Comparison of Application of MD-VF-Auto SEM Method and Plankton Gene Multiplex PCR System in the Diagnosis of Drowning / 法医学杂志

OBJECTIVES@#To compare the application effect of microwave digestion - vacuum filtration - automated scanning electron microscopy (MD-VF-Auto SEM) method and plankton gene multiplex PCR system in the diagnosis of drowning.@*METHODS@#Lung, liver and kidney tissue of 10 non-drowning cases and 50 drowning cases were prepared for further MD-VF-Auto SEM method analysis and plankton gene multiplex PCR system analysis. The positive detection rate of the two methods in each tissue was calculated.@*RESULTS@#The positive rate of the MD-VF-Auto SEM method detecting diatoms in drowning cases was 100%, and few diatoms were detected in the liver and kidney tissues of 6 non-drowning cases. By using the plankton gene multiplex PCR system, the diatom positive rate of drowning cases was 84%, and all the non-drowning cases were negative. There were significant differences in the positive rate of the liver, kidney tissues between MD-VF-Auto SEM method and plankton gene multiplex PCR system (P<0.05), as well as the total positive rate of cases. However, no significant differences were found in the positive rates of lung tissues (P>0.05).@*CONCLUSIONS@#MD-VF-Auto SEM method is more sensitive than plankton gene multiplex PCR system in diatom test. But the plankton gene multiplex PCR system can also detect plankton other than diatoms. Combination of the two methods can provide a more reliable basis for the diagnosis of drowning.

Application of Diatoms Quantitative Analysis in the Diagnosis of Drowning / 法医学杂志

OBJECTIVES@#To retrospectively analyze diatom test cases of corpses in water and discuss the value of quantitative analysis of diatoms in the diagnosis of drowning.@*METHODS@#A total of 490 cases of water-related death were collected. They were divided into drowning group and postmortem immersion group according to the cause of death. Diatoms in lung, liver, kidney tissue and water sample were analyzed quantitatively by microwave digestion-vacuum filtration-automated scanning electron microscopy (MD-VF-Auto SEM) method. The ratios of content of diatoms in lung tissue and water sample (CL/CD) were calculated.@*RESULTS@#The results of diatom test for three organs (lung, liver and kidney) were all positive in 400 cases (85.5%); the content of diatom in lung, liver, kidney tissues, and water samples of drowning group were (113 235.9±317 868.1), (26.7±75.6), (23.3±52.2) and (12 113.3±21 760.0) cells/10 g, respectively; the species of diatom were (7.5±2.8), (2.6±1.9), (2.9±2.1) and (8.9±3.0) types, respectively; the CL/CD of drowning group and postmortem immersion group were (100.6±830.7) and (0.3±0.4), respectively.@*CONCLUSIONS@#Quantitative analysis of diatoms can provide supportive evidence for the diagnosis of drowning, and the parameter CL/CD can be introduced into the analysis to make a more accurate diagnosis of drowning.

Effects of Digestive Temperature and Time on Diatom Test / 法医学杂志

OBJECTIVES@#To study the effects of temperature and time for diatoms digestion and find out suitable digestive temperature and time.@*METHODS@#Eighty pieces of liver tissues were collected, each piece of tissue was 2 g, and 2 mL Pearl River water was added to each piece of tissue. The digestion temperature was set at 100 ℃, 120 ℃, 140 ℃, 160 ℃, 180 ℃ and the digestion time was set at 40, 50, 60, 70, 80 min. The liver tissue and water mixture were divided into 8 portions in each group. All the samples were tested by microwave digestive - vacuum filtration - automated scanning electron microscopy method. The quantity of diatom recovered and the quality of residue on the membrane were recorded.@*RESULTS@#When the digestion time was set to 60 min, there were statistically significant differences in the number of diatoms recovered at different temperatures (P<0.05). The maximum number of diatoms recovered was (28 797.50±6 009.67) at 140 ℃, and the minimum residue was (0.60±0.28) mg at 180 ℃. When the digestion temperature was set at 140 ℃, there were statistically significant differences in the number of diatoms recovered at different digestion times (P<0.05). The number of diatoms recovered was the highest at 40 min, it was up to (20 650.88±1 950.29), and the residue quality of each group had no statistical significance among different digestion time groups(P>0.05).@*CONCLUSIONS@#The effect of diatom digestion is related to temperature and time. When the digestion temperature was 140 ℃ and the digestion time was 40, 50 and 60 min, it is favorable for diatom test.

