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P Cabrera

Publications and source records attributed to P Cabrera.

At least 37 records · Page 2Linked to original sources
PubMed1994

Value of DNA analysis in addition to cytological testing in the diagnosis of malignant pleural effusions.

BACKGROUND: Aneuploidy appears to be a highly specific marker for cancer, and measurement of cellular DNA content by flow cytometry is rapid and reliable. This study was undertaken to determine if the addition of DNA analysis improved the sensitivity of cytological diagnosis of malignancy in pleural fluid. METHODS: Pleural effusions from 92 patients were studied by cytological examination and flow cytometry. RESULTS: In 41 patients the final diagnosis was malignancy, there were 40 cases of benign effusions including 22 with pleural tuberculosis, and in the remaining 11 patients with biopsy proven cancer the presence of malignant cells was not found by cytological and histological means in the pleural fluid. Aneuploidy and cytological malignancy were found in 14 samples. There were seven cases with abnormal flow cytometry and negative cytological results. In 12 patients the cytological test results were positive but DNA analysis was normal. Thirty six samples of fluid were both diploid and cytologically negative. Of the 22 tuberculous effusions seven contained aneuploid cells. The sensitivity of DNA and cytological analysis was 51.2% and 63.4%, respectively. The specificity of DNA analysis was 74.5%. CONCLUSIONS: DNA analysis of cells in malignant pleural effusions is both less sensitive and specific than the cytological diagnosis. Flow cytometric analysis is not recommended for routine use in the diagnosis of pleural effusions.

Adolescent↗
PubMed1994

Value of ELISA using A60 antigen in the serodiagnosis of tuberculosis.

This study was set in a general, university hospital in the Canary Islands, with the objective to evaluate an enzyme-linked immunosorbent assay (ELISA) using A60 in the serodiagnosis of tuberculosis. IgG antibody to A60 was determined in 205 patients with active disease [149 culture-positive patients with pulmonary tuberculosis (positive sputum smear 94, negative sputum smear 55) and 56 patients with extrapulmonary tuberculosis], 20 patients with inactive disease, 22 patients with lepromatous leprosy, and 51 controls. The mean levels of anti-A60 antibodies were significantly higher in patients with active disease as compared with controls or patients with inactive disease. Differences were also found between tuberculous patients with pulmonary and extrapulmonary disease. In patients with pulmonary disease, significant differences were detected between smear-positive and smear-negative patients. The overall sensitivity of the test (cutoff 240 ELISA units) was 52.2%. The highest sensitivity was found among smear-positive patients with pulmonary tuberculosis (67%) and the lowest among those with extrapulmonary tuberculosis (32.1%). We conclude that ELISA for the measurement of IgG antibody to Mycobacterium tuberculosis antigen A60 could be of interest, specially in smear-negative cases and extrapulmonary tuberculosis.

Adult↗
PubMed1993

Serum antibodies in canine echinococcosis.

Specific IgG, IgA and IgE antibodies against E. granulosus protoscolex antigen were detected by enzyme-linked immunosorbent assay (ELISA) in sera from dogs experimentally or naturally infected with E. granulosus. The specificities of the IgG, IgA and IgE ELISAs were 100, 100 and 97.3%, respectively. Sera from 626 dogs of different categories and geographic regions in Australia, Uruguay and Kenya were tested. There were distinct differences in antibody responses in experimentally infected canids and in the number of naturally infected dogs found seropositive, depending on geographic region. The overall sensitivities of the ELISA (IgG, IgA and IgE) ranged between 73 and 84%, except for one geographic region where it was 54%. Genetic differences of the dogs and/or antigenic variations of the parasite appear to be responsible for the variations in specific antibody levels in infected dogs. In average, approximately one third of dogs from hyperendemic hydatid regions, without E. granulosus worms at autopsy or negative for E. granulosus infection by arecoline testing, were seropositive for anti-E. granulosus antibodies, suggesting previous infection with or exposure to the parasite. The results of this study demonstrate that, although the diagnosis of current intestinal E. granulosus infection on an individual dog basis is not always reliable by serology, serum antibody ELISA is useful as an epidemiological/educational tool for seroprevalence studies on canine echinococcosis.

