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Biomedical subjects

A Peralta

Publications and source records attributed to A Peralta.

At least 19 recordsLinked to original sources
PubMed2002

Elastic interaction of surface steps: effect of atomic-scale roughness.

Elastic interactions of atomic steps can greatly impact surface morphology. Recent atomistic calculations and experimental observations find the standard dipole model of steps is valid only for very large step separations. In this Letter, a new model is presented that displays remarkable agreement with atomistic predictions for step separations larger than just a few step heights. It is shown that the interaction energy of steps exhibits a novel intermediate-ranged behavior and that, for particular systems, step interactions switch from repulsive to attractive as separation distance decreases.

Journal Article↗
PubMed2001

Symptom management in hospice and palliative care.

Managing the symptoms of advanced disease at the end of life is one of the most challenging aspects of medicine for most clinicians. Traditional textbooks provide limited resources for treating patients at this stoichiometric point in their disease. This article provides an overview in the treatment of common symptoms at the end of life, such as anxiety, anorexia and cachexia, constipation, delirium, dyspnea, fatigue and asthenia, nausea and vomiting, malignant intestinal obstruction, and terminal restlessness. By addressing these symptoms, the physician can play a key role in the patient's achievement of a peaceful, symptom-free, and dignified death in the setting of their choice.

Anorexia↗
PubMed1999

Induction of a protective antibody response to foot and mouth disease virus in mice following oral or parenteral immunization with alfalfa transgenic plants expressing the viral structural protein VP1.

The utilization of transgenic plants expressing recombinant antigens to be used in the formulation of experimental immunogens has been recently communicated. We report here the development of transgenic plants of alfalfa expressing the structural protein VP1 of foot and mouth disease virus (FMDV). The presence of the transgenes in the plants was confirmed by PCR and their specific transcription was demonstrated by RT-PCR. Mice parenterally immunized using leaf extracts or receiving in their diet freshly harvested leaves from the transgenic plants developed a virus-specific immune response. Animals immunized by either method elicited a specific antibody response to a synthetic peptide representing amino acid residues 135-160 of VP1, to the structural protein VP1, and to intact FMDV particles. Additionally, the immunized mice were protected against experimental challenge with the virus. We believe this is the first report demonstrating the induction of a protective systemic antibody response in animals fed transgenic plants expressing a viral antigen. These results support the feasibility of producing edible vaccines in transgenic forage plants, such as alfalfa, commonly used in the diet of domestic animals even for those antigens for which a systemic immune response is required.

Administration, Oral↗
PubMed1997

Medical physics is alive and well and growing in South East Asia.

In recent years there has been a significant economic growth in South East Asia, along with it a concurrent development of medical physics. The status of four countries--Malaysia, Thailand, the Philippines and Indonesia are presented. Medical physicists in these countries have been experiencing the usual problems of lack of recognition, low salaries, and insufficient facilities for education and training opportunities. However the situation has improved recently through the initiative of local enthusiastic medical physicists who have started MS graduate programs in medical physics and begun organizing professional activities to raise the profile of medical physics. The tremendous support and catalytic roles of the American Association of Physicists in Medicine (AAPM) and international organizations such as International Organization for Medical Physics (IOMP), International Atomic Energy Agency (IAEA), World Health Organization (WHO), and International Center for Theoretical Physics (ICTP) have been instrumental in achieving progress. Contributions by these organizations include co-sponsorship of workshops and conferences, travel grants, medical physics libraries programs, and providing experts and educators. The demand for medical physicists is expected to rise in tandem with the increased emphasis on innovative technology for health care, stringent governmental regulation, and acceptance by the medical community of the important role of medical physicists.

Asia, Southeastern↗
PubMed1995

Evolution of patients with clinical neurocardiogenic (vasovagal) syncope not subjected to specific treatment.

The purpose of this prospective study was to analyze the natural history of patients with clinical neurocardiogenic syncope. The results obtained with some therapeutic strategies in the prevention of neurocardiogenic syncope are encouraging. However, the benefit they represent when compared with the natural history of syncope has not been clearly established. Fifty-six consecutive patients with either (1) one or more episodes of syncope and a positive head-up tilt test or (2) typical history of vasovagal syncope despite a negative tilt test were monitored during a mean period of 16.1 +/- 10.2 months. Patients were discharged without any specific medication. There were no deaths during the follow-up period. Recurrences were found in 5 (8.9%) patients. The risk of recurrence was 7% after 1 year and 15% after 21 months. The prognosis of patients with clinical neurocardiogenic syncope is excellent as far as survival is concerned. Recurrences of episodes without specific treatment were uncommon after diagnosis had taken place. This finding strengthens the need to evaluate the effect of drugs with placebo control groups and to select the highest-risk group for treatment.

Adolescent↗
PubMed1995

[Use-dependence of propafenone. Clinical demonstration of the hypothesis of modulated receptors].

