Liver Autopsy Samples Research Articles

Upregulation of major histocompatibility complex class II antigens in hepatocytes in Doberman hepatitis

Major histocompatibility complex (MHC) class II antigen expression in hepatocytes and its correlation with mononuclear cell infiltration into the liver were studied using immunohistochemical techniques in 38 Dobermans with Doberman hepatitis (DH). Liver biopsy samples were obtained from 18 dogs at the subclinical stage. Autopsy samples were taken from 6 DH dogs euthanized for a reason other than DH, from 14 dogs euthanized because of advanced liver failure and from 6 control Dobermans. Upon examination of the control liver samples, no expression of MHC class II antigens was detected in hepatocytes. By contrast, in 15 of the 18 DH biopsies (83%) and in all 20 DH autopsy liver samples, hepatocytes expressed MHC class II molecules. MHC class II expression was either cytoplasmic or membranous and occurred in conjunction with lymphocyte infiltration. A correlation between the inflammatory reaction and the expression of MHC class II in hepatocytes suggests that the aberrant expression of MHC class II in hepatocytes is induced by cytokines. Hepatocytes presenting a putative MHC class II molecule-associated autoantigen could thus become the target of an immune attack mediated by CD4+ T cells. In addition, corticosteroid treatment was observed to significantly decrease MHC class II expression in DH hepatocytes. Inappropriate MHC class II expression in hepatocytes and mononuclear cell infiltration are suggesting an autoimmune nature for chronic hepatitis in Dobermans.

Antiviral effect of adefovir in combination with a DNA vaccine in the duck hepatitis B virus infection model

Background/Aims : Combination of antiviral drugs with immunotherapeutic approaches may be a promising approach for the treatment of chronic hepatitis B. We used the duck HBV (DHBV) infection model to evaluate the efficacy of the combination of adefovir with DNA-immunization by comparison with the respective monotherapies. Methods : Pekin ducks chronically infected with DHBV received adefovir treatment alone or in association with intramuscular immunization with a plasmid (pCI-preS/S) expressing the DHBV large envelope protein. Ducks immunized with pCI-preS/S plasmid alone and two control groups receiving empty plasmid injections or no treatment were followed in parallel. Results : All animals treated with adefovir showed a marked drop in viremia titers during drug administration, followed by a rebound of viral replication after drug withdrawal. Eight weeks after the third DNA boost, the median of viremia within the duck group receiving the combination therapy tended to be lower compared to that of the other groups. In addition, our results suggest a trend to an additive effect of adefovir and DNA vaccine since a 51% decrease in DHBV DNA was observed in autopsy liver samples from combination therapy group, whereas pCI-preS/S or adefovir monotherapies decreased intrahepatic viral DNA by 38 and 14%, respectively. This effect was sustained since it was observed 12 weeks after the end of therapy. Conclusions : Our results suggest that combination of adefovir with DNA-vaccine may be able to induce a sustained antiviral effect in vivo.

Cadmium and lead levels in human liver and kidney samples obtained from Bursa Province

Autopsy samples of liver and kidney from 43 Turk cadavers obtained from the Department of Forensic Medicine of Bursa City were analysed for cadmium and lead. All subjects were born between 1918 and 1982. The means of cadmium residue levels were found to be 0.63235 - 0.06345 ppm in the liver and 0.8507 - 0.077 ppm in the kidney. The means of lead residue levels were measured as 0.44675 - 0.0591 ppm in the liver and 0.42905 - 0.0528 ppm in the kidney. In addition, the cadavers were grouped according to sex, age and place of dwelling, city or village. Although samples contained both of the metals in their normal levels, it was concluded that these results do not indicate whether both of the metals will be a serious threat to public health in the future.

