Exploration and Practice of the "One Combination, Two Highlights, Three Combinations, Four in One" Innovative Talents Training Mode in Forensic Medicine / 法医学杂志

Talent is one of the basic and strategic supports for building a modern socialist country in all aspects. Since the 1980s, the establishment of forensic medicine major and the cultivation of innovative talents in forensic medicine have become hot topics in higher education in forensic medicine. Over the past 43 years, the forensic medicine team of Shanxi Medical University has adhered to the joint education of public security and colleges, and made collaborative innovation, forming a training mode of "One Combination, Two Highlights, Three Combinations, Four in One" for innovative talents in forensic medicine. It has carried out "5+3/X" integrated reform, and formed a relatively complete talent training innovation mode and management system in teaching, scientific research, identification, major, discipline, team, platform and cultural construction. It has made a historic contribution to China's higher forensic education, accumulated valuable experience for the construction of first-class major and first-class discipline of forensic medicine, and provided strong support for the construction of the national new forensic talent training system. The popularization of this training mode is conducive to the rapid and sustainable development of forensic science, and provides more excellent forensic talents for national building, regional social development and the discipline construction of forensic science.

Application Prospects and Prospect of Metabolomics in the Identification of Sudden Cardiac Death / 法医学杂志

In cases of sudden death, the prevention of sudden cardiac death and the analysis of the cause of death after sudden cardiac death have always been a difficult problem. Therefore, clinical research and forensic pathological identification of sudden cardiac death are of great significance. In recent years, metabolomics has gradually developed into a popular field of life science research. The detection of "metabolic fingerprints" of biological fluids can provide an important basis for early diagnosis of diseases and the discovery of potential biomarkers. This article reviews the current research status of sudden cardiac death and the research on metabolomics of cardiovascular diseases that is closely related to sudden cardiac death and analyzes the application prospects of metabolomics in the identification of the cause of sudden cardiac death.

Correlation between the Polymorphism of Coagulation-Related Genes and Lower Extremity Deep Venous Thrombosis / 法医学杂志

Objective To investigate the correlation between the polymorphism of 4 coagulation-related genes, rs1799963 （coagulation factor V gene Leiden）, rs6025 （prothrombin gene G20210A）, rs1042579 （thrombomodulin protein gene c.1418C>T） and rs1801131 （methylenetetrahydroflate reductase gene） and lower extremity deep venous thrombosis （LEDVT）. Methods The 4 genotypes mentioned above of 150 LEDVT patients and 153 healthy controls were detected by the kompetitive allele specific polymerase chain reaction （KASP）, then related blood biochemical indicators were collected, binary Logistic regression was established to screen the independent risk factors of LEDVT, and the correlation between polymorphism of 4 coagulation-related genes and LEDVT and its indicators under different genetic modes after adjusting confounding factors were analyzed. Results Five variables, D-dimer, fibrinogen degradation product, homocysteine, sex and age might be the risk factors of LEDVT. These variables were put into 4 genetic inheritance models, and adjusted in binary Logistic regression. The results suggested that the mutations of rs1042579 were correlated with LEDVT under dominant inheritance mode. Conclusion The gene polymorphism of rs1799963, rs6025 and rs1801131 has no significant correlation with the formation of LEDVT. The gene polymorphism of rs1042579 plays a role under dominant inheritance mode, and might be an independent risk factor for formation of LEDVT.

Estimating Postmortem Interval by Protein Chip Detection Technology Combined with Multidimensional Statistics / 法医学杂志

Objective To obtain the protein expression profile of rat liver tissue after death by the 2100 bioanalyzer combined with protein chip, and infer the relationship between protein expression profile and postmortem interval. Methods Rats were killed by abdominal anesthesia and placed at 16 ℃. Water-soluble proteins in liver tissues were extracted at 14 time points after death. The expression profile data of proteins with relative molecular weight of 14 000-230 000 were obtained using protein chip, and principal component analysis （PCA）, partial least squares-discriminant analysis （PLS-DA） and Fisher discriminant were used to analyze the data. Results According to the changes of protein expression profile, the postmortem interval was divided into group A （0 d）, group B （1-9 d）, group C （12-30 d） according to the result of PLS-DA. The prediction accuracy of the training set and test set of the model were all 100.0%, and the internal cross-validation of the training set was 100.0% according to Fisher discriminant. The Fisher discriminant model at each time point of group B and C was established to narrow the time window of postmortem interval estimation. The prediction accuracy of the training set and test set were all 100.0%, and the internal cross-validation accuracy of the training set was 100.0% in group B. The prediction accuracy of the training set and test set were respectively 95.2% and 78.6% in group C, and the internal cross-validation of the training set was 88.1%. Conclusion Protein chip detection technology can quickly and easily obtain the expression profile of water-soluble proteins of rat liver tissue with a relative molecular weight of 14 000-230 000 at different time points after death. PLS-DA and Fisher discriminant models are established to classify and predict the postmortem interval, in order to provide new ideas and methods for postmortem interval estimation.

