Postmortem Liver Samples Research Articles

Tissue specific responses to oxidative fuel source preference during heat stress in lactating dairy cows

Prolonged exposure to high environmental temperatures results in an accumulated heat load that induces a heat stress (HS) response in dairy cattle. Heat stress compromises dairy farm profitability by reducing milk yield, altering milk composition, and hindering reproductive performance. The ability to alternate between carbohydrate and lipid sources for energy production is termed metabolic flexibility (Met Flex). The objective of this study was to evaluate the Met Flex of mammary, muscle, and liver tissue in lactating dairy cows under HS and thermoneutral (TN) conditions. Sixteen Holstein cows were assigned to 1 of 2 treatment groups: pair feeding in a TN environment (PFTN) or HS. All cows experienced a 4 d TN period with ad libitum intake followed by a 4 d treatment period. Heat stress cows were exposed to a temperature humidity index (THI) ranging from 76 to 80 and the PFTN cows were exposed to a THI of 64. Milk production and health data were recorded twice daily. Semitendinosus biopsies were obtained on d 4 of each period and post-mortem mammary and liver samples were obtained on d 4 of period 2. All tissue samples were assayed for Met Flex. Activity of mitochondrial (Mit) enzymes were assessed in skeletal muscle only. Four d of HS decreased milk yield, altered milk composition, and increased respiration rate and rectal temperatures. No differences in Met Flex were observed in mammary or liver tissue during period 2. However, HS, but not PFTN conditions, lowered Met Flex of skeletal muscle by 18.3% when compared with TN ad libitum feed intake conditions of period 1. No treatment differences were observed in skeletal muscle Mit enzyme activity indicating the decrease in Met Flex occurred independently of changes in Mit function. The reduction in Met Flex of skeletal muscle during HS may contribute to reduced milk yield and warrants further investigation.

Searching for homozygous haplotype deficiency in Manech Tête Rousse dairy sheep revealed a nonsense variant in the MMUT gene affecting newborn lamb viability

BackgroundRecessive deleterious variants are known to segregate in livestock populations, as in humans, and some may be lethal in the homozygous state.ResultsWe used phased 50 k single nucleotide polymorphism (SNP) genotypes and pedigree data to scan the genome of 6845 Manech Tête Rousse dairy sheep to search for deficiency in homozygous haplotypes (DHH). Five Manech Tête Rousse deficient homozygous haplotypes (MTRDHH1 to 5) were identified, with a homozygous deficiency ranging from 84 to 100%. These haplotypes are located on Ovis aries chromosome (OAR)1 (MTRDHH2 and 3), OAR10 (MTRDHH4), OAR13 (MTRDHH5), and OAR20 (MTRDHH1), and have carrier frequencies ranging from 7.8 to 16.6%. When comparing at-risk matings between DHH carriers to safe matings between non-carriers, two DHH (MTRDHH1 and 2) were linked with decreased insemination success and/or increased stillbirth incidence. We investigated the MTRDHH1 haplotype, which substantially increased stillbirth rate, and identified a single nucleotide variant (SNV) inducing a premature stop codon (p.Gln409*) in the methylmalonyl-CoA mutase (MMUT) gene by using a whole-genome sequencing approach. We generated homozygous lambs for the MMUT mutation by at-risk mating between heterozygous carriers, and most of them died within the first 24 h after birth without any obvious clinical symptoms. Reverse transcriptase-qPCR and western blotting on post-mortem liver and kidney biological samples showed a decreased expression of MMUT mRNA in the liver and absence of a full-length MMUT protein in the mutant homozygous lambs.ConclusionsWe identified five homozygous deficient haplotypes that are likely to harbor five independent deleterious recessive variants in sheep. One of these was detected in the MMUT gene, which is associated with lamb lethality in the homozygous state. A specific management of these haplotypes/variants in the MTR dairy sheep selection program would help enhance the overall fertility and lamb survival.

Immunoassay testing forbarbiturates using alternative matrices inpostmortem tissues from cats anddogs.