Subtoxic Hepatic Vitamin A Concentrations in Captive Rhesus Monkeys (Macaca mulatta)

Although the rhesus monkey (Macaca mulatta) is a widely used experimental animal, its exact vitamin A requirement is unknown. An amount of 430-3600 IU/d [129-1080 retinol equivalents (RE)] is recommended, largely on the basis of depletion studies. Normal hepatic vitamin A appears to be 1 micromol/g liver. Our goal was to determine hepatic vitamin A concentrations of captive monkeys. Liver autopsy samples from rhesus and marmoset (Callithrix jacchus) monkeys were obtained from the Wisconsin Regional Primate Research Center. The rhesus monkeys consumed a diet with 40 IU (12 RE) retinyl acetate/g. Male and female monkeys consumed an estimated 250 and 175 g diet/d, respectively. Marmosets were fed a powder-based diet consisting of 20 IU (6 RE) retinyl acetate/g. The marmosets consumed an estimated 25 g of the diet/d. Liver samples were extracted and analyzed by HPLC. The vitamin A concentration of the rhesus monkey livers was very high at 17.0 +/- 6.3 micromol/g. The hepatic vitamin A of the marmosets was 1.25 +/- 0.58 micromol/g liver. Histologic examination of the livers revealed Ito cell hypertrophy and hyperplasia in the rhesus monkeys compared with the marmosets. Considering that the natural diet of the rhesus monkey (fruits, seeds, roots and insects) is not high in preformed vitamin A, the vitamin A content of the diet appears excessive, supplying four times the NRC recommendation and resulting in high liver stores.

The mutation in the mitochondrial aldehyde dehydrogenase (ALDH2) gene responsible for alcohol-induced flushing increases turnover of the enzyme tetramers in a dominant fashion.

Deficiency in mitochondrial aldehyde dehydrogenase (ALDH2), a tetrameric enzyme, results from inheriting one or two ALDH2*2 alleles. This allele encodes a protein subunit with a lysine for glutamate substitution at position 487 and is dominant over the wild-type allele, ALDH2*1. The ALDH2*2-encoded subunit (ALDH2K) reduces the activity of ALDH2 enzyme in cell lines expressing the wild-type subunit (ALDH2E). In addition to this effect on the enzyme activity, we now report that ALDH2*2 heterozygotes had lower levels of ALDH2 immunoreactive protein in autopsy liver samples. The half-lives of ALDH2 protein in HeLa cell lines expressing ALDH2*1, ALDH2*2, or both were determined by the rate of loss of immunoreactive protein after inhibition of protein synthesis with puromycin and by pulse-chase experiments. By either measure, ALDH2E enzyme was very stable, with a half-life of at least 22 h. ALDH2K enzyme had an enzyme half-life of only 14 h. In cells expressing both subunits, most of the subunits assemble as heterotetramers, and these enzymes had a half-life of 13 h. Thus, the effect of ALDH2K on enzyme turnover is dominant. These studies indicate that the ALDH2*2 allele exerts its dominant effect both by interfering with the catalytic activity of the enzyme and by increasing its turnover. This represents the first example of a dominantly acting allele with this effect on a mitochondrial enzyme's turnover.

Liver and chorion cytochemistry.

Microscopic visualization of peroxisomes in chorionic villus cytotrophoblast and in biopsy and autopsy samples of liver and kidney, the presence of enlarged liver macrophages containing lipid droplets insoluble in acetone and n-hexane as well as polarizing inclusions formed by stacks of trilamellar sheets are of diagnostic value in peroxisomal disorders. Methods are presented for evaluating these structures by light microscopy; trilamellar inclusions are only detected by electron microscopy. Macrophage features are preserved in archival paraffin blocks. In adrenal cortex, insoluble lipid, polarizing inclusions and trilamellar structures should be looked for. The stains are easily reproducible, and all reagents are commercially available.

