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Biomedical subjects

S O'Brien

Publications and source records attributed to S O'Brien.

At least 91 records · Page 5Linked to original sources
PubMed1997

Long-term follow-up results of alpha-interferon-based regimens in patients with late chronic phase chronic myelogenous leukemia.

The aim of this analysis was to evaluate the efficacy of alpha-interferon (alpha-IFN) regimens in late chronic phase (diagnosis >12 months) chronic myelogenous leukemia (CP-CML). Long-term follow-up results were evaluated in 137 patients with Philadelphia chromosome (Ph)-positive late CP-CML. The alpha-IFN programs were sequential studies with human leukocyte alpha-IFN (seven patients), recombinant alpha-IFN alone (15 patients) or with IFN-gamma (29 patients), hydroxyurea (HU) (19 patients), or low-dose cytarabine (Ara-C) (67 patients). Overall, 57% of the patients achieved complete hematological response (CHR), and 7% obtained partial hematological response. Nineteen patients (15% of the 123 evaluable patients) had a cytogenetic response which was major (Ph-positive <35%) in 10 patients (8%). A trend for better responses was observed with shorter disease duration. The median overall survival from start of therapy was 49 months, with an estimated 5-year survival rate of 41%. Some common pretreatment prognostic factors associated with response did not show statistical associations when applied in late CP-CML; however, characteristics such as smaller spleen size, and lower percentages of peripheral blood and marrow blasts and basophils were associated with better survival experience. When patients were subgrouped according to risk, no significant differences in the incidence of cytogenetic response and in survival outcomes were observed among various risk groups. This study confirms that alpha-IFN-based regimens have a modest activity in late CP-CML, and supports the need to develop investigational strategies aimed at improving patient prognosis in this phase.

Adolescent↗
PubMed1997

Treatment of neutropenia-related fungal infections with granulocyte colony-stimulating factor-elicited white blood cell transfusions: a pilot study.

Neutropenia-related fungal infections can be life-threatening despite antifungal therapy. We evaluated the role of recombinant granulocyte colony-stimulating factor (rG-CSF)-elicited white blood cell (WBC) transfusions in patients with neutropenia-related fungal infections. Adult patients with hematologic malignancies, absolute neutrophil counts (ANC) <500/microl and fungal infections refractory to amphotericin B, received daily transfusions of rG-CSF-elicited and irradiated WBC transfusions from related donors. Donors received 5 microg/kg/day of rG-CSF subcutaneously. Donors achieved a mean ANC of 29.4 x 10(3) per microliter. The mean yield of neutrophils per transfusion was 41 x 10(9) (range, 10-116). Fifteen patients received a median of eight transfusions (range, 3-16). Fourteen patients had received rG-CSF for a median of 12 days. The median ANC baseline was 20/microl. Eleven patients had favorable responses and eight of them remained free of infection 3 weeks after therapy. Favorable responses occurred among patients with better Zubrod performance status (median, 3 vs 4) and shorter duration of both profound neutropenia (median, 15 vs 25 days) and active infection (median, 8 vs 17 days). The mean 1- and 24-h post-transfusion ANCs were 594/microl (range, 98-1472/microl) and 396/microl (range, 50-1475/microl), respectively. Adverse reactions were observed in nine of 35 donors and in the recipients of six of 130 transfusions. rG-CSF-elicited WBC transfusions may be a safe and promising approach for treating neutropenia-related fungal infections.

Adolescent↗
PubMed1997

Fludarabine and granulocyte colony-stimulating factor (G-CSF) in patients with chronic lymphocytic leukemia.

