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Biomedical subjects

C Reyes

Publications and source records attributed to C Reyes.

At least 37 records · Page 2Linked to original sources

Simple technique for determination of the correct length of percutaneous tunnelled catheters in neonates and children.

A simple technique for determining the correct catheter length in percutaneous tunnelled catheters in infants and young children has been devised that virtually guarantees accurate catheter tip placement. Sixty-six patients, aged newborn to 5 years (mean, 1.6 years) have successfully undergone this technique. It is safe, simple, precise, quick, and cost effective. It requires only a hemostat, a suture, and the supplies provided in the prepackaged catheter kit. This technique should be used whenever a percutaneous technique for accessing the vein is used and fluoroscopy is available.

Anthropometry↗

[Major adverse reactions to propylthiouracil in 586 cases of hyperthyroidism].

Aiming to know the incidence and evolution of major adverse reactions to propylthiouracil in patients with hyperthyroidism, we performed a retrospective analysis of 586 patients treated between 1982 and 1992. All known complications associated to the use of propylthiouracil were considered major adverse reactions, when other causes were discarded. Eight patients (1.4% of the sample) had major adverse reactions: three had agranulocytosis, 3 hepatitis, 1 cholestasis and 1 vasculitis. All had a good evolution after discontinuing the drug. The patients with agranulocytosis were treated with antibiotics and the patient with cholestasis received prednisone. We conclude that major adverse reactions to propylthiouracil are infrequent, that they occur preferentially during the first months of treatment, earlier after reexposure and that there was no associated mortality.

Adolescent↗

Mycobacterium kansasii infection following primary pulmonary malignancy.

The purpose of this study was to determine whether any of the Mycobacterium kansasii cases were the consequences of primary lung malignancy. The records and chest x-ray films of 295 patients with M kansasii pulmonary infection were reviewed. The infection was found to complicate the primary lung neoplasm in four cases. Three patients had had treatment for malignancy: one patient with small cell carcinoma received chemotherapy, steroids and radiation; one with adenocarcinoma underwent a lobectomy and radiation; and the third patient had a lobectomy and radiation for malignant fibrohistiocytoma. The fourth patient developed the infection three years after lung malignancy manifested itself, which was only a few months before the clinical evidence of distant metastasis with adenocarcinoma was detected. We suggest that this infection be considered in patients from M kansasii endemic areas, especially after they have received radiation treatment for lung malignancy. This association has never been described before.

Humans↗

[Catheterization of petrous sinus and selective determination of ACTH: usefulness in the management of Cushing's syndrome in 2 cases].

Two patients with Cushing's syndrome are reported. The syndrome was the consequence of relapse after transphenoidal resection of a pituitary tumor in one and due to occult ACTH secretion in the other. Determination of ACTH after bilateral petrosal sampling in both cases and after systemic venous sampling at different sites in one, allowed localization of the source of hormone secretion which was confined to one side of the hypophysis in one case and to the thorax in the other. Hypophyseal resection in the first case and bilateral adrenal resection in the other were performed successfully. The value of this diagnostic test is analyzed.

ACTH Syndrome, Ectopic↗

Anatomic and functional abnormalities of the esophagus in infants surviving congenital diaphragmatic hernia.

As more infants with congenital diaphragmatic hernia (CDH) survive by means of extracorporeal membrane oxygenation (ECMO), new clinical observations are being made. We report anatomic and functional abnormalities of the esophagus in these infants. Twenty-two of 30 infants with CDH survived. Three of 7 non-ECMO-treated infants and 14 of 17 ECMO-treated infants had an air- or fluid-filled mediastinal mass that was confirmed by an upper gastrointestinal series as ectatic esophagus. Contrast studies demonstrated severe gastroesophageal reflux. Intra-esophageal pH monitoring confirmed significant reflux (Euler scores greater than 50) in 69% of tested patients. Prolonged acid clearance in most patients implied abnormal peristalsis. Hydramnios was correlated to the observed esophageal abnormalities, being present in 13 of 16 infants with an available amniotic history. All patients had symptomatic gastroesophageal reflux managed without antireflux surgery and were discharged 36 +/- 2 days after initiation of feeding. Follow-up (range: 7 to 56 months; mean: 32 months) showed that weight gain in affected children was slower than in those not affected. All but one are asymptomatic. Repeat upper gastrointestinal series shows persistent ectasia but less gastro-esophageal reflux. Gastroesophageal reflux/ectasia is a new observation with CDH. The associated hydramnios may result from proximal foregut obstruction by kinking the gastroesophageal junction with CDH. The radiographic appearance can be quite unusual. Clinical manifestations of gastro-esophageal reflux are manageable without surgery but may account for the observed compromised growth.

