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Biomedical subjects

A Pereira

Publications and source records attributed to A Pereira.

At least 127 records · Page 7Linked to original sources
PubMed1996

[Echocardiographic evaluation of the aortic and pulmonary valve areas in the newborn infant. Normal patterns].

OBJECTIVES: To determine normal values of the aortic and pulmonary functional valve areas in healthy newborn children. MATERIAL AND METHODS: We prospectively studied 32 newborns (17 boys) who were included in the following criteria: healthy parents, normal pregnancy, eutocic delivery, Apgar index 10 at 5 minutes weight between 2.500 and 4.000 kg, normal physical and echocardiographical examinations. The echocardiographical examination was executed during the first 48 hours of life. We used the continuity equation to calculate the aortic and pulmonary functional valve areas. As a reference we used the anatomic (pi r2) aortic and pulmonary valve areas, calculated in the bidimensional images from the distance measured between the two insertion points of the sigmoid valves. RESULTS: We had echocardiographic images and Doppler registrations of excellent quality, in all the newborn children. The functional pulmonary valve area ranged between 0.30 and 0.50 cm2 (mean +/- SD = 0.41 +/- 0.06) and the anatomical one ranged between 0.29 and 0.49 cm2 (mean +/- SD = 0.49 +/- 0.05), without statistical significance and with a correlation index 0.92. The functional aortic valve area ranged between 0.20 and 0.40 cm2 (mean +/- SD = 0.31 +/- 0.05) and the anatomical ranged between 0.21 and 0.36 cm2 (mean +/- SD = 0.29 +/- 0.05), without statistical significance and with a correlation index 0.91. CONCLUSION: There is a good correlation between the functional aortic and pulmonary valve areas, calculated from the continuity equation, and the anatomical ones. These values will be useful in characterizing the critical stenosis of the newborn child with decreased ventricular function, where the transvalvular gradient is inaccurate in the quantification of the obstruction.

Aortic Valve↗
PubMed1996

[Sleep disturbances in elderly hypertensive patients].

OBJECTIVE: To investigate the subjective and objective perturbations in the elderly hypertensive patients. SAMPLE: 32 individuals were studied with ages > or = 65 years, 14 men and 18 women, with controlled idiopathic high blood pressure, diagnosed over a year ago, and able to lead autonomous lives. METHODS: These outpatients were asked to answer sleep questionnaires adapted from Stanford's questionnaire, and a nocturnal sleep polygraphic register was kept. RESULTS AND CONCLUSIONS: This group of elderly hypertensive outpatients slept badly but never consulted a doctor due to sleeping problems. The most frequent complaints were fatigue, body pains, frequent interruptions of sleep during the night and sleepiness during the day. In the polysonographic register, we highlight insomnia, snoring, obstructive apnea and the periodic movements during sleep. These findings could explain the patient's complaints. Research must be continued on sleep apnea in the elderly hypertensive patients particularly in those with snoring.

Aged↗
PubMed1996

[Identification of a variant D(IVa) with anti-D in serum].

The first D(IVa) variant described so far in Spain is presented. This variant was identified, by means of a commercial monoclonal antibodies panel, in a RhD positive patient with anti-D in her serum. Differential diagnosis is discussed and the clinical relevance of identifying these variants is commented.

Antibodies, Monoclonal↗
PubMed1996

[Amiodarone and the lung].

The pulmonary toxicity induced by amiodarone is one of the major complications that can limit the use of this potent antidysrhythmic agent. The authors perform a bibliographical revision concerning the toxic effects of amiodarone in the lung, pathogenesis, clinical, radiologic and pathologic features, diagnostic problems, risk factors and prognostic data.

Amiodarone↗
PubMed1995

A two-element Enhancer-Inhibitor transposon system in Arabidopsis thaliana.

