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Biomedical subjects

D C Fisher

Publications and source records attributed to D C Fisher.

At least 37 records · Page 2Linked to original sources

Cyclophosphamide, doxorubicin, vincristine, prednisone dose intensification with granulocyte colony-stimulating factor markedly depletes stem cell reserve for autologous bone marrow transplantation.

Hematopoietic growth factors allow dose escalation of chemotherapy. This approach may potentially reduce the quality and quantity of hematopoietic stem cells. The capacity of stem cells recovered after dose intensification to support myeloablative therapy is unknown. In patients with previously untreated advanced follicular lymphoma, trilineage hematopoietic engraftment was compared in two sequential trials of induction therapy (standard dose cyclophosphamide, doxorubicin, vincristine, prednisone [CHOP] without growth factors or dose intensification CHOP supported by granulocyte colony-stimulating factor [G-CSF ]) followed by identical myeloablative therapy and autologous stem cell support. Neutrophil, platelet, and red blood cell (RBC) engraftment were compared on days 100, 180, and 360 after stem cell reinfusion. Despite similar patient characteristics including reinfusion of comparable numbers of marrow mononuclear cells, after stem cell transplantation, a highly significant prolongation of neutrophil and platelet engraftment was seen in patients who received high dose CHOP and G-CSF in comparison to standard dose CHOP. These findings suggest that dose intensified chemotherapy and G-CSF recruited stem cells into a proliferative phase and that G-CSF allowed retreatment at a time when stem cells were susceptible to damage by cytotoxic therapy. Such inadequate hematologic engraftment after myeloablative therapy might be avoided by either shortening the time that growth factor support is administered, lengthening the interval between cycles, or attempting to repetitively harvest additional stem cells either from the marrow or peripheral blood. Therefore, intensification of chemotherapy with growth factor support must be used with caution if stem cells are to be used to support myeloablative therapy.

Adult↗

Thrombotic microangiopathy as a complication of high-dose chemotherapy for breast cancer.

Five hundred and eighty-one patients with stage II-IV breast cancer were treated at Duke University Medical Center with high-dose chemotherapy, followed by hematopoietic support. All patients received a conditioning regimen of cyclophosphamide, cisplatin and carmustine. Of these patients, 15 (2.6%) developed symptoms similar to the hemolytic-uremic syndrome with evidence of thrombotic microangiopathy (TMA). The time of onset ranged from 75 days to 281 days post-transplant, with a median of 143 days. Hemolytic anemia and thrombocytopenia, without alternative cause, were required for diagnosis. All patients were treated with steroid therapy. In addition, 12 patients were treated primarily with plasmapheresis, and received a median of 46 treatments. Additional therapy included staphylococcal protein A column apheresis (eight patients), vincristine (three patients) and danazol (one patient). The mortality rate was 11 of 15 patients (73%). These patients had a median survival of 41 days from diagnosis of TMA (range 2-76 days). The four survivors are alive at 76, 186, 1837 and 2387 days from diagnosis of TMA. Three of these patients received twice daily plasmapheresis and protein A column apheresis therapy. One patient recovered without specific therapy. TMA is an infrequent complication of high-dose chemotherapy, but is associated with a high mortality. It frequently follows significant pulmonary drug toxicity. Survival may be improved with early diagnosis and aggressive plasmapheresis therapy.

Anemia, Hemolytic↗

Central nervous system lymphoma not detectable on single-photon emission CT with thallium 201.

A 33-year-old man with acquired immunodeficiency syndrome had an erosive supraglottic mass visible on CT scans of the neck; biopsy was postponed because of the patient's debilitated condition. Two weeks later, he was admitted with altered mental status; an MR image of the brain obtained at that time showed multiple bilateral mass lesions, the largest of which was 5 cm. Findings on a thallium-201 single-photon emission CT (SPECT) scan of the brain were normal. Ten days later, the patient died and autopsy showed both the neck and the brain lesions to be large-cell lymphoma. This case is counterevidence to the reported 100% sensitivity of thallium-201 brain SPECT for demonstrating lymphoma of the central nervous system.

