Cytological features of solid variants of papillary thyroid carcinoma: a fine needle aspiration cytology study of 18 cases.

OBJECTIVE: Solid variants of papillary thyroid carcinoma (SV-PTC) are rare, and there have been few reports describing the cytological findings of such variants. METHODS: The cytological features of cellular specimens aspirated from 18 histologically confirmed SV-PTC cases were evaluated, retrospectively. RESULTS: Solid and small papillary clusters were observed in 14 (77.8%) and 13 (72.2%) cases, respectively. The incidences of large papillary clusters (11.1%) and sheet-like arrangements (11.1%) were low. Nuclear features were consistent with conventional PTC. The background was clean, and there were no colloid materials, foamy histiocytes, multinucleated giant cells, psammoma bodies, or necrotic materials. CONCLUSIONS: Solid clusters and small papillary clusters in conjunction with a clean background are diagnostic clues that indicate SV-PTC cytologically. It is thought that small papillary clusters reflect the micropapillary growth pattern seen within the lumen of middle-sized follicular structures. The presence of nuclear findings typical of conventional PTC and the absence of mitotic figures and necrotic materials are important for distinguishing SV-PTC from poorly differentiated carcinoma.

Thyroid FNA cytology in Asian practice-Active surveillance for indeterminate thyroid nodules reduces overtreatment of thyroid carcinomas.

Although Asian thyroid practices have implemented the American Thyroid Association guidelines, significant deviations in actual risk of malignancy (ROM) have been reported. With review of the literature from Asia, the authors examine the underlining reasons for actual ROMs reported in Asia being so different from western practice based on the author's perspective. Although the most popular diagnostic system for thyroid cytology used in Asian countries is the Bethesda system, the Japan Thyroid Association published clinical guidelines, including a national reporting system for thyroid cytology, to adapt conservative clinical management (active surveillance and strict triage patients for surgery) for low-risk thyroid carcinomas. As less aggressive clinical management is favoured in Asian societies, strict triage of patients with indeterminate thyroid nodules for surgery is usually applied, which ultimately reduces overtreatment of indolent thyroid tumours. As a result, low resection rates and high ROMs for indeterminate nodules were achieved in Asian practices using the same Bethesda system. Recently, borderline thyroid tumours were introduced in the thyroid tumour classification and significant decreases in ROMs have been reported in the indeterminate categories in western practice. However, ROM of indeterminate nodules remained high in Asian practice even after borderline tumours were deemed benign. These results suggested that the diagnostic threshold of papillary thyroid carcinoma-type nuclear features varied among practices (stricter in Asia than in western practice), and diagnostic surgery was not performed for a significant number of indeterminate nodules with benign clinical features in Asian practice, resulting in low rates of borderline tumours in surgically-treated patients.

Diffuse sclerosing variant of papillary thyroid carcinoma: a study of fine needle aspiration cytology in 20 patients.

BACKGROUND: A diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) is a rare variant and reports describing the cytological findings are few. PATIENTS AND METHODS: We studied 24 cytological samples from thyroid fine needle aspirates of 20 patients with DSV-PTC. The specimens were taken from 14 non-nodular lesions and 10 nodules. RESULTS: All aspirates taken from both non-nodular lesions and nodules had sufficient cellularity. The carcinoma cells frequently (70-100%) appeared as solid cell balls and hollow balls, and showed a hobnail pattern, squamous differentiation, septate cytoplasmic vacuoles and large unilocular vacuoles. Most of the carcinoma cells seem to be taken from the lumen of dilated lymph vessels. Ground glass nuclear chromatin, intranuclear cytoplasmic inclusions and grooved nuclei were infrequent (50% or less). In the background, a large number of lymphocytes and abundant psammoma bodies were almost always seen. CONCLUSIONS: Cytological findings of DSV-PTC are as follows: (1) solid cell balls and/or hollow balls containing lymphocytes; (2) hobnail cells; (3) septate cytoplasmic vacuoles; (4) large unilocular vacuoles; (5) squamous differentiation; (6) abundant psammoma bodies; (7) lymphocytic background; and (8) the absence or relative lack of characteristic nuclear features of papillary carcinoma. When DSV-PTC is suspected by ultrasound examination, the aspiration cytology from a non-nodular area of the thyroid can led us to the diagnosis of the variant.

The role of transforming growth factor beta in the generation of suppression: an interaction between CD8+ T and NK cells.

