Heterochromatin effects on the frequency and duration of LCR-mediated gene transcription

Organ transplantation is associated with an early bone loss that subsequently increases the risk of osteopenia and bone fractures. It is not known whether bone loss continues in long-term survivors, but persistent bone demineralization could further jeopardize an already diminished bone mass. To better define long-term bone status of kidney transplant recipients (KTR), we conducted cross-sectional and longitudinal evaluations of bone mineral density (BMD) in 70 KTR with a mean posttransplantation time of 8.1 years. BMD was determined by dual-energy X-ray absorptiometry and was repeated in 55 of the patients after a mean follow-up period of 22 +/- 5 months. Lumbar and femoral osteopenia, defined as a BMD lower than 2 standard deviations from mean value of sex- and age-matched controls, was present in 28.6% and 10.5% of patients, respectively. There was a significant negative correlation between cumulative prednisone dose and adjusted lumbar as well as femoral BMD (R = 0.45, P < 0.001 and R = 0.29, P < 0.05, respectively). Five patients had a vertebral BMD below a fracture threshold of 0.777 g/cm2. Vertebral fractures (VF) were found in four men and were associated with higher prednisone dosage (P < 0.05), larger cumulative prednisone dose (P < 0.05), and significantly lower BMD values. According to World Health Organization recent criteria for women, prevalences of lumbar and femoral osteopenia and lumbar and femoral osteoporosis in female patients reach 75%, 65%, 33%, and 10%, respectively. The longitudinal part of the study showed a persistent pathological lumbar demineralization process. Over the study period, BMD, expressed as a percentage of that of controls, decreased from 89 +/- 14% to 86 +/- 14% (P < 0.001). Annual change of bone mass was -1.7 +/- 2.8% per year. Accelerated vertebral bone loss (defined as a decrease of BMD, expressed as a percentage of that of controls, of more than 1% per year) was present in 56% of patients and was associated with higher prednisone dosage (P < 0.01). In conclusion, although VF are relatively infrequent in long-term survivors of renal transplantation, osteopenia is a frequent finding, and a substantial proportion of women present lumbar osteoporosis. An ongoing demineralization process of the spine is also demonstrated and probably contributes to long-term spinal osteoporosis incidence. Prednisone dosage remains the most constantly isolated risk factor.     

Management of E. coli dependent factorial diseases in weaning piglets

The most important postweaning factorial diseases are at least partly caused by E. coli. The term postweaning coli complex can be subcategorized into the following manifestations: postweaning diarrhoea, edema disease, postweaning wasting and hemorrhagic gastroenteritis. In the presented study the effect of prophylactic zootechnique alone and zoo- and biotechnique in combination was evaluated during the first weeks postweaning. The results showed that combined zoo- and biotechnique is superior to simple zootechnique regarding food conversion (1.41 kg versus 1.73 kg), average daily weight gain (390 g versus 325 g) and postweaning piglet mortality (3.1% versus 4.9%). It is the opinion of the authors that combined postweaning zoo- and biotechnique should be performed in such pig production units where ETEC and/or SLTEC are present.     

Tyrosine phosphorylation in peripheral lymphocytes from patients with systemic lupus erythematosus

A comparative study of tyrosine phosphorylation was performed on peripheral blood lymphocytes from systemic lupus erythematosus (SLE) patients and from healthy donors. Freshly isolated SLE lymphocytes presented an elevated tyrosine phosphorylation level when compared to healthy donors lymphocytes (p = 0.005). Among all phosphorylated proteins, those called p120, p110, p80 and p55-p60 were more phosphorylated. The level of tyrosine phosphorylation of p120 and p110 proteins discriminated significantly (p = 0.0048, respectively, p = 0.02) between SLE patients and healthy donors. Lymphocytes form SLE patients and healthy donors were then stimulated by cross-linking T cell antigens (CD3, CD4, CD8) to further distinguish the signal transduction between normal and pathologic lymphocytes. No statistical differences in the tyrosine phosphorylation pattern, following CD4 or CD8 cross-linking, were observed between SLE patients and healthy donors lymphocytes. CD3 cross-linking induced an effect on tyrosine phosphorylation different in SLE patients versus healthy donors lymphocytes. Thus, the lymphocytes of SLE patients were refractile in anti-CD3 stimulation in comparison with the healthy donors lymphocytes. Chi-square analysis demonstrated that a significantly larger number of healthy donors responded to anti-CD3 stimulation compared to SLE patients (p = 0.03). The high frequency of tyrosine phosphorylation of p110 and p80 proteins, following CD3 stimulation, in normal versus SLE lymphocytes, suggested that these proteins could be involved in abnormal signal transduction in SLE cells.     

Leiomyomatosis peritonealis disseminata. Two case reports

AIM: To study the action of quercetin (Que) on inhibiting platelet aggregation. METHODS: Active oxygen free radicals produced by xanthine/xanthine oxidase (Xan/XO) reaction was used, platelet aggregation was determined by the turbidimetric method, and the Xan/XO oxyradicals generating reaction by luminol-dependent chemiluminescence (Che) method. RESULTS: Active oxygen free radicals enhanced the platelet aggregation induced by ADP 1.6 mumol.L-1. The rate of maximal aggregation increased from 29%-38% for ADP to 59%-70% for ADP + Xan/XO. The enhancement was abolished by the treatment of platelet-rich plasma (PRP) with Que 650 mumol.L-1 or hydrocortisone (Hyd) 900 mg.L-1. Both Que and Hyd scavenged the active oxyradicals in vitro. The Che was decreased by 75.7% (Que 4 mumol.L-1) and 79.0% (Hyd 900 mg.L-1) as compared with control. CONCLUSION: Active oxygen free radicals participated in the platelet aggregation, and scavenging oxyradicals by Que was one of mechanisms of inhibiting platelet aggregation.     

Mechanical behavior of double-aged AA8090

The short-transverse fracture toughness of AA8090 is dramatically improved by double aging treatments, which produce a transition from coarse planar slip to homogeneous deformation. Although the fracture mode remains intergranular, stress concentrations across the weak, highangle boundaries are reduced by homogeneous deformation, ultimately increasing fracture toughness. This behavior is attributed to dissolution of the shearable phase(δ’) and growth of the strong precipitate (S’). Predictions of slip distribution agree fairly well with observed deformation behavior. A number of tempers with improved strength-toughness relationships were developed, and fatigue crack growth behavior in laboratory air was not affected by double aging.     

Familial jejunal atresia with renal dysplasia

Although jejunal atresia occasionally may occur with a familial pattern, an association with renal disease has not been described. The authors report on three family members treated over two generations, all of whom had both proximal jejunal atresia and renal dysplasia. This association was most likely inherited as an autosomal dominant trait.     

Effects of observer metamerism in the determination of human color-matching functions

This article addresses the results of the recent North and Fairchild article on observer metamerism. It reports on the results of a different experiment that produced similar results to those of North and Fairchild. The history of observer metamerism is outlined briefly and some possible sources of the large variations in inter-observer matches are suggested. Finally, a plea for a commercially viable special index of metamerism for change in observer is formulated. © 1995 John Wiley & Sons, Inc.