The Enhancer-Inhibitor (En-I), also known as Suppressor-mutator (Spm-dSpm), transposable element system of maize was modified and introduced into Arabidopsis by Agrobacterium tumefaciens transformation. A stable En/Spm transposase source under control of the CaMV 35S promoter mediated frequent transposition of I/dSpm elements. Transposition occurred continuously throughout plant development over at least seven consecutive plant generations after transformation. New insertions were found at both linked and unlinked positions relative to a transposon donor site. The independent transposition frequency was defined as a transposition parameter, which quantified the rate of unique insertion events and ranged from 7.8% to 29.2% in different populations. An increase as well as a decrease in I/dSpm element copy number was seen at the individual plant level, but not at the population level after several plant generations. The continuous, frequent transposition observed for this transposon system makes it an attractive tool for use in gene tagging in Arabidopsis.

Arabidopsis↗
PubMed1995

Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome: a multivariate analysis of factors predicting the response to plasma exchange.

The aim of this study was to investigate pretreatment prognostic factors that could be useful in predicting the response to plasma exchange in thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS). Thirty-two patients with TTP/HUS, treated with plasma exchange at our institution from 1980 to 1994, were studied. The main clinical and laboratory data at the beginning of plasma exchanges were analyzed by the Cox stepwise logistic regression, applied to either treatment failure or death. Seventeen (53%) patients attained a complete remission and 22 (69%) survived (five in advanced renal failure and long-term hemodialysis). Longer delay in initiating plasma exchanges, presence of stupor or coma, and higher creatinine levels at the beginning of plasma exchanges were independent predictors of treatment failure. Stupor or coma at the beginning of plasma exchanges was the only predictor of mortality from unremitted TTP/HUS. Hemoglobin levels, platelet count, and LDH activity, traditionally envisaged as markers of disease activity, neither correlated with previous duration of TTP/HUS nor had any prognostic value. Early diagnosis of TTP/HUS and prompt initiation of intensive plasma exchange emerged from this study as the most effective interventions for improving the prognosis of TTP/HUS patients.

Adolescent↗
PubMed1995

pBINPLUS: an improved plant transformation vector based on pBIN19.

We describe the construction of a new plant transformation vector, pBINPLUS, based on the popular pBIN19 vector. Improvements over pBIN19 include location of the selectable marker gene at the left T-DNA border, a higher copy number in E. coli, and two rare restriction sites around the multiple cloning site for easier cloning and analysis of T-DNA insertions in plant genomes.

Agrobacterium tumefaciens↗
PubMed1995

Ectopic ACTH syndrome.

Ectopic ACTH syndrome represents a cancer-induced amplification of a property [proopiomelanocortin (POMC) peptides production] normally present in the cells from which the cancer originated but with aberrant posttranslational processing of POMC resulting in a greatly elevated secretion of ACTH precursors. The classic ectopic ACTH-producing tumors described in the 1960s were highly malignant but more recently slowly growing tumors such as carcinoids are reported with increasing frequency. Clinical features of patients with ectopic ACTH were analyzed, including biochemical abnormalities, plasma ACTH, cortisol and urinary steroids. Dynamic tests such as high-dose dexamethasone suppression, metyrapone and ovine-CRH (oCRH) stimulation were explored, as well as inferior petrosal sinus ACTH sampling before and after oCRH. Among the tumor markers examined, elevation of ACTH precursors was uniformly present followed by increased output of calcitonin, gut hormones, oncofetal and placental hormones in decreasing order. Since more than 90% of ectopic ACTH tumors are neuroendocrine in nature exhibiting APUD characteristics, their 2 markers, neuron-specific enolase and chromogranins are very useful. The imaging procedures for localization of the tumor ranged from chest X-rays to computed tomography and magnetic resonance of the chest and abdomen. Abdominal ultrasonography was also useful. Finally somatostatin receptor scintigraphy permitted demonstration of unrecognized tumors and/or metastases, even when the tumors were occult. The ACTH content, immunostaining for APUD markers and altered POMC processing were evaluated in ectopic tumors and/or metastases. Occult ectopic ACTH syndrome of more than 4-6 months of symptoms without the emergence of an obvious source was reviewed. Since the tumors are often clinically and biochemically undistinguishable from pituitary-dependent Cushing's disease, inferior petrosal sinus sampling for ACTH after oCRH stimulation established the diagnosis in over 90% of the cases. 60% of the occult tumors were thoracic carcinoids (3/4 bronchial carcinoids), followed by small cell lung cancer and pancreatic neuroendocrine tumors. In 12% the primary etiology was not detected. The rare syndrome of ectopic CRH syndrome (6 published cases) leading to excessive stimulation of the pituitary which became hyperplastic and secreted excessive amounts of ACTH is discussed. Finally, the 12 published cases and 1 unreported patient with ectopic CRH-ACTH tumors were reviewed, the majority being metastatic small cell lung carcinomas, bronchial and thymic carcinoids.

