Hemopoiesis in long-term stroma-dependent cultures from lymphoid tissue: production of cells with myeloid/dendritic characteristics

A long-term stroma-dependent culture system (LTC) has been developed which continuously produces hemopoietic cells providing an in vitro system for the study of cell differentiation. These nonadherent cell populations contain a large subpopulation of dendritic cells (DC). LTC producing DC were easily generated from spleen, but could also be established from bone marrow (BM) and lymph node with less success. It was difficult to establish DC-producing LTC from thymus. The properties of splenic and thymic stroma have been compared. Spleen stroma developed more complicated networks of fibroblasts, endothelial cells, macrophages, and DC. Thymic stromal monolayers were dominated by epithelial cells and fibroblasts, with a lower proportion of macrophages and endothelial cells. They had a relatively sparse structure of cell networks compared with spleen stroma. Cells with dendritiform morphology first appeared in cultures by 2-3 wk. The majority of cells produced were large cells which expressed DC-specific cell surface markers, major histocompatibility complex (MHC) Class II molecules, and the CD80/CD86(B7) costimulator. A high proportion of cells also expressed myeloid cell markers. No T or B lymphoid cells or granulocytes were present in the cultures. LTC continued to produce nonadherent cells resembling myeloid/DC for long periods, even after passage of stromal cells and stem cells at about 3-4 mo. after culture establishment. The LTC system offers potential to study the in vitro differentiation of myeloid/DC.

Long-term stromal cultures produce dendritic-like cells

A stromal cell-dependent long-term culture (LTC) system has been developed from spleen which continuously generates non-adherent cells with dendritic cell (DC) characteristics. Bioassays using factor-dependent cell lines have revealed that both spleen and thymic stromal cultures secrete interleukin (IL)-3 and IL-6-like growth factors. Conditioned medium from LTC also contains factors which appear to be unrelated to IL-3 and induces growth of stromal cells from bone marrow. Non-adherent cells generated in LTC were not T or B lymphoid cells or granulocytes, nor were mast cells detectable. Morphological and electron microscopic examination has also excluded the presence of macrophages (Mo). Cells with DC morphology have been detected by both light and electron microscopy. The majority of cells in the non-adherent population were found to have multiple membrane pseudopodia, with a small acentric nucleus. These appear to be the precursors of DC. They expressed cell surface markers detectable with DC-specific antibodies and antibody specific for major histocompatibility complex Class II molecules. A proportion of cells also expressed myeloid markers, but since this expression was not supported by histochemical staining for myeloperoxidase or non-specific esterase, it was concluded that the cells produced are not typical of the myeloid lineage. Cells generated in LTC were shown to be potent stimulators for allogeneic and syngeneic MLR and for antigen-specific T-cell proliferation.

The role of dendritic cells in T cell activation

Dendritic cells (DC) are distinguishable from other antigen-presenting cells by their potent antigen-presenting capacity. They are not only efficient at presenting peptide antigen but can also process and present soluble protein antigen sto antigen-specific T cells and cloned T cell lines. They are very strong stimulators of both allogeneic and syngeneic mixed lymphocyte reactions and have a unique capacity to stimulate naive T cells. The potent functional capacity of DC is related to a high-level expression of major histocompatibility complex class I/II molecules and constitutive expression of costimulatory molecules, such as CD80/CD86, as well as heat stable antigen, CD40 and the leucocyte function antigen (LFA) family of adhesion molecules. Recent studies have shown that DC are also involved in regulation of the immune response via induction of both central and peripheral tolerance.

[The effect of tinidazole in the treatment of adult periodontitis]

Fifty-two adult periodontitis patients were treated by the tablets of tinidazole (TNZ), and 23 patients treated by metronidazole (MNZ) served as control group. The effective rate of TNZ in adult periodontitis patients was 73.1%, which was significantly higher than that of the control group (43.5%). Antimicrobial studies showed that the capability of TNZ to kill the periodontal dominant anaerobic bacteria, especially B. gingivalis and B. melaninogenicus, was better than that of MNZ. The minimal inhibitory concentration (MIC) of TNZ to Bacteroides, Fusobacterium, Veillonella, Eubacterium, Antinomyces, Peotostreptococus and Anaerobic Streptococus was lower than that of MNZ and actylspiramycine.

