Influence of level and duration of feeding polysaccharide (laminarin and fucoidan) extracts from brown seaweed (Laminaria digitata) on quality indices of fresh pork

The effect of level (450 or 900 mg laminarin (L) and fucoidan (F) /kg feed) and duration (3 or 6 wks) of feeding a seaweed (Laminaria digitata) extract containing L/F on the quality of pork (longissimus thoracis et lumborum (LTL)) stored in modified atmosphere packs and on organ lipid stability was examined. Mechanisms of L/F antioxidant activity in LTL were evaluated. Plasma total antioxidant status, LTL pH, colour, microbiology and 'eating quality' sensory analysis were unaffected by dietary L/F. 'Visual' sensory descriptors (purchasing appeal and overall visual acceptability) were enhanced (p<0.05) in L/F450-3 LTL. Lipid oxidation was lower (p<0.05) in L/F450-3 and L/F900-3 LTL and reduced in L/F900-6 kidney homogenates. In cooked minced pork, lipid oxidation was not reduced by dietary L/F. Saturated fatty acids were lower (p<0.05) in L/F900-6 LTL. Results indicated L/F in pig diets for 3 weeks enhanced pork quality.

Evaluation of an opiate-weaning protocol using methadone in pediatric intensive care unit patients

OBJECTIVE

To evaluate the efficacy of a standardized opiate-weaning protocol using methadone compared with methadone weaning before protocol development.

DESIGN

Time series, prospective study with comparison to historical controls.

SETTING

Twenty-bed medical-surgical intensive care unit in an academic children's hospital.

PATIENTS

Ten children, aged 6 months to 18 yrs, who received methadone for weaning from continuous opiate infusions for >or=7 days compared with ten patients undergoing weaning by standardized protocol.

INTERVENTIONS

Institution of standardized opiate-weaning protocol.

MEASUREMENTS AND MAIN RESULTS

Patient age, gender, and diagnosis were similar in both nonprotocol (NP) and protocol (P) groups (p = NS). Days of opiate use were also similar between groups. Nine of ten NP and seven of ten P patients were on continuous fentanyl infusions, and the remainder were on continuous morphine infusions. P patients were weaned significantly faster than NP patients (median, 9 days and 20 days, respectively; p <.001). P patients requiring short-term opiate use also weaned significantly faster than short-term NP patients (median, 5 days and 21.5 days, respectively; p <.001). Withdrawal complications were seen in three NP patients with weaning delayed in two. Two P patients had withdrawal complications with no delay in weaning (p = NS). Significant methadone calculation discrepancy occurred in one NP patient but in no P patients.

CONCLUSIONS

Pediatric intensive care unit patients requiring prolonged opiate use can be weaned by using methadone with minimal signs of withdrawal. Use of a standardized weaning protocol decreased time for weaning without increasing the frequency rate of withdrawal symptoms.

Grafting genetically modified cells to the damaged brain: restorative effects of NGF expression

Fibroblasts were genetically modified to secrete nerve growth factor (NGF) by infection with a retroviral vector and then implanted into the brains of rats that had surgical lesions of the fimbria-fornix. The grafted cells survived and produced sufficient NGF to prevent the degeneration of cholinergic neurons that would die without treatment. In addition, the protected cholinergic cells sprouted axons that projected in the direction of the cellular source of NGF. These results indicate that a combination of gene transfer and intracerebral grafting may provide an effective treatment for some disorders of the central nervous system.

Guam amyotrophic lateral sclerosis-parkinsonism-dementia linked to a plant excitant neurotoxin

The decline in the high incidence of amyotrophic lateral sclerosis, parkinsonism, and Alzheimer-type dementia among the Chamorro population of the western Pacific islands of Guam and Rota, coupled with the absence of demonstrable viral and hereditable factors in this disease, suggests the gradual disappearance of an environmental factor selectively associated with this culture. One candidate is seed of the neurotoxic plant Cycas circinalis L., a traditional source of food and medicine which has been used less with the Americanization of the Chamorro people after World War II. Macaques were fed the Cycas amino acid beta-N-methylamino-L-alanine, a low-potency convulsant that has excitotoxic activity in mouse brain, which is attenuated by N-methyl-D-aspartate receptor antagonists. These animals developed corticomoto-neuronal dysfunction, parkinsonian features, and behavioral anomalies, with chromatolytic and degenerative changes of motor neurons in cerebral cortex and spinal cord. In concert with existing epidemiological and animal data, these findings support the hypothesis that cycad exposure plays an important role in the etiology of the Guam disease.

Vitamin E concentrations in different regions of the spinal cord and sciatic nerve of the rat

Since the spinal cord and peripheral nerves are vulnerable to the effects of vitamin E deficiency, vitamin E concentrations in various discrete regions of these parts of the nervous system of the rat were determined. Furthermore, as acrylamide toxicity and vitamin E deficiency share some neuropathological features, tissue vitamin E concentrations in acrylamide-treated rats were also studied. Male Sprague Dawley rats (200 to 250 g body weight) were fed normal rat chow with or without 0.03% acrylamide in their drinking water. After 24 days, the animals were sacrificed and the tissues assayed for vitamin E by a liquid chromatographic method. Vitamin E concentrations decreased from cerebral cortex to spinal cord with no concentration gradients between different levels of the spinal cord. Sciatic nerve concentration of alpha tocopherol was as high as that of cerebral cortex, and the former also contained measurable amounts of gamma tocopherol. Vitamin E concentrations in the majority of nervous tissues samples remained unchanged with acrylamide treatment.

Effect of acetazolamide on rate of CO2 uptake in the perfused rat brain

The accumulation of acid-labile CO2 was measured in the rat brain at early times after exposure to 30% CO2 in oxygen. In particular, the effect on CO2 accumulation of inhibiting brain carbonic anhydrase with acetazolamide was studied. For 57 rats, a rat head perfusion technique was used which permits control and rapid alteration of arterial acid-base conditions. At a paCO2 of 35 mm Hg, total carbon dioxide of the whole brain remained at a normal mean value of 13.4 +/- 0.6 (S.E.) mM/kg during perfusions 209-160 min long. On 30% CO2, brain CO2 increased rapidly to a mean of 24 mM/kg at 5 min and then much more slowly. The latter curve agreed well with values obtained in intact animals. Pretreatment with acetazolamide had no inhibitory effect on CO2 accumulation at 1-5 min. At 5 min, control brain CO2 was 23.9 +/- 0.6 (n = 10) and acetazolamide-pretreated brain CO2 was 24.4 +/- 0.7 (n = 9). Terminal venous pCO2s were 164-180 and 167-172 mm Hg, respectively. Thirty-one unperfused rats were also investigated with similar results. Acetazolamide-pretreated rats had the same CO2 uptake as controls after 15 min exposure to CO2, rather than lower uptake as would be expected if carbonic anhydrase were rate-limiting. The results suggest the need for reinterpretation of some concepts about the role of carbonic anhydrase in CO2 accumulation in the brain.