Dilatation, Pathologic↗

[Primary hyperparathyroidism: usefulness of high resolution echography in local diagnosis].

Recent reports show a better surgical outcome in primary hyperparathyroidism when an accurate preoperative localization of the lesion in available. We performed high resolution sonography in 23 consecutive patients (20 women) with biochemically proven hyperparathyroidism. Twenty two of them were operated on and their sonographic reports were compared to the surgical and pathological findings (20 adenomas, 1 carcinoma and 1 hyperplasia). One patient did not have surgery but the sonogram was compared to a Tl 201-Tc99 scintigram that suggested an adenoma. Sonography showed a single parathyroid tumor in 17 patients and failed to demonstrate a lesion in six. There were two false positives and 6 false negatives. The sensitivity was 71.5% and the positive predictive value was 88%. Three out of 6 patients with a negative sonography had an adenoma located out of reach for the method. Our results show that the high resolution sonography is a useful, non invasive method to localize abnormally enlarged parathyroid glands in hyperparathyroidism and we think it should be performed in every patient with a biochemical diagnosis of this disease.

Adult↗

[Quantitative morphologic studies of so-called dynamic, eccentric coronary stenoses in cases of acute coronary death].

The residual normal wall segment of an eccentric stenosis of the coronary artery can reduce the residual lumen by spastic contraction of the media. Such dynamic coronary artery stenoses may consequently cause or intensify myocardial ischemia or may lead to sudden coronary death due to dysrhythmia. In 39 cases of sudden coronary death, the histological cross section of extramural coronary arteries were measured by planimetry after postmortem coronary angiography. Of a total of 382 stenoses wit more than 45% narrowing, 178 (48.6%) were of the eccentric kind. These eccentric stenoses of the coronary artery were localized in the RIVA in 48%. On average, 4.5 eccentric stenoses were found in each case of coronary death. Eccentric stenoses with round (49.4) or elliptically situated (35,3%) restenoses was on average 30.5% of the residual lumen wall. The quantitative findings show that the high percentage of eccentric stenoses with a larger normal wall segment is of functional significance with regard to acute coronary deficiency. The morphological description and evaluation of the coronary sclerosis should also take into consideration the kind of stenosis.

Angina Pectoris↗

Extracorporeal membrane oxygenation causes significant changes in intracranial pressure and carotid artery blood flow in newborn lambs.

The effects of ECMO on cerebral dynamics, particularly in the face of asphyxia, are largely unknown. We inquired as to whether carotid artery blood flow (CABF) and intracranial pressure (ICP) were affected by carotid artery/jugular vein ligation, asphyxia, ECMO, and ECMO with asphyxia. Lightly sedated newborn lambs (two to four days old, 3 to 4 kg) in four groups were monitored for mean ICP by an epidural sensor, mean CABF by a flow probe, and mean arterial pressure. Mean values were determined for the duration of each step of the experiment. ECMO was venoarterial at 100 to 120 mL/kg/min. CABF and ICP were measured in group 1 before and after CA/JV ligation; in group 2 during normoxia/normocapnia followed by hypoxia (30 to 40 torr)/hypercapnia (70 to 90 torr); in group 3 before, during, after ECMO while normoxic/normocapnic throughout; and in group 4 as ECMO was begun while hypoxic/hypercapnic. Vessel ligation alone caused no significant CABF/ICP changes. Asphyxia caused physiologic increases in CABF (P less than .03) and ICP (P less than .01). ECMO alone caused a significant decrease in ICP (P less than .003). ECMO with asphyxia caused an even more severe decrease in ICP (P less than .001) combined with augmented CABF (P less than .03). The ICP decrease was limited to the duration of ECMO. Possible explanations include loss of cerebral autoregulation induced by hypoxia/hypercarbia and alterations in cerebral venous drainage necessitated by this method of cardiopulmonary bypass.

Animals↗

Right pneumonectomy syndrome: a lethal complication of lung resection in a newborn with cystic adenomatoid malformation.

A newborn girl underwent a right pneumonectomy for cystic adenomatoid malformation. She subsequently developed compression of the trachea and left mainstem bronchus by a combination of aortic arch, pulmonary artery, and ductus arteriosus. She died while planning aortic suspension, and the anatomic relationships were confirmed by autopsy. This problem is potentially treatable by a variety of means.

Coronary Angiography↗

Selective use of extracorporeal membrane oxygenation in the management of congenital diaphragmatic hernia.

