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Biomedical subjects

R Bustamante

Publications and source records attributed to R Bustamante.

At least 19 recordsLinked to original sources
PubMed2005

Cystatin C as a marker of renal function in kidney transplant patients.

INTRODUCTION: Serum creatinine (sCr) is the most commonly used biochemical parameter for gauging kidney function, but, due to its limitations, it is not the ideal marker for glomerular filtration rate (GFR). Cystatin C (sCyC) appears to be an endogenous marker of GFR. AIM: To assess the use of sCyC as a marker of renal function in kidney transplant patients, we compared it with sCr and with creatinine clearance either in a 24-hour urine or calculated using the Cockroft-Gault formula. METHODS: Among 78 patients (62.8% men, 37.2% women) undergoing kidney transplantation (average age 44.87 +/- 13.37 years) we determined at 2, 5, 7, 15, and 30 days, and 6, 12 and 18 months after kidney transplantation: sCr (using the Jaffé colorimetric method), sCyC (immunonephelometry), creatinine clearance with a 24-hour urine, creatinine clearance using the Cockroft-Gault formula. RESULTS: During the first 30 days following transplantation, there was a progressive decline in sCr levels. sCyC increased up to the fifth day, coinciding with the highest doses of steroids, and then decreased. At 6, 12, and 18 months, there was a correlation between sCyC and sCr, creatinine clearance in a 24-hour urine or calculated with the Cockroft-Gault formula (R = 0.859; R = -0.713, and R = -0.684, respectively, P < .001.) CONCLUSIONS: sCyC is an endogenous marker of GFR. Its limitations relate to its being affected by the high doses of steroids in the first days following transplantation. In the 18-month posttransplant period, it correlated with creatinine clearance in a 24-hour urine or calculated by the Cockroft-Gault formula.

Adult↗
PubMed2004

Ventilatory responses and carotid body function in adult rats perinatally exposed to hyperoxia.

Hypoxia increases the release of neurotransmitters from chemoreceptor cells of the carotid body (CB) and the activity in the carotid sinus nerve (CSN) sensory fibers, elevating ventilatory drive. According to previous reports, perinatal hyperoxia causes CSN hypotrophy and varied diminishment of CB function and the hypoxic ventilatory response. The present study aimed to characterize the presumptive hyperoxic damage. Hyperoxic rats were born and reared for 28 days in 55%-60% O2; subsequent growth (to 3.5-4.5 months) was in a normal atmosphere. Hyperoxic and control rats (born and reared in a normal atmosphere) responded with a similar increase in ventilatory frequency to hypoxia and hypercapnia. In comparison with the controls, hyperoxic CBs showed (1) half the size, but comparable percentage area positive to tyrosine hydroxylase (chemoreceptor cells) in histological sections; (2) a twofold increase in dopamine (DA) concentration, but a 50% reduction in DA synthesis rate; (3) a 75% reduction in hypoxia-evoked DA release, but normal high [K+]0-evoked release; (4) a 75% reduction in the number of hypoxia-sensitive CSN fibers (although responding units displayed a nearly normal hypoxic response); and (5) a smaller percentage of chemoreceptor cells that increased [Ca2+]1 in hypoxia, although responses were within the normal range. We conclude that perinatal hyperoxia causes atrophy of the CB-CSN complex, resulting in a smaller number of chemoreceptor cells and fibers. Additionally, hyperoxia damages O2-sensing, but not exocytotic, machinery in most surviving chemoreceptor cells. Although hyperoxic CBs contain substantially smaller numbers of chemoreceptor cells/sensory fibers responsive to hypoxia they appear sufficient to evoke normal increases in ventilatory frequency.

Age Factors↗
PubMed1997

Determination of a sedative dose and influence of droperidol and midazolam on cardiovascular function in pigs.

