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Biomedical subjects

E Villanueva

Publications and source records attributed to E Villanueva.

At least 19 recordsLinked to original sources

Sudden cardiac death: a comparative study of morphological, histochemical and biochemical methods.

The study deals with the comparison of morphological, histochemical and biochemical methods applied to the detection of myocardial infarction in 150 medico-legal autopsies performed at the Institute of Forensic Pathology in Copenhagen. The study also included an NBT (formazan) test of cardiac cross-sections, and light microscopy and fluorescence microscopy of acridine orange-stained specimens from four different sites of the cardiac musculature. Specimens of myocardium from the same four sites and pericardial fluid were analysed biochemically at the Institute of Legal Medicine in Granada. The K+/Na+ ratio was determined in the myocardial tissue and total creatine phosphokinase activity, creatine phosphokinase isoenzymes (MM, MB and BB) and myoglobin were assayed in pericardial fluid. When the results from Copenhagen and Granada were compared, there was absolute concordance in 96 cases, discrepancy in 53 and one case was inconclusive. After studying the circumstances of death, the number of discrepancies were reduced to 20, so that concordance was reached in 86% of all the cases. The results show that the combination of different methods leads to a diagnosis of myocardial infarction in far more cases than with morphological or biochemical methods alone.

Acridine Orange

Decrease of phosphofructokinase activity in relation to the pathogenesis of triorthocresyl-phosphate-induced delayed neuropathy.

The in vivo effect of a single dose of the neuropathic compound triorthocresyl-phosphate (TOCP) on phosphofructokinase (PFC, E.C. 2.7.1.11) and its relation with the initiation step (inhibition and aging of neuropathy target esterase, NTE) in the TOCP-induced delayed neuropathy have been studied. Hens were treated with a neurotoxic dose of TOCP (500 mg/kg, p.o.) and with a protective compound (Phenylmethanesulfonyl fluoride, PMSF, 30 mg/kg s.c.) in different combinations: TOCP, TOCP + PMSF, PMSF + TOCP and PMSF. PFK activity was determined in brain and sciatic nerve 1, 3, 7 and 15 days after treatment. PFK activity decreased in sciatic nerve 15 days after dosing with TOCP or TOCP + PMSF. When animals were dosed with the protective agent (PMSF) alone or before administering the neurotoxic compound, PFK activity was unaltered and clinical signs of neuropathy were absent. The data presented here suggest that phosphofructokinase is involved in the pathogenesis of the neuropathy induced by TOCP.

Acetylcholinesterase

[Characterization of Paracoccidioides brasiliensis antigens. Serological immunodiagnosis using western blotting].

The electrophoretic characterization on SDS-PAGE gels of Paracoccidioides brasiliensis antigens, strains 2511 and 6688; and the additional use of immunoblotting has permitted in this study to identify the immunogenic, sensitive and specific antigen fractions for the diagnosis of Paracoccidioidomycosis. The antigenic preparations showed differences depending on the morphologic form of the fungus and the method utilized. The procedure revealed heterogeneity in the humoral immune response of the patients studied and permitted us to establish indices of activity of Paracoccidioidomycosis by the sequential analysis of sera obtained during different stages of the disease. The high sensitivity of this method makes it useful as an additional technique for the serologic immunodiagnosis of Paracoccidioidomycosis.

Antibodies, Fungal

[Serotyping of 48 isolates of Candida albicans: predominance of serotype A over B in Venezuela].

The study of serotyping of isolates of Candida albicans of clinical material obtained from different geographic areas of Venezuela suggest that serotype A is predominant over type B. These results are in relation with results obtained in other countries. Type A serotype is predominant in 57 to 100% in the areas studied. Only in 2 cities serotype B was isolated. Both serotypes of Candida albicans were observed in intertriginous, mucosal, inguinal and lung forms. These studies have allowed us to have information about the predominance of serotypes in certain areas of the country.

Agglutination Tests

Postmortem stability of lung surfactant phospholipids.

The postmortem stability of the main phospholipids of lung surfactant-phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI), phosphatidyl serine (PS) and sphingomyelin (S) in three different deaths; one caused by fresh-water drowning, one by salt-water drowning, and one from a sodium-pentobarbital overdose has been studied. The drug overdose was considered the control because there was no surfactant involvement. The results show the stability of these kinds of lipids in the first 24 h, with a progressive decrease from 48 h on until 96 h, with a significant correlation to the time of P less than 0.01 in most cases.

Animals

A fatal case of oral ingestion of methanol. Distribution in postmortem tissues and fluids including pericardial fluid and vitreous humor.

A 41-year-old man ingested orally a large quantity of methanol and was found dead at home. The presence of methanol in body fluids and tissues was determined by head-space gas chromatography. The blood ethanol and acetone were negative. Tissue distribution of methanol showed that the kidney presented the highest content of methanol (5.13 g/kg) followed by liver (4.18 g/kg), vitreous humor (3.96 g/l), heart (3.45 g/kg), urine (3.43 g/l), pericardial fluid (3.29 g/l), blood (2.84 g/l) and finally stomach content (2.21 g/l).

Adult

Plasmatic levels of atrial natriuretic peptide (ANP) in drowning. A pilot study.