Pathway of Diatoms Enter Experimental Rabbits through the Lymphatic System of the Digestive Tract / 法医学杂志

OBJECTIVES@#To study whether diatoms can enter the body through the lymphatic system of the digestive tract.@*METHODS@#Twenty experimental rabbits were divided into the test group and the control group randomly, and intragastric administration was performed with 20 mL water sample from the Pearl River and 20 mL ultrapure water, respectively. After 30 min, lymph, lungs, livers and kidneys were extracted for the diatom test. The concentration, size and type of diatoms were recorded.@*RESULTS@#The concentration of diatoms of the test group was higher than that of the control group (P<0.05). In the test group, Stephanodiscus, Coscinodiscus, Cyclotella, Melosira, Nitzschia, Synedra, Cymbella, and Navicula were detected; in the control group, Stephanodiscus, Coscinodiscus and Cyclotella were detected. The long diameter and the short diameter of diatoms of the test group were higher than those of the control group (P<0.05). In the test group, 1-2 diatoms were detected in 3 lung samples and 2 liver samples, which were Stephanodiscus or Cyclotella, and no diatoms were detected in the kidney samples; in the control group, 1-2 diatoms were detected in 2 lung samples and 3 liver samples, which were Stephanodiscus or Coscinodiscus, and no diatoms were detected in the kidney samples.@*CONCLUSIONS@#Diatoms can enter the body through the lymphatic fluid, which is one of the reasons for the presence of diatoms in tissues and organs of non-drowning cadavers.

Epidemic Characteristics of the Novel Coronavirus Delta Variant in Guangzhou and Grid Crowd Management Based on Public Security Forensic Perspective / 法医学杂志

Abstract： Objective To analyze the first epidemic spread of the novel coronavirus Delta variant in China based on public security forensic perspective, investigate its transmission characteristics, contributing factors, and epidemiologic research experience, and provide a reference for the prevention and control of the epidemic caused by the novel coronavirus variant. Methods Based on the information that public security forensic experts obtained from front-line epidemiologic research, the gender, age, place of residence, transmission route and infectivity of the coronavirus disease 2019 （COVID-19） confirmed cases, asymptomatic infected persons and their close contacts in Guangzhou caused by the novel coronavirus Delta variant were analyzed. The basic reproduction number （R0） during this epidemic in Guangzhou was calculated. Results Among the 153 cases infected with novel coronavirus Delta variant in the epidemic, 63 cases were male and 90 cases were female, their age ranging from 1 to 92 years, with a median age of 49 years. The main route of transmission was close contact, including dining together, co-living, and close contact in the same residential building. There were 31 cases of family clusters, 25 of which were in Liwan District. The epidemic lasted from May 26 to May 29, and the R0 remained above 4.0. After May 30, R0 began to decline and remained below 1.0 from June 7. Conclusion The novel coronavirus Delta variant is highly infectious, the crowd is generally susceptible to infection and family cluster cases are easy to occur. So, it is necessary to precisely prevent and control this strain. Public security forensic experts have both medical literacy and criminal investigation capabilities, they can play a more professional role in epidemic prevention and control.

Effects of Notch signal on the expressions of HIF-α and autophagy- related genes Beclin1, LC3I, LC3II in oxygen-glucose deprivation induced myocardial cell injury / 中国应用生理学杂志

OBJECTIVE@#To investigate the effects of Notch signal on hypoxic induction factor (HIF-1α) and autophagy-associated genes Beclin1, LC3I, LC3II in oxygen-glucose deprivation (OGD) induced myocardial cell injury.@*METHODS@#The OGD model was established using hypoxic culture box and hypoglycemic DMEM medium. The cells were divided into normal control group, OGD group, OGD + NC siRNA group, OGD + Notch1 siRNA group and OGD + HIF-1α siRNA group. Western blot was used to detect the interference effects of HIF-1α siRNA and Notch1 siRNA. The effects of Notch1 siRNA and HIF-1α siRNA on the activity of myocardial cells in OGD model were detected by the CCK-8 assay. The effects of Notch1 siRNA and HIF-1α siRNA on autophage-associated genes Beclin1, LC3I and LC3II expression were detected by Western blot.@*RESULTS@#The results of Western blot showed that HIF-1α siRNA could effectively knock down the expression of HIF-1α in myocardial cells in OGD model, and Notch1 siRNA could effectively knock down the expression of Notch1 and HIF-1α in myocardial cells in OGD model. The result of CCK-8 assay showed that Notch1 siRNA and HIF-1α siRNA reduced the activity of myocardial cells in OGD model, and there was no statistical difference between the two groups. Western blot results showed that Notch1 siRNA and HIF-1α siRNA could reduce the expressions of the autophagy-associated genes Beclin1, LC3I and LC3II, and reduce the ratio of LC3II to LC3I at mRNA level.@*CONCLUSION@#Notch1 plays a role in myocardial protection by regulating the expression of HIF-1α to regulate the autophagy in OGD model cells.