The barbiturate drug pentobarbital is commonly used by veterinarians for the euthanasia of domestic animals. During the veterinary forensic autopsy, it is sometimes necessary to determine whether the animal was chemically euthanized with pentobarbital. The use of a human immunochromatographic test for barbiturate screening utilizing dog or cat urine has been previously validated; however, the use of alternative matrices for this purpose is yet to be explored when urine is not available. Postmortem heart, liver, spleen, skeletal muscle, blood and/or urine samples from 20 dogs and 26 cats with a reported chemical euthanasia status were processed using two different methods, bead homogenization and sonication, and screened for barbiturates using a human immunochromatographic test. There was 100% agreement of the immunochromatographic test results using the sonication method with the reported euthanasia status of both dogs and cats. Using the bead homogenization method, agreement with the reported euthanasia status was 93.3% and 96.7% for dogs and cats, respectively, due to invalid test results from four dog and two cat samples. A subset of liver samples (10 canine and 10 feline) was analyzed via gas chromatography-mass spectrometry, and there was 100% agreement between the immunochromatographic test results and gas chromatography-mass spectrometry results for both cats and dogs. Overall, our results support the use of a variety of alternative matrices for barbiturate screening in cats and dogs.

Fatalities Involving Khat in Jazan, Saudi Arabia, 2018 to 2021.

Interpreting fatalities involving khat is challenging due to a lack of data on cathinone and cathine reference concentrations in postmortem tissues. This study investigated the autopsy findings and toxicological results of fatalities involving khat in Saudi Arabia's Jazan region from 1 January 2018 to 31 December 2021. All confirmed cathine and cathinone results in postmortem blood, urine, brain, liver, kidney, and stomach samples were recorded and analyzed. Autopsy findings and the manner and cause of death of the deceased were assessed. Saudi Arabia's Forensic Medicine Center investigated 651 fatality cases over four years. Thirty postmortem samples were positive for khat's active constituents, cathinone and cathine. The percentage of fatalities involving khat was 3% in 2018 and 2019 and increased from 4% in 2020 to 9% in 2021, when compared with all fatal cases. They were all males ranging in age from 23 to 45. Firearm injuries (10 cases), hanging (7 cases), road traffic accident (2 cases), head injury (2 cases), stab wounds (2 cases), poisoning (2 cases), unknown (2 cases), ischemic heart disease (1 case), brain tumor (1 case), and choking (1 case) were responsible for the deaths. In total, 57% of the postmortem samples tested positive for khat only, while 43% tested positive for khat with other drugs. Amphetamine is the drug most frequently involved. The average cathinone and cathine concentrations were 85 and 486 ng/mL in the blood, 69 and 682 ng/mL in the brain, 64 and 635 ng/mL in the liver, and 43 and 758 ng/mL in the kidneys, respectively. The 10th-90th percentiles of blood concentrations of cathinone and cathine were 18-218 ng/mL and 222-843 ng/mL, respectively. These findings show that 90% of fatalities involving khat had cathinone concentrations greater than 18 ng/mL and cathine concentrations greater than 222 ng/mL. According to the cause of death, homicide was the most common fatality involving khat alone (77%). More research is required, especially toxicological and autopsy findings, to determine the involvement of khat in crimes and fatalities. This study may help forensic scientists and toxicologists investigate fatalities involving khat.

Steatosis and Steatohepatitis in Autopsy Specimens of Liver

Background: Liver is the site of many diseases, many of which become symptomatic while some are diagnosed only on autopsy. Involvement of liver is secondary to cardiac, metabolic, social problem like alcoholism, drug toxicity, herbal remedies and environmental exposures. Objectives: This study aims at finding the frequency of steatosis and steatohepatitis in autopsy specimens of liver. Methods: This was a descriptive cross-sectional study carried out at the Department of Pathology, Dhaka Medical College, Dhaka over a period of 2011-2012. Liver samples of postmortem cases from the Department of Forensic Medicine, Dhaka Medical College and autopsy samples of liver received at the Department of Pathology, Dhaka Medical College, sent from different parts of Bangladesh via postal service for histopathological examination were included in this study. Result: Satisfactory liver tissue samples for histological evaluation were available in 200 autopsy specimens (155 male and 45 female) with a mean age of 39.50±14.76 years. Out of 200 cases, the most common lesion was steatosis in 35(17.50%) cases. Steatosis mild, moderate and severe were found in 20(10%) cases, 9(4.50%) cases and 6(3.0%) cases respectively. Steatohepatitis was found in 16(8.0%) cases. Steatohepatitis with fibrous portal expansion, steatohepatitis with bridging fibrosis and steatohepatitis with cirrhosis were detected in 7(3.5%), 6(3%) and 3(1.5%) cases respectively. Conclusion: A high prevalence of steatosis and steatohepatitis was detected in postmortem liver samples of Bangladesh. Since both diseases can have serious clinical consequences, they should be considered as an important threat to the health of the general population of our country.

