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Biomedical subjects

R S Stein

Publications and source records attributed to R S Stein.

At least 19 recordsLinked to original sources
PubMed1999

High-dose therapy with autologous or allogeneic transplantation as salvage therapy for small cleaved cell lymphoma of follicular center cell origin.

Between 1985 and 1996, 51 patients with relapsed or refractory small cleaved cell lymphoma (SCCL) received high-dose chemotherapy +/- TBI in conjunction with autologous (ABMT) (36 patients) or allogeneic transplantation (15 patients). Patients were eligible for ABMT if the bone marrow biopsy done prior to the planned transplant did not reveal microscopic involvement with SCCL. Patients receiving ABMT had a median age of 48 years, had received a median of 2.5 chemotherapy regimens prior to transplantation, and were transplanted a median of 35.5 months from diagnosis. Among patients receiving ABMT, 5 year actuarial survival was 56+/-11%. Median survival was 126+ months, and median survival from diagnosis was 191 months. Univariate and multivariate analysis identified sensitive disease as the best predictor of a favorable response. Five-year actuarial survival was 66+/-12% for patients with sensitive disease at the time of transplant as compared to 29+/-17% for patients with resistant disease, P = 0.015. Median survival in patients with sensitive disease at the time of ABMT was 126+ months. By univariate analysis, survival was significantly better for patients receiving ABMT as compared to patients receiving allogeneic transplants. Median survival following allogeneic transplantation was 5 months; 5 year actuarial survival was 15+/-13%. In a multivariate analysis, which considered autologous vs allogeneic transplantation, sensitive vs resistant disease, <3 vs > or = 3 prior treatments, and prior bone marrow involvement, allogeneic transplantation was significantly associated with poor survival. Treatment-related mortality occurred in eight of 15 patients receiving allogeneic transplantation and limited the effectiveness of this therapy. High-dose therapy in conjunction with ABMT is effective therapy for patients with SCCL whose disease is sensitive to chemotherapy and whose marrows are microscopically free of disease. Because of possible selection bias, it has not been proven that this approach increases survival in these patients. Treatment-related mortality limits the effectiveness of allogeneic transplantation in SCCL.

Adult↗
PubMed1996

Effects of chemical disinfectant solutions on the stability and accuracy of the dental impression complex.

Currently available impression materials were not designed for disinfection or sterilization, and it is conceivable that disinfectants may adversely affect impressions. This study evaluated the accuracy and dimensional stability of polyether (Permadyne/Impregum) and polyvinyl siloxane (Express) impression materials retained by their adhesives in two different acrylic resin tray designs (perforated and nonperforated) when the materials were immersed for either 30 or 60 minutes in three high-level disinfectants. Distilled water and no solution served as controls. A stainless steel test analog similar to ADA specification No. 19 was used. A total of 400 impressions were made with all combinations of impression materials, tray designs, disinfectant, and soaking times. Samples were evaluated microscopically before and after immersion and 48 hours after soaking. Results indicated that these two impression materials were dimensionally stable. Because the results emphasized the stability and accuracy of the impression complex under various conditions, dentists can perform disinfection procedures similar to the protocol of this study without concern for clinically significant distortion of the impression.

Analysis of Variance↗
PubMed1996

Nocardial infections in bone marrow transplant recipients.

Infections caused by Nocardia species have been infrequently described in bone marrow transplant (BMT) recipients. We reviewed six cases of nocardiosis occurring in our population of BMT recipients and the four cases previously reported in the literature. The rate of nocardial infection at our institution was 0.2% (1 of 554) among autologous BMT recipients and 1.7% (5 of 302) among allogeneic BMT recipients (odds ratio, 9.3 [95% confidence interval, 1.1-80.1]; P = .046). All 10 patients had received immunosuppressive medications, and all but one allogeneic BMT recipient had acute or chronic graft-vs.-host disease (GVHD). Four patients had extensive exposure to soil or dust before nocardiosis developed. Seventy percent of the patients died, but death was less often due to progressive nocardial infection than to complications of GVHD and associated invasive infection with Aspergillus species. Three patients had nocardiosis despite receiving prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMZ) on an intermittent basis two or three times a week. These data show that nocardial infection is an important if infrequent complication of bone marrow transplantation and is associated with a high rate of invasive fungal infection. TMP-SMZ prophylaxis given intermittently does not reliably protect against infection.

Adult↗
PubMed1996

Etoposide and mitoxantrone as a second cycle of consolidation therapy following high dose cytosine arabinoside and daunorubicin in patients with acute non-lymphocytic leukemia in remission: a pilot study.

