Vitreous humour as a complementary sample to blood for the detection/confirmation of diazepam: ante-mortem and post-mortem studies in an animal model

2004 ◽  
Vol 23 (12) ◽  
pp. 571-577 ◽  
Author(s):  
H M Teixeira ◽  
F Reis ◽  
P Proença ◽  
P Ramos ◽  
O Quińtela ◽  
...  
Keyword(s):  
Drug Administration ◽  
Plasma Concentrations ◽  
Forensic Toxicology ◽  
Vitreous Humour ◽  
Toxic Substances ◽  
Time Of Death ◽  
Post Mortem ◽  
Correlation Ratio ◽  
Animal Group ◽  
Toxic Dose

The quantification of medical or toxic substances in vitreous humour (VH) could be very useful in forensic toxicology when blood sample determinations are impossible due to absence or deterioration. However, few studies have been made in this area and even fewer have tried to find a relationship between drug levels in both samples. To determine a correlation ratio between blood and VH diazepam (DZ) levels, we performed an experimental study using rabbits administered with a sub-toxic dose of DZ under known and controlled conditions. Blood and VH samples were collected 0.5, 1, 2, 3 and 6 hours after the drug administration in order to determine DZ and its main active metabolite, desmethyldiazepam (DMD). In addition, we have studied an animal group sacrificed 2 hours after intramuscular (i.m.) drug administration with blood and VH collection 24 hours later, to evaluate the existence of possible post-mortem changes. After DZ administration, a fast absorption phase was observed with a plasma Cmax value 1 hour after, followed by a rapid concentration decrease, with a half-life of 1 hour, indicating that, besides elimination, a fast distribution to other organs and tissues and/or hepatic metabolism occurred. Diazepam Cmax value in VH was achieved between 1 and 2 hours, when plasma concentrations had already decreased to half the value. The plasma/VH DZ ratio calculated at this time was 10. In the post-mortem study, while plasma DZ concentration at 24 hours was smaller, DMD levels were higher than those at the time of death. In the VH, both DZ and DMD concentrations at 24 hours were higher than those obtained at the time of death. That is, in both fluids DZ and DMD concentrations were different from those at the time of death and post-mortem distribution and redistribution phenomena occurred. The combination of antemortem and post-mortem studies has allowed the determination of a correlation ratio for DZ in the rabbit of 6×, comparing the concentrations in VH collected 24 hours after death with the concentrations detected in plasma at the time of death. This study opens new perspectives for the use of VH as a complementary sample to blood for DZ detection and confirmation. The putative relevance of the correlation ratio obtained, for forensic toxicology practice with medical substances, namely benzodiazepines, recommends further studies in humans.

scholarly journals The post mortem diagnosis of fatal hypoglycaemia using the fatty liver and kidney syndrome of chicks as a model

1982 ◽  
Vol 47 (2) ◽  
pp. 235-241 ◽  
Author(s):  
D. W. Bannister ◽  
Iris E. O'Neill ◽  
C. C. Whitehead
Keyword(s):  
Fatty Liver ◽  
Plasma Glucose ◽  
Vitreous Humour ◽  
Hepatic Glycogen ◽  
Time Of Death ◽  
Post Mortem ◽  
Liver And Kidney

1. The concentrations of vitreous humour and plasma glucose were closely correlated in both healthy and fatty liver and kidney syndrome-affected chicks at time of death.2. The values of vitreous humour glucose and lactate decreased rapidly after death, such that they were not reliable indicators of the presence of hypoglycaemia immediately ante mortem.3. Hepatic glycogen was extremely low in fatty liver and kidney syndrome-affected birds, whereas significant quantities remained in healthy birds up to at least 24 hpost mortem.

