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Biomedical subjects

R Cahill

Publications and source records attributed to R Cahill.

At least 19 recordsLinked to original sources
PubMed2005

Transanal endoscopic microsurgical repair of iatrogenic recto-urethral fistula.

BACKGROUND: Recto-urethral fistula formation following radical prostatectomy is an uncommon but potentially devastating event. Traditional surgery for such fistulae is technically demanding, jeopardizes continence and usually necessitates a diverting colostomy. We present the case of an iatrogenic fistula treated by a transanal endoscopic microsurgical approach, without recourse to a stoma. METHOD: A 71-year-old man had recently undergone a radical prostatectomy, complicated by significant intra-operative haemorrhage. He subsequently developed a recto-urethral fistula, confirmed clinically and endoscopically. Due to his bleeding diathesis, he was considered for, and underwent, a transanal endoscopic microsurgical (TEMS) repair. CONCLUSION: TEMS is a safe and reliable minimally-invasive surgical technique for the treatment of this difficult condition.

Aged↗
PubMed2000

Induction of lymphocyte recruitment in the absence of a detectable immune response.

Lymphocyte recruitment from blood into the lymph node is thought to be initiated by the presence of antigen. In this study, we have used lymphatic cannulation in sheep to demonstrate that the adjuvant ISCOMATRIX can induce dramatic lymph node activation in the absence of antigen. Consistent patterns of node shutdown (decreased output) and cell recruitment (increased output) with minimal blast cell responses were observed indicating that an antigen-specific immune response is not required. Production of IL-6, IL-8 and IFN-gamma, and the transient presence of red blood cells and neutrophils in the efferent lymph were associated with changes in efferent lymph cell trafficking. These early events may facilitate the screening of low frequency antigen-specific cells for binding to antigen and the subsequent amplification of the immune response.

Adjuvants, Immunologic↗
PubMed2000

Hydroxychloroquine for the treatment of chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) is a major complication of allogeneic bone marrow transplantation. Both the disease and the medications used to treat it are associated with significant morbidity and mortality. The manifestations of chronic GVHD often resemble those of autoimmune disorders. Hydroxychloroquine (HCQ) is a 4-aminoquinoline antimalarial drug used for the treatment of autoimmune diseases. HCQ interferes with antigen processing and presentation, cytokine production, and cytotoxicity and is synergistic with cyclosporine and tacrolimus in vitro. Forty patients with steroid-resistant or steroid-dependent chronic GVHD were enrolled in a phase 2 trial of HCQ 800 mg (12 mg/kg) per day. Three complete responses and 14 partial responses were seen in 32 evaluable patients (53% response rate). All responders tolerated a >50% reduction in their steroid dose while receiving HCQ. Clinical response occurred at a median of 8 weeks (range, 4 to 24 weeks). No hematologic, hepatic, renal, or retinal toxicity was associated with HCQ. In light of its mechanisms of action, clinical activity for GVHD, and low toxicity profile, HCQ may be useful in a multiagent approach for the treatment of extensive chronic GVHD.

Adolescent↗
PubMed1998

Spontaneous inflammatory bowel disease in multiple mutant mouse lines: association with colonization by Helicobacter hepaticus.

BACKGROUND: Both genetic and microbial factors are thought to play a role in the development of inflammatory bowel disease (IBD): however, no causative microbial agent has been clearly defined for humans or animals. Normal flora or previously unrecognized intestinal pathogens may contribute to the development of disease in susceptible hosts. A newly recognized murine Helicobacter, H. hepaticus, causes hepatitis in mice and in one strain of mice is linked to liver cancer. This study investigates the association between colonization of the lower intestinal tract of multiple genetically altered lines of mice with H. hepaticus, and the occurrence of IBD. MATERIALS AND METHODS: Rectal prolapse noted clinically in multiple genetically altered mouse lines was evaluated for the presence of H. hepaticus and histologic evidence of IBD. Fifty-five mice representing 11 different genetic alterations were evaluated. RESULTS: H. hepaticus was detected in 85% of mutant mice with rectal prolapse. Histologic evidence of proliferative typhlitis, colitis or proctitis was present in 65% of the animals examined, 89% of which were positive for H. hepaticus as detected by species specific PCR. CONCLUSION: The presence of H. hepaticus in association with IBD in multiple lines of genetically altered mice suggests further studies are needed to test experimentally the role H. hepaticus plays in the development of IBD in susceptible mice. Additionally, specific mutant mouse lines infected with H. hepaticus in this study may provide additional models for elucidation of microbial and genetic factors in the pathogenesis of IBD.

