Alpha-naphthyl acetate esterase activity in human foetal lymphocytes

Human foetal mononuclear cells from thymus, spleen, liver, bone marrow and peripheral blood at 8–24 weeks of gestation were examined for cytochemical evidence of acid alpha-naphthyl acetate esterase (ANAE) activity. The focal brownish-red ANAE reaction product (T cell staining pattern) was observed in counterstained cytocentrifuged cell smears in the cytoplasm. ANAE-positive lymphoid cells were first observed in the thymus at 9 weeks of gestation. A gradual increase in frequency of ANAE-positive cells in foetal thymus was observed, from about 10% at 14–15 weeks to about 20% at 22–24 weeks of gestation. By 14 weeks of foetal age, spleen and liver contained a few ANAE-positive cells and after 15 weeks of gestation consistent occurrence of ANAE-positive cells was observed in foetal bone marrow and peripheral blood. These results demonstrate that ANAE-positive lymphocytes first appear in the foetal thymus and are subsequently found in the foetal liver, spleen, bone marrow and peripheral blood.     

Structure of carotid artery in baboon and rat and differences in their response to endothelial denudation angioplasty

BACKGROUND: Most studies dealing with vascular response to injury have been conducted using rodent and rabbit models, although it is expected that the response to injury in these species is dissimilar from man. AIMS: Here we compare the structure of native carotid artery in rat and baboon and the response of these vessels to endothelial denudation angioplasty. METHODS: In both species, the carotid is a musculoelastic artery. Only baboon carotid has a distinct intima, correlating in size with the weight of male baboons. Complete endothelial denudation of left carotid was performed on eight male baboons and 24 male rats by applying an equivalent pull force with a Fogarthy catheter. The animals were sacrificed prior to and 15 min and 2, 3, 4, 7, 14 and 28 days postinjury, one baboon and three rats per time point. RESULTS: Re-endothelialization in the baboon was complete already on day 4, whereas in the rat it was still incomplete on day 28. The proliferative response to injury was far smaller in the baboon than in the rat, the intimal area increased only by 5-fold in baboon compared with 25-fold in rat, and the number of intimal nuclei by 4-fold in baboon compared with 12-fold in rat. Complete compensatory remodelling of the lumen size occurred in the baboon, whereas in the rat remodelling remained incomplete. The cell types participating in the response were, however, similar: deposition of thrombocytes on denuded luminal surface, expression of alpha-actin by intimal cells, and lack of any significant white cell infiltration in the denuded intima. CONCLUSIONS: Baboon carotids are very different from rat carotids both in their native structure and in their response to injury. With the limited amount of information available from human vessels, baboon carotids closely resemble human carotids in both respects.     

New Data for Cholesterol Contents in Meat, Fish, Milk, Eggs and Their Products Consumed in Finland

This study was undertaken to produce cholesterol data in order to update the Finnish National Food Composition Data Base. The sampling included meat, fish, milk, eggs and their products. Sample preparation by a direct saponification method was applied. The cholesterol contents were determined by gas chromatography (GC) using an internal standard method for quantification. In meat and sausages the cholesterol contents ranged from 45 to 84 mg/100 g and from 36 to 75 mg/100 g, respectively. In most fish species the cholesterol contents were slightly higher ranging from 49 to 92 mg/100 g and they did not correlate with the fat contents. The contents in liquid milk products correlated with their fat contents ranging from 6.2 (milk with 1.5% fat) to 77 mg/100 g (cream with 38% fat). The corresponding range for cheese was 33–82 mg/100 g. The mean cholesterol content of eggs was 366 mg/100 g. The results were generally in line with other results, which have been recently obtained. However, for meat and high-fat milk products our results were partly lower than those reported in some food composition tables. The study showed that food composition databases should be periodically updated, i.e., by applying the most recent analytical methods and taking into account changes in foods available for consumption.     

Role of nitric oxide in experimental obliterative bronchiolitis (chronic rejection) in the rat.

The role of nitric oxide in obliterative bronchiolitis development, i.e., chronic rejection, was investigated in the heterotopic rat tracheal allograft model. An increase in the intragraft inducible nitric oxide synthase (iNOS) mRNA and mononuclear inflammatory cell iNOS immunoreactivity was demonstrated during progressive loss of respiratory epithelium and airway occlusion in nontreated allografts compared to syngeneic grafts. In nontreated allografts, however, intragraft nitric oxide production was decreased, most likely because of loss of iNOS epithelial expression. Treatment with aminoguanidine, a preferential inhibitor of inducible nitric oxide synthase, was associated with enhanced proliferation of alpha-smooth muscle actin immunoreactive cells and the intensity of obliterative bronchiolitis early after transplantation. Aminoguanidine treatment did not affect iNOS mRNA synthesis or intragraft nitric oxide production, but decreased iNOS immunoreactivity in smooth muscle cells. Treatment with L-arginine, a precursor of nitric oxide, significantly reduced obliterative changes. L-arginine supplementation enhanced intragraft iNOS mRNA synthesis and iNOS immunoreactivity in capillary endothelial and smooth muscle cells as well as intragraft nitric oxide production. Immunohistochemical analysis of allografts showed that neither iNOS inhibition nor supplementation of the nitric oxide pathway affected the number of graft-infiltrating CD4+ and CD8+ T cells, ED1+ and ED3+ macrophages, immune activation with expression of IL-2R or MHC class II, or production of macrophage or Th1 cytokines. In contrast, L-arginine treatment was associated with increased staining for Th2 cytokines IL-4 and IL-10. In conclusion, this study demonstrates that nitric oxide has a protective role in obliterative bronchiolitis development in this model, and suggests that nitric oxide either directly or indirectly inhibits smooth muscle cell proliferation and modulates immune response towards Th2 cytokines.     

Determination of Sterols in Foods: Recovery of Free, Esterified, and Glycosidic Sterols

A reliable method for routine use in the determination of sterols in foods is described. In the sample preparation procedure, acid hydrolysis prior to alkaline saponification was used to liberate glycosidic sterols. Sterols were analyzed by capillary gas chromatography as the trimethylsilyl ether derivatives and quantified using an internal standard (dihydrocholesterol). In method development, the main focus was on optimization of hydrolysis conditions and on extraction of sterols after hydrolysis. Performance of the proposed method was compared to the same method without the acid hydrolysis step. Method validation included recovery tests of added free sterol, esterified sterol, and glycosidic sterol. Major plant sterols, including stanols, and cholesterol could be quantitated at levels 0.5–800 mg/100 g when the method was applied to food samples.