Randomized trial of weight-loss-diets for young adults varying in fish and fish oil content.

OBJECTIVE: To investigate the effect of including seafood and fish oils, as part of an energy-restricted diet, on weight loss in young overweight adults. DESIGN: Randomized controlled trial of energy-restricted diet varying in fish and fish oil content was followed for 8 weeks. Subjects were randomized to one of four groups: (1) control (sunflower oil capsules, no seafood); (2) lean fish (3 x 150 g portions of cod/week); (3) fatty fish (3 x 150 g portions of salmon/week); (4) fish oil (DHA/EPA capsules, no seafood). The macronutrient composition of the diets was similar between the groups and the capsule groups, were single-blinded. SUBJECTS: A total of 324 men and women aged 20-40 years, BMI 27.5-32.5 kg/m(2) from Iceland, Spain and Ireland. MEASUREMENTS: Anthropometric data were collected at baseline, midpoint and endpoint. Confounding factors were accounted for, with linear models, for repeated measures with two-way interactions. The most important interactions for weight loss were (diet x energy intake), (gender x diet) and (gender x initial-weight). RESULTS: An average man in the study (95 kg at baseline receiving 1600 kcal/day) was estimated to lose 3.55 kg (95% CI, 3.14-3.97) (1); 4.35 kg (95% CI, 3.94-4.75) (2); 4.50 kg (95% CI, 4.13-4.87) (3) and 4.96 kg (95% CI, 4.53-5.40) on diet (4) in 4 weeks, from baseline to midpoint. The weight-loss from midpoint to endpoint was 0.45 (0.41-0.49) times the observed weight loss from baseline to midpoint. The diets did not differ in their effect on weight loss in women. Changes in measures of body composition were in line with changes in body weight. CONCLUSION: In young, overweight men, the inclusion of either lean or fatty fish, or fish oil as part of an energy-restricted diet resulted in approximately 1 kg more weight loss after 4 weeks, than did a similar diet without seafood or supplement of marine origin. The addition of seafood to a nutritionally balanced energy-restricted diet may boost weight loss.

Pathogenesis of central nervous system lesions in visna cell-mediated immunity and lymphocyte subsets in blood, brain, and cerebrospinal fluid.

The time course and titers of antibodies did not correlate with the severity of CNS lesions whereas the CMI did, indicating that CMI may play an important role in lesion development. The correlation of the number of CD8 positive cells in the CSF with the severity of lesions and the reversed ratio of CD4/CD8 positive cells in the diffusely infiltrated neuroparenchyma indicates that the CD8 positive T cells may be an important effector cell in the induction of CNS lesions.

Quantitative assessment of the astrocytic response in natural scrapie of sheep.

Scrapie of sheep and goats belongs to the spongiform encephalopathies, a term derived from the characteristic vacuolar degeneration in the central nervous system. Astrocytosis has been described, but a systematic quantitative study has not been made. Such a study is important in resolving the still controversial issues as to whether the astrocytic response is caused directly by the infectious agent or represents a secondary reaction to tissue damage. In this study the numbers of astrocytes in 12 sheep with scrapie and 12 healthy sheep of a similar age were assessed and compared. Sections from eight planes of the brain were immunostained with anti-glial fibrillary acidic protein (GFAP) for astrocytes and their numbers counted in 40 areas of 1 mm2. The main findings were as follows. (1) A significant increase of astrocytes was detected in sheep with scrapie. (2) Astrocytosis was not usually related to the severity of the characteristic vacuolar lesions, indicating that it was at least partly due to a direct effect of the infectious agent but was not a secondary response to the neuronal damage. (3) The astrocytic response varied considerably between individual affected sheep; this may have been due to differences in agent strains, host response, or both.

Pathogenesis of central nervous system lesions in visna: cell-mediated immunity and lymphocyte subsets in blood, brain and cerebrospinal fluid.

There are several indications that central nervous system (CNS) lesions in visna are immune-mediated and that cell-mediated immunity (CMI) may be of importance in the initiation of the lesions. To study the role of CMI in the pathogenesis of CNS lesions, five sheep were infected by intracerebral inoculation with visna virus and observed for 1 year. The following parameters were monitored at regular intervals: (1) neutralizing and ELISA antibodies; (2) visna virus-specific stimulation of lymphocytes from peripheral blood; (3) lymphocyte subpopulations in peripheral blood, cerebrospinal fluid (CSF) and brain at sacrifice. The CNS lesions were graded and compared with other parameters. The time course and titers of antibodies did not correlate with the severity of CNS lesions whereas the CMI did, indicating that CMI may play an important role in lesion development. The correlation of the number of CD8-positive cells in the CSF with the severity of lesions and the reversed ratio of CD4/CD8-positive cells in the diffusely infiltrated neuroparenchyma indicates that the CD8-positive T lymphocyte may be an important effector cell in the induction of CNS lesions.