Research Progress on Postmortem Changes of Computed Tomography Imaging Characteristics on Corpses

Abstract

Postmortem changes on corpses appear immediately after death, and can transform the original structure characteristics of the corpse to different degrees as well as show specific changes on computed tomography （CT） images, sometimes with false positives and false negatives, influencing the identification of injuries or diseases. This paper systematically summarizes the postmortem changes of computed tomography imaging characteristics on corpses, to further expand the application of virtopsy in the practices of forensic pathology identification, and provide reference for the identification of injuries, diseases and changes after normal death.

Piperine, a functional food alkaloid, exhibits inhibitory potential against TNBS-induced colitis via the inhibition of IκB-α/NF-κB and induces tight junction protein (claudin-1, occludin, and ZO-1) signaling pathway in experimental mice

BACKGROUND

Inflammatory bowel disease is a chronic immunoinflammatory disease of the gastrointestinal tract. Piperine, an alkaloid, has been reported to possess antioxidant, anti-inflammatory, antiapoptotic, and antiulcer potential.

AIM

To elucidate the plausible mechanisms of action of piperine on experimental trinitrobenzenesufonic acid (TNBS)-induced colitis by assessing various biochemical, molecular, histological, and ultrastructural modifications.

METHODS

Colitis was induced in male Sprague-Dawley rats via intrarectal instillation of TNBS. Then, the rats were treated with piperine (10, 20, and 40 mg/kg, p.o.) for 14 days.

RESULTS

TNBS induced significant (p < 0.05) colonic damage, which was assessed by disease activity index, macroscopic score, and stool consistency. The administration of piperine (20 and 40 mg/kg) significantly inhibited (p < 0.05) these damages. Treatments with piperine (20 and 40 mg/kg) notably inhibited (p < 0.05) the TNBS-induced elevation of oxido-nitrosative stress (superoxide dismutase, glutathione, malondialdehyde, and nitric oxide), 5-hydroxytryptamine, and hydroxyproline content in the colon. Furthermore, colonic inducible nitric oxide synthase (iNOs), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6, interferon-gamma, and cyclooxygenase-2 (COX-2) messenger RNA (mRNA) expressions were upregulated after TNBS instillation and piperine (20 and 40 mg/kg) significantly attenuated (p < 0.05) these elevated mRNA expressions. TNBS decreased the expressions of tight junction (TJ) protein (claudin-1, occludin, and zonula occludens-1 (ZO-1)) and increased the expressions of proapoptotic (caspase-1) protein. These expressions were markedly inhibited (p < 0.05) by piperine treatment. Histological and ultrastructural studies of transmission electron microscopy suggested that piperine significantly ameliorated (p < 0.05) TNBS-induced colonic aberrations.

CONCLUSION

Piperine ameliorated the progression of TNBS-induced colitis by modulating the nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha/nuclear factor-kappa B signaling pathway, thus inhibiting the overexpression of proinflammatory cytokines (TNF-α and IL's), COX-2, iNOs, oxido-nitrosative stress, and proapoptotic proteins (caspase-1) that may improve the expression of TJ protein (claudin-1, occludin, and ZO-1).

Dorsal-ventral patterned neural cyst from human pluripotent stem cells in a neurogenic niche

Despite its importance in central nervous system development, development of the human neural tube (NT) remains poorly understood, given the challenges of studying human embryos, and the developmental divergence between humans and animal models. We report a human NT development model, in which NT-like tissues, neuroepithelial (NE) cysts, are generated in a bioengineered neurogenic environment through self-organization of human pluripotent stem cells (hPSCs). NE cysts correspond to the neural plate in the dorsal ectoderm and have a default dorsal identity. Dorsal-ventral (DV) patterning of NE cysts is achieved using retinoic acid and/or sonic hedgehog and features sequential emergence of the ventral floor plate, P3, and pMN domains in discrete, adjacent regions and a dorsal territory progressively restricted to the opposite dorsal pole. This hPSC-based, DV patterned NE cyst system will be useful for understanding the self-organizing principles that guide NT patterning and for investigations of neural development and neural disease.

