Elevation of serum thrombopoietin precedes thrombocytosis in acute infections

To clarify the mechanisms underlying thrombocytosis secondary to infections, we longitudinally studied serum levels of thrombopoietin (TPO) and interleukin (IL)-6 in 15 infants and young children with prominent thrombocytosis (platelets >700 x 10(9)/l) following acute infections and 116 age-matched controls using an enzyme-linked immunosorbent assay. The subjects included nine patients with bacterial infections, three with viral infections and three with non-determined pathogens. TPO values in the controls were 2.24 +/- 0.87 fmol/ml (mean +/- SD) with a 95% reference interval of 0.85-4.47 fmol/ml. In the first week of infection, platelet counts were normal, but TPO values increased (approximately 10.73 fmol/ml). TPO levels peaked on day 4 +/- 2 at 6.44 +/- 2.37 fmol/ml and then fell gradually. When platelet counts peaked in the second and third weeks, TPO levels were similar to the controls. IL-6 levels in the first week rose and dropped more rapidly than TPO. Serum TPO values were significantly correlated with C-reactive protein levels (r = 0.688, P < 0.001) and IL-6 levels (r = 0.481, P = 0.027). These results suggest that TPO contributes to thrombocytosis following infections in conjunction with IL-6, arguing for additional regulatory mechanisms of blood TPO levels.     

Different effects of pravastatin and cerivastatin on the media of the carotid arteries as assessed by integrated backscatter ultrasound.

BACKGROUND: Currently, there are various types of statins used in the treatment of hyperlipidemia and coronary artery disease. The purpose of this study was to compare the effects of a lipophilic statin (cerivastatin) with those of a hydrophilic statin (pravastatin) on the carotid arterial media using integrated backscatter (IB) ultrasound. Cerivastatin (C) has a strong anti-proliferative effect (APE) on smooth muscle cells (SMCs), whereas pravastatin (P) has a weak effect. METHODS AND RESULTS: The IB values in the media of 72 segments of carotid arteries were measured in 36 patients with hyperlipidemia before and after statin therapy or diet for 6 months (C, n=13: P, n=12: diet, n=11). In addition, IB values of 34 segments of carotid arteries were measured in 34 patients without coronary risk factors. Intima - media thickness (IMT) and arterial stiffness (stiffness beta) were measured by conventional echo at the same time. IB values did not significantly change in the P group (12.8+/-3.5 vs 12.7+/-2.7 dB), but decreased in the C group (12.1 +/-2.9 vs 10.0+/-2.7 dB, p<0.01). Also, stiffness beta did not significantly change in the P group (8.3+/-3.1 vs 7.6+/-2.5), but decreased in the C group (10.1+/-4.3 vs 7.9+/-3.3, p<0.05). IB values correlated with age (r=0.70, p<0.01) and stiffness beta (r=0.67, p<0.01) in the 34 patients without coronary risk factors. CONCLUSIONS: Statin therapy with cerivastatin, but not pravastatin, decreased the IB values of the carotid media and arterial stiffness. The difference between these 2 statins may be related to their effective dose range.     

Longitudinal changes in the well-being of Japanese caregivers: variations across kin relationships

This study examined how the psychological well-being of Japanese caregivers changed over time; it also examined the variation across kin relationships with care recipients. Three interviews over the course of 30 months were conducted with a representative sample of community-dwelling caregivers of frail elderly persons living in a Tokyo suburb. Latent growth modeling demonstrated that mean levels of both depression and emotional exhaustion worsened over time. Change in emotional exhaustion over time showed significant individual variability, whereas change in depression showed little individual variability. Although wife caregivers tended to experience the worst trajectory of emotional exhaustion, daughters-in-law also showed a similar negative trend. The difference in individuals' well-being trajectories by kinship may be explained partly by differences in care recipients' disabilities.     

Identification of quantitative trait loci for cardiac hypertrophy in two different strains of the spontaneously hypertensive rat.

Cardiac hypertrophy and left ventricular hypertrophy are known to be substantially controlled by genetic factors. As an experimental model, we undertook genome-wide screens for cardiac mass in F2 populations bred from the stroke-prone spontaneously hypertensive rats (SHRSP) and normal spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) of a Japanese colony. Two F2 cohorts were independently produced: F2(SHRSP x WKY) (110 male and 110 female rats) and F2(SHR x WKY) (151 male rats). The ratio of heart weight to body weight (Hw/Bw) was evaluated at 12 months of age in F2(SHRSP x WKY) after salt-loading for 7 months, and at around 15 weeks of age in F2(SHR x WKY) who had been fed a normal rat chow diet. Subsequent to an initial screen with 251 markers in F2(SHRSP x WKY) male progeny, 170 and 161 markers were selected and characterized in F2(SHRSP x WKY) female progeny and F2(SHR x WKY) male progeny, respectively. Markers from four chromosomal regions showed suggestive or significant linkage to Hw/Bw. The strongest and the most consistent linkage was found in the vicinity of D3Mgh16 on rat chromosome (RNO) 3 (a maximal log of the odds score reached 4.0 to 6.6 across the F2 populations studied). In the other three regions on RNO6, RNO10 and RNO13, the degree of linkage was more prominent in either males or females. These data provide solid evidence for a "principal" RNO3 quantitative trait loci regulating Hw/Bw in SHRSP and SHR, and also suggest the possible presence of sexual dimorphism in regard to genetic susceptibility for cardiac hypertrophy.