Identification of drugs in autopsy liver samples by instrumental qualitative thin-layer chromatography

An instrumental thin-layer chromatographic (TLC) procedure is described for the identification of drugs with use of corrected R F values ( hR F c) and in situ ultraviolet spectra. One hundred and eleven successive autopsy liver samples received from medical examiners were investigated by this technique and the results were compared to those obtained with a reference method. From the nineteen findings by the reference method, sixteen (84%) were correctly identified by the instrumental TLC method, using an hR F c pre-search with a window size of +/-7 units followed by a correlation search. In addition one drug was identified correctly by correlation search only. There was no serious interference from endogenous substances, and a correlation value of about 0.9 is suggested as a limit to cut the hit list of candidates.

Restriction fragment length polymorphism of the human CYP2E1 (cytochrome P450IIE1) gene and susceptibility to lung cancer: possible relevance to low smoking exposure.

Polymorphic metabolism of certain chemical carcinogens may result in differences in susceptibility to cancers. Human CYP2E1 (cytochrome P450IIE1) is an enzyme involved in the metabolic activation of precarcinogens such as nitrosamines. We detected a restriction fragment length polymorphism (RFLP) of the human CYP2E1 gene for the restriction endonuclease Dra I. The distribution of this polymorphism was examined among lung cancer patients (n = 91), patients with cancer of the digestive tract (n = 45) and controls (n = 76). A significant difference in the distribution was observed between lung cancer patients and controls (chi 2 = 11.4 with 2 df; p < 0.005). On the other hand, there was no significant difference between patients between cancer of the digestive tract and controls (chi 2 = 4.87 with 2 df; NS). This finding suggests that the Dra I polymorphism of the CYP2E1 gene is associated with susceptibility to lung cancer. In addition, an association was found between the amount of lifelong smoking exposure and the distribution of the genotypes of the RFLP among lung cancer patients. The distribution pattern seemed deviated from that of controls especially in the population of low smoking exposure. Our Northern blot analysis data using RNA from human liver autopsy samples suggest that the Dra I polymorphism might be associated with the gene expression of CYP2E1 at mRNA level.

Cobalt-vitamin B-12 interrelationships in liver of fetuses and infants

The concentrations of cobalt and vitamin B-12 were measured in 90 autopsy samples of liver from fetuses and newborn infants from the city of Brasilia, Brazil. Gestational age varied from 19–42 weeks. Vitamin B-12 was assayed by L. Ieichmannii, and cobalt by electrothermal atomic absorption spectrophotometry. Concentrations on a wet weight basis of vitamin B-12 ranged from 83–758 ng/g of liver (293.15 + 14.91; mean + SEM), and of cobalt ranged from 6–45 ng/g liver (17.68 ± 0.85; mean ± SEM). The percentage of cobalt as vitamin B-12 ranged from 23–100 (72.4 ± 1.8; mean ± SEM). The percentage of cobalt as vitamin B-12 was not affected by fetal development measured as liver weight ( r = 0.08; P < 0.4). Liver weight was not significantly correlated with concentrations of either cobalt ( r = −0.16; P < 0.14) or vitamin B-12 ( r = −0.15; P < 0.14). However, the correlation between cobalt and vitamin B-12 concentrations was highly significant ( r = 0.83; P < 0.0001). Concentration of vitamin B-12 can be derived from cobalt concentration by the equation [vitamin B-12] = 14.62x[Co] + 34.48.

Monomorphism of Formaldehyde Dehydrogenase in Different Populations

Blood samples from Koreans, Chinese, Hungarians and Germans were analyzed by isoelectric focusing on polyacrylamide gels and stained for formaldehyde dehydrogenase (FDH) activity. Three activity bands (one major and two minor) were observed in all blood samples studied. No distinct intra- and interpopulation differences were observed in the intensity of the three bands. Human autopsy liver samples also showed a similar three-activity band profile. An additional cathodic band was detected in a single case of autopsy liver extract from a Chinese subject. An apparent identity of FDH with the class III alcohol dehydrogenase was confirmed.

