Correlation between changes in membrane lipid composition induced by dietary lipid and membrane-bound enzyme activity in chick liver

The activity of acyl-CoA: cholesterol acyltransferase in the liver-microsomal fraction was considerably reduced in chicks fed on diet containing unsaturated fat, whereas the activity of HMG-CoA reductase and NADPH cytochrome c reductase was not affected. The fatty acid composition of the microsomes was modified appreciably by this dietary condition and there was no change in the phospholipid or cholesterol levels. The addition of cholesterol to the fat supplemented diet resulted in a considerable increase in the microsomal cholesterol content. A decrease in HMG-CoA reductase and an increase ACAT activity was observed compared with the corresponding values from both the groups fed on a standard diet and a fat supplemented diet with no cholesterol. These results suggest that acyl-CoA: cholesterol acyltransferase is modulated by alteration in the fatty acid composition of the microsomal membrane, while the cholesterol content of the microsomes shows a close relationship with the HMG-CoA reductase activity.     

Correlation between nortriptyline and debrisoquine hydroxylation in the human liver

The benzylic hydroxylation of nortriptyline (NT) and debrisoquine (D) by isolated human liver microsomes from eight subjects was studied. There was a strong correlation between the 10-hydroxylation of NT and the 4-hydroxylation of D (r = 0.96). The ability to hydroxylate D was also measured in vivo as the ratio between D and 4-OH-D in urine after oral administration of the drug to four subjects. This estimate of hydroxylation capacity agreed with the in vitro measurements. Liver microsomes from a subject defined as a poor in vivo oxidizer of D hydroxylated NT and D unusually slowly. Separation of microsomal proteins by SDS-gel electrophoresis indicated a relative lack of a cytochrome P-450 isozyme with a molecular weight of 54,500 in the liver from the poor oxidizer.     

Correlation between the number of centrioles and ploidy of mouse liver hepatocytes

Using the electron microscope it was shown that in interphase hepatocytes with ploidies equal to 2n, 2n.2, 4n, 4n.2 and 8n, the number of centrioles per cell exactly corresponded to the ploidy of the cell. Both in mononuclear and binuclear cells all the centrioles are accumulated in one complex in which each pair of centrioles forms a diplosome. In binuclear cells, the complex of diplosomes is situated at equal distances from each nucleus, thus making the cell centre. The involvement of the supernumerous centrioles in polyploid metaphase cells was detected for the regenerating liver of old mice. It was found that each mitotic pole had at least four centrioles. In the pole, a pair of centrioles forms diplosomes tightly connected to each other. It is suggested that the initially tetraploid cell might divide in this manner. In addition, a question is discussed on how the existence of centrioles can be associated with the mechanism of polyploidization.     

Comparison between histopathology and DNA histogram of testis

From January to July 1989, the DNA histogram of testicular open biopsies was done for 11 patients of primary infertility and 7 patients of a control group. There were 2 failures in these 36 specimens. The flow cytometric analysis revealed characteristic patterns in the relative numbers of haploid (1C), diploid (2C), and tetraploid (4C) cells. In the presence of normal spermatogenesis, the haploid compartment contained the majority of cells, followed by the diploid, and then the tetraploid (1C greater than 2C greater than 4C). The other diagnostic criteria of flow cytometry were as follows: hypospermatogenesis (2C greater than 1C greater than 4C), the maturation arrest (2C greater than 4C greater than 1C), and Sertoli-cell-only syndrome (2C, near 100%). According to the aforementioned diagnostic criteria, the results of DNA histograms were compared with the histopathology diagnosed by junior or senior pathologists. These patterns of DNA histograms correlated with the diagnoses by senior pathologists in 28 of 34 specimens (82.6%), while there were only 20 of 36 pathologic diagnoses (55.6%) which matched between junior and senior pathologists. It is shown that abundant experience is needed for testis pathologists to diagnose accurately. The DNA histograms correlate well with pathological findings, with the advantages of quantification and fewer specimens needed. In conclusion, testicular tubular cell DNA histograms appear to be a reliable modality in the evaluation of spermatogenesis. They provide the quantitative information of sperm maturation and help in making appropriate decisions in the management of male infertility.     

