Immunohistochemical detection of fibronectin and tenascin in incised human skin injuries.

Immunohistochemical detection of molecules involved in inflammatory reaction can be useful for the diagnosis of vitality in skin wounds. We studied the expression of fibronectin (FN) and tenascin (TN) in 58 human skin wounds (48 vital and 10 postmortem). The age of vital injuries ranged from 3 min to 8 h and postmortem specimens were collected after a postinfliction interval of 15-180 min. One hundred thirty-seven formalin-fixed paraffin-embedded sections (mean: 2.3 sections per case) were stained with each of two monoclonal antibodies against FN and TN using the streptABC technique. A reticular staining for FN in wound edge and dermis was observed in 50% of vital specimens versus 0% in postmortem cases. Immunoreactivity was reduced in 10 autolysed cases. FN positivity exclusively at the injury margin was observed in 39.4% of vital wounds and 10% of postmortem cases. TN was negative in all specimens. Vital and postmortem hemorrhage areas showed positivity for FN and TN. Due to its low sensitivity, immunohistochemical analysis of FN is useful for determining vitality only in a minority of cases. Different factors in everyday practice, including autolysis and technical problems often produce false negative reactions with the result that FN cannot be regarded as a reliable parameter of vitality. Positive reactions (network staining) are more valuable than negativity but are not pathognomonic. Both vital and postmortem hemorrhages show an enhanced positivity for FN and TN, thus impeding the diagnosis.

A new spectrophotometric method for the toxicological diagnosis of cyanide poisoning.

A spectrophotometric method for the determination of hydrogen cyanide in biological fluids based on the release of cyanide ion by the addition of a strong acid and its subsequent specific reaction with hydroxocobalamin to give cyanocobalamin is proposed. The release of cyanide ion is accelerated by aeration with a stream of an inert gas (nitrogen) that carries it into the hydroxocobalamin solution. Although the in vitro reaction develops to completion within 20 min, reproducible quantitation in biological media takes 45 min. The cyanocobalamin formed is quantitated by second-derivative visible spectrophotometry from the absorbance difference between 333 and 361 nm, the measured signal being proportional to the cyanide ion concentration in the sample.

Unexpected sudden death from coronary sinus thrombosis. An unusual complication of central venous catheterization.

Coronary sinus thrombosis is an unusual but potentially serious complication of the use of central venous devices. We report a fatal case of coronary sinus thrombosis in relation to a malpositioned central venous catheter. The death occurred very soon following the beginning of symptoms and the cause could not be suspected. Direct trauma of the catheter on the coronary sinus endothelium seems the most probable cause of the thrombosis.

[The legibility of written informed consent forms]. / Legibilidad de los formularios escritos de consentimiento informado.

BACKGROUND: The generation of the use of informed consent forms makes necessary to grant their legibility for patients. Up to now, we didn't have in Spain a suitable yardstick for evaluating the reading levels. METHODS: A sample of 10 texts of diverse procedence, 8 journals and 16 informed consent forms were collected. They were analyzed using the Grammatik 6.0 utility of the word processor Word Perfect 6.1, and four parameters were obtained: number of words, number of sentences, Flesch-Kincaid Grade Level and Sentence Complexity. In addition an Integrated Readability Level (LEGIN) was calculated. RESULTS: Flesch Level and Sentence Complexity give a suitable and complementary analysis of readability, which is enhanced by the LEGIN. The acceptably reading level is obtained when the Flesch-Kincaid Level is above 10, the Sentence Complexity is under 40 and, overcoat, the LEGIN is above 70. Just 5 of the 16 consent forms had the adequate LEGIN level. Another 5 had the Flesch correct levels and 7 the adequate Sentence Complexity. CONCLUSIONS: The Grammatik utility of the word processor Word Perfect 6.1 is a suitable yardstick to analyze the readability, but is necessary to complete the analysis with the LEGIN, to render more sensibility and especificity. It's mandatory to enhance the readability of written forms to grant the ethical quality of the informed consent process.

[Evaluation of various criteria for the interpretation of western blot for the diagnosis of human immunodeficiency virus infection. Spanish Group for the Study of HIV-2]. / Evaluación de diferentes criterios de interpretación del Western blot para el diagnóstico de la infección por el virus de la inmunodeficiencia humana. Grupo Español para el Estudio del VIH-2.

BACKGROUND: The Western blot (WB) is the most commonly used test to confirm the presence of antibodies against the human immunodeficiency virus type 1 (HIV-1). Different criteria of interpretation of the band profile have been proposed with there being no unanimity as to its reliability. The sensitivity and specificity of several criteria proposed for the interpretation of WB were evaluated and the individual significance of the reactivity of each band of the WB was analyzed. METHODS: The presence of antibodies against HIV-1 was prospectively studied in 8,073 samples of subjects with risk of infection. A total of 1,993 (25%) were reactive by ELISA and 1,261 were analyzed by WB, with a semiquantitative reading of the bands with a point scale from 0 to 2 being performed. The final interpretation of the WB (negative, doubtful, or positive) was carried out following 5 recommendations of usage. A test designed with synthetic peptides (Pepti-lav) was used as a reference and in discordant cases, other more specific serologic tests and/or genetic analysis by polymerase chain reaction (PCR) were performed. RESULTS: In order of frequency, the greater sensitivity was found to be for the CRSS (Consortium for Retrovirus Serology Standardization) criteria (97.9%), OMS (96.6%), CDC (Center for Disease Control) (95.9%), ARC (American Red Cross) (95.6%) and FDA (99.8%). The greatest specificity was for the criteria of the OMS, and FDA (99.8%). In order of frequency, the most frequent bands in HIV-1 + individuals were gp160 (99%), gp120, p24, p31, p55, p68, gp41, and p17 (68%). In non infected individuals, the recognized bands were, in decreasing order, p24, p17, p55, p68, p31, and glucoproteins. CONCLUSIONS: Different criteria of interpretation of the Western blot provide different degrees of sensitivity and specificity. The Western blot is a non standardized, expensive, laborious technique of subjective interpretation which provides an appreciable number of undetermined results.