Application of Quantitative Analysis of Diatoms in Lung Tissue for the Diagnosis of Drowning of Experimental Animals / 法医学杂志

Objective To discuss the application value of diatom examination in lung tissue for the forensic diagnosis of drowning. Methods The experimental animals were divided randomly into drowning, postmortem submergence and dying on land group. Diatoms in lung tissue and drowning fluid were analyzed quantitatively by microwave digestion-vacuum filtration-automated scanning electron microscopy diatom examination method. The ratios of content of diatoms in lung tissue and drowning fluid （CL/CD ratio） were recorded. Results The CL/CD ratios of experimental rabbits in the drowning group （5.82±3.50） were much higher than that of postmortem submergence group （0.47±0.35）; the CL/CD ratios of different parts of the lung lobes of experimental pigs in the drowning group were higher than that of postmortem submergence group （P<0.05）; in seawater, brackish water, river fresh water and lake fresh water, the CL/CD ratios of experimental pigs in the drowning group were higher than that of postmortem submergence group （P<0.05）. In animal experiments, all the cases with CL/CD ratio >1.6 were from drowning group. Conclusion CL/CD ratio is an indicator with good application prospects in the diagnosis of drowning.

Research Progress on Determination of Drowning Site / 法医学杂志

The bodies found in water are one of the most common types in forensic practice. The dis-covery site of the body is often not the drowning site. However, the determination of drowning site is vital for the identification of victim. Inorganic particles and planktons, such as granular impurities, diatoms and bacteria, are valuable markers for the diagnosis of drowning. By comparing the granular impurities and planktons in tissues and suspicious drowning mediums, the drowning site can be concluded based on their similarity of types and distribution, which has practical applied value. In this paper, the research progress on determination of drowning site is summarized to provide reference for the peers.

Research Progress of the Correlation between Caveolin and Unexpected Sudden Cardiac Death / 法医学杂志

D ue to the negative autopsy and w ithout cardiac structural abnorm alities, unexpected sudden cardiac death (U SC D ) is alw ays a tough issue for forensic pathological expertise. U SC D m ay be asso-ciated w ith parts of fatal arrhythm ic diseases. T hese arrhythm ic diseases m ay be caused by disorders of cardiac ion channels or channel-related proteins. C aveolin can com bine w ith m ultiple m yocardial ion channel proteins through its scaffolding regions and plays an im portant role in m aintaining the depolar-ization and repolarization of cardiac action potential. W hen the structure and function of caveolin are af-fected by gene m utations or abnorm al protein expression, the functions of the regulated ion channels are correspondingly im paired, w hich leads to the occurrence of m ultiple channelopathies, arrhythm ia or even sudden cardiac death. It is im portant to study the effects of caveolin on the functions of ion channels for exploring the m echanism s of m alignant arrhythm ia and sudden cardiac death.

Molecular epidemiological characteristics and genotype analysis of norovirus in Zhenjiang region / 临床检验杂志

Objective To analyze the molecular epidemiological characteristics and genotype distribution of norovirus in Zhenjiang region during 2015 and 2016.Methods The fecal samples from diarrhea patients in Zhenjiang region were collected,and the expression level of norovirus capsid protein gene was detected by reverse transcription PCR (RT-PCR).The PCR products were validated by gene sequencing.Then,phylogenetic tree was constructed with Mega software,and sequence evolution and genotype were analyzed.Results The positive rate of norovirus infection was 5.30％ (85/1 605).Among them,the detection rates of G Ⅰ genogroup and G Ⅱ genogroup were 0.87％ (14/1 605) and 4.55％ (73/1 605),respectively,and 2 samples were detected both of G Ⅰ and G Ⅱ genogroups.The highest positive rate of G Ⅱ genogroup occurred in adolescent patients aged from 10 to 20 years (17.80％).During 2015,the detection rate of norovirus infection was the highest in January,and then in November and February.During 2016,the detection rate of norovirus infection was the highest in December,and then in March and April.The main genotypes of norovirus in 2015 and 2016 were new G Ⅱ.17 variant (63.89％) and G Ⅱ.4 Sydney_2012 strain (35 ％),respectively.Conclusion The infection of norovirus in Zhenjiang region appears G Ⅱ as main genogroup,adolescent as main patients,November to April of the next year as main epidemic seasons,and G Ⅱ.17 variant and G Ⅱ.4 Sydney_2012 strain as main epidemic genotypes.