Adult↗

The incidence of patent foramen ovale in 1,000 consecutive patients. A contrast transesophageal echocardiography study.

STUDY OBJECTIVE: Patent foramen ovale (PFO) is present in 10 to 35% of people and has been reported to be an important risk factor for cardioembolic cerebrovascular accidents (CVAs) and transient ischemic attacks (TIAs), especially in younger patients. While contrast transthoracic echocardiography has been used to detect PFO, contrast transesophageal echocardiography (TEE) has a greater sensitivity. Prior studies reported the incidence of PFO in patients presenting with a CVA or TIA. DESIGN: To determine the incidence of PFO in a more general population, we reviewed 1,000 consecutive TEEs performed with contrast and color Doppler for the presence of PFO and other cardioembolic risk factors, including atrial septal aneurysm (ASA), aortic plaque, atrial fibrillation (AFib), and atrial thrombi. While imaging with monoplane or biplane TEE, multiple injections of agitated saline solution were injected during cough or Valsalva maneuver to detect flow through a PFO. PATIENTS: There were 482 male and 518 female patients with mean age of 60 +/- 17 years (range 11 to 93 years). RESULTS: Patent foramen ovale was found in 9.2% of all patients and, though seen in all age groups divided by decade, the incidence in patients aged 40 to 49 years was greater than those aged 70 to 79 years (12.96% vs 6.15%, p = 0.03). Contrast TEE had a much higher detection rate than color Doppler alone. Importantly, there was no greater incidence of PFO in patients with CVA vs those without CVA, or in male vs female patients. Also, there was a very strong correlation between the presence of ASA and PFO (p < .001). CONCLUSION: Thus, PFO detected by TEE, frequently seen with ASA, is seen in all age groups and does not in itself present a risk factor for CVA. The association of PFO with peripheral thrombosis and CVA needs further study.

Adolescent↗

How well do family physicians manage sexually transmitted diseases?

OBJECTIVE: To identify gaps in knowledge about sexually transmitted diseases (STDs) and evaluate practice. DESIGN: We compared how 49 family physicians managed 249 episodes of STDs with the recommendations of the 1988-1989 Canadian STD management guidelines. (The study took place before revised guidelines were distributed in late 1992.) SETTING: Family physicians' practices throughout Canada. PARTICIPANTS: Physicians recruited by the National Research System from among the members of the College of Family Physicians of Canada. These physicians had been in practice for a mean of 9 years; 43 were Certificants of the College. MAIN OUTCOME MEASURES: Family physicians' self-reported episodes of sexually transmitted disease evaluated in light of current Canadian guidelines. RESULTS: Of the 249 episodes studied, 215 (86.3%) were treated effectively, and 34 (13.7%) were judged to have been treated ineffectively. Of the 215 effective treatments, 67 (31.2%) were not completely in agreement with current guidelines. CONCLUSION: Experienced family physicians with postgraduate training usually manage STDs well. The number of ineffective treatments and effective treatments not following the 1988-1989 guidelines, especially for pelvic inflammatory disease, indicates that information on managing certain STDs and syndromes should be made available to all family physicians in a format that is easy to read and use.

Adolescent↗

Advances in the clinical use of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor to intensify cancer chemotherapy.

The majority of human malignancies remain refractory to current therapeutic regimens. Several animal and human models provide evidence of a dose-response effect of many chemotherapeutic agents in a variety of malignancies. In recent years dose escalation with bone marrow transplant support has provided encouraging evidence that increased doses of antineoplastic agents may overcome clinical drug resistance. However, this approach has been limited by hematologic toxicity. This problem has been abrogated by the development and use of hematopoietic growth factors. These agents now offer the oncologist new treatment opportunities.

Chemotherapy, Adjuvant↗

Preexposure of resting B cells to interferon-gamma enhances their proliferative response to subsequent activation signals.