Quantitative Expression of RNA from Frozen Organs and Formaldehyde-fixed and Paraffin-embedded Tissues

Abstract

Objective Quantitative analysis and comparison of the expression of ribonucleic acid （RNA） from frozen organs and formaldehyde-fixed and paraffin-embedded （FFPE） tissues. Methods Frozen specimens of human brain, myocardium and liver tissues as well as FFPE samples at different postmortem intervals were collected and mass concentration of RNA was extracted and detected. Reverse transcription-quantitative polymerase chain reaction （RT-qPCR） technology was used to analyze the amplification efficiency and relative expression of each RNA marker. Results The mass concentration and integrity of RNA extracted from FFPE samples were relatively low compared with frozen specimens. The amplification efficiency of RNA markers was related with RNA species and the length of amplification products. Among them, glyceraldehyde-3-phosphate dehydrogenase （GAPDH） and β-actin （ACTB） with relatively long amplification products failed to achieve optimal amplification efficiency, whereas 5S ribosomal RNA （5S rRNA） achieved ideal amplification efficiency and showed quite stable expression across various tissues, therefore it was chosen as internal reference marker. The expression quantity of GAPDH and ACTB in frozen specimens with longer postmortem intervals and in FFPE samples with relatively long amplification products was decreased. The expressions of tissue-specific microRNAs （miRNAs）, GAPDH and ACTB with relatively short amplification products had consistency in the same tissues and FFPE samples. Conclusion Through standardizing the RT-qPCR experiment, selecting the appropriate RNA marker and designing primers of appropriate product length, RNA expression levels of FFPE samples can be accurately quantified.

Genome-wide identification and comparison of mRNAs, lncRNAs and circRNAs in porcine intramuscular, subcutaneous, retroperitoneal and mesenteric adipose tissues

Many types of RNAs, including messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), play crucial roles in regulating fat cell differentiation and tissue development. However, the expression profiles of these RNAs in different adipose tissues are still largely unknown. To shed light on this issue, we performed a transcriptome analysis of mRNAs, lncRNAs and circRNAs obtained from intramuscular adipose tissue, subcutaneous adipose tissue, retroperitoneal adipose tissue and mesenteric adipose tissue of Chinese Erhualian pigs. A number of differentially expressed mRNAs, lncRNAs and circRNAs were identified among the four adipose tissues. Tissue-specific analysis indicated that circRNAs exhibited the highest tissue specificity among mRNAs, lncRNAs and circRNAs, whereas intramuscular adipose tissue had the most tissue-specific genes among the four adipose tissues. Gene Ontology analysis showed that differentially expressed mRNAs among groups were involved mainly in lipid metabolism and immune inflammatory response processes. Furthermore, the co-expression network construction of mRNAs-lncRNAs revealed that several important lncRNAs, such as MSTRG.426159 and MSTRG.604206, might associate with lipid metabolic process. Taken together, these data provide a genome-wide resource of mRNAs, lncRNAs and circRNAs potentially involved in porcine fat metabolism, thus improving understanding of their function in diverse adipose tissues.

[Analysis of influencing factors and causes of death in elderly residents with non-alcoholic fatty liver disease]

