Immunohistochemical study of hepatic oval cells in human chronic viral hepatitis

AIM: To detect immunohistochemically the presence of oval cells in chronic viral hepatitis with antibody against c-kit. METHODS: We detected oval cells in paraffin embedded liver sections of 3 normal controls and 26 liver samples from patients with chronic viral hepatitis, using immunohistochemistry with antibodies against c-kit, piclass glutathione S-transferase (pi-GST) and cytokeratins 19 (CK19). RESULTS: Oval cells were not observed in normal livers. In chronic viral hepatitis, hepatic oval cells were located predominantly in the periportal region and fibrosis septa,characterized by an ovoid nucleus, small size,and scant cytoplasm. Antibody against stem cell factor receptor, c-kit, had higher sensitivity and specificity than pi-GST and CK19. About 50%-70% of c-kit positive oval cells were stained positively for either pi-GST or CK19. CONCLUSION: Oval cells are frequently detected in human livers with chronic viral hepatitis, suggesting that oval cell proliferation is associated with the liver regeneration in this condition.

Possibility of non-invasive diagnosis of gastric mucosal precancerous changes

AIM: To assess the possibility of non-invasive screening of atrophic chronic gastritis for preventing further development of gastric cancer.METHODS: One hundred and seventy-eight consecutive Helicobacter pylori ( H pylori)-positive dyspeptic patients after detection of serum levels of pepsinogen-1 (PG-1) and gastrin-17 (G-17) by enzyme immunoassay were proposed for endoscopy and histology. The serologic and morphologic results were compared with estimating the sensitivity, specificity and prognostic values of the tests.RESULTS: There was statistically significant reverse dependence between the grade of stomach mucosal antral or corpus atrophy and the proper decreasing of serum G17 or PG1 levels. The serologic method was quite sensitive in the diagnosis of non-atrophic and severe antral and corpus gastritis. Also, it was characterized by the high positive and negative prognostic values.CONCLUSION: Detection of serum G-17 and PG1 levels can be offered as the screening tool for atrophic gastritis. The positive serologic results require further chromoendoscopy with mucosal biopsy, for revealing probable progressing of atrophic process with development of intestinal metaplasia, dysplasia or gastric cancer.

Determination of low level HBsAg in serum by microparticle enzyme immunoassay

Objective: To investigate the distribution of the popula- tion with iow level HBsAg in serum and the characteri- stics of their HBV serologic markers. Methods: We detected HBsAg, HBeAg, anti-HBc, an- ti-HBe, and anti-HBs in the serum samples from 8089 non-hepatitis inpatients and defined the patients with HBsAg concentration equal to or less than 5 μg/L by using the AxSYM microparticle enzyme immunoassay (MEIA) system. Results: 189 patients with HBsAg equal to or Iow than 5 μg/L (2.34% of all 8089 patients and 23.16% of 816 HBsAg positive patients) included 84 (44.40%), 33 (17.5%) and 72 (38.10%) with HBsAg equal to or less than 1 μg/L, 1-2 μg/L and 2-5 μg/L respec- tively. Most of these patients were detected with 'posi- tive for HBsAg, anti-HBc and anti-HBe but negative for HBeAg and anti-HBs', and anti-HBc antibodies were frequently present in their sera. Conclusions: The population with low Level HBsAg in serum should not be neglected and it is important to improve the test sensitivity of HBsAg and to detect the other HBV serologic markers.

An experimental study of pioglitazone in treating vascular dementia

Objective To compare the therapeutic effects of different doses of pioglitazone,a kind of peroxisome proliferator-activated receptor γ(PPARγ)agonist,on vascular dementia and explore how pioglitazone affects cerebral ischemia.Methods Modified Pulsinelli’s vessel ligation was used to establish a vascular dementia model in rats.Recognition,learning and memory were evaluated by Morris’s water maze test.Immunoenzyme staining was used to determine the number of nerve cells.Immunofluorescence double-staining was used to examine the expression of PPARγ/nerve cells and PPARγ/astrocytes in different groups.Results Both in pioglitazone groups and sham-operation group,the latency was reduced significantly compared to that in control group(P<0.01).Sham-operation group had the largest number of neurons in the cortex,followed by low-dose pioglitazone group and high-dose pioglitazone group,and control group came last.Compared with control group,pioglitazone groups had more PPARγ expression in nerve cells,and the fluorescence intensity of PPARγ was stronger.Conclusion Pioglitazone can induce the expression of PPARγ in neuron endochylema and astrocyte endochylema to protect nerve cells,and then to improve spatial learning and memory function in VD rats.

Quantitative observation by enzyme cytochemistry of human rectal adenocarcinoma cells killed by LAK cells

Activity of succinic dehydrogenase(SDH)and acid phosphatase(AcPase)of effector-target cells during the process of LAK cells killing HR8348 cells was estimated by enzyme cyto-chemistry technique.SHD positive granules and AePase gray level were assayed with MIAS-300image analyser.The results showed:(1)After cocultivation of effector and target cells for vari-ous times,the activity of AcPase of HR8348 cells was apparently higher than that of the controlgroup,and it increased following prolonged coincubation.SDH activity of target cells increasedmarkedly within 30 and 60 rain cocultivation,but became low after 90 min treatment.(2)Ac-Pase content within LAK cells at 60,90,120,180 and 240 rain cocultivation was significantlyhigher than that of control group(P【0.01).The phenomenon of high AcPase and SDH activitywithin effector-target cells indicates that the function of the two types of cells was in an activestate.At the early stage of effector-target combining,the increase of SDH with HR8348 cellsmay be related to defensive function of the target cells.Higher AcPase activity of target cells in-dicates the activation of lysosomal enzyme which serves as the material basis for autolysis of thecells.

THE APPLICATION OF IMMUNOHISTOCHEMISTRY IN THE DIFFERENTIAL DIAGNOSIS OF EXTRANODAL LYMPHOMA AND ANAPLASTIC CARCINOMA

Thirty-six cases originally diagnosed histologically as malignant lymphoma (ML) or anaplastic carcinoma were reexamined immunohistochemically by leukocyte common antigen (LCA) and epithelial membrane antigen (EMA). 5/18 cases originally diagnosed as ' anaplastic carcinoma'' and 'anaplastic carcinoma? (ML to be excluded)' , showed positive staining for LCA and negative for EMA; whereas 3 cases originally diagnosed as malignancy unclassified turned out to be ML, with the relevant assay performed.