Expression of Autophagy-Associated Protein in Rat Muscle Tissues after Antemortem and Postmortem Injury / 法医学杂志

Objective To study the expression of the three autophagy-associated proteins, BECN1, LC3 and p62, after the injury of the skeletal muscle of rats and to explore its application in differentiation between antemortem and postmortem injury. Methods The 72 healthy Sprague-Dawley rats were randomly divided into the undamaged control group, the antemortem injury group （0.5 h, 1 h, 2 h, 4 h, 8 h, 16 h and 24 h） and postmortem injury group （0.5 h, 1 h, 2 h and 4 h）. A model of the injured right hind limb of rats was constructed. The expressions of the autophagy-associated proteins, BECN1, LC3-2/LC3-1 and p62, in the control group, the antemortem injury group and postmortem injury group were detected by Western blotting method. The data were respectively centralized and standardized and the orthogonal partial least square-discrimination analysis （OPLS-DA） identification model of antemortem and postmortem injury groups was constructed. Results The expression of BECN1, p62 protein and LC3-2/LC3-1 after the injury of the skeletal muscle of the rats showed different degrees of changes, but the differences among the 3 groups had no statistical significance. Antemortem and postmortem injury groups can be distinguished by centralizing and standardizing the expression levels of autophagy protein BECN1 and the ratio of LC3-2/LC3-1. The principal components extracted from OPLS-DA model of antemortem injury and postmortem injury had a relatively good interpretation of the model （Rx2=0.563, Ry2=0.439）, but it were less predictive （Q2=0.366）. Conclusion The expression of BECN1 and the ratio of LC3-2/LC3-1 in injured local tissue of the rat skeletal muscle can be used for the differentiation of antemortem injury group and postmortem injury group.

Wound Age Estimation by Neutrophil Migration Distance / 法医学杂志

Objective To explore the application of neutrophil migration distance for wound age estimation of skeletal muscles in rats, and to provide methodological basis for follow-up study in future. Methods The skeletal muscle contusion model was established in rats, and the control group and the 2, 4, 6 h post-traumatic groups were set. The law of response of neutrophils that participated in the inflammation after injury was detected by immunohistochemical staining, and the relationship between neutrophil migration distance and injury time was detected by TissueFAXS PLUS software. Results The skeletal muscle was obviously infiltrated with neutrophils 2-6 h after injury. The positive rate of neutrophil was （28.75±0.94）% at 2 h post-traumatic, and reached the peak （45.50±3.63）% at 4 h post-traumatic, then decreased to （31.92±1.56）% at 6 h post-traumatic. The neutrophil migration distances increased with the progress of inflammation, and reached （124.80±12.32） μm, （229.03±21.45） μm and （335.04±16.75） μm at 2 h, 4 h and 6 h, respectively. Conclusion There is a relationship of neutrophil infiltrated number and migration distance and wound age within the 2-6 h after skeletal muscle injury, which could be used for the inference of skeletal muscle wound age.

