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Biomedical subjects

M Guerrero

Publications and source records attributed to M Guerrero.

84 records · Page 5Linked to original sources
PubMedDate not supplied

Serum dihydrotestosterone and testosterone concentrations in human immunodeficiency virus-infected men with and without weight loss.

Weight loss is an important determinant of disease outcome in human immunodeficiency virus (HIV)-infected men. Others have suggested that a defect in dihydrotestosterone (DHT) generation contributes to weight loss in HIV-infected men. To determine whether DHT levels correlate with weight loss independently of changes in testosterone levels, we prospectively measured serum total- and free-testosterone and DHT levels in 148 consecutive HIV-infected men and 42 healthy men. Thirty-one percent of HIV-infected men had serum testosterone levels less than 275 ng/dL, the lower limit of the normal male range; of these, 81% had normal or low LH and FSH levels (hypogonadotropic), and 19% had elevated LH and FSH levels (hypergonadotropic). Overall, serum testosterone, free-testosterone, and DHT levels were lower in HIV-infected men than in healthy men, but serum DHT-to-testosterone ratios were not significantly different between the two groups. Serum total- and free-testosterone levels were lower in HIV-infected men who had lost 5 lb or more of weight in the preceding 12 months than in those who had not lost any weight. Serum DHT levels and DHT-to-testosterone ratios did not differ between those who had lost weight and those who had not. Serum testosterone and free-testosterone levels, but not DHT levels, correlated with weight change and with Karnofsky performance status. We also performed a retrospective analysis of data from a previous study in which HIV-infected men with serum testosterone levels less than 400 ng/dL had been treated with placebo or testosterone patches designed to nominally release 5 mg testosterone over 24 hours. Serum testosterone-to-DHT ratios did not change after testosterone treatment. Changes in fat-free mass were correlated with changes in both serum testosterone (r = 0.42, P = 0.018) and DHT (r = 0.35, P = 0.049) levels. Serum total- testosterone and DHT levels were highly correlated with one another, and when the change in serum testosterone was taken into account, serum DHT levels no longer showed a significant correlation with change in fat-free mass. We conclude that DHT levels are lower in HIV-infected men than in healthy men but that neither DHT levels nor DHT-to-testosterone ratios correlate with weight loss. During testosterone treatment, serum DHT levels increase proportionately, but the increments in serum testosterone correlate with the change in fat-free mass. Our data do not support the hypothesis that a defect in DHT generation contributes to weight loss in HIV-infected men independently of changes in testosterone levels; it is possible that such a defect might exist in HIV-infected men with more severe weight loss.

Adolescent↗
PubMedDate not supplied

[High-frequency audiometry: variations in auditory thresholds in the premenstrual period].

The hormonal changes that occur during the premenstrual period have been implicated as a causative factor for many psychological and physical symptoms. The present work was undertaken to determine the effect of these hormonal changes on audition. We studied 60 ears from 30 women (20-30 years old) with regular menstrual cycles and no middle/inner ear pathology. We performed audiometries one week before menstruation and one week after it, testing the range of frequencies from 250 to 16,000 Hz. After calculating the mean pre and postmenstrual threshold the results were compared using the paired < >-Student test. We found statistical significant differences in the frequencies 9,000, 10,000 and 11,200 Hz.

Adult↗
PubMedDate not supplied

Eosinophilic gastroenteritis. Three cases involving each of the anatomo-clinical variants.

Three patients suffering from eosinophilic gastroenteritis belonging to each of the three anatomo-clinical forms are involved in this study. The disease has a high blood eosinophilia and in the anatomo-pathological studies it is established that there is an eosinophilic infiltration in some portion of the gastrointestinal tract. The localization of this infiltration in the mucous, muscular or serous layers of the digestive canal allows the three varieties to be distinguished, each one having an individual clinical pattern. In the patient with the mucous form, analytical and clinical evidence of atopy is observed, as well as certain types of food which trigger off the symptoms. The exclusion diet and the membrane-stabilizing drugs, disodium cromoglycate and ketotifen produce clear therapeutic effects. Conversely, in those patients where the eosinophilic infiltration is in the muscular or serous layers, no food inductors are found and a therapy based on diet with subsequent administration of the above-mentioned drugs proves to be ineffective. The course of the disease in these cases is unpredictable and steroid drugs must be used frequently. The clinical, anatomo-pathological and analytical characteristics, together with the therapeutic results and subsequent development, lead us to assume a reaginic immunological mechanism in the mucous membrane, but, in the other forms there is no clear pathogenic mechanism to explain the anatomo-pathological findings and the clinical symptoms.

Adult↗
PubMedDate not supplied

[Histochemical aspects of liver lesions induced in hamsters by inoculation of E. histolytica in axenic culture. II. Evidence of perinecrotic fibrosis].

The percutaneous, intrahepatic inoculation of E. histolytica trophozoites in weanling hamsters produced lesions of various shapes and sizes. The time-span between inoculation and sacrifice did not correlate with the size of the lesions. Histoenzymologic technics for acid and alkaline phosphatases, adenosinetriphosphatase (ATPase) and glucose-6-phosphate dehydrogenase (G-6-P DH) showed that the necrotic material is positive to the two former phosphatases whereas ATP-ase shows distorted bile canaliculi due to profound parenchymal alterations and the presence of G-06-P DH activity in parenchyma as well as its lack of activity in necrotic material suggests that the pentose cycle is involved in the genesis of the lesion. The presence of collagen fibers surrounding the lesions suggests that during the expansion of the lesions, there is a granulomatous inflammatory stage with fibrosis immediately followed by fibrinolysis. Four zones can be distinguished in an expanding lesion: necrosis, a zone of junction between necrosis and parenchyma which depicts a crown of invasive trophozoites surrounding the necrosis, a histiocytic halo and a zone of peripheral necrosis.

Adenosine Triphosphatases↗
PubMedDate not supplied

[Effect of propofol on oxygenation and the pulmonary short-circuit during single-lung ventilation].

OBJECTIVES: To determine the effect of propofol on pulmonary short circuit or shunt (Qs/Qt). PATIENTS AND METHODS: Nine patients undergoing scheduled thoracic surgery with single lung ventilation were studied. All patients were anesthesized with 2 mg/kg propofol followed by a continuous infusion of 4-6 mg/kg/h; fentanyl 0.3 mg followed by bolus as needed; and relaxed with atracurium 0.5 mg/kg followed by bolus of 0.1-0.2 mg/kg as needed. The ratio Qs/Qt was calculated with an FiO2 of 1 and patients in lateral decubitus. RESULTS: During double-lung ventilation Qs/Qt was 17.4 +/- 5.4% and PO2 was 430 +/- 16 mmHg, while shunt increased to 27.8 +/- 8.4% and PO2 decreased to 258 +/- 127 mmHg during single-lung ventilation. Change was significant in both cases. CONCLUSIONS: Continuous infusion of propofol produces a significant increase of Qs/Qt and a significant decrease of PaO2 during single-lung ventilation for thoracic surgery.

Adult↗