Correlation between Genetic Variants and Polymorphism of Caveolin and Sudden Unexplained Death / 法医学杂志

Objective T o explore the genetic variation sites of caveolin (C A V ) and their correlation w ith sudden unexplained death (SU D ).Methods The blood sam ples w ere collected from SU D group (71 cases), coronary artery disease (C A D ) group (62 cases) and control group (60 cases), respectively. T he genom e D N A w ere extracted and sequencing w as perform ed directly by am plifying gene coding region and exon-intron splicing region of CAV1 and CAV3 using PC R . T he type of heritable variation of CVA w as con-firm ed and statistical analysis w as perform ed. Results A total of 4 variation sites that m aybe significa-tive w ere identified in SU D group, and tw o w ere new found w hich w ere CAV1: c.45C>T (T 15T ) and CAV1:c.512G>A (R 171H ), and tw o w ere SN P loci w hich w ere CAV1:c.246C>T (rs35242077) and CAV3:c.99C>T (rs1008642) and had significant difference (P<0.05) in allele and genotype frequencies betw een SU D and control groups. Forem entioned variation sites w ere not found in C A D group. Conclu-sion T he variants of CAV1 and CAV3 m ay be correlated w ith a part of SU D group.

Nine-hole Peg Test and Ten-meter Walk Test for Evaluating Functional Loss in Chinese Charcot-Marie-Tooth Disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The 9-hole peg test (9-HPT) and 10-meter walk test (10-MWT) are commonly used to test finger motor function and walking ability. The aim of this present study was to investigate the efficacy of these tests for evaluating functional loss in Chinese Charcot-Marie-Tooth (CMT) disease.</p><p><b>METHODS</b>Thirty-four Chinese CMT patients (CMT group) from August 2015 to December 2016 were evaluated with 9-HPT, 10-MWT, CMT disease examination score, overall neuropathy limitation scale (ONLS), functional disability score, and Berg Balance Scale (BBS). Thirty-five age- and gender-matched healthy controls (control group) were also included in the study. Student's nonpaired or paired t-test were performed to compare data between two independent or related groups, respectively. The Pearson test was used to examine the correlations between recorded parameters.</p><p><b>RESULTS</b>The mean 9-HPT completion time in the dominant hand of CMT patients was significantly slower than that in the healthy controls (29.60 ± 11.89 s vs. 19.58 ± 3.45 s; t = -4.728, P < 0.001). Women with CMT completed the 9-HPT significantly faster than men with CMT (dominant hand: 24.74 ± 7.93 s vs. 33.01 ± 13.14 s, t = 2.097, P = 0.044). The gait speed of the average self-selected velocity and the average fast-velocity assessed using 10-MWT for CMT patients were significantly slower than those in the control group (1.03 ± 0.18 m/s vs. 1.44 ± 0.17 m/s, t = 9.333, P < 0.001; 1.31 ± 0.30 m/s vs. 1.91 ± 0.25 m/s, t = 8.853, P < 0.001, respectively). There was no difference in gait speed between men and women. Both 9-HPT and 10-MWT were significantly correlated with the ONLS, functional disability score, and BBS (P < 0.05 for all).</p><p><b>CONCLUSION</b>The 9-HPT and 10-MWT might be useful for functional assessment in Chinese patients with CMT.</p>

Correlation between Genetic Variants and Polymorphism of Caveolin and Sudden Unexplained Death / 法医学杂志

OBJECTIVES@#To explore the genetic variation sites of caveolin （CAV） and their correlation with sudden unexplained death （SUD）.@*METHODS@#The blood samples were collected from SUD group （71 cases）, coronary artery disease （CAD） group （62 cases） and control group （60 cases）, respectively. The genome DNA were extracted and sequencing was performed directly by amplifying gene coding region and exon-intron splicing region of CAV1 and CAV3 using PCR. The type of heritable variation of CVA was confirmed and statistical analysis was performed.@*RESULTS@#A total of 4 variation sites that maybe significative were identified in SUD group, and two were newfound which were CAV1： c.45C>T （T15T） and CAV1：c.512G>A （R171H）, and two were SNP loci which were CAV1：c.246C>T （rs35242077） and CAV3：c.99C>T （rs1008642） and had significant difference （P<0.05） in allele and genotype frequencies between SUD and control groups. Forementioned variation sites were not found in CAD group.@*CONCLUSIONS@#The variants of CAV1 and CAV3 may be correlated with a part of SUD group.

