[Effects of immunohistochemical conditions on the results of PD-L1 (22C3) staining].

Objective: To investigate the optimal experimental conditions (including antigen retrieval time, antibody titers and antibody incubation time) for reliable detection of programmed death-ligand 1 (PD-L1) expression using PD-L1 (22C3) antibody concentrate, and to establish a laboratory developed test for PD-L1 detection. Methods: Using Dako PD-L1 IHC 22C3 pharmDX staining procedure and scoring guidelines as the standard reference (group A), the PD-L1 expression in 25 tissue specimens (including 15 lung cancer tissues, 5 tonsil tissues and 5 placenta tissues) was detected with Flex+/HRP detection kit (EnVision) under 8 different experimental conditions (groups B1 to B8). The staining results were then compared to those in group A. Results: In group B1, 3 tissue samples showed the percentages of PD-L1 positive tumor cells were similar to those in group A, while the percentages of PD-L1 positive tumor cells were lower than those in group A in the other samples. In group B7, two case showed a positive rate higher than that in group A that was also above the positive cut-off value, and the rest of the samples had a percentage of PD-L1 positive tumor cells slightly higher than that in group A, but still below the positive cut-off value. The staining results of group B8 were the closest to those of group A compared with the other groups. Although the percentages of PD-L1 positive tumor cells in the B2 to B6 groups were decreased in various degrees as compared with group A, they were still concordant with group A's classification (positive vs. negative) and would not change the choice of clinical treatments. Conclusions: The experimental conditions are associated with detection rate of PD-L1 expression using 22C3 antibody. In the present study, the most-suitable alterative conditions in the PD-L1 detection using 22C3 antibody concentrate are those applied in the group B8 (including antigen retrieval in Dako PT Link tank at 97 ℃, pH 6.0 for 40 min and incubation with 22C3 antibodies (1∶100 dilution) at room temperature for 60 min, incubation with EnVision Flex+Linker at room temperature for 30 min, incubation with EnVision/HRP at room temperature for 30 min and DAB staining for 5 min), which could provide reliable results at minimum costs.

[Expression of pSTAT3 and PD-L1 in extranodal NK/T cell lymphoma and its clinical significance].

Objective: To study the expression of phosphates signal transducer and activator of transcription 3 (pSTAT3) and programmed death ligand-1 (PD-L1) in extranodal NK/T cell lymphomas (ENKTCL) and the relationships of pSTAT3 and PD-L1 expression with the clinicopathological characteristics and prognosis of ENKTCL. Methods: Fifty-one cases of ENKTCL diagnosed at Guangdong Provincial People's Hospital from June 2015 to February 2019 were included in the study. The expression of pSTAT3 and PD-L1 was examined using immunohistochemistry. Results: There were 35 males and 16 females, ranging from 18 to 85 years old with a median age of 47 years. The positive rates of pSTAT3 and PD-L1 expression were 68.6% (35/51) and 76.5% (39/51), respectively. pSTAT3 expression was correlated with PD-L1 expression (P=0.033,R=0.322), while there were no associations of pSTAT3 and PD-L1 expression with the clinicopathological characteristics of ENKTCL, including age, sex, clinical site, B symptom, Ann Arbor stage, LDH value, EBV DNA load of peripheral blood and international proliferation index score. Kaplan-Meier survival analysis showed the prognoses of the pSTAT3 and PD-L1 positive groups were slightly better than the respective negative groups, but the differences were not significantly (P>0.05). Conclusions: pSTAT3 is highly expressed in extranodal NK/T cell lymphoma and related to the expression of PD-L1, which provides a potential target and rationale for combinations of targeted therapies and immune checkpoint blockade inhibitors in the treatment of ENKTCL.

[Clinicopathological features of primary cardiac CD5-positive and bcl-2 and C-MYC double expression diffuse large B-cell lymphoma].

Objectives: To investigate the clinicopathological features, therapy and prognosis of primary cardiac CD5-positive diffuse large B-cell lymphoma with C-MYC and bcl-2 double expression. Methods: Two cases diagnosed at Guangdong Provincial People's Hospital were included, the clinical data were collected; the tumor morphology, immunophenotypic profiles, therapy and prognosis were analyzed. Results: Case 1 was a 55-year-old man and case 2 was a 61-year-old women. Intraoperatively, both cases showed large masses in the right atrium or ventricle, involving adjacent tissue. Pathologically, the tumors were composed of diffusely infiltrating large lymphoid cells with high mitotic activity and apoptosis. The tumor cells were positive for CD20, CD5, bcl-6, MUM1, C-MYC and bcl-2, and the Ki-67 index was equal or greater than 90%. Case 1 had bcl-6, but not bcl-2 or MYC gene rearrangements. No MYC, bcl-2 or bcl-6 gene rearrangements were detected in case 2. Case 1 defaulted chemotherapy after operation and died 1 month after diagnosis. Case 2 was treated with 4 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) therapy after surgery and attained partial remission, and was then treated with apatinib and ibrutinib, and remained stable 18 months after initial diagnosis. Conclusion: Primary cardiac CD5-positive diffuse large B-cell lymphoma with C-MYC and bcl-2 double expression usually shows large infiltrative mass in the right atrium or ventricle, non-germinal center like immunophenotype and high proliferation index, and this may contribute to the aggressiveness of primary cardiac lymphoma.

