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Biomedical subjects

F J Rodríguez

Publications and source records attributed to F J Rodríguez.

31 records · Page 2Linked to original sources
PubMed1992

Separation and determination of aminohalogenbenzophenones by high-performance liquid chromatography with electrochemical detection.

A high-performance liquid chromatographic method with electrochemical detection has been developed for the determination of three aminohalogenbenzophenones: 2-amino-2',5-dichlorobenzophenone, 2-amino-5-chlorobenzophenone and 2-amino-5-bromo-2'-fluorobenzophenone, metabolites of benzodiazepinooxazoles and other psychotropic drugs. A mobile phase of methanol-water (65:35), containing 5 mM KH2PO4 appeared to be the optimal when a 4-microns, 60-A Nova-Pak C18 column and a flow-rate of 0.75 ml/min (130 bar) were used. The temperature was optimized at 30 degrees C. The amperometric detector, equipped with glassy carbon electrode, was operated at 1.3 V versus Ag/AgCl in the DC mode. The method was applied to the determination of these compounds at two concentration levels: ppm and ppb (ng/cm3) using 2-amino-5-chlorobenzophenone as internal standard. The limit of determination was 750 pg/ml of biological fluid for each compound, and recoveries greater than 97% were obtained for spiked samples of urine and serum, using C18 Sep-Pak cartridges in the sample clean-up procedure.

Anti-Anxiety Agents↗
PubMed1986

Simple radioimmunological method for urinary 6-keto-PGF1 alpha measurement.

A radioimmunoassay for the determination of 6-keto-PGF1 alpha (stable metabolite of Prostacyclin) in urine using a specific antiserum, is described. The antibody used, showed no significant cross-reactivity with other PGS. (3H)-6-keto-PGF1 alpha has been used as tracer and a 30% Hydroxyapatite suspension was utilized for the separation of bound and free fractions. Standard curve ranges between 2 and 1000 pg thus allowing measurements in urine. Aliquots of 0.2 to 1 ml of 24 hours urinary samples were submitted to a preextraction step with Hexane in order to eliminate neutral fats. After acidifying with 0.1 N HCl to pH = 3.5-4, an Ethyl Ether extraction step was performed showing a recovery of 66%. Repeated analysis of a rat urine pool, showed 7.7 intraassay and 9.8 interassay variation coefficients. Values obtained amounted to 38.3 +/- 4.6 ng/24 h in normal rats and 133 +/- 32 ng/24 h in 5% NaCl loaded rats (p less than 0.001). The values obtained in healthy men were 508 +/- 94 ng/24 h and in women 375 +/- 136 (p less than 0.05).

6-Ketoprostaglandin F1 alpha↗
PubMed1982

[Glycosidases of mammals: association of activities and changes of levels in some disorders].

beta-Galactosidase and associated activities (beta-glucosidase and beta-fucosidase) have been studied in rabbit and bovine liver and rabbit spleen. The physico-chemical (optimal pH, pI, MW) and kinetical (Km, Vmax, Ki) properties were determined for all the activities. Two enzyme forms were separated in rabbit spleen. beta-Galactosidase, beta-fucosidase and beta-glucosidase activities were catalyzed by the same enzyme in rabbit and bovine liver. The enzyme from bovine liver showed nonlinear double-reciprocal plots, suggesting a substrate-activation model, and the presence of more than one binding site in the enzyme. The enzyme activities of several glycosidases were determined in human sera fom control groups and from patients with diabetes mellitus, pancreatitis, hepatitis, cirrhosis, stomach and breast cancer, myocardial infarction and renal failure. The results show significantly different enzyme levels for several glycosidases in all the studied diseases. Experimentally-induced diabetes mellitus, alcoholism and nephrotoxicity in rats showed different glycosidase levels in several tissues, as compared with control groups.

Alcoholism↗
PubMed1977

Response of plasma aldosterone to orthostatism during follicular and luteal phases of the normal menstrual cycle.

The responses of plasma aldosterone (A) and plasma renin activity (PRA) to orthostatism have been evaluated in 47 women during the follicular and/or luteal phase of the menstrual cycle. Three postmenopausal women and 51 men were also studied for control. Fourteen cycling women and 11 men were studied on a low sodium diet (20 mEq/day) while the rest of the subjects were on normal sodium intake. In addition, 18 women (including those postmenopausal) and 17 men were studied after intravenous administration of 20 mg frusemide. The response of A to orthostatism in women during luteal phase on normal sodium diet with or without frusemide was much greater than in men or women during follicular phase (p less than 0.01) or menopuase (p less than 0.05). However, no differences between groups could be observed in A response while on a low sodium diet. PRA response was similar during follicular of luteal phase fo the cycle as well as in men either on low or normal sodium intake with or without frusemide.

Adult↗
PubMedDate not supplied

[Identification of doctors with high pharmaceutical expenditure].

