PubMed Health⌕ Search

Biomedical subjects

R Miranda

Publications and source records attributed to R Miranda.

At least 19 recordsLinked to original sources
PubMed1992

Measured vs calculated plasma osmolality in infants with very low birth weights.

OBJECTIVE: To determine the relationship between measured serum osmolality (MsOsm) and calculated osmolality and to examine factors that may affect the osmolal gap. RESEARCH DESIGN: Longitudinal cohort study. SETTING: Regional tertiary neonatal intensive care nursery in a university-affiliated hospital. PATIENTS: Sixty low-birth-weight infants (birth weight, 540 to 1500 g), studied daily during the first week of life. SELECTION PROCEDURE: Consecutive sample. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The MsOsm was significantly higher than the calculated osmolality for the first 6 days of life. The MsOsm was significantly higher during the first 6 days of life in infants with birth weights less than 1000 g than in those with birth weights greater than 1000 g, but the calculated osmolality was similar in both groups. Intraventricular hemorrhage, preservative additives in drugs, and packed red blood cell transfusions did not contribute significantly to osmolal gap or MsOsm. In 19 patients, peak MsOsm was greater than or equal to 320 mmol/kg (mean, 336 +/- 13 mmol/kg; calculated osmolality, 298 +/- 20 mmol/kg; osmolal gap, 38 +/- 19 mmol/kg). Six of these 19 patients died (all with birth weights less than 1000 g). CONCLUSIONS: A significant proportion of patients with very low birth weights (mostly less than 1000 g) have large osmolal gaps and/or an MsOsm greater than 300 mmol/kg during the first week of life. The relationship between increased MsOsm in infants with very low birth weights and effective osmolality requires further study. Therapeutic intervention based solely on elevated MsOsm is ill advised.

Apgar Score↗
PubMed1992

[Eosinophilia and ascites as an expression of a subserous form of eosinophilic gastroenteritis].

Clinical and biological features are discussed on a 50 years old female, who suffered a peritonitis with eosinophilic ascites, together with a bilateral pleural effusion with the same cytologic findings, developing in the course of an hypereosinophilia. The clinical situations in which eosinophilic ascites is associated with blood hypereosinophilia are reviewed. The histopathological findings in this case support the diagnosis of eosinophilic gastroenteritis of subserous type.

Ascites↗
PubMed1991

Laser bronchoscopy.

Explore the source record for details and available documents.

Bronchial Neoplasms↗
PubMed1991

Endoscopic laser surgery. A single-center comprehensive experience.

A retrospective review of endoscopic procedures using the Nd:YAG laser was carried out for patients treated between October 1985 and March 1989. During this 42-month period 165 procedures were performed on 100 patients. The study encompasses a unique period of time in this center, as it includes the initial application, and finally, the time when its use became routine. Indications for laser surgery included the treatment of tumors, bleeding, benign strictures, arterial occlusions, and hemorrhoids. Nd:YAG laser was found to be effective in the treatment of these lesions. The overall success rate was 81 per cent. Patients who are poor surgical candidates would especially benefit from this therapeutic alternative.

Aged↗
PubMed1990

Early developmental exposure to benzodiazepine ligands alters brain 31P-NMR spectra in young adult rats.

Alterations in brain high energy phosphate compounds, using 31P-NMR (nuclear magnetic resonance) spectroscopy, were measured in vivo in young adult (3-4 months) rats following prenatal exposure to ligands acting specifically at benzodiazepine (BDZ) binding sites. The exposure induced a decrease in intracellular pH that indicated a predominant interaction of the drugs in utero with central-type BDZ receptor sites. Late gestational exposure to BDZ ligands also induced changes in brain phosphocreatine (PCr) utilization. Exposure to the lowest dose of DZ (1.0 mg/kg) but not the higher dose (2.5 mg/kg) induced a significant change in PCr utilization. Exposure to the central-type BDZ receptor antagonist RO15-1788 alone clearly altered PCr utilization in adult offspring, and DZ (2.5 mg/kg) when administered concurrently was not able to prevent this effect. Though exposure to a peripheral-type ligand (PK11195) had no effect by itself, it converted the effect of the high dose of DZ to that of the low dose. Together, these results indicate an interaction during development between the central and peripheral-type BDZ binding sites on organization and/or regulation of cellular energy metabolism. Normalized ATP levels were not changed by any prenatal treatment indicating adequate buffering of intracellular ATP by phosphocreatine. The dopaminergic antagonist haloperidol did not alter intracellular pH or any index of phosphate metabolism indicating a selective receptor mediated role for BDZ ligands in influences on the long term organization of intracellular phosphate metabolism.