The Effect of the Post-Mortem Interval on the Level of Creatine in Vitreous Humour

1989 ◽  
Vol 29 (1) ◽  
pp. 47-54 ◽  
Author(s):  
M. Piette
Keyword(s):  
Confidence Interval ◽  
Vitreous Humour ◽  
Time Of Death ◽  
Post Mortem ◽  
Legal Practice ◽  
Post Mortem Interval ◽  
Satisfactory Correlation

By means of 103 medico-legal autopsies it was established that a rise in the creatine level occurs in the vitreous humour after death. In view of the satisfactory correlation between the post-mortem interval and the creatine level in the vitreous humour (r = 0.84, p < 0.001) investigations were undertaken as to whether the creatine level in vitreous humour can serve in current medico-legal practice as an indication for the post-mortem interval, especially for the later period (more than three days). On balance this creatine determination is only useful when combined with all other medico-legal parameters that establish the time of death, remembering that the confidence-interval in the investigations was rather wide.

Simultaneous analysis of potassium and ammonium ions in the vitreous humour by capillary electrophoresis and their integrated use to infer the post mortem interval (PMI)

2020 ◽  
pp. 002580242093423 ◽  
Author(s):  
Covadonga Palacio ◽  
Rossella Gottardo ◽  
Vito Cirielli ◽  
Giacomo Musile ◽  
Yvane Agard ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Clinical Chemistry ◽  
The Body ◽  
Simultaneous Analysis ◽  
Vitreous Humour ◽  
Ammonium Concentration ◽  
Time Of Death ◽  
Post Mortem ◽  
Ammonium Ions ◽  
Post Mortem Interval

Post-mortem changes of ions in the body fluids have been proposed as an objective tool for inferring the time of death. In particular, the post-mortem increase of potassium concentrations in the vitreous humour has gained great attention in the literature. On the other hand, ammonium, another ion released in post-mortem processes, has received much less attention, potentially due to unresolved analytical issues using current clinical chemistry methods. This paper presents an application of a new analytical approach based on capillary electrophoresis providing the simultaneous analysis of potassium and ammonium ions in the vitreous humour. In addition, to assess the consistency of the post-mortem increase of ammonium concentrations in the vitreous humour, the determination of this ion in the vitreous humour of the two eyes of the same body at the same post-mortem interval has been verified. Vitreous humour was collected from 33 medico-legal cases where the time of death was known exactly. Prior to analysis, all samples were diluted 1:20 with a 40 μg/mL solution of BaCl2 (internal standard). In the study of the variability of the ammonium concentration between the two eyes, no statistically significant differences were found, supporting the hypothesis of an even post-mortem increase of the ion concentrations in this particular biological fluid. Significant correlations of potassium and ammonium ions with the post-mortem interval were found, with r2 of 0.75 and 0.70, respectively.

Levels of Potassium in the Vitreous Humour after Death

1965 ◽  
Vol 5 (3) ◽  
pp. 150-156 ◽  
Author(s):  
Wilhelmina M. H. Hughes
Keyword(s):  
Potassium Level ◽  
Accurate Method ◽  
Vitreous Humour ◽  
Time Of Death ◽  
Post Mortem ◽  
Post Mortem Interval

Levels of vitreous potassium were studied in 135 routine post-mortem cases. A rise in the potassium level was found but it could not be correlated with sufficient consistency with the post-mortem interval to make this an accurate method of estimating the time of death.

RIGOR MORTIS: PHYSIOLOGY

2021 ◽  
Vol 6 ◽  
Author(s):  
Heron Teixeira
Keyword(s):  
Body Weight ◽  
Causes Of Death ◽  
Natural Course ◽  
Important Task ◽  
Time Of Death ◽  
Post Mortem ◽  
Rigor Mortis ◽  
Intrinsic Factors ◽  
The Subject ◽  
Extrinsic And Intrinsic Factors