Evidence of SARS-CoV-2 infection in postmortem lung, kidney, and liver samples, revealing cellular targets involved in COVID-19 pathogenesis

There is an urgent need to understand severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-host interactions involved in virus spread and pathogenesis, which might contribute to the identification of new therapeutic targets. In this study, we investigated the presence of SARS-CoV-2 in postmortem lung, kidney, and liver samples of patients who died with coronavirus disease (COVID-19) and its relationship with host factors involved in virus spread and pathogenesis, using microscopy-based methods. The cases analyzed showed advanced stages of diffuse acute alveolar damage and fibrosis. We identified the SARS-CoV-2 nucleocapsid (NC) in a variety of cells, colocalizing with mitochondrial proteins, lipid droplets (LDs), and key host proteins that have been implicated in inflammation, tissue repair, and the SARS-CoV-2 life cycle (vimentin, NLRP3, fibronectin, LC3B, DDX3X, and PPARγ), pointing to vimentin and LDs as platforms involved not only in the viral life cycle but also in inflammation and pathogenesis. SARS-CoV-2 isolated from a patient´s nasal swab was grown in cell culture and used to infect hamsters. Target cells identified in human tissue samples included lung epithelial and endothelial cells; lipogenic fibroblast-like cells (FLCs) showing features of lipofibroblasts such as activated PPARγ signaling and LDs; lung FLCs expressing fibronectin and vimentin and macrophages, both with evidence of NLRP3- and IL1β-induced responses; regulatory cells expressing immune-checkpoint proteins involved in lung repair responses and contributing to inflammatory responses in the lung; CD34+ liver endothelial cells and hepatocytes expressing vimentin; renal interstitial cells; and the juxtaglomerular apparatus. This suggests that SARS-CoV-2 may directly interfere with critical lung, renal, and liver functions involved in COVID-19-pathogenesis.

Genetic resistance to Campylobacter coli and Campylobacter jejuni in wild boar (Sus scrofa L.)

We studied the genetic resistance to Campylobacter coli and Campylobacter jejuni in wild boar using both STR analysis and genome-wide association studies (GWAS). A total of 60 wild boars hunted in Tuscany (Italy) during the 2018/2019 hunting season were analyzed and genotyped. During postmortem operations, fecal swabs, liver samples and kidneys were collected. Two groups of animals were considered for the statistical analysis: 28 Campylobacter positive (22 for C. coli and 6 for C. jejuni) and 32 Campylobacter negative. Regarding STR analysis, 15 markers belonging to a marker panel validated by the International Society of Animal Genetics (ISAG) for swine were used: for each marker, alleles and genotype frequencies between the two groups of animals were compared using the Chi-square test and Fisher’s exact tests. To analyze the genetic variability within groups, the following parameters were computed: molecular coancestry coefficients (fij), kinship distance (Dk), inbreeding coefficient (Fi), and genetic similarities (GS). The internal relatedness (IR) was also calculated, and ANOVA was used to verify the relationships between IR and Campylobacter groups. For GWAS, the Geneseek Genomic Profiler Porcine HD (70 k), containing 62,330 SNPs, was used. No differences in the internal relatedness (IR) were observed between the two groups (F = 5.64, P = 0.065) and no significant association between STRs and SNPs and Campylobacter positivity was observed. Although genetic resistance to bacterial diseases is often regulated by multiple genes controlling different processes of the host–pathogen interaction, in our studies no candidate genes that could be directly or indirectly involved in the development of the disease were identified.

Postmortem mitochondrial membrane permeability transition assessment of apoptotic cell death in brain and liver of insulin resistant, ovariectomised rats.