The study was designed to determine whether administration of granulocyte colony-stimulating factor (G-CSF) following fludarabine would reduce the incidences of myelosuppression and infections. Twenty-five previously treated patients with Rai stage III-IV chronic lymphocytic leukemia (CLL) received fludarabine 30 mg/m2 daily for 5 days each month. G-CSF was given at 5 microg/kg subcutaneously starting 1 day after chemotherapy (day 6) and continued until the next course unless the granulocyte count was > or =10000/microl. The incidences of myelosuppression and infection were compared with those seen in an historical control population of 145 previously treated patients with Rai stage III-IV CLL who were given the same schedule of fludarabine without growth factor. There was a significant decrease in myelosuppression; patients receiving G-CSF developed neutropenia at a neutrophil count <1000/microl or 500/microl in 45% and 15% of courses vs 79% (P=0.002) and 63% (P < 0.001) of historical controls. Twenty percent of G-CSF-treated patients had therapy delayed by >35 days per course, vs 50% of historical controls (P=0.005). The incidence of pneumonia was 8% with G-CSF and 37% without in historical controls. Other infection rates (sepsis, fever of undetermined origin, minor infections) were similar. This decrease in pneumonia was noted even in high-risk groups such as patients older than 60 years and patients with hypogammaglobulinemia. The use of G-CSF following fludarabine in high-risk patients with CLL resulted in a significant decrease in myelosuppression and pneumonia. Larger trials to verify these results and to compare costs are indicated.

Adult↗
PubMed1997

The hyper-CVAD regimen improves outcome in relapsed acute lymphoblastic leukemia.

Sixty-six adults with refractory acute lymphocytic leukemia received salvage therapy with the 'hyper-CVAD' regimen, consisting of eight courses of alternating intensive chemotherapy with growth factor support, followed by oral maintenance chemotherapy. Their outcome was compared with 63 prognostically similar historical control patients treated with high-dose Ara-C plus mitoxantrone with or without GM-CSF. Overall, the complete response rates were similar in the treatment and control groups (29 of 66 (44%) vs 24 of 63 (38%)). There were more patients in the current study with primary resistant disease (10 of 66 (15%) vs one of 63 (2%), P = 0.006), and conversely fewer patients with secondary resistance (19 of 66 (29%) vs 28 of 63 (44%), P = 0.06). Recovery of granulocyte counts above 500/microl was significantly faster in the current study when compared to high-dose Ara-C-treated patients who were given GM-CSF (20 vs 25 days, P = 0.04). Survival was prolonged in the hyper-CVAD-treated patients, with most of the benefit seen in first salvage patients (42 vs 20 weeks, P = 0.016). When only first salvage patients were considered, there was a significant difference in disease-free survival in favor of hyper-CVAD (52 vs 20 weeks, P = 0.008). The hyper-CVAD regimen is a more effective and less toxic salvage regimen for relapsed acute lymphocytic leukemia than high-dose Ara-C-based regimens.

Adult↗
PubMed1997

Allogeneic blood or marrow transplantation for chronic lymphocytic leukaemia: timing of transplantation and potential effect of fludarabine on acute graft-versus-host disease.

The outcome of allogeneic haemopoietic transplants including the rate of immune complications for patients with chronic lymphocytic leukaemia (CLL) refractory to or relapsing after chemotherapy with fludarabine was analysed. Fifteen patients with advanced CLL who received allogeneic transplantation were prospectively analysed. All patients had previously received chemotherapy with fludarabine for 3-15 courses; 12 were refractory. The median number of circulating CD4+ and CD8+ lymphocytes at the time of transplant was 0.49 x 10(9)/l and 0.23 x 10(9)/l, respectively. One patient was transplanted from a one HLA-antigen mismatched unrelated donor. Three others received a one or two antigen mismatched graft and 11 had HLA-identical sibling donors. Patients received cyclosporine or tacrolimus in addition to methotrexate or methylprednisolone for prophylaxis of acute graft-versus-host disease (aGVHD). Fourteen patients engrafted; one patient had graft failure, but recovered after therapy with intravenous immunoglobulin. 13 (87%) achieved complete remission (CR). Nine (53%) remain alive and in CR with a median follow-up of 36 (range 3-60) months. None developed visceral graft-versus-host disease. These data compared favourably to published reports in other leukaemia patients and for patients with CLL who received a comparable immunosuppressive therapy but without prior fludarabine exposure. This data indicates that allogeneic haemopoietic transplantation can induce durable remission in patients with CLL refractory to fludarabine and that it is reasonable to delay transplantation until failure of fludarabine therapy. It also suggests that prior exposure to fludarabine may decrease the incidence of severe aGVHD, possibly through its immunosuppressive effects. Further studies are warranted to evaluate this observation.

