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Biomedical subjects

A Arroyo

Publications and source records attributed to A Arroyo.

At least 55 records · Page 3Linked to original sources
PubMed1997

DMPS-arsenic challenge test. I: Increased urinary excretion of monomethylarsonic acid in humans given dimercaptopropane sulfonate.

The purpose of the present study was to evaluate in a novel manner the arsenic exposure of humans living in two towns in Northeastern Chile. Residents of one town drink water containing 593 microg As/l. Those in the control town drink water containing 21 microg As/l. Our hypothesis was that the administration of the chelating agent, 2,3-dimercaptopropane-1-sulfonic acid, Na salt (DMPS, DIMAVAL) would increase the urinary excretion of arsenic, alter the urinary profile of arsenic species and thus result in a better indication of the body load of arsenic and a better biomarker for arsenic exposure. The method used to evaluate these subjects was to give them 300 mg DMPS by mouth, after an overnight fast, and collect urine at specified time periods. The urine samples were analyzed for inorganic arsenic, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and total arsenic by hydride generation and atomic absorption spectrophotometry. The results indicated that: 1) During the 2-hr period after DMPS administration, MMA represented 42%, inorganic As, 20 to 22% and DMA, 37 to 38% of the total urinary arsenic. The usual range of the MMA percentage in human urine has been 10 to 20%. The % MMA increased almost equally for both the arsenic-exposed and control subjects. 2) The exposed subjects had a greater urinary excretion of total arsenic, before and after DMPS administration, than the control subjects. 3) Although buccal cells were obtained only from a few subjects, the prevalence of mononucleated buccal cells, an indication of genotoxicity, was 5-fold greater for those who consumed drinking water with the higher arsenic content than among control subjects. Our conclusions are that 1) DMPS has a highly specific effect in humans on MMA metabolism and/or urinary excretion; 2) the human body stores substantial amounts of arsenic; and 3) the urinary arsenic concentration after DMPS administration may be more indicative of the body burden of arsenic because it was greater than that found before DMPS was given.

Adult↗
PubMed1996

Congenital factor VII deficiency in a patient with an abdominal aortic aneurysm.

A patient with congenital factor VII deficiency underwent surgery for an inflammatory abdominal aortic aneurysm. No references in the literature have been found on the management of this coagulation defect in patients who require vascular surgery. We present one such case, with special reference to the perioperative management of factor VII replacement therapy.

Aged↗
PubMed1996

Ifosfamide and cisplatin as neoadjuvant chemotherapy for advanced cervical carcinoma.

A phase II trial was performed to evaluate the efficacy and toxicity of a combination of cisplatin (CDDP) and ifosfamide (IFX) as neoadjuvant chemotherapy in advanced cervical carcinoma (ACC). Between August 1991 and September 1993, 57 untreated patients with stages IIB to IVA were entered into this study. Median age was 44 years (range, 25 to 74 years). The distribution by stages (International Federation of Gynecology and Obstetrics) was as follows: IIB, 31 patients; IIIB, 21 patients; and IVA, 5 patients. Therapy consisted of IFX 2000 mg/m(2) 1-h i.v. infusion days 1 to 3; mesna 400 mg/m(2) i.v. bolus at hours 0 and 4, and 800 mg p.o. at hour 8; and CDDP 100 mg/m(2) on day 3. Cycles were repeated every 28 days for a total of three courses. Both staging and response assessment were performed by a multidisciplinary team. An objective response was observed in 30 of 56 patients (54%; 95% confidence interval, 41 to 67%). Four patients (7%) had a complete response (CR) and 26(46%) had a partial response (PR). Patients with CR or operable PR underwent surgery, otherwise received definitive radiotherapy. Toxicity was mild to moderate. There were no toxicity related deaths. These results indicate that IFX/CDDP is an active combination for ACC with mild toxicity. The results of phase III studies that evaluate the real impact of neoadjuvant chemotherapy are awaited.

Adult↗
PubMed1996

Parents' evaluations of wheezing in their children with asthma.

OBJECTIVE: Wheezing is a widely used physical sign of asthma that physicians assess in evaluation of their asthmatic patients. It may be possible to teach the parents to recognize it and to assess its severity so as to help them make better informed judgment in monitoring their children with asthma. STUDY DESIGN: Parents were taught to recognize wheezing by placing their ear over the chest and in front of the open mouth of their child. One session lasting a few minutes was sufficient for teaching. Subsequently, the parent and a physician evaluated the child independently for the presence and the severity of wheezing categorized as easily, barely, and none detected, and results were compared. Severity of wheezing was also compared with peak expiratory flow rate (PEFR) whenever possible. RESULTS: Six hundred thirty-six observations were made in 89 parent-child pairs. Wheezing was detected by the physician in 64% of examinations and by the parents in 56% (p < 0.001 by chi 2). When the physician heard the wheezing easily on 240 occasions, the parents also heard it in 99%. When the physician heard the wheezing barely on 170 occasions, the parents heard it only on 68% of the time. Mean PEFR was 55% predicted when the parents heard the wheezing easily, 75% when heard barely, and 93% when not heard (the difference is significant, p < 0.001 by analysis of variance). CONCLUSIONS: Parents can be taught to detect wheezing in their child with considerable accuracy when it is easily detectable to a physician. Such skills should be helpful to the parents in monitoring their child with asthma and in deciding when to increase medications and when to seek emergency care.