In this report we demonstrate that pretreatment of resting splenic B cells with IFN-gamma increases their mitogenic response to subsequent activating stimuli. This effect is completely blocked by neutralizing anti-IFN-gamma antibodies. By contrast, a similar effect induced by partially purified BCGF is not completely inhibited by anti-IFN-gamma antibody, inferring that as in the mouse, a B-cell-specific factor may also induce increased responsiveness to mitogens in resting B cells. The mechanism of this response was analyzed. Phenotypic and cell cycle analyses of the IFN-gamma-treated cells following activation were not significantly different from control cells with respect to kinetics, although as expected from thymidine uptake, more cells were actively cycling. Even when a very early manifestation of cell activation, Ca2+ flux was examined, no response to IFN-gamma alone was evoked, and the response to subsequent activation was identical to that of control cells. These data show that IFN-gamma did not directly activate B cells, but primed B cells in a manner which amplified subsequent mitogenesis.

Antibodies, Anti-Idiotypic↗

Studies of the in vitro activation and differentiation of human B lymphocytes. II. Optimization of activation by anti-immunoglobulin antibody bound to beads: analysis of the role of autocrine effects on B-cell proliferation and of T-cell help in B-cell differentiation.

We report experiments attempting to optimize the proliferative response of human B cells to rabbit anti-immunoglobulin antibody (RAHIg)-linked beads (anti-Ig beads). By choosing polyacrylamide beads of small size (3 micron) and coupling anti-Ig to them at high concentrations, beads were obtained which were both B-cell specific and more highly mitogenic than other than anti-Ig reagents and B-cell mitogens (SAC, protein A). Using these beads to activate B cells, the augmentation of the anti-Ig-induced proliferative response by added T-cell-derived growth factors was largely eliminated at high cell densities although the effect of these factors was still evident at low cell densities. However, when cultures were performed in round-bottom vessels which crowded the B cells together, the response to anti-Ig beads was independent of T-cell factors even at low B-cell densities, suggesting that normal B cells triggered by anti-Ig beads are able to maintain their own proliferation. In contrast to the proliferative response, even with the most potent anti-Ig bead preparations, no differentiation (Ig production or expression of terminal differentiation markers) was evident unless T-cell help was provided.

Antibodies, Anti-Idiotypic↗

Social reinforcement: a treatment component in verbal self-instructional training.

This study investigated the effects of noncontingent social reinforcement on social and academic behaviors in grade school children. Twenty-four children in the second through fifth grades were selected on the basis of teacher ratings of disruptive behavior. Subjects were divided into a high social reinforcement verbal self-instructional (VSI) training group, a low social reinforcement VSI group, and a no-contact control group. Children in VSI groups were removed from their classrooms during four 40-minute periods and given VSI training. Significant between-groups differences on measures of social reinforcement were found indicating its successful manipulation. While none of the dependent measures indicated significant differences between experimental groups, a consistent pattern of difference scores emerged giving limited support to the hypothesis that noncontingent social reinforcement contributed to behavioral gains. Results are discussed in terms of the need for future research on the effects of rapport on treatment outcome.

Behavior Therapy↗

Doppler ultrasound in noninvasive cardiac evaluation. The growing range of applications.

Ultrasound is of proven clinical utility for imaging cardiac structures. Doppler ultrasonic techniques can be used with or without echocardiography for noninvasive hemodynamic studies. The usefulness of Doppler ultrasonic techniques in the noninvasive laboratory has been shown recently at the Massachusetts General Hospital, Boston. In 61 of 100 consecutive patients in a prospective study, Doppler ultrasound provided clinical information that could not be obtained with echocardiographic studies alone. The advantages of this technique for noninvasive cardiac studies are now being recognized in the general medical community. The results of ongoing clinical investigations will help define the role of Doppler echocardiography as a clinically useful diagnostic tool for cardiac evaluation.

Cardiovascular Physiological Phenomena↗

B5, a new B cell-restricted activation antigen.