Twelve pigs were randomly assigned to 1 of 2 groups, droperidol or midazolam, to determine a sedative dose of each drug that would facilitate handling of the pigs. Each pig in the group received all of the test doses with 5-7 d between treatments (droperidol--0.1, 0.3, 0.6 mg/kg, or midazolam--0.25, 0.5, 1.0 mg/kg) and saline (3 mL), i.m. One investigator, unaware of the treatment administered, assessed the time of onset, degree, and duration of sedation. The 0.3 mg/kg dose of droperidol and 0.5 mg/kg dose of midazolam were judged to be the most suitable for sedation and produced similar degrees of sedation, although the onset and duration of sedation was significantly longer for the droperidol group. The effects of these 2 doses on heart rate, respiratory rate, systolic blood pressure, and rectal temperature were assessed in 12 pigs randomly assigned to 1 of the 2 treatments. Respiratory rate decreased significantly with droperidol at 10, 15, and 30 min. Temperature was significantly decreased at 60 min following midazolam. This study demonstrates that 0.3 mg/kg i.m. of droperidol and 0.5 mg/kg i.m. of midazolam induce adequate sedation in pigs with minimal cardiorespiratory changes.

Animals↗
PubMed1992

[The interruption of atrioventricular conduction by cardiac fulguration in patients with supraventricular tachycardias. The mid- and long-term results].

Catheter ablation of the atrioventricular node is a therapeutic technique for the treatment of patients with drug-refractory supraventricular tachyarrhythmias. In our Arrhythmia Unit 25 patients (8 women, 17 men) aged (mean +/- DE) 56 +/- 10 years have undergone fulguration of the atrioventricular junction since 1986. The more frequent treated rhythm disturbance was atrial flutter or fibrillation, with uncontrolled rapid ventricular response. Absence of organic heart disease was diagnosed in 9 patients; the remainder had valvular heart disease (2), cor pulmonale (2), cardiomyopathy (7), hypertensive heart disease (2) and Wolff-Parkinson-White syndrome (3). Under general anesthesia 1.8 +/- 0.8 shocks/patients were delivered along 1.2 +/- 0.7 sessions/patient. In 23 of 25 patients (92%) complete atrioventricular block was achieved, and a pacemaker was implanted. There were no complications. The other 2 patients were referred to surgery for cryoablation of the atrioventricular junction. Patients were followed for an average of 21 +/- 12 months. Four patients have died: two due to congestive heart failure, which was present prior to the ablation procedure, the third because of a metastatic carcinoma, and the fourth had a sudden death 14 months after the procedure (he had dilated cardiomyopathy and Wolff-Parkinson-White syndrome). The remainder in chronic stable complete atrioventricular block are asymptomatic for arrhythmias and without antiarrhythmic medication.

Adult↗
PubMed1986

Bacterial meningitis in Arizona American Indian children.

Bacterial meningitis is a major cause of morbidity and mortality in Arizona infants and children. A retrospective review of 102 cases of meningitis occurring in the American Indian population documents the prevalence of the Haemophilus influenzae organism with a peak incidence in the first year of life. The rate of H influenzae resistance to ampicillin was 16%. Overall morbidity and mortality rates are comparable with reviews of diverse populations, but there is an exceptional mortality and prolonged hospitalization in patients less than 1 year of age. The development of an efficacious vaccine against H influenzae may substantially reduce and prevent this cause of meningitis.

Adolescent↗
PubMed1986

Cesarean birth outside the natural childbirth culture.

The meaning of cesarean birth to women who are not typical members of the natural childbirth culture was examined. Fifty women who received obstetric care in a public inner-city hospital serving the medically indigent and who sought minimal preparation for childbirth were interviewed. The findings suggest that the women used distancing behaviors prenatally and postdelivery to cope with the idea and reality of cesarean birth. In addition, the women did not display the psychic wounding following cesarean birth reported by natural childbirth followers.

Adolescent↗
PubMed1981

Human papilloma virus type I purified from human genital warts.