The adverse alterations in mitochondrial functions can affect neuronal function negatively, as they play a crucial role in neuronal plasticity and death. Direct measurements of mitochondrial activity, including membrane potential and ATP production, are not easily achieved in post-mortem brain and liver samples because most organ functions cease to work after death; in fact, with increasing post-mortem intervals (PMI), the brain and liver tissues deteriorate rapidly. Standard procedures of mitochondria isolation, protein determination expressed as BSA equivalent, and spectrophotometric assessment of pore opening at 540 nm were employed. Our results showed that (a) intact mitochondria may be isolated from rat brain and liver of these rats after storage in animal body (in situ) at −20 °C for 7 days (168 h, post-mortem), (b) some population of these mitochondria can still take up exogenous Ca2+ and (c) they can still resist osmotically induced large amplitude swelling in a suitable buffer. The need for mitochondrial purity, structural integrity and abundance for functional studies are common hindrances that can encumber mitochondrial research. Therefore, this study is significant to have shown that PMI up to 7 days did not extensively, diminish MMPT pore status in normal and diabetic, ovariectomised rats. This can be relevant for forensic data mining.

Quantitation of Fentanyl and Metabolites from Liver Tissue Using a Validated QuEChERS Extraction and LC-MS-MS Analysis.

According to the National Institute on Drug Abuse (NIDA), more than one hundred people die every day from opioid overdose. Overdose fatalities have risen as the availability of potent synthetic opioids, such as fentanyl, has increased. A forensic postmortem toxicological specimen is often in various stages of decomposition, experiencing autolysis and putrefaction, which complicates the extraction, creating a difficult challenge for toxicologists. Isolating the target drug, while creating an efficient and simplified analytical scheme, is a goal for most toxicology laboratories. The validation of a quick, easy, cheap, effective, rugged and safe extraction protocol is presented in this study as an alternative analytical method for efficient extraction and detection of fentanyl and its major metabolites: norfentanyl and despropionyl fentanyl (4-ANPP). The liquid Chromatography with tandem mass spectrometry analysis was validated following the American Academy of Forensic Sciences Standards Board (ASB) standard 036 proposed requirements. Evaluated parameters include selectivity, matrix effects (MEs), linearity, processed sample stability, bias, precision and proof of applicability using liver samples from authentic postmortem cases. MEs (represented as percent ionization suppression or enhancement) at low and high concentrations were -10.0% and 1.4% for fentanyl, -2.1% and -0.3% for 4-ANPP and 3.1% and 2.8% for norfentanyl, respectively. Bias for the three analytes ranged from -8.5% to -19.9% for the low concentrations, -3.6% to -14.7% for the medium concentrations and 1.5% to -16.1% for the high concentrations with all being within the ±20% guideline. Precision for the three analytes ranged from 2.2% to 15.1%. The linear range for the fentanyl and norfentanyl was 0.5-100 and 4-ANPP had a linear range of 0.4-80μg/kg. The authentic postmortem liver samples ranged in fentanyl concentrations from 56.6 to 462.3μg/kg with a mean of 149.2μg/kg (n=10). The range of norfentanyl concentrations were 1.9 to 50.0μg/kg with a mean of 14.1μg/kg (n=10). The range of 4-ANPP concentrations were 3.2 to 23.7μg/kg with a mean of 7.5μg/kg (n=7).

Heroin Fatality in a Feline: A Case Report with Postmortem Liver Concentrations

A case of feline intoxication and fatality with the illicit drug heroin is described. A 5-year-old castrated male domestic shorthair cat was recently diagnosed with an active pneumonitis and left at home for a couple of days under the care of another resident. Upon return, the owner found his cat dead with strong suspicion of foul play. The cat was necropsied by a local veterinary clinic to retrieve the liver for diagnostic toxicology. The postmortem liver sample screened positive for 6-acetylmorphine and 6-acetylcodeine by gas chromatography mass spectrometry. Deconvolution techniques were applied to chromatograms, which revealed the additional presence of morphine and mirtazapine. Subsequent quantitation of mirtazapine, heroin, morphine, 6-acetylmorphine and 6-acetylcodeine was performed by gas chromatography--tandem quadrupole mass spectrometry. Although companion animal fatalities arising from toxicities are a likely consequence of drug abuse in a home, this is the first reported case of a malicious feline fatality resulting from heroin with quantitation of heroin metabolites.

Ontogeny Related Changes in the Pediatric Liver Metabolome.