Adult↗
PubMed1997

Risk factors for reported elder abuse and neglect: a nine-year observational cohort study.

To determine longitudinal risk factors for elder abuse and neglect, an established cohort of community-dwelling older adults (n = 2,812) was linked with elderly protective service records over a 9-year follow-up period. Protective services saw 184 (6.5%) individuals in the cohort for any indication, and 47 cohort members were seen for corroborated elder abuse or neglect for a sampling adjusted 9-year prevalence of 1.6% (95% CI 1.0%, 2.1%). In pooled logistic regression, age, race, poverty, functional disability, and cognitive impairment were identified as risk factors for reported elder mistreatment. Additionally, the onset of new cognitive impairment was also associated with elder abuse and neglect. Because the mechanism of elder mistreatment case-finding in this study was a social welfare system (protective services), the influence of race and poverty as risk factors is likely to be overestimated due to reporting bias.

Activities of Daily Living↗
PubMed1997

Injuries among children in home and out-of-home care.

UNLABELLED: As the number of children receiving care in out-of-home settings increases in the United States, the risk of injury in such settings has become the subject of intense research. OBJECTIVES: This study examined the relative safety of out-of-home care compared with care in a child's own home. METHODS: This community based prospective cohort study of 656 families in three adjacent counties in the Piedmont region of North Carolina characterizes the patterns and rates of injuries among children less than 5 years of age in three child care settings, home care (HC), center based care (CBC), and other out-of-home care (OOHC). Information about minor and severe injuries was obtained from parents using monthly telephone interviews over a one year period. Statistical modeling designed to handle unbalanced data with correlated observations was used as the primary tool for analysis. RESULTS: Rate of minor injuries was highest in CBC, followed by HC, and then OOHC. However, these differences for OOHC may have been due to reporting biases and errors in rate estimates. There were no significant differences in severe injury rates among the three settings. CONCLUSIONS: The risk of serious injury among children under 5 in CBC is not different from that of children in HC or OOHC despite the fact that the risk of minor injury is higher.

Accidents, Home↗
PubMed1997

Second cancer risk in hairy cell leukemia: analysis of 350 patients.

PURPOSE: The discovery of effective therapy for hairy cell leukemia (HCL) has increased the relevance of long-term outcome. We have therefore examined the incidence of second cancers. PATIENTS AND METHODS: Data on 350 HCL patients was obtained from the M.D. Anderson Cancer Center Cancer Registry's computerized data base and from chart review. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) (observed/expected [O/E]) were calculated with the expected number determined using age, sex, and calendar-year-specific rates from the Connecticut Tumor Registry and from national mortality data, respectively. RESULTS: The median age of the patients was 50 years and the median follow-up duration was 6 years. Twenty-six patients developed a second cancer at least 6 months after the HCL diagnosis (O/E ratio, 1.34; P = .08). There was no excess of malignancy among patients treated with interferon alfa (IFN-alpha; P = .27), 2-chlorodeoxyadenosine (2CDA; P = .37), or deoxycoformycin (DCF; P = .7). However, an excess of myeloma-related neoplasms (O/E, 13.04; P < .001) and lymphomas (O/E, 8.7; P = .03) was observed. Survival from the advent of systemic therapy for HCL was better than before this time (P = .0009). Nevertheless, mortality remained excessive (O/E, 6.17; P < .001), mainly because of HCL-related infections and secondary malignancy. CONCLUSION: Among 350 patients with HCL, there was an increase in the number of second cancers; however, it did not reach statistical significance and was not associated with therapy. The incidence of lymphoid neoplasms was significantly higher than expected. Survival since the advent of effective systemic therapy was excellent, although excess mortality was still observed.

Adult↗
PubMed1997

Remission of posttransplant lymphoproliferative disorder after interferon alfa therapy.

