OBJECTIVE: To seek a exact method of estimating postmortem interval (PMI). METHODS: This study detected the concentration of magnesium (Mg) and iron (Fe) in vitreous humor of rabbit at 96 h after death and explored the relationship between their concentration and PMI using a method ICP-MS. RESULTS: The concentra-tion of Mg in vitreous humor of rabbit at 48 h after death and Fe in vitreous humor of rabbit at 6-48 h after death were related to PMI significantly. The formulae of the relationship between PMI and Mg concentrations is y = 0.0738x2 + 0.6997x + 11.45 (within 48 h, R2 = 0.9119). The formulae of the relationship between PMI and Fe concentrations is y = 0.0411x2 - 0.3148x + 1.4113 (within 6-48 h, R2 = 0.9594). CONCLUSION The concentration of Mg in vitreous humor of rabbit at 48 h after death and Fe in vitreous humor of rabbit at 6-48 h after death may be as reference indicator to estimate PMI.
Animals ; Iron/analysis* ; Magnesium/analysis* ; Mass Spectrometry/methods* ; Postmortem Changes ; Rabbits ; Time Factors ; Vitreous Body/chemistry*

Postmortem chemistry is becoming more and more essential in routine forensic pathology and has made considerable progress over the past years. Biochemical analyses of vitreous humor, blood, urine and cerebrospinal fluid may provide important information in determining the cause of death or in elucidating forensic issues. Postmortem chemistry may be essential for the determination of cause of death when morphological methods (diabetes mellitus, alcoholic ketoacidosis and electrolytic disorders) cannot detect the pathophysiological changes involved in the death process. It can also provide many information in other forensic situations, including myocardial ischemia, sepsis, inflammation, infection, anaphylaxis and hormonal disturbances. The most recent relevant research advances on glucose metabolism, liver function, cardiac function, renal function, sepsis, inflammation, infection, anaphylaxis and hormonal aspect are hereby reviewed.
Anaphylaxis ; Autopsy/trends* ; Biomarkers/analysis* ; Body Fluids/chemistry* ; Death ; Diabetes Mellitus ; Forensic Pathology/methods* ; Humans ; Postmortem Changes ; Sepsis ; Vitreous Body

OBJECTIVETo prepare ligustrazine (TMPZ) ocular sustained-release implant, and investigate its in vitro drug release, pharmacokinetics in rabbit vitreum and in vitro correlation.

METHODLigustrazine ocular sustained-release implants were prepared by micro-twin conical screw mixers with hot-melting extrusion method, with polyactic-co-glycolic acid (PLGA) as the matrix. HPLC was adopted to determine the concentration in vitreum after ligustrazine was implanted in rabbit eyes, in order to examine its in vivo sustained-release behavior, and study the correlation between in vitro and in vivo.

RESULTLigustrazine implants were prepared with a drug-loading rate between 10% and 30%, which was in conformity to the pharmacopoeia in terms of the content uniformity. Its in vitro release was in conformity to the zero-order release model. With PLGA 5050, 2. 5A as a vector, ligustrazine implants with a drug-loading rate of 30% could slowly release drug for more than 3 weeks, indicating a good correlation between in vitro and in vivo release.

CONCLUSIONLigustrazine ocular implants prepared with hot-melting extrusion method is practicable. Ligustrazine ocular implants release drug smoothly in rabbit vitreous vitreums, suggesting good sustained-release effect.

Animals ; Biological Availability ; Drug Implants ; Eye ; Female ; Male ; Polyglycolic Acid ; chemistry ; Pyrazines ; administration & dosage ; chemistry ; pharmacokinetics ; Rabbits ; Vitreous Body

The blood alcohol concentration (BAC) is an important evidence to determine the alcohol level at the time of death. But due to the postmortem synthesis and diffusion of alcohol, the cadaveric BAC can not always represent the original BAC at the time of death. It is a crucial problem to determine the original level in corpse. The article reviewed the following points: the distribution in corpse, and how to sample, the influences on the diffusion of alcohol and putrefaction, the discussion about alcohol mass concentration measure methods.
Body Fluids/chemistry* ; Cadaver ; Ethanol/urine* ; Forensic Medicine/methods* ; Gastrointestinal Contents/chemistry* ; Humans ; Myocardium/metabolism* ; Postmortem Changes ; Time Factors ; Vitreous Body/chemistry* ; Wounds and Injuries/metabolism*

OBJECTIVE: To seek a precise method for estimating postmortem interval (PMI) in forensic medicine practice. METHODS: This study detected the concentration of 21 elements in the vitreous humor of rabbit within 96 hours after death and explored the relationship between their concentration and PMI using the method of ICP-MS. RESULT: It was shown that the concentration of 9 elements in vitreous humor of rabbit within different intervals after death were correlated to PMI available as a reference indicator to estimate PMI. CONCLUSION The changes in the concentration of certain elements in vitreous humor of vitreous humor are correlated with PMI and determination of such changes can be used to estimate the time of death.
Animals ; Calcium/analysis* ; Forensic Medicine ; Iron/analysis* ; Magnesium/analysis* ; Postmortem Changes ; Potassium/analysis* ; Rabbits ; Time Factors ; Vitreous Body/chemistry*