Background: A major challenge in implementing personalized medicine in pediatrics is identifying appropriate drug dosages for children. The majority of drug dosing studies have been based on adult populations, often with modification of the dosing for children based on size and weight. However, the growth and development experienced by children between birth and adulthood represents a dynamically changing biological system, with implications for effective drug dosing, efficacy as well as potential drug toxicity. The purpose of this study was to apply a metabolomics approach to gain preliminary insights into the ontogeny of liver function from newborn to adolescent.Methods: Metabolites were measured in 98 post-mortem pediatric liver samples in two experiments 3 batches of samples, allowing for both technical and biological validation. After extensive quality control, imputation and normalization, non-parametric tests were used to determine which metabolite levels differ between the four age groups (AG) ranging in age from newborn to adolescent (AG1—children <1 year; AG2—children with age between 1 and 6 years; AG3—children with age between 6 and 12 years; AG4—children with age between 12 and 18 years). To identify which metabolites had different concentration levels among the age groups, Kruskal-Wallis and Spearman correlation tests were conducted. Pathway analysis utilized the Gamma Method. Correction for multiple testing was completed using Bonferroni correction.Results: We found 41 metabolites (out of 884) that were biologically validated, and of those 25 were technically replicated, of which 24 were known metabolites. For the majority of these 24 metabolites, concentration levels were significantly lower in newborns than in the other age groups, many of which were long chain fatty acids or involved in pyrimidine or purine metabolism. Additionally, we found two KEGG pathways enriched for association with age: betaine metabolism and alpha linolenic acid and linoleic acid metabolism.Conclusions: Understanding the role that ontogeny of childhood liver plays may aid in determining better drug dosing algorithms for children.

Iron deposition in autopsied liver specimens from older patients receiving intravenous iron infusion.

Vitamins and minerals are routinely administered by total parenteral nutrition (TPN). However, in Japan, adjustments in iron dosage are difficult because blended mineral preparations are often used. It is therefore unclear whether the iron content is appropriate in cases of long-term TPN. The aim of the study was to assess the influence of iron administration by long-term TPN on iron deposition in post-mortem liver samples isolated from older deceased patients. Liver tissues were collected from post-mortem autopsies of 187 patients over a period of 15 years. Samples were stained with Prussian blue and histologically evaluated from Grade 0-V by at least three different observers. Specimens with positive and negative iron staining were compared, and positive samples were grouped according to the level and distribution of the staining. Post-mortem blood obtained from the subclavian vein during autopsy was also analysed. Samples were collected for the measurement of unsaturated serum iron, serum iron, albumin, prealbumin, hepcidin, and IL-6 concentrations. Iron accumulation in the liver was significantly higher in male patients (p = 0.005) with a history of surgery (p = 0.044) or central vein administration of iron (p<0.001). Additionally, the duration of TPN in the iron-positive group was significantly longer than in the iron-negative group (p = 0.038). Serum analysis revealed that unsaturated serum iron was significantly higher in the iron-negative group and that ferritin and serum iron were significantly higher in the iron-positive group. No other statistically significant differences were observed between the two groups. Chronic intravenous administration of iron was associated with iron deposition in the liver, even when given the minimum recommended dosage. In long-term TPN patients, the iron dose should therefore be carefully considered.

Metabolomics Reveals Altered Hepatic Bile Acids, Gut Microbiome Metabolites, and Cell Membrane Lipids Associated with Marginal Vitamin A Deficiency in a Mongolian Gerbil Model.

This study is designed to provide a broad evaluation of the impacts of vitamin A (VA) deficiency on hepatic metabolism in a gerbil model. After 28 days of VA depletion, male Mongolian gerbils (Meriones unguiculatus) are randomly assigned to experimental diets for 28 days. Groups are fed a white-maize-based diet with ≈50µL cottonseed oil vehicle either alone (VA-, n=10) or containing 40µg retinyl acetate (VA+, n=10) for 28 days. Liver retinol is measured by high-performance liquid chromatography. Primary metabolomics, aminomics, lipidomics, bile acids, oxylipins, ceramides, and endocannabinoids are analyzed in post-mortem liver samples by liquid chromatography-mass spectrometry. Liver retinol is lower (p<0.001) in the VA- versus VA+ group, with concentrations indicating marginal VA deficiency. A total of 300 metabolites are identified. Marginal VA deficiency is associated with lower bile acids, trimethylamine N-oxide, and a variety of acylcarnitines, phospholipids and sphingomyelins (p<0.05). Components of DNA, including deoxyguanosine, cytidine, and N-carbomoyl-beta-alanine (p<0.05), are differentially altered. Hepatic metabolomics in a marginally VA-deficient gerbil model revealed alterations in markers of the gut microbiome, fatty acid and nucleotide metabolism, and cellular structure and signaling.

