Asymptotically Safe Standard Model via Vectorlike Fermions.

We construct asymptotically safe extensions of the standard model by adding gauged vectorlike fermions. Using large number-of-flavor techniques we argue that all gauge couplings, including the hypercharge and, under certain conditions, the Higgs coupling, can achieve an interacting ultraviolet fixed point.

Viable dark matter via radiative symmetry breaking in a scalar singlet Higgs portal extension of the standard model.

We consider the generation of dark matter mass via radiative electroweak symmetry breaking in an extension of the conformal standard model containing a singlet scalar field with a Higgs portal interaction. Generating the mass from a sequential process of radiative electroweak symmetry breaking followed by a conventional Higgs mechanism can account for less than 35% of the cosmological dark matter abundance for dark matter mass M(s)>80 GeV. However, in a dynamical approach where both Higgs and scalar singlet masses are generated via radiative electroweak symmetry breaking, we obtain much higher levels of dark matter abundance. At one-loop level we find abundances of 10%-100% with 106 GeV80 GeV detection region of the next generation XENON experiment.

Intravascular lymphomatosis: a clinicopathologic study of 10 cases and assessment of response to chemotherapy.

PURPOSE: We report a clinicopathologic study of 10 cases of intravascular lymphomatosis (IVL) seen at a single institution, and assess the response to chemotherapy in these patients, as well as those collected from a literature review. PATIENTS AND METHODS: The clinical, pathologic, and immunophenotypic features of 10 cases of IVL diagnosed at the Johns Hopkins Hospital since 1977 were studied. Follow-up information was obtained in each case by consultation with the treating physician. In addition, cases of IVL reported previously in which patients were treated with chemotherapy and for which follow-up data were available at the time of publication were reviewed. RESULTS: In the present series of 10 cases, the most common clinical features were fever of unknown origin (FUO), mental status changes, and rash. Diagnostic specimens were obtained from a variety of sources, including brain, skin, prostate, liver, kidney, and gallbladder. All of the four patients treated with combination chemotherapy are alive and two have achieved long-term survival (48 and 45 months, respectively); the remaining two are alive and in complete remission (CR) after short follow-up duration of 6 months. Among 35 patients reported in the literature who received chemotherapy (including four from this series), 43% attained a CR and were free of disease at the time of publication. None of the three patients in our series who received localized therapy (surgery with or without radiation therapy) is alive (mean survival duration, 9 months). For the three patients diagnosed at postmortem examination, the mean interval between onset of symptoms and death was 3 months, and disease was widespread. CONCLUSION: These findings suggest that IVL represents a high-grade non-Hodgkin's lymphoma (NHL) with a propensity for systemic dissemination, and that CR and long-term survival may result in patients treated with aggressive combination chemotherapy.

Phase II trial of pentostatin in refractory lymphomas and cutaneous T-cell disease.

Thirty-seven patients with refractory lymphoma or cutaneous T-cell lymphoma were treated with 2'-deoxycoformycin (pentostatin; dCF), 5 mg/m2 intravenous (IV) bolus for 3 consecutive days of every 3-week cycle in this Eastern Cooperative Oncology Group (ECOG) trial. Included were 25 with the diagnosis of non-Hodgkin's lymphoma, three with Hodgkin's disease, eight with cutaneous T-cell lymphoma (CTCL), and one with unknown subtype, of whom 31 were considered eligible. The majority had failed at least two, but no more, conventional chemotherapy regimens. Ten (32%) of the eligible patients had a partial response (PR), including patients with nodular poorly differentiated lymphocytic (NPDL), nodular mixed (NM), diffuse poorly differentiated lymphocytic (DPDL), or diffuse histiocytic (DH), lymphoma mixed-cellularity (MC), Hodgkin's disease, and unknown subtype, and in four patients with CTCL. The overall median time to treatment failure (TTF) was only 1.3 months, but the range extended to 57.3 months. The overall response duration was 16.0 months, and the range extended to 53.4 months. Overall median survival was 2.7 months, with the range extending to 63.2 months. The majority of patients had no toxicity, but there were some instances of severe or life-threatening events. Four fatal toxicities occurred, in two patients with underlying pulmonary conditions and two with prior cardiac histories. From this study, we conclude that dCF is active in refractory lymphomas and CTCLs, should be avoided in patients with a history of serious pulmonary or cardiac diseases, and warrants consideration for incorporation of a low-dosage schedule into conventional combination chemotherapy regimens, including its use with biologic response modifiers.