Schwannoma with metastatic carcinoma of the breast: an unconventional form of glandular peripheral sheath tumor

We report a schwannoma of the left arm harboring metastatic adenocarcinoma in a 68-year-old woman who had a history of invasive ductal carcinoma of the left breast with widespread metastases. The soft tissue tumor of the left arm had the morphological features of a typical schwannoma except for the presence of multiple foci of moderately to poorly differentiated adenocarcinoma and a grossly visible cyst that was lined by benign appearing cuboidal to low columnar epithelium. The immunohistochemical studies showed that the spindle cells were diffusely and strongly positive for vimentin, S-100 protein, and collagen type IV, and focally reactive for Leu 7. The cyst and the foci of adenocarcinoma were both stained for cytokeratin, but the adenocarcinomatous foci also were immunoreactive for estrogen receptor, gross cystic disease fluid protein, and focally for S-100 protein, in contrast to the lack of positivity for these three markers in the epithelium of the cyst. To the best of our knowledge this case is a unique one of a schwannoma with metastatic mammary carcinoma producing yet another variation on the theme of a glandular peripheral nerve sheath tumor.

Fine needle aspiration of mammary carcinoma with features of a carcinoid tumor. A case report with immunohistochemical and ultrastructural studies

We report a case of fine needle aspiration (FNA) of a mammary carcinoma with features of a carcinoid tumor from the right breast of an 87-year-old woman who had a history of a left mammary "carcinoid" tumor diagnosed histologically three years earlier. Aspiration cytology revealed extremely rich cellularity. The neoplastic cells were mostly dispersed; however, they also could be found in loose clusters, acinus-like formations and occasionally in small sheets. They were relatively small and regular and contained fairly uniform, mostly round and oval nuclei with moderately abundant cytoplasm. Many of the tumor cells had eccentric nuclei. Immunohistochemical study revealed that tumor cells from both the cytologic smear and histologic section were reactive with antibody against serotonin. Ultrastructural study performed on the simple right mastectomy specimen showed many membrane-bound, dense-core particles in the cytoplasm of neoplastic cells, consistent with neuroendocrine secretory granules.

Characterization of unique lymphoid cells derived from murine spleen which constitutively produce interleukin-6

Attempts have been made to isolate continuous lines of rare subsets of lymphoid cells present in murine spleen in order to analyse their function and lineage relationship with respect to other lymphoid cells. Mitogenic stimulation was used to expand the lymphoid cells remaining in spleen following depletion of CD4+ and CD8+ T cells by antibody and complement treatment. Cells were cultured in the presence of concanavalin A (Con A), interleukin-2 (IL-2) and syngeneic irradiated spleen feeder cells. This procedure expanded a population of non-T-, non-B-lymphoid cells bearing a common, unique phenotype resembling lymphoid precursors. Eight cloned lines from B10.A(2R) and B10.A(5R) strains of mice have been analysed here. Analysis of cell surface marker expression has revealed positive expression of class I and class II major histocompatibility complex (MHC) antigens, CD44, CD45 (T200 and B220) but expressing no markers unique to T, B or myeloid cells. All cell lines represent agranular lymphoblasts and show no evidence of early T-cell receptor (TcR) or Ig heavy chain gene rearrangements, suggesting no commitment to T-or B-lymphoid lineage. Despite expression of the NK1.1 marker for natural killer (NK) cells, none of the cell lines has been shown to have cytotoxic function for NK targets, nor could cytotoxic function be induced following various activation procedures. Analysis of lymphokine production has revealed no detectable IL-1, IL-2, IL-3, IL-4, IL-5, tumour necrosis factor-alpha (TNF-alpha) or granulocyte-macrophage colony-stimulating factor (GM-CSF) in cell supernatants. However, all but one of these cell lines constitutively produce IL-6. Each cell line has been shown to induce T-cell proliferation independently in mixed lymphocyte reactions, implicating the capacity of these cells to act as antigen-presenting cells. Consistent with this hypothesis is the observation that these cells also demonstrate endocytic activity for foreign proteins. This was visualized by their uptake of fluoresceinated albumin into cytoplasmic granules. Since they express many cell surface markers common to described isolates of spleen dendritic cells, including both class I and class II major histocompatibility molecules, they would appear to represent the first example of continuous lines of this rare cell subset.