Preliminary study of the distribution of the toxic elements As, Cd, and Hg in human hair and tissues by RNAA

In order to study the relationships between trace element concentrations of hair and internal body burdens, a radiochemical NAA technique has been used for determination of the elements As, Cd, and Hg in autopsy samples of liver, kidney-cortex, lung, and hair from 24 male persons who died by accident. High significant positive correlations were observed between the As concentration in hair and in kidney-cortex, and between Cd and Zn concentrations in kidney-cortex. The contents of Cd, both for lung and kidney-cortex, were related to the smoking habits of the subjects.

Deficit of uridine diphosphate galactose in galactosaemia

The levels of uridine diphosphate galactose (UDPGal) and uridine diphosphate glucose (UDPGlc) have been determined in liver autopsy samples, erythrocytes and cultured skin fibroblasts from galactosaemic patients and compared to non-galactosaemic controls. In patients with undetectable erythrocyte galactose-1-phosphate uridyltransferase (transferase) activity, the levels of UDPGal were substantially lower than in controls. In patients with detectable transferase activity, even though in less than 1% of normal values, both UDPGal and UDPGlc levels were in the normal range. Incubation of erythrocytes from both galactosaemic patients and normal individuals with 10 mmol/L uridine increased UDPGal and UDPGlc levels several-fold, both in the presence or absence of galactose in the incubation medium. We hypothesize that a deficit of UDPGal is responsible for the late onset clinical manifestations in galactosaemia which include ovarian failure, speech defect and neurological abnormalities. We suggest that uridine administration may be of therapeutic value in raising the intracellular concentrations of UDPGal. We conclude that the transferase reaction, however small in activity, is essential for optimal UDPGal formation.

Aflatoxins and Child Health in the Tropics

AbstractThe geographical distribution, seasonal incidence, biochemical and biological derangements observed in Kwashiorkor, a serious and prevalent disease in childhood of obscure aetiology, are remarkably similar to those recorded in epidemiological and animal studies on aflatoxins.Possible relationships between kwashiorkor and aflatoxins have been explored over the past 8 years in 8 countries. Aflatoxins have been detected more frequently and at higher concentrations in the sera of kwashiorkor than other children; aflatoxicol is frequently detected in sera of kwashiorkor but never in controls; autopsy liver samples from kwashiorkor contained aflatoxin B1 or aflatoxicol; and children with kwashiorkor, on an aflatoxin free diet, excrete large amounts of aflatoxin in their stools for up to 10 days. These findings have established definite relationships between kwashiorkor and aflatoxins.The apparent reduced susceptibility of kwashiorkor to P.falciparum malaria, led to the study of the influence of aflatoxi...

Glutamate-pyruvate transaminase subtypes in Singapore ethnic groups.

Autopsy liver samples from 244 Chinese, 119 Malays and 136 Indians were screened for glutamate-pyruvate transaminase (GPT) subtypes by starch-gel electrophoresis and isoelectric focusing at pH 5-7. Altogether, ten phenotypes controlled by four alleles (GPT1, GPT2A, GPT2B and GPT3) were identified. There was no significant difference in the frequency of GPT alleles between the ethnic groups. The distribution of GPT types was in agreement with the Hardy-Weinberg equilibrium in all the ethnic groups.

Cadmium, zinc, copper and metallothionein levels in human liver.

The concentrations of cadmium, zinc, copper and metallothionein in the autopsy samples of liver among the inhabitants of Lódź (Poland) were determined. The cadmium levels were low in the range of 1.5 to 5.8 micrograms/g. The concentration of metallothionein determined by the Hg-method was high (0.160-1.665 mumol Hg/g); it was mainly a Zn-thionein. The percentage of hepatic zinc bound in the MT-fraction increased with the overall content of zinc in the liver. The elevation of zinc in the liver occurs in the proportion required for the saturation of metal-binding ligands of metallothionein. The role of cadmium remains less clear. Our results suggest that the metallothionein level in the liver increase significantly in response to elevated cadmium concentrations. This response, however, is in high excess to the demand which is justified stoichiometrically.