Activity of fludarabine in previously treated non-Hodgkin's low-grade lymphoma: results of an Eastern Cooperative Oncology Group study.

PURPOSE: Fludarabine (2-fluoro-arabanoside-monophosphate) is a new antimetabolite chemotherapeutic agent. We performed a multicenter, phase II study of this drug in previously treated patients with refractory or relapsed non-Hodgkin's lymphoma (NHL) to determine its response rate by histologic classification. PATIENTS AND METHODS: Sixty-two assessable patients were given 18 mg/m2 by intravenous (IV) bolus injection daily for 5 days, every 28 days. Forty-eight percent had previously had one chemotherapy regimen, and the remainder had had two regimens; 42% had had radiation. RESULTS: Patients received 273 cycles of fludarabine chemotherapy, with a median of two cycles and ranging up to 25 cycles. Sixty patients were assessable for response, including nine complete responses (CRs; 15%) and nine partial responses (PRs; 15%). The response rate for patients with lower-grade histology was 52% (13 of 25); the greatest response rate was seen in those with follicular small cleaved-cell lymphoma, including seven of 11 treated. Five responders remain in unmaintained remission; the median survival of responders is greater than 30 months. Toxicity included mild neutropenia and a 10% incidence of grade 3 neurologic toxicity with occasional reversible visual and auditory changes. CONCLUSION: Fludarabine is active in patients with previously treated NHL (particularly low-grade histologies). Future studies will examine its activity in combination with other chemotherapeutic agents in previously untreated patients.

Prospectively randomized clinical trial of three intensive chemotherapy regimens for the treatment of advanced unfavorable histology non-Hodgkin's lymphoma.

Three hundred thirty-two eligible patients with advanced (Ann Arbor stage III or IV) non-Hodgkin's lymphoma of aggressive histologic subtype (Rappaport classification diffuse histiocytic [DH], diffuse poorly differentiated lymphocytic [DPDL], diffuse mixed [DM], or diffuse undifferentiated [DU]) were randomly assigned to receive induction chemotherapy with one of three intensive regimens in a clinical trial conducted by the Eastern Cooperative Oncology Group (ECOG) between 1978 and 1983. Chemotherapy regimens consisted of cyclophosphamide, vincristine, prednisone, and doxorubicin (Adriamycin; Adria Laboratories, Columbus, OH) (COPA) administered in 3-week cycles; cyclophosphamide plus doxorubicin plus prednisone beginning day 1, with vincristine plus bleomycin day 15 of each 3-week cycle (COPA + Bleo); or cyclophosphamide plus doxorubicin plus procarbazine beginning day 1, and bleomycin plus vincristine plus prednisone beginning day 15 of each 4-week cycle (CAP-BOP). The median patient follow-up from study entry for patients still alive is 5 years. The three regimens were not significantly different with respect to complete response (CR) rates (43% to 46%), time to progression of malignant disease (median, 1.0 to 1.7 years), or survival (5-year survival, 34% to 45%), although duration of complete remission appeared to be shorter in patients receiving COPA (P = .03). COPA + Bleo and CAP-BOP were significantly more toxic than the COPA regimen. This study did not demonstrate any substantial therapeutic advantage associated with the addition of a fifth or sixth chemotherapy drug, or with treatment administered on a more frequent administration schedule, compared with the COPA regimen in this population of patients with advanced diffuse non-Hodgkin's lymphoma. The relatively small proportion of long-term disease-free survivors treated with COPA underscores the need for prospective clinical trials of new and more effective treatments for patients with these potentially curable tumors.

