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Biomedical subjects

J Motta

Publications and source records attributed to J Motta.

16 recordsLinked to original sources

[Radioventriculography during exercise in the diagnosis and management of patients with coronary disease].

We describe the use of exercise radionucleide ventriculography in patients with different probabilities of suffering from ischemic coronary disease. The majority of patients with low probability demonstrated an increase of the ejection fraction and the ones with a high probability a reduction. We describe the utility of this test in the diagnosis, evaluation of the severity and management of patients with coronary disease.

Adult

[Intravenous thrombolytic therapy in acute infarct of the myocardium].

Treatment of acute myocardial infarction with plasminogen activators represents a significant advance in cardiovascular pharmacotherapy. This paper describes the first local treatment experience of myocardial infarction in two patients with intravenous thrombolytic agents. The indications and general aspects of thrombolytic treatment are discussed. Thrombolytic therapy has become standard treatment for some patients with acute myocardial infarction.

Adult

Obstructive sleep apnea and cardiac index.

Seventeen men (age range, 21 to 58 years) with severe obstructive sleep apnea syndrome (OSAS) documented by nocturnal polysomnography underwent hemodynamic investigations during sleep. We studied the evolution of the cardiac index during apneic events in both NREM and REM sleep using the thermodilution technique. Regardless of the patient's age, the sleep state, or the mechanism inducing the OSAS, the cardiac index decreased significantly from baseline during an apneic event and increased significantly from baseline at the resumption of ventilation.

Adult

Sinus arrest during REM sleep in young adults.

Four apparently healthy young adults with vague chest symptoms during the day, two of whom had infrequent syncope while ambulatory at night, had periods of asystole up to nine seconds in duration occurring repeatedly during rapid-eye-movement (REM) sleep. Extensive evaluations, including electrophysiologic studies in two patients, were normal. It is therefore suggested that the underlying pathophysiology involved autonomic dysfunction. REM sleep-related sinus arrests such as these, which may occur in apparently healthy subjects but are undetected, may explain some cases of sudden, unexpected death during sleep. Polygraphic monitoring during sleep may be helpful in delineating the pathophysiology of the sleep-related arrhythmia in persons with daytime cardiac arrhythmias thought to be secondary to abnormal vagal tone. The possibility of nocturnal asystole should be considered in patients such as those described here.

Adult

B5 and B15 associated with progressive Marek's disease, Rous sarcoma, and avian leukosis virus-induced tumors in inbred 15I4 chickens.

RPRL 15I4 inbred chickens are nearly histocompatible except for the B5 and B15 haplotypes that determine the major transplantation antigens. B5B5 and B15B15 15I4 chickens were equally and highly susceptible to tumors induced by Marek's disease, Rous sarcoma, or avian leukosis viruses (ALV), suggesting both of these haplotypes may determine a general influence leading to tumor development. The 15I4 birds were highly susceptible to erythroblastosis, and most developed immunological tolerance to the virus after ALV infection.

Animals

Skin-graft histocompatibility within Regional Poultry Research Laboratory inbred chicken lines.

Skin grafts were exchanged between specific-pathogen-free chicks within the Regional Poultry Research Laboratory (RPRL) inbred lines that are characterized for retrovirus susceptibility and immunogenetic traits. Lines 61 and 63 were histocompatible whereas lines 15I4 and 15I5 were nearly histocompatible. The RPRL Line 7(2) is only histocompatible within families at present, and line 100 has considerable heterogeneity for minor histoantigens. Reaseheath Line C (RH-C) has been established at the RPRL and its histocompatible. Numerous males in lines 6(1), 6(3), 15I4, and RH-C are able to reject female grafts containing the female-specific histoantigen. Two Ea-B alleles in 15I4 previously detected by blood-typing determined rapid skin graft rejection.

Animals

Tests of association of lymphocyte alloantigen genotypes with resistance to viral oncogenesis in chickens. 1. Marek's disease in F7 progeny derived from 6(3) X 15(1) crosses.

Marek's disease (MD)-susceptible progeny of the B5B5 genotype from the F7 generation derived from crosses of Regional Poultry Research Laboratory inbred lines 6(3) and 15(1) were tested for variation in MD resistance associated with the T lymphocyte antigen loci Ly-4 and Th-1. The four double homozygous genotypic classes of Ly-4 and Th-1 were tested in a 2 X 2 design. The Ly-4bb/Th-1aa chickens were significantly more resistant to MD oncogenesis than the other three genotypes. Thus, resistance within B5B5 genotypes appears to be associated with genetic interaction between two T cell antigen loci, which are not linked with the B complex.

Animals

B-haplotype influence on Marek's disease, Rous sarcoma, and lymphoid leukosis virus-induced tumors in chickens.

Experiments were conducted to establish whether B-haplotype genes that determine resistance to RSV-induced tumors would also influence resistance to Marek's disease and lymphoid leukosis. Matings of line 6(3) x 15(1) F3 or F4 breeders segregating for the Ea-B locus antigens that are markers for B2 and B5 haplotypes of the B major histocompatibility complex were made to produce B2B2, B2B5, and B5B5 chicks. The chicks were infected with a standard inoculum of one of the three tumor viruses in separate experiments. The B2 haplotype from 6(3) conveyed greater resistance to tumors induced by all three viruses than the B5 from 15(1) chickens. This finding suggests that some gene(s) in the B-haplotype may determine a general ability to resist tumor formation or cause tumor regression.