High dose cytosine arabinoside (ARA-C) has produced long term relapse free survival in 26% to 49% of patients when used as consolidation therapy of acute non-lymphocytic leukemia (ANLL) in first remission. However, the optimal consolidation regimen has not been defined. In this pilot study we attempted to confirm and extend our previous studies of high dose consolidation therapy by administering two cycles of consolidation chemotherapy to patients with ANLL in first remission. The first cycle was high dose ARA-C 3 gm/m2 over 1 hour every 12 hours for 12 doses followed by daunorubicin 45 mg/m2/day for three days. The second cycle was etoposide 75 mg/m2/day for 10 days and mitoxantrone 12 mg/m2/day for three days. Twenty-three patients received high dose consolidation chemotherapy, 13 of whom received the proposed two cycles. The major reason for not receiving the planned second consolidation cycle was life threatening toxicity, primarily fungal infection, during the first consolidation cycle. By actuarial estimate, 46% of patients receiving consolidation chemotherapy were projected to be relapse free at 36 months. There were no deaths during consolidation. Survival was not improved in patients receiving etoposide and mitoxantrone as the second cycle of consolidation therapy as compared to patients receiving only one cycle of consolidation therapy.

Adult↗
PubMed1995

T-cell-rich B-cell lymphomas: diagnosis and response to therapy of 44 patients.

PURPOSE: Clinicopathologic features of 44 patients with well-documented T-cell-rich B-cell lymphomas (TCRBCLs) were reviewed to determine if there were distinguishing clinical characteristics and to evaluate the responsiveness to therapy. PATIENTS AND METHODS: Forty-one patients had de novo TCRBCL, while three patients had a prior diagnosis of diffuse large B-cell lymphoma. Seventeen TCRBCLs were identified from a retrospective analysis of 176 lymphomas diagnosed before 1988 as peripheral T-cell lymphoma (PTCLs). The initial pathologic diagnosis was incorrect in 36 of 44 cases (82%), usually due to the absence of adequate immunophenotypic and/or genotypic studies at the initial study. RESULTS: The median age of patients was 53 years (range, 17 to 92), and the male-to-female ratio was 1.4:1. B symptoms were present in 22 of 41 patients (54%); splenomegaly was detected in 11 patients (25%). Clinical stage at diagnosis was as follows: I (n = 8), II (n = 6), III (n = 15), IV (n = 14), and unstaged (n = 1). Although therapy was heterogeneous, the disease-free survival (DFS) and overall survival (OS) rates at 3 years for patients with de novo TCRBCL were 29% and 46%, respectively. A complete response (CR) to combination chemotherapy for intermediate-grade lymphomas was observed in 16 of 26 patients (62%); 11 of these patients (42%) had a continuous CR, compared with one of 14 patients (7%) who received radiation therapy or therapy for low-grade lymphoma or Hodgkin's disease (HD) (P < .05). However, there was no difference in OS between patients who received chemotherapy for intermediate-grade lymphoma versus other therapies (49% v 48%) due to a high response rate to salvage therapies, including seven patients without disease after marrow transplantation. CONCLUSION: TCRBCLs are difficult to recognize without immunoperoxidase studies. Patients with TCRBCL have clinical features similar to patients with other large B-cell lymphomas, except they may have more splenomegaly and advanced-stage disease; they should receive combination chemotherapy directed at large-cell lymphomas.

Adolescent↗
PubMed1995

Graft-versus-host-disease prophylaxis for matched unrelated donor bone marrow transplantation: comparison between cyclosporine-methotrexate and cyclosporine-methotrexate-methylprednisolone.

We performed a sequential study comparing two regimens, cyclosporine-methotrexate (CsA-MTX) and cyclosporine-methotrexate-methylprednisolone (CsA-MTX-MP) for graft-versus-host disease (GVHD) prophylaxis in patients undergoing matched unrelated donor bone marrow transplantation (MUD BMT). Study end-points were the development of GVHD, various infectious complications and survival. Twenty nine patients with malignant hematologic disease without HLA-compatible family donors were treated between May 1990 and November 1993. All donors were volunteers from the National Marrow Donor Program (NMDP) serologically HLA-A-A, B and DR identical. MLC reactivity and high resolution DR DNA typing were not used to exclude donors. Sixteen patients received CsA-MTX and 13 patients received CsA-MTX-MP. CsA and MTX doses were the same in both groups: CsA 1.5 mg/kg i.v. over 2h every 12h beginning the day prior to transplant (day-1) and MTX 10 mg/m2 i.v. bolus on days +1, +3 and +6 with leucovorin on days +2, +4 and +7. MP was administered at a dose of 0.25 mg/kg i.v. every 12h beginning on day +7 and increased to 0.5 mg/kg on day +14. Beginning on day +35 MP and CsA were tapered 5% per week with targeted discontinuation at 6 months. Both groups were comparable for primary disease, preparative regimen, recipient age (median 33 VS 33 years), donor age (median 39 vs 39.5 years), donor-recipient sex, donor ABO mismatch and serologic CMV positivity. All patients received similar supportive care.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Evaluation of soldered connectors of two base metal ceramic alloys.