High-dose cytotoxic therapy and bone marrow transplantation for relapsed Hodgkin's disease.

Patients with Hodgkin's disease who have failed two or more chemotherapy regimens or who have relapsed after an initial chemotherapy-induced remission of less than 12 months are seldom cured with conventional salvage therapies. We studied the effect of high-dose cytoreductive therapy followed by bone marrow transplantation in 50 such patients with relapsed Hodgkin's disease. Twenty-one patients with histocompatibility locus antigen (HLA)-matched donors had allogeneic marrow transplants, one patient received marrow from an identical twin, and 28 patients without a matched donor received autologous grafts purged with 4-hydroperoxycyclophosphamide. Busulfan plus cyclophosphamide was the preparative regimen for the 25 patients who had received extensive prior irradiation, and the other 25 patients received cyclophosphamide plus total body irradiation. The overall actuarial probability of event-free survival at 3 years was 30%, with a median follow-up of 26 months. The event-free survival following transplantation was influenced by the number of chemotherapy failures and the patient's response to conventional salvage therapy prior to transplant. The 16 patients who were transplanted at first relapse, while still responsive to standard therapy, had a 64% actuarial probability of event-free survival at 3 years. Age, presence of extranodal disease, preparative regimen, and type of graft (autologous v allogeneic) were not significant prognostic factors. The majority of transplant-related deaths were from interstitial pneumonitis; inadequate pulmonary function, multiple prior chemotherapy regimens, and prior chest irradiation all appeared to increase the transplant-related mortality. These results suggest a role for marrow transplantation in a subset of patients with relapsed Hodgkin's disease who are unlikely to be otherwise cured but are still responsive to conventional-dose cytoreductive therapy.

Morphological subclassification of follicular lymphoma: variability of diagnoses among hematopathologists, a collaborative study between the Repository Center and Pathology Panel for Lymphoma Clinical Studies.

A collaborative study between the Repository Center for Lymphoma Clinical Studies and the members of the lymphoma pathology subcommittee of the major cooperative oncology groups was undertaken in an effort to ascertain the reproducibility and the interobserver agreement for the cytologic diagnosis of follicular lymphomas. A group of 105 patients with follicular lymphomas were subclassified by seven hematopathologists according to two methods. In the first method, cases were subclassified according to the Rappaport, Lukes, and Collins, and Working Formulation systems. In these systems, follicular lymphomas are subclassified by estimation of the different cell populations without the actual counting of cells. With this method, great variability in diagnosis was noted. For example: (1) The consensus diagnosis was that of poorly differentiated lymphocytic lymphoma (PDL) in 39 cases, but among the individual pathologists the number of cases thus diagnosed ranged from 24 to 65; (2) In 40 cases, the consensus diagnosis was follicular lymphoma, mixed-cell type; however, all seven pathologists independently agreed on this subtype in only one case; (3) A major disagreement was noted in 39 cases (37%), in which both diagnostic extremes (small cleaved and large noncleaved) were expressed. In the second method, only precise counts of different cells were made, according to a modification of the method recommended by Berard. With this counting method, diagnoses were independently derived based on the counts provided by the seven pathologists for large cleaved, small noncleaved, and large noncleaved cells. The variability in the results was wide also with this second method. For example, the average number of large cells found by each pathologist was ascertained, and the ranges were determined. The average range was 28 cells, which was considered high. The same determinations were performed only for large noncleaved cells, and the range was found to be 15 cells, which was also considered high. When the diagnoses derived from counts of only large noncleaved cells were compared with the traditional, more subjective diagnoses, fairly close agreement was obtained. In summary, the great variability in diagnoses of follicular lymphomas among pathologists may be attributed to the difficulties inherent in accurate determination of cell size and of the precise percentages of different cells. Until solutions to these problems are developed, one can subclassify follicular lymphomas according to the Berard method or the estimation method.

