DETECTION OF OCCULT TUMOR CELLS IN RESECTED LYMPH NODES OF PATIENTS WITH STAGE I CARCINOMA AND ITS CLINICOPATHOLOGICAL SIGNIFICANCE

Objective: A lot of 3715 resected lymph nodes from 350 stage I cancer patients, including 94 NSCLC, 112 breast carcinoma, 115 esophageal carcinoma, and 29 vulvar carcinoma cases, were re examined by immuno histochemistry. Methods: Using monoclonal anti cytokeratins (AE1/AE3), anti EMA, and polyclonal anti keratin antibodies, the tumor cell micrometastases were detected to obtain more reliable information concerning the nodal status. Results: Nodal occult metastases were observed in 113 of 350 (32.5%) patients and in 203 of 3715 (5.5%) nodes. The positive rates in both patients and nodes were higher in NSCLC than in others (P<0.05). The nodal occult metastases were seen in 58% of pulmonary squamous cell carcinoma and 53.8% of adenocarcinoma, while they were seen in 22.5% of esophageal and 10.3% of vulvar squamous cell carcinomas and in 27.7% of breast adenocarcinoma (P<0.05). Follow up of a part of breast carcinoma patients showed that the clinical prognosis was worse in patients with positive nodes than in negative ones (P< 0.05 ). Conclusion: The data suggested that the immunohistochemical techniques can significantly facilitate the detection of micrometastatic tumor cells in lymph nodes. The frequency of nodal occult metastases may have important impact on the clinical prognosis of cancer patients.

STUDY ON EXPRESS OF a-HCG AND a-HCGmRNA IN PANCREATIC ENDOCRINE TUMORS

The antigen Alpha subunit of human chorionic gonadotropin (α HCG) and a HCGmRNA in pancreatic endocrine tumors (PET) were investigated by immuno histochemistry and in situ hybridization. It was found that α HCG can be detected in PET buy not in normal islet cells. α HCG immunoreactivity was expressed by 5 of 28 (18%) in benign PET and 14 of 24 (58.3%) in malignant PET. Using in situ hybridization of α HCGmRNA, a strong signal in PET was obtained. The clinico pathological significance of α HCG in PET was discussed.

Cytopathic effects and local immune responses in repeated neoadjuvant HSV-tk+ ganciclovir gene therapy for prostate cancer

Objective:Cytopathic effects and local immune response were analyzed histologically in prostatic cancer(PCa)with in situ herpes simplex virus-thymidine kinase(HSV-tk)/ganciclovir(GCV)gene therapy(GT).Methods:Four high-risk PCa patients who received HSV-tk/GCV GT were investigated.After two cycles of intraprostatic injection of HSV-tk and administration of GCV,radical prostatectomy was performed.Formalin-fixed,paraffin-embedded sections were evaluated using immunohistochemistry.PCa with hormone therapy(HT,n=3)or without neoadjuvant therapy(NT,n=4)that were equivalent in terms of risk were also examined as reference.Immunoreactively-positive cells were counted in at least three areas in cancer tissue.Labeling indices(LI)were calculated as percentage values.Results:ssDNA LI in GT increased,indicating apoptosis,as well as tumor-infiltrating lymphocytes and CD68-positive macrophages,compared with their biopsies.GT cases showed significantly higher numbers of single-stranded DNA(ssDNA)LI,CD4/CD8-positive T cells and CD68-positive macrophages including M1/M2 macrophages than HT or NT cases.However,there was no significant difference in CD20-positive B cells among the types of case.There were strong correlations between CD8+T cells and CD68+macrophages(ρ=0.656,p<0.0001)as well as CD4+T cells and CD20+B cells(ρ=0.644,p<0.0001)in PCa with GT.Conclusions:Enhanced cytopathic effect and local immune response might be indicated in PCa patients with HSV-tk/GCV gene therapy.

Experimental infection with Yersinia pseudotuberculosis in European brown hare(Lepus europaeus,Pallas)

Objective:To investigate clinicopathological,bacteriological and pathological aspects of an experimental infection with Yersinia pseudotuberculosis(Y.pseudotuberculosis)in hares in order to verify the efficacy of serology for the in vivo diagnosis.Moreover,the pathogenicity of two Y.pseudotuberculosis strains was investigated in order to detect potential differences.Methods:Twelve European brown hares(Lepus europaeus,Pallas)were experimentally infected per os and via conjunctival mucosae with Y.pseudotuberculosis:six subjects were infected with a strain isolated from a naturally infected hare(YpH)and six subjects with a strain isolated from a naturally infected rabbit(YpR).Two hares were used as negative controls.All animals were subjected to clinical,bacteriological and serological examinations during 9 weeks following the infection and,at the end of the control period,subjects still alive were euthanized and submitted to a complete post mortem examination.Results:All faecal samples collected during the control period were positive for bacteriological examinations and to a PCR for the inv gene of Y.pseudotuberculosis,while only one Yp H-infected hare showed a positive haemocultures.From the 2nd to the 9th week post infection(pi),serological analysis revealed specific antibodies with titers ranging from 1:10 to 1:160 in all YpH-infected and two YpR-infected subjects.All the Yp H-infected and two Yp R-infected hares scored positive for Y.pseudotuberculosis by means of bacteriological investigations.Grossly,suppurative multifocal lesions were detected in liver,spleen,kidney and sub-mandibular lymph nodes in both YpH-and YpR-infected hares and confirmed with histopathology.Pulmonary lesions were observed only in Yp H-infected subjects.Immunohistochemistry confirmed the presence of bacterial antigen in all infected animals.Conclusion:Results of this study revealed that YpH strain is more pathogenic for hares than the YpR strain;moreover the serological test performed in this study could be used for the diagnosis of pseudotuberculosis in hares,whereas post mortem diagnosis should be confirmed by means of bacteriological examination,PCR,histopathology and immunohistochemistry.