CD8+ T cells have suppressor effector functions, but the mechanisms involved in the generation of this activity are poorly understood. We report that natural killer (NK) cells have an important role in the acquisition of this function. CD8+ cells induce NK cells to produce transforming growth factor-beta (TGF-beta) which, in turn, stimulates CD8+ T cells to become suppressors of antibody production. Using a monocyte-dependent and -independent method to induce antibody production, we first observed that the addition of NK cells to CD8+ cells was required for optimal suppression. Next, we determined that the interaction of CD8+ T cells with NK cells resulted in a striking increase NK cell TGF-beta mRNA and its production. This cytokine appeared to be involved in the induction of T suppressor cell activity since: (a) anti-TGF-beta 1 completely abrogated the suppression of immunoglobulin G synthesis; (b) TGF-beta 1 could substitute for NK cells in inducing CD8+ T cells to develop suppressor activity; and (c) a short exposure of T cells to TGF-beta 1 in the absence of B cells was sufficient for the generation of suppressor activity by CD8+ T cells. Interferon gamma did not have this property. These studies provide strong evidence that in addition to its suppressive properties, TGF-beta is involved in the generation of CD8+ T suppressor effector cells. Because NK cell function is decreased in many autoimmune diseases, these cells may fail to interact properly with these individuals' CD8+ cells in generating suppressors of aggressive anti-self responses.

Reduced-intensity conditioning allogeneic hematopoietic cell transplantation for younger patients with acute myeloid leukemia: a registry-based study.

Clinical efficacy of allogeneic hematopoietic cell transplantation (HCT) using reduced-intensity conditioning (RIC) for younger patients remains unclear. We therefore performed a retrospective registry-based study to evaluate outcomes for patients with AML aged between 16 and 49 years who underwent RIC allogeneic HCT. Patients receiving RIC (N=125) showed significantly worse survival than those receiving myeloablative conditioning (MAC; N=1,554) (47.7% for RIC and 54.2% for MAC at 4 years, P=0.047). However, the difference became marginal after adjustment for patient characteristics (P=0.080), and inclusion in the multivariate analysis of the HCT comorbidity index or the propensity score for estimating the likelihood of choosing RIC or MAC further reduced statistical significance (P=0.371 and 0.206, respectively), indicating the existence of a selection bias against RIC. Nevertheless, outcomes for our patients receiving RIC were still acceptable, so that RIC constitutes a potential therapeutic option for younger AML patients who are deemed unsuitable for MAC. Subgroup analyses showed that patients aged between 40 and 49 years as well as those in first or second CR at the time of transplantation exhibited similar outcomes regardless of whether they were treated with RIC or MAC.

Risk factors and prognosis of hepatic acute GvHD after allogeneic hematopoietic cell transplantation.

Hepatic acute GvHD (aGvHD) is associated with high mortality owing to poor response to immunosuppressive therapy. The pathogenesis of hepatic aGvHD differs from that of other lesions, and specific risk factors related to pre-transplant liver conditions should be determined. We conducted a cohort study by using a Japanese transplant registry database (N=8378). Of these subjects, 1.5% had hepatitis C virus Ab (HCV-Ab) and 9.4% had liver dysfunction (elevated transaminase or bilirubin levels) before hematopoietic cell transplantation (HCT). After HCT, the cumulative incidence of hepatic aGvHD was 6.7%. On multivariate analyses, HCV-Ab positivity (hazard ratio (HR), 1.93; P=0.02) and pre-transplant liver dysfunction (HR, 1.85; P<0.01), as well as advanced HCT risk, unrelated donors, HLA mismatch and cyclosporine as GvHD prophylaxis, were significant risk factors for hepatic aGvHD, whereas hepatitis B virus surface Ag was not. Hepatic aGvHD was a significant risk factor for low overall survival and high transplant-related mortality in all aGvHD grades (P<0.01). This study is the first to show the relationship between pre-transplant liver conditions and hepatic aGvHD. A prospective study is awaited to validate the results of this study and establish a new strategy especially for high-risk patients.

Regulation of BCL-6 gene expression in human myeloid/monocytoid leukemic cells.

