Memory for novel and familiar spatial and linguistic temporal distance information in hypoxic subjects

Hypoxia is known to cause damage to the hippocampus as well as memory impairments in humans. Subjects who have experienced a hypoxic episode and age-, gender-, and education-matched control subjects were tested for memory for spatial and linguistic temporal distance information using sentences and spatial locations. Each test contained a familiar component based on information that is meaningful and is thought to be stored as part of the knowledge system (prior knowledge) as well as a novel component based on new information. Subjects were presented a list of eight-word sentences or eight spatial locations (Xs) on a grid on a Macintosh computer and tested for memory for temporal distances. Temporal distance is defined as the number of items that occur between the two test items, in the study phase. Compared to control subjects, hypoxic subjects were impaired across all temporal distances on the novel spatial and linguistic tasks. As the temporal distance increased, hypoxic subjects showed some improvement in memory performance. In addition, memory of familiar temporal distance information was also assessed. Hypoxic subjects were impaired, compared to control subjects, for familiar temporal distance information. For hypoxic subjects there was a proportionally greater impairment for novel compared to familiar spatial and linguistic temporal distance information. There was a significant difference in their performance on the familiar temporal distance tasks compared to their performance on the novel tasks. Prior knowledge appears to attenuate the deficits seen in the familiar temporal distance tasks. It appears that hypoxia may cause more selective damage to the hippocampus and this damage is sufficient to produce profound memory impairments for primarily novel and less severe memory impairments for familiar spatial and linguistic temporal distance information.     

Neutralizing antibodies to Escherichia coli Vero cytotoxin 1 and antibodies to O157 lipopolysaccharide in healthy farm family members and urban residents

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Escherichia coli O157 lipopolysaccharide (LPS) was developed with sera from 63 children with confirmed recent E. coli O157 infection and from 256 age-stratified urban controls. The median ELISA values for control and case sera were 0.05 (interquartile range, 0 to 0.20; mean +/- standard deviation [SD], 0.15 +/- 0.22) and 1.41 (interquartile range, 1.11 to 1.59; mean +/- SD, 1.41 +/- 0.53), respectively (P < 0.001). With a breakpoint of 0.59 (mean ELISA value of the control sera + 2 SDs), the assay had a sensitivity, specificity, and positive and negative predictive values of 95, 94, 80, and 98%, respectively, for recent E. coli O157 infection. The O157 LPS assay and Vero cytotoxin (VT) 1-neutralizing-antibody (NAb) assay were used to compare the relative frequencies of O157 LPS antibodies and VT1-NAbs in an age-stratified urban population from Toronto, Ontario, Canada, and in 216 healthy family members from dairy farm in southern Ontario. The frequency of O157 LPS antibodies was about threefold higher in dairy farm residents (12.5%) than in urban residents (4.7%) (P < 0.01). Similarly, the frequency of VT1-NAbs was about sixfold higher in dairy farm residents (42.0%) than in urban residents (7.7%) (P < 0.001). These findings are consistent with a greater level of exposure of dairy farm residents to VT-producing E. coli (VTEC) strains. The high rate of seropositivity to VT1 in farm residents probably reflects the booster effect of repeated VTEC exposures and argues against a sustained generalized immunosuppressive effect of VT1. Seroepidemiological studies may help in assessing the level of exposure of different populations to VTEC strains.     

MR imaging of soft-tissue masses: role of gadopentetate dimeglumine

To assess the effectiveness of gadopentetate dimeglumine in the magnetic resonance (MR) imaging evaluation of soft-tissue masses without osseous involvement, 30 patients underwent MR imaging before and after administration of contrast material (0.1 mmol/kg). Of the 30 lesions, 22 were benign and eight were malignant; histologic confirmation was available in all lesions except one benign lesion. Overall, enhancement was detected in 26 (87%) of 30 lesions: 18 (82%) of the 22 benign lesions and eight (100%) of eight malignant lesions. Enhancement was characterized as homogeneous (two [11%] benign lesions, two [25%] malignant lesions), inhomogeneous (11 [61%] benign lesions, six [75%] malignant lesions), or peripheral (five [28%] benign lesions, no malignant lesions). Of the 19 lesions assessed for a change in enhancement over time, seven (37%) showed an increase and two (11%) showed a decrease in signal intensity. The authors conclude that benign and malignant soft-tissue lesions could not be differentiated solely on the basis of enhancement (pattern, degree, or time course).     

Flavone acetic acid enhances accumulation of IL-2 activated NK cells within established metastases

OBJECTIVE: In 1995, we presented our experience in hysteroscopic resection of hemorrhagic submucous fibroids in 196 patients. The objective of the present work was to analyze functional outcome three years later. PATIENTS: One hundred ninety-six patients with abnormal uterine bleeding were treated between 1987 and 1993. Equipment, techniques, characteristics of the procedures and early results were detailed in the previous article. RESULTS: With a mean follow-up of 73 months (range 50,104), results were: 13.8% of the patients were lost to follow-up; 68.4% had symptomatic improvement and failure was observed in 17.8% (subsequent hysterectomy in 12.7%). Forty-nine patients had repeat resection in this series; 61 became menopausal after surgery, and 21 were taking hormone replacement therapy with good results. CONCLUSION: Developed as an alternative to hysterectomy, operative hysteroscopy has proven to be a safe and effective procedure. This treatment modality appears to give satisfactory long-term results, with a low rate of complications.     

Regulation of intestinal nutrient transport is impaired in aged mice

To determine the effect of age on the regulation of intestinal nutrient absorption, we fed young (7.6-mo-old) and aged (24.8-mo-old) C57BL mice diets designed to stimulate in vitro sugar or amino acid uptake in the isolated small intestine. In each age group, diet had no effect on feeding rates and body weights. D-Glucose and D-fructose uptakes by the small intestine each increased by about two times in young and 1.5 times in aged mice fed high carbohydrate diets as compared with those fed no carbohydrate. Adaptive increases in uptake by the aged group were not only reduced but also restricted to more proximal regions of the small intestine. In both age groups, diet-stimulated increases in D-glucose transport were accompanied by parallel increases in number of Na(+)-D-glucose cotransporters as estimated by specific phlorizin binding. Diet had no effect on transporter Kd for phlorizin, turnover rate of each transporter, mucosal mass or mucosal permeability. A high protein diet stimulated the uptake of L-aspartate and L-proline in young mice and of only L-aspartate in aged mice. Uptake of essential amino acids and of nonessential amino acids sharing transporters with essential ones were not regulated. Although aged mice possess adaptive mechanisms to diet that are similar to those in young mice, the effectiveness of these mechanisms may be impaired with age and may result in malabsorption symptoms so prevalent in the elderly.