Biomedical subjects

D Cuevas

Publications and source records attributed to D Cuevas.

7 recordsLinked to original sources

PubMed2001

Short-term follow-up results in 795 nonpalpable probably benign lesions detected at screening mammography.

PURPOSE: To evaluate short-term follow-up of nonpalpable probably benign lesions in a 2-year mammographic screening. MATERIALS AND METHODS: Of 13,790 women aged 45-65 years who underwent first-round screening, 795 (5.8%) underwent short-term mammographic follow-up (every 6 months for 2 years) of nonpalpable probably benign lesions (eg, masses, focal asymmetric densities, and calcifications) previously assessed at an additional imaging evaluation, including ultrasonography. When no changes were found at short-term mammographic follow-up, women were assigned to the 2-year screening interval. Needle localization and surgical biopsy were performed when the lesion progressed (was enlarged or had an increased number or size of calcifications or modification of their initial characteristics). The effectiveness of this approach was evaluated with statistical analysis. RESULTS: Of 795 lesions, 788 (99%) remained stable, and seven (1%) had changes prompting surgical biopsy. Two cancers (0.3%), one microinvasive intraductal carcinoma and one 7-mm invasive ductal carcinoma without positive nodes, were found. Four of the five benign histologic results were probably benign calcifications with progression at short-term follow-up. The sensitivity, specificity, accuracy, and positive and negative predictive values were 100%, 99%, 99%, 29%, and 100%, respectively. CONCLUSION: The benign nature of most nonpalpable probably benign lesions can be typified with short-term mammographic follow-up. This approach permitted identification of a few low-stage carcinomas, but progression in the probably benign calcifications was usually unrelated to malignancy.

Aged↗

PubMed1996

Purification and partial characterization of a new anti-A1 lectin of Phaseolus coccineus collected in Oaxaca, Mexico.

It is well known that Phaseolus species contains lectins of various specificities 1-4. Runner bean5 and different varieties of Ph.coccineus described by Ochoa et al6, are not specific to human blood groups. They react indistinctly with erythrocytes of the ABO system. However the lectin of Ph. lunatus (lima bean)7 is specific to the blood group type A, a classic example of that specificity. Sometime ago, we discovered a new lectin in a variety of edible bean of Ph. coccineus in the flora of the state of Oaxaca in Mexico, cultivated exclusively in the small community of Jamiltepec, near the Pacific coast, which presented strong hemagglutinating anti-A1 activity. In this report we describe a chromatographic technique for the isolation and purification of this lectin. The molecule is a tetramer with a molecular weight of 120 kDa. It requires Ca++ or Mg++ for activity, and it is inhibited by N-Acetylgalactosamine (GalNac) at concentration of 2.8 mM., NN' N' Triacetylchitotriose, 4-O(4-O-D-Galactopyranosyl) -D-Galatopyranosyl-D-Glucopyranose, and N' Diacetylchitobiose inhibited at moderate concentration (20mM). Conalbumin and ovoalbumin, also inhibited hemagglutination.

ABO Blood-Group System↗

PubMed1991

The effect of low-dose dopamine infusion on cardiopulmonary and renal status in premature newborns with respiratory distress syndrome.

To study the effects of infusion of low doses of dopamine hydrochloride on cardiopulmonary and renal status in premature newborns with respiratory distress syndrome, 49 newborns were randomly assigned to three groups: group 1 (18 patients) received no dopamine and was the control group; group 2 (16 patients) was infused with a dose of dopamine measuring 1.0 micrograms/kg of body weight per minute for 72 hours; and group 3 (15 patients) was infused with a dose of dopamine measuring 2.5 micrograms/kg of body weight per minute for 72 hours. Birth weights, gestational ages, post-natal ages, and cardiopulmonary status of all groups at the start of the study were comparable. Continuous infusion of these low doses of dopamine for 3 days after birth did not significantly improve levels of blood gases, acid-base balance, or clinical outcome. In newborns with systemic hypotension, dopamine improved cardiovascular status and caused early return of blood pressure to the normal range. Infusion of low doses of dopamine produced mild to moderate natriuresis and insignificant increases in glomerular filtration rate and urine volume.