EVALUATION OF THE MORPHOFUNCTIONAL STATE OF THE LIVER BY MORPHOMETRIC METHODS

Objectives. Morphometry of the main vascular and parenchymal structures of the liver which reflect its morphofunctional state.Material and methods. We examined the postmortem liver samples from 15 cases of rapid death of youth and adult men (26.6 % and 40 %, respectively) and women (13.4 % and 20 %, respectively). For histological studies we used archival paraffin-embedded tissue blocks of the liver. A series of 5 μm sections were made. Tissue sections were stained with hematoxylin-eosin. Random fields of view of histological slides were photographed with the OLYMPUS XC30 digital camera mounted on the OLYMPUS CX41 microscope (Japan) with SWH ocular magnification ×10 and UPLanFL aim magnifications ×10, ×20, ×40 (at least 10 fields of view of each slide). Morphometric data analysis was carried using Image Scope Color viewing program and Olympus cellSens imaging software (Japan). Statistical analysis was carried out using the software STATISTICA 10.Results. The liver microvasculature vessels have different diameters: the largest one corresponds to the interlobular veins ((87.80 ± 1.84) μm), the smallest corresponds to the interlobular arteries ((25.62 ± 2.41) μm). The diameter of the central vein is (54.03 ± 0.86) μm. The diameter of sinusoids is (28.36 ± 0.93) μm, interlobular bile ducts – (13.86 ± 0.80) μm. The areas of hepatocytes and nuclei are of (486.14 ± 11.15) μm2 and (58.89 ± 1.86) μm2, respectively; the area of the cytoplasm is (427.25 ± 9.19) μm2. The nuclear cytoplasmic ratio is 0.137 ± 0.06.Conclusion. The obtained morphometric data can be used for the comparison when studying the pathological features of the liver in other pathological conditions such as alcohol intoxication. Further development of this research area is required to select morphometric characteristics and map the relative morphometric norm of a “healthy” liver.

The thanatotranscriptome: Gene expression of male reproductive organs after death

The prostate gland is one of the last internal organs to deteriorate during human decomposition; however, this phenomenon is still mysterious. Gene expression in antemortem cases has been widely studied and a majority of the analyses concentrate on discovering basic physiological processes. The question of “What happens to gene expression after a human dies?” is a novel and emerging topic. Thanatotranscriptome (thanatos-, Greek for death) involves research on mRNA transcript abundances and gene expression in human tissues after death. Our previous studies have shown that RNA is a suitable and stable molecule in postmortem liver samples up to two days. Consequently, we hypothesized that there are also measurable and significant differences in mRNA transcript abundances in prostate tissues from human remains. In the current study, the goal was to identify apoptotic molecular markers (i.e., pro- and/or anti-apoptosis genes) that provide accurate gene expression profiles regarding the time of death.Tissue samples were removed by a medical examiner from the prostate of five cadavers during autopsy. After RNA extraction, cDNA was synthesized and the concentration was determined. The cDNA was reacted in apoptosis-related gene expression profiling by human PCR Array. The PCR Array results showed that at 38 h after death, a majority of the genes for apoptosis induction and positive regulation (i.e., caspases) were over-expressed more than at five days. The expression of anti-apoptotic genes such as BAG1, BCL2, and negative regulator of apoptosis, XIAP, was significantly elevated in a time-dependent manner. However, pro-apoptotic gene expression such as TP53 and TNFSF10 was not significantly upregulated.Therefore, postmortem prostate cells counteract programmed cell death with its anti-apoptotic machinery; yet as time progresses, pro-apoptotic mechanisms dominate. In conclusion, our study implies that over-expression of genes in male reproductive organs still occurs during decomposition, which may play substantial roles in forensic research and clinical application. These findings demonstrate that there is still active postmortem gene expression; however, our future research question will be, “When does gene expression terminate after death?”

