OBJECTIVES: To investigate the concentration and change characteristics of 1, 5-anhydroglucitol (1, 5-AG) in the vitreous humor of rabbit cadavers with hyperglycemic metabolism, and to explore the value of 1, 5-AG in forensic pathology identification of death caused by hyperglycemic metabolism disorders. METHODS: A diabetic hyperglycemic rabbit model was established by using alloxan. Eighteen rabbits with fasting glucose concentration ≥13.80 mmol/L (experimental group) and 18 healthy rabbits with fasting glucose concentration ≤6.10 mmol/L (control group) were selected. After death from air embolism. The blood samples were collected immediately, and vitreous humor samples were collected at 0 h, 12 h, 24 h and 36 h after death. The concentration of 1, 5-AG in the blood and vitreous humor of rabbits was determined. RESULTS: The blood glucose concentration in the experimental group was (25.10±3.14) mmol/L. At the time of death, there was no significant difference in the concentration of 1, 5-AG in the blood [(0.94±0.20) μg/mL] and in the vitreous humor (0.99±0.05 μg/mL, P>0.05). The concentration of 1, 5-AG in the vitreous humor of the experimental group was lower than that of the corresponding control group at all time points (P<0.05), and there was no significant difference betwwen 1, 5-AG concentration in vitreous humor between earch time point in the experimental group and the control group (P>0.05). Correlation analysis showed that the concentration of 1,5-AG in blood was negatively correlated with blood glucose in both control group and experimental group (control group: r=-0.79, P<0.05; experimental group: r=-0.97, P<0.05). CONCLUSIONS Vitreous humor can replace blood as an effective test sample for 1,5-AG detection. The concentration of 1, 5-AG in rabbit vitreous humor remains stable within 36 hours after death and is not affected by the change of postmortem interval. If the concentration of 1, 5-AG decreases significantly, it indicates the existence of hyperglycemia in rabbits before death.
Animals ; Rabbits ; Blood Glucose/metabolism* ; Postmortem Changes ; Vitreous Body/metabolism* ; Cadaver ; Autopsy

OBJECTIVES: The metabolomics technique of LC-MS/MS combined with data analysis was used to detect changes and differences in metabolic profiles in the vitreous humor of early rat carcasses found in water, and to explore the feasibility of its use for early postmortem submersion interval (PMSI) estimation and the cause of death determination. METHODS: The experimental model was established in natural lake water with 100 SD rats were randomly divided into a drowning group (n=50) and a postmortem (CO₂ suffocation) immediately submersion group (n=50). Vitreous humor was extracted from 10 rats in each group at 0, 6, 12, 18 and 24 h postmortem for metabolomics analyses, of which 8 were used as the training set to build the model, and 2 were used as test set. PCA and PLS multivariate statistical analysis were performed to explore the differences in metabolic profiles among PMSI and causes of death in the training set samples. Then random forest (RF) algorithm was used to screen several biomarkers to establish a model. RESULTS: PCA and PLS analysis showed that the metabolic profiles had time regularity, but no differences were found among different causes of death. Thirteen small molecule biomarkers with good temporal correlation were selected by RF algorithm. A simple PMSI estimation model was constructed based on this indicator set, and the data of the test samples showed the mean absolute error (MAE) of the model was 0.847 h. CONCLUSIONS The 13 metabolic markers screened in the vitreous humor of rat corpses in water had good correlations with the early PMSI. The simplified PMSI estimation model constructed by RF can be used to estimate the PMSI. Additionally, the metabolic profiles of vitreous humor cannot be used for early identification of cause of death in water carcasses.
Animals ; Biomarkers/metabolism* ; Cadaver ; Chromatography, Liquid ; Immersion ; Postmortem Changes ; Rats ; Rats, Sprague-Dawley ; Tandem Mass Spectrometry ; Vitreous Body/metabolism* ; Water/metabolism*

BACKGROUNDManganese-enhanced magnetic resonance imaging (MEMRI) for visual pathway imaging via topical administration requires further research. This study investigated the permeability of the corneal epithelium and corneal toxicity after topical administration of Mn2+ to understand the applicability of MEMRI.