Genetically-engineered pig-to-baboon liver xenotransplantation: histopathology of xenografts and native organs

Orthotopic liver transplantation was carried out in baboons using wild-type (WT, n = 1) or genetically-engineered pigs (α1,3-galactosyltransferase gene-knockout, GTKO), n = 1; GTKO pigs transgenic for human CD46, n = 7) and a clinically-acceptable immunosuppressive regimen. Biopsies were obtained from the WT pig liver pre-Tx and at 30 min, 1, 2, 3, 4 and 5 h post-transplantation. Biopsies of genetically-engineered livers were obtained pre-Tx, 2 h after reperfusion and at necropsy (4–7 days after transplantation). Tissues were examined by light, confocal, and electron microscopy. All major native organs were also examined. The WT pig liver underwent hyperacute rejection. After genetically-engineered pig liver transplantation, hyperacute rejection did not occur. Survival was limited to 4–7 days due to repeated spontaneous bleeding in the liver and native organs (as a result of profound thrombocytopenia) which necessitated euthanasia. At 2 h, graft histology was largely normal. At necropsy, genetically-engineered pig livers showed hemorrhagic necrosis, platelet aggregation, platelet-fibrin thrombi, monocyte/macrophage margination mainly in liver sinusoids, and vascular endothelial cell hypertrophy, confirmed by confocal and electron microscopy. Immunohistochemistry showed minimal deposition of IgM, and almost absence of IgG, C3, C4d, C5b-9, and of a cellular infiltrate, suggesting that neither antibody- nor cell-mediated rejection played a major role.     

Correlation between acetylator phenotypes and genotypes of polymorphic arylamine N-acetyltransferase in human liver

Southern blot analysis was performed with genomic DNAs from 86 human subjects using the 32P-labeled cDNA for polymorphic arylamine N-acetyltransferase (EC 2.3.1.5) in human liver recently cloned in our laboratory. Three types of N-acetyltransferase gene were identified. Gene 1 contains a 5.5-kilobase (kb) KpnI fragment with a BamHI site; gene 2 contains a 5.5-kb KpnI fragment without a BamHI site; and gene 3 contains a 5.0-kb KpnI fragment with a BamHI site. The combination of these three genes generated five genotypes. Acetylator phenotypes were determined in 29 healthy volunteers by isoniazid loading tests, and they were classified as rapid (10 subjects), intermediate (16 subjects), or slow (3 subjects) acetylators. Rapid acetylators were homozygotes of gene 1. Intermediate acetylators were heterozygotes of either genes 1 and 2 or genes 1 and 3. There were two exceptional cases who were classified as intermediate acetylators but were homozygotes of gene 1. Slow acetylators were either heterozygote of genes 2 and 3 or homozygotes of gene 3. These results indicate that gene 1 corresponds to high N-acetyltransferase activity, while gene 2 and gene 3 give rise to low N-acetyltransferase activity.     

Correlation between human herpesvirus 6 and 7 infections after living related liver transplantation