Extracorporeal membrane oxygenation (ECMO) provides lung rest for moribund infants with congenital diaphragmatic hernia (CDH) after deterioration from a "honeymoon" period. This suggests that unstable pulmonary hypertension determines demise more than pulmonary hypoplasia. We avoided treating overwhelming pulmonary hypoplasia by using ECMO only if the premoribund condition had been marked by evidence of adequate lung parenchyma as a best preductal PO2 greater than 100 torr and PCO2 less than 50 torr with maximal therapy. Twenty-six CDH infants with respiratory distress within 4 hours survived operation. Five were not ECMO candidates, with best PO2 33 +/- 9, PCO2 157 +/- 30 torr, and died. Seven honeymoon infants, with best PO2 325 +/- 80, PCO2 27 +/- 5, survived without ECMO. Fourteen additional infants had honeymoon 26 +/- 13 hours with PO2 256 +/- 48, PCO2 30 +/- 8 followed by a-AdO2 gradients 600 torr x 16 +/- 4.5 hours despite maximal therapy. All 14 were treated with ECMO for 48 to 210 hours. Arterial blood gas values at initiation were PO2 34 +/- 6, PCO2 59 +/- 19, and pH 7.22 +/- 0.2. Right-to-left shunting due to pulmonary hypertension was documented by oximetry and two-dimensional echo/Doppler examination. Twelve of 14 (86%) ECMO-treated infants survived with normal arterial blood gas values on room air, no right-to-left shunting, and no gross neurologic sequellae to date. Two of 14 died. Improvement on ECMO was marked by positive hyperoxia response and decreased right-to-left shunting.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbon Dioxide↗

Esophageal dilatation and reflux in neonates supported by ECMO after diaphragmatic hernia repair.

Extracorporeal membrane oxygenation (ECMO) for survivors of surgical repair of congenital diaphragmatic hernia was used in 14 neonates. All showed marked esophageal dilatation on postoperative chest radiographs; the dilated esophagus simulated an air- or fluid-filled mass. All patients were later shown to have marked gastroesophageal reflux as well. The finding suggests a problem in swallowing exists before birth, which may explain the recent correlation between diaphragmatic hernia and hydramnios. The observation of a mediastinal mass in neonates with congenital diaphragmatic hernia may represent esophageal ectasia and may be related to significant gastroesophageal reflux.

Dilatation, Pathologic↗

Phosphorus supplementation of Nellore steers fed Yaragua/Stylo mixture in the Peruvian tropics.

Twenty-four yearling 11-month old Nellore steers initially weighing 180 kg were assigned to three treatments in a randomised complete block experiment lasting 392 days. Animals grazed continuously either Yaragua grass (Hyparrhenia rufa) or Yaragua/Stylo legume (Stylosanthes guianensis) and received the following treatments: A) Control, Yaragua plus common salt, B) Yaragua/Stylo plus common salt, and C) Yaragua/Stylo plus dicalcium phosphate/common salt (1:1). Mineral consumption in the three groups averaged 52 g per animal day-1. At 13 months daily liveweight gains/steer were 0.182, 0.409 and 0.483 kg for treatments of Yaragua, Yaragua/Stylo, and Yaragua/Stylo plus dicalcium phosphate/common salt mixture. Daily liveweight gains per ha were 0.488, 1.289, and 1.522 kg steer-1 for Yaragua, Yaragua/Stylo plus common salt and Yaragua/Stylo plus dicalcium phosphate/common salt. Steers receiving a legume (stylo) in the diet more than doubled weight gains (P less than 0.05) compared to controls with dicalcium phosphate further (P less than 0.05) increasing these gains.

Animal Feed↗

A double-blind trial of metoprolol in acute myocardial infarction. Effects on ventricular tachyarrhythmias.

During a double-blind trial in which patients with suspected myocardial infarction received metoprolol or placebo, we analyzed the occurrence of ventricular tachyarrhythmias. Metoprolol (15 mg intravenously) was given as soon as possible after admission, and thereafter 200 mg was given daily for three months. Antiarrhythmic drugs were given only for ventricular fibrillation and sustained ventricular tachycardia (greater than 60 beats per second). Definite acute myocardial infarction developed in 809 of the 1395 participants, and probable infarction in 162. Metoprolol did not influence the occurrence of premature ventricular contractions or short bursts of ventricular tachycardia. However, there were 17 cases of ventricular fibrillation in the placebo group (697 patients) and only 6 in the metoprolol group (698 patients, P less than 0.05). During the hospital stay significantly fewer patients receiving metoprolol (16) than placebo (38) (P less than 0.01) required lidocaine. In a separate analysis of 145 patients, metoprolol did not influence the occurrence of premature ventricular contractions or short bursts of ventricular tachycardia during the first 24 hours of treatment. Despite a lack of effect on less serious ventricular tachyarrhythmias, metoprolol had a prophylactic effect against ventricular fibrillation in acute myocardial infarction.