Objective: To understand and analyze the incidence rate, risk factors, independent risk factors and the causes of death in elderly population with non-alcoholic fatty liver disease (NAFLD). Furthermore, analyze the relationship between metabolic syndrome (MS) and mortality rate in patients with NAFLD to provide evidence for the prevention and control of NAFLD in the elderly population. Methods: A total of 7 619 elderly people aged over 60 years, and local household registered in Kunshan city, Jiangsu province in 2016 were included as subjects to analyze the incidence rate, influencing factors and causes of death in patients with NAFLD and the relationship between MS and mortality rate in patients with NAFLD. According to different data, using Kruskal-Wallis H test, analysis of variance, t-test, chi-square test or logistic regression analysis were performed. Results: The prevalence of NAFLD was14.10% (1 074/7 619) among the elderly over 60 years in Kunshan city, Jiangsu province in 2016, and the female prevalence rate was significantly higher than that of males (P < 0.05). When the body mass index (BMI) was < 32 (kg/m(2)), the prevalence of NAFLD increased with the increase of BMI index. When BMI was 18.5-23.9 kg/m2, 24-27.9 kg/m(2) and > 32 kg/m(2), the prevalence of NAFLD was significantly higher in females than males (P < 0.05). There was no significant difference in prevalence between males and females with BMI <18.5 kg/m(2) and 28~31.9 kg/m(2) (P > 0.05). BMI gradually decreased (P < 0.05) with the increase of age, and the incidence of NAFLD showed a downward trend (P < 0.05). An independent risk factors for NAFLD (P < 0.01) were gender (OR = 0.616), age (OR = 0.970), waist circumference (OR = 1.065), triglycerides (OR = 1.162), BMI (OR = 1.238), and diastolic blood pressure (OR = 1.012). The probability of NAFLD combined with three and four kinds of MS was significantly higher than control group (P < 0.05). Subjects' mortality rate during the follow-up period was 1.94%, 2.23% in the NAFLD group, and 1.89% in the control group. Average life expectancy was 75.58 years in NAFLD group and 78.68 years in the control group. All deaths in NAFLD groups were associated with MS, and 70.83% combined with three or more MS. The primary cause of death in NAFLD group was tumors (37.5%), followed by cardiovascular disease (16.67%) and three cases died directly from MS. Conclusion: The prevalence of NAFLD in the elderly population in Kunshan city, Jiangsu province is relatively low, which may be associated with local diet and high-intensity workouts. MS disorders represented by obesity and diabetes mellitus are closely associated to the onset of NAFLD. Obesity is the most important risk factor for the incidence of NAFLD in the local elderly population over 60 years old. However, the risk of NAFLD should not be neglected in people with normal BMI, especially in aged women, and the weight control should be the most important means to prevent and control NAFLD. NAFLD may increase mortality rate and reduce life expectancy in the elderly population. The main reason to cause death in the elderly with NAFLD is cardiovascular disease and malignant tumors. Simultaneously, multiple MS development may increase the death rate in elderly with NAFLD.

[Effects of budesonide aerosol inhalation on the immunological functions of peripheral dendritic cells in patients with allergic rhinitis]

Objective: To investigate the immunologic functional changes of peripheral dendritic cells (DC) in patients with allergic rhinitis (AR) during the treatment by budesonide aerosol inhalation.Method:25 patients with moderate to severe persistent AR were concluded in current study, and they were given budesonide aerosol inhalation for 8 weeks. AR related nasal symptom scores and indices, peripheral DC counts and percentages as well as their activation before and 4 weeks, 8 weeks after treatment were determined.Result:There were significant decrease in nasal symptom scores, eosinophils, AR specific IgE antibodies after 4 and 8 weeks of treatment. The overall clinical efficiency reached 88% at the end of the treatment. Peripheral DC counts and DC/PBMC decreased in comparison with the levels of pre-treatment (P<0.05). Compared with the levels before treatment, DC activation markers CD86 and CD80 reduced to various extent, while glucocorticoid-induced leucine zipper (GILZ) positive cells gradually elevated (P<0.05). In the DC secreted IL-10 decreased against the treatment duration, while IFN-γ from DC conditioned T cells statistically increased after treatment (P<0.05). Conclusion:Budesonide suppressed DC activation and maturation, which might redirect DC-involved Th2 response, in turn alleviating the AR symptoms.