We demonstrated in the present study that the BCL-6 transcripts were detectable not only in B cells, but also in circulating granulocytes and monocytes from normal individuals, and in human acute nonlymphocytic leukemia cells of certain subtypes (M3, M4, M5). Then, with an assumption that the BCL-6 gene expression may be related to the differentiation of myeloid cells, we analyzed the inducibility of BCL-6 gene expression along monocytic lineage differentiation in HL-60 and U-937 cells by treating them with 12-O-tetradecanoylphorbol-13-acetate (TPA). Although the expression of BCL-6 transcripts was very low or undetectable in untreated HL-60 or U-937 cells, treatment of these cells with TPA to induce monocytic differentiation resulted in an apparent increase of BCL-6 mRNA, suggesting that BCL-6 gene expression is not limited to B cells and it is closely associated with monocytic lineage differentiation. The BCL-6 transcripts in TPA-treated U-937 cells were superinduced by the treatment with cycloheximide (CHX) and the half-life of the BCL-6 mRNA was apparently prolonged when TPA-treated U-937 cells were exposed to CHX in the presence of actinomycin D (ACD). Furthermore, the nuclear run-on assay revealed that the BCL-6 transcription signals were enhanced by TPA treatment. These results suggest that the increase of BCL-6 mRNA in U-937 cells stimulated with TPA to induce monocytic lineage differentiation is mediated by both transcriptional and post-transcriptional regulation.

Cell-permeable ceramide inhibits the growth of B lymphoma Raji cells lacking TNF-alpha-receptors by inducing G0/G1 arrest but not apoptosis: a new model for dissecting cell-cycle arrest and apoptosis.

We examined the effects of a cell-permeable ceramide analog, C2-ceramide, on the growth of TNF-alpha-resistant B lymphoma Raji cells lacking TNF-alpha-receptors (TNF-R). C2-ceramide inhibited the clonal growth of not only TNF-alpha-sensitive myeloid leukemia cells (HL60 and U937) but also Raji cells. Following stimulation with C2-ceramide, HL60 and U937 cells showed apoptotic cell death, whereas Raji cells did not show a detectable level of apoptosis. However, a cell-cycle arrest in G0/G1 phase was observed in Raji cells after the treatment with C2-ceramide, which was accompanied by the dephosphorylation of retinoblastoma (RB) gene products and decreased expression of p53 proteins. Failure of C2-ceramide to induce apoptosis in Raji cells might be explained by the lack or low expression of apoptosis-inducing proteins by two lines of evidence: (1) Raji cells were resistant to apoptosis induced by ceramide even in the presence of transcription/translation inhibitors; (2) Bax protein expression was not detectable in Raji cells, although Bcl-2 protein expression in Raji cells was even less than that in HL60 and U937 cells. Moreover, protein kinase C (PKC), whose activation has been described to inhibit ceramide-induced apoptosis, inhibitor H-7 did not induce apoptotic cell death in Raji cells, suggesting that an imbalance between PKC and ceramide pathways is not the reason for the resistance of Raji cells against ceramide-induced apoptosis. Finally, ceramide-induced activation of nuclear factor kappaB (NF-kappaB) was observed in Raji cells as well as HL60 cells, indicating that activation of this molecule may not be specific for apoptosis. By using the present model, one can dissect cell-cycle arrest and apoptosis induced by ceramide.

The presence and longevity of peripherally expanded donor-derived TCRalphabeta+ mature T lymphocyte clones after allogeneic bone marrow transplantation for adult myeloid leukemias.

There are two major pathways for T-cell regeneration after allogeneic bone marrow transplantation; thymus-dependent T-cell differentiation of T-cell progenitors, and peripheral expansion of mature T cells in the graft. In order to learn to what extent the peripheral expansion of donor-derived mature T lymphocytes contributes to reconstitution of the TCRalphabeta+ T-cell repertoire after allogeneic bone marrow transplantation for adult myeloid leukemias, we pursued the fate of donor-derived T-cell clones using the amino-acid sequences of the complementarity-determining region 3 (CDR3) of the TCR-beta chain as a clonal marker. Clonal expansion of TCRalphabeta+ T lymphocytes with specific TCRBV subfamilies was identified in donor blood. Identical T-cell clones were not found in blood from recipients before transplantation. The donor-derived T-cell clones were identified in the circulating blood from recipients a few months after allogeneic bone marrow transplantation, and they remained in the blood for 18 months after transplant in two recipients, and for 56 months in one. These results suggest that the peripheral expansion of mature T lymphocytes in the graft makes a significant contribution to post-transplant T-cell regeneration during the early period of transplantation in humans, and that mature T cells can survive in recipients for several years. Further investigation will be required to explore which antigens drive the expansion of T-cell clones in donors and recipients, and the mechanisms of maintaining homeostatic balance between the thymus-dependent pathway and the peripheral expansion of mature T cells in post-transplant T-cell regeneration.

Calmodulin activities are significantly increased in both uninvolved and involved epidermis in psoriasis.

