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M C Morales

Publications and source records attributed to M C Morales.

At least 19 recordsLinked to original sources
PubMed2002

Implication of mitochondria-derived ROS and cardiolipin peroxidation in N-(4-hydroxyphenyl)retinamide-induced apoptosis.

We have studied the effect of N-(4-hydroxyphenyl)retinamide on either malignant human leukaemia cells or normal cells and investigated its mechanism of action. We demonstrate that 4HPR induces reactive oxygen species increase on mitochondria at a target between mitochondrial respiratory chain complex I and II. Such oxidative stress causes cardiolipin peroxidation which in turn allows cytochrome c release to cytosol, caspase-3 activation and therefore apoptotic consumption. Moreover, this apoptotic pathway seems to be bcl-2/bax independent and count only on malignant cells but not normal nor activated lymphocytes.

Antineoplastic Agents↗
PubMed1997

Amelia: analysis of its epidemiological and clinical characteristics.

Eighteen cases of amelia in the Spanish Collaborative Study of Congenital Malformations (ECEMC) were analyzed epidemiologically. Prevalence at birth was 0.15 per 10,000 newborn infants, which is not different from that reported by other authors. Affected females outnumbered males. When compared with the control group, a lower birth weight, shorter gestation, lower placental weight, greater frequency of single umbilical artery, noncephalic presentation at birth, and more frequent maternal vaginal bleeding were observed in amelia cases. There were no significant variations of parental age. None of these patients was exposed to known teratogens, apart from 1 born to a diabetic mother; 3 patients had a genetic condition. Comparison of these variables with other studies is difficult because there is only one study that specifically analyzed amelia. Our data together with previous observations suggest that the genetic basis of amelia might be more important than has been considered previously.

Birth Weight↗
PubMed1997

Gene dosage effect in one family with myoclonic epilepsy and ragged-red fibers (MERRF).

OBJECTIVES: We analyzed the percentage of mitochondrial DNA (mtDNA) heteroplasmy in blood samples of 13 individuals belonging to a three family generation of myoclonic epilepsy with ragged-red fibers (MERRF) and compared the 5 affected patients and the 8 unaffected relatives. MATERIAL AND METHODS: DNA was extracted from blood and muscle of the proband and from blood of 12 maternal relatives. A PCR restriction analysis method was used to detect the mutation. RESULTS: The proband had the complete MERRF phenotype. The phenotype in three other individuals in the maternal lineage was consistent with the MERRF syndrome. The remaining were asymptomatic. The np 8344 mutation was observed in muscle and blood of the proband, and in blood from every one of 12 maternal relatives, ranging from 44% to 83% of mutated genomes. Symptomatic individuals had higher levels (P < 0.001) of mutated mtDNA than asymptomatic maternal relatives. However, high proportions of mutant genomes (up to 63%) were found in asymptomatic relatives. CONCLUSIONS: Although there seems to be a gene dosage effect in MERRF, we found no absolute relationship between the relative proportion of mutant genomes in blood and clinical severity. Factors other than gene dosage in blood may account for the differences in clinical phenotype.

Adult↗
PubMed1996

Self-reported snoring in pregnancy. Association with fetal outcome.

OBJECTIVES: To determine the incidence of self-reported snoring in pregnant compared with nonpregnant women. To compare indicators of fetal outcome in pregnant women with self-reported frequent snoring vs those without snoring. STUDY DESIGN: Prospective, nonrandomized screening and comparison between groups. PATIENTS: Three hundred fifty pregnant women and 110 age-matched nonpregnant women. METHODS: Survey evaluating self-reported snoring. For the pregnant women, infant birthweight, APGAR scores, and other indicators of fetal outcome were obtained by record review. RESULTS: Frequent snoring was reported in 14% of the pregnant women vs 4% of the nonpregnant women (Chi2=6.2; df=1; p<0.05). The pregnant women who reported frequent snoring did not have deliveries resulting in infants with evidence of an increase in compromised outcomes. CONCLUSIONS: Frequent snoring is reported more often in pregnant than in nonpregnant women. Snoring mothers do not appear to be at increased risk for delivering infants with fetal compromise as might be expected with the concomitant occurrence of obstructive sleep apnea.

Apgar Score↗
PubMed1995

Neural tube defects: an experimental model in the foetal rat.