Research Progress of the Correlation between Caveolin and Unexpected Sudden Cardiac Death / 法医学杂志

Due to the negative autopsy and without cardiac structural abnormalities, unexpected sudden cardiac death （USCD） is always a tough issue for forensic pathological expertise. USCD may be associated with parts of fatal arrhythmic diseases. These arrhythmic diseases may be caused by disorders of cardiac ion channels or channel-related proteins. Caveolin can combine with multiple myocardial ion channel proteins through its scaffolding regions and plays an important role in maintaining the depolarization and repolarization of cardiac action potential. When the structure and function of caveolin are affected by gene mutations or abnormal protein expression, the functions of the regulated ion channels are correspondingly impaired, which leads to the occurrence of multiple channelopathies, arrhythmia or even sudden cardiac death. It is important to study the effects of caveolin on the functions of ion channels for exploring the mechanisms of malignant arrhythmia and sudden cardiac death.

Relation between partial mechanical injuries and nature of death in high-falling cases: an analysis of 205 cases / 法医学杂志

OBJECTIVE@#To explore the relation between the behavior psychology analysis of partial mechanical injuries and the nature of death in high-falling cases, and provide reference, for such cases.@*METHODS@#Of 311 death victims of high-falling injuries collected from 2008 to 2013, 205 cases were associated with partial mechanical injuries. The characteristics of injury formation, preliminary crime scene traces, fatal injury of high-falling, and text messages were all retrospectively analyzed.@*RESULTS@#According to the investigation of preliminary crime scene traces, fatal injury of high-falling and text message, there were 86 suicide, 24 accident and 95 uncertainty in the 205 cases. According to the behavior psychology analysis of partial mechanical injuries, there were 80 suicide, 11 accident, and 4 homicide in the 95 uncertainty cases.@*CONCLUSION@#The partial mechanical injuries uncertainly caused by high-falling correlate with the manner of high-falling death. According to the behavior psychology analysis of the partial mechanical injuries in high-falling death cases, the presumption of high-falling death is usually accurate

Nerve growth factor for the treatment of spinocerebellar ataxia type 3: an open-label study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Spinocerebellar ataxia type 3 (SCA3) is the most common subtype of SCA worldwide, and runs a slowly progressive and unremitting disease course. There is currently no curable treatment available. Growing evidence has suggested that nerve growth factor (NGF) may have therapeutic effects in neurodegenerative diseases, and possibly also in SCA3. The objective of this study was to test the efficacy of NGF in SCA3 patients.</p><p><b>METHODS</b>We performed an open-label prospective study in genetically confirmed adult (>18 years old) SCA3 patients. NGF was administered by intramuscular injection (18 μg once daily) for 28 days consecutively. All the patients were evaluated at baseline and 2 and 4 weeks after treatment using the Chinese version of the scale for assessment and rating of ataxia (SARA).</p><p><b>RESULTS</b>Twenty-one SCA3 patients (10 men and 11 women, mean age 39.14 ± 7.81 years, mean disease duration 4.14 ± 1.90 years, mean CAG repeats number 77.57 ± 2.27) were enrolled. After 28 days of NGF treatment, the mean total SARA score decreased significantly from a baseline of 8.48 ± 2.40 to 6.30 ± 1.87 (P < 0.001). Subsections SARA scores also showed significant improvements in stance (P = 0.003), speech (P = 0.023), finger chase (P = 0.015), fast alternating hand movements (P = 0.009), and heel-shin slide (P = 0.001).</p><p><b>CONCLUSIONS</b>Our preliminary data suggest that NGF may be effective in treating patients with SCA3.</p>

Relation between Partial Mechanical Injuries and Nature of Death in High-falling Cases：An Analysis of 205 Cases / 法医学杂志