METHODSForty New Zealand rabbits were divided into 0.05 mol/L, 0.10 mol/L, and 0.20 mol/L groups as well as a control group (n = 10 in each group). Each group was further subdivided into epithelium-removed and epithelium-intact subgroups (n = 5 in each subgroup). Rabbits were given 8 drops of MnCl2in 5 min intervals. The Mn2+ concentrations in the aqueous and vitreous humors were analyzed using inductively coupled plasma-mass spectrometry at different time points. MEMRI scanning was carried out to image the visual pathway after 24 h. The corneal toxicity of Mn2+ was evaluated with corneal imaging and pathology slices.

RESULTSBetween the aqueous and vitreous humors, there was a 10 h lag for the peak Mn2+ concentration times. The intraocular Mn2+ concentration increased with the concentration gradients of Mn2+ and was higher in the epithelium-removed subgroup than that in the epithelium-intact subgroup. The enhancement of the visual pathway was achieved in the 0.10 mol/L and 0.20 mol/L epithelium-removed subgroups. The corresponding peak concentrations of Mn2+ were 5087 ± 666 ng/ml, 22920 ± 1188 ng/ml in the aqueous humor and 884 ± 78 ng/ml, 2556 ± 492 ng/ml in the vitreous body, respectively. Corneal injury was evident in the epithelium-removed and 0.20 mol/L epithelium-intact subgroups.

CONCLUSIONSThe corneal epithelium is a barrier to Mn2+, and the iris and lens septum might be another intraocular barrier to the permeation of Mn2+. An elevated Mn2+ concentration contributes to the increased permeation of Mn2+, higher MEMRI signal, and corneal toxicity. The enhancement of the visual pathway requires an effective Mn2+ concentration in the vitreous body.

Administration, Topical ; Animals ; Aqueous Humor ; drug effects ; metabolism ; Cornea ; drug effects ; metabolism ; Epithelium, Corneal ; drug effects ; metabolism ; Magnetic Resonance Imaging ; methods ; Male ; Manganese ; administration & dosage ; pharmacokinetics ; pharmacology ; Rabbits ; Visual Pathways ; drug effects ; Vitreous Body ; drug effects ; metabolism

BACKGROUNDThis study was to examine the expression of total vascular endothelial growth factor (VEGF) and the anti-angiogenic VEGF 165 b isoform in the vitreous body of retinopathy of prematurity (ROP) patients, and to further study the role of the VEGF splicing in the development of ROP.

METHODSThis was a prospective clinical laboratory investigation study. All patients enrolled received standard ophthalmic examination with stage 4 ROP that required vitrectomy to collect the vitreous samples. The control samples were from congenital cataract patients. The expression of total VEGF and the anti-angiogenic VEGF 165 b were measured by enzyme-linked immunosorbent assay. Results were analyzed statistically using nonparametric tests.

RESULTSThe total VEGF level was markedly elevated in ROP samples while VEGF 165 b was markedly decreased compared to control group. The relative protein expression level of VEGF 165 b isoform was significantly decreased in ROP patients which were correlated with the ischemia-induced neovascularization.

CONCLUSIONSThere was a switch of VEGF splicing from anti-angiogenic to pro-angiogenic family in ROP patients. A specific inhibitor that more selectively targets VEGF 165 and controls the VEGF splicing between pro- and anti-angiogenic families might be a more effective therapy for ROP.

Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Infant, Newborn ; Infant, Premature ; Male ; Prospective Studies ; Protein Isoforms ; metabolism ; Retinopathy of Prematurity ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism ; Vitreous Body ; metabolism