Animals↗
PubMed1997

Interleukin-2-activated hematopoietic stem cell transplantation for breast cancer: investigation of dose level with clinical correlates.

Incubating hematopoietic stem cells with IL-2 in vitro for 24 h generates cytotoxic T cells. When infused into patients, these cells may stimulate a graft-versus-tumor (GVT) effect. This clinical trial was designed to assess the ability of IL-2 activated peripheral blood stem cells (PBSC) to reconstitute hematopoiesis, to investigate dose levels and dose-limiting toxicities of IL-2, and to evaluate clinical results and preliminary laboratory effects using a combination of IL-2-activated autologous PBSC followed by IL-2 after transplantation. Sixty-one women with stage II-IV breast cancer were treated. After the administration of carboplatin (200 mg/m2/day for 3 days) and cyclophosphamide (2 g/m2/day for 3 days), patients received autologous PBSC that were cultured in IL-2 for 24 h followed by parenteral administration of IL-2 beginning the day of transplantation. Three escalating doses of IL-2 were evaluated with increasing duration up to 4 weeks. Of the 57 patients receiving IL-2 after tranplantation, 19 patients (33.3%) were unable to complete the planned course of IL-2 therapy due to persistent fevers (n = 9), diarrhea (n = 2), pulmonary capillary leak syndrome (n = 3), development of a rash (n = 1), atrial fibrillation (n = 1), or patient's request (n = 3). One death occurred during hospitalization. Engraftment of neutrophils occurred on day 11.5 (mean; range 8-21 days) and platelets on day 11.7 (mean; range 7-33 days). The maximal tolerated dose of IL-2 was 6 x 10(5) IU/m2/day for 4 weeks. Disease-free survival rates for all stages were comparable to current reports in the literature. Preliminary laboratory evaluations include FACScan analysis of the IL-2 activated PBSC demonstrating an increased percentage of CD3+, CD25+, HLA-DR+ T cells. Phenotypically similar cells were present in peripheral blood samples of patients when tested 15 days after transplantation. This study demonstrates successful engraftment with IL-2-activated PBSC after high-dose chemotherapy for women with stage II-IV breast cancer. The regimen is feasible and, although toxicities are common, they are manageable and correlate with increasing dose and duration of IL-2.

Adult↗
PubMed1997

A pilot study evaluating interleukin-2-activated hematopoietic stem cell transplantation for hematologic malignancies.

Cytotoxic effector cells are generated when autologous hematopoietic cells (HSC) are cultured with IL-2 for 24 h. Infusion of these cells followed by IL-2 administration may moderate a graft-versus tumor (GvT) effect in vivo. Sixteen patients--7 with non-Hodgkin's lymphoma (NHL), 2 with AML, 4 with multiple myeloma (MM), and 3 with Hodgkin's disease (HD)--received busulfan (4 mg/kg/day for 4 days) and cyclophosphamide (60 mg/kg/day for 2 days) or cyclophosphamide/TBI (1320 cGy). Autologous HSC were activated by culturing with IL-2 for 24 h before reinfusion. Subcutaneous administration of IL-2 began after engraftment at 1.8 x 10(6) IU/m2/day for 1-4 weeks. Neutrophil engraftment occurred on day 13.1 (median) (range 9-45 days), and platelet engraftment occurred on day 19.3 (median) (range 7-54 days) for 15 patients, with delayed engraftment observed in 3 patients. One patient experienced a fatal cardiac arrhythmia. Five patients developed transient skin rashes with histologic evaluation demonstrating findings consistent with GvHD. At 17 months (median) (range 7-23 months), 9 patients are alive, with 6 patients remaining disease free. This pilot trial demonstrates mild to moderate toxicities and a possible delay in platelet engraftment. Further trials will determine the optimal dose and duration of IL-2 therapy and possible impact of this therapy on survival. Laboratory investigations are evaluating the presence of autologous GvHD and a possible GvT effect.

