Investigation the effects of vitreous humor on proliferation and dedifferentiation of differentiated NTERA2 cells / Investigar os efeitos do humor vítreo na proliferação e desdiferenciação de células NTERA2 diferenciadas

Abstract Mammals have a limited capacity to regenerate their tissues and organs. One of the mechanisms associated with natural regeneration is dedifferentiation. Several small molecules such as vitamin C and growth factors could improve reprogramming efficiency. In this study, the NTERA2-D1 (NT2) cells were induced towards differentiation (NT2-RA) with 10-5 M retinoic acid (RA) for three days and then subjected to various amounts of vitreous humor (VH). Results show that the growth rate of these cells was reduced, while this rate was partly restored upon treatment with VH (NT2-RA-VH). Cell cycle analysis with PI method also showed that the numbers of cells at the S phase of the cell cycle in these cells were increased. The levels of SSEA3 and TRA-1-81 antigens in NT2-RA were dropped but they increased in NT2- RA-VH to a level similar to the NT2 cells. The level of SSEA1 had an opposite pattern. Expression of OCT4 gene dropped after RA treatment, but it was recovered in NT2-RA-VH cells. In conclusion, we suggest VH as a potent mixture for improving the cellular reprogramming leading to dedifferentiation.

Resumo Os mamíferos têm uma capacidade limitada de regenerar seus tecidos e órgãos. Um dos mecanismos associados à regeneração natural é a desdiferenciação. Várias moléculas pequenas, como vitamina C e fatores de crescimento, podem melhorar a eficiência da reprogramação. Neste estudo, as células NTERA2-D1 (NT2) foram induzidas à diferenciação (NT2-RA) com ácido retinóico (RA) 10-5 M por três dias e depois submetidas a várias quantidades de humor vítreo (VH). Os resultados mostram que a taxa de crescimento dessas células foi reduzida, enquanto essa taxa foi parcialmente restaurada após o tratamento com VH (NT2-RA-VH). A análise do ciclo celular com o método PI também mostrou que o número de células na fase S do ciclo celular nessas células estava aumentado. Os níveis de antígenos SSEA3 e TRA-1-81 em NT2-RA diminuíram, mas aumentaram em NT2-RA-VH a um nível semelhante ao das células NT2. O nível de SSEA1 teve um padrão oposto. A expressão do gene OCT4 diminuiu após o tratamento com AR, mas foi recuperado em células NT2-RA-VH. Em conclusão, sugerimos o VH como uma mistura potente para melhorar a reprogramação celular levando à desdiferenciação.

Investigation the effects of vitreous humor on proliferation and dedifferentiation of differentiated NTERA2 cells

Abstract Mammals have a limited capacity to regenerate their tissues and organs. One of the mechanisms associated with natural regeneration is dedifferentiation. Several small molecules such as vitamin C and growth factors could improve reprogramming efficiency. In this study, the NTERA2-D1 (NT2) cells were induced towards differentiation (NT2-RA) with 10-5 M retinoic acid (RA) for three days and then subjected to various amounts of vitreous humor (VH). Results show that the growth rate of these cells was reduced, while this rate was partly restored upon treatment with VH (NT2-RA-VH). Cell cycle analysis with PI method also showed that the numbers of cells at the S phase of the cell cycle in these cells were increased. The levels of SSEA3 and TRA-1-81 antigens in NT2-RA were dropped but they increased in NT2- RA-VH to a level similar to the NT2 cells. The level of SSEA1 had an opposite pattern. Expression of OCT4 gene dropped after RA treatment, but it was recovered in NT2-RA-VH cells. In conclusion, we suggest VH as a potent mixture for improving the cellular reprogramming leading to dedifferentiation.

Resumo Os mamíferos têm uma capacidade limitada de regenerar seus tecidos e órgãos. Um dos mecanismos associados à regeneração natural é a desdiferenciação. Várias moléculas pequenas, como vitamina C e fatores de crescimento, podem melhorar a eficiência da reprogramação. Neste estudo, as células NTERA2-D1 (NT2) foram induzidas à diferenciação (NT2-RA) com ácido retinóico (RA) 10-5 M por três dias e depois submetidas a várias quantidades de humor vítreo (VH). Os resultados mostram que a taxa de crescimento dessas células foi reduzida, enquanto essa taxa foi parcialmente restaurada após o tratamento com VH (NT2-RA-VH). A análise do ciclo celular com o método PI também mostrou que o número de células na fase S do ciclo celular nessas células estava aumentado. Os níveis de antígenos SSEA3 e TRA-1-81 em NT2-RA diminuíram, mas aumentaram em NT2-RA-VH a um nível semelhante ao das células NT2. O nível de SSEA1 teve um padrão oposto. A expressão do gene OCT4 diminuiu após o tratamento com AR, mas foi recuperado em células NT2-RA-VH. Em conclusão, sugerimos o VH como uma mistura potente para melhorar a reprogramação celular levando à desdiferenciação.

