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Biomedical subjects

A Dueñas

Publications and source records attributed to A Dueñas.

At least 19 recordsLinked to original sources

Bone mass and bone modelling markers in hypertensive postmenopausal women.

Numerous phosphocalcium alterations associated with bone mineral density in hypertension have been described, but very few studies assess them. This study assesses bone mass in hypertensive postmenopausal women and the hypertension influence determining both calcium homeostasis and bone turnover markers. Blood and urine samples were analysed for calcium metabolism-related parameters. Densitometry studies were conducted in the lumbar spine (L2-L4). Hypertensive osteoporotic women--selected from 82 women, with 22% osteoporosis prevalence, similar to the rate for the same age in the Spanish population--had significantly higher levels of body mass index (29+/-4 vs 26+/-4, P=0.019), calciuria (293+/-146 vs 210+/-116 mg/24 h, P=0.023) and calcium/creatinine ratio (0.33+/-0.2 vs 0.22+/-0.1 P=0.003) vs hypertensive nonosteoporotic women. No relation was found between systolic and diastolic blood pressure with bone mass. However, there was a negative osteocalcin correlation (r=-0.386, P=0.0001, and r=-0.242, P=0.033). Calciuria is associated with bone mass decrease in hypertensive women, and there is no relation between bone mass and blood pressure.

Adult↗

[Drug poisoning].

A review is made of acute poisoning by opiates and its treatment in the emergency services, bearing in mind the progressive decline in the number of cases presented with the arrival of new forms of their administration, as well as the presence of new addictive drugs that have resulted in a shift in consumption habits. Reference is also made to the way in which the different types of existing substances originated, with the aim of achieving a better understanding of their use and in order to administer the most suitable treatment when poisoning occurs. Cocaine poisoning is discussed, with reference to its clinical picture, diagnosis and treatment. The consumption of illegal drugs in our country has undergone a notable change in recent years, with heroin being relegated and the incorporation of cocaine, amphetamine derivatives such as "ecstasy" (MDMA), "liquid ecstasy" (GHB) and, to a lesser extent, ketamine. A review is made of cannabis and its derivates, from the history of its consumption and the preparations employed to the effects produced in the different bodily systems. A brief explanation is also given of its metabolites and its principal mechanisms of action. Finally, we comment on the effects of LSD and hallucinogenic mushrooms.

Acute Disease↗

[Alcohol intoxication].

Alcohol intoxication is the principal drug addiction in many countries of the world. It affects all age groups, both sexes and almost all social groups. Mortality associated with acute alcohol poisoning on its own is exceptional, but it can be an important factor if it coexists with recreational drugs. It is directly responsible for more than half of traffic accidents. Diagnosis is easy by means of anamnesis and clinical examination, and can be confirmed by determining the level of ethanol in the bloodstream. Supportive care is the best therapy in order to protect the patient from secondary complications. Methanol, or alcohol fuel, is used as a solvent, and can also be found as an adulterant of alcoholic drinks. Poisoning by oral means is the most frequent. Oxidized in the liver through dehydrogenase enzyme alcohol, toxicity is due to its metabolites, formaldehyde and formic acid. The clinical picture basically consists of cephalea, nausea, vomiting, hypotension and depression of the central nervous system. The optic nerve is especially sensitive, with total and irreversible blindness as a possible result. Ethylenglicol is used as a solvent and as an antifreeze; toxicity is due to an accumulation of its metabolites. The clinical picture includes symptoms that are held in common with methylalcohol intoxication. Kidney failure due to tubular necrosis and the deposit of oxalate crystals can occur.

Acute Disease↗

[Poisoning by foodstuffs, plants and mushrooms].

Food poisoning is defined as poisoning caused by any foodstuff or alimentary product that causes poisoning because it contains toxic substances, germs, metals, additives, hormones, etc. It forms an important part of Clinical Toxicology, although in the majority of statistics, alimentary toxic infections provoked by bacteria, protozoa and viruses are not classified as poisonings, since they are caused by germs, and are classified as infections. Reference is made within this subject to all types of pathologies due to food, with special emphasis given to botulism. The clinical picture of botulism is discussed in its different clinical forms, but above all in its adult form which is contracted through the consumption of undercooked or badly preserved foods; poisoning by fish and seafood. Also described are the toxicological pictures that can be caused by the consumption of plants containing toxic substances, framed by the different symptomologies they produce; finally, poisonings by mushrooms are set out according to the period of incubation and possible confusions.

Acute Disease↗

Light symptoms following a high-dose intentional L-thyroxine ingestion treated with cholestyramine.