Adolescent↗
PubMed1996

Stem cell transplantation with chemoradiotherapy myeloablation and interleukin-2.

Interleukin 2 (IL-2) stimulates the proliferation of T-cells both in vitro and in vivo. When murine or human peripheral blood (PB) or bone marrow (BM) mononuclear cells are incubated with IL-2 in vitro for 24 hours, cytotoxic T-cells are generated. If these activated cells are infused into mice, the enhanced cytotoxicity continues if low dose IL-2 is administered. This combination of administering activated cells with the subsequent low dose IL-2 infusion results in enhanced tumor cell destruction and improved survival rates in mice with acute myeloid leukemia. The encouraging results of these laboratory experiments prompted the initiation of phase I clinical trials in patients with refractory/relapsed hematologic malignancies and patients with breast cancer (Stages II-IV). Results from these trials demonstrate that stem cell transplantation with IL-2 activated stem cells (either PB or BM) with or without parenteral administration of IL-2 results in hematopoietic reconstitution with mild-to-moderate toxicities. This regimen also generates cutaneous and visceral autologous graft versus host disease (AuGVHD). The majority of our patients with relapsed/refractory hematologic malignancies or breast cancer developed either clinical and/or histological evidence of AuGVHD. Further studies are being conducted to determine if patients who develop AuGVHD experience improved disease-free survival from a possible autologous graft versus tumor (GVT) effect. Current laboratory evaluations include the elucidation of the pathogenesis of AuGVHD and molecular evaluation of the purging efficacy of IL-2.

Animals↗
PubMed1995

Phase I-II trial of high-dose cyclophosphamide, carboplatin and autologous bone marrow or peripheral blood stem cell rescue.

In an effort to evaluate the toxicities and anti-tumor efficacy of the combination of high-dose cyclophosphamide (CY) and carboplatin, we undertook a phase I-II trial with autologous bone marrow (BM) or peripheral blood stem cell (PBSC) rescue for patients with solid tumors. Forty three patients, 39 of whom had either high risk stage II or III or metastatic breast cancer were treated with escalating doses of carboplatin 1200-1800 mg/m2 and cyclophosphamide 4800-6000 mg/m2 over 3 days followed by autologous BM or PBSC infusion. No life-threatening or fatal toxicities were observed. Reversible congestive heart failure was seen in two patients. Transient hepatotoxicity, characterized primarily by elevation of transaminase levels, and nausea and vomiting, adequately managed with anti-emetic therapy, were seen in 39 and 40 of 43 patients, respectively. The 14 month post-transplant probability of relapse-free survival for 26 patients with high risk II-III breast cancer was 79%; for 13 patients with metastatic disease, the 22 month relapse-free survival probability was 23%. High-dose carboplatin and CY at maximally administered doses of 1800 mg/m2 and 6000 mg/m2 is a well tolerated preparative transplant regimen for autologous BM or PBSC transplantation. It appears to have similar anti-tumor activity and an improved safety profile when compared with other commonly employed transplant preparative regimens.

Adult↗
PubMed1994

Etoposide in combination with cyclophosphamide and total body irradiation or busulfan as conditioning for marrow transplantation in adults and children.