Combination of mRNA of Repair-related Genes in Rat Skeletal Muscles for Wound Age Estimation / 法医学杂志

Objective To investigate the estimation of early and mid-term wound age by a combination of four mRNAs, the DNA polymerase delta-interacting protein 3 （POLDIP3） mRNA, regulator of chromosome condensation 1 like （RCC1L） mRNA, proline-rich 5 （PRR5） mRNA, and ribonucleic acid export 1 （RAE1） mRNA in rats skeletal muscles. Methods The model of rat skeletal muscle contusion was established, and then contusion area muscle tissue was extracted 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44 and 48 h after injury. Histomorphological changes during the repair process after rat skeletal muscle contusion were observed. The relative expressions of Poldip3, Rcc1l, Prr5 and Rae1 mRNAs were detected by reverse transcription real-time quantitative polymerase chain reaction （RT-qPCR）. Different stages of wound age were classified by using the expression patterns of four genes at various time points after injury. The accuracy of the results was verified by Fisher discriminant analysis. Results Histomorphological results showed that the repair process after skeletal muscle contusion occurred with the prolonging of time. Through combination of the expression trends of the four kinds of mRNAs, the 48 h after injury could be divided into three periods, 4-12 h, 16-28 h and 32-48 h. The Fisher discrimination method showed that the classification accuracy rates of the three periods were 83.3%, 75.0% and 73.3%, respectively. Conclusion The classification discrimination based on the relative expression of every gene has a higher accuracy, and the accuracy of wound age estimation with combination of mRNA relative expressions is higher than that with a single indicator. By combining with Fisher discrimination method, this method can be used for early and mid-term wound age estimation.

Time-dependent Expression of Nrf2 Protein and its Effects on Wound Repair in Skeletal Muscle / 法医学杂志

Objective To detect the expression of nuclear factor erythroid 2-related factor 2(Nrf2)to explore its change rule and effects in the repair process of skeletal muscle. Methods An injury model of skeletal muscle was established by injection of cardiotoxin into the gastrocnemius muscle of SD male rats. The muscle samples were taken from control group and injury group at each time point(1 h, 4 h, 8 h, 12 h, 16 h, 1 d, 3 d, 5 d, 7 d, 9 d, 13 d, 17 d, 21 d). The morphological changes of skeletal muscle in repair process were observed by H&E staining, and the content of reactive oxygen species(ROS)was detected. The expression level of Nrf2 protein was investigated by Western blotting and immunohisto-chemistry staining. Results After the skeletal muscle injury, the injury region was infiltrated with inflam-matory cells which constituted mainly by lymphocyte neutrophils and mononuclear cells. There were large amounts of immature muscle cells appeared at the 5th day and the muscle repair was completed at the 21th day. Comparing with control group, the ROS content decreased in injury group at the 12th hour(P<0.05), while Nrf2 expression increased at the 16th hour(P<0.05). Moreover, the positive rate of Nrf2 increased after injury, and peaked at 16 h-1 d, then decreased gradually and returned to the level of control group(P<0.05). Conclusion The Nrf2 protein involves in the regulation of the repair of skeletal muscle injury. The positive rate of Nrf2 shows a time-dependent expression, which can be used to esti-mate the wound age of skeletal muscle.

Study on Urinary Metabolic Profile in Rats with Deep Venous Thrombosis Based on Pattern Recognition / 法医学杂志

OBJECTIVES@#To study the urinary metabolic profile in rats with deep venous thrombosis （DVT） based on metabolomics and to screen out small molecular biomarkers for the diagnosis and forensic identification of DVT.@*METHODS@#Inferior vena cava of rats was ligated to construct DVT models. The rats were randomly divided into three groups： DVT, sham, and control groups, 10 in each group. The urine of DVT and sham rats was collected during 24 hours in the metabolic cage at 48 hours after operating, meanwhile, 24 hours urine was collected in control group. The metabolic profile was analyzed by nuclear magnetic resonance. SIMCA-P 14.1 software was used for pattern recognition. The variable importance in projection （VIP） value from orthogonal PLS-DA （OPLS-DA） model combined with Mann-Whitney U test were used to search the different metabolites in the urine.@*RESULTS@#The metabolic profiles of urine from DVT, sham, and control groups had significant differences. The DVT, sham, and control groups could be distinguished by the partial least squares method-discriminant analysis （PLS-DA） model. Compared with the urine of the rats in control groups, the levels of leucine, glutamine, creatine, creatinine and sucrose in the urine of DVT rats were up-regulated, and the levels of 3-hydroxybutyrate, lactate, acetone, α-oxoglutarate, citrate and hippurate were down-regulated.@*CONCLUSIONS@#The different metabolites in the urine of DVT rats are expected to become its candidate biomarkers. The results can provide a research basis for the diagnosis, treatment and forensic identification of DVT.

