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Biomedical subjects

C Aguirre

Publications and source records attributed to C Aguirre.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Determination of 25-hydroxyvitamin D serum levels and its seasonal variations in healthy young people].

BACKGROUND: 25-hydroxyvitamin D has a longer half life and its serum levels have less daily variations than calcitriol. Thus, its measurement is a better indicator of vitamin D status. AIM: To measure 25-hydroxyvitamin D levels in normal subjects during summer and winter. PATIENTS AND METHODS: Vitamin D was measured using a competitive protein binding radioassay in 61 subjects (27 male) aged 21 to 57 years old, during July and August (winter) and February and March of the next year (summer). RESULTS: 25-hydroxyvitamin levels were 28.8 +/- 1.5 and 30.9 +/- 2.3 ng/ml during winter and summer respectively. No differences were found between men and women. Ninety five percent confidence levels were between 13 and 50 ng/ml. Levels in one patient with malabsorption were 9.3 ng/ml, in 2 patients with hypophosphatemic osteomalacia were 2.1 and 9.3 ng/ml, in 12 patients with alcoholic cirrhosis were 16.4 +/- 1.3 ng/ml, in 4 patients with primary osteoporosis were 23.3 +/- 0.7 and in three patients receiving vitamin D were 334 +/- 33.2 ng/ml. CONCLUSIONS: Normal levels of 25-hydroxyvitamin D range from 13 to 50 ng/ml in normal adults, there are no differences between men and women and seasonal variations are minimal.

Adult↗
PubMed1995

Influence of vitamin C on the absorption and first pass metabolism of propranolol.

The effect of ascorbic acid on the availability of propranolol has been examined. After oral administration of propranolol 80 mg with or without ascorbic acid pretreatment (2 g), the plasma concentrations and urinary excretion of propranolol and its metabolites, 4-hydroxy-propranolol and propranolol-conjugated, were determined by HPLC. Compared to controls, vitamin C decreased the maximum concentration of propranolol from 463 to 334 nmol.l-1, and the area under the propranolol concentration-time curve (from 0 to 24 hours) from 3.13 to 1.96 mumol.l-1.h. The time to reach maximum propranolol concentration was increased from 1.9 to 2.7. The total amount of drug recovered in urine has also significantly diminished (from 12.6 to 4.29 mg). No change in elimination rate was observed, indicating that ascorbic acid had affected both the absorption process and the first pass metabolism. The heart-rate decreased less when propranolol was administered with ascorbic acid in comparison to control subjects, although this interaction has little biological importance.

Administration, Oral↗
PubMed1995

Detection of Anaplasma ovis infection in goats by major surface protein 5 competitive inhibition enzyme-linked immunosorbent assay.

A competitive inhibition enzyme-linked immunosorbent assay (ELISA) based on a major surface protein 5 (MSP5) B-cell epitope conserved among Anaplasma species was used to detect goats infected with Anaplasma ovis. We examined strains of A. ovis isolated from goats in Kenya and demonstrated that MSP5 and the target B-cell epitope, bound by monoclonal antibody ANAF16C1, were conserved. Sera from 149 goats in four regions of Kenya and from 302 goats in six U.S. states were tested for the presence of epitope-specific antibodies with the MSP5 competitive inhibition ELISA. Evidence that the assay can be used to detect A. ovis-infected goats includes the following: (i) 53 goats raised in confinement with arthropod control were all seronegative; (ii) six goats experimentally infected with A. ovis seroconverted at the same time that they developed detectable rickettsemia; (iii) seroconverted goats remained seropositive, consistent with the persistence of A. ovis in goats and the presence of anti-MSP5 antibody in cattle persistently infected with Anaplasma marginale; and (iv) 119 of 127 known A. ovis-infected goats in Kenya were seropositive. A. ovis infection, as determined serologically and by demonstration of infected erythrocytes, in goats from the four regions in Kenya was highly prevalent. In contrast, despite the presence of A. ovis and competent arthropod vectors in the United States, the prevalence of infection appeared to be very low. The high prevalence in Kenya and the occurrence of anemia in persistently infected goats may be impediments to current efforts to increase milk yields on small farms.

Anaplasma↗
PubMed1995

Calcareous corneal degeneration: report of two cases.

