Estimating trace deposition time with circadian biomarkers: a prospective and versatile tool for crime scene reconstruction

Linking biological samples found at a crime scene with the actual crime event represents the most important aspect of forensic investigation, together with the identification of the sample donor. While DNA profiling is well established for donor identification, no reliable methods exist for timing forensic samples. Here, we provide for the first time a biochemical approach for determining deposition time of human traces. Using commercial enzyme-linked immunosorbent assays we showed that the characteristic 24-h profiles of two circadian hormones, melatonin (concentration peak at late night) and cortisol (peak in the morning) can be reproduced from small samples of whole blood and saliva. We further demonstrated by analyzing small stains dried and stored up to 4 weeks the in vitro stability of melatonin, whereas for cortisol a statistically significant decay with storage time was observed, although the hormone was still reliably detectable in 4-week-old samples. Finally, we showed that the total protein concentration, also assessed using a commercial assay, can be used for normalization of hormone signals in blood, but less so in saliva. Our data thus demonstrate that estimating normalized concentrations of melatonin and cortisol represents a prospective approach for determining deposition time of biological trace samples, at least from blood, with promising expectations for forensic applications. In the broader context, our study opens up a new field of circadian biomarkers for deposition timing of forensic traces; future studies using other circadian biomarkers may reveal if the time range offered by the two hormones studied here can be specified more exactly

Comparison of the effects of acute fluvoxamine and desipramine administration on melatonin and cortisol production in humans.

1. Acute administration of the specific serotonin uptake inhibitor, fluvoxamine (100 mg at 16.00 h), markedly increased nocturnal plasma melatonin concentrations, with high levels extending into the morning hours. 2. Acute administration of the noradrenaline uptake inhibitor, desipramine (DMI) (100 mg at 16.00 h), increased evening plasma melatonin concentrations. 3. Both drug treatments increased the duration of melatonin secretion, fluvoxamine significantly delaying the offset time and DMI significantly advancing the onset time. 4. The stimulatory effect of DMI on plasma melatonin was mirrored by increased urinary 6-sulphatoxymelatonin (aMT6s) excretion. 5. On the contrary, there was no correlation between plasma melatonin and urinary aMT6s concentrations following fluvoxamine treatment, suggesting that fluvoxamine may inhibit the metabolism of melatonin. 6. Treatment with DMI increased plasma cortisol concentrations in the evening and early morning, treatment with fluvoxamine increased plasma cortisol at 03.00 h, 10.00 h and 11.00 h. 7. The drug treatments affected different aspects of the nocturnal plasma melatonin profile suggesting that the amplitude of the melatonin rhythm may depend upon serotonin availability and/or melatonin metabolism whilst the onset of melatonin production depends upon noradrenaline availability

Melatonin treatment in individuals with intellectual disability and chronic insomnia: A randomised placebo-controlled study

Item does not contain fulltextBACKGROUND: While several small-number or open-label studies suggest that melatonin improves sleep in individuals with intellectual disabilities (ID) with chronic sleep disturbance, a larger randomized control trial is necessary to validate these promising results. METHODS: The effectiveness of melatonin for the treatment of chronic sleep disturbance was assessed in a randomized double-blind placebo-controlled trial with 51 individuals with ID. All of these individuals presented with chronic ideopatic sleep disturbance for more than 1 year. The study consisted of a 1-week baseline, followed by 4 weeks of treatment. Parents or other caregivers recorded lights off time, sleep onset time, night waking, wake up time and epileptic seizures. Endogenous melatonin cycle was measured in saliva before and after treatment. RESULTS: Compared with placebo, melatonin significantly advanced mean sleep onset time by 34 min, decreased mean sleep latency by 29 min, increased mean total sleep time by 48 min, reduced the mean number of times the person awoke during the night by 0.4, decreased the mean duration of these night waking periods by 17 min and advanced endogenous melatonin onset at night by an average of 2.01 h. Lights off time, sleep offset time and the number of nights per week with night waking did not change. Only few minor or temporary adverse reactions and no changes in seizure frequency were reported. CONCLUSIONS: Melatonin treatment improves some aspects of chronic sleep disturbance in individuals with ID