Adult exposure to L-thyroxine has a wide range of presentations: most adults either do not develop symptoms or only become minimally symptomatic. Appropriate treatments after exposure to L-thyroxine have yet to be established. A 26-year-old woman with a suicidal intention was witnessed to ingest approximately 50 L-thyroxine tablets, each containing 0.1 mg L-thyroxine (total dose 5 mg). Cholestyramine was administered (4 g every 8 h p.o.). Vital signs were monitored every 6 h and the hormone levels (L-thyroxine and thyroid-stimulating hormone) every 24 h. The thyroxine levels increased, and the thyroid-stimulating hormone levels decreased, with a normalization of the L-thyroxine level on postingestion day 6. Hypertension, dysrhythmias, and delusions did not appear in our patient. Only distal tremor and diaphoresis appeared on day 1 after ingestion. Cholestyramine has been used in cases of iatrogenic hyperthyroidism, in patients with Graves' disease, and in patients with digoxin intoxications, with good responses in all cases and a low incidence of side effects. This case illustrates the potential utility of cholestyramine to treat L-thyroxine intoxications.

Adult↗

[Evaluation of exposure to carbon monoxide among kiosk vendors. Valencia, Venezuela].

OBJECTIVE: To study the level of exposure to carbon monoxide (CO), factors contributing to this exposure, and the exposure's potential effects on the health of vendors who have kiosks located on an avenue with heavy vehicular traffic in the city of Valencia, Venezuela. METHODS: We measured the concentration of CO in the air (CO-air) in 16 kiosks in Valencia and also determined the concentration of carboxyhemoglobin (COHb) in the blood of 20 individuals who worked in those kiosks. We also determined the COHb concentrations in a control group made up of 23 professors, students, and workers from Simón Rodríguez University, which is in a town some 120 km from Valencia, in a remote mountainous area without noticeable pollution. RESULTS: In seven of the Valencia kiosks (43.7%) the permissible CO-air limits were exceeded. Among the vendors experimental group there was no correlation between the concentrations of CO-air and of COHb. The COHb average for the experimental group (2.9%) was significantly higher than that of the control group (1.6%) and that of the permissible level, according to the analytical method used (< 1.5%). Of a group of symptoms possibly related to CO exposure that were assessed as to whether or not they occurred on a daily basis, all of these symptoms affected a larger percentage of individuals in the experimental group than in the control group. The most common of these symptoms among the experimental group were fatigue and strong headaches. CONCLUSIONS: While the vendors' COHb average does not seem alarming, the CO exposures found could have an adverse impact on these workers' health, especially if they suffered from cardiovascular disorders, or as the result of additive interactions with other environmental pollutants. We recommend carrying out additional studies with more frequent and extended measurements of air quality, to produce information that could be applied in efforts to prevent and control adverse CO health effects.

Adolescent↗

Evaluation of an immunocapture-agglutination test (Brucellacapt) for serodiagnosis of human brucellosis.

We evaluated the validity and the usefulness of a new test for the diagnosis of human brucellosis based on an immunocapture-agglutination technique. A total of 315 sera from 82 patients with a diagnosis of brucellosis, 157 sera from patients in whom brucellosis was suspected but not confirmed, and 412 sera from people living in rural areas with endemic brucellosis were studied. The seroagglutination test (SAT), Coombs anti-Brucella test, and Brucellacapt test were evaluated. All the initial sera from the 82 patients proved to be positive in Brucellacapt and Coombs tests, while only 75 (91.4%) were positive in the SAT. If a >/=1/160 diagnostic threshold titer was defined for the Brucellacapt test, Coombs test, and SAT, the sensitivities were 95.1, 91.5, and 65.8%, respectively. Taking the same diagnostic threshold titer for the 157 sera from the unconfirmed but suspected patients, the specificities of the Brucellacapt, Coombs, and SAT were 81.5, 96.2, and 100%, respectively; for the 412 control sera, the specificities were 99.0, 99.8, and 100%. The diagnostic efficiency (area below the receiver operating characteristic curve) of Brucellacapt was 0.987852 (95% confidence interval [CI], 0.95109 to 0.99286), very similar to the diagnostic efficiency of the Coombs test (0.97611; 95% CI, 0.94781 to 0.99146) and higher than that of SAT (0.91013; 95% CI, 0.86649 to 0.94317). The results of the Brucellacapt test were compared with those of the Coombs test (correlation coefficient, 0.956; P = 0.000) and SAT (correlation coefficient, 0.866; P = 0.000). The study shows very good correlation between the Brucellacapt and Coombs tests, with a high concordance between titers obtained in the two tests. Nevertheless, lower correlation and concordance were found between the Brucellacapt and Coombs tests when the results for titers of >/=1/160 were compared (0.692; P = 0.000). In acute brucellosis, the Brucellacapt and Coombs tests render positive titers of >/=1/160. When the titers are lower, they increase significantly in the following 30 days, despite the evolution of SAT titers. In contrast, Brucellacapt and Coombs titers are always high (>/=1/640) in brucellosis with long evolution, whether SAT titers are higher or lower than 1/160.

Adolescent↗

[Arterial hypertension in Cuba. General overview of the past 25 years].