Band keratopathy, calcium salts in Bowman's membrane, is the most classic form of corneal calcification seen in clinical practice. However, calcareous degeneration, calcium deposition involving the full corneal thickness, is rare. We reviewed the clinical and histopathological records of two patients with severe dry eyes and calcareous corneal degeneration. In each case, complete ophthalmic examination and histopathological study were performed. Both patients had severe dry eyes, case 1 secondary to graft-versus-host disease and case 2 secondary to rheumatoid arthritis, and a persistent epithelial defect and anterior segment chronic inflammation. Both patients underwent repeated penetrating keratoplasties. Histological examination of the corneal buttons showed that calcareous corneal degeneration and band keratopathy were coincident in both cases. Both patients received postoperative medications for high-risk grafting. The mechanisms of corneal calcification may be the same in calcific band keratopathy and calcareous corneal degeneration.

Adult↗
PubMed1995

[The effect of fluoxetine on insulin resistance in non diabetic obese patients].

Fluoxetine, a serotonin re-uptake inhibitor with antidepressive and appetite reduction effects, could improve insulin sensitivity. The aim of this work was to assess this effect of fluoxetine in obese subjects. We studied 12 subjects with a body mass index over 30, with a normal oral glucose tolerance test and not subjected to dietary restrictions. Insulin sensitivity using Bergman's minimal model, sex hormone binding globulin (SHBG) and insulin like growth factor binding protein 1 (BP 1) were evaluated before and after three weeks of treatment with 60 mg OD of fluoxetine. During treatment, subjects lost a mean of 1.9 kg. When compared with basal values, insulin sensitivity index (S1) improved significantly at the end of treatment (1.71 +/- 0.44 and 2.72 +/- 0.63 respectively), SHBG increased (28.9 +/- 5.1 and 18.2 +/- 3.4 nM/ml respectively) and BP 1 did not change (2.8 +/- 0.9 and 1.5 +/- 0.3 ng/ml respectively). The changes in insulin sensitivity did not correlate with weight changes (r = 0.4 NS). Weight or insulin sensitivity changes did not correlate with initial degree of insulin resistance. We conclude that the improvement in insulin sensitivity elicited by Fluoxetine is not related to weight changes and may be useful in the treatment of insulin resistant obese subjects.

Adult↗
PubMed1995

[Effect of a 17 beta estradiol gel preparation on hormone levels in menopausal women].

Different delivery forms of supplemental estrogens may differ in their hormonal effects. The aim of this study was to assess the effects of a daily dose of 2.5 g of 17 beta estradiol transdermal gel, given during four weeks, on hormone levels of six postmenopausal women. At the fourth week we observed a significant increase in estradiol and a decrease in FSH levels. Estrone levels also increased but the estradiol/estrone ratio was maintained in values over 1. No changes in SHBG or IGF1 levels were observed. Two patients that used the gel in the abdominal skin achieved lower estradiol levels (below 60 pg/ml). We conclude that the gel increased serum estradiol levels over 60 pg/ml in four of six women, that there is a big individual variability and the application zone could influence the serum estradiol levels achieved.

Administration, Cutaneous↗
PubMed1994

Decrease in penbutolol protein binding as a consequence of treatment with some alkylating agents.

The effect of in vitro treatment of serum with the alkylating agents carmustine (BCNU) and mechlorethamine on the protein binding of penbutolol, a basic agent mainly bound to alpha 1-acid glycoprotein (AAG), was investigated. The free fraction of penbutolol increased significantly (P < 0.001) after the treatment of serum with BCNU (5.27+ +/- 0.47%) and with mechlorethamine (5.23% +/- 0.17%), being 1.98% +/- 0.18% in serum not treated with BCNU or mechlorethamine. In addition, after incubation with BCNU (2 h), the free fraction of penbutolol continued increasing (10.96% +/- 0.70% vs 5.27% +/- 0.47% at time 0; P < 0.001), whereas it remained unchanged after incubation with mechlorethamine. Moreover, dialysis against saline for 24 h did not restore the free fraction of penbutolol, which increased after treatment with carmustine (9.05% +/- 1.24% vs. 11.04% +/- 1.55%, nondialyzed). We concluded that the treatment of cancer patients with alkylating agents could alter the serum proteins and modify their binding capacity, and this should be taken into account in the simultaneous treatment of these patients with other basic drugs like penbutolol, e.g., methadone.

Adult↗
PubMed1994

A study of 500 cases of acute renal failure (1978-1991).