Bodies found in water may cause problems for forensic pathologists who have to differentiate drowning from postmortem immersion or fresh from salt water drowning. The exact physiopathology of drowning is still controversial and complementary tests can not exactly establish the exact cause of death if macroscopic findings at autopsy are not conclusive. We have employed atrial natriuretic peptide (ANP) as a marker in an experimental series of fresh and salt water drowning, comparing their results with a non-drowned control series. There are differences between the plasma basal levels of the control series (79 pg/ml) and the levels in animals drowned in fresh water (358 pg/ml, P less than 0.001) and between control and rabbits drowned in salt water (190 pg/ml, P less than 0.001). According to these values, there are also differences between fresh and salt water drowned animals (P less than 0.001). We propose this peptide as a new marker in cases of drowning, with the ability to differentiate drowning from postmortem immersion and fresh from salt water drowning.

Analysis of Variance

The usefulness of lung surfactant phospholipids (LSPs) in the diagnosis of drowning.

The authors have studied the usefulness of some lung surfactant phospholipids (LSPs) isolated from lung tissues as markers of drowning. Two different groups of rabbits were sacrificed by drowning in fresh and salt water, and their phospholipid compositions were compared with those of a non-drowned control series. For the phospholipids studied in lung lavages (phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidyl glycerol) the proportions differed between the control group and the drowned group, and between the fresh-water and salt-water drowned animals. According to these results, the lipids we have analyzed can be employed as markers in forensic autopsies, where it is necessary to differentiate between death by drowning and postmortem immersion and between fresh-water and salt-water drowning. In lung tissue, only phosphatidyl choline and phosphatidyl inositol showed significative differences. These results also confirm that LSPs are strongly affected in drowning.

Animals

[Significance of peroperative cholangiography in elective geriatric surgery of the bile ducts].

We present a retrospective study on the value of peroperative cholangiography (POC) in geriatric patients submitted to elective surgery of the biliary tract. We analyze the results of the present series and compare them with a previous study of 200 cases of cholelithiasis in the general population. Our conclusion is that in geriatric patients, POC should be a routine practice in order to avoid an unnecessary choledochotomy and/or residual lithiasis post-cholecystectomy.

Aged

Usefulness of different myocardial sampling zones for the postmortem diagnosis of myocardial infarction.

The diagnosis of myocardial infarction requires the use of a group of tests that are very efficient, quick and inexpensive. Another important consideration is the choice of myocardial sampling zones, especially in cases of differential diagnosis between a cardiac injury secondary to a trauma or violent asphyxia and others, secondary to myocardial infarction. The aim of this work was to choose, through discriminant analysis, the most useful zones of cardiac tissue for the quantification of free fatty acids and free carnitine and for the performance of the K/Na quotient, as biochemical parameters for the postmortem diagnosis of myocardial infarction. According to the discriminant analysis performed, seven zones of cardiac tissue are necessary to achieve a differential diagnosis among "myocardial infarction," "other natural deaths," and "violent deaths" with a 71.9% efficacy. Greater diagnostic efficacy was found (78.1%) for differentiating between "natural deaths" and "violent deaths."

Carnitine

Decreased phosphofructokinase activity during the development of triorthocresyl-phosphate-induced delayed neuropathy.

The effect of triorthocresyl phosphate on selected glycolytic enzymes (hexokinase, phosphofructokinase, glyceraldehyde 3-phosphate dehydrogenase, lactate dehydrogenase) was investigated during the development of organophosphate-induced delayed neuropathy. Only phosphofructokinase activity was decreased 15 days after treatment. The effect was dose-dependent and was observed in sciatic nerve while the brain enzyme activity was not affected.

Animals

Postmortem stability of some markers of intra-vital wounds.

We have studied the diagnostic value of several markers of the intra-vital nature of wounds - cathepsin D (EC 3.4.23.5) and ions (Ca, Mg, Cu, Zn and Fe) - after the influence of putrefaction. For this purpose, we have inflicted vital wounds to six pigs, which were killed 20 min later. Ten minutes after death, wounds were excised with 5-6 cm of skin around the incision and maintained at three different temperatures (4, 18 and 28.5 +/- 13.4 degrees C). After varying periods of postmortem interval from 0 to 48 h, aliquots of each wound were taken and analyzed with atomic absorption spectrophotometry for ions and with UV-spectrophotometry for cathepsin D. Our results demonstrate that ions conserve their diagnostic ability to differentiate vital from postmortem wounds after the influence of putrefaction. Nevertheless, cathepsin D does not show this ability in these experimental conditions.

Animals

Morphological diagnosis of sudden cardiac death.

The study reveals preliminary results of a bilateral project involving the Institute of Forensic Medicine, University of Copenhagen (Denmark) and the Institute of Legal Medicine, University of Granada (Spain). Morphological findings were compared to the results of thanatochemical analyses of pericardial fluid and myocardium in the same cases of sudden death of cardiac origin. Fifty cases were included, and the results of the macroscopic, histochemical, histological and cytological examinations revealed that the NBT test and microscopy are valuable methods in diagnosing infarctions, while cytological examination of pericardial fluid seems to be of no value.

Accidents, Traffic