PURPOSE: Ischemia-reperfusion injury (I/R injury) is known not only to induce hypoxic and oxidative stress, but also to cause retinal degeneration in rats. Crystallins, known to inhibit the formation of reactive oxygen species, reduce apoptotic cell death. Our goal was to clarify not only the role of I/R injury-mediated crystallins, but also to evaluate the correlation of these compounds to anti-inflammation in the vitreous body. METHODS: Twenty-four Sprague-Dawley rats were used in this study. We induced I/R injury by clamping the optic nerve for 30 minutes and then releasing it. The vitreous bodies were obtained from the experimental and control subjects 24, 48, and 72 hours after I/R injury. Two-dimensional electrophoresis was performed, and the targeted spots were further investigated using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry, spectrophotometry, Western blotting, and histological examination. RESULTS: After I/R injury, 23 spots were identified as crystallins. The betaB2 crystallins were transcriptionally and post-translationally regulated, whereas the alphaB crystallins were controlled by post-translational modifications in the vitreous bodies of the rats. The total amounts of alphaA and beta crystallins (including isotypes of beta crystalline) had increased 48 hours after injury. The phosphorylation of alphaB crystallin (at serine residues 19, 45, and 59) was significantly increased 48 hours later, whereas phosphorylation of ERK1/2 showed the greatest decrease. CONCLUSIONS: During hypoxic and oxidation stress, our results suggest that phosphorylated alphaB crystalline inhibits RAS, resulting in the inactivation of ERK1/2. The phosphorylation of alphaB crystallin may be associated with the inflammatory suppression in the vitreous body via the I/R injury model system.
Animals ; Blotting, Western ; Oxidative Stress ; Phosphorylation ; Protein Processing, Post-Translational ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury/*metabolism/pathology ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Vitreous Body/*metabolism/pathology ; beta-Crystallins/*metabolism

OBJECTIVE: To investigate the mechanism of myopia following intravitreous injection of MK801 (dizocipine maleate) intravitreous injected. METHODS: Three-week-old guinea pigs were divided into six groups: group A (control), group B (3 weeks form-deprivation in right eye), group C ( 3 weeks form-deprivation in right eye + saline), group D (3 weeks form-deprivation in right eye + MK801 1ng), group E (3 weeks form-deprivation in right eye + MK801 10 ng), group F (3 weeks form-deprivation in right eye + MK801 100 ng). The refraction and axial length of the eyes were measured. ncNOS was measured by hybridization in situ, and cyclic GMP (cGMP) concentrations by radioimmunochemistry. The correlation between MK801 concentration and diopter degree, axial length of the eyes, and levels of ncNOS or cyclic GMP were analyzed with linear correlation in the groups C-F. RESULTS: Diopter degree was decreased, axial eye length was shorted and levels of ncNOS and c-GMP were decreased in groups C, D, E and F dependent on the concentration of MK801. The diopter degree had positive correlation with MK801 concentration (r=0.702, P<0.05), while the axial eye length and the levels of ncNOS and cGMP were negatively correlated (r=-0.736, -0.637, -0.725, P<0.05) CONCLUSION MK801 injected into the vitreous humor can restrain myopia by down-regulated the expression of the nitric oxide-cyclic GMP signaling pathway. The effect is concentration dependent.
Animals ; Cyclic GMP ; metabolism ; Dizocilpine Maleate ; administration & dosage ; pharmacology ; Down-Regulation ; Female ; Form Perception ; physiology ; Guinea Pigs ; Injections, Intraocular ; Male ; Myopia ; physiopathology ; Nitric Oxide Synthase Type I ; metabolism ; Sensory Deprivation ; physiology ; Signal Transduction ; drug effects ; Vitreous Body ; drug effects

Accurate estimation of the postmortem interval (PMI) has been one of the most important and complicated issues in the forensic practice. In order to provide novel perspectives for the future research concerning PMI, the advantages and disadvantages of related traditional methods, postmortem degradation of nucleic acid and tissue, the componential change of vitreous humor and histological biochemistry since 2002 have been introduced and compared in this review.
Animals ; Autopsy ; Body Temperature ; DNA/metabolism* ; Forensic Medicine/methods* ; Humans ; Muscle, Skeletal/pathology* ; Nucleic Acids/metabolism* ; Postmortem Changes ; Potassium/metabolism* ; RNA, Messenger/metabolism* ; Regression Analysis ; Time Factors ; Vitreous Body/metabolism*

BACKGROUNDNeovascularization can cause vision loss in proliferative diabetic retinopathy (PDR) and may be affected by many factors. Stromal cell-derived factor-1 (SDF-1) is a potent stimulator of angiogenesis. The study was aimed to investigate the expression of SDF-1 and its correlation with vascular endothelial growth factor (VEGF) in the eyes with diabetic retinopathy.

