PM formation of alcohol Flashcards

1
Q

Can decomposing tissue produce EToh

A

Yes
First observed in early 1950s
Ethyl alcohol found as product of putrefaction in several cases
Could not have been from ante-mortem consumption Corry, J
However thought not to exceed 0.05g%

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2
Q

Is Pm etOh identical to bevarge

A

YES

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3
Q

Factors that affect rate of putrefaction

A

Ambient temperature
Humidity
Distribution and type of microorganisms

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4
Q

Microorganism

A

58 species of bacteria
17 species of yeasts
24 species of mold
That can produce ethyl alcohol under a variety of conditions

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5
Q

What is the greattedt microoragsims

A

Originally thought yeast Candida albicans was the primary organism, but the greatest increase observed was the result of Escherichia coli and not yeast

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6
Q

When can bacteria pentreate intestinal wall

A

Distributed through the bloodstream via the hepatic portal vein and intestinal lymph system as long as the
Body temperature exceeds 5 °C

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7
Q

How can microbial contamination be prevented

A

Refrigeration of body within 4 hours of death
Preserve specimens with 1% NaF after autopsy inhibits ethyl alcohol production by most organisms
Except C. albicans

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8
Q

what are some endogenous ethyl alcohol production results of microbial activity on

A

Glucose
Lactate
Glycerol
Amino acids

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9
Q

Will all microorganisms form ethyl alcohol

A

no

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10
Q

What is thje primary source of endogenous EtOH

A

Glucose

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11
Q

What tissue is high in glucose storage and the site of the greatest production

A

Liver
Skeletal muscles
Lungs
Heart

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12
Q

What is considered an ideal specimen for alcohol analysis

A

Vitreous humor

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13
Q

Why is vitreous humor ideal

A

Reflects antemortem ethyl alcohol concentration
Contains no glucose or microorganism
Protected from trauma and putrefaction

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14
Q

WHat is a poor medium for microbial ethyl alcohol

A

Urine except in diabetics

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15
Q

Case studies PM formation

A

12-57% of ethyl alcohol-positive cases was attributed to postmortem synthesis
Majority of cases attributed to postmortem synthesis did not have significant ethyl alcohol concentrations [<0.07 g%]

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16
Q

Cases with endogenous ethyl alcohol
ZUnmwalt

A

Evaluated for the degree of putrefaction
“SMELLBAD”
Skin slippage, mummification, changes in the eyes, marbling, state of rigor mortis [limpness], bloating, purging of fluids [appalling effusions], and discoloration

17
Q

Cases with endogenous ethyl alcohol
Moorgate tube crash

A

London Northern City Line
Train failed to stop at the line’s end
13 hours to remove injured
42 passengers and motormen died
BAC 80 mg/dL [blood collected from kidney]
“Likely motorman was drinking”
However,
No evidence of drinking

18
Q

Ante vs postmortem

A

History and scene, histology, blood/tissue distributn, Evaluation of chromatograpm, evaluation of ETOH metab, other volatile cmpds

19
Q

Histroy and scene evidence

A

DUI and Evidence in car

20
Q

Histology

A

Gross tissue and histologic evidence
Cirrhotic liver

21
Q

Blood/tissue distribution

A

EtOH peak
Acetone peak

22
Q

Evaluation of EtOH metabolites

A

Serotonin metabolites
Other biomarkers

23
Q

Other volatile compounds

A

Other volatile compounds may be formed during the postmortem interval
Acetaldehyde
Acetone
Isopropanol
Butanol (1, 2, and iso-)
Volatile fatty acids
Gamma hydroxybutyric acid (GHB)

24
Q

Serotonin Metabolite

A

Davis et al (1967) reported that the ratio of serotonin metabolites was altered by the ingestion of ethyl alcohol – remaining altered for up to 16 hours after cessation of drinking
5-hydroxyindoleacetic acid [5-HIAA]
5-hydroxytryptophol [5-HTOL]
Normally 5-HIAA is ~100 x greater than 5-HTOL
Helander et al )1992) found that when alcohol is consumed the formation of 5-HTOL is favored
Shifting the 5-HIAA:%-HTOL from 100:1 to 60:40
Evaluation of serotonin metabolites in urine will assist in the determination of whether the alcohol was from antemortem consumption or postmortem formation
Absence of alcohol ingestion
Normal HTOL/HITAA below 15 pmol/nmol [some 10 pmol/nmol]

25
Q

1-propanol

A

Empirical studies have shown that in the absence of antemortem consumption conc of EtOH should be less than 20x that of n(1)-propanol
Liang et al Rat Study – disproved
Concluded < 20 ratio does not allow discrimination between antemortem ingestion and postmortem formation
Threshold conc of 0.104 mg/dL
Sensitivity – 79%
Specificity – 91%
Authors noted PM production w/o signs of decomposition