Long-term results of blood and marrow transplantation for Hodgkin's lymphoma.

PURPOSE: To evaluate the long-term outcome after allogeneic (allo) and autologous (auto) blood or marrow transplantation (BMT) in patients with relapsed or refractory Hodgkin's lymphoma (HL). PATIENTS AND METHODS: We analyzed the outcome of 157 consecutive patients with relapsed or refractory HL, who underwent BMT between March 1985 and April 1998. Patients

Non-Hodgkin's lymphomas in leukemic phase: clinicopathologic correlations.

A leukemic phase occurred in 30 (14 percent) of 214 patients with non-Hodgkin's lymphoma. To determine the significance of peripheral blood involvement in each type of NHL, patients were subdivided according to a modified Rappaport classification. Each histologic subtype presented a homogeneous clinical picture which differed from that seen in other histologic subtypes. Of particular note was the recognition of two distinctive cytologic and clinical subtypes within the category of nodular lymphoma, poorly differentiated lymphocytic lymphoma (NPDL). In one subtype, the predominant cells had cytologic features akin to those of lymphoblasts. In these cases, although the interval to peripheral blood involvement was variable, the median leukemic survival was only two months. In contrast in conventional NPDL the median leukemic survival was 43+ months, and peripheral blood involvement did not appear to exert an independent effect on prognosis. In diffuse large cell lymphomas the median leukemic survival was 0.5 months, with peripheral blood involvement appearing as a terminal event associated with unresponsive disease in multiple sites. The recognition of adult lymphoblastic lymphoma as a clinicopathologic entity with a high risk of leukemic conversion, 100 percent in this study, is also confirmed.

Immunologic and morphologic studies of T cell lymphoma.

Thymic-independent (B) lymphocytes, thymic-independent (T) lymphocytes and histiocytes may be distinguished by the presence of certain surface markers. In addition B and T lymphocytes have been reported to show distinctive surface architecture by scanning electron microscopy. Neoplastic cells from a lymph node and cerebrospinal fluid of a patient with a diffuse malignant lymphoma of the poorly differentiated lymphocytic type were examined in frozen sections and cell suspensions for the presence of surface immunoglobulin and the antigen-antibody-complement (IgMEAC) receptor of B lymphocytes, the presence of the cytophilic antibody (IgGEA) receptor of histiocytes and the ability to form nonimmune rosettes with sheep red blood cells (E) characteristic of T lymphocytes. Cells from the lymph node were also studied by scanning electron microscopy. The majority of neoplastic cells from the lymph node and cerebrospinal fluid formed rosettes with E, but lacked surface immunoglobulin and failed to bind IgMEAC or IgGEA. By scanning electron microscopy the neoplastic cells, although larger in diameter, showed surface architecture similar to normal lymphocytes with a varying number of surface microvilli. These studies suggest that the malignant cells of this lymphoma are of thymic type.

Unusual manifestation of tuberculosis: TE fistula.

Fistulas between the tracheobronchial tree and the esophagus (TE fistula) caused by tuberculosis are rare; usually they are associated with readily apparent pulmonary and/or mediastinal infection, and require surgical management. The patient we describe presented with a TE fistula as the only manifestation of active tuberculosis. This case represents the first report of successful nonsurgical treatment of tuberculous TE fistulas.

Blastic natural killer cell leukemia/lymphoma: a clinicopathologic study.

