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Biomedical subjects

A Keating

Publications and source records attributed to A Keating.

At least 127 records · Page 7Linked to original sources
PubMed1991

Influence of total body irradiation on infections after autologous bone marrow transplantation.

Infectious complications were analysed in 50 consecutive autologous bone marrow transplant (ABMT) patients treated with high dose etoposide and melphalan, 30 of whom also received total body irradiation (TBI). Fever developed in 44 patients and bacteremia was documented in 13 (26%). Patients given TBI had increased susceptibility to bacteremia; 11 of 30 patients who received TBI had positive blood cultures, in contrast to two of the 20 who did not (p = 0.035). In addition, patients who received TBI had significantly more severe diarrhea (p = 0.037) when compared with those who received chemotherapy alone. Thirty-five patients treated with trimethoprim-sulfamethoxazole prophylaxis had a signficantly lower incidence of gram-negative bacteremia (p = 0.024). However, when those patients who received trimethoprim-sulfamethoxazole until neutrophil recovery were analysed alone, those who were also given TBI still had significantly more bacteremia (p = 0.047). Forty-seven patients with follow-up of more than 12 months are available for analysis of varicella zoster (VZV) infections. Of the 29 patients who received TBI, 11 (38%) developed VZV infections, in contrast to one of 18 patients (6%) treated with chemotherapy alone (p = 0.013). These results suggest that addition of TBI to the intensive therapy regimen for ABMT is associated with significantly more bacteremia and late VZV infections.

Adolescent↗
PubMed1991

GM-CSF therapy for delayed engraftment after autologous bone marrow transplantation.

Based on previous observations that granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes granulocyte recovery following chemotherapy, we evaluated the effect of recombinant human GM-CSF on hematopoietic progenitors and clinical outcome in six patients with delayed engraftment (greater than 55 days) after high-dose therapy and autologous bone marrow transplantation (ABMT). Three patients responded to a 14-day course of GM-CSF (10 micrograms/kg body weight/day) with at least a sevenfold rise in circulating granulocytes and a corresponding increase in granulopoietic activity in the bone marrow. A fourth patient died of infection on the 8th day of GM-CSF therapy with no evidence of response, and the remaining two, one of whom received a lower dose of GM-CSF (5 micrograms/kg/day), did not respond. There was no change in platelet or red cell transfusion requirements in any patient during the treatment. In two of the three responders, the granulocyte counts returned to pretreatment levels by 4 and 7 weeks after stopping the drug, respectively. We observed a marked increase in marrow-derived as well as in circulating granulocyte-macrophage progenitors (granulocyte-macrophage colony-forming units, CFU-GM) by the end of the 14-day course of GM-CSF in the three responders. There was no change in the frequency of circulating or marrow-derived erythroid (erythroid burst-forming units, BFU-E) or multilineage (multilineage colony-forming units, CFU-GEMM) progenitors. The results indicate that GM-CSF therapy in patients with markedly delayed engraftment after ABMT may stimulate granulopoiesis, but the effect is transient in some patients.

Acute Disease↗
PubMed1990

Autotransplants in chronic myelogenous leukaemia: strategies and results.

Autotransplants are increasingly used in chronic myelogenous leukaemia (CML). Most are performed in advanced leukaemia; now, autotransplants in chronic phase are being evaluated. Treatment involves high-dose chemotherapy with or without radiation followed by a transplant of previously cryopreserved stem cells derived from bone marrow or blood. The transplanted bone marrow may be manipulated in vitro to remove CML cells. Results vary. Transplants in advanced CML usually re-establish chronic phase but responses are brief. After transplants in chronic phase some recipients become Philadelphia chromosome negative for a year or more; others remain Ph-chromosome positive. There are insufficient data to show whether these early transplants prolong chronic phase duration or increase survival. The incurability of CML by conventional therapy should encourage further studies of this approach.

Actuarial Analysis↗
PubMed1990

Neutrophilic myelofibrosis presenting as Philadelphia chromosome negative BCR non-rearranged chronic myeloid leukemia.

Chronic myeloid leukemia consists of Philadelphia chromosome positive disease in 90% of cases, and a further 5%, although Philadelphia chromosome negative, exhibit bcr gene rearrangements consistent with the disease. The remaining 5% of cases have a heterogeneous clinical picture with a course unlike that of classical chronic myeloid leukemia, and may belong to different pathologic entities. We report five cases belonging to the latter group, initially identified as Philadelphia chromosome negative, bcr non-rearranged chronic myeloid leukemia, that developed progressive leucocytosis, absolute monocytosis, myelodysplasia, extramedullary hematopoiesis, and had evidence of myelofibrosis. These cases may represent a distinct clinical entity characterized by neutrophilic myelofibrosis, which can be identified prospectively by clinical and pathologic criteria. Standard therapy for treating chronic myeloid leukemia or idiopathic myelofibrosis may not be appropriate for this group.