[Outcomes of 27G(+) transconjunctival sutureless vitrectomy for posterior segment disease]

Objective: To report the clinical outcomes and safety profile of 27G(+) transconjunctival sutureless vitrectomy (TSV) in eyes with posterior segment disease. Methods: Prospective, interventional case series. Eyes undergoing 27G(+) TSV for a vitreoretinal surgery indication were included from Dec 2015 to Mar 2016. Change in visual acuity and occurrence of intraoperative and postoperative complications with minimum follow-up of 6 weeks were recorded. Results: Eighty-three eyes met the inclusion criteria. Surgical indications included epiretinal membrane (n=27), proliferative diabetic retinopathy (n=17), full-thickness macular hole (n=11), rhegmatogenous retinal detachment with or without proliferative vitreoretinopathy (PVR) (n=8), vitreous hemorrhage(n=7), vitreous opacities (n=7), diabetic macular edema non-response to anti-VEGF agents(n=4), intraocular lens or cataract nucleus dropped into vitreous cavity (n=2). Mean follow-up was 19 weeks (range 6-34 weeks). Visual acuity improved in all cases. The cutter incarcerated with trocar in a vitreous hemorrhage case. There were no other intraoperative complications and no case required sutured at the conclusion of surgery. Postoperative complications included transient ocular hypertension in 2 eyes (2.4%) and transient hypotony in 1 eye (1.2%). No cases of postoperative endophthalmitis, sclerotomy related retinal tears, or choroidal detachments were encountered in the follow-up period. Conclusion: The 27G(+) TSV was effective and safe for varied surgical indications with low rates of intraoperative and postoperative complications. (Chin J Ophthalmol, 2018, 54:918-922).

[Suture under tension across cartilage in the application of the crooked nose surgery]

Objective:Observing the effect of maintain tension across suture between cartilages to fix new nasal structure on balance the asymmetric strength of the two sides of the cartilage and the recurrence of the postoperative crooked nose.Method:A L-shaped struct made of the nasal septum cartilage were fixed to maintain tension across structure between cartilage during rhinoplasty in 39 patients with crooked nasal deformity. Of 21 cases were type I deviation, of 12 cases were C-shaped deviation,and of 6 cases were S-shaped deviation.Result:A 1-5 years follow-up were performed. The effects were divided into three degrees: 30 cases excellent (76.92%), 6 cases good (15.38%) and 3 cases acceptable (7.69%).The rate of excellent and good was 92.31%(36/39). The type I improvement rate was 80.3%,the rate of type C was 83.6% and the improvement rate of type S was 84.1%,the overall improvement rate was about 81.9%.Conclusion:Suture under tension across cartilage can fix reconstruction of nasal structure effectively,improve the postoperative effect, reduce recurrence of crooked nose. The operation is simple and is an essential part of the nasal deformity correction technique.

[Reconstruction of nasal defects of multiple subunits with lateral nasal artery pedicled nasolabial flap]

Objective:To evaluate the effectiveness of the lateral nasal artery pedicled nasolabial flap for reconstruction of nasal defects of multiple subunits. Method:From September 2014 to April 2016, 30 cases of nasal defects in multiple subunits repaired with the lateral nasal artery pedicled nasolabial flap were retrospectively analysed. Result:All flaps survived. Incision at donor and accepted sites healed by first intention. Two patients had mild venous stasis 24 hours after operation and can alleviated spontaneously. Flap revision was performed in 25 cases after 3-6 months. Twentythree cases were followed up 3-12 months. All patients achieved satisfactory results in nasal appearance. Conclusion:The lateral nasal artery pedicled nasolabial flap can reconstruct the nasal defects of multiple subunits, and the texture, color or thickness are similar to the surrounding skin.It is one of the effective methods to repair multiple subunits of nasal defects.