The characterization of a new human B cell-restricted activation antigen (B5) is described in this report. With the use of a monoclonal antibody to B5, we show that B5 can be detected on peripheral blood or splenic B cells after 1 day of stimulation with either anti-immunoglobulin, protein A, Epstein Barr virus, or pokeweed mitogen. In contrast, B5 was not expressed on resting B, T, or myeloid cells. More important, B5 could not be detected on activated T cells or monocytes. The B5 antigen was expressed on some lymphoblastoid B cell lines and B cell neoplasms but was not expressed on leukemias or lymphomas of T or myeloid origin. The B5 antigen is distinct from previously reported B cell activation antigens by its m.w. and pattern of cellular expression. These studies suggest that B5 is a novel B cell-restricted activation antigen, which may be useful to study the events of early human B cell activation.

Animals↗

Studies of in vitro activation and differentiation of human B lymphocytes. I. Phenotypic and functional characterization of the B cell population responding to anti-Ig antibody.

Investigation of the activation of splenic B cells by anti-immunoglobulin (Ig) antibody has enabled us to characterize the anti-Ig-responsive B cell and to analyze the phenotypic changes which accompany proliferation and differentiation. The anti-Ig antibody-responsive B cell population was characterized by the expression of high levels of the B2 antigen and represented approximately 40% of splenic B cells. Brisk mitogenesis which peaked at 3 to 4 days was induced by anti-Ig antibody. The proliferative phase was characterized phenotypically by a dramatic decline in B2 antigen expression, with most cells showing no detectable B2 by 4 days post-activation. The other hallmark of this phase was de novo expression of a group of "activation antigens." These included the B cell-restricted antigens B-LAST 1, BB1, and B5, and the T cell-associated interleukin 2 receptor and T12 antigens. Concomitantly, B1, B4, and Ia expression increased, the increase being roughly proportional to the increase in cell size. After day 4, the mitogenic response progressively diminished, while Ig synthesis increased. During this differentiation phase, cell surface antigens again displayed a distinct sequence of changes. The five activation antigens and the B1, B4, and Ia antigens began to decrease. However, two markers, T10 and PCA-1, which are found on plasmacytomas, appeared and their level of expression steadily increased. These changes and the appearance of morphologically identifiable plasma cells required the presence of T cells in this system. T cell supernatants alone induced Ig secretion but did not induce expression of PCA-1 or the appearance of cells with plasma cell morphology. The culture system developed in this study has allowed us to analyze the antigenic changes following activation by anti-Ig antibody. This sequence of changes has not only permitted the identification of antigens which, by their appearance at distinct stages may have an important role in proliferation and differentiation of B cells, but also provides us with the means of studying the function of each antigen.

Animals↗

Hairy cell leukemia: a tumor of pre-plasma cells.

Monoclonal antibodies defining B-, T-, and myeloid-restricted cell surface antigens were used to characterize the lineage and state of differentiation of tumor cells isolated from 22 patients with hairy cell leukemia (HCL). These tumors were shown to be of B lineage because they strongly expressed the B cell-restricted antigens B1 and B4 and lacked T cell- and monocyte-restricted antigens. Moreover, the strong expression of the plasma cell-associated PCA-1 antigen on the majority of hairy cells suggested that these tumors correspond to later stages of B cell ontogeny. Dual fluorescence experiments further confirmed that HCL splenocytes that coexpressed B1 and PCA-1 demonstrated both the morphology and tartrate-resistant acid phosphatase positivity of hairy cells. The observation that some hairy cells either spontaneously produce immunoglobulin (Ig) or could be induced to proliferate and secrete Ig provides complementary support for the view that HCL is a pre-plasma cell tumor. However, staining of hairy cells with anti-IL2R1 monoclonal antibody, which is directed to the T cell growth factor receptor and/or with the anti-Mo1 reagent, directed to C3bi complement receptor, distinguish these cells from currently identified B cells.