PURPOSE: In an attempt to intensify conditioning therapy for bone marrow transplantation of hematologic malignancies, a retrospective three center evaluation of escalating doses of etoposide added to cyclophosphamide and either total body irradiation or busulfan was undertaken. METHODS AND MATERIALS: Seventy-six patients who received etoposide (25-65 mg/kg) added to cyclophosphamide (60-120 mg/kg) and either total body irradiation (12.0-13.2 Gy) or busulfan (12-16 mg/kg) were evaluable for toxicity. Fifty-one of the evaluable patients received allogeneic transplants, while twenty-six received autologous transplants. A comparative analysis of toxicities according to conditioning regimen, donor source and etoposide dose was made. RESULTS: Similar toxicities were observed among the treatment groups with the exception of more frequent skin (p = 0.003) and life threatening hepatic toxicities (p = 0.01) in the busulfan treated patients. Life threatening or fatal toxicities were not influenced by donor source, either when analyzed by treatment group or etoposide dose. Etoposide at a dose of 60-65 mg/kg in combination with TBI and cyclophosphamide was associated with a significantly increased incidence of life threatening or fatal toxicities compared with a combination using a dose of 25-50 mg/kg (15 of 24 vs. 5 of 20; p = 0.013). The maximally tolerated dose of etoposide in combination with busulfan and cyclophosphamide cannot be definitively established in this analysis in part due to the heterogeneity of the patient population and treatment schemes. CONCLUSION: Although toxicities with bone marrow transplant preparative regimens containing etoposide in combination with cyclophosphamide and total body irradiation or busulfan were frequently severe, treatment related mortality risk was believed to be acceptably low.

Adolescent↗
PubMed1991

Some but not all benefits of intravenous immunoglobulin therapy after marrow transplantation appear to correlate with IgG trough levels.

Multiple benefits of intravenous immunoglobulin (IVIG) therapy after marrow transplantation have been reported, including decreased incidence of acute graft-versus-host disease (GVHD), infection, sepsis, cytomegalovirus (CMV) pneumonitis and platelet use. To test the hypothesis that the observed beneficial effects of IVIG are related to the serum IgG levels achieved, we followed IgG levels (pre-infusion, 1 h and 24 h post-infusion) in 45 consecutive marrow transplant recipients. IVIG 500 mg/kg was given weekly for six doses starting day -8 pre-transplant, then every other week for a total of 11 doses. Forty-one patients (22 allogeneic, 17 autologous, two syngeneic) were evaluable. Patients with acute GVHD had significantly lower serum IgG trough levels (less than 1200 mg/dl) noted at day +20 post-transplant and afterwards than patients without GVHD (greater than or equal to 1200 mg/dl). Pharmacokinetic modeling of the data indicates that IgG half-life between day -8 and day +6 may predict which recipients are at increased risk of acute GVHD. Allogeneic recipients in the group with trough levels less than 1200 mg/dl required more platelet transfusions. Although there was no significant difference in fungal infection rates or bacteremia, sepsis was noted in only two recipients (one allogeneic, one autologous), both with serum IgG trough levels less than 1200 mg/dl. In addition, three allogeneic recipients had cytomegalovirus pneumonitis, all in the group with lower IgG trough levels. Thus, while serum IgG trough levels less than 1200 mg/dl appear to be strongly associated with acute GVHD, low levels may also be associated with increased platelet utilization, with cytomegalovirus pneumonitis, and sepsis, but not with the overall incidence of infection.

Adolescent↗
PubMed1991

Conditioning-related toxicity and acute graft-versus-host disease in patients given methotrexate/cyclosporine prophylaxis.