Development and antimicrobial application of plantaricin BM-1 incorporating a PVDC film on fresh pork meat during cold storage

AIMS

The aim of this study was to develop a plantaricin BM-1, a typical IIa bacteriocin produced by Lactocacillus plantarumBM-1, for active polyvinylidene chloride (PVDC) films and to determine the antimicrobial effect of plantaricin BM-1 incorporated into a PVDC film on fresh pork during 7 days of storage at 4°C.

METHODS AND RESULTS

Plantaricin BM-1 solutions (20 480 AU ml^-1 ) that absorbed into the PVDC film increased gradually and reached maximum volumes during exposure for up to 20 h. When soaked in water, the released amount of plantaricin BM-1 from the active PVDC film reached a maximum at 20 h. The plantaricin BM-1 active PVDC film had an obvious antilisterial effect in culture medium and fresh pork inoculated with Listeria monocytogenes. Furthermore, plantaricin BM-1-incorporated PVDC film was also significantly (P < 0·01) reduced to aerobic counts of approximately 1·5 log₁₀ CFU per g after 7 days of storage at 4°C in pork meat, and the pH and total volatile basic nitrogen of pork meat were significantly (P < 0·01, P < 0·05) lower than those of the control.

CONCLUSION

Plantaricin BM-1 active film has an excellent effect to prolong the shelf life of pork meat during cold storage.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study suggest a potential application of bacteriocin active film on meat preservation.

Precise tuning of single molecule conductance in an electrochemical environment

Tuning of molecular conductance in a liquid environment is a hot topic in molecular electronics. In this article, we explore a new concept where the Fermi level positions of the metallic ends are varied simply by modifying the electroactive salt concentration in solution. We rely on the electrochemical scanning tunneling microscope break junction method that allows the construction in solution of copper atomic contacts that can be then bridged by single molecules. The experimental conductance evolution is first confronted with an analytical formulation that allows the deduction of the molecule's LUMO position and electronic coupling factors. These parameters are in close agreement with those obtained by independent DFT calculations.

Soluble TREM2 and biomarkers of central and peripheral inflammation in neurodegenerative disease

Alzheimer's disease (AD) has been genetically and pathologically associated with neuroinflammation. Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial receptor involved in innate immunity. TREM2 rare protein coding genetic variants have been linked to AD. A soluble TREM2 (sTREM2) cleavage product is elevated in AD. It is unclear whether there is a relationship between elevated sTREM2 and markers of inflammation. The hypothesis of this investigation was that central and peripheral inflammation play a role in sTREM2 levels in AD. A consistent association of peripheral or central markers of inflammation and CSF sTREM2 levels was not found, suggesting a limited impact of general inflammation on sTREM2 levels. An association between peripheral sTREM2 levels and CSF sTREM2, as well as an association between CSF sTREM2 and a marker of blood brain barrier integrity, was observed in AD, suggesting a potential role of peripheral TREM2 in central TREM2 biology.

Development and Validation of a Natural Language Processing Tool to Identify Patients Treated for Pneumonia across VA Emergency Departments

BACKGROUND

Identifying pneumonia using diagnosis codes alone may be insufficient for research on clinical decision making. Natural language processing (NLP) may enable the inclusion of cases missed by diagnosis codes.

OBJECTIVES

This article (1) develops a NLP tool that identifies the clinical assertion of pneumonia from physician emergency department (ED) notes, and (2) compares classification methods using diagnosis codes versus NLP against a gold standard of manual chart review to identify patients initially treated for pneumonia.

METHODS

Among a national population of ED visits occurring between 2006 and 2012 across the Veterans Affairs health system, we extracted 811 physician documents containing search terms for pneumonia for training, and 100 random documents for validation. Two reviewers annotated span- and document-level classifications of the clinical assertion of pneumonia. An NLP tool using a support vector machine was trained on the enriched documents. We extracted diagnosis codes assigned in the ED and upon hospital discharge and calculated performance characteristics for diagnosis codes, NLP, and NLP plus diagnosis codes against manual review in training and validation sets.