Research Progress on Estimation of Postmortem Interval Based on Ocular Tissues Structure / 法医学杂志

Estimation of postmortem interval (PMI) is one of the important research contents in forensic pathology, and it has always been the focus and hot spot of research work. In recent years, scholars at home and abroad have made some research progress in estimating PMI by using ocular tissue. After death, the changes of cornea, aqueous humor, iris, lens, vitreous humor and retina all show time sequence change rule highly related to PMI. This paper reviews the research progress of PMI estimation based on the morphological, biochemical, molecular and genetic material changes of different ocular tissue structures after death, and discusses the existing problems and development trends.

Changes of 1, 5-AG in Vitreous Humor of Rabbit Cadavers with Hyperglycemic Metabolism / 法医学杂志

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.

Effect of anti-vascular endothelial growth factor therapy on intraocular inflammatory cytokine levels in the treatment of proliferative diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the effects of anti-vascular endothelial growth factor(VEGF)agents(Conbercept)before pars plana vitrectomy(PPV)on inflammatory cytokine levels of patients with proliferative diabetic retinopathy(PDR).METHODS: A total of 49 patients(49 eyes)who diagnosed with PDR at the First Affiliated Hospital with Nanjing Medical University from June 2017 to January 2018 were recruited and randomly divided into two groups. A total of 25 cases(25 eyes)who did not receive intravitreal injection before PPV were included in no-intravitreal injection of Conbercept(IVC)group, and 24 cases(24 eyes)who received IVC 5～7d before PPV were included in IVC group. The vitreous samples were collected from all the patients at the start of PPV. Levels of VEGF-A, monocyte chemotactic protein-1(MCP-1)and inflammatory cytokines in the vitreous humor were measured using Luminex technology.RESULTS: Compared with the no-IVC group, the level of VEGF-A decreased significantly(P&#x003C;0.001), the concentration of IL-6(P=0.004), IL-8(P=0.002), IL-18(P=0.04)and TNF-α(P=0.03)increased remarkably in the IVC group. The other inflammatory cytokines in the vitreous humor showed no significant difference between the IVC and no-IVC groups.CONCLUSION: IVC before PPV can effectively decrease the concentration of VEGF-A, but had limited influence on the level of inflammatory cytokines in the vitreous humor of patients with PDR.

Inferring Postmortem Submersion Interval in Rats Found in Water Based on Vitreous Humor Metabolites / 法医学杂志

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.

Research progress of metabolomics in diabetic retinopathy / 中华实验眼科杂志

Diabetic retinopathy (DR) is one of the serious complications of diabetes, and its complex pathogenesis has not been completely clarified yet.Metabolic changes are closely related to phenotypes and metabolomics analysis can indicate the biochemical status of cells, tissues or organs.With the renewal of metabolomics technology and the improvement of detection sensitivity, more differential metabolites have been detected.Therefore, metabolomics has gradually become a powerful tool to explore the pathogenesis of DR and the therapeutic potential of drugs for DR.Metabolomics study in DR is still in its infancy, which mainly takes vitreous humor, aqueous humor and plasma as samples with the pentose phosphate pathway, arginine and proline pathway and ascorbic acidic pathway as main research pathways.Further research is necessary to explore the pathogenesis, diagnosis and treatment of DR, and to determine its longitudinal association with the disease.Metabolomics studies related to the animal model of DR and the vitreous humor, aqueous humor and plasma of DR patients were reviewed in this article.