Molecular and pharmacogenetic basis of alcohol intolerance

Alcohol affects major psychomotor functions through a series of complex physiochemical metabolic processes. Ethnic and cultural factors are among the strongest determinants of drinking patterns in a society. People differ in physiological and morphological features which could influence their drinking behavior and metabolic responses to alcohol. The variations in individual responses to alcohol are genetically controlled and distributed among different levels. Individuals differ in their genotypes of specific enzymes involved in alcohol metabolism, and genetic differences may underlie different rates of ethanol metabolism, and resulting physiological responses. Ethanol is oxidized to acetaldehyde via hydrogen transfer from the substrate to the cofactor NAD, resulting in the conversion to NADH. Aldehyde dehydrogenase (ALDH) catalyzes the oxidation of acetaldehyde to acetic acid. The metabolism of acetaldehyde has received considerable attention in the past ten years owing to its acute and chronic toxic effects. About 50% of Japanese and Chinese autopsy livers lack in ALDH I isozyme. While Oriental populations showed varying degrees of isozyme deficiency (8–53%), none of the Caucasian or Negroid populations have this isozyme abnormality. Among native Indians, while about 40% of the South American Indian tribes (Mapuche, Atacamenos, Shuara) showed ALDH deficiency, the isozyme deficiency was detected in only 4–5% of Sioux, Navajo and Mestizo tribes. The isozyme deficiency is the result of a structural mutation leading to the synthesis of enzymatically less-functional or non-functional proteins. ALDH I-deficient liver extracts contain CRM with near loss of enzyme activity and diminished antigenic properties. The immunological CRM isolated from the ALDH I deficient Oriental liver has been found to contain an amino acid substitution; glumatic acid, at the 14th position from the carboxy terminus, is substituted in the deficient isozyme with lysine. Hybridization of human liver ALDH mRNA to the heterologic horse liver RNA as well as length comparison suggests a very close relationship between horse and man at RNA level as also reported at the protein level. Northern blot analysis of human adult and fetal liver revealed 4–5-fold stronger hybridization signals in the adult liver. Generally, a lower transcription level of ALDH I gene was observed in fetal tissues than in the corresponding adult tissues. The chromosomal localization of ALDH I gene has been determined by nick-translating a cDNA fragment of ALDH I corresponding to the C-terminal end of the protein and subjecting it to Southern blot hybridization with a panel of human and rodent hybrid cells. Co-segregation in hybrid clones was observed between all marker bands and human chromosome 12. Differences in euphoric and dysphoric response to alcohol are observed frequently in various ethnic and racial groups. The symptoms include facial flushing, increase in heart rate, burning in the stomach, palpitation, tachycardia, muscle weakness, etc. A greater percentage of Orientals have been found to respond adversely to a mild dose of ethanol than the Caucasian subjects. The flushing response to alcohol shows familial resemblances. A positive correlation between alcohol sensitivity and elevated blood acetaldehyde level in conjunction with ALDH I deficiency was noted in Japanese subjects given an acute dose of alcohol. The initial vasomotor flushing after alcohol ingestion in Orientals might be due to their inability to metabolize acetaldehyde quickly and effectively in the absence of the low K m ALDH isozyme I. Thus, impaired oxidation of acetaldehyde and not its higher-than-normal production through an atypical alcohol dehydrogenase (ADH) may be primarily responsible for alcohol sensitivity. Subjects who are deficient in ALDH I isozyme will experience unpleasant reactions after alcohol drinking and, hence, may be consuming less alcohol in daily life. Indeed, a highly significant correlation has been observed among Japanese in the regions of Sendai and Gifu regarding their annual per capita alcohol consumption and the incidence of ALDH deficiency in random autopsy liver samples. Similar studies correlating alcohol intolerance and alcohol consumption in a large number of Japanese men were reported recently. Flushers drank a small amount of alcohol compared to nonflushers who frequently drank a fairly large amount of alcohol and suffered from alcohol-related problems. In a large study on Korean and Taiwan Chinese, subjects showing fast flushing consumed substantially less amount of alcohol than those who exhibited no flushing or slow flushing. Individuals sensitive to alcohol by virtue of their genetically controlled deficiency of a key enzyme of alcohol metabolism may be discouraged from abuse of alcohol due to initial aversive reaction. Indeed, a significantly lower incidence of ALDH I isozyme deficiency was observed in a group of Japanese alcoholics than in a group of psychiatric patients, drug dependents and healthy controls. Whether ALDH isozyme deficiency also plays a protective role among native Americans has yet to be understood.