Animals↗
PubMed1990

[Gastroenteritis with eosinophilia caused by Giardia lamblia].

A case of gastroenteritis due to Giardia lamblia with severe dehydration and complicated with arterial thrombosis, accompanied by eosinophilia and increased serum IgE levels, is presented. The relationship between Giardia and eosinophilia and allergic manifestations is discussed as well as its pathogenesis.

Acute Kidney Injury↗
PubMed1989

Double duodenal webs in an adult.

The duodenal web is an unusual cause of gastric outlet obstruction, but one that must be kept in mind in patients with postprandial nausea, vomiting, and epigastric pain. We suggest endoscopic evaluation of the second and third portions of the duodenum in all such patients. At surgery, direct inspection of the duodenal lumen or the confirmation of its patency by passage of a Foley balloon should be routine. If a duodenal web is encountered, the procedure of choice should be duodenostomy with simple excision of the web.

Adult↗
PubMed1987

Long-acting bromocriptine for the acute treatment of large macroprolactinomas.

Six patients with hyperprolactinemia, visual impairment and large macroprolactinoma were treated with a long-acting bromocriptine, in dosage of 50 mg as a single im injection. All patients underwent a full assessment of pituitary prolactin (PRL) secretion before treatment and the studies were repeated about every week during 40 days. Following bromocriptine injection a rapid amelioration of the clinical and visual defects occurred in all patients. Likewise, a significant reduction of the hyperprolactinemia was documented in all six patients and in three of them serum PRL levels reached values as low as 20 ng/ml, and a tumor size reduction was demonstrated by cranial computerized tomography in three of the six cases. No side effects were associated with the administration of bromocriptine. From this study we conclude that the long-acting bromocriptine represents an additional option for the initial management of large prolactinomas in particular when they are associated with severe visual impairment.

Bromocriptine↗
PubMed1987

HLA antigens associated to amoebic abscess of the liver in Mexican mestizos.

Worldwide prevalence of amoebiasis is estimated at 4 x 10(8) cases/year, yet only one of about 300 individuals harbouring Entamoeba histolytica suffers tissue invasion and these cases are mostly concentrated in certain areas of Asia, Africa and Latin America. Patients with amoebic abscess of the liver (AAL) represent only a small fraction of that. These contrasting figures have been tentatively explained on the one hand through variations in sex, immunocompetence, nutritional and other socioeconomic features of the host, and on the other hand through differences in parasite virulence. In order to explore a possible association between the major histocompatibility complex (MHC) and AAL susceptibility, we studied the HLA profile in 31 Mexican mestizos with AAL and compared it to race and socioeconomically matched controls. Mexican mestizo patients with AAL revealed a significant increase in HLA-Bw16 and HLA-DR3 which could suggest an HLA-related susceptibility to liver invasion by E. histolytica.

Abscess↗
PubMed1986

Characterization of surface roughness in titanium dental implants measured with scanning tunnelling microscopy at atmospheric pressure.

Characterization of the surface topography of implant materials is important for understanding tissue response. We have measured, for the first time, the topography of titanium surfaces used in osseointegrated dental implants. Scanning tunnelling microscopy (STM) which provides 3D real space images was used. In addition to clinical samples, electropolished and anodically oxidized surfaces were also measured. Clinical samples are rather inhomogeneous in character showing grooves and steps with a maximum depth of 0.11 micron. Micropores with an average diameter of about 30 nm are also present. Electropolished samples are rather homogeneous and very smooth, showing steps of 1 to 5 nm in height. The measurements were performed under atmospheric conditions at a resolution in the subnanometer range.

Dental Implantation, Endosseous↗
PubMed1986

Gonadotropin-secreting pituitary adenoma with concomitant hypersecretion of testosterone and elevated sperm count. Treatment with LRH agonist.

Hypersecretion of both FSH and LH was demonstrated in a man with pituitary macroadenoma, who also presented elevated levels of blood testosterone and an increased sperm count. The patient underwent transsphenoidal surgery followed immediately by cranial irradiation. Immunocytochemical analysis of the tumour revealed the presence of FSH, LH, TSH and the alpha-subunit. Gel chromatography of the serum on Sephadex G-100 revealed immunoactive FSH, LH and the alpha-subunit which coeluted with the labelled standards of corresponding hormones. Blood levels of both gonadotropins and testosterone remained persistently elevated up to one year following surgical decompression of the tumour and radiotherapy. It was decided to treat this patient with sc administration of 100 micrograms D-Trp6-LRH biweekly. After 20 weeks, LRH-analogue treatment resulted in the reduction of serum FSH and LH levels and a diminishing in tumour size as assessed by computed tomography scan of the pituitary. This report shows that in a patient with clinically and biochemically documented gonadotropin-secreting adenoma, inducing a state of persistent gonadal hyperfunction, pituitary surgery and cranial irradiation failed to normalize the biochemical abnormality; however, therapy with D-Trp6-LRH agonist induced clinical, biochemical and radiologic improvement.