Usefulness of aqueous and vitreous humor analysis in infectious uveitis

OBJECTIVE: To evaluate the role of intraocular fluid analysis as a diagnostic aid for uveitis. METHODS: Twenty-eight samples (27 patients including 3 HIV-infected patients) with active (n=24) or non-active (n=4) uveitis were submitted to aqueous (AH; n=12) or vitreous humor (VH) analysis (n=16). All samples were analyzed by quantitative PCR for herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV) and Toxoplasma gondii. RESULTS: The positivity of the PCR in AH was 41.7% (5/12), with 50% (2/4) in immunocompetent and 67% (2/3) in HIV+ patients. The positivity of the PCR in VH was 31.2% (5/16), with 13% (1/8) in immunocompetent and 50% (4/8) in immunosuppressed HIV negative patients. The analysis was a determinant in the diagnostic definition in 58% of HA and 50% of VH. CONCLUSION: Even in posterior uveitis, initial AH analysis may be helpful. A careful formulation of possible clinical diagnosis seems to increase the chance of intraocular sample analysis being meaningful.

Intravitreal neurodegenerative and inflammatory mediators in proliferative diabetic retinopathy / Mediadores intravítreos da neurodegeneração e inflamação na retinopatia diabética proliferativa

ABSTRACT Purpose: To compare the intravitreal concentrations of cellular mediators involved in neurodegeneration, inflammation, and angiogenesis in patients with proliferative diabetic retinopathy and other vitreoretinal diseases. Methods: A multiplex bead immunoassay was used to measure vitreous levels of pigment epithelium-derived factor, serum amyloid P, C-reactive protein, complement C4, alpha-1 antitrypsin, vascular endothelial growth factor, platelet-derived growth factor-AA, platelet-derived growth factor-BB, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor alpha and beta in patients undergoing 23-gauge vitrectomy for proliferative diabetic retinopathy and other diagnoses (control group). Results: We evaluated 55 patients, of whom 24 had proliferative diabetic retinopathy and 31 had other diagnoses including vitreous hemorrhage, retinal detachment, macular hole, and epiretinal membrane. Patients with proliferative diabetic retinopathy demonstrated increased levels of serum amyloid P (85.49 vs. 31.38 ng/mL); C-reactive protein (59.89 vs. 41.75 ng/mL), vascular endothelial growth factor (2,330.11 vs. 554.25 pg/mL; p<0.001), platelet-derived growth factor A (127.32 vs. 39.11 pg/mL), platelet-derived growth factor B (29.37 vs. 7.12 pg/mL), interleukin-6 (69.37 vs. 33.58 pg/mL), interleukin-8 (175.25 vs. 59.71 pg/mL), and interleukin-10 (3.70 vs. 1.88 pg/mL); all p<0.004 when compared with the control group. Levels of pigment epithelium-derived factor (30.06 vs. 27.48 ng/mL; p=0.295), complement C4 (570.78 vs. 366.24 ng/mL; p=0.069), and alpha-1-antitrypsin (359.27 vs. 522.44 ng/mL; p=0.264) were not significantly different between the groups. Intravitreal levels of tumor necrosis factor-alpha and tumor necrosis factor-beta were undetectable. Serum Amyloid P, C-reactive protein, platelet-derived growth factor A, platelet-derived growth factor B, interleukin-6, and interleukin-8 were correlated positively with vascular endothelial growth factor. Conclusions: Cellular mediators involved in neurodegeneration and inflammation demonstrated increased levels in the vitreous humor of patients with proliferative diabetic retinopathy and may be part of the pathogenesis of diabetic retinopathy.