Time-dependent Expression of MT1A mRNA and MT2A mRNA in the Contused Skeletal Muscle of Rats / 法医学杂志

OBJECTIVES@#To investigate the time-dependent expression of metallothionein （MT） 1A mRNA and MT2A mRNA in contused skeletal muscle of rats.@*METHODS@#A total of 54 Sprague-Dawley rats were used in this study. The rats were divided into two parts: control group （n=6） and contusion groups （0.5, 1, 6, 12, 18, 24, 30, and 36 h after contusion, n=6）. Total RNA was extracted from skeletal muscle. The expression levels of MT1A mRNA and MT2A mRNA were detected by SYBR Green I real-time PCR.@*RESULTS@#The expression trends of the two potential marker genes were related to wound age. In addition to 0.5 h, there were significant contrasts between the control group and contused group （P<0.05）, about the expression levels of MT1A mRNA and MT2A mRNA in different phases. As the extension of wound age, the relative expression of MT1A mRNA and MT2A mRNA at 1 h, 6 h, 12 h and 18 h after contusion demonstrated upgrade tendency until its expression levels in 18 h peak with 239.41±15.20 and 717.42±50.76, respectively. When time extends to 24 h after injury, the expression of above two marks decreased, respectively. The MT1A mRNA and MT2A mRNA expression levels increased at 30 h and then decreased.@*CONCLUSIONS@#Determination of MT1A mRNA and MT2A mRNA levels by real-time PCR may be useful for the estimation of wound age.

Expression of SFRP5 mRNA in Rat Skeletal Muscle after Contusion / 法医学杂志

OBJECTIVE@#To investigate the relationship between the expression of secreted frizzled-related protein 5 (SFRP5) mRNA and the time interval after skeletal muscle injury in rats by real-time PCR.@*METHODS@#A total of ninety SD rats were randomly divided into the contusion groups at different times including 4h, 8h, 12h, 16h, 20h, 24h, 28h, 32h, 36h, 40h, 44h, 48h after contusion, incision groups at different times including 4h and 8h after incision and the control group. The samples were taken from the contused zone at different time points. The total RNA was isolated from the samples and reversely transcribed to analyze the expression levels of SFRP5 mRNA.@*RESULTS@#Compared to the control group, the expression of SFRP5 mRNA in contusion groups were down-regulated within 48 h after contusion and reached the lowest level at 20 h, and the expression of SFRP5 mRNA gradually increased from 20 h to 48 h after contusion. The expression of SFRP5 mRNA in the incised groups were significantly lower than that of the contusion groups at 4 h after injury. At the time of 8 h, the expression levels between the contusion and incision groups showed no statistically significant difference.@*CONCLUSION@#It is suggested that SFRP5 mRNA analysis may show regular expression and can be a marker for estimation of skeletal muscle injury age.

Relation between Injury Time and the Expression of COX6C mRNA in Skeletal Muscle of Rats after Contusion / 法医学杂志

OBJECTIVE@#To investigate the relation between injury time and the expression of cytochrome c oxidase subunit VIc (COX6C) mRNA in skeletal muscle of rat after contusion.@*METHODS@#A total of fifty-four SD rats were divided into the control group and the contusion groups (0.5, 1, 6, 12, 18, 24, 30, and 36 h after contusion), randomly. The contusion model was established by free fall drop of gravity hammer. At corresponding time point after contusion, the regular histology was examined and expression level of COX6C mRNA was tested by real-time PCR after extraction of total RNA from the tissues.@*RESULTS@#The main pathological features of 6 h after injury included edema and hemorrhage in myocytes with no inflammatory cells found. After 6 hours, the findings included myocyte degeneration and necrosis, inflammatory cells infiltration, and fibrous connective tissue proliferation in the contused zone. The expression level of COX6C mRNA was higher than that of the control group within 6 h after contusion. The expression level was lower than that of the control group from 6-36 h after contusion.@*CONCLUSION@#The level of COX6C mRNA expresses in a regular way after contusion. It may be useful for estimating wound age in combination with the results of pathological features.