Animals

Obstructive sleep apnea syndrome and tracheostomy. Long-term follow-up experience.

Obstructive sleep apnea syndrome (OSAS), a disabling disorder that leads to life-threatening cardiorespiratory events during sleep, has been treated by tracheostomy. This article reports long-term follow-up data of 50 patients who have undergone this procedure, and the indications for surgery are summarized. Surgery may result in secondary local and general acute and subacute complications, but, on a long-term basis, patients were completely relieved of clinical symptoms, returned to full activity, and adapted normally to social and familial life. Temporary closure of the tracheostomy during sleep led to recurrence of obstructive sleep apnea.

Adolescent

Cardiac abnormalities in myotonic dystrophy. Electrophysiologic and histopathologic studies.

Eight young adult male patients with myotonic dystrophy, mean age 26 years, underwent 24-hour Holter electrocardiographic monitoring and intracardiac electrophysiologic study. Right ventricular endomyocardial biopsies were performed at the end of the electrophysiologic study in five of them. The atrial to His[A-H] interval was 155 msec in one case and less than or equal to 55 msec in all patients. Twenty-four hour Holter electrocardiographic monitoring demonstrated more than 4 premature ventricular contractions per minute in two patients and marked cyclical sinus arrhythmia during sleep in two others. Electron microscopic analysis of the endomyocardial biopsy specimens disclosed no prominent sarcoplasmic reticulum abnormalities but prominent I bands compared to previously obtained controls. Myofibrillar degeneration was seen in all cases and was associated with abnormal mitochondria in two. Cardiac abnormalities can be detected very early in the evolution of myotonic dystrophy, even prior to the onset of cardiac symptoms. The reported abnormalities appear closely related to the pathologic process affecting other skeletal muscles.

Adolescent

Respiratory and hemodynamic study during wakefulness and sleep in myotonic dystrophy.

Six young male patients with grade I (mild) myotonic dystrophy and a complaint of excessive daytime sleepiness were studied during wakefulness and sleep. Pulmonary function tests during wakefulness showed evidence of mild abnormality related to respiratory muscle weakness. During sleep, some patients developed a sleep apnea syndrome with high sleep Apnea Indices. There was no relation between hypoxic and hypercapnic ventilatory responses during wakefulness and sleep Apnea Indices. But hypoxemia and hypercapnia worsened considerably during REM sleep. Myotonic dystrophy patients with sleep apnea presented increased pulmonary and systemic arterial pressures during sleep. It was also during sleep that arrhythmias were observed.

Adult

Pericardial effusions in patients with end-stage renal disease.

Echocardiography has greatly increased the accurate recognition of pericardial effusion. Echocardiograms were performed prospectively on the total group of 35 stable asymptomatic patients on chronic haemodialysis to determine the incidence of pericardial effusion. Effusions were shown in 11 per cent (4/35); only 6 per cent (2/35) were estimated as greater than 100 ml. For comparison, records were reviewed retrospectively from 41 haemodialysis patients referred during a 27-month period for echocardiographic assessment of suspected pericardial effusion. These 41 patients came from a total group of 108 patients treated with chronic dialysis over this interval. Of 41 examined, 21 (51%) or 21 of 108 (19%) of the population at risk had an effusion. Of 21 with echocardiographic effusions, 15 (71%), or 15 of 41 (37%) of those with clinically suspected effusion, had more than 100 ml fluid. Gross (greater than 100 ml) pericardial effusions are infrequent in stable, asymptomatic patients with end-stage renal disease. When clinical findings suggest pericardial disease, the echocardiographic demonstration of over 100 ml pericardial fluid is indicative of new effusion, rather than coincidental pre-existing effusion.

Echocardiography

Tracheostomy and hemodynamic changes in sleep-inducing apnea.

Because pulmonary hypertension and systemic hypertension occur during sleep-induced obstructive apnea, six patients underwent overnight hemodynamic monitoring before and after tracheostomy. Variables studied included heart rate, pulmonary artery pressure, femoral artery pressure, and arterial oxygen tension (Po2). After tracheostomy, significant reductions were noted during sleep in mean pulmonary artery pressure from 45 +/- 6 mm Hg (mean +/- SEM) to 22 +/- 2 mm Hg (P less than 0.05) and in mean femoral artery pressure from 137 +/- 6 mm Hg to 97 +/- 3 mm Hg (P less than 0.005). There was also a significant increase for the group in arterial Po2 recorded during the apneic episodes from 38 +/- 3 mm Hg before tracheostomy to 71 +/- 2 mm Hg (P less than 0.001) after tracheostomy. We conclude that tracheostomy improves the hemodynamic abnormalities and hypoxemia that occur during sleep in patients with sleep-induced obstructive apnea.

Adult