Proliferation of the BCL1 B cell lymphoma induced by IL-4 and IL-5 is dependent on IL-6 and GM-CSF

Lymphokine requirements for the in vitro proliferation of the spleen-dependent B cell lymphoma BCL1 have been analysed. Cells were found to respond by proliferation to added recombinant (r) interleukin-4 (IL-4), r-IL-5 and recombinant granulocyte-macrophage colony-stimulating factor (r-GM-CSF). Inhibition by antibodies specific for each of these lymphokines has confirmed growth factor-dependent growth. Anti-GM-CSF has, however, been found to inhibit the proliferation of BCL1 cells induced by r-IL-4 and r-IL-5, as well as r-GM-CSF, suggesting that BCL1 cells may express receptors for GM-CSF and that GM-CSF may be able to act synergistically with IL-4 and IL-5 in promoting cell proliferation. Anti-IL-6 antibody was also found to be a very effective inhibitor of BCL1 proliferation induced by either IL-4 or IL-5 but not by GM-CSF. Added IL-6 did not stimulate BCL1 proliferation, suggesting that endogenous IL-6 may regulate the autocrine growth of BCL1 cells. BCL1 cell proliferation in vitro appears to be regulated by interactions between multiple growth factors.

Lymphoid precursor cell lines have capacity to migrate to multiple lymphoid sites

Cell lines have been isolated which phenotypically resemble natural killer (NK)/lymphoid precursor cells. These cell lines were derived by in vitro culture and represent continuously replicating cell lines. Since they do not grow as tumours in vivo, it was anticipated that they may have maintained the migratory capacity of their normal cell counterpart. Capacity to migrate to various lymphoid sites, i.e. spleen, bone marrow, thymus and mesenteric lymph node, has been analysed in a short-term 3-hr homing assay following intravenous injection of cells into a syngeneic irradiated host. Frequency of cells localizing in these organs was estimated by limit dilution cloning analysis. Three out of four cell lines were found to migrate to all four organs, while the C6VL/1 T-cell lymphoma was detected in spleen and bone marrow only, and did not enter thymus and mesenteric lymph nodes. This suggests that NK/lymphoid precursor cells may exist which have capacity to recirculate widely through the lymphoid system.

Comparison of estrogen receptor immunocytochemical assay in frozen and paraffin sections

Frozen and paraffin sections of 11 breast carcinomas were stained for estrogen receptors (ER) using the same rat monoclonal primary antibody, D75P3, as the marker and alkaline phosphatase as the chromogen-linking enzyme. The results of this staining process were assessed visually and with the microTICAS image analysis system to determine the degree of correlation between frozen and paraffin-embedded tissue. In all specimens, some fraction of the nuclei stained positively. This included two specimens selected for their biochemically negative assay; one of them stained strongly positively with D75P3. The results of quantitative analysis support the visually apparent correlation between the two types of samples in terms of both overall staining pattern and intensity of nuclear staining. Although the conclusions of this pilot study are limited because of the small number of cases, this method of staining establishes the feasibility of representative ER determination in archival paraffin-processed material. The additional information provided by this method is potentially useful in stratifying patients in prospective studies on the basis of the efficacy of hormonal therapy in biochemically ER positive breast tumors.

Chemotherapy-related hemolytic-uremic syndrome after the treatment of head and neck cancer. A case report

A 62-year-old woman who was being treated for squamous cell carcinoma of the head and neck developed a chemotherapy-related hemolytic-uremic syndrome during the second cycle of neoadjuvant chemotherapy consisting of cisplatin, bleomycin, and methotrexate. Though the syndrome was suspected early, attempts at reversing the hematologic and renal abnormalities were unsuccessful. At postmortem examination, the characteristic microvascular lesions of the hemolytic-uremic syndrome were found in the kidneys.

Disseminated adenovirus infection with hepatic necrosis in patients with human immunodeficiency virus infection and other immunodeficiency states

Disseminated adenovirus infection with fatal hepatic necrosis has been reported in 16 patients, 15 of whom had immunocompromising conditions. Herein we report three patients with AIDS and fatally disseminated adenovirus infection with hepatic necrosis. The median age of these 16 patients was 4.7 years, and their illness was characterized by fever (13 of 16 patients), coagulopathy (10 of 16), lower respiratory tract disease (10 of 16), and gastrointestinal hemorrhage (five of 16) in addition to clinical evidence of hepatitis. The adenoviruses isolated were the commonly found serotypes 1, 2, 3, 5, and 7 for 13 of the 15 cases for which this determination was available. With the high frequency of adenovirus infection in humans and the increasing prevalence of human immunodeficiency virus infection in children, it seems likely that this syndrome will continue to be seen.