Double-Blind Method↗

Effects of prenalterol administered orally in patients with congestive heart failure.

A single-blind study of prenalterol 20-200 mg daily in a slow-release tablet preparation and a placebo was performed in 15 patients with moderate to severe congestive heart failure (NYHA II-IV) to evaluate the haemodynamic and clinical effects of oral prenalterol. Non-invasive parameters in the measurement of cardiac output, stroke volume, pre-ejection period index (PEPI), PEP/LVET ratio, ejection fraction and mean Vcf were significantly improved, indicating beneficial effects of prenalterol on cardiac contractility. Systolic blood pressure, heart rate and rate-pressure product were slightly increased at rest but were considerably lower during exercise. Arrhythmogenecity was not seen in the patients studied. Subjective improvement was noted in the majority of patients as evidenced by a decreased frequency of dyspnoea, fatigue and angina. Unwanted effects, such as palpitations and transmitted arm pulsations, were transient and disappeared with dose adjustment, while the inotropic effect of the medication was maintained. The clinical response appeared to be sustained for up to 2 weeks of treatment, indicating non-development of tachyphylaxis.

Administration, Oral↗

Haemodynamic effects of intravenously administered prenalterol in patients with severe heart failure.

The acute haemodynamic effects of prenalterol 75-225 micrograms/kg i.v. were studied at rest and during exercise in the supine position in 12 patients with chronic congestive heart failure secondary to myocardial infarction (6 pts), chronic valvular disease with valvular replacement (4 pts), ischaemic cardiomyopathy (1 pt) and post myocarditis (1 pt). In 5 of the 6 AMI patients the effect of prenalterol on myocardial oxygen consumption at rest was measured. Pulmonary artery end-diastolic pressure decreased significantly from 17 to 10 mm Hg at rest and from 31 to 21 mm Hg during exercise. Resting heart rate increased from 78 to 90 at rest but was unchanged during exercise. MVO2 in the 5 patients was unchanged or lower in 4 patients and increased in one in whom angina developed after prenalterol. In general, dyspnoea and angina during exercise were less pronounced after prenalterol. The calculated triple product was lower after prenalterol, especially during exercise, indicating lower myocardial oxygen consumption and probably less myocardial ischaemia.

Adrenergic beta-Agonists↗

Glycerine injection and crystal formation in the larynx: a negative study.

Glycerine as a vehicle may be injected alone or with Teflon to reposition a lateral lying paralyzed vocal cord. During the study of a particular patient, crystal formation was observed in laryngeal tissues injected with glycerine. It was hypothesized that glycerine metabolized to oxalic acid crystals via the glyoxylic acid pathway. To confirm this proposition, the gluteus muscle of guinea pigs was injected with glycerine, and at weekly intervals submitted for ordinary and polarized light microscopic examination. The formation of crystals after glycerine injection was not found in the guinea pig. Similarly, no foreign material or crystals were found after centrifuging the stored glycerine.

Animals↗

Acceptability of the contraceptive vaginal ring by rural and urban population in two Latin American countries.

A study of the field acceptability of the Contraceptive Vaginal Ring (CVR) was carried out in rural, small town and urban slum clinics in four locations, two in Brazil and two in the Dominican Republic (D.R.) The CVR was offered as a new method in the clinics and described as similar to the pill but placed in the vagina for three weeks each month with a one-week rest interval. Follow-up surveys were carried out in the four locations at the end of the experimental period. Three, eight, nine and 12.5% of the total acceptors in each of the 4 locations chose the CVR. The acceptance rate fell after the first five months but recovered during the second year. The acceptance rate was much higher in three rual clinics where the nurses themselves used the ring. The follow-up surveys showed that the fact that the ring is placed and kept in the vagina without removal for a prolonged period was the most important attribute of the method and played a large role in women's reactions to it. Anticipated use-related problems were the most prominent reason given by pill users for not choosing the ring, however ease of use was named as the "most killed" characteristic by 55% of ring users. Women tended to remove the ring for intercours and washed it frequently, often with detergents, thus illustrating their concern with "cleanliness" of an object kept within a body cavity for long periods of time.

Brazil↗