Estimation of postmortem interval (PMI) is one of the problems that need to be solved for forensic examination of the dead body. Accurate estimation of PMI has great values to criminal investigation and trial. The levels of chemical components in human vitreous humor are changed with time after death, which can help estimate the PMI. The levels of certain chemical components, such as potassium, magnesium, ammonia, urea, creatinine, uric acid, hypoxanthine, lactic acid and so on, in human vitreous humor will gradually increase with time after death, while others such as calcium, sodium, enzymes, glucose, vitamin C and so on will decrease. The updates and advances in those studies were reviewed in this article.
Calcium/analysis* ; Forensic Pathology ; Humans ; Magnesium/analysis* ; Postmortem Changes ; Potassium/analysis* ; Sodium/analysis* ; Time Factors ; Vitreous Body/chemistry*

OBJECTIVE: To seek a exact method of estimating postmortem interval (PMI). METHODS: This study detected the concentration of zincum(Zn) and nickel(Ni) in vitreous humor of rabbit at hour 96 after death and explored the relationship between their concentration and PMI using a method ICP-MS. RESULTS: The concentration of Zn and Ni in vitreous humor of rabbit at hour 24 after death were related to PMI significantly; The formulae of the relationship between PMI and Zn concentrations is y = 0.1404x2 - 1.3351x + 3.8298 (within 24 h; R2 = 0.9202). The formula of the relationship between PMI and Ni concentrations is y = 0.0043x2 - 0.0596x + 0.2665(within 24 h; R2 = 0.9103). CONCLUSION The concentration of Zn and Ni in vitreous humor of rabbit may be a reference indicator to estimate early PMI.
Animals ; Female ; Forensic Medicine ; Male ; Nickel/analysis* ; Postmortem Changes ; Rabbits ; Time Factors ; Vitreous Body/chemistry* ; Zinc/analysis*

Dexamethasone sodium phosphate (DSP) is increasingly used in the treatment of ocular inflammatory diseases by systemic, periocular, and recently, intravitreal injection. We have developed a method for the determination of vitreous levels of DSP by reverse phase HPLC. In this method, co-elution of vitreous proteins with DSP is resolved by a prior sample clean-up procedure using Waters Sep-Pak C18 cartridge; the protein is separated and eluted with water while DSP, paraben and prednisone are eluted with methanol. DSP in the resulting sample is then separated by reverse phase HPLC and quantified by UV absorption at 254 nm. The recovery of DSP through the sample clean-up is 68.9 +/- 3.0%. DSP quantitation is linear from 0.1 mg to 1.0 mg per 1.0 ml vitreous. This method provides a simple, sensitive and reliable technique for determining the vitreous levels of DSP.
Animals ; Anti-Inflammatory Agents/*analysis ; Chromatography, High Pressure Liquid/*methods ; Dexamethasone/*analogs & derivatives/analysis ; Rabbits ; Reproducibility of Results ; Sensitivity and Specificity ; Vitreous Body/*chemistry

OBJECTIVE: To investigate concentration changes of amylase in rabbits vitreous humor of acute pancreatitis associated with postmortem different interval. METHODS: To induce animal model of acute pancreatitis with sodium taurocholate, observed concentration changes of amylase after different postmortem interval, then compared with normal. RESULTS: The concentration of amylase in vitreous humor of rabbit 24h after death were related to postmortem interval significantly; The concluded formulae of the relationship between postmortem interval and amylase concentration is y=8.7420+0.7699x-0.0083x2 (R2=92.62792, F=14.89734, P=0.001). CONCLUSION Concentration changes of amylase in vitreous humor of acute pancreatitis associated with postmortem interval may provide a new sensitive and objective method for the forensic early injury time estimation.
Amylases/analysis* ; Animals ; Disease Models, Animal ; Female ; Male ; Pancreatitis/enzymology* ; Postmortem Changes ; Rabbits ; Spectrophotometry/methods* ; Taurocholic Acid ; Time Factors ; Vitreous Body/chemistry*

OBJECTIVE: To investigate the relationship between postmortem interval (PMI) and concentration changes of components in swine vitreous humor. METHODS: Ninety-six porcine eyes from swine dying from acute massive hemorrhage, being randomly divided into 24 groups, were stored in dark situation, at temperature of (15 +/- 2) degrees C and humidity of (50 +/- 5)% for 2-96 hours separately. The vitreous humor was collected. Concentrations of K+, Na+, Cl- and hypoxanthine (Hx) were analyzed by automatic biochemical analyzer and ultra performance liquid chromatograph (UPLC). The data were statistically analyzed by SPSS software. RESULTS: Linear regression analysis showed that concentrations of vitreous K+ and Hx were positively correlated with PMI(R2=0.767 and R2 = 0.793, respectively). Binary linear regression showed a higher correlation for K+ and Hx with PMI estimation (R2 = 0.866). PMI was not significantly correlated with vitreous Na+ and Cl- concentrations. CONCLUSION Vitreous K+ and Hx concentrations can be used as the objective markers for PMI estimation. The binary linear regression functions of vitreous K+ and Hx concentrations with PMI are more accurate for estimating the PMI.
Animals ; Chromatography, High Pressure Liquid/methods* ; Female ; Forensic Pathology ; Hypoxanthine/analysis* ; Male ; Postmortem Changes ; Potassium/analysis* ; Regression Analysis ; Sodium/analysis* ; Swine ; Temperature ; Time Factors ; Vitreous Body/chemistry*