficiency groups rated word pairs similarly, indicating a shared semantic representation for both languages. The mixed model (de Groot et al., 1994) can explain the findings for all groups. Results of this study have clinical implications for bilingual aphasic patients. It is imperative to ascertain a patient's pre‐morbid language use prior to brain damage in order to gauge pre‐morbid proficiencies. Treatment should consider proficiency levels in both languages, with consideration that the strength of connections between each lexicon and from each lexicon to semantic memory may differ.     

The ratio of Matriptase/HAI-1 mRNA is higher in colorectal cancer adenomas and carcinomas than corresponding tissue from control individuals

Background  

It has recently been shown that overexpression of the serine protease, matriptase, in transgenic mice causes a dramatically increased frequency of carcinoma formation. Overexpression of HAI-1 and matriptase together changed the frequency of carcinoma formation to normal. This suggests that the ratio of matriptase to HAI-1 influences the malignant progression. The aim of this study has been to determine the ratio of matriptase to HAI-1 mRNA expression in affected and normal tissue from individuals with colorectal cancer adenomas and carcinomas as well as in healthy individuals, in order to determine at which stages a dysregulated ratio of matriptase/HAI-1 mRNA is present during carcinogenesis.     

Osteocutaneous radial forearm free flaps. The necessity of internal fixation of the donor-site defect to prevent pathological fracture

BACKGROUND: Osteocutaneous radial forearm free flaps have fallen from favor due to pathological fractures of the radius. The purposes of this study were to propose a means to decrease the rate of pathological fracture by prophylactic fixation of the donor-site defect and to evaluate this technique biomechanically. METHODS: Two groups of ten matched pairs of fresh-frozen cadaveric radii were harvested. In Group 1, an eight-centimeter length of radius comprising 50 percent of the cross-sectional area of the bone was removed to simulate an osteocutaneous radial forearm donor-site defect. This defect was created in one member of each pair, with the other bone in the pair left intact. In Group 2, both members of the ten matched pairs of radii had identical defects created as previously described. However, one radius in each pair had a twelve-hole, 3.5-millimeter dynamic compression plate placed across the segmental defect. In each group, five matched pairs were tested to failure in torsion and five matched pairs were tested to failure in four-point bending. RESULTS: In Group 1, the intact radius was a mean of 5.7 times stronger in torsion and 4.2 times stronger in four-point bending than the radius with the segmental resection. In Group 2, the radius that was ostectomized and fixed with a plate was a mean of 4.0 times stronger in torsion and 2.7 times stronger in four-point bending than the ostectomized radius. CONCLUSIONS: Removal of an eight-centimeter segment from the radius dramatically decreased both torsion and bending strength. Application of a plate over the defect in the radius significantly restored the strength of the radius (p = 0.01).     

Novel surgical treatment and gastric pathology in diabetic gastroparesis.

AIMS: Observations are made on four Type 1 diabetic patients with the rare syndrome of intractable vomiting from confirmed gastroparesis, to determine whether radical surgery would alleviate their symptoms and subsequently to examine in detail the gastric histopathology. METHODS: The surgical approach consisted of an approximate 70% resection of the stomach, including the antrum and pylorus, with closure of the duodenum and restoration of gastrointestinal continuity with a 60-cm Roux-en-Y jejunal loop. Four longstanding Type 1 diabetic patients were examined and treated as described. They were all women in the age range 2741 years with grossly abnormal autonomic function tests in whom other causes for gastric paresis had been excluded. RESULTS: Vomiting episodes leading to multiple hospital admissions (6-8) in the year preceding surgery were eliminated in three of the four patients, while in the fourth initial success was followed by the need for dialysis for renal failure. Gastric histopathology showed evidence of smooth muscle degeneration and fibrosis, with eosinophilic inclusion bodies (M-bodies) which appear to be unique to this condition. The findings suggest the presence of a gastromyopathy. CONCLUSIONS: Satisfactory relief of intractable vomiting from diabetic gastroparesis was achieved by a novel radical surgical procedure. Histopathological findings suggest that gastromyopathy may contribute to the production of this syndrome.