The classification of natural killer (NK)-cell and NK-like T-cell malignancies has undergone significant evolution in recent years. Although examples of NK-cell tumors resembling acute leukemia have been described anecdotally as blastic, blastoid, or monomorphic NK-cell leukemia/lymphoma (NKL/L), the clinical and pathologic features of these tumors have not been systematically defined. We report four patients with blastic NKL/L and describe the clinical, pathologic, and immunophenotypic findings in these cases. All patients were elderly (58-82 years) and presented with cutaneous plaques. Two patients also had adenopathy, and three patients had marrow involvement at presentation. Biopsy of cutaneous lesions showed atypical superficial and deep dermal lymphoid infiltrates. Involved lymph nodes were architecturally effaced by an interfollicular infiltrate with blastic cytologic features. In Wright-Giemsa-stained blood or marrow smears, tumor cells had finely distributed nuclear chromatin, many with nucleoli, and variable amounts of cytoplasm. In contrast to many NK and NK-like T-cell disorders, azurophilic cytoplasmic granules were absent or inconspicuous. The tumor cells were immunophenotypically distinctive. They expressed intermediate density CD45, as is characteristic of blasts; in addition, the cells were positive for HLA-DR, CD2, CD4, and the NK-associated antigen CD56. Surface CD3, cytoplasmic CD3, and CD5 were negative in all cases tested, whereas CD7 was expressed in two cases. In formalin-fixed tissue, tumor cells marked with antibodies to CD43, but not with other T- or B-lineage-related antibodies. All three cases studied for Epstein-Barr viral RNA by in situ hybridization were negative. Although treatments varied, all three patients with clinical follow-up died within months of the diagnosis. The clinical course in two patients culminated in an overtly leukemic phase. These findings suggest that blastic NKL/L represents a distinct clinicopathologic entity, characterized by cutaneous, nodal, and marrow involvement by blastic cells with immunophenotypic characteristics of true NK cells. The disease afflicts elderly patients, pursues an aggressive course, and may culminate in overt leukemia.

Epstein-Barr virus is infrequently identified in non-Hodgkin's lymphomas associated with Hodgkin's disease.

Epstein-Barr virus (EBV) was identified in a subset of cases of Hodgkin's disease (HD) and in some non-Hodgkin's lymphomas (NHLs), particularly those associated with immunodeficiency. Because patients with HD have associated immune system defects, we hypothesized that EBV might be involved in NHLs associated with HD. Using fixed paraffin sections and in situ hybridization for EBV EBER1 RNA, we studied 12 cases of composite NHL + HD, two patients with NHL who simultaneously also had HD involving a different site (simultaneous HD and NHL), 14 NHLs arising in patients who previously had HD, and seven NHLs from patients who subsequently developed HD. Epstein-Barr virus was identified most frequently in composite NHL + HD. Five (42%) cases of composite NHL + HD contained EBV in Reed-Sternberg and Hodgkin cells, four of which also had EBV-positive NHLs, diffuse mixed or large-cell type, with 10 to more than 50 EBV-positive cells per x400 microscopic field. These results suggest that in this subset of four cases, both the NHL and HD components may have arisen from the same EBV-infected progenitor cell. We did not find EBV in two cases of simultaneous NHL and HD or in seven NHLs preceding development of HD. We identified EBV in only two of 14 NHLs following HD, one small noncleaved cell lymphoma and one plasmacytoma, both containing more than 50 EBV-positive cells per x400 microscopic field. These results suggest that EBV plays a minimal role in NHLs associated with HD, with the exception of composite NHL + HD. Hodgkin's disease-associated immune defects may be involved in the pathogenesis of a subset of NHLs following HD, but the exact pathogenesis of most NHLs associated with HD remains uncertain. Parallels with the high-grade Burkitt-like lymphomas associated with human immunodeficiency virus infection are noted.

Changes in quantitative SPECT thallium-201 results associated with the use of energy-weighted acquisition.

The effect of utilizing energy-weighted acquisition on quantitative analysis of SPECT thallium-201 images was evaluated by simultaneously acquiring energy-weighted and windowed projection images in ten patients. The paired image sets were processed identically and evaluated by probability analysis of defect magnitude as indicated by a commercially available software analysis package. It was predicted that defect magnitude would increase as a result of improved image contrast. This was confirmed experimentally. One should be cautious in relying on strict quantitative criteria in cardiac studies with thallium-201, especially when major changes in the imaging system or technique are introduced.