[Pathological features of duodenal-type follicular lymphoma].

Objective: To investigate the clinicopathological features, treatment and prognosis of duodenal-type follicular lymphoma. Methods: Four cases of duodenal-type follicular lymphoma diagnosed at Guangdong General Hospital from 2014 to 2015 with detailed clinical data were included. The histomorphology, immunophenotype, treatment and prognoses were analyzed. Results: The patients' age ranged from 51 to 57 years (mean 54 years), and there were 2 males and 2 females. The involved sites were gastric fundus in one case, second portion of the duodenum in two cases and terminal ileum in one case. All patients presented with multiple mucosal granules or nodules at endoscopy. Microscopically, there were multiple mucosal neoplastic follicles, constituting grade 1-2 disease based on nodal follicular lymphoma grading system. The tumor cells were positive for CD20, CD10, bcl-6 and bcl-2. CD21 highlighted the follicular dendritic meshwork mainly at the periphery of the follicles. Proliferation index was low. Three patients received rituximab monotherapy for 4 cycles, leading to complete remission. One patient refused therapy and the disease progressed to systemic lymphoma 15 months after the initial diagnosis. Conclusions: Duodenal-type follicular lymphoma is a special variant of follicular lymphoma with indolent clinical course. The tumor exhibits morphology of low grade follicular lymphoma with characteristic dendritic meshwork at the periphery of the follicles and a low proliferation index. Prognosis is excellent. Rituximab monotherapy is treatment of choice, but a small minority of patients may progress to systemic disease.

[Expression of ßF1 and T cell receptor γ in T lymphoblastic lymphoma/leukemia].

Objective: To evaluate the expression of ßF1 and T cell receptor (TCR)γ in T lymphoblastic lymphoma/leukemia(T-LBL/ALL), and investigate the clinicopathological features. Methods: Fifty-one cases of T-LBL/ALL were collected at Guangdong General Hospital from 2010 to 2016, the expression of ßF1 and TCRγ was assessed by immunohistochemistry. Results: There were 13 cases of children and adolescents, and 38 cases of adults. The expression rates of ßF1 and TCRγ were 27.5%(14/51) and 15.7%(8/51) respectively. The proportion of adults in αß T-LBL/ALL, TCR-silent T-LBL/ALL and γδ T-LBL/ALL was 7/14, 79.3%(23/29)and 8/8 respectively, and the difference was significant (P=0.023). There was no statistical difference in sex, LDH, bone marrow involvement and Ann arbor stage among these three groups(P>0.05). γδ T-LBL/ALLs included 6 cases of CD4(-)/CD8(-) phenotype, whereas αß T-LBL/ALL included 7 cases of CD4(+) /CD8(+) phenotype. There was significant difference in CD4/CD8 expression among these three groups(P<0.01). Conclusions: γδ T-LBL/ALL occurred only in adults, with predominantly CD4(-)/CD8(-) phenotype. αß T-LBL/ALL occurred more common in children and adolescents, with predominantly CD4(+) /CD8(+) phenotype.

[Progress in knowledge-based X-ray fluorescence spectrometry].

The review focuses on the expert systems and knowledge engineering in X-ray fluorescence spectrometry. It includes mainly a knowledge-controlled strategy combining the scan-based method with the fixed channel measurements, a XRF interpretation system of spectra with fuzzy logic and pattern recognition, and an expert system for qualitative interpretation of XRF spectra using a certainty factor. In the review, a series of the studies of exploring the knowledge engineering system in XRF are also included, which consists of four parts, i.e. spectra identification, pattern recognition with decision-making, quantitative determination combined with the theoretical alpha coefficients and neural networks, and XRF analysis without standards.

[Enhanced metastasis of a mouse mammary adenocarcinoma after in vitro treatment with gamma-interferon].

gamma-Interferon (IFN-gamma) was detected by ELISA assay in ascitic fluid from a number of ovarian cancer patients. To study its clinical significance, the effect of IFN-gamma on the metastatic potential of a mouse mammary adenocarcinoma, MA-891, was explored. Pretreatment of the tumor cells in vitro for 48hr with recombinant INF-gamma significantly increased the number of lung tumor nodules after i. v. or s. c. inoculation into (TA2 x 615) F1 mice. In contrast, when recombinant IFN-alpha pretreated MA-891 cells were likewise injected into mice significant decrease in metastatic potential was seen. The study in vitro indicated that pretreatment of the tumor cells with IFN-gamma but not with IFN alpha resulted in a decrease in susceptibility to NK cell cytotoxicity. In as much as both IFN-alpha and IFN-gamma can induce MHC class I expression on target cells. The increase in metastatic potential of IFN-gamma-treated tumor cells can be explained only partially on the basis of their reduced NK cells susceptibility.