Relative Expression of Indicators for Wound Age Estimation in Forensic Pathology / 法医学杂志

OBJECTIVE@#In order to understand which kind of function genes play an important role for estimating wound age, the variation of difference genes' mRNA expression were compared after injury.@*METHODS@#The mRNA expression levels of seven candidate genes (ICAM-1, NF-κB, MX2, MT1, MT2, sTnI, and Cox6c) were analyzed in contused rat skeletal muscle at different time points using real-time fluorescent quantitative PCR (RT-qPCR). The raw Ct values were normalized relative to that of RPL32 mRNA, and converted to standard Ct values. At each time point after injury, the standard deviations (SD) of the standard Ct values were calculated by SPSS.@*RESULTS@#The expression trends of the seven genes were all found to be related to wound age, but there were lower variation coefficients and greater reliability of s TnI and Cox6c when compared with other genes.@*CONCLUSION@#The genes encoding structural proteins or proteins that perform basic functions can be suitable for wound age estimation.

Protective effects of intermedin preconditioning on hypoxic injury in rat's cardiac myocytes / 法医学杂志

OBJECTIVE@#To observe the effects of intermedin preconditioning on hypoxic injury in rat's cardiac myocytes and to provide the hypothetical mechanism of sudden cardiac death in the field of forensic pathology.@*METHODS@#The H9c2 cultured rat cardiac myocytes were randomly divided into control group, hypoxia group and IMD group. The myocardial cell viability, cellular ultrastructure, intracellular calcium concentration and apoptosis rate were determined by MTT assay, transmission electron microscopy, laser scanning confocal microscope and flow cytometry, respectively.@*RESULTS@#Compared with the control group, cell viability obviously decreased with inner ultrastructure injury in the hypoxia group (P<0.05), while cell viability significantly increased in the IMD group by reducing the hypoxia injury of cardiac myocytes (P<0.05). Compared with the control group, [Ca2+]i (fluorescence intensity) and apoptosis rate significantly increased in the hypoxia group, but decreased in the IMD group (P<0.05).@*CONCLUSION@#IMD increases the cell survival rate and decreases the cell apoptosis inhibited by intracellular calcium overload from hypoxia. This finding may reveal the mechanism of protective effects of myocardial hypoxia, and provide a scientific basis for the identification sudden cardiac death.

Effect and mechanism of intermedin in acute rat cardiac ischemic injury / 法医学杂志

OBJECTIVE@#To investigate the effect and potential mechanism of intermedin (IMD) in acute cardiac ischemic injury and to provide a new approach for exploring mechanism of sudden cardiac death.@*METHODS@#Seventy-two healthy male rats were randomly divided into 3 groups: control, ischemic and the IMD-treated group. The activity of lactate dehydrogenase (LDH), malondialdehyde (MDA) and superoxide dismutase (SOD) in heart blood were tested by enzyme chemistry method. The mRNA changes of calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins (RAMPs) in cardiac were measured by real-time PCR analysis. Myocardial cyclic adenosine monophosphate (cAMP) content was determined by enzyme linked immunosorbent assay (ELISA). Apoptosis related factors Bcl-2 and Bax were detected by immunohistochemistry.@*RESULTS@#Comparing with the control group, LDH and MDA activity of ischemic group in heart blood increased and SOD activity decreased. The concentration of cAMP increased in ventricular muscle, Bcl-2 and Bax proteins expression ratio level decreased. The intravenation of IMD decreased the level of increased activity of LDH and MDA, and lessened the level of decreased activity of SOD. The mRNA expression of CRLR and RAMPs obviously increased in ventricular muscle.@*CONCLUSION@#The protective effect of IMD against myocardial ischemic injury could be caused by decreasing the oxidative stress of ischemia and inhibiting the myocardial apoptosis.

Expression of microtubule associated protein-2 mRNA after cerebral contusion / 法医学杂志

OBJECTIVE@#To explore the mRNA expression of microtubule associated protein-2 (MAP-2) after cerebral contusion, and to investigate its relationship with post-injury interval in a rat model of cerebral contusion.@*METHODS@#Based on Feeney's model of cerebral contusion, the time-dependent changes of MAP-2 mRNA were detected by real-time PCR method in different groups.@*RESULTS@#MAP-2 mRNA showed a lower expression in the brain of the control group. The expression of MAP-2 mRNA decreased 1 h post-injury, and reached the lowest level at 6 h, and the expression of MAP-2 mRNA gradually increased in the focus of the cerebral contusion from 12h to 14d after contusion, which kept a high level up to 14 d post-injury.@*CONCLUSION@#The time-dependent changes of MAP-2 mRNA expression may be a new method for estimating the wound age of cerebral contusion in forensic practice.