Alcohol and aldehyde dehydrogenase isoenzymes in North American Indians.

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) isoenzyme phenotypes were determined in autopsy liver samples from 50 North American Indians from New Mexico. Forty-six of the 50 livers had sufficient ADH activity to allow phenotyping at the ADH2 and ADH3 loci. All 46 livers possessed the "typical" ADH2 1-1 phenotype. The frequency of the ADH3(2) allele was 0.59 and is the highest thus far reported in any racial population. All 50 livers possessed the ALDH I isoenzyme which exhibits the greatest anodic mobility on starch gel electrophoresis at pH 7.6. The results show that ADH and ALDH phenotypes among American Indians living in New Mexico are very similar to those of Caucasian populations and quite different from those of Orientals.

Cytomegalovirus hepatitis in normal and immune compromised hosts

Liver biopsies of six previously normal hosts (Group I, NH), with recent or acute CMV infection, and autopsy liver samples of four immunocompromised hosts (Group II, ICH) with overwhelming CMV infection have been studied in an occasional survey. In both groups, portal tract involvement, bile duct inflammation, liver cell degeneration and parenchymal granulomas were present. In Group I, a randomly distributed hepatitis with predominant involvement of the periportal areas was present, including sinusoidal arrays of lymphocytes and lymphohistiocytic aggregates. In contrast, in Group II liver cell damage was more extensive and the inflammatory infiltration only scarce. Intracellular viral inclusion bodies were found only in Group II, both in liver cells and in bile duct epithelium. Morphologically, the presence of viral inclusion bodies correlated well with the immunohistologic demonstration of CMV specific "late" (CMV-LA) or structural antigens. In addition, CMV-specific "early" (CMV-EA) or non-structural antigens were present in liver cell nuclei of 2/6 NH and 2/4 ICH. The possible relations between the inflammation and the lack of structural antigenic viral expression are discussed. It is concluded that ICH with CMV infection have a prominent cytopathogenic effect and widespread lytic viral infection in the liver in the absence of adequate immunologic reactivity, whereas the opposite is found in NH.

In vitro synthesis of M and Z forms of human α 1-antitrypsin

mRNA was prepared from autopsy liver samples from a homozygote for α 1-antitrypsin deficiency ( PiZZ) and from a normal ( PiMM) subject. Both preparation gave equivalent synthesis of α 1-antitrypsin in a wheat germ cell-free system. This suggests that the deficiency of plasma α 1-antitrypsin associated with the Z variant is due to a failure of processing and secretion of the protein rather than of its synthesis. It is likely that it is the resultant intracellular accumulation of the Z protein rather than a deficiency of protease inhibitor that is the primary cause of the liver pathology associated with this variant.

Simultaneous determination of 20 elements in some human kidney and liver autopsy samples by inductively-coupled plasma atomic emission spectrometry

The argon supported inductively coupled plasma—atomic emission spectrometer (ICP—AES) is found to be an attractive analytical tool for the simultaneous multi-element determination of major, minor and trace elements in human liver and kidney specimens. The sample is digested with a mixture of HNO 3HClO 4. The damp residue is taken up in HCl, aspirated into the plasma and the resulting emission signals are detected by a polychromator where the analytical lines of the 20 elements determined are included as fixed channels. The method is rapid, precise, sensitive, less subject to interferences and cost-effective. A total of 20 elements in about 40 autopsy samples of human kidney (cortex and medulla) and liver taken from Canadian adults living in the Great Lakes Region of Ontario were determined using the wet digestion-ICP—AES technique.