Soldered connectors for two base metal ceramic alloys (nickel-chromium and cobalt-chromium) were compared by use of four different techniques: (1) infrared preceramic soldering, (2) gas and oxygen preceramic soldering, (3) porcelain furnace postsoldering under vacuum, and (4) porcelain furnace postsoldering without vacuum. A control group was established with solid cast specimens of each alloy. No statistically significant difference was noted between infrared and torch preceramic soldering techniques for either of the two alloys. However, the joints postsoldered under vacuum were significantly superior to postsoldered connectors without vacuum (p < 0.0001). No significant differences were observed among techniques 1, 2, and 3, although the three groups were substantially superior to technique 4 for both alloys (p = 0.05). The control group for both alloys was appreciably stronger than the soldered groups (p < 0.0001), and the nickel-chromium samples within the control group were significantly stronger than the Co-Cr samples.

Analysis of Variance↗
PubMed1994

Treatment of aplastic anemia with an investigational antilymphocyte serum prepared in rabbits.

The authors evaluated antilymphocyte serum prepared in rabbits (ALS-R) as an alternative to antilymphocyte serum prepared in horses (ALG-H) in the therapy of aplastic anemia. Between 1980 and 1993, 57 evaluable patients received ALS-R and prednisone +/- cyclosporine +/- androgens. Standard response criteria were used and patients were evaluated at 3 months from the start of therapy. Median age was 43 years. Disease was present for up to 2 months in 24 patients, 2-5 months in 14 patients, and 6 months or more in 19 patients. Disease was severe in 30 patients and moderate in 27. Responses occurred in 16 (28%) of 57 patients. Responses were more frequent in females, in patients treated within 6 months of diagnosis, and in patients with severe disease. Among patients receiving ALS-R and cyclosporine within 2 months of diagnosis, 46% responded. After ALS-R therapy, 20 patients received ALG-H; 8 (40%) of 20 responded. Eight patients receiving ALS-R previously had received ALG-H; 2 (25%) of these 8 patients responded. Toxicity of ALS-R was minimal. Antilymphocyte serum prepared in rabbits, in conjunction with other immunosuppressive agents, represents an effective alternative to ALG-H in aplastic anemia, especially in patients previously treated with ALG-H.

Adolescent↗
PubMed1993

Comparative analysis of two techniques for soldered connectors.

The aim of this study was to compare and analyze gas torch and an infrared technique as a heat source. Ney Oro B2, Ney Eclipse and Ney 76 alloys were selected for this purpose. Sixty standardized rods were invested, cast, and sectioned from their respective sprue buttons. The rods were then invested for soldering and sectioned at their midpoints. Ten specimens of each alloy were soldered with the gas torch flame. The Instron universal testing device was used to test the flexural strength of the resultant joints. Fractured specimens were analyzed under electron microscopy.

Dental Alloys↗
PubMed1993

A comparative analysis of the accuracy of implant transfer techniques.

Four different implant transfer techniques using two master cast systems (solid cast and Zeiser system) were evaluated and compared with respect to the accuracy with which abutment positions were reproduced. A stainless steel experimental analogue with two anterior and two posterior fixtures and abutments was fabricated. Polyether impressions (14 each) were made by use of four techniques, (I) nonsplinted, (II) splinted with dental floss and acrylic resin, (III) splinted with orthodontic wire and acrylic resin, and (IV) splinted with acrylic resin alone. The fourteen impressions of each technique were divided into two equal groups: group 1, solid cast system, and group 2, Zeiser system. The abutments of each master cast were measured vertically and horizontally with a profile projector. Statistical analysis indicated no significant difference between the splinted and nonsplinted techniques. The Zeiser system provided more accurate interabutment relationships for the posterior region than the solid cast system.

Acrylic Resins↗
PubMed1993

Effective therapy for poor-prognosis non-Hodgkin's lymphoma with 8 weeks of high-dose-intensity combination chemotherapy.

