Search PubMed⌕ Search

Biomedical subjects

R Madrid

Publications and source records attributed to R Madrid.

33 records · Page 2Linked to original sources
PubMed1973

Effects of thallium salts on neuronal mitochondria in organotypic cord-ganglia-muscle combination cultures.

A functionally coupled organotypic complex of cultured dorsal root ganglia, spinal cord peripheral nerve, and muscle has been employed in an experimental approach to the investigation of the neurotoxic effects of thallium. Selected cultures, grown for up to 12 wk in vitro, were exposed to thallous salts for periods ranging up to 4 days. Cytopathic effects were first detected after 2 h of exposure with the appearance of considerably enlarged mitochondria in axons of peripheral nerve fibers. With time, the matrix space of these mitochondria became progressively swollen, transforming the organelle into an axonal vacuole bounded by the original outer mitochondrial membrane. Coalescence of adjacent axonal vacuoles produced massive internal axon compartments, the membranes of which were shown by electron microprobe mass spectrometry to have an affinity for thallium. Other axoplasmic components were displaced within a distended but intact axolemma. The resultant fiber swelling caused myelin retraction from nodes of Ranvier but no degeneration. Impulses could still propagate along the nerve fibers throughout the time course of the experiment. Comparable, but less severe changes were seen in dorsal root ganglion neurons and in central nerve fibers. Other cell types showed no mitochondrial change. It is uncertain how these findings relate to the neurotoxic effects of thallium in vivo, but a sensitivity of the nerve cell and especially its axon to thallous salts is indicated.

Animals↗
PubMedDate not supplied

Effect of early maternal adrenalectomy on antioxidant enzymes, GSH, ascorbate, and uric acid in the rat fetal lung at term.

Previous studies have shown that the increase of the enzymatic antioxidant defense that takes place in the fetal rat lung at the end of gestation can be accelerated by the synthetic glucocorticoid dexamethasone and diminished by metyrapone, a blocker of glucocorticoid synthesis. Since it is known that the fetal adrenal does not start to synthesize corticosterone until the last 20% of gestation, pregnant rats were bilaterally adrenalectomized on the first day of gestation in order to clarify the role of the endogenous maternal hormone on the development of the enzymatic and nonenzymatic antioxidant systems of fetal lung. This early adrenalectomy did not change fetal lung catalase, glutathione peroxidase, glutathione reductase, cytochrome oxidase, GSH, ascorbate, and uric acid at term. The presence of the maternal glands is not essential for lung antioxidant development in the fetus and that the stimulus of fetal corticosterone during the last 20% of gestation is enough to achieve a normal maturation of the fetal lung enzymatic and nonenzymatic antioxidant systems.

Adrenal Glands↗
PubMedDate not supplied

[Percutaneous mitral commissurotomy in patients with mitral valve stenosis and thrombosis of the left atrium].

UNLABELLED: Mitral percutaneous valvotomy (MPV) is an effective therapeutic alternative in the treatment of patients with mitral stenosis (MS) and thrombus in the left atrium have been an absolute contraindication to this procedure. The aim of our study is to evaluate the safety of MPV in patients with MS and thrombus in the appendix of the left atrium (ALA). Between September 1996 and April 1997, we performed ten procedures of MPV with Inoue's technique in patients with MS and thrombus in ALA. Nine females and 1 male were included. Their were 41 +/- 7.6 years old. The Wilkins score in our patients were 8 +/- 1.2. All were treated with oral anticoagulants between three and twelve months but the thrombus did not resolved. With transesophagic echocardiogram and fluoroscopic control we avoided the contact between wires and Inoue's catheter with ALA. Results were positive. Mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.95 +/- 0.3 cm2. There was no case of systemic embolism or others major complications during the MVP and during following one year. CONCLUSION: MPV is a safe and efficient therapeutic alternative in the treatment of selected patients with MS and thrombus in ALA.

Adult↗
PubMedDate not supplied

[Low-molecular-weight heparin in unstable angina pectoris].

We studied the therapeutic effect of standard heparin (HS) compared with low-molecular-weight (HBPM) in two homogeneous groups of 14 patients heparin selected at random, with clinical history and electrocardiographic signs of unstable angina pectoris. Patients received the conventional treatment with platelets' inhibitors, nitrates, adrenergic beta-blockers or calcium antagonists. Both heparins, separately, showed statistical therapeutic effect on the symptoms and signs of unstable angina pectoris. They decreased to zero the number and duration of symptomatic myocardial ischemic events observed by ambulatory electrocardiogram (EKG-Holter). The symptoms of the angina pectoris disappeared at the same elapsed time: in 51.9 +/- 20.2 min. for the HS, and in 48.14 +/- 20.7 min. for the HBPM. They decreased the frequency of the silent myocardial ischemia observed at the EKG-Holter: 9 events decreased to 4 with the HS, and 8 events decreased to 3 with the HBPM. They decreased the total elapsed time of the silent ischemia from 52 min. to 15 min., and the mean elapsed time of the silent ischemia decreased from 3.71 +/- 3.29 min. to 1.07 +/- 1.81 min. with the HS (P < 0.001). With HBPM it decreased the total elapsed time of the silent ischemia from 60 min to 10 min, and the mean elapsed time of the silent ischemia decreased from 4.28 +/- 4.49 min. to 0.71 +/- 1.43 min. (P < 0.02). Both heparins considerably decreased the frequency of the lethal arrhythmias. Although in this study we did not find statistical differences in the therapeutic action of either heparins, HBPM reduced rapidly angina symptoms and the events associated to angina pectoris, cardiac arrhythmias, specially lethal extrasystolia, conduction defects and atrial paroxysmal tachycardia. Compared to HS, HBPM is easily applied, does not produce side effects on coagulation or bleeding time.

