Immunohistochemical Determination of Hepatic Cytochrome P-4502E1 in Formalin-Fixed, Paraffin-Embedded Sections

Cytochrome P-4502E1 (2E1) is inducible by chronic ethanol consumption that results in enhanced activation of anesthetics and commonly used drugs (such as acetaminophen) to hepatotoxins. Therefore, assessment of hepatic 2E1 is needed in prescribing these drugs for the management of alcoholic patients. Currently, measurement of 2E1 requires either immunohistochemistry on frozen sections or Western blot (WB) analysis of homogenized tissue in excess of that needed for pathology. To obtain a more widely applicable method, we developed a procedure to detect 2E1 by immunohistochemistry in formalin-fixed, paraffin-embedded liver biopsies obtained routinely for diagnosis. Data were collected from rats fed ethanol-containing or control liquid diets for 3 weeks. lmmunostaining was performed using anti-human rabbit 2E1 antibody as the primary antibody, and the immunoreaction was detected by the avidin-biotin immunoperoxidase method after treating sections with target unmasking fluid, an antigen retrieval buffer that enhanced the staining of 2E1. In control rats, 2E1 staining was weak and perivenular. After ethanol feeding, it showed a lobular gradient, strongest perivenular and weakest periportal, similar to that seen in frozen sections. The staining intensity was scored as: 0 (no staining) to 3 (strong staining). The zonal staining was scored as follows: 1 = perivenular zonal staining, 2 = midzonal, and 3 = panlobular. With the product of the two scores, a significant difference was found between alcohol-fed and control rats (5.1 ± 0.3 vs. 0.8 ± 0.2, p < 0.001). 2E1 assessments by WB were also significantly different for these rat pairs (68.5 ± 2.1 vs. 7.9 ± 0.8 arbitrary units/mg protein, p < 0.001), with a parallel increase of immunostaining scores and WB measurement of 2E1 content. This immunohistochemical method was then validated in 14 paraffin-embedded percutaneous human liver biopsy samples. In livers of nonalcoholics, 2E1 staining was seen in the perivenular zone only, whereas in samples of alcoholics, the staining was perivenular to midzonal and sometimes periportal. A significant correlation between the zonal staining scores (r_s= 0.67, p < 0.005) or intensity ± zonal staining scores (r_s= 0.79, p < 0.001) and WB analysis was found. The immunohistochemical assessments of 2E1 expression in formalin-fixed, paraffin-embedded sections from livers of alcoholics was found to correlate with WB analysis, and lobular distribution was consistent with that seen in frozen sections. The proposed method should therefore be useful for the assessment of 2E1 content in paraffin-embedded liver samples, thereby aiding in the management of heavy drinkers.     

Alcohol-induced liver injury in mice lacking Cu, Zn-superoxide dismutase

Because alcoholic liver disease has been linked to oxidative stress, we investigated the effect of a compromised antioxidant defense system, Cu, Zn-superoxide dismutase (Sod1) deficiency, on alcohol-induced liver injury. C57BL/129SV wild-type (Sod1(+/+)) and Sod1 knockout (Sod1(-/-)) mice were fed dextrose or ethanol (10% of total calories) liquid diets for 3 weeks. Histologic evaluation of liver specimens of Sod1(-/-) mice fed ethanol showed the development of liver injury ranging from mild to extensive centrilobular necrosis and inflammation. Sod1(+/+) mice fed ethanol showed mild steatosis; both Sod1(+/+) and Sod1(-/-) mice fed the dextrose diet had normal histology. Alanine transaminase levels were significantly elevated only in Sod1(-/-) mice fed ethanol. Cytochrome P450 2E1 (CYP2e1) activity was elevated about 2-fold by ethanol in Sod1(+/+) and Sod1(-/-) mice. Ethanol consumption increased levels of protein carbonyls and lipid peroxidation aldehydic products in the liver of Sod1(-/-) mice. Hepatic adenosine triphosphate (ATP) content was reduced dramatically in Sod1(-/-) mice fed ethanol in association with a decrease in the mitochondrial reduced glutathione (GSH) level and activity of MnSOD. Immunohistochemical determination of 3-nitrotyrosine (3NT) residues in liver sections of the Sod1 knockout mice treated with ethanol showed a significant increase of 3NT staining in the centrilobular areas. In conclusion, a rather moderate ethanol consumption promoted oxidative stress in Sod1(-/-) mice, with increased formation of peroxynitrite, protein carbonyls, and lipid peroxidation and decreased mitochondrial GSH and MnSOD. We speculate that the increased oxidative stress causes mitochondrial damage and reduction of ATP content, leading to alcoholic liver injury. This model may be useful in further mechanistic studies on alcohol-induced liver injury.     

