Nucleoid-associated PhaF phasin drives intracellular location and segregation of polyhydroxyalkanoate granules in Pseudomonas putida KT2442.

The PhaF is a nucleoid-associated like protein of Pseudomonas putida KT2442 involved in the polyhydroxyalkanoate (PHA) metabolism. Its primary structure shows two modular domains; the N-terminal PHA granule-binding domain (phasin domain) and the C-terminal half containing AAKP-like tandem repeats characteristic of the histone H1 family. Although the PhaF binding to PHA granules and its role as transcriptional regulator have been previously demonstrated, the cell physiology meaning of these properties remains unknown. This work demonstrates that PhaF plays a crucial role in granule localization within the cell. TEM and flow cytometry studies of cells producing granules at early growth stage demonstrated that PhaF directs the PHA granules to the centre of the cells, forming a characteristic needle array. Our studies demonstrated the existence of two markedly different cell populations in the strain lacking PhaF protein, i.e. cells with and without PHA. Complementation studies definitively demonstrated a key role of PhaF in granule segregation during the cell division ensuring the equal distribution of granules between daughter cells. In vitro studies showed that PhaF binds DNA through its C-terminal domain in a non-specific manner. All these findings suggested a main role of PhaF in PHA apparatus through interactions with the segregating chromosome.

Chronic myeloid leukaemia in Spain: Its presentation characteristics have changed. Spanish section of the EUTOS population-based registry. / Leucemia mieloide crónica en España: sus características de presentación han cambiado. Sección española del registro poblacional EUTOS.

OBJECTIVES: To provide more reliable data on the epidemiology of chronic myeloid leukaemia (CML) in Spain than are currently available. MATERIAL AND METHODS: The EUTOS population-based project of European LeukemiaNet is a population registry of new CML cases in patients 18 years of age or older from 22 European areas. The Spanish section included the autonomous communities of Madrid, Castilla-La Mancha and Aragon, from 1-2-2010 to 31-12-2012. RESULTS: A total of 250 cases were recorded in 35 months. The overall incidence was 1.08 cases/10(5) inhabitants-year, with a predominance of men (58%) and clear differences among the communities. The incidence standardised by age was similar (overall, 1.04; men, 1.31; women, 0.81). The median age was 54 years. The incidence increased with age, reaching a peak at>65 years, although 31.7% of cases appeared between the ages of 20 and 44 years. Four percent of cases were diagnosed in advanced stages (2.4% in accelerated phase, 1.6% in blast crisis), 56% were asymptomatic, 38% had splenomegaly, and the Sokal score was high in 11% (lower than what was previously reflected in the literature). CONCLUSIONS: The current incidence of CML in Spain is higher than previously reported and similar to that of the European studies. Unlike the classical descriptions, CML presented mostly in asymptomatic form, with no splenomegaly, less leucocytosis and in stages with better prognosis.

Inhibition by aldosterone of insulin receptor mRNA levels and insulin binding in U-937 human promonocytic cells.

The effect of aldosterone on insulin receptor (IR) expression was investigated in U-937 human promonocytic cells. The putative involvement of the mineralocorticoid receptor (MR) was also analysed. Aldosterone binding assays indicated the presence of MRs with high affinity and limited capacity in these cells. RNA blot assays showed that aldosterone treatment decreased the levels of the two major IR mRNAs (11 and 8.5 kb) present in these cells in a dose- and time-dependent manner. The partial reversal of such a decrease by the mineralocorticoid antagonist spironolactone suggested that MR was involved in the process. Experiments with the RNA synthesis inhibitor actinomycin D indicated that the decrease in IR mRNA content in aldosterone-treated cells was not the result of transcript destabilisation. The inhibitory action of aldosterone was not prevented by the simultaneous presence of the protein synthesis inhibitor cycloheximide, suggesting that the reduction of IR gene expression occurs as a direct response to the action of aldosterone. Furthermore, insulin binding assays showed that aldosterone decreased IR capacity but did not alter receptor affinity. In addition, the IR turnover resulted unaltered. These results provide the first evidence for an in vitro modulation of human IR expression by aldosterone.

[Treatment of the hypertensive response during coronary surgery: comparison of high-dose propofol to propofol with nitroprusside]. / Tratamiento de las respuestas hipertensivas durante la cirugía coronaria: comparación de propofol en altas dosis y propofol asociado con nitroprusiato.