Aged↗
PubMedDate not supplied

[Low molecular weight heparin in pregnancy. Report of three cases with pure mitral stenosis].

Three pregnant women with 5 +/- 1.7 weeks of pregnancy and mitral stenosis are described. Their valve area were < 1.0 cm2. They received medical treatment with little improvement and were included in our valvotomy percutaneous mitral (VPM) program with Inoue technique before their 30th week of pregnancy. Before they were treated with low molecular weight heparin (LMWH), Enoxiparin) as prophylaxis of intracavitary thrombus formation transthoracic and transesophageal echocardiogram demonstrated the absence of thrombus. We used 40 mgs. subcutaneous injection once a day during 16 weeks. Repeated transthoracic and transesophageal echocardiogram during VPM showed no evidence of intracavitary thrombus. Complete blood count and coagulation parameters remained within normal limits. The three cases delivered a healthy products. In conclusion, although this series is small, we show that the LMWH can be used in the first trimester of pregnancy as prophylactic treatment instead of oral anticoagulant treatment.

Adult↗
PubMedDate not supplied

[The first myocardial infarct in the elderly patient].

UNLABELLED: Acute myocardial infarction (AMI) in patients over 65 years of age represent more than half of the patients with AMI. Among them, between 60 and 80% represent the first AMI. The objective of this study is to evaluate the behavior of AMI in this group of patients. The clinical charts of patients over 65 years of age with ischemic heart disease admitted into the hospital during the past two years, were reviewed. We used the international criteria (clinical, ECG, enzymatic, echocardiographic and scintigraphic studies) for the diagnosis of AMI. Patients with previous AMI were excluded. We included 274 patients (68% males and 32% females). The age varied from 65 to 91 years with an average of 71.7 +/- 5.3 years. Typical symptoms were present in 90.5% and atypical in 9.5% of the cases, being the latest most frequent in those over 75 years of age. RISK FACTORS: cigarette smoking was present in 60% of the patients, hypertension in 52% and diabetes mellitus in 37%. Both of them were associated in 21%. In 144 cases (52.5%) the MI localization was anterior and in 130 (47.5%) inferior; among them 47 patients (36%) had extension to the right ventricle and 7 (2.5%) had a non Q AMI. COMPLICATIONS: Type I-II VPCs of Bernard Lown were present in 18% and type V 10.2%. Compete AV block in 14.2% (all of them with inferior wall MI); bifascicular block in 55 and mitral insufficiency due to papillary muscle dysfunction in 6.5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Distribution↗
PubMedDate not supplied

[The echo-dobutamine pharmacological stress test in ischemic cardiopathy].

We report our experience with Echo-Dobutamine stress test. In order to evaluate the sensitivity, specificity and the safety, of the pharmacologic echo-dobutamine stress test, we studied 30 patients with ischemic heart disease based on clinical history, 2D echocardiogram, standard exercise stress test and cardiac catheterization. The test was started under continuous videotape of the segmental left ventricular motility on the conventional views. Dobutamine was administer intravenously 2.5 to 40 micrograms/kg/min every 3 minutes, the mean higher dobutamine dose was 19 +/- 14.3 micrograms/kg/min, having a continuous electrocardiographic monitoring of the heart rate as well as blood pressure. The myocardial motility was recorded with each increment in the dobutamine dose. Among the cases, 22 were males and 8 females with an average age of 55 +/- 9 years. Twenty two patients had history of remote myocardial infarction and were asymptomatic at the moment of the test; 8, who had angina pectoris were on a functional class I-II of the CCS. The mean basal ejection fraction was 62.6 +/- 11.7% by echo vs 64.4 +/- 16.8% obtained by cardiac catheterization (p no significant). There were no arrhythmias in any case. The heart rate increased from 68.7 +/- 10.1 to 85.5 +/- 15.7 beats per minute (p < 0.001). The systolic B/P was increased from a mean of 124 +/- 14.5 to 138.3 +/- 14.4 mmHg (p < 0.0005) while the diastolic pressure varied from 82.3 +/- 8.2 to 90.8 +/- 9.6 mmHg (p < 0.001). There were no severe complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Percutaneous transluminal coronary angioplasty. The experience of the Hospital de Especialidades of the La Raza Medical Center, IMSS].