Antibodies, Monoclonal↗

Immunologic heterogeneity of diffuse large cell lymphoma.

The cellular lineage of 57 diffuse large-cell lymphomas (DLCLs) was determined using a panel of monoclonal antibodies directed against lineage-restricted and -associated T, B, and monocyte antigens. The majority (82%) were of B cell lineage as determined by the expression of sig and/or B1, with the remaining 16% being of T cell lineage and 2%, of monocyte-myeloid lineage. By the expression of other B cell-restricted and -associated antigens, two major and two minor subgroups could be identified. These subgroups expressed the following phenotypes: (1) B1+B4+sIG+B2- (51%); (2) B1+B4+sIg+B2+ (29%); (3) B1+B4+sIg-B2+ (10%); and (4) B1+B4-sIg+B2- (10)%. The morphology of transformed lymphocytes, the weak to absent expression of the early B cell antigens B2 and sIgD, and the absence of the late B cell differentiation antigens PCA-1 and PC-1 suggested that these tumors were the neoplastic counterparts of normal B cells at the mid-stages of differentiation. Further support for the notion that B-DLCLs correspond to transformed B lymphocytes was concluded from the observation that B cells could be identified in normal spleen that expressed the cell surface phenotype and morphological appearance of the majority of B-DLCLs.

Antibodies, Monoclonal↗

Isolation and functional analysis of human B cell populations. I. Characterization of the B1+B2+ and B1+B2- subsets.

Distinct populations of human B lymphocytes can be identified by their expression and/or co-expression of the B cell-restricted antigens B1 and B2. Dual fluorochrome staining and flow cytometric cell sorting permitted the isolation of the B1+B2+ and B1+B2- cells to homogeneity. In contrast, very few B1-B2+ cells were obtainable from normal lymphoid organs. Virtually all B1+B2+ cells expressed IgM and IgD, but lacked IgG and the plasma cell antigens PCA-1 and PC-1, whereas the B1+B2- cells more frequently expressed IgG, PCA-1 and PC-1. Both populations were noncycling and were composed of similar percentages of small and large cells. The B1+B2+ cells proliferate to anti-mu or to anti-mu + PHA-LCM, but not to PHA-LCM alone. They require both T cells and PWM to produce Ig. In contrast, B1+B2-cells do not significantly proliferate to anti-mu, PHA-LCM, or anti-mu and PHA-LCM. They produce Ig in response to T cells alone without PWM. These phenotypic and functional observations provide preliminary evidence that these populations are distinct and that the B1+B2+ cell may be a "resting" B cell, whereas the B1+B2- cell appears to be more "differentiated." The present studies further suggest that they will also be helpful in characterizing B cells in some human disease states. We believe that the identification and isolation of these and similar subsets of B cells defined by differing cell surface phenotype should aid our understanding both of normal B cell differentiation and of B cell disease states.

Acquired Immunodeficiency Syndrome↗

Structural and functional characterization of IL 2 receptors on activated human B cells.

After activation, B cells express the IL 2 receptor as determined by their reactivity with monoclonal anti-IL 2 receptor antibodies. In this report we show that anti-IL 2 receptor antibodies precipitated comparable 60,000 to 65,000 dalton proteins from highly purified B and T cells. Limited peptide mapping suggested that the receptors on B and T cells were identical. Moreover, activated B cells could be induced to proliferate by IL 2, but not to secrete Ig. Anti-IL 2R antibody blocked the effect of IL 2 but not the proliferative response induced by B cell growth factor (BCGF), suggesting independent growth factor receptors. Investigation of the kinetics of the B cell response to growth factor indicated that BCGF acts within 24 hr, whereas IL 2 was virtually devoid of activity for 48 hr. Nevertheless, after 72 to 96 hr, the effect of IL 2 was equal to or greater than that obtained with BCGF. These studies suggest that the initial stages of B cell proliferation involves a sequential interaction of BCGF and IL 2 with their respective receptors.

Antibodies, Monoclonal↗