Amphetamine in postmortem liver sample?

The aim of this paper is to present the formation of false positive amphetamine in postmortem liver samples and to determine conditions that are responsible for its formation.

Amphetamine in postmortem liver sample?

Amphetamine in postmortem liver sample?

Characterization of the Postmortem Interval by Infrared Microscopy

ABSTRACTThe objective of this study was to develop a novel and effective method for the evaluation of the postmortem interval using infrared microspectroscopy. Postmortem rat liver samples were investigated at 10, 20, and 30°C. Time-dependent changes in the images were observed from variations in the spatial distribution in the liver tissue that were correlated with the postmortem interval. This relationship, which has not been reported previously, offers a novel approach to supplement conventional forensic methods.

Ontogeny of human hepatic and intestinal transporter gene expression during childhood: age matters.

Many drugs prescribed to children are drug transporter substrates. Drug transporters are membrane-bound proteins that mediate the cellular uptake or efflux of drugs and are important to drug absorption and elimination. Very limited data are available on the effect of age on transporter expression. Our study assessed age-related gene expression of hepatic and intestinal drug transporters. Multidrug resistance protein 2 (MRP2), organic anion transporting polypeptide 1B1 (OATP1B1), and OATP1B3 expression was determined in postmortem liver samples (fetal n = 6, neonatal n = 19, infant n = 7, child n = 2, adult n = 11) and multidrug resistance 1 (MDR1) expression in 61 pediatric liver samples. Intestinal expression of MDR1, MRP2, and OATP2B1 was determined in surgical small bowel samples (neonates n = 15, infants n = 3, adults n = 14). Using real-time reverse-transcription polymerase chain reaction, we measured fetal and pediatric gene expression relative to 18S rRNA (liver) and villin (intestines), and we compared it with adults using the 2(-∆∆Ct) method. Hepatic expression of MRP2, OATP1B1, and OATP1B3 in all pediatric age groups was significantly lower than in adults. Hepatic MDR1 mRNA expression in fetuses, neonates, and infants was significantly lower than in adults. Neonatal intestinal expressions of MDR1 and MRP2 were comparable to those in adults. Intestinal OATP2B1 expression in neonates was significantly higher than in adults. We provide new data that show organ- and transporter-dependent differences in hepatic and intestinal drug transporter expression in an age-dependent fashion. This suggests that substrate drug absorption mediated by these transporters may be subject to age-related variation in a transporter dependent pattern.

Effects of Prolonged Pneumoperitoneum on Hepatic Perfusion During Laparoscopy

To assess the influence of prolonged pneumoperitoneum (PP) on liver function and perfusion in a clinically relevant porcine model of laparoscopic abdominal insufflation. PP during laparoscopic surgery produces increased intra-abdominal pressure, which potentially influences hepatic function and microcirculatory perfusion. Six pigs (49.6 ± 5.8 kg) underwent laparoscopic intra-abdominal insufflation with 14 mm Hg CO2 gas for 6 hours, followed by a recovery period of 6 hours. Two animals were subjected to 25 mm Hg CO2 gas. Hemodynamic parameters were monitored, and damage parameters in the blood were measured to assess liver injury. Liver total blood flow and function were determined by the indocyanine green (ICG) clearance test. Intraoperative hepatic hemodynamics were measured by simultaneous reflectance spectrophotometry (venous oxygen saturation StO2 and relative tissue hemoglobin concentration rHb) and laser Doppler flowmetry (blood flow and flow velocity). Postmortem liver samples were collected for histological evaluation. A decrease in microvascular perfusion was observed during PP. After 6 hours of PP, ICG clearance increased (P < 0.001), indicating a compensatory improvement of overall liver blood flow resulting in concomitantly improved microcirculatory perfusion (P = 0.024). Minimal parenchymal damage (aspartate aminotransferase) of the liver was seen after 6 hours of PP (P = 0.006), which seemed related to PP pressure. Minor histological damage was observed. The liver sustains no additional damage due to prolonged PP during laparoscopic surgery. Our findings suggest that prolonged PP does not hamper liver function or cause liver damage after extended laparoscopic procedures.