Adolescent↗
PubMed1995

Coenzyme Q reductase from liver plasma membrane: purification and role in trans-plasma-membrane electron transport.

A specific requirement for coenzyme Q in the maintenance of trans-plasma-membrane redox activity is demonstrated. Extraction of coenzyme Q from membranes resulted in inhibition of NADH-ascorbate free radical reductase (trans electron transport), and addition of coenzyme Q10 restored the activity. NADH-cytochrome c oxidoreductase (cis electron transport) did not respond to the coenzyme Q status. Quinone analogs inhibited trans-plasma-membrane redox activity, and the inhibition was reversed by coenzyme Q. A 34-kDa coenzyme Q reductase (p34) has been purified from pig-liver plasma membranes. The isolated enzyme was sensitive to quinone-site inhibitors. p34 catalyzed the NADH-dependent reduction of coenzyme Q10 after reconstitution in phospholipid liposomes. When plasma membranes were supplemented with extra p34, NADH-ascorbate free radical reductase was activated but NADH-cytochrome c oxidoreductase was not. These results support the involvement of p34 as a source of electrons for the trans-plasma-membrane redox system oxidizing NADH and support coenzyme Q as an intermediate electron carrier between NADH and the external acceptor ascorbate free radical.

Animals↗
PubMed1995

[Size and echogenicity of the pancreas in Chilean adults: echotomography study in 261 patients].

The aim of this work was to perform ultrasonographic measurements of normal pancreas in the Chilean population. Among 5000 subjects referred for an ultrasound abdominal examination, those without history of alcoholism, pancreatitis or liver disease were selected for the study. 261 individuals (157 female) aged 20 to 79 years were studied. The size of the head of the pancreas ranged from 6 to 28 mm (17.7 +/- 4.2 mm), the body size ranged from 4 to 23 mm (10.1 +/- 3.8 mm) and the tail size from 5 to 28 mm (16.4 +/- 4.2 mm). These figures are lower than those reported in Europe and North America. No size differences were observed according to sex or body frame. Progressive declines in size with age, were observed in all pancreatic segments. No hypoecogenic pancreas were observed. A new technique to improve pancreatic ultrasonographic vision is proposed.

Adult↗
PubMed1994

[The treatment of pneumothorax by small-caliber drainage without a water seal].

The authors describe their experience in treating 72 patients with pneumothorax by placement of a drainage tube of 2.2 mm internal diameter equipped with a Heimlich valve. Full lung expansion was achieved with this method in 93% of the cases. Mean hospital stay was 4.05 days (Sx = 3.4, minimum 1, maximum 20). In 7 (10.7%) cases out of 64 who were discharged and followed as outpatients, there was recurrence of pneumothorax. With these results the authors conclude that the system used is valid for treating pneumothorax and that large drains and water seals are not necessary in most cases.

Adult↗
PubMed1994

[Ultrasonographic images of gastroduodenal ulcer].

The ultrasonographic study of gastroduodenal lesions has received little attention. We report the results of ultrasound examination in 39 patients with gastric ulcer and 14 patients with duodenal ulcers, all endoscopically confirmed. We describe six varieties of ultrasonographic images that change with front or side views of the crater, according to the contents of the crater (liquid, sediment of air-mucus) and according to its localization (proximal or distal to the transducer). The importance of gastroduodenal segment exploration during ultrasound examination is emphasized.

Humans↗
PubMed1993

Transplasma membrane redox system of HL-60 cells is controlled by cAMP.

Transplasma membrane redox activity of HL-60 cells was determined by measuring the prevention of ascorbate chemical oxidation. The ascorbate free radical produced as the first step of ascorbate oxidation was reduced back by the transplasma membrane electron transport system, causing then the regeneration of extracellular ascorbate. Agents that increase intracellular cAMP, such as forskolin and dibutyryl cAMP (db-cAMP), increased the rate of ascorbate regeneration by HL-60 cells. Also, the phosphodiesterase-resistant cAMP analogue Sp-cAMP-S (agonist of the protein kinase A) increased the electron flow to the ascorbate free radical at the plasma membrane. Rp-cAMP-S, antagonist of the protein kinase A, partially inhibited the redox activity of cells and abolished the effect of Sp-cAMP-S. Inhibition obtained after preincubation of cells in Rp-cAMP-S was reversed by Sp-cAMP-S. Tunicamycin, a compound that inhibited the electron flow to the ascorbate free radical at the plasma membrane, also reduced the response of transplasma membrane redox system to Sp-cAMP-S. Lactate slightly affected the ascorbate regeneration in nonstimulated cells, but showed a significant effect on Sp-cAMP-S-stimulated plasma membrane electron flow. We show here a role for cAMP in the short-term modulation of transplasma membrane redox system measured as the regeneration of ascorbate at the cell surface of HL-60 cells, probably mediated by cAMP-dependent protein kinases.