Two pathways of exocytosis of cytoplasmic granule contents and target cell killing by cytokine-induced CD3+ CD56+ killer cells

Cytokine-induced killer (CIK) cells are non-major histocompatibility complex-restricted cytotoxic cells generated by incubation of peripheral blood lymphocytes with anti-CD3 monoclonal antibody (MoAb), interleukin-2 (IL-2), IL-1, and interferon-gamma. Cells with the greatest effector function in CIK cultures coexpress CD3 and CD56 surface molecules. CIK cell cytotoxicity can be blocked by MoAbs directed against the cell surface protein leukocyte function associated antigen-1 but not by anti-CD3 MoAbs. CIK cells undergo release of cytoplasmic cytotoxic granule contents to the extracellular space upon stimulation with anti-CD3 MoAbs or susceptible target cells. Maximal granule release was observed from the CD3+ CD56+ subset of effector cells. The cytoplasmic granule contents are lytic to target cells. Treatment of the effector cells with a cell-permeable analog of cyclic adenosine monophosphate (cAMP) inhibited anti-CD3 MoAb and target cell- induced degranulation and cytotoxicity of CIK cells. The immunosuppressive drugs cyclosporin (CsA) and FK506 inhibited anti-CD3- mediated degranulation, but did not affect cytotoxicity of CIK cells against tumor target cells. In addition, degranulation induced by target cells was unaffected by CsA and FK506. Our results indicate that two mechanisms of cytoplasmic granule release are operative in the CD3+ CD56+ killer cells; however, cytotoxicity proceeds through a cAMP- sensitive, CsA- and FK506-insensitive pathway triggered by yet-to-be- identified target cell surface molecules.     

Interval between insulin injection and breakfast in diabetes

The relationship between the insulin-breakfast interval, postprandial increase in blood glucose, and glycaemic control was studied in 58 children with diabetes. Patients recorded insulin-breakfast intervals in a home diary over a seven day period, and during a 24 hour period at the weekend provided eight serial capillary dried blood spots for glucose analysis. The highest mean blood glucose value occurred two hours after breakfast and showed a significant correlation with fructosamine concentrations. Weekend insulin-breakfast intervals ranged from 2-30 minutes, with 70% reporting intervals of less than 15 minutes. There was a significant correlation between the weekend insulin-breakfast interval and the after breakfast increase in blood glucose with a mean increment of 0.4 mmol/l in the 30 minute group and 7.2 mmol/l in the 2 minute group. Over the whole study period, children with mean insulin-breakfast intervals of two to 12 minutes had a mean fructosamine concentration of 376 mumol/l compared with 341 mumol/l in those with intervals of 15-35 minutes. This study has shown that the interval between insulin injection and breakfast significantly influences the morning postprandial rise in blood glucose and consequently short term glycaemic control. It is therefore important that patients are encouraged to leave an interval of about 30 minutes between insulin injection and breakfast.     

Socio-demographic factors and self-reported funtional status: the significance of social support

Background  

The aim of the present work was to investigate the relative importance of socio-demographic and physical health status factors for subjective functioning, as well as to examine the role of social support.     

In vitro and in vivo activity of murine lymphokine-activated killer cells after cryopreservation

The in vitro and in vivo effects of cryopreservation on the cytotoxic activity of murine lymphokine-activated killer (LAK) cells were studied. LAK cells were generated by incubation of spleen lymphocytes of BALB/c mice for 3 days with recombinant interleukin-2 (rIL-2) and subsequent cryopreservation. Cytotoxicity was determined in a 51Cr release assay. After thawing, cytotoxic activity was reduced (40.4% 51Cr release at an effector:target cell ratio of 40:1 as compared to 68.5% 51Cr release before freezing) and could be restored to precryopreserved levels by reincubation with rIL-2 for 2 days after thawing (78.8% 51Cr release). These cells were then tested in BALB/c mice injected with RAW 112 cells, a pre-B-cell lymphoma line. The results demonstrate that the survival rate of mice injected with cryopreserved and restimulated LAK cells (50% survival greater than 180 days after injection) did not differ significantly from that of mice injected with fresh unfrozen LAK cells (60% survival greater than 120 days, 50% survival greater than 180 days). Cryopreserved LAK cells have potential use in adoptive immunotherapy.