RESUMO Objetivo: Comparar as concentrações intravítreas de mediadores celulares envolvidos na neurodegeneração, inflamação e angiogênese em pacientes com retinopatia diabética proliferativa e outras doenças vítreo-retinianas. Métodos: Um ensaio imunomagnético foi utilizado para medir os níveis vítreos do fator derivado do epitélio pigmentar, amilóide P sérico, proteína-C-reativa, complemento C4, e alfa-1-antitripsina, fator de crescimento do endotélio vascular, fator de crescimento derivado das plaquetas AA, fator de crescimento derivado das plaquetas BB, interleucina-6, interleucina-8, interleucina-10, fator de necrose tumoral alfa e beta em pacientes submetidos à vitrectomia 23-gauge para retinopatia diabética proliferativa ou outros diagnósticos (grupo controle). Resultados: Foram avaliados 55 pacientes, dos quais 24 tinham retinopatia diabética proliferativa e 31 tinham outros diagnósticos, incluindo hemorragia vítrea, descolamento de retina, buraco macular e membrana epirretiniana. Pacientes com retinopatia diabética proliferativa demonstraram níveis aumentados de amilóide P sérico (85,49 vs 31,38 ng/mL), proteína-C-reativa (59,89 vs 41,75 ng/mL), fator de crescimento do endotélio vascular (2.330,11 vs 554,25 pg/mL, p<0.001), fator de crescimento derivado das plaquetas-A: (127,32 vs 39,11 pg/mL), fator de crescimento derivado das plaquetas-B (29,37 vs 7,12 pg/mL), interleucina-6 (69,37 vs 33,58 pg/mL), interleucina-8 (175,25 vs 59,71 pg/mL) e interleucina-10 (3,70 vs 1,88 pg/mL), todos com p<0,004 quando comparados ao grupo controle. Níveis de fator derivado do epitélio pigmentar (30,06 vs 27,48 ng/mL; p=0,295), complemento C4 (570,78 vs 366,24 ng/mL; p=0,069), alfa-1 antitripsina (359,27 vs 522,44 ng/mL; p=0,264) não foram significativamente diferente entre os grupos. Níveis intravítreos de fator de necrose tumoral alfa e fator de necrose tumoral beta foram indetectáveis. O amilóide P sérico, a proteína C-reativa, o fator de crescimento derivado das plaquetas A e B, a interleucina-6 e a interleucina-8 correlacionaram-se positivamente com o fator de crescimento do endotélio vascular. Conclusões: Os medidores celulares envolvidos na neurodegeneração e inflamação demonstraram níveis aumentados no humor vítreo de pacientes com retinopatia diabética proliferativa e podem ser parte da patogênese da retinopatia diabética.

Research Progress on Postmortem Interval Estimation by Vitreous Humor / 法医学杂志

Postmortem interval (PMI) estimation is one of the most challenging problems in the field of forensic science. Vitreous humor is a hotspot which has been used for PMI estimation and postmortem chemical analysis in forensic pathology. In order to provide novel perspectives for the future research of PMI estimation using vitreous humor, the comparison between vitreous humor with other common body fluids, the effect of temperature on vitreous humor, vitreous humor detection method and data fitting method have been reviewed in this paper.

Research Progress of Vitreous Humor Detection Technique on Estimation of Post-mortem Interval / 法医学杂志

Estimation of postmortem interval(PMI)plays a crucial role in forensic study and identifica-tion work. Because of the unique anatomy location, vitreous humor is considered to be used for estima-ting PMI, which has aroused interest among scholars, and some researches have been carried out. The detection techniques of vitreous humor are constantly developed and improved which have been gradually applied in forensic science, meanwhile, the study of PMI estimation using vitreous humor is updated rapidly. This paper reviews various techniques and instruments applied to vitreous humor detection, such as ion selective electrode, capillary ion analysis, spectroscopy, chromatography, nano-sensing technology, automatic biochemical analyser, flow cytometer, etc., as well as the related research progress on PMI es-timation in recent years. In order to provide a research direction for scholars and promote a more accu-rate and efficient application in PMI estimation by vitreous humor analysis, some inner problems are also analysed in this paper.

Expression of VEGF in vitreous humor of patients with age-related macular degeneration and its relationship with inflammation / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To analyze the expression of vascular endothelial growth factor(VEGF)in vitreous humor of patients with age-related macular degeneration(ARMD)and its relationship with inflammation. <p>METHODS:Clinical data of 61 patients with ARMD(61 eyes)received treatment at our hospital from September 2016 to September 2017 were analyzed as Group A. And 25 idiopathic macular hole(IMH)patients(25 eyes)were enrolled as Group B. VEGF, IL-6 and IL-10 levels in vitreous humor were tested and compared between the two group. <p>RESULTS: Group A patients had higher levels of VEGF and IL-6 in vitreous humor than these of Group B patients, the difference were statistically significant(<i>t</i>=32.530, 8.443; <i>P</i><0.01). The level of IL-10 between the two groups was not significantly different(<i>P</i>>0.05). ROC analysis showed that the VEGF cut-off point value of 460.6pg/mL, as used for the differential diagnosis between ARMD and IMH, provided a sensitivity of 84.00%, a specificity of 93.44%, area under the curve(AUC)was 0.879, better than these of IL-6. Correlation analysis showed that, for Group A patients, the levels of VEGF had significant positive correlation with IL-6(<i>r</i>=0.787, <i>P</i><0.01). <p>CONCLUSION: The level of VEGF increased significantly in patients with ARMD and had positive correlation with inflammation, which can be used as an auxiliary diagnosis marker for ARMD from IMH.