RESULTS

Among the training documents, 51% contained clinical assertions of pneumonia; in the validation set, 9% were classified with pneumonia, of which 100% contained pneumonia search terms. After enriching with search terms, the NLP system alone demonstrated a recall/sensitivity of 0.72 (training) and 0.55 (validation), and a precision/positive predictive value (PPV) of 0.89 (training) and 0.71 (validation). ED-assigned diagnostic codes demonstrated lower recall/sensitivity (0.48 and 0.44) but higher precision/PPV (0.95 in training, 1.0 in validation); the NLP system identified more "possible-treated" cases than diagnostic coding. An approach combining NLP and ED-assigned diagnostic coding classification achieved the best performance (sensitivity 0.89 and PPV 0.80).

CONCLUSION

System-wide application of NLP to clinical text can increase capture of initial diagnostic hypotheses, an important inclusion when studying diagnosis and clinical decision-making under uncertainty.

[Reconstruction of Vehicle-human Crash Accident and Injury Analysis Based on 3D Laser Scanning, Multi-rigid-body Reconstruction and Optimized Genetic Algorithm]

OBJECTIVES

To reconstruct a vehicle-bicycle-cyclist crash accident and analyse the injuries using 3D laser scanning technology, multi-rigid-body dynamics and optimized genetic algorithm, and to provide biomechanical basis for the forensic identification of death cause.

METHODS

The vehicle was measured by 3D laser scanning technology. The multi-rigid-body models of cyclist, bicycle and vehicle were developed based on the measurements. The value range of optimal variables was set. A multi-objective genetic algorithm and the nondominated sorting genetic algorithm were used to find the optimal solutions, which were compared to the record of the surveillance video around the accident scene.

RESULTS

The reconstruction result of laser scanning on vehicle was satisfactory. In the optimal solutions found by optimization method of genetic algorithm, the dynamical behaviours of dummy, bicycle and vehicle corresponded to that recorded by the surveillance video. The injury parameters of dummy were consistent with the situation and position of the real injuries on the cyclist in accident.

CONCLUSIONS

The motion status before accident, damage process by crash and mechanical analysis on the injury of the victim can be reconstructed using 3D laser scanning technology, multi-rigid-body dynamics and optimized genetic algorithm, which have application value in the identification of injury manner and analysis of death cause in traffic accidents.

Glucagon-Like Peptide-2 Improve Intestinal Mucosal Barrier Function in Aged Rats

Glucagon-like peptide-2 (GLP-2) plays a major role in repairing impaired intestinal mucosa, but its mechanism in the improvement of intestinal barrier function during the aging process remains unclear. In this study, 26-month-old male Sprague-Dawley rats were randomized to control group and GLP-2 group treated with a dose of 250 μg•kg-1•d-1 by intraperitoneal injection. After 14 days of treatment, intestinal mucosal morphometric changes were observed by light microscopy and transmission electron microscopy (TEM). Small intestinal permeability was evaluated by fluorescein isothiocyanate (FITC)-labeled dextran. The mRNA and protein expression of Zonula Occludens-1 (ZO-1), occludin, claudin-1 and the GLP-2 receptor (GLP-2R) were detected by Real-time PCR and Western blot. Our results showed that GLP-2 administration significantly improved the age-related atrophy of intestinal mucosa and villi and increased small intestinal permeability. The mRNA and protein expression of ZO-1and occludin in ileum were up regulated in the GLP-2-treated old rats. In addition, the serum GLP-2 levels were negatively correlated with small intestinal permeability measured by FITC-dextran levels (r=-0.610, P<0.01). Taking all these data together, it is concluded that GLP-2 improved small intestinal epithelial barrier function in aged rats mainly by facilitating intestinal mucosa growth, alleviating the increased small intestinal permeability and increasing ZO-1 and occludin expression. Our observations provide evidence for the clinical significance of GLP-2 in preventing the intestinal epithelial barrier dysfunction during aging.