Introduction: Estimating the time of death is an important task in day-to-day forensic work and many factors for its designation are understood, one of which is rigor mortis. They can be altered by extrinsic and intrinsic factors, such as temperature location, humidity, heat, age, sex, length and body weight, and can be used as a parameter for approximate identification of the time of death. Objective: To carry out a brief review on the topic in order to promote a better understanding of the subject addressed and fully understand its physiology. Materials and Methods: Pubmed, Scielo and Medline databases were searched without date restrictions for articles published in English and Portuguese using the descriptors rigor mortis, autolysis and changes after death. Results: The theme presents consolidated researches regarding its natural course, being an important tool to estimate the time of death along other signs that appear after death, as well as to estimate some causes of death. Conclusion: Understanding the development of rigor mortis, helps to identify and distinguish processes that may have led to death and the post-mortem time.

scholarly journals The Toxin of the Bacillus Enteritidis of Gärtner

1906 ◽  
Vol 6 (2) ◽  
pp. 112-122 ◽  
Author(s):  
E. P. Cathcart
Keyword(s):  
Normal Saline ◽  
Clinical Symptoms ◽  
Considerable Extent ◽  
Distilled Water ◽  
Toxic Substances ◽  
Post Mortem ◽  
Fluid Medium ◽  
Heat Resistant ◽  
Feeding Experiments ◽  
Infected Meat

1. Cultures of Gärtner's bacillus grown on broth do not excrete any large amount of toxin into the fluid medium.2. Suspension in broth made from ordinary agar cultures and killed by means of heat (30 mins. at 60°C.) are fairly toxic.3. The most toxic preparations were obtained by autolysis of the bacilli, especially in the presence of toluol.4. Cultures grown on agar and killed by means of chloroform vapour lose their toxicity to a considerable extent.5. Autolysis takes place best in the presence of distilled water or of normal saline.6. Autolysed material sterilised by heat is more toxic than the filtrate obtained from the same digest.7. Shaking the bottles during the process of autolysis increases the yield of toxic substances.8. Gärtner toxin withstands heating to 100°C. for 30 mins.9. Paratyphoid B. bacillus cultures on autolysis yield a filtrate quite as toxic as those from the Gärtner bacillus itself.10. Paratyphoid toxin is also heat resistant (100° for 30 mins.).11. A colon bacillus gave a toxin which was fatal to mice. It was not heat resistant.12. Feeding experiments with Gärtner-infected meat, both cooked and uncooked, proved successful.13. So far as the present experiments go the connection between virulence and toxicity does not appear to be very definite.14. The Gärtner bacillus contains a toxin of the endotoxin type as is shown in comparing results 1 and 3. This toxin gives rise to very definite clinical symptoms of which the gluing together of the eyelids and the prolonged narcosis before death are the most notable. The post-mortem signs have much in common with those arising from other intestinal intoxications.

Use of post mortem vitreous humour electrolytes in diagnosing salt water drowning deaths

Pathology ◽  
2018 ◽  
Vol 50 ◽  
pp. S97
Author(s):  
Jack Garland ◽  
Rexson Tse ◽  
S. Anne ◽  
C. Oldmeadow ◽  
J. Attia ◽  
...  
Keyword(s):  
Salt Water ◽  
Vitreous Humour ◽  
Post Mortem

A Review of the Literature as to the Present Possibilities and Limitations in Estimating the Time of Death

1976 ◽  
Vol 16 (4) ◽  
pp. 269-276 ◽  
Author(s):  
R. Van Den Oever
Keyword(s):  
Forensic Medicine ◽  
Large Error ◽  
Time Of Death ◽  
Post Mortem ◽  
Review Of The Literature ◽  
Biochemical Tests ◽  
Post Mortem Interval ◽  
Suitable Combination ◽  
Exact Moment ◽  
The Individual

Determining the exact moment of death in medicolegal cases is not possible since post-mortem changes of the human body are variable and often misjudged. The most reliable physical and biochemical methods of estimating the post-mortem interval are reviewed and the author tries to find out why, in spite of all the previous studies, which have often given good results, the individual methods are neither popular nor practical in routine forensic medicine cases. For greater accuracy in estimating the time of death further investigation should be carried out to find a suitable combination of some physical and biochemical tests complementary to the data produced by each method and preventing the rather large error range of each individual test.

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