Adult↗
PubMed1990

Primary yolk sac (endodermal sinus) tumor of the prostate: case report and review of the literature.

A primary yolk sac (endodermal sinus) tumor of the prostate is described in a 40-year-old male. This is the second documented case of a yolk sac tumor occurring in the prostate gland. Treatment included surgical removal and subsequent combination chemotherapy. Four months following diagnosis, the patient died of complications. At autopsy, no residual tumor was detected. The role of combination chemotherapy as potentially curative therapy in the treatment of extragonadal yolk sac tumors is discussed.

Adult↗
PubMed1990

Acute transient parotitis after high dose etoposide and autologous bone marrow transplantation.

Etoposide is an important component of several intensive therapy regimens in allogeneic and autologous bone marrow transplantation for advanced hematologic malignancies. We observed the occurrence of transient acute parotid and submandibular sialoadenitis in nine of 19 patients receiving high dose etoposide and melphalan followed by autologous bone marrow rescue. Manifestations included pain, tenderness and swelling of the parotid and submandibular glands. Symptoms arose 4-16 h after completion of etoposide infusion and resolved within 72 h. Elevation of serum amylase accompanied the symptoms, and was also observed in some patients who were asymptomatic. Discomfort was controlled with analgesics and the clinical course was uncomplicated in all cases. Transient parotitis is a relatively frequent and benign complication of high dose etoposide therapy.

Acute Disease↗
PubMed1990

Chronic myeloid leukemia arising in a progenitor common to T cells and myeloid cells.

Until recently, T cells were believed not to be involved in chronic myeloid leukemia. We describe an example of CML in T lymphoblastic crisis with massive generalized lymphadenopathy in which the blasts were CD2(+), CD5(+), and CD7(+), variably CD1(+) and CD3(+), and both responded to and could be induced to produce the T cell growth factor, interleukin-2. Additionally, the blasts were shown to contain the CML-related tyrosine kinase P210bcr-abl rather than the smaller kinase associated with Ph1(+) ALL. Finally, the participation of the T lymphoid lineage in the CML clone was proven by the presence of the same BCR rearrangement in blasts as in granulocytes, suggesting the existence of a bone marrow progenitor common to the T cell and myeloid lineages.

Adult↗
PubMed1990

Analysis of factors affecting hematopoietic recovery after autologous bone marrow transplantation for lymphoma.

Thirty patients with relapsed lymphoma (14 Hodgkin's disease, 16 non-Hodgkin's lymphoma) who underwent autologous bone marrow transplantation (ABMT) were assessed for the effect of different parameters on the rate of hematologic recovery post-ABMT. There was no correlation between nucleated cells count or numbers of CFU-GM or BFU-E in the infused marrow on either neutrophil or platelet recovery times. Patients with lymphoma who received more salvage chemotherapy (greater than six cycles) prior to marrow harvest took significantly longer to recover neutrophils to greater than 0.5 x 10(9)/l (p = 0.0229) and platelets to greater than 20 x 10(9)/l (p = 0.0007) than patients who received less than five cycles of salvage chemotherapy prior to harvest. There was no significant correlation between underlying disease, use of total body irradiation or status of cytomegalovirus serology and recovery times post-ABMT. The results suggest that extensive salvage chemotherapy may result in considerable stem cell damage to marrow, and that potential ABMT candidates with lymphoma should undergo harvest of tumor-free bone marrow as soon as possible following first relapse.

Adolescent↗
PubMed1990

Gene transfer by electroporation: a model for gene therapy.

We examined electroporation for the introduction of DNA into hematopoietic cells in order to develop an in vitro model for human gene therapy. We demonstrated that electroporation is a relatively efficient and reproducible method of gene transfer in permanent hematopoietic lines. Characterization of DNA transfer revealed that genes are integrated in single or low copy number. We showed that human normal granulopoietic progenitors can express the transferred gene at a frequency of more than two percent. Although the progeny of erythroid progenitors failed to express transferred genes, the frequency of transfer to erythroid clones, as detected by the polymerase chain reaction, was moderately high (16%). In order to improve efficiency of expression, we examined the effect of different viral and cellular promoters in the hematopoietic lines K562 and KG1a as well as in marrow stromal cells. We found that Rous Sarcoma virus LTR was the most active promoter in K562 while the murine cytomegalovirus immediate early promoter was highly active in KG1a and marrow stromal cells. Further improvements in the efficiency of DNA transfer and expression with electroporation are likely to result in a successful hematopoietic model for gene therapy.

Bone Marrow↗
PubMed1990

Evaluation of cytoreductive therapy prior to high dose treatment with autologous bone marrow transplantation in relapsed and refractory Hodgkin's disease.

