RESUMEN

Arabidopsis (Arabidopsis thaliana) SPINDLY (SPY) is a putative serine and threonine O-linked N-acetylglucosamine transferase (OGT). While SPY has been shown to suppress gibberellin signaling and to promote cytokinin (CK) responses, its catalytic OGT activity was never demonstrated and its effect on protein fate is not known. We previously showed that SPY interacts physically and functionally with TCP14 and TCP15 to promote CK responses. Here, we aimed to identify how SPY regulates TCP14/15 activities and how these TCPs promote CK responses. We show that SPY activity is required for TCP14 stability. Mutation in the putative OGT domain of SPY (spy-3) stimulated TCP14 proteolysis by the 26S proteasome, which was reversed by mutation in CULLIN1 (CUL1), suggesting a role for SKP, CUL1, F-box E3 ubiquitin ligase in TCP14 proteolysis. TCP14 proteolysis in spy-3 suppressed all TCP14 misexpression phenotypes, including the enhanced CK responses. The increased CK activity in TCP14/15-overexpressing flowers resulted from increased sensitivity to the hormone and not from higher CK levels. TCP15 overexpression enhanced the response of the CK-induced synthetic promoter pTCS to CK, suggesting that TCP14/15 affect early steps in CK signaling. We propose that posttranslational modification of TCP14/15 by SPY inhibits their proteolysis and that the accumulated proteins promote the activity of the CK phosphorelay cascade in developing Arabidopsis leaves and flowers.

Asunto(s)

RESUMEN

OBJECTIVES: To assess the prevalence of abnormal testosterone and gonadotropin values in HIV-infected men before and after 2 years of combination antiretroviral therapy (cART). DESIGN: Multicentre cohort of HIV-infected adults. METHODS: We identified 139 Caucasian antiretroviral-naive male patients who started zidovudine/ lamivudine-based cART that was virologically successful over a 2 year period. Ninety-seven were randomly chosen and plasma hormone determinations of free testosterone (fT) and luteinizing hormone (LH) at baseline and after 2 years of cART were evaluated. RESULTS: At baseline 68 patients (70%) had subnormal fT levels. In these, LH levels were low in 44%, normal in 47% and high in 9%. There was a trend for an association between lower CD4+ T-cell counts and hypogonadism. Most participants had normal FSH levels. No significant changes of fT, LH and FSH levels were observed after 2 years of cART. CONCLUSIONS: Low fT levels, mainly with normal or low LH levels and thus indicating secondary hypogonadism, are found in the majority of HIV-infected men and do not resolve during 2 years of successful cART.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

INTRODUCTION: The present investigation aimed at identifying differences in muscle structural composition, substrate selection, and performance capacity in highly trained endurance athletes as a consequence of consuming a high-fat or a low-fat diet. METHODS: Eleven duathletes ingested high-fat (53% fat; HF) or high-carbohydrate diets (17% fat; LF) for 5 wk in a randomized crossover design. RESULTS: In m. vastus lateralis, oxidative capacity estimated as volume of mitochondria per volume of muscle fiber (HF: 9.86 +/- 0.36 vs LF: 9.79 +/- 0.52%, mean +/- SE) was not different after the two diet periods. Intramyocellular lipid (IMCL) was significantly increased after HF compared with LF (1.54 +/- 0.27% vs 0.69 +/- 0.09%, P = 0.0076). Glycogen content was lower after HF than after LF, but this difference was not statistically significant (487.8 +/- 38.2 vs 534.4 +/- 32.6 mmol x kg-1 dry weight, P = 0.2454). Maximal power and [OV0312]O(2max) (63.6 +/- 0.9 vs 63.9 +/- 1.2 mL O(2) x min-1 x kg-1 on HF and LF) during an incremental exercise test to exhaustion were not different between the two diet periods. Total work output during a 20-min all-out time trial (298 +/- 6 vs 297 +/- 7 W) on a bicycle ergometer as well as half-marathon running time (80 min 12 s +/- 86 s vs 80 min 24 s +/- 82 s) were not different between HF and LF. Blood lactate concentrations and respiratory exchange ratios (RER) were significantly lower after HF than after LF at rest and during all submaximal exercise loads. CONCLUSIONS: Muscle glycogen stores were maintained after a 5-wk high-fat diet period whereas IMCL content was more than doubled. Endurance performance capacity was maintained at moderate to high-exercise intensities with a significantly larger contribution of lipids to total energy turnover.

Asunto(s)

RESUMEN

BACKGROUND: Data on adherence to prescribed medication amongst diabetics are scarce. The purpose of this study was to collect information about the dynamics and patterns of compliance of elderly patients with type 2 diabetes mellitus on oral treatment by using different assessment techniques. METHODS: Adherence to prescribed sulfonylurea medication was prospectively assessed by Self-report (Sr), Pill count (Pc) and using a Medication Event Monitoring System (MEMS) over a period of 2 months in 19 elderly patients with type 2 diabetes mellitus. A pressure-activated microprocessor allowing the registration of each opening is located in the cap of the MEMS drug container. MEMS dosage adherence (MEMSd) was defined as the number of bottle openings divided by the number of doses prescribed), and MEMS regimen adherence (MEMSr) was defined as the percentage of days in which the dose regimen was taken as prescribed. RESULTS: Adherence rates were 96.8 +/- 19.6% for Pc, 92.6 +/- 19.9% for MEMSd and 78.6 +/- 28.3% for MEMSr. Adherence rates for Pc were 103.8 +/- 10.9% in once daily regimens and 87.3 +/- 25.2% in bid/tid regimens (p = 0.0686). MEMSd was 101.0 +/- 4.8% in once daily regimens versus 81.0% +/- 26.8% in bid/tid regimens (p = 0.0255). MEMSr was 93.6 +/- 5.7% in once daily regimens versus only 57.8 +/- 34.1% in bid/tid regimens (p = 0.0031). Assessed by MEMSd as many as 42.1% of the participants had adherence rates greater than 100%. Over-compliance was found primarily in once daily regimens. CONCLUSION: Adherence rates varied with different assessment techniques. Adherence rates were far from optimal. Once daily dosage led to significantly better adherence rates than two or three times daily regimens. However, over-compliance was surprisingly high and occurred more frequently on a once daily regimen.

Asunto(s)