We report on our experience in the experimental induction of Neural Tube Defects (NTD) in the foetal rat by maternal administration of retinoic acid. The teratogen diluted in olive oil was administered in a single intragastric dose (125 mg/kg body weight) to pregnant rats (n = 31) on the 10th day of gestation. Pure olive oil was given to control rats (n = 9). The foetuses were recovered by caesarian section on the 20th day and prepared for morphological investigation. We have studied 201 experimental and 82 control animals. There were NTD in 36.3% of experimental foetuses and none in the control ones. Sacral dysraphism was the most frequent defect but we also observed Arnold Chiari malformations and crowding of the bony limits by an enlarged neural axis. Other associated malformations found were: craneofacial (78.1%), caudal (80%), anorectal (31.4%), and limb defects (89.5%). This simple and inexpensive model may allow us to gain a better knowledge of the biology in the foetus with NTD.

Abnormalities, Drug-Induced↗
PubMed1994

Coronary stenting with a new ultra-short balloon expandable device: early and late animal results.

The early and late effects of a new balloon-expandable coronary stent (Boneau II) were studied in 16 adult mongrel dogs. Thirty-three balloon-expandable stents were deployed using standard transfemoral coronary angioplasty technique. Single stents were placed in eight dogs and multiple (two to four) stents were placed in eight dogs. Intravenous heparin (3,000 units) was administered at the beginning of the procedure. Aspirin, dipyridamole, dextran, and warfarin were not administered before or after the procedure. All stent deployments were successful. Angiographic or pathologic examinations were performed within 24 hr of deployment on two of the dogs, at 2 weeks on two of the dogs, at 2 months on three of the dogs, at 6 months on six of the dogs, and at 1 year on three of the dogs. All successfully deployed stents were noted to be widely patent. There was no evidence of side-branch vessel occlusion. There was no evidence of acute or late vessel thrombosis. Histologic examination at 2 months showed a mean intimal thickness of 153 microns. The stainless steel Boneau II coronary stent is relatively short and easily deployed. This balloon-expandable coronary stent was successfully deployed in normal canine arteries without the use of anticoagulation or antiplatelet therapy before or after the procedure. The Boneau II intracoronary stent has a very low thrombogenic potential in dogs.

Angioplasty, Balloon, Coronary↗
PubMed1993

Decreased erythrocyte Na+,K(+)-ATPase activity associated with cellular potassium loss in extremely low birth weight infants with nonoliguric hyperkalemia.

To determine whether a shift of potassium ions from the intracellular space to the extracellular space accounts, in part, for the hyperkalemia seen in extremely low birth weight infants, we examined potassium concentration in serum and erythrocytes from extremely low birth weight infants with hyperkalemia (n = 12) or with normokalemia (n = 27). In addition, to determine whether the shift of potassium was associated with low sodium-potassium-adenosinetriphosphatase (Na+,K(+)-ATPase) activity, we studied the activity of ATPase in the last 16 infants enrolled in the study. Fluid intake and output were measured during the first 3 days of life. Infants were considered to have hyperkalemia if the serum potassium concentration was 6.8 mmol/L or greater. Blood was obtained daily for intracellular sodium and potassium levels by means of lysis of erythrocytes. The remaining erythrocyte membranes were frozen and analyzed for Na+,K(+)-ATPase activity. There were significantly lower intracellular potassium/serum potassium ratios in the infants with hyperkalemia for each day of the 3-day study (p < 0.001). In the hyperkalemic group, there was lower Na+,K(+)-ATPase activity than in the infants with normokalemia (p = 0.006). Low Na+,K(+)-ATPase activity was associated with lower intracellular potassium/serum potassium ratios (p = 0.006), higher serum potassium values (p = 0.02), and lower intracellular potassium concentration (p = 0.009). The urinary data demonstrated that there was no difference in glomerulotubular balance between the two groups. We conclude that nonoliguric hyperkalemia in extremely low birth weight infants may be due, in part, to a shift of potassium from the intracellular space to the extracellular space associated with a decrease in Na+,K(+)-ATPase activity.

Bilirubin↗
PubMed1993

[Interobserver agreement in reading tuberculin tests].