Animals↗
PubMed1993

Diagnosis of pleural tuberculosis by detection of specific IgG anti-antigen 60 in serum and pleural fluid.

The objective of this study was the prospective evaluation of the IgG antibody levels to mycobacterial antigen 60 (A60) in serum and pleural fluid and their role in the diagnosis of tuberculous pleuritis. The level of IgG was measured by Elisa in 30 patients with tuberculous pleuritis and 48 control subjects with pleural effusion (24 with carcinoma, 10 with transudative pleural effusion, 11 with empyema or parapneumonic effusion, 1 with pulmonary embolism and 2 due to systemic lupus erythematosus). The median titers of IgG against A60 of both serum and pleural fluid from tuberculous patients [445.6 +/- 133.56 and 263 +/- 72.58 Elisa units (EU) respectively] were significantly higher than those of corresponding median values (97.3 +/- 8.35 and 41.3 +/- 4.93 EU) of the control group (p < 0.01 and p < 0.01, respectively). Considering 240 units as cutoff point for a positive test in serum, the sensitivity was 53.3% and the specificity 100%. In the pleural fluid the cutoff point value was established at 150 units, with a sensitivity of 50% and specificity of 100%. We concluded that Elisa using A60 is a reliable and rapid test with an acceptable sensitivity and magnificent specificity.

Antibodies, Bacterial↗
PubMed1991

[Epidemiology of tuberculosis in the Gran Canary Island].

BACKGROUND: The aim of the present study was to obtain information about tuberculosis (TB) in our area that might contribute to assess the status in Spain. METHODS: A meticulous case finding was carried out during 1988 in all the hospitals of the Gran Canaria island. RESULTS: 214 cases were found (rate 32.2) and 77% were admitted to hospitals. In 160 (74%) the involvement was pulmonary and in 82 (37%) it was extrapulmonary. Mean age was 34 years (range 1-84) and 62% were younger than 40 years. 69% were males. Complete data were obtained in 183 cases (85%). 56% were smokers, 34% alcoholic abusers, 15% drug abusers (35% parenteral) and 4% homosexuals. 26% had some risk factor for TB; 14 of them had been infected by the HIV (8 had AIDS). In 64% there was a diagnostic delay longer than one month. Out of the 214 cases, the diagnosis was made by direct microscopy and/or culture in 110 (51%), by consistent pathological findings in 41 (19%), with some of these studies but with negative results in 35 (16%) and only with clinical and radiological criteria in 28 (13%). 96 (60%) of the pulmonary cases had cavitation. The most common therapeutic schedule (84%) was the recommended 9-month regimen. In 54% no recommendation for the investigation of contacts was made. CONCLUSIONS: In the authors' area, the prevalence of TB is higher than in developed countries. It is more common in middle aged individuals, many diagnoses are still made without bacteriologic studies and in a high number of cases investigation of contacts is not carried out.

Adolescent↗
PubMed1991

Effect of cigarette smoking on the humoral immune response in pigeon fanciers.

Tobacco smoking is associated with increased prevalence of various diseases. In this study, we have used an indirect enzyme-linked immunosorbent assay (ELISA) to investigate the specific IgG response to pigeon serum and its relationship to tobacco smoking. In a large group of pigeon fanciers the development of pigeon breeder's disease and some of the clinical features were also investigated. We found a sensitization rate of 31.9%, a lower degree than that found by other authors, in spite of using a less specific antigen. We also found that fanciers who are current cigarette smokers had significantly lower levels of IgG antibody to pigeon serum (P less than 0.001). Finally, 11.9% of the population had chronic bronchitis as their only manifestation of possible pigeon-related disease. 19.6% of the sensitized fanciers had chronic bronchitis, were non-smokers and had no other risk factor for developing chronic bronchitis.

Adolescent↗
PubMed1991

Allergy to limpet.