Human wart virus (HPV) was isolated from a pool of genital warts. The electrophoretic mobility of virion proteins was studied by SDS polyacrylamide gel electrophoresis and showed the same pattern as that obtained with HPV-1. The analysis of DNA after restriction enzyme digestion with the endonucleases Hind III and Hae III, and nucleic acid hybridization did not show any difference with HPV-1. The viral particles were agglutinated by anti-HPV-1 serum, as shown by electron microscopic particle agglutination test. Furthermore, the immunological properties of this virus were investigated with guinea pig antiserum. Serologically, no antigenic cross-reaction between common and genital wart viruses were shown by immunodiffusion and immunofluorescence tests, whereas cross-reactions were detected between plantar and genital wart viruses. These results allow to think that HPV-1 can induce plantar warts as well as genital warts.

Animals↗
PubMed1980

Binding specificity of guinea pig anti-alpha-keratin polypeptide sera on human keratinocytes: comparison of their receptors with those of human epidermal cytoplasmic antibodies.

Experimental anti-keratin polypeptide sera (KPS) which were prepared by immunizing guinea pigs with the P1 polypeptide (molecular weight: 67 0000 dalton) of alpha-keratin of normal human stratum corneum, were shown to react in immunofluorescence only to cell cytoplasmic antigen of the upper layers of the epidermis. No staining was detected in the basal layer. An immunolabeling performed on free epidermal cells obtained after trypsinization demonstrated by electron microscopy that receptors for KPS were tonofilaments. Minor proportions of negative cells containing tonofilaments and numerous melanosomes detected might correspond to the basal cells. An IF pattern similar to that seen with KPS was observed with some human epidermal cytoplasmic sera (ECS). However, reciprocal blocking tests performed on both rabbit lip and normal human skin with the different sera showed no inhibition. No cross-reaction was detected by immunodiffusion test between whole purified alpha-keratin and human ECS. In electron microscopy, the receptors for ECS appeared not to be keratin-like, but were located on a granular part of the peripheral keratinocyte cytoplasm. These findings confirmed two steps (basal and malphighian layers) in epidermal differentiation defined by antigenic markers and especially by the alpha-keratin component of MW 67 000 d present in normal stratum corneum.

Animals↗
PubMed1977

Immunoglobulin-producing cells in the inflammatory infiltrates of cutaneous tumors. Immunocytologic identification in situ.

An immunocytochemical technique has been developed for the identification in situ of immunoglobulin-producing cells in tissues fixed in Bouin's solution and embedded in paraffin. Technical details are discussed as well as the application of the technique to the study of plasma cells in the inflammatory infiltrate around cutaneous tumors. Preliminary results have been obtained with basal cell epitheliomas, squamous cell carcinomas, and malignant melanomas. IgA-producing cells were present in all tumors. IgG-producing cells were present in variable frequency, depending on the type of tumor, and IgM-producing cells were found only in basal cell epitheliomas and squamous cell carcinomas.

Antibody-Producing Cells↗
PubMed1977

Characterization of mononuclear cells in the inflammatory infiltrates of cutaneous tumours.

The identification of mononuclear cells extracted from cutaneous tumours (basal cell carcinoma, squamous cell carcinoma and superficial, spreading melanoma) has been investigated. The relative numbers of T cells and B cells have been determined using the E-rosette test and the EAC-rosette test. The results have been compared to those of delayed hypersensitivity type reactions. Different cell distribution patterns (E/EAC ratio) have been found in the infiltrates according to the type of tumour. An immunocytochemical technique has been developed for the identification in situ of immunoglobulin-producing cells in the inflammatory infiltrates. In each case the class of immunoglobulin (IgM, IgG or IgA) has been identified and the relative frequency of Ig-producing cells has been determined. The results indicate humoral and cellular immune responses with variations attributable to the type of tumour. In weakly malignant tumours, the infiltrate is characterized by an elevated number of T lymphocytes and numerous plasma cells which secrete all classes of Ig; in highly malignant tumours it is characterized by a reduced number of both T lymphocytes (E rosette) and plasma cells which do not secrete all classes of Ig.

B-Lymphocytes↗