OBJECTIVE: To determine the efficacy of high doses of propofol for controlling hypertension during coronary surgery and to compared cardiovascular stability with propofol to that observed under lower doses of propofol with nitroprusside. PATIENTS AND METHODS: Forty patients were studied prospectively. The patients had good ventricular function and were scheduled for coronary surgery, randomized to two groups. Group P (n = 20) received 0.3 mg/kg propofol plus a 10 mg/kg/h perfusion. Hypertensive responses were treated with boluses of 0.3 mg/kg of propofol and progressive increases in the perfusion dose of 2.5 mg/kg/h at intervals of 2 minutes (maximum 15 mg/kg/h). If hypertension persisted it was treated with nitroprusside. Group N (n = 20) received propofol in perfusion at a dose of 8 mg/kg/h and hypertension was controlled directly with nitroprusside. During extracorporeal circulation, the propofol dose was reduced to 3 mg/kg/h in both groups and was adjusted in response to changes in arterial pressure, with nitroprusside added as needed. We recorded the number of patients becoming hypertensive during sternotomy and mediastinal dissection, the maximum doses of propofol and nitroprusside and the time taken to achieve control of hypertension. Arterial pressure and heart rate were recorded at intervals of one minute throughout the operation. RESULTS: Eight patients in group P and eleven in group N suffered hypertension (NS). Increasing the dose of propofol in group P controlled arterial hypertension in one patient. We found no significant differences between groups in amount of nitroprusside needed or time taken to bring episodes under control. Differences between the two groups in rates of intraoperative hypertension (65% in group P and 85% in group N) and hypotension (75% in group P and 55% in group N) and in duration of episodes were not statistically significant. CONCLUSIONS: Using high doses of propofol rather than moderate doses in combination with nitroprusside in coronary surgery does not improve control of either hypertension or hemodynamic stability.

Stimulation by 1,25-dihydroxyvitamin D3 of insulin receptor expression and insulin responsiveness for glucose transport in U-937 human promonocytic cells.

In the present work, we demonstrate that treatment with 1,25-dihydroxyvitamin D3 for 24 hours increased in a dose-dependent manner the levels of the two major insulin receptor (IR) mRNAs (11 and 8.5 Kb) present in U-937 human promonocytic cells. These levels reached maximum values (1.8-fold 11 Kb; 1.4-fold 8.5 Kb) with the addition of 10(-8) M 1,25-dihydroxyvitamin D3. In these optimal conditions the stimulatory effect of 1,25-dihydroxyvitamin D3 was accompanied by increases in both IR capacity, and insulin responsiveness for glucose transport in these cells. Moreover, such increases appear to be mediated by an enhanced expression of the receptor for 1,25-dihydroxyvitamin D3, measured at the level of both RNA and protein. These results provide evidence of 1,25-dihydroxyvitamin D3 acting as genomic stimulator of the insulin response in the control of glucose transport.

Transcriptional activation of the human insulin receptor gene by 1,25-dihydroxyvitamin D(3).

Treatment with 10(-8) M 1,25-dihydroxyvitamin D(3) for 24 h causes transcriptional activation of the human insulin receptor gene in U-937 human promonocytic cells. The activation seems to potentiate the response to insulin in terms of glucose oxidation. Wortmannin, a phosphatidylinositol 3-kinase inhibitor, causes a greater inhibition of insulin-stimulated glucose oxidation in 1,25-dihydroxyvitamin D(3)-treated cells than in untreated cells. This suggests a stimulation of phosphatidylinositol 3-kinase activity by 1,25-dihydroxyvitamin D(3), which could mediate, at least in part, the potentiation of the insulin response.

Aldosterone impairs insulin responsiveness in U-937 human promonocytic cells via the downregulation of its own receptor.

In an earlier study, we have reported an inhibition of insulin receptor (IR) mRNA levels and insulin binding by aldosterone in U-937 human promonocytic cells. In the present extension of our studies, we demonstrate that this inhibition by aldosterone had no effects on basal glucose transport or on basal thymidine incorporation into DNA, while the cell responsiveness reflected by the maximal response to insulin was decreased by 23% for glucose transport and by 31% for DNA synthesis after the aldosterone treatment. We also prove that this inhibition of the insulin response by aldosterone is mediated by a downregulation of the levels of mineralocorticoid receptors (MRs) (50% decrease) and their mRNA (50% decrease). In addition, the mineralocorticoid antagonist spironolactone reversed the decrease in MR mRNA levels elicited by aldosterone, which suggests the involvement of this receptor in the process.

In vivo tissue specific modulation of rat insulin receptor gene expression in an experimental model of mineralocorticoid excess.

Insulin receptor (IR) gene expression at the mRNA level was investigated in hindlimb skeletal muscle, epididymal adipose tissue and in the liver of rats exposed to prolonged in vivo administration of deoxycorticosterone acetate (DOCA). Following treatment, plasma insulin levels were reduced while glucose levels increased compared to values in control rats. DOCA-treated animals showed an increase in blood pressure and a reduction in body weight. This treatment also induced hypokalemia and decreased plasma protein levels. Sodium levels were unaffected. Moreover, no differences in DNA and protein content or in the indicator of cell size (protein/DNA) were observed in the skeletal muscle or adipose tissue of animals. In contrast, there was a clear increase in the protein and DNA contents of the liver with no change in the indicator of cell size. Northern blot assays revealed 2 major IR mRNA species of approximately 9.5 and 7.5 Kb in the 3 tissues from control animals. DOCA treatment induced no change in the levels of either RNA species in skeletal muscle. However, a decrease of approximately 22% was detected in the levels of both species in adipose tissue whereas the liver showed an increase of 64%. These results provide the first evidence for an in vivo tissue-specific modulation of IR mRNA levels under experimental conditions of mineralocorticoid excess.