Posttransplant lymphoproliferative disorder (PTLD) is one of the major complications of immunosuppressive therapy. PTLD is strongly associated with the Epstein-Barr virus (EBV). It is believed that EBV-infected B cells proliferate in an unchecked manner due to suppression of cytotoxic T cells and elevation of B cell-promoting cytokines. There is no consensus on the treatment of PTLD other than reduction of immunosuppressive therapy. We report a case of PTLD with monoclonal B cells confined to the lymph nodes. The patient did not initially respond to reduction of immunosuppression, oral acyclovir, and intravenous immunoglobulin injection. She subsequently responded when subcutaneous injections of interferon alfa (5 million U) were given three times a week. The patient received a 3-mo course of interferon and remained in remission 12 mo after treatment. Her graft function was well maintained, and cyclosporin A was restarted 2 mo after achieving remission. The clinical manifestations, risk factors, pathogenesis, and treatment of PTLD, as well as 12 previously reported cases of PTLD treated with interferon, were reviewed. On the basis of the results presented here, it appears that interferon alfa may be useful in treating PTLD and that there is a need for further clinical trials.

Aged↗
PubMed1997

Chronic myelogenous leukemia--progress at the M. D. Anderson Cancer Center over the past two decades and future directions: first Emil J Freireich Award Lecture.

The purpose of this study was to review the progress in clinical and translational research in chronic myelogenous leukemia (CML) over the past 20 years at M.D. Anderson Cancer Center. The CML database updating the clinical and basic research investigations was reviewed as the source of this report. Publications resulting from these investigations were summarized. The long-term results with intensive chemotherapy, IFN-alpha therapy alone or in combination, autologous stem cell transplantation, and new agents such as homoharringtonine and decitabine showed encouraging results. Biological studies related to the BCR-ABL molecular abnormality, other molecular events, and the detection of minimal residual disease were detailed. Future strategies with potential promise in CML were outlined. Significant progress in understanding CML biology and in treating patients afflicted with the disease has occurred. Several therapeutic and research tools are currently investigated, which should hopefully improve further the prognosis of patients with CML.

Antineoplastic Agents↗
PubMed1997

Studies of decitabine with allogeneic progenitor cell transplantation.

The aim was to determine the efficacy and safety of decitabine in the settings of relapse post-allogeneic progenitor cell transplantation or as part of the conditioning regimen. Three patients (two AML, one ALL) received single agent decitabine 1000 mg/m2 total dose) for treatment of relapse post-transplant (group 1). Median age was 32 years. Median time to relapse was 7 months. In another study four patients (three CML in an accelerated phase, one AMML) received decitabine 400 mg/m2, with busulfan 12 mg/kg and cyclophosphamide 100 mg/kg as conditioning for allogeneic stem cell transplantation (group 2). Median age was 42 years; median time to transplant was 5 months. All patients received at least 4 x 10(6) CD34+ cells from their HLA compatible donors. All patients in group 1 achieved complete remissions after decitabine therapy. The median time to neutrophil and platelet recovery were 24 and 23 days, respectively. Two patients required reinfusion of donor cells because of delayed engraftment. One patient remains alive and in remission 160 days post-decitabine therapy. Two patients in group 2 engrafted on days 23 and 25. Two patients required reinfusion of stem cells because of lack of neutrophil recovery by day 21. Two patients achieved complete cytogenetic and hematologic remission. Three patients are alive at 167,129, and 109 days post-transplant. One patient died of progressive Pseudomonas cellulitis 54 days post-initial infusion. Decitabine therapy is well tolerated in the setting of allogeneic stem cell transplantation, initial results in patients relapsing after transplant are encouraging and warrant further studies. The causes of delayed engraftment after single agent or combination therapy need to be better explored. The existence of active metabolites of decitabine which may still be present in the blood at the time of stem cell infusions, and/or insufficient immunosuppression of the preparative regimen are being explored as possible explanations for this phenomenon.

Adult↗
PubMed1997

Tallimustine, an effective antileukemic agent in a severe combined immunodeficient mouse model of adult myelogenous leukemia, induces remissions in a phase I study.

