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Biomedical subjects

S Palacios

Publications and source records attributed to S Palacios.

At least 37 records · Page 2Linked to original sources

[Improvement in inspiratory muscle function in patients with mitral stenosis after percutaneous mitral valvuloplasty. Preliminary communication].

BACKGROUND: It has been proved that there is an inspiratory muscle dysfunction in mitral stenosis; Although its causes still remain unknown. AIM: To evaluate the effect of percutaneous balloon mitral valvuloplasty (PMV) on inspiratory muscle performance (IMP) in patients with mitral stenosis (mitral area < 1.5 cm2). PATIENTS AND METHODS: We studied IMP in 8 patients (35 +/- 10 years) before and 3 months after successful PMV. Inspiratory muscle strength was studied by measuring maximal statistical inspiratory mouth pressure (MIP). Endurance was evaluated using a two minute incremental threshold loading test in order to obtain the maximal sustainable inspiratory pressure (SIP), with the maximal sustainable load (MSL) the patients could sustain for 2 minutes. RESULTS: Mitral valvuloplasty increased mean cardiac index from 3.1 +/- 0.3 to 4.15 +/- 0.3 l/min/m2 (p < 0.01), and significantly decreased mean pulmonary and capillary pressures. The MIP value(118 +/- 6 cmH2O), similar to that of normal group, increased to 137 +/- 7 cmH2O (p < 0.01). SIP and maximal sustainable load were 52 +/- 3 cmH2O and 294 +/- 29 g respectively, lower than normal subjects (p < 0.05). They increased after PMV to 80 +/- 3 cmH2O and 463 +/- 26 g respectively (p < 0.001). CONCLUSIONS: PMV improved inspiratory muscle function in patients with severe mitral stenosis, probably secondary to a decrease work of breath and improvement of ventricular function.

Case-Control Studies↗

Current perspectives on the benefits of HRT in menopausal women.

AIMS: Women in the West can now expect to live one third of their life in a postmenopausal state, and consequently in a state of estrogen deficiency. This can have a number of consequences, and many women suffer vasomotor symptoms during the climacteric. Estrogen deficiency can also result in changes to the skin, hair, urogenital, cardiovascular and skeletal systems. This article reviews some of the main actions of replacement estrogen in postmenopausal women, and discusses the major benefits of estrogen replacement therapy (ERT) and hormone replacement therapy (HRT). REVIEW: HRT is well documented to reduce vasomotor symptoms in women suffering from estrogen deficiency, and can have beneficial effects on the skin and the prevention of skin aging. HRT has beneficial effects on urogenitary function including reductions in urinary incontinence and vaginal atrophy. HRT is used as a first-line treatment to prevent or reverse the development of postmenopausal osteoporosis and can reduce the risk of fractures if taken for 5-10 years from the menopause. In epidemiological studies, ERT was associated with a reduction in the risk of coronary heart disease. Estrogens seem to affect the cardiovascular system directly and indirectly such as reducing some of the coronary risk factors. In recent years, estrogen has been linked to beneficial effects in the CNS including an association with a reduction in the risk of developing Alzheimer's Disease. Despite these benefits, HRT compliance remains low, and physicians need to address this if patients are to gain the benefits.

Estrogen Replacement Therapy↗

The deduced primary structure of a ribosomal protein S4 from Trypanosoma cruzi.

Two cDNA clones encoding a protein homologous to ribosomal protein S4 from the protozoan parasite Trypanosoma cruzi were isolated and characterized. Both clones potentially encode for an identical basic protein of 273 amino acids. Sequence comparisons with other species indicate that this protein is highly conserved. Hybridization studies are consistent with the occurrence of two genes in T. cruzi encoding this ribosomal protein. An RNA of approximately 1 kb was present in both exponentially growing and stationary phase derived epimastigotes, and no significant differences were detected in its steady state concentration.