Longstanding intracardiac catheter embolism. An unusual autopsy finding.

The use of central venous catheters has greatly increased and so has the incidence of major complications. Catheter tip embolism is especially hazardous and sometimes may be fatal. We report a case of sudden death as a late and unusual complication of a catheter fragment embolism. The patient, a 39-year-old alcoholic man, suffered a nonreversible cardiac arrest shortly after his admission to hospital. Autopsy revealed a 54-cm-long fragment of an intravenous catheter in the right ventricle and the pulmonary trunk. Death was attributed to a cardiac arrhythmia.

Planned complex suicide. An unusual suicide by hanging and gunshot.

We report a case of planned complex suicide (PCS) by a young man who had previously tried to commit suicide twice. He was found dead hanging by his neck, with a shot in his head. The investigation of the scene, the method employed, and previous attempts at suicide altogether pointed toward a suicidal etiology. The main difference between PCS and those cases defined in the medicolegal literature as combined suicides lies in the complex mechanism used by the victim as a protection against a failure in one of the mechanisms.

A fatal case of suicidal pentoxifylline intoxication.

Pentoxifylline is a xanthine derivative used in the treatment of peripheral vascular disease. It is considered to be a safe drug and to the best of our knowledge there are no reports in the medical literature of cases of fatal poisoning. There is only one previous report of a young woman who tried to commit suicide by taking a large amount of the drug but recovered. We report the case of a 54-year-old man who took a massive dose of pentoxifylline and died after 24 h from refractory shock. The blood levels of pentoxifylline were as high as 32.5 micrograms/ml where the average therapeutic level is 1.3 micrograms/ml.

Expression of fibronectin and tenascin as a demonstration of vital reaction in rat skin and muscle.

The efficiency of immunohistochemical techniques for the diagnosis of vitality of wounds decreases for lesions occurring fairly close to death. We analyzed the expression of fibronectin (FN) and tenascin (TN) in wounds inflicted in abdominal skin of 12 adult rats. An incised injury was made at 5, 10 or 15 min before death and another at 5 min after sacrifice, and collected after 45 min. Formalin-fixed paraffin-embedded sections from a total of 36 samples (mean 1.5 per wound) were immunostained following the streptABC technique. Microscopic examination revealed a reticular pattern staining in 18 out of 20 vital samples for FN, 16 out of 20 for TN, 2 out of 16 postmortem samples for FN and 3 out of 16 for TN. Intracellular staining of muscle fibres was observed in 7 out of 20 vital and 5 out of 16 postmortem samples. FN and TN were detected in most of the vital injuries but they are not completely specific. Postmortem staining occurred in a few cases probably related to a passive extravasation of these molecules from damaged blood vessels. Reactivity of muscle fibres occurs both in vital and postmortem lesions, and is not useful in the diagnosis of vitality.

Sudden neonatal death from congenital cystic adenomatoid malformation.

We report a case of congenital cystic adenomatoid malformation (CCAM) of the lungs resulting in sudden death immediately after birth. The case is extremely unusual because of the diffuse bilateral involvement. The extensive involvement of both lungs could explain the abrupt onset of the symptoms and the ineffectiveness of resuscitation attempts. The presence of cartilage as a part of the malformation adds interest to the case, since it is seldom found in this malformation and to the best of our knowledge has been reported only exceptionally in a type II CCAM.

Demonstration of apoptosis in human skin injuries as an indicator of vital reaction.

Demonstrating the vital character of an injury and estimation of the age are routine tasks in forensic pathology and although many different techniques have been applied to this problem none have been found to be completely satisfactory. Apoptosis, an active genetically controlled process, is the major mechanism by which homeostasis of a number of physiological systems in the body is regulated and changes in the rate following different kinds of stimuli have prompted us to test it as an indicator of vitality. We used an in situ end-labelling technique (Apop-Tag) in 30 human surgical skin injuries with age since injury ranging from 3 min to 8 h and found that apoptotic keratinocytes are found in over 50% of the cases with a post-infliction interval of at least 120 min. Apoptosis was not seen in injuries less than 120 min old or in normal skin, which was used as an external control. These results suggest that apoptosis could be a useful indicator for the intravital occurrence of injuries and could help to estimate the date of the skin injuries in some cases. The importance of strict technical control is stressed and the necessity of a complementary technique to confirm apoptosis is discussed.

Muerte súbita debida a puente arterial coronario / Unexpected death due to myocardial coronary bridging

Una gran parte de las muertes naturales tienen lugar bajo la forma de una muerte súbita. Este tipo de fallecimientos representan una considerable perturbación económica y emocional para la sociedad y la familia, especialmente cuando afectan a personas jóvenes. En el presente caso se describen las circuns-tancias de la muerte, y los hallazgos macro y microscópicos en un caso de puente coronario intra-miocárdico, presente en un joven de 27 años, que fallece súbitamente mientras realizaba un vigoroso ejercicio físico (cortando árboles). Se practicó una autopsia médicolegal completa, encontrándose como hallazgo principal un puente arterial coronario. Se describen las circunstancias de la muerte, los hallazgos macro y microscópicos, incluyendo la inmunohistoquímica. Se discute la localización y el significado fisiopatológico de este hallazgo (AU)