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Biomedical subjects

P Sierra

Publications and source records attributed to P Sierra.

25 records · Page 2Linked to original sources

T cell subsets in allergic respiratory disease using monoclonal antibodies.

Fifty patients with perennial allergic rhinitis and extrinsic allergic asthma were studied to determine the relative percentages of OKT3+, OKT4+ and OKT8+ cells as well as the OKT4+/OKT8+ ratios. The percentages of the OKT3+ cells (66 +/- 7) were reduced when compared with those of 50 healthy controls (72 +/- 6), (p less than 0.001). The mean values and deviations of the OKT4 marker produced no statistically significant differences between the patient group (44 +/- 6) and the control group (44 +/- 6). A reduction in the OKT8+ marker in the patient group was registered (20 +/- 6), (p less than 0.001). The OKT4+/OKT8+ ratio was, as a result, raised in the patient group (2.3 +/- 0.6) in relation to the control group (1.6 +/- 0.3). The reduction in the OKT3+ cells together with the imbalance in the subset inducer-helper/cytotoxic-suppressor in allergic respiratory disease could lead to non-regulation of B cells and to hyperproduction of IgE.

Adolescent↗

Effect of guancydine on systemic and renal hemodynamics in arterial hypertension.

The effect of guancydine (1-cyano-3-tert-amylguanidine) on systemic and renal hemodynamics was studied in nine patients with arterial hypertension. Antihypertensive drugs were withheld for 15 days before beginning the investigation. Average sodium intake was 105 meq/24 hours in some patients and 25 meq/24 hours in others. Patients received placebo during a control period that averaged 14 days. Guancydine was given for 7 to 18 days at an average dose of 21 mg/kg of body weight. Although mean arterial blood pressure decreased significantly in all patients, it reached normal levels in only two. There was no change in cardiac output. Glomerular filtration rate and renal plasma flow remained unchanged, whereas urinary sodium excretion diminished, suggesting an activation of the renin-angiotensin-aldosterone system. A substantial gain in body weight was noted. Nausea, vomiting, constipation, somnolence, restlessness, mental confusion, asthenia, and urine retention were observed. The anti-angiotensin effect of guancydine that has been described in animals was not observed.

Blood Pressure↗

[Early onset Münchausen's syndrome].

This study presents a clinical case description of a factitious disorder in a woman whose diagnosis was made during her childhood. The onset of the disorder took place at 12 years of age and the fundamental clinical characteristics are: limited frequency with which the diagnosis is made in this period of life as well as the multiple symptoms manifested by the patient, both abdominal as well as neurological and hemorrhaging ones. A careful analysis of the personality traits and biographic history of the patient was also performed. The characteristics of the factitious disorder in childhood, as well as the relationship of this syndrome with the personality disorders, are discussed.

Adolescent↗

[Usefulness of preoperative chest radiography in elective surgery].

OBJECTIVES: To study the prevalence of abnormalities in preoperative chest X-rays taken of patients undergoing elective surgery; to determine radiological abnormalities not expected based on the patient's case history and their influence on treatment; and to identify patients with high risk of presenting abnormal radiographs. PATIENTS AND METHODS: This retrospective study included 2,146 consecutive patients entering the hospital over a period of one year for non-cardiopulmonary surgery requiring anesthesia. Two physicians reviewed the radiodiagnostic reports on routine preoperative chest X-rays requested by surgeons. The reviewers classified the results as normal, expected abnormal and unexpected abnormal based on concordance or not between the patient's case history and the radiologist's report. RESULTS: Of the original 2,146 patients, 160 (7.4%) were excluded from the study because of incomplete case histories and/or physical exams. X-rays were taken of 1,880 (94.6%) of the 1,986 patients remaining in the study. Abnormalities were found in 508 (27%), most often in men, patients over 45, those classified as ASA III-V and those with a history of cardiovascular or lung disease, or smokers of more than 20 cigarettes/day. In 254 (13.5%), the abnormalities were not expected based on the patient's history; the physician's attitude changed toward 11 of these (4.3%), 5 of whom had cancer. Unexpected abnormalities were detected in 2 patients (0.8%) during physical examination and the real index of unexpected attitude changes based on case history and physical examination was 9 (3.5%). A new treatment based on unexpected radiological abnormalities was chosen for only 2 (0.8%) patients. The prevalence of unexpected radiological abnormalities was higher in men, in those over 45 years old and in those classified as ASA III-V. CONCLUSIONS: The prevalence of unexpected abnormalities in routine preoperative chest X-rays taken before non-cardiothoracic elective surgery is high, but the influence of their detection on patient management is minimal. The results of our study suggest that X-rays should be recommended for patients over 45; those with a history of cardiovascular or lung disease, or of cancer; smokers of more than 20 cigarettes/day; those classified as ASA III-V; and those with incomplete case histories or physical examinations.

Adolescent↗