Despite progress in leukemia therapy, only 20-30% of patients with acute myelogenous leukemia (AML) are cured. 1-beta-D-arabinofuranosylcytosine- and topoisomerase II-reactive drugs are the primary therapeutic agents used. The aim of this study was to evaluate the potential activity of tallimustine in leukemia. In this study, we first investigated the efficacy and toxic effects of tallimustine, a distamycin-A derivative, in a human leukemia model in severe combined immunodeficient (SCID) mice. On the basis of its dramatic activity in this preclinical study, a Phase I study of tallimustine at a starting dose of 300 microgram/m2/day for 3 days every 3-4 weeks was conducted in patients with refractory or relapsed leukemia. In SCID mice grafted with a human myelomonocytic leukemia cell line, tallimustine resulted in complete remission of disease in most mice at tolerable dosages ranging from 0.86 to 3.0 mg/kg/day for 3 days and was combined effectively and safely with a 2-day schedule of high-dose ara-C. In the Phase I study, 26 patients with refractory or relapsed leukemia were treated. The maximum tolerated dose was 900 microgram/m2/day for 3 days every 3-4 weeks. This dose was 3 times higher than the maximum tolerated dose in solid tumors and was limited by severe mucositis. Magnesium and potassium wasting were also observed, but other side effects (fatigue and gastrointestinal) were minor. Two (8%) patients with AML achieved complete remission and two achieved hematological improvement with persistent thrombocytopenia. The results of this study indicate that tallimustine has promising activity in AML. Future studies may combine tallimustine with other agents known to be active against AML, and investigate its activity in other hematological malignancies. The recommended Phase II single-agent dose of tallimustine is 750-900 microgram/m2/day for 3 days, and combination studies may start at 50-66% of this dose schedule. The SCID mouse model of human leukemia may be promising in the preclinical evaluation and selection of potential antileukemic agents.

Adolescent↗
PubMed1996

A study of the factors in hip replacement dislocation. Part 2.

Dislocation is a dramatic and distressing common complication following total hip replacement. The first article describing this study, published last week, considered some of the factors thought to predispose to dislocation. The authors emphasised the multifactorial nature of hip replacement dislocation and in this second article they examine the factors relating to acetabular position and orientation, and femoral component placement.

Causality↗
PubMed1996

A study of the factors in hip replacement dislocation. Part 1.

This is the first of two articles which describe a clinical and radiographic review of the reasons for dislocation in patients who have received customised total hip replacements. The researchers compared the alignment of 19 arthroplasties which had dislocated with 347 which had not. A number of factors were considered including pre- and post-operative factors, femoral component placement, component head size, and acetabular position and orientation. It was found the the femoral head size had the greatest influence on dislocation. However, the researchers point out that dislocation on these patients is a multifactoral problem and that prevention, through effective pre-operative and post-operative patient education in relation to care of the hip and mobilising, should be encouraged. They also advocate a multidisciplinary approach to improve patient outcomes. The second article will appear next week.

Adult↗
PubMed1996

Structure, tissue distribution and genomic organization of the murine RRM-type RNA binding proteins TIA-1 and TIAR.

TIA-1 and TIAR are RNA binding proteins of the RNA recognition motif (RRM)/ribonucleoprotein (RNP) family that have been implicated as effectors of apoptotic cell death. We report the structures of murine TIA-1 and TIAR (mTIA-1 and mTIAR) deduced from cDNA cloning, the mRNA and protein tissue distribution of mTIA-1 and mTIAR, and the exon-intron structures of the mTIA-1 and mTIAR genes. Both mTIA-1 and mTIAR are comprised of three approximately 100 amino acid N-terminal RRM domains and a approximately 90 amino acid C-terminal auxiliary domain. This subfamily of RRM proteins is evolutionarily well conserved; mTIA-1 and mTIAR are 80% similar to each other, and 96 and 99% similar to hTIA-1 and hTIAR, respectively. The overall exon-intron structures of the mTIA-1 and mTIAR genes are also similar to each other, as well as to the human TIA-1 gene structure. While Northern blot analysis reveals that mTIA-1 and mTIAR mRNAs have a broad tissue distribution, mTIA-1 and mTIAR proteins are predominantly expressed in brain, testis and spleen. At least two isoforms of both mTIA-1 and mTIAR are generated by alternative splicing. Murine TIA-1 isoforms including or lacking the exon 5 encoded sequences are expressed at a ratio of approximately 1:1, whereas mTIAR isoforms including or lacking the 5'-end of exon 3 sequences are expressed in a approximately 1:6 ratio. Molecular characterization of murine TIA-1 and TIAR RNA binding proteins provides the basis for a genetic analysis of the functional roles of these proteins during mammalian development.