In order to elucidate a part of calmodulin actions in the hyperproliferative state in human epidermis, calmodulin activities in the psoriatic and in the normal human epidermis were determined using calmodulin-deficient phosphodiesterase from bovine heart and purified pig skin epidermal calmodulin as a standard. Skin samples were obtained from 11 normal healthy controls and from both the uninvolved and involved regions of 8 nonconsanguineous psoriatic patients. Pure epidermal samples, prepared by the microdissection method, were used for calmodulin assays. Normal human epidermis contained 270 +/- 13 ng/mg dry weight, whereas calmodulin activities were significantly increased in psoriatic epidermis, 412 +/- 29 ng/mg dry weight for the uninvolved epidermis and 747 +/- 46 ng/mg dry weight for the involved epidermis, respectively. These results suggest that calmodulin may play an important role in cell proliferation in human epidermis.

Expression of corticotropin-releasing hormone messenger ribonucleic acid in human pituitary corticotroph adenomas associated with proliferative potential.

Among the factors that promote the growth of human pituitary corticotroph adenomas (hPCAs), the proliferative potential of CRH secreted by hPCAs on these tumors is not well known. In this study, the CRH messenger ribonucleic acid (mRNA) transcripts were demonstrated on paraffin sections using the quantitative in situ hybridization method in 37 of 43 hPCAs, including 17 of 22 microadenomas, 15 of 15 macroadenomas, and 5 of 6 locally invasive adenomas according to Hardy's classification of pituitary adenomas. The more important findings were that CRH mRNA signal intensity in pituitary corticotroph adenoma cells was linearly correlated with Ki-67 tumor growth fractions (r = 0.802; P < 0.0001), and in macroadenoma and locally invasive adenoma cells it was significantly higher than in microadenoma cells (P = 0.035). On the other hand, CRH mRNA transcript accumulation was absent or negligible in 10 normal pituitary glands (P = 0.005). This is the first report of the frequent expression of CRH mRNA localized in human pituitary corticotroph adenoma cells. These results indicate that CRH from a local source of corticotroph adenoma cells not only has autocrine/paracrine functions in corticotroph adenomatous tissue, but also is an important factor associated with a proliferative potential of hPCAs.

Molecular cloning and characterization of a steroid receptor-binding regulator of G-protein signaling protein cDNA.

Steroid hormone receptors are composed of six major functional domains, i.e. the A/B domains as the activation function 1 domain (AF-1), domain C as the DNA-binding domain, domain D as a hinge domain and domain E/F as the ligand-dependent transcriptional domain (AF-2). They regulate gene transcription through interactions with various nuclear factors of their domains, such as AF-1 and AF-2. We have insufficient knowledge of the function of the DNA-binding domain (domain C) except for its DNA-binding function or the hinge domain (domain D). Therefore, we attempted to identify factors interacting with the domains by using a yeast two-hybrid system. Domains C and D of estrogen receptor alpha were used as a bait to isolate cDNA clones from a rat ovary cDNA library. We isolated the cDNA clone of a novel steroid receptor-binding protein bearing the regulator of G-protein signaling (RGS) designated as SRB-RGS. The protein repressed the transcriptional activity of estrogen receptor alpha, suggesting cross-talk of steroid hormones and peptide hormones (or growth factors) for signal transductions mediated by SRB-RGS.

Cell membrane and cytoplasmic staining for MIB-1 in hyalinizing trabecular adenoma of the thyroid gland.

The monoclonal MIB-1 antibody reacts with the nuclei of cells in the late G1, S, G2, and M phases of the cell cycle. Previously, we found two cases of hyalinizing trabecular adenoma that showed cell membrane and cytoplasmic immunopositivity for the antibody. The purpose of this investigation was to confirm this exceptional reactive pattern of MIB-1 in hyalinizing trabecular adenoma. For the study, we collected 13 additional hyalinizing trabecular adenomas and stained a total of 15 tumors using MIB-1 antibody. Ten cases of papillary thyroid carcinoma were studied similarly. All hyalinizing trabecular adenomas showed strong positivity for the antibody in 90% or more of the tumor cells, localized especially to the cell membrane and also to the cytoplasm. There was no cell membrane or cytoplasmic MIB-1 positivity among the 10 papillary carcinomas. Luminal border of normal extratumoral thyroid follicles rarely showed faint immunopositivity. Our findings indicate that strong cell membrane and cytoplasmic immunoreactivity for MIB-1 is a characteristic of the hyalinizing trabecular adenoma. Staining for MIB-1 will be useful in differentiating hyalinizing trabecular adenoma from papillary carcinoma, which shares a number of cytologic and histologic findings with hyalinizing trabecular adenoma.