The degradation of housekeeping mRNA in dead rats by real-time RT-PCR / 法医学杂志

OBJECTIVE@#To explore the feasibility of real-time RT-PCR of housekeeping mRNA degradation in dead rats in order to seek new suitable techniques for post-mortem interval (PMI).@*METHODS@#The levels of GAPDH mRNA and beta-actin mRNA in the brain and spleen of the rats were measured at different times after death by the SYBR Green I real-time RT-PCR. The relative mRNA level was indicated with the Ct value, then the relationship between the Ct value and PMI were analyzed and the corresponding regression equation was obtained.@*RESULTS@#The Ct values of GAPDH mRNA and beta-actin mRNA by SYBR Green I real time RT-PCR correlated well with the PMI.@*CONCLUSION@#The SYBR Green I real-time RT-PCR is a reliable technique for studying mRNA degradation. Adoption of the housekeeping genes eliminates systematical errors of other genes which have individual difference. As an objective and dynamic indication, Ct value has a good correlation with PMI, and could be applied for estimating PMI, especially in late period.

Changes of ICAM-1 mRNA expression in rats' skin and muscle after contusion / 法医学杂志

OBJECTIVE@#To investigate the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA in contused skin and muscle of rats and the relationship between the ICAM-1 expression and the wound age.@*METHODS@#The samples were taken at 0.5, 1, 6, 12, 18, 24 and 30 h after contusion of rats, respectively. Total RNA was extracted both from the skin and muscle samples of each group and reverse transcription polymerase chain reaction (RT-PCR) was conducted to synthesize the 1st strand cDNA. The amount of ICAM-1 mRNA in each sample was quantified using rp132 intrinsic fluorescent assay and compared by the 2 (-Delta Delta Ct) method with that from control samples.@*RESULTS@#After contusion the expression of ICAM-1 mRNA in skin increased rapidly and peaked at 0.5 h, at 24 h degraded to the amount that was seven times as much as the control group, then rised again. The expression of ICAM-1 mRNA in muscle increased significantly within 0.5 h and peaked at 6 h, reached the minimum at 18 h, then increased again.@*CONCLUSION@#It is suggested that ICAM-1 mRNA analysis may be useful for estimation of early wound age because of its time-related expression after contusion in skin and muscle.

The relationship between the degradation of actin and the postmortem interval in rats / 法医学杂志

OBJECTIVE@#To observe the degradation of actin in cardiac muscle, brain and skeletal muscle of rats after death and to find an objective parameter interval (PMI) estimation.@*METHODS@#Twenty eight clear Sprague Dawley rats put into an artificial climate incubator (set at 20 degrees C) for 0, 24, 48, 72, The actin contents in the above tissues were quantitated by Western-blot Pro Plus 5.0 image analysis system, and were then statistically analyzed@*RESULTS@#Actin content in all these tissues decreased gradually with prolonged differences between the groups was statistically significant (P < 0.05), with fastest, then the lung, the spleen, the liver, the kidney, the cardiac muscle order. There was a strong correlation between actin degradation and determination (R2) exceeded 0.75 in all these tissues.@*CONCLUSION@#degradation, the actin contents in cardiac muscle, liver, spleen, lung, kindey, rats decreased gradually with prolonged PMI, which may potentially be PMI estimation.

The correlation between the DNA content in human thyroid follicular epithelial cells and the postmortem interval / 法医学杂志

OBJECTIVE@#To study the relationship between the DNA content in follicular epithelial cells of the human thyroid and postmortem interval (PMI).@*METHODS@#Changes of the DNA content in thyroid follicular epithelial cells at different PMI were determined by Methyl Green-Pyronin (MGP) stain combined with an image analysis technique.@*RESULTS@#The average DNA content in the thyroid follicular epithelial continued to decrease with increased PMI. The coefficient of determination for DNA content with average gray, aimed area, aimed area ratio and positive index in follicular epithelial cells were 0.960, 0.987, 0.988 and 0.990, respectively.@*CONCLUSION@#There is an apparent correlation between the average DNA content of follicular epithelial cells and the PMI. MGP stain combined with an image analysis technique seems to be a useful means to study the degradation of DNA in thyroid follicular epithelial cells.