Amino Acid Sequence↗

Changes of the basement membrane and type IV collagen in human skin during aging.

OBJECTIVES: To determine the relationship between skin collagen IV and basement membrane changes during aging, a total of 35 women who had been admitted for surgery, were studied. METHODS: Subjects were arranged into six age-groups (from 35 to 60 years). Skin biopsies were performed in all patients and the samples were taken from a site 6 cm above the pubic symphysis. The collagen IV content and the epithelial basement membrane were analyzed by using immunohistochemical, transmission electron microscopy and computer-assisted image analysis methods. The skin collagen IV content was measured by an image analysis program and expressed in arbitrary units of integrate optical density, and, the basement membrane thickness was expressed in nanometers. RESULTS: Type IV collagen content decreased with age after 35 years (r = -0.9561). The epithelial basement membrane thickness increased significantly with age (r = 0.98192; P < 0.01) and there is an inverse correlation between these two parameters (r = -0.990502). CONCLUSIONS: Although type IV collagen is a basement membrane component and declines with aging, the total thickness of this membrane increases, which suggests a reduction in tissue turnover.

Adult↗

Experimental flail chest: ventilatory function with fixation of flail segment in internal and external position.

UNLABELLED: The effect on ventilatory function of fixation of a flail segment in internal (FIP) and external (FEP) position and oxygen administration was studied in an experimental flail chest with pleural indemnity. Variations of tidal volume (TV), respiratory rate (RR), minute volume (MV), and arterial blood gases are reported. These parameters were measured in nine dogs in control and flail conditions (FC). The effect of FIP, FEP, and oxygen administration were studied. RESULTS: Significant differences were found: TV decreased from control values to FC and from FC to FIP, but increased from FC to FEP. RR values increased from control to FC and from FC to FIP, but decreased from FC to FEP. MV values decreased from FC to FEP. TV, RR, and MV were not changed under oxygen administration. Hypoxemia or hypercapnia were not observed. It was concluded that FIP is deleterious for respiratory mechanics, whereas FEP improves ventilatory parameters.

Animals↗

[Subcutaneous administration of desmopressin to plasma donors: a controlled study].

BACKGROUND: The aim of the present controlled study was to assess the effect of subcutaneous administration of desmopressin acetate (DDAVP) on the yield of Factor VIII (FVIII) and von Willebrand Factor (vWF) obtained in cryoprecipitates after plasmapheresis collection. SUBJECTS AND METHODS: Fifteen plasma donors underwent twice plasmapheresis collections using an "Autophereses C. model A-201" and cryoprecipitates were prepared using standard methods. In every subject of study one of the procedure was performed 35 min after subcutaneous administration of DDAVP (0.3 micrograms/kg), obtained from a highly concentrated preparation of the drug (40 micrograms/ml). Prior to the other apheresis procedure no chemicals were administered. Evaluation of FVIII and vWF levels was performed in peripheral blood samples obtained at different time points and cryoprecipitates product samples. RESULTS: Administration of DDAVP led to two-fold increase the yield of FVIII and vWF immediately before the performance of plasmapheresis. DDAVP stimulation resulted in an increase in the yield of FVIII and vWF in cryoprecipitates, compared with levels in the absence of the drug (703 +/- 53 and 768 +/- 51 U versus 227 +/- 12 and 362 +/- 20 U, respectively). No adverse effects but flushing were observed after DDAVP administration. CONCLUSIONS: Subcutaneous administration of DDAVP prior to plasma collection is a safe method to improve drastically the content of FVIII and vWF in cryoprecipitates. This procedure should be considered as an useful tool to help in providing self-sufficiency of plasma.

Adult↗

Changes in sex behaviour after menopause: effects of tibolone.