Hyalinizing trabecular adenoma and papillary carcinoma of the thyroid gland express different cytokeratin patterns.

It has recently been suggested that hyalinizing trabecular adenoma of the thyroid is an encapsulated variant of papillary carcinoma because of certain similarities of their histology, the occasional occurrence of both tumors in the same gland, and their similar pattern of expression of cytokeratins, including staining for cytokeratin 19. To investigate this notion further, we examined immunocytochemically the expression of a series of cytokeratins in 12 hyalinizing trabecular adenomas and six papillary carcinomas. Hyalinizing trabecular adenoma showed no or minimal reactivity for cytokeratin 19, whereas papillary carcinoma was almost always strongly reactive. Also, hyalinizing trabecular adenoma showed no staining for high-molecular-weight (HMW) cytokeratin, whereas papillary carcinoma was strongly positive. Thus, there are different patterns of cytokeratin 19 and HMW cytokeratin expression in hyalinizing trabecular adenoma and papillary carcinoma. The findings do not support the suggestion that hyalinizing trabecular adenoma is an encapsulated variant of papillary carcinoma.

Intramyocardial angiomyolipoma.

We report a case of cardiac angiomyolipoma in a 48-year-old woman who went to the hospital because of shortness of breath. Cardiac ultrasonography showed a right atrial mass, which was surgically removed. Pathologic examination revealed a 6-cm-diameter, dome-shaped mass composed of a mixture of blood vessels, smooth muscle, and fat. Because of its distinctive morphology and location, we diagnosed it as an intramyocardial angiomyolipoma. There was no evidence of tuberous sclerosis. Since excision of the mass, the patient has remained well without recurrence for 20 months. Angiomyolipomas usually develop in the kidney; extrarenal occurrence is rare. To date, no case of a cardiac angiomyolipoma has been reported in the English literature. The histogenesis of angiomyolipoma is uncertain, but it is most likely hamartomatous in nature.

Transmembrane signaling through CD80 (B7-1) induces growth arrest and cell spreading of human B lymphocytes accompanied by protein tyrosine phosphorylation.

We addressed the issue of the role for CD80 (B7-1) expressed on human B cells in transmembrane signaling. Cross-linking of CD80 on B lymphoma Raji cells induced tyrosine phosphorylation in 160-, 120-, 55-, 46- and 44-kDa proteins, which was inhibited by genistein. CD80-mediated signaling resulted in the inhibition of DNA replication of B cells and induced the changes in morphology like macrophages or fibroblasts. This cell spreading was inhibited by the pre-treatment of the cells with genistein. These results suggest that the CD80 antigen is involved in transmembrane outside-in signaling in B cells and its biological effects appear to be mediated by tyrosine kinases.

Mechanisms of allogeneic stimulation induced tumor necrosis factor-alpha (TNF-alpha) production.

We investigated the mechanisms of allogeneic stimulation induced TNF-alpha production in vitro by using human peripheral blood mononuclear cells (PBMC) and Daudi lymphoblastoid B-cells. PBMC produced TNF-alpha in response to mitomycin C-treated or paraformaldehyde-fixed Daudi cells, reaching a peak level after 4-6 h of culture. Monocytes were identified as the major source of TNF-alpha produced during allogeneic cell interaction. The second potent producer of TNF-alpha was E-rosette non-forming natural killer cells. Purified T-cells did not produce significant levels of TNF-alpha, even in the presence of IL-1 and IL-6. Interleukin-4 (IL-4) down-regulated TNF-alpha production by monocytes, but in contrast interferon-gamma (IFN-gamma) moderately enhanced TNF-alpha production. Our results indicate that monocytes are mainly responsible for the production of TNF-alpha in response to allogeneic stimulation, and T-cells modulate monocyte function by their soluble factors.

Evidence for the in vivo production of interleukin-3 in lethally irradiated mice transplanted with syngeneic murine splenocytes.

We wish to demonstrate new evidence for the in vivo production of interleukin-3 (IL-3). Syngeneic murine splenocytes were transplanted into lethally irradiated mice. The spleen cells in these transplant mice spontaneously produced IL-3 in cultures, and IL-3-like activity was detected in the serum. Chronological changes of the Thy-1 antigen expression on the bone marrow cells, and the number of myeloid progenitors in the bone marrow from post-transplant mice correlated with the amount of IL-3 produced in vivo. These results suggest that IL-3 may be produced by activated T cells during the syngeneic mixed lymphocyte reaction induced in vivo.