BACKGROUND: The aim of the study was to evaluate the variability between four observers in the reading of the tuberculin test (TT). METHODS: The study was carried out in the Centro de Salud Mendiguchía Carriche (Madrid) 72 subjects. By direct inspection, four observers read tuberculin determination (skin induration) independently in each subject. To assess variability, the kappa index (K) was calculated. RESULTS: On considering the variable as a dichotomous one, with a cut-off point of 5 mm was 0.88; and of 10 mm, 0.78. Upon considering the index as qualitative in four categories the kappa index in 0 mm was 0.89; in 1-4 mm, 0.24; in 5-9 mm, 0.40 and greater than 9 mm, 0.79. In eight of the subjects studied, the variability observed in reading the test had conditioned further different clinico-epidemiologic attitudes. CONCLUSIONS: The degree of concordance when reading TT is significantly lower at the 1-4 mm and 5-9 mm intervals.

Adolescent↗
PubMed1991

Results of prenatal alcohol exposure on the dimensions and binucleation of cardiac myocytes in neonatal and weanling rats.

Sprague-Dawley rats were exposed to ethyl alcohol in utero. The effect of chronic prenatal exposure was examined by giving mature females alcohol in isocaloric liquid diets which served as the sole source of liquid and caloric intake before mating and throughout gestation. Controls consisted of females maintained on laboratory chow or an isocaloric liquid diet minus alcohol before and during gestation. The offspring were sacrificed at 21 days of age (weanlings) and the hearts dissociated enzymatically to give purified cardiac myocytes. The effects of daily acute prenatal alcohol exposure were studied by gastric intubation of alcohol to chow-fed females for the duration of pregnancy. The doses used approximated 4 and 5 shots of 80 proof liquor per day by a person weighing 150 lb. These offspring were sacrificed at 2, 6, and 21 days postnatal and cardiac myocytes prepared as above. Heart weights were determined and cardiac myocytes were analyzed for cell length, volume, cross-sectional area, and percent binucleation. Additionally, nuclear DNA content was measured in all of the 21 day offspring. Statistical analysis of the data showed no significant differences between hearts exposed to prenatal alcohol and nonexposed controls with either regimen with the exception of percent binucleation which was significantly but only slightly higher in the 6-day-old hearts. These findings are discussed in relation to anatomical heart defects found in patients with full fetal alcohol syndrome.

Aging↗
PubMed1991

Nuclear size and DNA content in rat cardiac myocytes during growth, maturation and aging.

Changes in nuclear volume and DNA content were examined in cardiac myocytes isolated from 21-day-old (weanling, W), 3-month-old (adult, A), and 2-year-old (old, O) rats to document normal parameters for nuclear growth and DNA content. Nuclear volume was calculated from direct measurements of isolated myocyte nuclear profiles and DNA content was measured from DAPI-stained nuclei using an image analysis microdensitometry system. Myocyte volume was measured with a Coulter Channelyzer system. Nuclear volume increased 79% from W to A as a result of an increase in nuclear length. Nuclear width was unchanged. Nuclear volume was not changed from A to O. Approximately 98% of the left ventricular myocytes from all three rat groups contained a diploid DNA content with the remainder of nuclei being tetraploid. The degree of polyploidy increased slightly, but significantly, in right ventricular myocytes from O. Due to the substantially greater increase in myocyte volume relative to nuclear volume, nuclear volume percentage decreased from 3.65 +/- 0.28 to 1.64 +/- 0.13 from W to A but was unchanged from A to O. To summarize: (1) nuclear volume of rat cardiac myocytes increases significantly during normal physiological growth (W to A) but the rate of nuclear growth is less than that of cell volume; (2) the increase in nuclear size from W to A is not due to an increase in DNA content; (3) cardiac myocytes from Sprague-Dawley rats are predominantly diploid; and (4) there is little change in DNA content of cardiac myocytes from rats of this strain during growth, maturation and aging.

Aging↗
PubMed1991

Paradoxically decreased aortic wall stiffness in response to vitamin D3-induced calcinosis. A biphasic analysis of segmental elastic properties in conscious dogs.