Amino Acid Sequence↗
PubMed1996

Topotecan, a topoisomerase I inhibitor, is active in the treatment of myelodysplastic syndrome and chronic myelomonocytic leukemia.

The aim of this study was to evaluate the activity of topotecan in patients with myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML). Forty-seven patients with a diagnosis of MDS (n = 22) or CMML (n = 25) were treated. The median age was 66 years. Chromosomal abnormalities were present in 70% and thrombocytopenia less than 50 x 10(3)/microL in 51%. Evaluation of outcome and of differences among subgroups was performed according to standard methods; the criteria for response were those used for acute leukemia. Topotecan was administered as 2 mg/ m2 by continuous infusion over 24 hours daily for 5 days (10 mg/m2 per course) every 3 to 4 weeks until remission, then once every month for a maximum of 12 courses. Thirteen patients (28%) achieved a complete response (CR) and six (13%) had hematologic improvement. A CR was achieved in six of 22 patients with MDS (27%) and in seven of 25 with CMML (28%). All eight patients who presented with cytogenetic abnormalities (five chromosome 5 or 7 abnormalities) who achieved CR were cytogenetically normal in CR. Characteristics for which there was evidence of association with a higher response rate were lack of prior chemotherapy, less than 10% marrow monocytes, and absence of RAS oncogene mutations. In contrast, CR rates were similar in patients with or without abnormal karyotypes. Mucositis occurred in 64% of patients (severe in 19%) and diarrhea in 32% (severe in 13%). Febrile episodes occurred in 85% of patients and documented infections in 47%. With a median follow-up duration of 8 months, the 12-month survival rate was 38%, median survival time 10.5 months, and median remission duration 7.5 months. We conclude that topotecan has significant activity in MDS and CMML, with acceptable side effects. Future studies will investigate topotecan combined with topoisomerase II reactive agents, cytarabine, or hypomethylating agents (azacytidine and decitabine).

Adult↗
PubMed1996

The multidomain protein Trio binds the LAR transmembrane tyrosine phosphatase, contains a protein kinase domain, and has separate rac-specific and rho-specific guanine nucleotide exchange factor domains.

rho-like GTP binding proteins play an essential role in regulating cell growth and actin polymerization. These molecular switches are positively regulated by guanine nucleotide exchange factors (GEFs) that promote the exchange of GDP for GTP. Using the interaction-trap assay to identify candidate proteins that bind the cytoplasmic region of the LAR transmembrane protein tyrosine phosphatase (PT-Pase), we isolated a cDNA encoding a 2861-amino acid protein termed Trio that contains three enzyme domains: two functional GEF domains and a protein serine/threonine kinase (PSK) domain. One of the Trio GEF domains (Trio GEF-D1) has rac-specific GEF activity, while the other Trio GEF domain (Trio GEF-D2) has rho-specific activity. The C-terminal PSK domain is adjacent to an Ig-like domain and is most similar to calcium/calmodulin-dependent kinases, such as smooth muscle myosin light chain kinase which similarly contains associated Ig-like domains. Near the N terminus, Trio has four spectrin-like repeats that may play a role in intracellular targeting. Northern blot analysis indicates that Trio has a broad tissue distribution. Trio appears to be phosphorylated only on serine residues, suggesting that Trio is not a LAR substrate, but rather that it forms a complex with LAR. As the LAR PTPase localizes to the ends of focal adhesions, we propose that LAR and the Trio GEF/PSK may orchestrate cell-matrix and cytoskeletal rearrangements necessary for cell migration.

Amino Acid Sequence↗