Search PubMed⌕ Search

Biomedical subjects

A Munteanu

Publications and source records attributed to A Munteanu.

At least 19 recordsLinked to original sources
PubMed2005

Effects of aldehydes on CD36 expression.

INTRODUCTION: During the oil frying process lipid peroxidation compounds are formed. These products can modulate gene expression and alter cellular behaviour. The cellular uptake of oxidized LDL, a key step in the development of atherosclerosis, is mediated by the CD36 scavenger receptor, whose expression is down-regulated by alpha-tocopherol. OBJECTIVE: To determine the effects of water-soluble aldehydes, obtained from thermally oxidized sunflower oil on the expression of CD36 scavenger receptor in human monocytes (THP-1 cells). We also wanted to study the effects of alpha-tocopherol on CD36 expression in the presence of water-soluble aldehydes. MATERIALS AND METHODS: Sunflower oil was heated in a frying pan, at 180--200 degrees C for 40 min, water-soluble aldehydes were isolated, and the content of thiobarbituric acid reacting substances (TBARS) was determined. THP-1 monocytes were cultured in RPMI medium during 24 h and incubated with increasing concentrations of the water-soluble aldehydes (ranging from 0.05 to 1 microM) and with or without 50 microM of alpha-tocopherol. In parallel, THP-1 cells were cultured with the same volume of an extract obtained from non-oxidized oil or distilled water. The CD36 expression at the cell surface was studied with fluorescence-activated cell sorting (FACS). RESULTS: Monocytes incubated in a medium containing water-soluble aldehydes, showed a dose dependent increase in the expression of the CD36 protein on the cell surface, compared to with the control groups. When the cells were treated simultaneously with 50 microM of alpha-tocopherol a significant reduction in the expression of the CD36 protein was observed. CONCLUSION: Water-soluble aldehydes, extracted from thermally oxidized culinary oil, increase the expression of CD36. This effect is partially decreased by the presence of alpha-tocopherol.

Aldehydes↗
PubMed2004

Ten years of cyclosporine use in renal transplantation: a single-center experience with 479 renal transplants.

INTRODUCTION: From 1983 to 1996 therapy with cyclosporine in association with low-dose azathioprine and prednisone has been used for transplantation immunosuppression. The aim of our study was to present 10 years experience with cyclosporine. MATERIAL AND METHOD: Among 479 renal transplants performed since 1992, 61 were performed with cadaver donor grafts and 58 in pediatric recipients. From 1992 to 1998, the immunosuppressive protocol included CsA, azathioprine, and prednisone. Since 1998, mycophenolate mofetil (MMF) replaced azathioprine. In 2002, tacrolimus and rapamycin were introduced into our protocols. The patients were assessed in terms of serum creatinine, incidence of acute rejection, cyclosporine side effects, and graft and patient survivals. RESULTS: Five-year patient and graft survivals were higher among recipients receiving CsA-MMF-prednisone when compared with CsA-azathioprine-prednisone. The incidence of acute rejection episodes during the first year after transplantation was less frequent among recipients receiving MMF compared to those treated with azathioprine. The overall 5-year survivals for patients was 86.29% and for grafts 74.04%. CONCLUSION: Cyclosporine remains a useful immunosuppressive drug, which represents a major step toward efficient renal transplantation. The availability of multiple effective immunosuppressive agents allows individualized protocols to reduce toxic effects. The advent of new induction regimens offers more opportunities to prolong graft life.

Adult↗
PubMed1999

Wavelet-based lossless compression of coronary angiographic images.

The final diagnosis in coronary angiography has to be performed on a large set of original images. Therefore, lossless compression schemes play a key role in medical database management and telediagnosis applications. This paper proposes a wavelet-based compression scheme that is able to operate in the lossless mode. The quantization module implements a new way of coding of the wavelet coefficients that is more effective than the classical zerotree coding. The experimental results obtained on a set of 20 angiograms show that the algorithm outperforms the embedded zerotree coder, combined with the integer wavelet transform, by 0.38 bpp, the set partitioning coder by 0.21 bpp, and the lossless JPEG coder by 0.71 bpp. The scheme is a good candidate for radiological applications such as teleradiology and picture archiving and communications systems (PACS's).

Algorithms↗
PubMed1999

Wavelet image compression--the quadtree coding approach.

Perfect reconstruction, quality scalability, and region-of-interest coding are basic features needed for the image compression schemes used in telemedicine applications. This paper proposes a new wavelet-based embedded compression technique that efficiently exploits the intraband dependencies and uses a quadtree-based approach to encode the significance maps. The algorithm produces a losslessly compressed embedded data stream, supports quality scalability, and permits region-of-interest coding. Moreover, experimental results obtained on various images show that the proposed algorithm provides competitive lossless/lossy compression results. The proposed technique is well suited for telemedicine applications that require fast interactive handling of large image sets, over networks with limited and/or variable bandwidth.

Algorithms↗
PubMedDate not supplied

Blood coagulation and fibrinolysis in hyperthermic rats.

