The chromogen 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS.+) can be directly generated by the enzymatic system formed by hydrogen peroxide and horseradish peroxidase in ethanolic media. The reaction is time- and concentration-dependent, and the ABTS.+ generated shows excellent stability. The method is an adaptation of the decolouration method previously reported (Cano et al. 1998. Phytochem Anal 9:196-202), which was used for estimating anti-oxidant activity in aqueous media. When the assay described here was used to quantify the anti-oxidant activity of two anti-oxidants, Trolox (an analogue of vitamin E) and beta-carotene, the latter had 2.5 times better anti-oxidant capacity than Trolox at the same concentration. The free radical quenching activity (anti-oxidant activity) of leaf pigment extracts was measured and related to the the carotenoid contents in leaf extracts of barley, oat and citrus. The possibilities of using this experimental approach to evaluate the status of photoprotective pigments are discussed.

Avena↗

PubMedDate not supplied

Replicative senescence, aging and growth-regulatory transcription factors.

Normal somatic cells invariably enter a state of permanent growth arrest and altered function after a finite number of divisions. This phenomenon is termed cellular or replicative senescence. Replicative senescence is thought to be a tumor-suppressive mechanism, and a contributing factor in aging. Three features distinguish senescent from presenescent cells: an irreversible block to cell proliferation, increased resistance to apoptotic death, and changes in differentiated functions. Senescence entails an altered pattern of gene expression, much of which is due to altered transcription. At least three growth regulatory transcriptional modulators are repressed in senescent cells: the c-fos component of the AP1 transcription factor, the Id1 and Id2 helix-loop-helix (HLH) proteins that negatively regulate basic HLH transcription factors, and the E2F-1 component of the E2F transcription factor. Failure to express any one of these modulators is very likely sufficient to arrest cell proliferation. Loss of these modulators may also explain many of the functional changes shown by senescent cells. In the case of c-fos repression, the resulting decline in AP-1 activity may be exacerbated by an altered ratio of AP-1 components to a protein known as QM or Jif. QM interacts with the c-jun component of AP-1 and suppresses AP-1 activity. We cloned QM from a senescent fibroblast cDNA library, and found that it was neither cell cycle- nor senescence-regulated. However, QM suppressed the growth of murine and human fibroblasts when overexpressed. Thus, an altered balance between positive factors (e.g., AP-1 components) and negative factors (e.g., QM) may lead to the growth arrest, as well as the changes in differentiated gene expression, that are a hallmark of senescent cells.

Carrier Proteins↗

PubMedDate not supplied

[Aortic valve replacement by a pulmonary homograft].

Minor experience still exists in our country with regard to the use of valve homografts in cardiac surgery. Only a few implantations have been performed in cases of right ventricular outflow tract reconstruction in addition to our own experience in cases of infective endocarditis of the aortic valve. We present a case of aortic valve replacement by using an antibiotic-sterilized fresh pulmonary valve autograft. The case is described and the possible advantages of the use of pulmonary allografts in the aortic position are discussed.

Adult↗

PubMedDate not supplied

[Ascending thoracic aorta-supraceliac abdominal aorta by-pass in a patient with coarctation and partial hypoplasia of the arch and aortic isthmus].

A twenty years old patient, with arterial hypertension at the right arm and absent pulse in both lower extremities was studied by angiography, and a coarctation of aortic arch with partial hypoplasia of aortic arch and aortic isthmus was found. Patient underwent to a surgical operation and, by anterior approach, an ascending thoracic aorta-supraceliac abdominal aorta by-pass was made. In the present case report, advantages, indications and experience with such by-pass modality are review.

Adult↗

PubMedDate not supplied

Is glucose self-monitoring beneficial in non-insulin-treated diabetic patients? Results of a randomized comparative trial.

To study if self-monitoring of glucose, urinary or capillary, could help them to improve their metabolic control through better compliance to diet and/or hypoglycaemic agents, 208 non-insulin-treated poorly controlled diabetic patients were randomized to: group A--regular HbA1c determinations but no self-monitoring, group B--self-urine glucose monitoring, twice every other day, group C--self blood glucose monitoring, twice every other day, and followed six months. At the end of the study period, the decrease of HbA1c over six months--main endpoint--was not significantly different between the three groups (mean +/- SEM; group A: -0.5 +/- 0.2%; group B: -0.1 +/- 0.3%; group C: -0.4 +/- 0.3%). However, the degree of compliance to blood glucose self-monitoring in group C appeared to relate to the outcome: a significant correlation was found between the number of blood glucose strips used and the decrease of HbA1c (r = .36, p less than .02). We conclude that regular self-monitoring has no definite advantage over the usual management for improving metabolic control in non-insulin-treated diabetic patients, though it may possibly help patients ready to comply with its use.

Aged↗

PubMedDate not supplied

[New approach to the teaching of microbiology and parasitology].

Explore the source record for details and available documents.

Colombia↗

PubMedDate not supplied

Epidural hematoma after epidural anesthesia in a patient with peripheral vascular disease. Case report.

BACKGROUND AND OBJECTIVES: Epidural hematoma is a severe, uncommon complication associated with epidural anesthesia in patients with peripheral vascular disease who require anticoagulant therapy. METHODS: An 84-year-old woman with acute left leg arterial ischemia underwent revascularization surgery under lumbar epidural anesthesia. Pre- and postoperative heparin was administered as an anticoagulant. RESULTS: Reperfusion of the leg was successful, however, 3 days later clinical signs of spinal cord compression appeared and epidural hematoma was diagnosed. Neurologic recovery was poor. CONCLUSIONS: This case highlights the need for careful individual preoperative analysis and postoperative observation to make anesthetic practice safe in patients receiving perioperative anticoagulant therapy.

Aged↗