Intensive chemoradiotherapy conditioning regimens and acute graft-versus-host disease (GVHD) are both associated with significant morbidity and mortality after bone marrow transplantation. In this study, we investigated whether the conditioning regimen affected the development of acute GVHD. Thirty-four patients, four with severe aplastic anemia and 30 with a lymphohemopoietic malignancy, were prepared for transplantation either with cyclophosphamide (CY) alone, with CY combined with total body irradiation (TBI) or CY combined with etoposide and either TBI or busulfan. GVHD prophylaxis included methotrexate (MTX 10 mg/m2) given on days 1, 3 and 6, and daily cyclosporine (CSP) on days--1 through 180. The overall incidence of acute GVHD was 36% (15% for HLA identical, 87% for HLA non-identical recipients). However, when assessed by the severity of conditioning regimen-related toxicity, the incidence of GVHD grades II-IV (HLA identical; HLA non-identical) was 0% (0%; 0%), 37% (20%; 67%) and 50% (22%; 100%) for patients with mild, moderate and severe toxicity, respectively. Compliance with GVHD prophylaxis declined with increasing intensity and toxicity of the conditioning regimen. These data suggest that a regimen of three doses of MTX and daily CSP is as effective as four doses of MTX/CSP for GVHD prophylaxis in patients given HLA identical marrow grafts. However, GVHD regimen compliance and efficacy of GVHD prevention are inversely related to the intensity of the conditioning regimen.

Acute Disease↗
PubMed1990

Transfusion-induced graft-versus-host disease in patients with malignant lymphoma. A case report and review of the literature.

A case of transfusion-induced graft-versus-host disease (GVHD) occurring in a 31-year-old female with Hodgkin's disease in complete remission is reported. Clinical features are similar to 19 other reported cases of transfusion-induced GVHD associated with malignant lymphoma. The lack of relationship with underlying histology or disease stage and the nearly uniformly fatal outcome underscores the importance of prophylactic irradiation of blood products given to patients with malignant lymphoma undergoing therapy.

Adult↗
PubMed1989

Variables affecting specialty choice in occupational therapy.

Over the past 15 years, the number of occupational therapists entering the practice area of mental health has greatly declined. To determine the possible reasons for this decline, a random sample of 450 occupational therapy students who graduated in 1986 was surveyed to identify those factors that influence practice choice. Participants were asked to indicate their practice preferences at five points in time: before admission to the academic program, after completion of the academic program, after completion of Level I fieldwork, after completion of Level II fieldwork, and at first employment. The results from 212 questionnaires (a 47% response rate) indicated that the distribution of practice choices remained relatively consistent over time. After completion of the academic program, the choice of mental health practice was seen as negative. Specific negative influences were topic content, teaching methods, and teacher effectiveness. Level I fieldwork was perceived as a negative experience in all five practice areas, but was perceived most negatively in mental health. Level II fieldwork most influenced practice preferences. Specific positive factors were the student supervisor and the patient caseload.

Career Choice↗
PubMed1989

Escalating doses of etoposide with cyclophosphamide and fractionated total body irradiation or busulfan as conditioning for bone marrow transplantation.

In a phase I study 28 patients with lymphohematopoietic malignancies were treated with escalating doses of etoposide combined with cyclophosphamide 120 mg/kg and either fractionated total body irradiation (TBI) 1320 cGy in 11 fractions (n = 17) or busulfan 16 mg/kg (n = 11). Twenty transplants were allogeneic, seven autologous and one syngeneic. The maximally tolerated dose of etoposide in combination with TBI and cyclophosphamide was 60 mg/kg; at etoposide doses of 65 mg/kg three patients developed life-threatening or fatal mucosal toxicity. In combination with busulfan, the maximally tolerated dose of etoposide was 30 mg/kg. At an etoposide dose of 40 mg/kg two patients developed life-threatening or fatal toxicity (one mucosal, one hepatic). Mucositis requiring narcotic analgesics, hepatotoxicity, hematologic toxicity and interstitial pneumonitis were otherwise similar in TBI and busulfan-treated patients. Skin toxicity was observed significantly more often in the busulfan group. Five deaths occurred before day +30, two in the TBI group and three in the busulfan group. Eleven patients are surviving, ten in continuous complete remission, at a median of 9 (range 3-23) months following transplantation. Etoposide in combination with TBI and cyclophosphamide or busulfan and cyclophosphamide is associated with significant but acceptable toxicities. The maximally tolerated dose of etoposide is higher when combined with TBI than with busulfan. Promising response rates in this high risk group of hematologic malignancies warrant further evaluation of these etoposide containing conditioning regimens.

Adolescent↗