Human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) are closely related to each other. Interaction between the two viruses at the time of primary HHV-7 infection is suggested by in vivo and in vitro studies. However, interaction between the two viruses in organ transplant recipients has not been analyzed. We analyzed serially collected plasma samples obtained from 40 living related liver transplant recipients by serological assay (indirect immunofluorescence assay, IFA) and polymerase chain reaction (PCR). Significant increase or seroconversion of HHV-6 IgG and HHV-7 IgG antibody titers were observed in 45% and 58% of recipients respectively. Positive rate of IgM HHV-6 antibody increased up to 35% at 4 weeks after transplantation. However, no remarkable peak in the positive rate of HHV-7 IgM antibody was demonstrated. HHV-6 and HHV-7 DNA were detected in plasma in 15 (38%) and 16 (40%) of the 40 recipients respectively. HHV-6 DNA was detected in 10 (26%) of the 38 recipients at 2 weeks after transplantation. The positive rate of the virus genome in plasma gradually decreased after that time. HHV-7 DNA was detected in 5 (14%) of the 37 recipients at 2 weeks after transplantation; no obvious peak in the positive rate of HHV-7 DNA was demonstrated. Antibody responses involving both HHV-6 and HHV-7, including either a significant increase in IgG antibody titers or positive identification of IgM antibody were observed in 17 (43%) of the 40 recipients. Thirteen out of the 17 recipients demonstrated concurrent antibody response against both viruses. HHV-7 antibody response preceded the HHV-6 antibody response in 2 of the remaining 4 recipients, whereas the opposite was true in the other 2 recipients. Both HHV-6 and HHV-7 DNA were detected in 7 (18%) of the 40 recipients. In 4 of those 7 recipients, DNA from both viruses was concurrently detected, 3 of whom had HHV-7 DNA repeatedly detected after first detection of the virus DNA. The detection of HHV-7 DNA preceded the detection of HHV-6 DNA in 2 recipients, whereas HHV-6 DNA appeared first in 1 recipient.     

菲对斑马鱼鳃和肝组织结构的影响

采用浓度为0、0.05和100.0 μg·L-1的菲水溶液对斑马鱼(Brachydanio rerio)进行36 d的暴露实验,研究了菲对斑马鱼鳃、肝结构的影响.H-E染色显示:在0.05和100.0 μg·L-1的菲溶液暴露下,受试鱼的鳃受到损伤,均发生鳃小片上皮细胞肥大和水肿;菲浓度为100.0 μg·L-1时,受试鱼还发生鳃丝上皮增厚、鳃小片上皮隆起现象.此外,菲暴露造成斑马鱼的肝组织损伤,0.05 μg·L-1的菲溶液暴露下,受试鱼的肝细胞发生肿大,胞质产生空泡;菲浓度为100.0 μg·L-1时,受试鱼的肝细胞变得不规则,细胞核萎缩变形和偏离细胞中心,部分肝细胞空泡化程度加重,发生核溶解或细胞溶解,造成局部肝组织坏死.表明水环境中菲浓度达到0.05 μg·L-1即已对斑马鱼的鳃、肝产生毒性作用;而菲浓度达到100.0 μg·L-1时,受试鱼的鳃、肝将受到较严重的损伤;伴随菲浓度的升高,鱼的鳃、肝损伤加重.     

Correlation between electric field pulse induced long-lived permeabilization and fusogenicity in cell membranes.

Electric field pulses have been reported to induce long-lived permeabilization and fusogenicity on cell membranes. The two membrane property alterations are under the control of the field strength, the pulse duration, and the number of pulses. Experiments on mammalian cells pulsed by square wave form pulses and then brought into contact randomly through centrifugation revealed an even stronger analogy between the two processes. Permeabilization was known to affect well-defined regions of the cell surface. Fusion can be obtained only when permeabilized surfaces on the two partners were brought into contact. Permeabilization was under the control of the pulse duration and of the number of pulses. A similar relationship was observed as far as fusion is concerned. But a critical level of local permeabilization must be present for fusion to take place when contacts are created. The same conclusions are obtained from previous experiments on ghosts subjected to exponentially decaying field pulses and then brought into contact by dielectrophoresis. These observations are in agreement with a model of membrane fusion in which the merging of local random defects occurs when the two membranes are brought into contact. The local defects are considered part of the structural membrane reorganization induced by the external field. Their density is dependent on the pulse duration and number of pulses. They support the long-lived permeabilization. Their number must be very large to support the occurrence of membrane fusion.     

慢性乙型肝炎患者肠道菌群与肝脏生化指标的相关性

乙型肝炎病毒感染引起的慢性乙型肝炎(Chronic hepatitis B,CHB)是一种全球性流行疾病,严重时可引起肝功能衰竭,甚至发展成肝硬化和肝癌.也已发现CHB的发生和发展与肠道菌群的组成和结构的变化密切相关.为进一步探究肠道菌群结构与肝脏生化指标之间的联系,文中随机纳入14名CHB患者和11名健康对照者(Co...