UNLABELLED: We analyzed the initial results of the PTCA program at the Hospital de Especialidades CMR, IMSS. During the last year we studied 33 patients in whom we performed 35 PTCA procedures with total of 45 lesions. The age of the patients varied from 27 to 75 years of age (average 57 year +/- 10.9). Among them, 84.8% were males and 15.2% females. In 54.5% of the patients, stable angina was present, whereas in 45.5% unstable angina was observed. Multivessel disease was detected in 39.4% of the cases. In 17.8% the coronary lesions were type "A", in 77.8% type "B" and in 4.4% type C. The most frequent lesions were present at the left anterior descending artery in 46.6%, right coronary artery in 40% and circumflex in 13.4%. The global procedural success was 88.5% (32/35 procedure) whereas the procedural success by isolated lesion was 88.8% (40/45 lesions). The average artery stenosis was decreased from 85 +/- 10.4% to 23 +/- 16%. A procedural failure occurred in 4 instances (11.4%), among them, 2 (5.71%) without complications and 2 more, associated to acute myocardial infarction. In the present study there were no emergency operation neither deaths. CONCLUSIONS: Although the number of PTCA performed in our hospital is limited, we consider that the initial results are good, with a success rate of 88.5% with a minimal complications.

Adult↗
PubMedDate not supplied

[Thrombolysis in mechanical prosthetic valve thrombosis. Its management with streptokinase].

We present the first experience in Mexico in 10 patients, 9 female and 1 male with an average age of 42.5 years. All patients had clinical, echocardiographic and fluoroscopic criteria of dysfunctioning mechanical valvular prosthesis due to thrombosis (9 Sorin type and 1 Starr-Edwards). None of the patients had contraindications for thrombolytic therapy. All cases were treated with intravenous streptokinase: 250,000 U in 30 minutes followed by an infusion of 100,000 U per hour, always under clinical, echocardiographic and fluoroscopic control every 2 and 24 hours respectively until the normalization of the clinical and hemodynamic parameters with a top limit of 72 hour. The average duration of the thrombolysis was 54 +/- 6.1 hours with an average total doses of 5' 200,000 U of streptokinase. In 90% of the cases there was an increase in the valvular area: mitral (n = 7), from 1.02 +/- 0.21 to 1.75 +/- 0.36 cm2 (p < 0.001), while the mean transvalvular gradient decreased from 10.42 +/- 3.77 to 3.42 +/- 0.975 mmHg (p < 0.001); the systolic pulmonary artery pressure also decreased from 53.7 +/- 15.29 to 35 +/- 2 mmHg (p < 0.001). In the tricuspid prosthesis (n = 2) the average valvular area was increased from 0.8 +/- 0.44 to 1.55 +/- 0.77 cm2, decreasing proportionally the mean transvalvular gradient from 12.5 +/- 2 to 4.5 +/- 3.5 mmHg with no changes in the systolic pressure of the pulmonary artery. In the Starr-Edwards prosthesis in aortic position (n = 1), no hemodynamic changes were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Percutaneous mitral commissurotomy using Inoue's balloon during pregnancy].

The authors present three cases of pregnant women with symptomatic severe mitral stenosis with a mean age of 28.6 +/- 2.3 years, and during 27.6 +/- 1.52 weeks of pregnancy. Two patients were in class III and one in class IV of the New York Heart Association (NYHA). All patients had a mitral valvular area equal or less than 1 cm2, with a Wilkins score of 7 to 9 and mitral insufficiency grade I in two cases; two, had severe pulmonary arterial hypertension (mean > 50 mm Hg). After Percutaneous Mitral Valvuloplasty (PMV) the mitral valve measured by 2D echocardiography increased form 0.83 +/- 0.2 cm2 to 1.8 +/- 0.15 cm2; the mean transmitral gradient diminished from 13 +/- 3.4 mm Hg to 3.6 +/- 1.15 mm Hg; the degree of mitral insufficiency was no modified in neither case. Hemodynamic results revealed increasing of the mitral valve from 0.83 +/- 0.18 cm2 to 2.23 +/- 0.3 cm2; the mean mitral gradient decreased from 21.6 +/- 9 to 4.3 +/- 0.5 mm Hg; the mean left atrial pressure from 30 +/- 12 to 12.3 +/- 4 mm Hg; the mean pressure of the pulmonary artery diminished suddenly from 44.3 +/- 16 to 25.6 +/- 11 mm Hg. The average fluoroscopic time was 15.3 +/- 3 minutes. There were no complications. The patients were discharged 48 hours after the procedure and continued their pregnancies in class I NYHA, which resolved in a non complicated vaginal delivery with normal products. We conclude that PMV is a safe and useful therapy in pregnant patient with severe mitral stenosis refractory to medical treatment.

Adult↗