Allergy to mollusk has rarely been described. The limpet, belonging to Phylum mollusca, is one of the most frequent mollusks in the Canary Islands, as in all warm maritime regions. We report two cases of atopic patients who developed anaphylactic reactions after ingestion of this mollusk. Type I hypersensitivity to limpet antigens was demonstrated by means of immediate skin test reactivity, specific IgE determination by RAST, and histamine release test to cooked limpet extract. The controls did not react to any of these tests. Allergic activity was only found with a cooked limpet extract; this suggests that the offending antigen/s may have been released by cooking this food.

Adult↗
PubMed1990

Dose-effect study of intranasal administration of growth hormone-releasing hormone-44-NH2 in healthy subjects.

Intranasal (in) administration of GH-releasing hormone-40- (GHRH-40) has been demonstrated to be efficient in stimulating GH secretion at doses equal to or higher than 30 micrograms/kg in man. We performed a dose-response study with GHRH-44-NH2 (GHRH) given by nasal spray and closely monitored local tolerance. Twelve normal young men were given 5 GNRH doses (125, 250, 500, 750, and 1000 micrograms) and placebo in random order according to a latin square design. Mild symptoms of local intolerance, subjective, objective, or both, were noted in the first 20 min after spray in 30 of 72 tests, and a significant difference (P = 0.003) was obtained in their frequency between the group placebo plus the lowest dose and the group of the other doses. The areas under the GH curves were significantly different between the subjects and the doses (by analysis of variance, P = 0.001 and P = 0.025, respectively). Multiple comparison tests showed a significant difference between the 3 highest doses and the placebo (P = 0.005, P = 0.05, and P = 0.02, respectively) and a significant difference between the highest dose and the 2 lowest doses (P = 0.005). By weighted linear regression between GH areas under the curve and GHRH doses the dose-response relationship was established as: y = 1.226x + 457. The magnitude of the GH peaks induced by in GHRH was significantly lower than that induced by iv GHRH. We conclude that in the normal young men tested, who were high responders to GHRH (as demonstrated by iv test), a 500-micrograms dose is sufficient to elicit GH secretion. Local tolerance, although imperfect, appears satisfactory to permit a clinical trial in children.

Administration, Intranasal↗
PubMed1989

Effects of the somatostatin analog BIM 23014 on the secretion of growth hormone, thyrotropin, and digestive peptides in normal men.

BIM 23014 (BIM) is a long-acting octapeptide somatostatin analog. We studied the effects of this analog on the secretion of GH, TSH, and gastroenteropancreatic hormones [secretin, motilin, and pancreatic polypeptide (PP)] in normal men. In the first protocol three BIM doses (125, 250, and 500 micrograms) and vehicle were administered sc in random order at 2000 h to eight normal young men. Plasma GH concentrations decreased during the first part of the night only after the highest dose (P less than 0.05). Plasma secretin levels did not change, while plasma motilin decreased after the 250- and 500-micrograms doses (P = 0.05 and P = 0.02, respectively), and plasma PP decreased after all three doses (P less than 0.05, P less than 0.01, and P less than 0.01, respectively) during the first part of the night. In the second protocol, eight men received BIM, administered by constant sc infusion during the night in a dose of 2 mg/12 h, or vehicle, either alone or in association with a 10 ng/kg.min iv GHRH or vehicle infusion. Nocturnal GH secretion was suppressed by the BIM infusion (P less than 0.001). GH secretion, stimulated by GHRH infusion (P less than 0.001), was reduced by concomitant BIM infusion (P less than 0.001) and was pulsatile during the combined infusions. BIM infusion suppressed the physiological nighttime rise in plasma TSH levels. Plasma motilin and PP levels were reduced by BIM, when administered either alone or in combination with GHRH. We conclude that: 1) BIM is capable of reducing GH secretion when administered sc in a dose of 500 micrograms and of abolishing nocturnal GH secretion when constantly infused at a dose of 2 mg/12 h; 2) BIM, constantly infused, reduces the nocturnal rise in TSH secretion; and 3) motilin and PP secretion are more sensitive than that of GH to BIM, as they are reduced by a lower dose.