Adrenal Glands↗
PubMed1995

Molecular characterization of the CER1 gene of arabidopsis involved in epicuticular wax biosynthesis and pollen fertility.

The aerial parts of plants are coated with an epicuticular wax layer, which is important as a first line of defense against external influences. In Arabidopsis, the ECERIFERUM (CER) genes effect different steps of the wax biosynthesis pathway. In this article, we describe the isolation of the CER1 gene, which encodes a novel protein involved in the conversion of long chain aldehydes to alkanes, a key step in was biosynthesis. CER1 was cloned after gene tagging with the heterologous maize transposable element system Enhancer-Inhibitor, also known as Suppressor-mutator. cer1 mutants display glossy green stems and fruits and are conditionally male sterile. The similarity of the CER1 protein with a group of integral membrane enzymes, which process highly hydrophobic molecules, points to a function of the CER1 protein as a decarbonylase.

Amino Acid Sequence↗
PubMed1995

[Growth and development of children with low birth weight at their first birthday].

The aim of this prospective study was to evaluate the effect of low birthweight on growth and development at one year of age, in a cohort of infants born between March 1992 and March 1993 at Hospital de Famalicão. Information was obtained from 199 children, 89 low birthweight cases and 110 born with a normal (> or = 2500 g) weight. The infant mortality rate (56 vs 9 per 1000), the frequency of growth (32% vs 4%, p = 0.0000003) or developmental delay (30% vs 11%, p = 0.002) were significantly higher in low birthweight babies. However, all cases of developmental delay corresponded to minor impairments. At age one, children born with a normal weight presented mean higher values for weight (10.0 +/- 1.1 kg vs 9.2 +/- 1.2 kg; p = 0.000005), length (74.2 +/- 7.1 cm vs 72.9 +/- 3.1 cm, p = 0.0006) and head circumference (46.4 +/- 1.9 cm vs 45.8 +/- 1.6 cm; p = 0.004). Prenatal characteristics such as the planning of the pregnancy, gestational birth weight, diseases during the pregnancy, gestational age or twining, significantly affected development at one year of age, showing that delays can be prevented before a child is born. In addition, post-natal exposures, such as home conditions, energy and nutrient intake, or coping with vaccination schedules and the occurrence of diseases during the neonatal and post-neonatal periods were significantly associated to developmental delay.(ABSTRACT TRUNCATED AT 250 WORDS)

Child Development↗
PubMed1995

[Primary malignant neoplasms of the female genitalia].

A patient with synchronous multiple malignant neoplasms of the female genital tract, involving the ovary, the cervix and the endometrium is described. A 49-year-old patient, presenting pelvic pain and menometrorrhagia over the last six months. An abdominal and speculum examination revealed an abnormal mass occupying the entire left lower quadrant and a vegetating tumor of the cervix, respectively. Microscopic examination of the uterus and ovary revealed a cystadenocarcinoma of the ovary and an adenosquamous carcinoma of the cervix and an endometrioid carcinoma of the endometrium. The data suggests this is a multiple mullerian tumor. Due to treatment and prognostic implications, in the presence of a patient with a tumor involving different organs, we must not overlook differential diagnosis between primary and metastatic tumor.

Carcinoma, Adenosquamous↗
PubMed1995

[Giant aneurysm of the posterior cerebral artery (P3 segment): report of a case].

A rare case of giant aneurysm of the P3 segment of the posterior cerebral artery is presented. The aneurysm was accessed through a combined approach proposed by Sano and the aneurysm was treated by proximal clipping. The patient had a good postoperative recovery without any neurological deficit. The anatomy and the operative approaches are discussed and the neurosurgical literature reviewed.

Cerebral Angiography↗