Adenoma↗
PubMed1979

Immunization of rhesus monkeys with blood-stage antigens of Plasmodium knowlesi.

Evaluation of the efficacy of 3 nonviable blood-stage antigens-schizont Ag, merozoite Ag, and "French press" Ag-of Plasmodium knowlesi, emulsified in Freund's complete adjuvant (FCA), was carried out in a study involving 32 rhesus monkeys. After 2 immunizations, administered 6 weeks apart, monkeys were challenged with a variant of P. knowlesi different from that used for immunization. All 8 control monkeys that received either PBS or FCA developed a severe parasitaemia and died of the infection within 12 days after parasite challenge. In the group that received the freeze-thawed schizont Ag, 5 of the 8 monkeys died at the same time as the controls, 1 died a day later, and 2 survived the infection (maximum parasitaemia: 0.7%; 3.2%). In the freeze-thawed merozoite Ag group, 1 monkey died at the same time as the controls, 5 monkeys died between 14 and 17 days after challenge, and 2 monkeys survived the infection (maximum parasitaemia: <0.01%; 2.7%). In the lyophilized French press Ag group, 2 monkeys died at the same time as the controls, 2 died between 12 and 15 days after challenge, and 4 survived the infection (maximum parasitaemia: 1.2%; 0.4%; 0.9%; 0.07%).Immunized monkeys failed to gain weight during the period of immunization and abscess formation at injection sites was comparable in monkeys of the 3 Ag groups. Reticulocytosis and anaemia developed in all monkeys that survived longer than 12 days after challenge, even in monkeys with very low-grade levels of parasitaemia.Various tests were performed to assess humoral or cell-mediated immune responses during the period of immunization and after challenge. No clear-cut relationship could be established between the results of any of these tests and the survival of immunized monkeys after parasite challenge. Some of the results, however, suggest that there might be some relationship between cell-mediated responses and the survival of immunized monkeys beyond the survival time of control monkeys.

Animals↗
PubMed1979

Concentration and separation of erythrocytes infected with Plasmodium falciparum by gradient centrifugation.

Concentration of infected erythrocytes was achieved in cell suspensions derived from long-term culture of Plasmodium falciparum growing asynchronously in human erythrocytes. This new procedure involves the slow centrifugation (at 33 g) of erythrocyte suspensions through 5% Ficoll solutions. Mature asexual erythrocytic forms are preferentially retained in the gradient solution (top fraction). After further gradient centrifugation of these parasitized cells, the concentration of mature forms is increased 15- to 31-fold and a mature form parasitaemia of 71-81% is obtained in the final erythrocyte suspension. Furthermore, at least 75% of the total number of the mature forms can be retrieved by this method. Parasitized cells that are not retained in the gradient are sedimented to the bottom of the tube (bottom fraction) and consist predominantly of ring forms. Parasites from both the top and bottom fractions are viable and have been used to initiate short-term synchronous cultures. By providing purified parasite preparations, this simple procedure will facilitate immunological, chemotherapeutic, and biochemical studies with P. falciparum.

Cell Separation↗
PubMed1979

Harvest of Plasmodium falciparum merozoites from continuous culture.

Spontaneously released merozoites were harvested from cultures in which 42-90% of the erythrocytes had been infected with mature forms of Plasmodium falciparum at the start of incubation. The mature forms had been extracted from asynchronous cultures by the use of Ficoll and Plasmagel gradients. As the mature forms consisted of both trophozoites and schizonts, merozoites were released into the culture medium over a long period of time. The synchrony of merozoite release did not appear to be improved by prior exposure of parasites to sorbitol. Over this prolonged period of incubation, the yield of merozoites was disappointingly low in cultures containing 2.5% of erythrocytes. At erythrocyte concentrations of 0.01-0.25%, 3-10 times more merozoites were released into the medium; 0.4-2.3 merozoites per initial mature form were harvested over a 15-19-hour period. In addition to merozoites, contents of the culture medium included intact erythrocytes, ghost cells, and other cellular fragments. Only intact erythrocytes were effectively removed from the medium by simple or Ficoll gradient centrifugation. Merozoite preparations that are free from host cellular material are important in the development of a human malaria vaccine.

Animals↗