UNLABELLED: The aim of this study was to assess use-dependence in patients with ventricular premature contractions (VPC's) treated with propafenone, by means of the increase in heart rate using transesophageal atrial pacing. It was also analyzed whether this phenomenon was related to the antiarrhythmic effect. Fifteen patients with more than 30 symptomatic VPC's/sour were evaluated. Esophageal pacing was performed with cycles of 600 and 400 msec during periods of 1 min and with simultaneous recording of 2 or 3 EKG leads with a paper speed of 100 mm/sec. Holter monitoring (HM) was carried out in all patients. Propafenone was administered in doses of 450 and 900 mg/day, during 5-7 days, at which moment another HM and esophageal stimulation were repeated. The QRS duration (pre-treatment) was 82.6 +/- 13.5 msec (basal) and 82.4 +/- 13 msec during pacing with 600 msec cycle length (p: NS). The QRS duration with P (900 mg/day) was 96.6 +/- 20 msec (basal) (p:NS vs. pre-treatment) but during atrial pacing with 600 msec cycle length it increased to 109.3 +/- 23 msec (p < 0.0004). This use-dependence was also observed with pacing at 600 msec in patients receiving doses of 450 mg/day: 95.3 +/- 13 msec (p < 0.0001 vs. baseline QRS) (Table 1). IN CONCLUSION: 1) there was no significant increase in the QRS duration with P without pacing; 2) propafenone showed use-dependence during atrial stimulation, even with cycle length of 600 msec and with the lower doses.

Administration, Oral↗
PubMed1985

[Growth retardation, GH deficiency, hyperprolactinemia and delayed puberty].

A case of a male eleven years and three months old, brought to medical attention for short height, is reported. A deficiency of growth hormone associated with hyperprolactinemia without previous clinical manifestations is appreciated in endocrinological study. Detectable tumor is not apparent in any of the investigations performed. HGH and bromocriptine therapy is initiated, resulting in and increase in height and a decrease of prolactin. Currently, at fifteen years four months of age, clinical and analytical data suggest a case of hypogonadism and puberal retardation as well.

Child↗
PubMed1985

[Trisomy 5p: a report of 2 cases].

Authors report two patients from different families who present similar abnormalities caused by an "almost complete" trisomy of the short arm of chromosome 5 [case No. 1: 46, XY, der (20), t (5; 20) (p11;p13), mat; case No.2: 46, XY, dup (5p)]. Several family members of case No. 1 were balanced translocation carriers. Case No. 2 is probably due to de novo duplication. Clinical findings in our cases and those cited in the literature allow identification of certain main features characteristic of "almost complete" trisomy 5p: hypotonia, weak cry, mongoloid slant of eyes, epicanthus, depressed nasal bridge, auricular anomalies, bilateral cryptorchidism and, less frequently, macrocephaly, micrognathia and club feet.

Abnormalities, Multiple↗
PubMed1984

[Precocious pseudopuberty secondary to granulosa cell tumor].

A case report of pseudoprecocity secondary to a unilateral ovarian tumor of granulosa cells is presented in a 13 month old female. Clinical manifestations appeared at two months of age as unilateral enlargement of the breast, development of pubic hair and vaginal discharge. Plasma estrogen levels were elevated, whereas there was no response of FSH and LH to LH-RH stimulation. The absence of a palpable abdominal mass and a normal ultrasound examination of the abdomen must be pointed out in our case. The suspected clinical and laboratory diagnosis was later confirmed by surgical abdominal examination and ovarian histopathology study. With the exception of a minimal breast enlargement which persists at two years of age, all other signs of pseudoprecocity have disappeared after the surgical removal of the neoplasm. The importance of surgical abdominal examination must be pointed out as a diagnostic method when clinical and laboratory findings suggest an ovarian tumor inspite of normal abdominal palpation, ultrasound and roentgenology.

Female↗
PubMed1983

[Early detection of congenital hypothyroidism. Study of 31,609 determinations].

As a result of congenital hypothyroidism (CH) early detection program carried out in our clinic during the period 1978-1981, 31.609 capillary blood samples (35,7% from newborn infants) were taken on filter paper cards. An evaluation of TSH following the specific radioimmunoanalysis technique was made in all the samples, and an evaluation of T4 whenever TSH values were higher than 25 microU/ml serum. Thirteen cases of CH were detected: nine with permanent H and four with transient H. Two cases of hyperthyrotropinemia were also detected. Frequency of permanent CH in our population is of 1/3.512. Corresponding biochemical data and detailed clinical characteristics detected, including the cost of the procedure are shown. Authors emphasize on possibility of preventing brain damage and subsequent subnormality through early detection and treatment of congenital hypothyroidism, together with a suitable cost-benefit ratio, makes necessary to carry out a nationwide campaign in accordance with those centers already established.

Congenital Hypothyroidism↗
PubMed1983

[A new concept for the training of odontological human resources].

This article describes different aspects, and particularly those of the academic-administrative structure of the Dentistry Program in the Health Sciences Faculty of Universidad Católica "Madre y Maestra," in the Dominican Republic. It presents a general account of the University's approach to the problems of health, and of the events leading up to the establishing of the Program, the basis on which this was done, the theoretical framework in which the curriculum is embedded, and the methodological principles applied. It also gives a detailed description of the curriculum, including the general and specific objectives, the structure and organization, and the modules comprised in each academic year. Finally, the teaching-learning, service, and research activities, and an account of the resources available for the conduct of the Program are reviewed in brief.

Curriculum↗
PubMed1982

[Thrombocytopenia-absent radius syndrome (author's transl)].

A patient affected with thrombocytopenia and bilateral absence of radius is described. Authors present data suggesting an acquired etiology: intrauterine cytomegalovirus infection and X-ray exposure during the ovulatory period. Patient showed some radiological features not previously described: methacarpian synostosis and absence of sternum ossification centers. Anemia was etiologically related to the iron deficiency secondary to bleeding. Chronic diarrhea, a feature common in this syndrome, was caused by cow's milk protein intolerance, other causes of chronic diarrhea, like pancreatic malfunction or disaccharidal intolerance were discarted. Finally comments on the differential diagnosis of the illness, its' evolution and treatment, pointing out the possibility of an intrauterine diagnosis, crucial for a correct genetic counselling are made.

Abnormalities, Multiple↗