A general overview of hypertension as a major health problem in Cuba in the last 25 years are presented. In the first period, 1974-1990 was created a National Hypertension High Commission by the Minister of Public and the First national program for prevention and Control of Hypertension in Cuba was launched. To define high blood pressure in adults 15 years and older the cut-off point was set at 160/95 mmHg. The prevalence found was 15% in urban areas and 7-8% in rural areas. The second period, 1991-1998 the original National program was re-evaluated in 1990 and 1995. The new blood pressure cut-off point was set at 140/90 mmHg. The prevalence increased to 30.6% in urban areas and 15% in rural areas and incidence of 2.5% annual. A total of 862,303 hypertensive patients were registry at the end of 1997 which represents less than 40% of the total number of possible hypertensive patients. A National Campaign was launched in 1998. In 9 months the preliminary reports were: 25% increase in prevalence, registry and follow-up of hypertensive patients 15 years old and older (8.5% to 12.5%); 92.9% of primary care doctors and 89.5% of primary care nurses received training; improvement in public education and social support; improvement in risk factor awareness in general public and improvement of hypotensive drugs availability and splygmomanometers supplies.

Cuba↗

Effect of 4-aminopyridine and 3,4-diaminopyridine on guinea-pig isolated ileum.

1. 4-Aminopyridine and 3,4-diaminopyridine produced concentration-dependent contraction on guinea-pig isolated ileum incubated in Tyrode solution. The EC30 values were 1.14 x 10(-4) and 1.39 x 10(-4) M, respectively. 2. Calcium channel blockers such as verapamil, diltiazem, nifedipine, flunarizine, and lanthanum chloride antagonized the contracting effect induced by 4-aminopyridine and 3,4-diaminopyridine in guinea-pig isolated ileum. 3. Diazoxide and atropine sulphate behaved similarly as antagonists of the contracting effect induced by 4-aminopyridine and 3,4-diaminopyridine in guinea-pig isolated ileum. 4. It is concluded that the aminopyridines exert their effects through the release of acetylcholine from parasympathetic nerve terminals.

4-Aminopyridine↗

[Sequential chemotherapy and radiotherapy in the treatment of locally advanced carcinoma of the head and neck].

In patients with non-resectable carcinoma of the head and neck, radiotherapy produces an average survival of 12 months. Neoadjuvant chemotherapy followed by radiotherapy has been shown to prolong survival and preserve organ structure and function, and to reduce systemic relapses in patients with advanced, resectable disease. An analysis was made of 35 patients treated with sequential chemotherapy and radiotherapy, 20 with non-resectable disease and 15 with resectable disease who refused surgery. Treatment consisted of 4 cycles of cisplatin + 5-fluoruracil in a 96-h continuous intravenous infusion in 16 patients, and the same treatment with leucovorin in 19 patients. After chemotherapy, the patients underwent cobalt irradiation of the primary tumor and neck. Chemotherapy produced a complete response rate of 46% and a partial response rate of 28%, yielding an overall rate of 74%. After radiotherapy, the CR increased to 63%. After 92 months of maximum follow-up, overall survival was 20% and median survival was 25 months. Locoregional relapses were the main cause of treatment failure. Our results suggest that sequential chemo-radiotherapy achieved encouraging CR rates with no significant increase in toxicity, prolonged survival in non-resectable patients, and enabled organ preservation in patients with resectable disease.

Adult↗

An X-protocol based medical teleconsultation system using low or high speed networks. A specific-design approach.

The objective of this proposal is to provide solutions for the necessities of teleconsultation or telediagnosis among medical professionals, using work stations within the X-Windows environment and applicable in communication lines with an extensive range of bandwidths and operating system independence. Among the advantages sought are savings in transportation, improvement in the quality of the medical attention provided and continued training for the medical professional.

Computer Communication Networks↗

An ODA-based coder/decoder for multimedia medical documents.

This paper describes the prototype of a coder/decoder based on the Open Document Architecture (ODA) standard for management of medical documents, as well as the working environment in which it has been developed. The prototype has been assessed in an X-Windows-equipped workstation with a relational database containing patient folders (text and still images) from the departmental information system of the liver transplantation unit.

Humans↗

Effects of several neuroleptics, antidepressants and monoamine uptake blockers on ATPase activity and related oxygen uptake in rat brain in vitro.

An experimental trial was conducted to study the effects of phenoxybenzamine, cocaine, carbamazepine, loxapine, clozapine, clothiapine, thiothixene, droperidol, alprazolam, imipramine, maprotiline, dibenzepin, nomifensine, trazodone, mianserin, viloxazine, doxepin and amoxapine on photocolorimetrically rated ATPase activity and on related oxygen uptake, determined by manometrical means, within a concentration range of 0.1-0.001 mM. Phenoxybenzamine, clothiapine and maprotiline at 0.1 mM inhibited sodium-potassium ATPase activity and related QO2 by 30-40%. Loxapine, trazodone, amoxapine and alprazolam at 0.1 mM inhibited sodium-potassium ATPase activity by 25-35%. Imipramine, nomifensine and droperidol at 0.1 mM inhibited QO2 by 20-35%. Cocaine, at all concentrations assayed, inhibited ouabain insensitive ATPase. The remaining drugs did not produce significant modifications.

Adenosine Triphosphatases↗