We studied the aortic elastic behavior in response to vitamin D3-induced accelerated calcinosis in conscious dogs chronically instrumented with a pressure microtransducer and a pair of ultrasonic diameter dimension gauges in the upper descending thoracic aorta. The two functional phases of the elastic segmental properties of the aorta in vivo were discriminated by computation on a beat-by-beat basis from the phasic pressure-diameter (P-D) hysteresis loops in basal conditions and during the transient state of a wide range of pressures obtained mechanically (aortic occlusion) or pharmacologically (angiotensin bolus). The overall P-D curve formed by all P-D hysteresis loops was comprised of two linear relations according to a model that assumes that only elastin is stretched at lower pressures, whereas both elastin and collagen are stretched at higher pressures. The slope of the first linear portion of the P-D curve was considered as the elastin P-D elastic modulus, and the slope of the curve obtained by subtraction between the P-D curve and the extrapolation of the elastin straight line was assumed to be the collagen P-D elastic modulus. After vitamin D3-induced calcinosis, the elastin elastic modulus was unaffected, whereas the collagen elastic modulus decreased significantly during occlusion maneuvers (58.6%, p less than 0.01) and during bolus injections of angiotensin (37.2%, p less than 0.05). The collagen elastic modulus correlated with the serum calcium concentration (r = -0.65, p less than 0.001) and with the aortic pulse pressure (r = 0.51, p less than 0.01), and this relation persisted at constant heart rate. Histopathologic analysis evidenced calcium-depositing elastic lamina, focal disappearance of collagen, and rupture of elastic fibers. The present study shows that accelerated, severe, experimental calcinosis-inducing calcium deposition inside the large artery walls is accompanied by a clear-cut paradoxical reduction in arterial rigidity that is mainly due to functional and structural modification of collagen elasticity.

Animals↗
PubMed1991

Exercise-related atrioventricular block. Influence of myocardial ischemia.

A 62-year-old woman was noted to have complete heart block immediately following an exercise stress test. Coronary arteriography subsequently revealed a significant lesion in the right coronary artery, which was successfully dilated. Thallium-exercise testing following angioplasty showed no evidence of inducible ischemia and no arrhythmia was seen, supporting the idea that exercise-related heart block may occur secondary to myocardial ischemia.

Angioplasty, Balloon, Coronary↗
PubMed1991

Temporary mechanical circulatory support for severe cardiac failure: experimental study.

We describe a technique for mechanical cardiac assistance in an acute model of severe cardiac failure. Cardiac dysfunction was induced by a high dose of halothane in 13 dogs. Seven served as controls. Following median sternotomy, a pneumatically driven device was implanted in the other six dogs in a para-aortic position, using a simple surgical technique without cardiopulmonary bypass. The aorta was cross-clamped during cardiac assistance. During hemodynamic studies, the seven control animals with induced cardiac failure showed high end-diastolic left ventricular and right atrial pressures with low cardiac index and systolic left ventricular and aortic pressures. All dogs in this group died within 30 minutes. Use of a monovalvular cardiac assist device in the experimental group of six dogs to pump blood from the aortic root to the descending aorta in a counterpulsation manner, confirmed good preservation of systemic hemodynamic parameters after induction of heart failure. All animals in this treated group survived more than 45 minutes. Hemodynamically, the device acts as a new ventricle and the impaired left ventricle functionally becomes a left atrium. This condition is clinically appropriate for recovery of left ventricular function in severe acute myocardial failure.

Animals↗
PubMed1990

Influence of age, growth, and sex on cardiac myocyte size and number in rats.

The effects of altered neonatal nutrition on cardiac myocyte size and number was examined in 21-day-old and 3-month-old rats. Nutritional differences in growth rate were produced in newborns by adjusting litter size to four (fast-growing), eight (normally growing), or 16 (slow-growing) pups per litter. Isolated myocytes were prepared from animals in each group to evaluate changes in cell size and number. Heart weight (mg +/- S.D.), at 21 days of age, was 398 +/- 51 for "fast-growing" rats, 329 +/- 43 for "normally growing" rats, and 228 +/- 24 for "slow-growing" rats. Body weights showed a comparable decline with reduced nutrition. In adults, treatment-related differences in body and heart weight were present in males but not females. "Slow-growing" rats had 21% fewer myocytes than "fast-growing" rats at 21 days of age, a change that persisted in adults. Values for myocyte number from "normally growing" rats were intermediate between those of "fast and slow-growing" rats at both 21 days and 3 months of age. In each heart region of weanling rats, myocyte length and volume were smallest in 16 per litter rats. Cellular dimensions increased progressively with better nutrition.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