In order to analyse both sexual desire after menopause and its response to treatment with tibolone, a randomized placebo/tibolone trial has been designed with 28 postmenopausal patients. They were asked to answer a questionnaire designed by us to obtain quantitative measurements to describe changes in sexual desire. After selection, the patients were randomly assigned to two groups as follows: 14 in the group treated with 2.5 mg/day of tibolone and 14 in the placebo group treated with 500 mg/day of calcium. The patients were monitored after 3, 6 and 12 months. Before joining this study, they had signed a written consent. It was observed that the sexual desire after menopause underwent a significant fall, with decline in arousability and intercourse. The comparative results show that the patients treated with tibolone experience an improvement after the third month of treatment and this improvement was maintained until the end of treatment. We conclude that the questionnaire proposed here is a useful non-parametric method to diagnose a patient's sexuality status at the baseline assessment and a valuable tool for monitoring various therapies. Furthermore, tibolone proved to be effective in managing reduced sexual desire which appears in postmenopausal patients.

Anabolic Agents↗

[Menopause wards].

Explore the source record for details and available documents.

Estrogen Replacement Therapy↗

Antagonism of oestrogen-induced prolactin release by medroxyprogesterone acetate.

Previous studies conducted at our clinic suggested that the administration of hormone replacement therapy (HRT) in postmenopausal women could result in the inhibition of oestrogen-induced prolactin (PRL) release. The aim of this study was to determine how the pituitary function is affected by the sequential addition of medroxyprogesterone acetate (MPA) to oestrogen replacement therapy. Twenty-one postmenopausal women receiving no other medication were treated with a standard dose (0.625 mg/day) of conjugated equine oestrogens (CEE) for a period of 24 days, plus 5 mg/day MPA added sequentially during the last 12 days of the oestrogen therapy. Blood samples were collected before treatment, during oestrogen and oestrogen-progestogen administration and after cessation of treatment. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17 beta-oestradiol (E2) and PRL levels were studied. During treatment gonadotrophin concentrations decreased significantly, while after cessation of HRT the levels of FSH and LH increased. These gonadotrophin fluctuations indicated a sharp rise in E2 levels during therapy and a significant decrease during the treatment-free period. PRL levels were found to be higher during CEE therapy, but they fell when patients received CEE in combination with MPA. These observations suggest that the role of progestogens in a variety of experimental and clinically relevant situations needs to be investigated not only as regards their direct action but also their modulation of the effect of oestrogen.

Climacteric↗

Effects of percutaneous oestradiol versus oral oestrogens on bone density.

In order to compare the effects on bone density of 1.5 mg/day percutaneous 17 beta-oestradiol (E2) and of 0.625 mg/day oral conjugated oestrogens (CEE), 68 women who had undergone hysterectomy were studied. The subjects were randomly allocated to one of three study groups. A total of 15 women dropped out from these groups during the study. The percutaneous group (n = 20) received treatment for 36 months and the oral group (n = 17) for 24 months, while the untreated group (n = 16) served as controls over a period of 24 months. Bone mineral density (BMD) was measured by dual gammagraphic densitometry (Novo 22A densitometer) in the lumbar spine (L2-L4). The percentage gain in the percutaneous group was 1.7% +/- 3.9% after 12 months, 5.6% +/- 2.9% (P < 0.001) after 24 months and 4.7% +/- 3.2% (P < 0.01) after 36 months. In the oral group the gain was 3.5% +/- 13.0% after 12 months and 4.3% +/- 9.2% (P < 0.001) after 24 months. In the untreated group the bone density loss was 6.6% +/- 3.5% (P < 0.001) after 12 months and 9.1% +/- 3.4% (P < 0.001) after 24 months. On the basis of our results we concluded that both 1.5 mg/day percutaneous E2 and 0.625 mg/day oral CEE not only prevented bone loss but also increased BMD, as was confirmed by our findings after 36 and 24 months of treatment, respectively.

Administration, Cutaneous↗

Effects of oestradiol administration via different routes on the lipid profile in women with bilateral oophorectomy.