Correlation between postmortem intervals and the changes of K+ concentration in rabbit vitreous humor after death under different temperature / 中国法医学杂志

Objective To investigate the relationship between K+ concentration in rabbit vitreous humor and postmortem interval (PMI) under different ambient temperature. Methods Rabbit corpses were stored at 5℃ , 15℃ , 25℃ , and 35℃ after execution, and 80~100μL vitreous humor was extracted from each eye of the rabbit in turn every 12 hours. The concentrations of K+ were examined by Modular DPPI automatic biochemistry analyzer. The Interpolation Functions were used to analyze the statistical relationship between PMI and K+ concentration under different temperature. Results In each animal group, K+ concentration increased with PMI. Equation was obtained after interpolation analysis on range of temperature 5℃ ~30℃ . The three-variable quintic surface equation was f(x,y)=-1.998e14+1.345e12x+5.902e13y+0.005585x2-4.509e11xy-3.876e12y2-0.0002868x3+0.003545x2y+4.406e10xy2-1.746e10y3+2.669e-6x4-1.568e-5x3y-0.0001771x2y2-1.64e9xy3+6.669e9y4-8.672e-9x5+4.467e-8x4y+2.354e-7x3y2+2.459e-6x2y3+2.05e7xy4-1.214e8y5(R2=0.9956), x stands for temperature, y stands for K+ concentration, f(x,y) stands for PMI. Conclusion The rule of K+ concentration changes at ambient temperature complied with three-variable quintic surface equation distribution. Measurement of interpolation function may be used for PMI estimation at different ambient temperature.

Usefulness of Dipstick Test for Vitreous Glucose in Autopsy Practice / 대한법의학회지

The concentration of glucose in the vitreous humor serves as an important diagnostic marker for diabetic mellitus in post-mortem examinations, as the vitreous humor can be easily collected and the glucose test using vitreous humor is not significantly affected by cell autolysis and hemolysis. For a quick and effective glucose test, we suggest a dipstick test of the vitreous humor during autopsy. The results were evaluated and compared with other methods for significance testing. In this study, vitreous humor was analyzed from 257 autopsy cases. Qualitative concordance rate of the dipstick test for glucose and the hexokinase test was 98.7%, positive prediction rate was 89.6%, and negative prediction rate was 100%. However, there was no significant correlation between the dipstick glucose test and the hexokinase test. We conclude that the dipstick glucose test is effective and useful for post-mortem glucose screening testing and for additional post-mortem diabetes testing. Recently, the importance of post-mortem glucose testing has increased with the increase in deaths from diabetes complications. The use of the dipstick glucose test in autopsy practice can improve forensic medicine in Korea.

Estimation of postmortem interval by determination of K~+ concentration in aqueous humor / 中国法医学杂志

Objective To investigate the applicability of the K~+ concentration in aqueous humor to estimate postmortem interval(PMI).Methods 30 White New-Zealand rabbit were sacrificed by air embolism and divided into 10 groups.Aqueous humor and vitreous humor were sampled at 0.5h,1h,3h,6h,8h,12h,16h,20h,and 24h after death.The concentration of potassium,sodium and calcium were analyzed by an autoanalyzer and the data were statistically processed by SPSS software for Windows.Results Increase in potassiam concentration in aqueous humor was correlated with the postmortem interval(R~2=0.956).Conclusion Measurement of potassium concentration in aqueous humor may be used for PMI estimation.

Assessing the suitability of vitreous humor as a sample for toxicological analysis – A prospective study.

The incidence of poisoning and substance abuse have been steadily rising in India over the last few decades. Accurate diagnosis of poisoning is essential, both in the living as well as in the dead, for therapeutic and medicolegal purposes respectively. Poisons are generally detected in body fluids such as urine, blood, or gastric lavage during life, while they are detected in the contents of stomach, bowel and the viscera, besides urine and vomitus, after death. In a dead body, one of the better samples to complement blood is vitreous humor, because it is less likely to degrade quickly, and is fairly easy to collect at autopsy. In this study, an attempt has been made to assess the role of vitreous humor as a suitable sample for toxicological analysis in the detection of all kinds of poisoning after death. The study was done on alleged cases of poisoning subjected to medicolegal autopsy at the mortuary of Government Medical College and Hospital, Chandigarh. Attempt was also made to corelate the vitreous humor findings with that of the official report from the Chemical Examiner's Laboratory at the state or central level.