METHODSThe levels of SDF-1 and VEGF were measured by enzyme-linked immunosorbent assay in the vitreous of 41 eyes of 41 patients with PDR and 12 eyes of 12 patients with idiopathic macular hole (IMH). Vitreous fluid samples and fibrovascular preretinal membranes were obtained at vitrectomy. SDF-1 and VEGF were localized using immunohistochemistry.

RESULTSThe vitreous concentration of VEGF was significantly higher in eyes with PDR ((2143.7 +/- 1685.21) pg/ml) than in eyes with IMH ((142.42 +/- 72.83) pg/ml, P < 0.001). The vitreous level of SDF-1 was also significantly higher in eyes with PDR ((306.37 +/- 134.25) pg/ml) than in eyes with IMH ((86.91 +/- 55.05) pg/ml, P < 0.001). The concentrations of both VEGF and SDF-1 were higher in eyes with active PDR than in eyes with inactive PDR. Panretinal photocoagulation (PRP) could decrease the SDF-1 levels in the vitreous of PDR patients. The vitreous concentration of SDF-1 correlated with that of VEGF in eyes with PDR (r = 0.61, P < 0.001). The costaining of SDF-1 and VEGF was confined to the vascular components in preretinal membranes.

CONCLUSIONSSDF-1 protein is highly expressed in both the vitreous and preretinal membranes of PDR patients; SDF-1 may be correlated with VEGF in angiogenesis in PDR.

Chemokine CXCL12 ; metabolism ; Diabetic Retinopathy ; metabolism ; pathology ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunohistochemistry ; Neovascularization, Pathologic ; metabolism ; physiopathology ; Retinal Perforations ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism ; Vitrectomy ; Vitreous Body ; metabolism

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*

OBJECTIVETo investigate in vivo survival of retinal ganglion cells (RGCs) after partial blockage of optic nerve (ON) axoplasmic flow by sub-retinal space or vitreous cavity injection of brain-derived neural factor (BDNF) produced by genetically modified neural progenitor cells (NPCs).

METHODSAdult Sprague-Dawley (SD) rat RGCs were labeled with granular blue (GB) applied to their main targets in the brain. Seven days later, the left ON was intra-obitally crushed with a 40 g power forceps to partially block ON axoplasmic flow. Animals were randomized to three groups. The left eye of each rat received a sham injection, NPCs injection or an injection of genetically modified neural progenitors producing BDNF (BDNF-NPCs). Seven, 15 and 30 days after ON crush, retinas were examined under a fluorescence microscope. By calculating and comparing the average RGCs densities and RGC apoptosis density, RGC survival was estimated and the neuro-protective effect of transplanted cells was evaluated.

RESULTSSeven, 15 and 30 days after crush, in the intra-vitreous injection group, mean RGC densities had decreased to 1885 +/- 68, 1562 +/- 20, 1380 +/- 7 and 1837 +/- 46, 1561 +/- 58, 1370 +/- 16, respectively with sham injection or neural progenitors injection. However, RGCs density in the groups treated with intra-vitreous injection of BDNF-NPC was 2101 +/- 15, 1809 +/- 19 and 1625 +/- 34. Similar results were found in groups after sub-retinal injection. Higher densities were observed in groups treated with BDNF-NPCs. There were statistically significant differences among groups through nonparametric tests followed by the Mann-Whitely test. RGC apoptosis density in BDNF-NPC at each follow-up time was less than in other groups.

CONCLUSIONSA continuous supply of neurotrophic factors by the injection of genetically modified neural progenitors presents a highly effective approach to counteract optic neuropathy and RGC degeneration after partial ON axoplasmic flow blockage.

Animals ; Apoptosis ; Axonal Transport ; Brain-Derived Neurotrophic Factor ; genetics ; Cell Survival ; Gene Transfer Techniques ; Genetic Therapy ; Glaucoma ; therapy ; Male ; Rats ; Rats, Sprague-Dawley ; Retinal Ganglion Cells ; cytology ; Stem Cells ; physiology ; Vitreous Body ; metabolism