Ascorbic Acid↗
PubMed1993

[The prevalence of mental illness in primary care and its relation to the degree of consultation frequency].

OBJECTIVE: To establish the prevalence of psychic malaise within the population that consults the general medical clinic of our health center and the relationship between that prevalence and the frequency of consultation. DESIGN: Transversal descriptive study applying the GHQ test (28 items) to a sample obtained by mathematical sampling, using a questionnaire to collect sociodemographic data. SITE. The Health Center Segovia II (La Albuera) during November and December 1991. PATIENTS OR OTHER PARTICIPANTS: 360 patients over the age of fifteen were selected; 252 answered the test. MAIN MEASUREMENTS AND RESULTS: Considering the GHQ test as positive when score seven or more, a prevalence of psychic malaise of 33% was obtained. We found a statistically significant relationship between positive GHQ test and the frequency of consultation (p < 0.001) and female gender (p < 0.01). No statistically significant relationship was found between psychic malaise and the following variables: age, marital status, educational level and occupation. CONCLUSIONS: There is a high prevalence of psychic malaise within the population attending our general practice which can produce an increase in the demand. A biopsychosocial approach to all patients, with the aim of identifying that kind of problem and approaching it adequately, could reduce the use of health resources.

Adolescent↗
PubMed1993

In vitro cytogenetic effects of 2450 MHz waves on human peripheral blood lymphocytes.

Cytogenetic analyses were performed on human peripheral blood lymphocytes exposed to 2450 MHz microwaves during 30 and 120 min at a constant temperature of 36.1 degrees C (body temperature). The temperature was kept constant by means of a temperature probe put in the blood sample which gives feedback to a microcomputer that controls the microwave supply. We found a marked increase in the frequency of chromosome aberrations (including dicentric chromosomes and acentric fragments) and micronuclei. On the other hand the microwave exposure did not influence the cell kinetics nor the sister chromatid exchange (SCE) frequency.

Adult↗
PubMed1992

[Echotomographic findings in gastric cancer].

Echotomographic studies were performed in 163 patients with gastric cancer from 1984 to 1990. The technical aspects of the examination and the images obtained in different lesions are described. Emphasis is placed on local or diffuse wall infiltration, ulcerations, vegetations or stenotic lesions. Consideration of these aspects during routine echotomographic exploration of the abdomen may help improve to the detection of gastric cancer.

Female↗
PubMed1992

[Percutaneous puncture thyroid cytology: cyto-histologic correlations in 136 nodular goiter surgical patients].

Percutaneous puncture for cytologic study was performed in 136 patients with nodular goiter. All patients were operated on and correlation of cytologic and histologic findings was obtained. Echographic study revealed a solid aspect in 72%, cystic aspect in 10% and mixed in 18%. The cytologic findings were classified as: benign--hyperplasia--, chronic thyroiditis, follicular neoplasm (adenoma and carcinoma), oxyphilic neoplasm (adenoma and carcinoma), papillary cancer, medullary cancer, anaplastic cancer and insufficient material. Surgery revealed cancer in 36 patients (26.5%). There were 3 false positives for cancer in the cytologic study. Percutaneous cytology was able to detect 88% of patients with cancer and 83% of patients with neoplasms. False negatives for cancer (n = 5) were due to insufficient sample (2), topographic error (2) and cytology error (1). No follicular cells were obtained in 13 patients with cystic follicular adenoma and the diagnosis was missed. Surgery confirmed that 24 of 25 patients with cystic aspect on echography had a basic underlying lesion. Thus, percutaneous cytology of the thyroid is useful in the evaluation of patients with cold nodules. Main limitations of the technique are found in patients with cystic lesions and follicular neoplasms.

Adolescent↗
PubMed1991

Campomelia, polycystic dysplasia, and cervical lymphocele in two sibs.

We report on 2 sibs with a similar MCA pattern consisting of generalized lymphedema, cervical lymphocele, shortness of limbs, bowed long bones, and multicystic kidneys with fibrotic liver or pancreas. To our knowledge, this is the second observation of such a combination of defects in sibs, and it confirms the existence of the syndrome reported by Cumming et al. [1986] and its autosomal recessive inheritance.

Abnormalities, Multiple↗