Adult↗
PubMed1987

Pharmacokinetics of human growth hormone releasing factor (hGRF-44 NH2) in normal men after intravenous administration of a large range of doses.

Three ranges of doses of growth hormone releasing factor (2.5-80 micrograms, 80-320 micrograms and 75-600 micrograms) were intravenously administered to healthy young volunteers in three double blind studies. Serum circulating GRF levels were determined by radioimmunoassay. Experimental concentration curves were fitted, using the extended least squares method, to a biexponential model for the structural model and power function for the variance model. The power variance model, compared to the constant variance model greatly reduced the coefficient of variation of the biexponential parameters. The power of the variance model was estimated to be 1.95. The distribution half-life was 6.6 min and the elimination half-life was 39.0 min (harmonic means). Total clearance was 0.12 +/- 0.01 microgram/l/min. No difference between these parameters was found for the various doses. GRF kinetics was linear established in the range 10 to 600 micrograms which means that elimination was not altered by the increased doses.

Adult↗
PubMed1987

Pulmonary ceroidosis.

We describe a patient with pulmonary ceroid histiocytosis. Skin pigmentation, chest x-ray film and laboratory findings were normal. Only pulmonary function tests were abnormal (TLC = 63 percent, DLco = 52 percent). Based on these functional data, the patient was submitted to a lung biopsy by thoracotomy. Brown pigmented histiocytes were shown occupying alveolar spaces. Similar brown pigmented hepatocytes were seen in the liver biopsy.

Adult↗
PubMed1986

Pituitary stimulation by combined administration of four hypothalamic releasing hormones in normal men and patients.

Ten normal young men (22-28 yr of age), within 10% of their ideal body weight, were given the four releasing hormones (TRH, 200 micrograms; GnRH, 100 micrograms; ovine corticotropin-releasing hormone, 50 micrograms; GH-releasing hormone, 80 micrograms) iv on separate days and then in combination on the same day. Plasma TSH, PRL, FSH, LH, cortisol, ACTH, and GH were measured by RIA in samples collected from 20 min before to 120 min after injection. There were no significant differences in responses to the separate and combined tests for FSH, LH, cortisol, ACTH, and GH. The plasma TSH (0.001 less than P less than 0.01) and PRL (P less than 0.001) responses were significantly higher after the combined test. The tolerance was identical to that of TRH alone. In eight patients studied after pituitary surgery, combined administration provided results comparable to those obtained after separate administration of TRH, GnRH, and insulin.

Adenoma↗
PubMed1986

Nocturnal continuous infusion of growth hormone (GH)-releasing hormone results in a dose-dependent accentuation of episodic GH secretion in normal men.

Fluctuations in plasma GH levels have been found in patients with acromegaly who have continuously elevated levels of ectopically produced GH-releasing hormone (GHRH). Likewise, plasma GH fluctuations have been found in normal subjects receiving continuous GHRH infusions. We report the effects of two doses of GHRH, administered by constant infusion, on nocturnal GH secretion in six normal young men. Each received, in random order, 2.5 ng/kg X min GHRH, 15 ng/kg X min GHRH, and 0.15 M NaCl. During both GHRH doses, a highly significant increase in total nocturnal GH secretion was found (P less than 0.001) as well as an increase in GH secretion during different periods of the night. Nocturnal GH secretion was episodic during the GHRH infusions, with an increase in the number and magnitude of the peaks compared to those during the NaCl infusion. Plasma immunoreactive GHRH concentrations plateaued at 1 h during the high dose and at 3 h during the low dose GHRH infusion. Sleep parameters, including total sleep time, sleep latency, and duration and timing of the different sleep stages, were not affected by GHRH infusions. We conclude that GHRH, continuously infused, increases nocturnal GH secretion according to the dose, while the episodic pattern of GH secretion is maintained.

Adult↗