Acid-Base Equilibrium↗

PubMed1990

Tracheal agenesis.

Tracheal agenesis is a rare congenital anomaly. We report a case and review the cases previously reported. Clinical features that might indicate tracheal agenesis include antenatal polyhydramnios, severe respiratory distress, absence of an audible cry, failure to advance an endotracheal tube beyond the larynx, a palpable distal trachea, clinical improvement after esophageal intubation, and roentgenographic absence of a tracheal air column with an abnormal position of the carina. For immediate management of the affected infant, we recommend intubation of the esophagus with an endotracheal tube to provide an air passage, and determination of the level of the defect by careful use of contrast material and roentgenography. Infants having type I tracheal agenesis may benefit from immediate tracheostomy.

Bronchial Fistula↗

PubMed1990

Psychoneurotic and psychopathic personalities of polydrug abusers and effects of didactic instruction.

An investigation into the use of psychometric assessment instruments to produce psychographic profiles which proved superior to the use of individual measures on drug accepting versus drug rejecting age generational gaps is appropriate when considering drug and alcohol education programs. Clinical studies show that polydrug abusers have many psychoneurotic and psychopathic traits which can be measured through valid personality tests. Cuevas (1989), employed the Western Personality Inventory (Manson 1963) to identify individuals whose behavior and personality structure indicated they were polydrug users or had serious polydrug problems. The instrument revealed that a combinative process utilizing comparison groups from known polydrug abusers as a discriminant analysis technique with controls provided a high degree of accuracy. A high degree of precision in prediction was maintained in validation trials on independent samples. The personality characteristics and traits were extracted from a combination of commonly ordered personality tests. Results of the investigation indicate that clinical usage of the screening procedure is readily available without sophisticated computer support or the need for trained psychometricians. Additional results identified the process as interventive, therefore providing a simple way to produce early didactic preventive instruction.

Adult↗

PubMed1990

Subunit structure of karatasin, the proteinase isolated from Bromelia plumieri (karatas).

Close to 15% of the karatasin proteinase activity in the fruit juice of Bromelia plumieri (karatas) is present outside dialysis Visking tubing in 7 days in 0.2 M acetate buffer (pH) 3.5 or 6.5) containing phenyl mercuric acetate. The small proteinase(s), distinct from the 85% activity in juice due to nondialysable karatasin with a reported Mr of 24,868, separates across Spectrapore (13 kDa) membranes but not across Spectrapore with 3.5 kDa average pore diameter. The dialyzed proteinase is named karatasin-D (K-D). Purified non-Dialysable karatasin can be dissociated to what seems to be K-D by incubation in a buffer solution, containing SDS and 2-mercaptoethanol with phenyl mercuric acetate, in dialysis experiments for 8 days at room temperature using Spectrapore 13 kDa tubing. Thus, native karatasin in B. plumieri fruit juice seem to be the result of association of 2 small molecular mass K-D subunits, linked together by disulfide bonds and electrostatic forces, in equilibrium with small amounts of free K-D molecules. The amino acid composition and partial sequence of karatasin up to the 14th position from the amino terminus have discrete analogies with papain and with stem bromelain.

Amino Acid Sequence↗

PubMed1987

Chest physiotherapy in preterm infants with RDS in the first 24 hours of life.

To evaluate if chest physiotherapy is beneficial to premature infants with respiratory distress syndrome (RDS) during the first 24 hours of life, 20 infants were randomly assigned to two groups; 10 infants in Group I received routine chest physiotherapy and suction, and 10 infants in Group II received suction only. The birth weight, gestational age, postnatal age, Apgar scores, blood gases, acid-base status, and ventilatory requirements prior to study were comparable between the two groups. There were no significant differences between the groups in the amount of endotracheal secretions removed, the PO2/FIO2 ratio, blood gases, and pH during the study. The incidence of patent ductus arteriosus (PDA), bronchopulmonary dysplasia (BPD), Grade I and II intraventricular hemorrhage (IVH), and mortality was comparable. However, five of 10 Group I and zero of 10 Group II infants developed Grade III or IV IVH (P less than 0.05).

Blood Gas Monitoring, Transcutaneous↗