[Observation of the in vivo tumor cell lysis mediated by NK cells].

Natural killer cells/large granular lymphocytes (NK/LGL) separated on discontinuous Percoll gradient from rat spleen cells were injected iv to rats (7 x 10(7) cells/rat) 3 days following iv inoculation of 2 x 10(6) Walker-256 cells. Two and 4 hr after NK/LCL injection, animals were sacrificed and the lungs examined by light and immunoelectron microscopy. The latter was done using colloidal gold-labelled polyclonal antibody against purified rat LGL cytoplasmic granules. At 2 hr following iv NK/LGL, in addition to the scattered individual tumor cells and minute tumor foci, many lymphocytes were seen accumulating in the small pulmonary vessels and capillaries. This was not observed in tumor-inoculated control rats. At 4 hr, many extravasated lymphocytes reached the lung parenchyma, some of which had attached to the tumor cells. Immunoelectromicroscopically, lymphocytes were found in intimate contact with the tumor cells with the cytoplasmic gold particles clustering at the cell contact site. Gold particles could also be seen closely adherent to the plasma membrane of degenerating tumor cells. This is the first in vivo demonstration of the role of cytotoxic granules of NK cells in tumor cell lysis.

Identification, secretion, and neural expression of APPL, a Drosophila protein similar to human amyloid protein precursor.

A Drosophila gene [amyloid protein precursor-like (Appl)] has recently been identified whose predicted amino acid sequence (APPL) shares extensive homology with the beta-amyloid protein precursor (APP) associated with Alzheimer's disease. Characterization of proteins encoded by the Appl gene was initiated with the expectation that this simple model system might help elucidate the basic function provided by APPL and APP proteins. In this report, we identify 2 forms of the APPL protein in embryonic extracts, primary cultures, and transfected cells. APPL is synthesized as a 145-kDa membrane-associated precursor that is converted to a 130-kDa secreted form that lacks the cytoplasmic domain. Both forms are N-glycosylated. Pulse-chase and subcellular localization studies suggest that the conversion is very rapid. The similarities of biogenesis between APP and APPL provide further evidence that APPL and APP might be functionally homologous, and that the secretion event is of physiological significance. Immunocytochemical studies show that the APPL proteins are first detected in developing neurons concomitant with axonogenesis and remain associated with differentiated neurons. APPL immunoreactivity was observed in neuronal cell bodies, axonal tracts, and neuropil regions. In the embryo, APPL proteins are expressed exclusively in the CNS and PNS neurons, consistent with the Appl transcript localization. The expression pattern of APPL proteins suggests an ancestral function for this protein in the nervous system.

A Drosophila gene encoding a protein resembling the human beta-amyloid protein precursor.

We have isolated genomic and cDNA clones for a Drosophila gene resembling the human beta-amyloid precursor protein (APP). This gene produces a nervous system-enriched 6.5-kilobase transcript. Sequencing of cDNAs derived from the 6.5-kilobase transcript predicts an 886-amino acid polypeptide. This polypeptide contains a putative transmembrane domain and exhibits strong sequence similarity to cytoplasmic and extracellular regions of the human beta-amyloid precursor protein. There is a high probability that this Drosophila gene corresponds to the essential Drosophila locus vnd, a gene required for embryonic nervous system development.

Properties of NAD glycohydrolase purified from five-pace snake (Agkistrodon acutus) venom.

NAD glycohydrolase (NADase) (E.C. 3.2.2.5) from five-pace snake (Agkistrodon acutus) venom was purified to electrophoretic homogeneity through a 4-step isolation procedure, including column chromatography using DEAE-Sephadex A-50, Sephadex G-75, CM Sephadex C-50 and Sephadex G-100. The final product was 11.8-fold purified with a 3.9% yield. The pure enzyme showed maximal activity at about 40 degrees C with optimal pH at 7.5. It was a glycoprotein with a pI of 7.6. Its mol. wt was respectively 98,000 as measured by gel filtration and 50,000, by SDS-PAGE. There was only one N-terminal residue, proline. NADase is thus composed of two identical subunits in each molecule. The enzyme contained copper ions. NADase activity was lost when the copper enzyme complex was treated with EDTA. The Km of the enzyme for beta-NAD, NADP and beta-NGP were 0.50 mM, 0.13 mM and 0.16 mM respectively.