PURPOSE: Despite substantial advances in the treatment of aggressive non-Hodgkin's lymphoma, therapeutic results with conventional regimens remain poor in some subsets of patients. In an attempt to improve the prognosis of such patients we used an 8-week, multidrug chemotherapy regimen of high dose-intensity. PATIENTS AND METHODS: Between April 1986 and April 1991, 70 patients with advanced intermediate- or high-grade non-Hodgkin's lymphoma were treated. The median age was 41 years (range, 18 to 69). Fifty-one patients (73%) had stage IV disease; 37 (53%) were Shipp's category 3; 17 (24%) had small noncleaved-cell lymphoma; 35 (50%) had Eastern Cooperative Oncology Group (ECOG) performance status > or = 2; 24 (34%) had two or more extranodal sites involved; and 17 (24%) had bone marrow involvement. The 8-week regimen included cyclophosphamide, etoposide, doxorubicin, vincristine, bleomycin, methotrexate with leucovorin rescue, and prednisone. RESULTS: Sixty-two of 70 patients completed the regimen as planned. Fifty-seven patients (81%) obtained a complete response (CR) and the actuarial 5-year failure-free survival rate is 52%. Thirty-seven patients remain alive and disease-free a median of 35 months (range, 7 to 68) after therapy. Adverse prognostic factors included age more than 50 years, bone marrow involvement, and serum lactic dehydrogenase (LDH) more than 500 IU/L (normal range, 125 to 250). Myelosuppression was responsible for most of the treatment-related toxicity. Severe leukopenia (< 1,000/microL) occurred in all patients and lasted a median of 9 days. Seven patients (10%) died of myelosuppression-related complications; five of these patients were older than 60 years. CONCLUSION: This brief but intensive therapy was effective in treating poor-prognosis patients with non-Hodgkin's lymphoma. With this therapy, patients with small noncleaved-cell lymphoma or Shipp's category 3 disease had treatment outcome similar to the group as a whole. This therapy was not well tolerated by patients older than 60 years, and should not be given to this subgroup. Verification of these results in a randomized trial setting is indicated.

Adolescent↗
PubMed1992

Root fracture in endodontically treated teeth related to post selection and crown design.

Standardized plastic analogues simulating an endodontically treated maxillary central incisor root were used to investigate the resistance to root fracture in endodontically treated teeth. Three different post and core systems were used: (1) cast post and core, (2) Para-Post Plus post, and (3) Flexi-Post post. The core build-up material selected in this study was Ketac Silver material, after which a crown preparation was made on each analogue. Two types of preparations were used: a wide chamfer margin (butt-joint) and a wide chamfer margin with a 1.0 mm circumferential bevel. An overcasting was fabricated and was permanently cemented on each preparation. Assemblies were subjected to an increasing lingual oblique force until fracture occurred. Results were tabulated using the analysis of variance (F test) and Student's t test. Beveled preparations with a concomitant final restoration provided a significant increased resistance to root fracture. Furthermore, vertical fracture occurred twice as often with nonbeveled preparations.

Analysis of Variance↗
PubMed1992

T-cell-rich B-cell lymphomas. A clinicopathologic study of 19 cases.

T-cell-rich B-cell lymphomas (TCRBCLs) are recently described, unusual non-Hodgkin's lymphomas that have a diffuse morphology, a predominance of reactive T-cells, and a minority of neoplastic B-cells. The clinical and pathological features of 19 TCRBCLs, all of which demonstrated B-cell clonality, are presented. These lymphomas generally affected older patients by widespread disease and usually were nodal in origin. Treatment varied, but continuous complete remissions (eight patients) were achieved only in those receiving chemotherapy directed at intermediate-grade lymphomas. Although morphologically heterogeneous, all cases resembled peripheral T-cell lymphomas (PTCLs); several TCRBCLs also contained Reed-Sternberg-like cells. Flow cytometry or frozen-section immunoperoxidase failed to detect monotypic immunoglobulin (Ig) in eight of eight cases tested. In contrast, paraffin immunoperoxidase was very useful diagnostically, showing large L26 (CD20-associated) positive cells scattered singly or in small clusters among numerous small T-cells (UCHL1[CD45RO] positive) in all cases. Monotypic cytoplasmic Ig was present in 16 of 19 cases, one of which exhibited plasmacytic differentiation. Southern blot analysis demonstrated relatively faint Ig JH and/or JK bands, indicating a small monoclonal B-cell population in nine of 11 cases, one of which also showed a bcl-2 rearrangement. No T-cell receptor gene rearrangements were observed. These results showed that TCRBCLs may be easily confused with PTCLs or occasionally confused with Hodgkin's disease. TCRBCLs are probably heterogeneous biologically; some cases are of follicular center cell origin. These lymphomas respond to chemotherapy directed at intermediate-grade lymphomas, apparently have a better prognosis than PTCLs, and seem to represent morphological variants of different types of large B-cell lymphomas.

Adolescent↗