Exposure of rats to an environment of +40 degrees C that increases central (rectal) temperature to about 40 degrees C, importantly decrease the number of thrombocytes, the blood coagulation (the Quick time and Howel time) and euglobulin lysis time (ELT). In order to search for the mechanism responsible for coagulability and fibrinolysis we studied the relations of these changes with the sympatheticoadrenergic system and with the adrenal hormonal secretion. Some parameters were thus explored after adrenalectomy and under the influence of a beta-blocking agent, Eraldin. Adrenalectomy moderately reduced these decreasing effects, excepting the ELT. Eraldin has a contrary effect. Adrenalectomy acts by suppressing the corticoid reaction and by diminishing the catecholamineones. Since Eraldin influences coagulation and fibrinolysis in an opposite sense than adrenalectomy, it may be concluded that catecholamines do moderate the effect of heating, inhibiting and not stimulating circulation, as assumed. On the contrary, corticoids (gluco- or mineralo-) contribute to the effect, influencing coagulation in hyperthermia. Both influences are slight, not determinant. Supplementary explorations revealed that repeated daily exposure for 1-2 or 3 weeks, simply in the cages in which hyperthermia was subsequently produced, decreased also the number of thrombocites, the QT and the ELT, especially the last one. The HT was less influenced. It results that these exposures, produced effects similar with hyperthermia. Heating rats after these daily repeated exposures does not influence these already changed parameters.

Adrenal Glands↗
PubMedDate not supplied

Blood coagulation and fibrinolysis in rats after hypokinesia and hyperthermia.

Coagulation and fibrinolysis were studied in rats exposed to hypokinesia (HK) obtained by including rats (for 1, 2 and 3 weeks) in small cages designed to limit their movements, permitting only spontaneous feeding (a method widely used for mimicking space flight conditions). The number of thrombocytes, the Quick time, the Howell time and the euglobulinlysis time (ELT) decreased after 1 and 2 weeks of HK; however, after 3 weeks, the parameters of coagulation approached normal control levels, while ELT was still significantly under the control values. An increased blood level of corticosterone in animals subjected to HK suggested that changes observed in the blood coagulation could be linked with it. After exposing rats to heat, similar changes were noticed, i.e. thrombocytopenia and an increase in the speed of coagulation and fibrinolysis. When hyperthermia was induced in hypokinetic animals (after 1 and 2 weeks of HK), the association of exposure to HLK and heat was not followed by a cumulative response.

Animals↗
PubMedDate not supplied

Changes in some digestive enzymes after a seven-day orbital flight.

Changes in some digestive enzymes (amylase, lipase, uropepsinogen) were studied in the serum and urine of one of the participants in the Soviet-Romanian seven-day space flight on the Soyuz 40-Saliut 6 complex. On the first day after landing it was found an increased total serum and urinary amylase, resulting from the separate increase of pancreatic and salivary amylase, determined by Skude and Ihse's method [14]. In both serum and urine, pancreatic amylase was found in higher amounts than the salivary one. Lipase was also increased. These modifications are in general in keeping with those recorded after different flights of similar duration and are part of the anabolic response. The pancreatic and salivary amylase were first investigated separately. Under the same conditions uropepsinogen was decreased, an unexpected result. Serum gastrin was increased, in agreement with a generally increased digestive activity.

Adult↗
PubMedDate not supplied

Retrospective data on the pituitary gland response during immune and neoplastic processes.

A synthesis of many experimental works performed during the last ten years regarding the nonspecific response of the pituitary gland during some immune and neoplastic processes is presented. Different modalities of the response of pituitary gland cell that vary depending on the antigen type were observed. The TAB vaccine inducing a humoral immune response determined an increased secretory activity of STH and FSH cells which are involved by their secretions in the activation of protein synthesis also including antibodies. The tumoral antigens also representing a stressing factor brought about a more intense activity besides the FSH cells, the ACTH and TSH cells.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

The influence of magnetic fields on some humoral parameters and on resistance to hyperthermia in rats.

The influence of magnetic fields of moderate intensities (50 and 120 Oe) was studied in rats after single or repeated exposures with or without a rise in environmental temperature. The following parameters were investigated: the number of erythrocytes and leucocytes, the percentage of different varieties of leucocytes, serum Na+ and K+, plasma corticosterone, ascorbic acid in adrenals, blood catecholamines, plasma fibrinolytic activity, plasma antidiuretic hormone. The resistance to hyperthermia was tested after single exposures to magnetic fields and the survival time was measured. The only significant change recorded in the number of blood cells was a leucopenia after single exposures to 50 Oe for 4 hrs. The parameters indicating the activity of the adrenal cortex were not altered significantly. A moderate rise in blood noradrenaline suggested a possible mild stimulation of the adrenergic system. The plasma fibrinolytic activity was significantly stimulated after single exposures, but no change in fibrinolysis could be recorded after repeated exposures to magnetic fields. Changes observed in plasma ADH were not conclusive. The resistance of animals to hyperthermia - as a general test of reactivity - showed minimal changes in the survival time, loss of weight, and rectal temperature in animals exposed to hyperthermia (40 degrees C) under the influence of the magnetic fields.

Animals↗