Angiotensinogen genotype, plasma protein and mRNA concentration in isolated systolic hypertension

Isolated systolic hypertension (ISH) occurs predominantly in the elderly, with a considerable morbidity and mortality. Its etiology is unknown but is likely to involve a significant genetic component. The aim of this study was to examine the angiotensinogen gene in ISH. The M235T and G(- 6)A polymorphisms were genotyped by polymerase chain reaction (PCR) in 86 ISH patients and 120 normotensive controls. Plasma angiotensinogen concentration was determined in 198 subjects by an indirect radioimmunoassay technique. Angiotensinogen mRNA concentration was determined by quantitative competitive reverse transcription (RT)-PCR in subcutaneous adipose tissue from a subset of these patients (n = 8) and controls (n = 6). Both the M235T (p = 0.0015) and G(- 6)A (p = 0.029) polymorphisms were associated with ISH. Plasma angiotensinogen concentration was higher in patients than controls (p < 0.0001), but was not associated with genotype. Angiotensinogen mRNA concentration in adipose tissue from ISH subjects was significantly lower than in adipose tissue from normotensive subjects (p = 0.033). The association of angiotensinogen gene variants with ISH and the elevation of plasma angiotensinogen concentration in these patients suggests a role of the angiotensinogen gene in this form of hypertension. Angiotensinogen gene expression may be altered in ISH, but this requires further examination.

Diagnosis and management of unusual dental abscesses in children

Although the majority of dental abscesses in children originate from dental caries or trauma, a few are associated with unusual conditions which challenge diagnosis and management. Recent research findings have shed light on these unusual entities and greatly improved understanding of their clinical implications. These conditions include developmental abnormalities such as dens invaginatus in which there is an invagination of dental tissues into the pulp chamber and dens evaginatus in which a tubercle containing pulp is found on the external surface of a tooth crown. In addition, inherited conditions which show abnormal dentine such as dentine dysplasia, dentinogenesis imperfecta, and osteogenesis imperfecta predispose the dentition to abscess formation. Furthermore, 'spontaneous' dental abscesses are frequently encountered in familial hypophosphataemia, also known as vitamin D-resistant rickets, in which there is hypomineralization of dentine and enlargement of the pulp. In addition to developmental conditions, there are also acquired conditions which may cause unusual dental abscesses,. These include pre-eruptive intracoronal resorption which was previously known as 'pre-eruptive caries' or the 'fluoride bomb'. In addition, some undiagnosed infections associated with developing teeth are now thought to be the mandibular infected buccal cysts which originate from infection of the developing dental follicles. In the present paper, these relatively unknown entities Which cause unusual abscesses in children are reviewed with the aim of updating the general practitioner in their diagnosis and management.

Differences in mouse strain influence leukocyte and immunoglobulin phenotype response to Porphyromonas gingivalis

This study examined the nature of the infiltrating cells in Porphyromonas gingivalis-induced lesions and immunoglobulins in the serum samples of BALB/c (H-2(d)), C57BL6 (H-2(b)), DBA/2J (H-2(d)) and CBA/CaH (H-2(k)) mice. Mice were immunized intraperitoneally with P. gingivalis outer membrane antigens or sham-immunized with phosphate-buffered saline followed by subcutaneous challenge with live organisms 1 week after the final immunization. The resulting skin abscesses were excised 7 days later, cryostat sections cut and an immunoperoxidase method used to detect the presence of CD4(+) and CD8(+) T-cell subsets, CD14(+) macrophages and CD19(+) B cells. Peroxidase positive neutrophils and IgG1- and IgG2a-producing plasma cells were also identified. Anti P. gingivalis IgG1 and IgG2a subclass antibodies were determined in serum obtained by cardiac puncture. Very few CD8(+) T cells and CD19(+) B cells were found in any of the lesions. The percentages of CD4(+) cells, CD14(+) cells and neutrophils were similar in lesions of immunized BALB/c and C57BL6 mice, with a trend towards a higher percentage of CD14(+) cells in sham-immunized mice. The percentage of CD14(+) cells was higher than that of CD4(+) cells in immunized compared with sham-immunized DBA/2J mice. The percentages of CD4(+) and CD14(+) cells predominated in immunized CBA/CaH mice and CD4(+) cells in sham-immunized CBA/CaH mice. The percentage of neutrophils in immunized CBA/CaH mice was significantly lower than that of CD14(+) cells and CD4(+) cells in sham-immunized mice. IgG1(+) plasma cells were more dominant than IgG2a(+) cells in immunized BALB/c, C57BL6 and DBA/2J mice, whereas IgG2a(+) plasma cells were more obvious in sham-immunized mice. IgG2a(+) plasma cells were predominant in immunized and sham-immunized CBA/CaH mice. In the serum, specific anti-P. gingivalis IgG2a antibody levels (Th1 response) were higher than IgG1 levels (Th2 response) in sham-immunized CBA/CaH and DBA/2J mice. In immunized BALB/c mice, IgG2a levels were lower than IgG1 levels, while IgG2a levels were higher in immunized C57BL6 mice. In conclusion, this study has shown differences in the proportion of infiltrating leukocytes and in the subclasses of immunoglobulin produced locally and systemically in response to P. gingivalis in different strains of mice, suggesting a degree of genetic control over the response to P. gingivalis.