OBJECTIVE: [corrected] To identify doctors with high pharmaceutical expenditure through multiple regression of variables not exclusively dependent on the doctor's decision. To compare the agreement with the method of the Spanish national health servicem which only considered the percentage of pensioners of the doctor's list. METHODS: Cross-sectional, retrospective, descriptive study of the pharmaceutical expenditure of 220 general practitioners in the health district of Toledo (Spain) in 1999. The following variables were collected: pharmaceutical expenditure for policy-holder/month (PEP-H); age; sex; habitat; size of the list; percentage of pensioners; frequency of attendance (consults/policy-holder-year) and workload (consultations per day). A multiple regression model with backwards elimination was constructed, taking like PEP-H as the dependent variable and the remaining as the independent variables. The resultant equation enabled calculation of the expected PEP-H for each doctor and the deviation of their real expenditure ofrom the expected. Doctors were considered to have high pharmaceutical expenditure when the deviation was more than the mean plus 1 standard deviation of this distribution. RESULTS: The mean PEP-H was 2,584.4 pesetas. Differences were found (F = 11.665; p < 0.005) in PEP-H per habitat (2,723.2 in rural, 2,521.4 in semi urban and 2,168.2 in urban). A significant correlation was found (p < 0.005) between PEP-H and percentage of pensioners (r = 0.728) and frequency of attendance (r = 0.607). Our final model included percentage of pensioners, frequency of attendance, and age (F = 102.33; p < 0.005; r = 0.767; r² = 0.588; β = 206.05; β₁ = 48.27; β₂ = 61.26; β₃ = 9.55). This model were identified 25 DHPC. With the INSALUD model the identification were of 31. The Kappa index showed that agreement between both methods was 0.706 (SE 0.056) and simple disagreement was found in the classification of 24 doctors (10.9%). CONCLUSIONS: Frequency of attendance and the percentage of pensioners on doctors' lists are iclosely related to PEP-H. The indicator currently used by the Spanish national health system to identify doctors with high pharmaceutical expenditure could be improved if other variables, such as frenquency of attendance and the doctors' age, were taken into account. The adoption of this method would make budget allocation more impartial and fair.

Cross-Sectional Studies↗
PubMedDate not supplied

Spontaneous separation in idiopathic vitreomacular traction syndrome associated with contralateral full-thickness macular hole.

PURPOSE: Vitreomacular traction syndrome (VMTS) and full-thickness macular hole are two different well-known entities that on follow-up may be subjected to clinical modifications. Precisely, a spontaneous separation of idiopathic VMTS occurred in three eyes of three patients relieving in addition traction of the posterior hyaloid that had led also to a focal macular retinal pigment epithelial detachment (RPE). An association to a full-thickness macular hole was observed in the contralateral eye of one of the patients. METHODS: This is a retrospective study of three patients evaluated with fluorescein angiography and documented with optical coherence tomography using the Stratus (OCT) model 3000, with scans analysis and protocols analysis, measuring the size and shape of vitreomacular adhesions, macular thickness changes before and after the spontaneous separation of the tractional posterior hyaloid adhesion. In addition, the vitreous was evaluated with contact lens slit lamp biomicroscopy and ultrasound. The associated contralateral macular hole in one of the patients was surgically treated. RESULTS: Two of the three eyes with spontaneous separation of the VMTS recovered 20/25 central visual acuity; the other eye maintained the initial 20/50 visual acuity. The treated macular hole recovered 20/100 corrected visual acuity. CONCLUSIONS: Spontaneous separation of posterior hyaloid is a possible outcome during follow-up of idiopathic VMTS that can be well evaluated and documented with OCT while macular fluorescein angiography may be silent in cases like these presently reported. Central vision recovery can be excellent following the spontaneous separation, which releases anterior-posterior traction including on the retinal pigment epithelium and decreases macular thickness as measured with OCT. Therefore, regarding management, the indication for vitrectomy should be delayed awaiting the spontaneous release of vitreomacular traction in 4 to 6 months. The association between idiopathic VMTS in one eye and full-thickness macular hole in the opposite eye of one patient is an important pathophysiologic consideration.

Aged↗
PubMedDate not supplied

Emphysema as a result of involuntary exposure to tobacco smoke: morphometrical study of the rat.

Several attempts have been made to describe the relation that exists between tobacco smoke and emphysema, through different experimental models of the active smoker. Despite the negative effects that involuntarily inhaled tobacco smoke can have on the lung, no experimental model of the passive smoker has been proposed. In this study, an experimental model of the involuntary smoker is described and the following hypothesis proposed: Passive exposure to tobacco smoke produces morphological alterations in the rat lung, which are compatible with emphysema. Emphysema will be considered to have been caused when enlargement of the distal airspaces of the lung and lung tissue destruction are demonstrated. Sixty Wistar rats were used, divided into two groups: a control group and a group that was passively exposed to tobacco smoke for a period of 3 months. A morphometrical study of the lung was performed using a computerized system. To demonstrate enlargement of the distal airspaces of the lung, the following variables were quantified: alveolar chord and mean linear intercept index (Lm); tissue loss was demonstrated by means of the quantification of the variables: tissue density, internal alveolar perimeter (IAP), and wall thickness (WT). The elastic fiber was also quantified. The animals that were exposed to tobacco smoke displayed the following significant alterations (p < .05): an increase of the alveolar chord and of the Lm, a decrease of the IAP, WT, and tissue density, and a loss of the elastic component of the lung. On the basis of these findings, it is concluded that the rats that were exposed in a passive way to tobacco smoke display morphological pulmonary alterations that are compatible with the definition of emphysema.

Animals↗
PubMedDate not supplied

[Historical course of surgical techniques in pancreas transplantation].

Since the original description of the pancreas transplant technique in animals, initially as a pedicle transplant in 1892, free graft in 1913, and then as a vascularized organ in 1927, there have been several changes in the handling of the exocrine secretions, as well as the vascular anastomoses, and the posttransplant function in relation to the immunosuppressive therapy. The surgical technical changes have included the ligature of the duct, the free drainage to the abdominal cavity, the pancreas transplant with a duodenal segment, the chemical occlusion of the duct, and its drainage to the intestine or to the bladder with a duodenal segment. This last technique remains as the standard technique currently used for pancreas transplantation, along with the combined transplant of the kidney. This work reviews the historical aspects, the evolution of the experimental and clinical surgical techniques, and the current results associated with the surgical management of pancreas transplantation.

Adult↗