A retrospective study of 500 consecutive cases of acute renal failure (ARF) in a period covering 1978 through 1991 is presented. A total of 316 females and 182 males with an average age of 46.4 years (14 to 84) had a global survival rate of 68%. Oligoanuric ARF was present in 77% of the patients and, except in 13 cases, all were dialyzed with varied techniques. The treatment plan consisted of early and repetitive dialysis, rational use of antibiotics, and parenteral and/or oral nutritional support. The patients have been divided into three main categories according to etiology: gyneco-obstetric, medical, and postsurgical cases, the latter having the poorest survival rate. With regard to ARF post-septic abortion, we strongly believe that a hysterectomy should not be carried out except in the presence of gangrene or proven uterine perforation, as surgery increases the morbomortality rate in these septic patients.

Abortion, Septic↗
PubMed1994

[Microwave transurethral thermotherapy in the treatment of prostatic adenoma].

We report 195 patients with prostatic adenoma treated with microwave transurethral thermotherapy. All patients were initially subjected to a clinical assessment including Madsen-Iversen symptom score, digital rectal examination, measurement of urine flow rate and residual urine volume, transrectal prostatic ultrasound examination and blood prostate specific antigen determination. A prostatron machine was used, installing an urethral probe under local anesthesia. Endourethral and rectal temperatures were simultaneously measured and the procedure was controlled by a special software. The treatment was performed in an outpatient basis with a single procedures that lasted 60 min. Of 31 patients with chronic urinary retention, 28 were left voiding spontaneously, without urethral catheters and 84% of 164 symptomatic patients were relieved. No complications occurred, although 31.1% of patients has a transitory urinary retention after the procedure. It is concluded that microwave thermotherapy is a good therapeutic alternative for prostatic adenoma.

Aged↗
PubMed1994

[Improvement of insulin sensitivity associated with the prolonged use of Acipimox in ++a morbid obese patient].

Insulin sensitivity was estimated in a morbidity obese, insulin-resistant, glucose-intolerant patient before and after 4 weeks of treatment with Acipimox (250 mg t.i.d), an orally-administered, long-acting antilypolitic drug. The ensuing fall in circulating levels of fasting free fatty acids was associated with a clear amelioration of insulin resistance, as assessed by a minimal model analysis of a frequently sampled intravenous glucose tolerance test as well as by an oral glucose tolerance test. Similarly, this treatment brought about a reappearance of GH response to oral stimulation with clonidine. The evidence showing Acipimox-induced amelioration of insulin resistance in this patient without diet, exercise or weight loss should encourage exploring the potential utility of this drug in this type of patients.

Adult↗
PubMed1994

[The clinical estimate of adiposity is not a good predictor of insulin tissue sensitivity measured with a minimal model analysis].

Fifteen male volunteers, aged 30 to 40 years old, were classified according to body mass index (BMI) as lean (n = 5, BMI less than 20 kg/m2), normal (n = 5, BMI 20-25) or obese (n = 5, BMI over 30). Glucose intolerance was ruled out by a normal oral glucose tolerance test and insulin sensitivity (SI) and glucose effectiveness (SG) were estimated by a minimal model analysis of a frequently sampled intravenous glucose tolerance test modified by an intravenous insulin injection at minute 20. The MINMOD program was fed with 29 or 12 values (reduced sampling schedule). Despite a significant inverse correlation between BMI and SI (r = -0.533 p < 0.05), the latter parameter overlapped among groups and the correlation was lost when obese individuals were not considered. Waist/hip ratio correlated modestly with SI (r = -0.52 p < 0.05). SG did not correlate with BMI. Using the reduced sampling schedule. SI values had a correlation coefficient of 0.78 with those calculated using the usual sampling schedule, although they were 82% lower. We conclude that only a BMI of over 30 accurately predicts a low SI, and that waist/hip ratio does not have a better predictive power.

Adult↗
PubMed1994

[Laparoscopic lumboaortic retroperitoneal lymphadenectomy in testicular neoplasm].

Lumboaortic lymphadenectomy is a therapeutic alternative for patients with nonseminomatous testis tumors and its principal untoward effect is the loss of ejaculation. The anatomic knowledge of lymph node metastasis allows lower limit definition of aortic dissection, maintaining the diagnostic sensitivity and ejaculation. We report three patients with nonseminomatous testis tumors subjected to a reduced video-laparoscopic lumboaortic lymphadenectomy. An adequate amount of tissue was obtained in all and lymph node metastasis found in two. No complications occurred and patients were discharged 48 hours later. It is concluded that this technique is an alternative staging technique with low morbidity that allows a rapid patient discharge.

Adult↗