Aging per se does not influence glucose homeostasis - In vivo and in vitro evidence

OBJECTIVE - To assess the effect of age on glucose metabolism by examining 1) glucose metabolism in young and middle-aged subjects when total or regional adiposity is taken into account and 2) in vitro glucose transport in adipose tissue explants from young and middle-aged women paired for total and abdominal adiposity. RESEARCH DESIGN AND METHODS - Study 1: body composition, subcutaneous abdominal and visceral adipose tissue areas, and fasting and oral glucose-stimulated glucose and insulin were measured in 84 young and 81 middle-aged men and in 110 young and 91 middle-aged women. Study 2: glucose uptake in subcutaneous abdominal and visceral adipose tissue explants were measured in eight young and eight middle-aged women. RESULTS - Study 1: young and middle-aged men showed similar subcutaneous abdominal tissue area, whereas fat mass and visceral adipose tissue were greater in middle-aged than in young men (P < 0.01). Fat mass and subcutaneous and visceral adipose tissue areas were greater in middle-aged as compared with young women (P < 0.01). Fasting plasma glucose and the glucose response to an oral glucose tolerance test were significantly higher in middle-aged than in young men and women (P < 0.001). Statistical control for visceral adipose tissue area eliminated the difference seen in glucose response in men and women. Study 2: glucose transport in subcutaneous and omental adipose tissue did not differ between young and middle-aged women. CONCLUSIONS - 1) Visceral obesity, more than age per se, correlates with glucose intolerance in middle-aged subjects; 2) aging does not influence in vitro adipose tissue glucose uptake.

Part 1. Growth, carcass and meat quality parameters of male goats: effects of genotype and liveweight at slaughter

Male kids (110) from six goat genotypes, i.e. Boer x Angora (BA), Boer x Feral (1317), Boer x Saanen (BS), Feral x Feral (FF), Saanen x Angora (SA) and Saanen x Feral (SF) and two slaughter weight groups, i.e. Capretto and Chevon (liveweight at slaughter 14-22 and 30-35 kg, respectively) were compared for growth, carcass and meat quality characteristics. Due to their better growth rate, kids from BS and SF genotypes reached the required liveweight for slaughter earlier than kids from other Genotypes used in the study. Chevon kids had a significantly (P < 0.05) lower average daily gain (119 g per day) compared to Capretto kids (171 g per day). SA, SF and FF kids deposited more internal fat in comparison to kids from other genotypes. The dressing percentage of kids ranged from 51 to 54%, with significant differences between genotypes. BS and SF kids had longer carcasses. while BF kids had larger eye muscle area compared to other genotypes. Goat carcasses had a thin subcutaneous fat cover (1.6-2.2 mm). Genotype had a significant (P < 0.05) influence on cooking loss, pigment concentration and muscle colour parameters (CIE L*, a* and b* values). As denoted by the higher V and fibre optic probe values and lower subjective muscle score, the longissimus muscle colour was lighter for BS kids than other genotypes. Cooked meat from the BF kids had lower shear force values and better sensory scores compared to other genotypes. A significant (P < 0.05) decrease in muscle tenderness was observed from Capretto to Chevon carcasses, whereas cooked meat from these two slaughter weight groups was equally accepted (P > 0.05) by the panellists. (C) 2003 Elsevier Science B.V. All rights reserved.

Effects of rosiglitazone and linoleic acid on human preadipocyte differentiation

Background Peroxisome proliferator activated receptor gamma (PPARgamma) is a ligand-activated transcription factor known to be central to both adipose tissue development and insulin action. Growth of adipose tissue requires differentiation of preadipocytes with acquisition of specific cellular functions including insulin sensitivity, leptin secretion and the capacity to store triglyceride. Dietary fatty acids and members of the thiazolidinedione class of compounds have been reported to influence adipogenesis at the transcriptional level. Here, we compare the effects of a dietary fatty acid, linoleic acid, and a thiazolidinedione, rosiglitazone, on biochemical and functional aspects of human preadipocyte differentiation in vitro . Materials and methods Human omental and subcutaneous preadipocytes were subcultured 2-3 times and subsequently differentiated for 21 days in the presence of either linoleic acid or rosiglitazone. Differentiation was assessed using a number of biochemical and functional parameters. Results Omental and subcutaneous preadipocytes differentiated in the presence of linoleic acid showed marked cytoplasmic triacylglycerol accumulation however, no biochemical markers of differentiation (LPL expression, G3PDH gene expression and enzyme activity and leptin expression or secretion) were detected. In contrast, treatment of these cells with rosiglitazone induced full biochemical differentiation as judged by all markers assessed, despite comparatively little lipid accumulation. The rosiglitazone effects were subcutaneous depot-specific. Cells treated with linoleic acid showed decreased glucose uptake cf rosiglitazone-treated cells. A luciferase reporter assay demonstrated that rosiglitazone potently activates h-peroxisome proliferator activated receptor gamma while linoleic acid had no effect. Conclusions These studies demonstrate that (a) human preadipocytes have the potential to accumulate triacylglycerol irrespective of their stage of biochemical differentiation; (b) while omental preadipocytes are refractory to biochemical differentiation in vitro , they are able to accumulate triacylglycerol; and (c) rosiglitazone and linoleic acid may exert their effects via different biochemical pathways.