Concentration changes of electrolytes in vitreous humor of acidosis associated with different postmortem interval in rabbits / 重庆医科大学学报

Objective:To investigate the chemical composition changes in vitreous humor of rabbits at different times after the death of acute acidosis. Methods: 30% Sodium Dihydrogen Phosphate were used in rabbits to induce the animal model of acute acidosis,and we observed the ionic concentration changes in vitreous humor at different times. Results:72 hours after the death of acute acidosis,the concentration of Potassium,Magnesium,Phosphorus in vitreous humor were gradually increased and Calcium were decreased gradually with the time of death. Sodium performance instability,the change of chlorinity firstly decreased and then increased.Potassium ions was closely related to death time (R2=0.976 1). Conclusion:After the death of acute acidosis,the concentration of Potassium in the vitreous humor of rabbits can be used to infer PMI in the death of acute acidosis.

Comparative Study of Two Vitreous Humor Sampling Methods in Rabbits / 华中科技大学学报（医学）（英德文版）

To compare and evaluate two methodologies, entire-sampling and micro-sampling for the harvesting of vitreous humor, the vitreous humor of rabbits were sampled with the two methods respectively, and the concentrations of calcium, chlorine, potassium, sodium and phosphorus of the were measured. The results showed that the differences in the variance coefficient and two-eye concentrations of micro-sampled specimens were less than those of the entire-sampled specimens. In the micro-sampling group, the concentrations of repeated micro-sampling showed no differences among different groups (P＞0.05) and the intra-ocular fluid dynamics did not have significant influence on post-mortem sampling. The sampling technique may affect the concentrations of specimen collected.Our study suggests that micro-sampling is less influenced by the human factor and is reliable, reproducible, and more suitable for forensic investigation.

Changes of Ionic Flow through the Internal Limiting Membrane during the Visual Adaptation of Vertebrate Eye

It already has been known that various ions were participated in phototransduction mechanism of the vertebrate photoreceptor during the visual adaptation. The vitreous humor(VH)contains certain amount of Na+, K+ and Ca++ as well. However, the roles of these ions are unknown except functioning of metabolic process. Our preliminary electroretinogram(ERG) experiments suggested that the permeability of these ions has light dependent activity during the light illumination. We have supported this suggestion more tangibly by trying out various experiments with bullfrog eyes as a reference of visual adaptation. The results are summarized as follows: 1)According to our atomic absorption spectroscopic measurements, the concentration of Na+, K+ and Ca++ in light adapted VH was higher than that of dark adapted VH. This result indicated that the light-dependention transport systems which affect the ionic movements might be in internal limiting membrane(ILM). 2)The amplitude of ERG b-wave was reduced by concentration decrement of Na+ and concentration increment of K+ respectively. On the other hand, the elimination of Ca++ within ringer solution resulted in b-wave amplitude increment. 3)Treatment of Na+ hannel blockers(TTX, STX)and K+ channel blockers(Ba++, Cd++, Cs+, 4-AP and TEA)in the vitreous humor side induced the increment and the decrement of b-wave response respectively. Taken together, these results suggest that the light dependent Na+ K+ channels exist in the ILM of vertebrate retina which participates visual adaptation.

Biochemical Analysis on Postmortem Specimens / 대한법의학회지

Because the postmortem changes rapidly distort values of many constituents in the body fluids, the determination of postmortem chemical changes and relation among body fluids is very important in medicolegal community. A laboratory result is not useful if appropriate data for comparison are lacking. The aim of this paper is to determine the reference ranges and the postmortem changes for chemical constituents in postmortem specimen. We examined 17 clinical laboratory parameters in cadaveric blood and vitreous humor obtained from 51 autopsy cases. The mean, standard error, standard deviation and confidence interval of all measured constituents were shown in Table 2 & Figure 1. The postmortem blood level of amylase, phosporus, LDH, ALT, AST and CPK are very higher than those of antemortem blood. The postmortem vitreous level of total bilirubin, triglyceride, GGT, alkaline phosphatase, albumin, total protein and cholesterol are very low and is not reliable. The ratio of vitreous/blood in calcium, BUN, creatine and uric acid are 0.74, 0.68, 0.29 and 0.23 in decreasing orders(Table 3,4). For the medical examiner or pathologist, routine chemical examinations of the vitreous humor can provide evidence of abnormality not apparent in gross or microscopic examination of the tissue. A more extensive study will be required, using a larger number of subjects, to establish the full range of variability.