Epstein-Barr-encoded RNA in situ hybridization: diagnostic applications.

Latent Epstein-Barr virus (EBV) infection is associated with a variety of malignancies and other diseases. Highly restricted viral antigen expression and low viral genome copy number in infected tissues impede conventional immunohistochemical or in situ hybridization approaches to the detection of virus in these tissues. In situ hybridization detection of two small but very abundant nuclear RNAs known as the EBERs serves as an alternative approach. The EBERs are stable over time and can be detected in all common fixatives. This technique facilitates characterization of the cellular locus of latent EBV infection in histologically complex tissues, such as Hodgkin's disease and angioimmunoblastic lymphadenopathy with dysproteinemia.

Mitotic counts in follicular lymphomas.

Increased mitotic activity is associated with significantly shorter patient survival in some of the subtypes of diffuse non-Hodgkin's lymphomas. This study on 105 cases of follicular lymphoma was undertaken to determine the clinical significance of mitotic activity in follicular lymphomas. For each case, two pathologists independently counted mitotic figures in 20 random high-power fields. The difference of the average mitotic counts over 20 high-power fields for the two pathologists showed a Gaussian distribution with a median difference of -0.26 counts per high-power field and a standard error of 0.10 per cent. In 94 cases (91 per cent), the difference was less than two mitotic counts per high-power field, indicating good interobserver agreement. There was a statistically significant difference in mitotic counts between subtypes of follicular lymphoma as well as a gradient among subtypes, with the lowest mitotic activity in the poorly differentiated lymphocytic subtype and highest in the undifferentiated subtype. A multivariate statistical analysis of clinical and pathologic variables showed that mitotic figures were not of prognostic significance.

Interaction of rifampin and warfarin.

A 72-year-old man who had been taking rifampin daily for several months was concurrently administered warfarin daily for ten weeks. During this period, the prothrombin time (PT) rose remarkably little as the dosage of warfarin was increased. With difficulty, satisfactory anticoagulation was achieved by giving warfarin 20 mg daily. On discontinuation of rifampin therapy, the PT increased significantly, and subsequent stabilization of the PT within therapeutic range required treatment with warfarin 7.5 mg daily.

Treatment of poor prognosis non-Hodgkin's lymphoma using cyclophosphamide and total body irradiation regimens with autologous bone marrow rescue.

Twenty patients with poor prognosis non-Hodgkin's lymphoma received regimens which employed cyclophosphamide and total body irradiation followed by autologous bone marrow rescue. There were two toxic deaths. All 10 patients with residual disease prior to treatment achieved a complete remission. Ten patients survive disease free from 1.4 to 9.5 years and median survival exceeds 2.9 years. The actuarial 3-year disease-free survival is 50%. Treatment with cyclophosphamide and total body irradiation followed by autologous bone marrow infusion is an effective salvage regimen for poor prognosis lymphoma. Durable long-term remissions can be achieved.

Are there site-specific differences among extranodal aggressive B-cell neoplasms?

Aggressive B-cell lymphomas, including diffuse large cell, Burkitt, and lymphoblastic types, may affect a wide variety of extranodal sites. Up to 40% of these tumors are initially diagnosed in extranodal locations. Regardless of site, these tumors have many histologic similarities; however, some clinical, cytologic, immunologic, and etiologic features of these tumors seem to be distinctive for particular sites of extranodal presentation. In accordance primarily with the extranodal locations presented at the Society for Hematopathology Fourth Slide Workshop on Extranodal Hematopoietic/Lymphoid Disorders (Excluding Bone Marrow and Spleen), the distinctive features of the aggressive B-cell lymphomas of the mediastinum, breast, bone, skin, and body cavities as well as the rare, but primarily extranodal intravascular lymphomatosis, will be discussed.