To determine the influence of various oestrogenenic administrations on lipid response, 63 women with total abdominal hysterectomy and bilateral anexectomy were studied before and 6 and 12 months after receiving 17 beta-oestradiol by different means. The effect on the levels of lipids and lipoproteins of the 2 mg/24 h administration of oestradiol valerate was compared with 1.5 mg/day of percutaneous 17 beta-oestradiol and 0.05 mg/day of transdermic oestradiol. The treatments were given continuously over a year. The oestradiol valerate produced a statistically significant increase (P < 0.05) of the HDL-C levels both after 6 and 12 months (10.6% vs. 11.6%). A significant increase was also observed (P < 0.05) in the Apo AI levels during the treatment (18 and 25%). On the other hand, unfavorable side effects with oestradiol were not produced, either percutaneous or transdermic, on lipid plasmatic or lipoprotein levels. These data show the benefit of oral oestrogenic therapy and the maintenance of the lipid profile in percutaneous and transdermic therapies in oophorectomized women.

Administration, Cutaneous↗

[Percutaneous mitral valvuloplasty and open mitral commissurotomy: comparison of 2 techniques in immediate results].

The aim of this study was to assess the real usefulness of percutaneous mitral balloon valvuloplasty (PMV). Eighty patients aged less than 56 years old, with symptomatic pure mitral stenosis, with an hemodynamic and echocardiographic area < 1.5 cm2, without associated valvular or coronary lesions and without surgical contraindications were studied. These were randomized in two groups of similar age, sex, symptomatology, cardiac rhythm, severity of stenosis and valve anatomy, that were subjected to PMV (n = 38) using a double balloon technique or to mitral commissurotomy (n = 42) with extracorporeal circulation (MC). Mitral areas (calculated using modified Gorlin's formula) increased in 1.15 +/- 0.28 and 1.72 +/- 0.34 cm2 in patients subjected to PMV and MC respectively. No patient died, there was one technical failure with PMV and two patients subjected to MC had a surgical wound infection. Mitral regurgitation increased in more than one degree in two patients treated with PMV (5%) and in 6 patients treated with MC (15%). It is concluded that PMV and MC are highly effective and safe procedures for the treatment of mitral stenosis. Mitral areas obtained with MC are higher than with PMV, however a significant improvement of the disease is achieved with both procedures and MC produces mitral regurgitation with a higher frequency.

Adult↗

[Percutaneous mitral valvuloplasty: immediate and late results in 300 patients].

Between December 1987 and July 1992, we performed a balloon mitral valvuloplasty to 300 patients aged 48 +/- 23 years, with pure or predominant, symptomatic mitral stenosis, with an hemodynamic area < 1.5 cm2 and a mean echocardiographic score of 8.8 +/- 1.3 (6-13). Young subjects with mobile and flexible valves as well as elders with highly damaged valves were included. A transeptal technique employing 2 balloons was used in 97% of cases. There were 3 failures and 9 deficient results. In 284 patients, the procedure was considered successful with a mean increase in mitral area (measured using modified Gorlin's formula) from 0.88 +/- 0.13 to 2.19 +/- 0.38 cm2. Four patients died two due to a left ventricular traumatism, one due to an irreversible low cardiac output and one due to a massive systemic embolism. In five, a cardiac tamponade was treated with pericardiocentesis or surgery. One hundred patients were followed for a mean of 40 +/- 3 months. Mitral areas remained over 1.5 cm2 in 87% and 14 had a significant reestenosis. The latter had an initial echocardiographic score over 8 or previous surgical commissurotomy. Multifactorial analysis identified valvular motility and global echocardiographic scores as predictors of immediate success. Likewise, the last parameter and subvalvular thickening were predictors of late reestenosis and of increase in mitral regurgitation post valvuloplasty. According to our experience, percutaneous balloon mitral valvuloplasty is a first choice therapeutic alternative in patients with mitral stenosis.

Adolescent↗