Objective To explore the relation between the behavior psychology analysis of partial me-chanical injuries and the nature of death in high-falling cases, and provide reference, for such cases. Methods Of 311 death victims of high-falling injuries collected from 2008 to 2013, 205 cases were as-sociated with partial mechanical injuries. The characteristics of injury formation, preliminary crime scene traces, fatal injury of high-falling, and text messages were all retrospectively analyzed. Results Accord-ing to the investigation of preliminary crime scene traces, fatal injury of high-falling and text message, there were 86 suicide, 24 accident and 95 uncertainty in the 205 cases. According to the behavior psy-chology analysis of partial mechanical injuries, there were 80 suicide, 11 accident, and 4 homicide in the 95 uncertainty cases. Conclusion The partial mechanical injuries uncertainly caused by high-falling correlate with the manner of high-falling death. According to the behavior psychology analysis of the partial mechanical injuries in high-falling death cases, the presumption of high-falling death is usually accurate.

Investigation on the IL-18 -607A/C and -137C/G on the susceptibility of ischemic stroke

We conducted a case-control study with 322 cases and 322 controls to assess the role of the two common SNPs in the promoter of IL-18 gene. Polymerase chain reaction restriction fragment length of polymorphism [PCR-RFLP] was taken to genotype -607A/C and -137C/G in the promoter of the IL-18 gene. By comparing cases and control subjects, we found that IS cases were more likely to have higher BMI, higher proportion of hypertension, and have higher proportion of smokers and drinkers. We found that IL-18 -607CC genotype [OR=1.70, 95% CI=1.03-2.81] and C allele [OR=1.26, 95% CI=1.01-1.58] were significantly more frequent in IS patients when compared with AA genotype. We did not find significant association between IL-18 -607A/C gene polymorphism and BMI, hypertension, smoking and drinking on the risk of IS. Our study suggests that polymorphisms in IL-18 -607A/C can influence the development of IS, and this gene polymorphism is associated with risk of IS in a Chinese population

Reliability and validity of the Chinese version of the Scale for Assessment and Rating of Ataxia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The Scale for the Assessment and Rating of Ataxia (SARA) was shown to be a reliable and valid measurement for patients with spinocerebellar ataxia (SCA). The Brazilian version and the Japanese version of SARA were favorable for good reliability and validity. This study aimed to translate SARA into Chinese and test its reliability and validity in measurement of cerebellar ataxia.</p><p><b>METHODS</b>SARA was translated into Chinese. A total 39 patients with degeneration cerebellar ataxia were evaluated independently by two neurologists with the Chinese version of SARA. Then the patients were evaluated by one of above neurologists with International Cooperative Ataxia Rating Scale (ICARS). The statistical analyses were performed using SPSS 17.0 for Windows.</p><p><b>RESULTS</b>The Cronbach's alpha coefficient of the Chinese version of SARA was 0.78, which represents a good internal consistence. The correlation coefficient of the Chinese version of SARA scores between the two evaluators was 0.86, illustrating that the inter-rater reliability of Chinese version of SARA was good. The correlation coefficient between the Chinese version of SARA and ICARS was 0.91, illustrating that the criterion validity of Chinese version of SARA was not bad.</p><p><b>CONCLUSIONS</b>The Chinese version of SARA is reliable and effective for the assessment of degeneration cerebellar ataxia. Compared with ICARS, the evaluation of Chinese version of SARA is more objective, the assessment time is shortened, and the maneuverability is better.</p>

Estimation of postmortem interval by detecting thickness of cornea using ultrasonic method / 法医学杂志

OBJECTIVE@#To explore the postmortem changes of cornea thickness measured by ultrasonic pachymetry.@*METHODS@#Eleven rabbits were randomly divided into two groups: one group with intact corneal epithelium and another group without intact corneal epithelium. In the later group, the corneal epithelium of the rabbit was scraped using mechanical elimination method. The corneal thickness was monitored continuously by ultrasonic pachymetry at several postmortem interval points in rabbits of the two groups. The changes of corneal thickness and postmortem interval were explored by relative regression analysis.@*RESULTS@#The thickness of the cornea showed a strong non-linear correlation with the postmortem interval in the group with intact corneal epithelium. The group with intact corneal epithelium showed the correlation coefficient 0.922 and the group without intact corneal epithelium showed the correlation coefficient 0.822, respectively.@*CONCLUSION@#The corneal thickness measured by ultrasonic pachymetry shows a potential value for estimating early postmortem interval. The intact corneal epithelium is a crucial factor for the measurement of cornea thickness by ultrasonic pachymetry.