Based on observations that bulky disease at autologous bone marrow transplantation (ABMT) may be correlated with poor outcome in Hodgkin's disease, we have assessed the ability of conventional-dose chemoradiotherapy to reduce tumour burden to a minimum prior to ABMT. Thirty-seven patients with relapsed or refractory Hodgkin's disease referred for intensive therapy and ABMT were treated initially with one to five cycles of DHAP chemotherapy. All patients had previously received MOPP and ABVD chemotherapy or similar regimens. Four patients achieved complete remission (CR) and 12 partial remission (PR), for a total response rate of 43%. Eight partial responders and four non-responders to DHAP achieved significant further tumour reduction with local radiotherapy (five CR, seven PR). Six of 10 non-responders to DHAP responded to alternative salvage chemotherapy (mini-BEAM, CEP or augmented CVP). Overall, 24/37 patients (65%) achieved effective cytoreduction (nine CR, 15 PR with minimal disease) and have proceeded to ABMT. Patients with bulky disease at relapse or limited stage (II, IIIA) at diagnosis were less likely to respond to DHAP, but some of these could be cytoreduced with alternative therapy. In addition, the number of prior chemotherapy regimens correlated inversely with likelihood of response to DHAP. The results indicate that approximately two-thirds of patients with Hodgkin's disease who relapse after MOPP and ABVD-like regimens can achieve effective cytoreduction with conventional-dose chemoradiotherapy and proceed to ABMT in CR or PR with minimal disease.

Adolescent↗
PubMed1990

Effect of different promoters on expression of genes introduced into hematopoietic and marrow stromal cells by electroporation.

Electroporation is a simple and relatively efficient means of introducing genes into hematopoietic cells. However, achieving and maintaining high levels of gene expression in transfected hematopoietic progenitor cells remains problematic. In order to address this problem we examined the effect of different viral and cellular promoters on the transient expression of reporter genes transferred into K562, KG1a, and human marrow stromal cells. We found that although the Rous sarcoma virus long terminal repeat was most active in K562 cells in a transient expression assay, the murine cytomegalovirus immediate early promoter was strikingly more active than the other promoters in KG1a cells as well as in the marrow stromal cell population. Long-term stable gene expression was also demonstrated in stromal cells. We infer that the murine cytomegalovirus immediate early promoter may be highly active in human hematopoietic progenitor cells and that human marrow stromal cells may be an attractive vehicle for gene delivery.

Bone Marrow↗
PubMed1989

Tissue-specific activity of heterologous viral promoters in primary rat hepatocytes and Hep G2 cells.

In preparation for studies using gene transfer, we have identified transcriptional control elements which are active in primary rat hepatocytes. We used plasmids which were constructed so that the promoter or enhancer of interest initiated transcription of the bacterial chloramphenicol acetyltransferase (CAT) gene. Plasmids were introduced into primary rat hepatocytes in culture, into Hep G2 cells and other human and animal cell lines and into bone marrow stromal cells, and CAT activity was assayed after 48 hr. In primary rat hepatocytes, the highest CAT activity was obtained with plasmids carrying the Rous sarcoma virus long terminal repeat (pRSVCAT), or the SV40 early region promoter and enhancer (pSV2CAT). Hepatocytes carrying the murine cytomegalovirus immediate early promoter (pUCRNmCMVX/HCAT) also had appreciable CAT activity. No CAT activity was detected in rat hepatocytes carrying pSVOCAT (a promoterless construct), pUCRNtKCAT (herpes simplex thymidine kinase gene promoter), pLPVCAT (lymphocytotrophic papovavirus promoter) and pHBV1CAT (hepatitis B virus enhancer and core gene promoter). Therefore, for future studies of gene transfer in primary rat hepatocytes, the Rous sarcoma virus long terminal repeat or the SV40 early region promoter and enhancer can be effectively used to drive gene expression. Hep G2 cells carrying pHBV1CAT had high CAT activity. Hep G2 cells carrying pHBV2CAT (similar to pHBV1CAT, but with the hepatitis B virus sequences in reverse orientation with respect to the CAT sequences) and pHBV3CAT (similar to pHBV2CAT, but hepatitis B virus sequences are separated from the CAT sequences by about 700 bases) also expressed CAT activity, but not as strongly as with pHBV1CAT.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Ketoconazole: a possible direct cytotoxic effect on prostate carcinoma cells.

Ketoconazole has been recently used in the treatment of advanced prostatic cancer and is believed to exert its effect by inhibition of androgen production. In order to determine whether ketoconazole exerts an additional direct cytotoxic effect on prostate cancer cells, we studied its effect on human hormone-independent prostate cancer cell lines (PC-3 and DU-145) in an in vitro clonogenic tumor assay. We showed that clinically achievable doses of ketoconazole caused greater than 90% suppression of tumor colony growth.

Carcinoma↗
PubMed1989

An evaluation of outpatient bone marrow harvesting.

In order to avoid the difficulties in scheduling and cost involved in admitting patients to hospital to undergo bone marrow harvests, we assessed outpatient marrow harvesting for autologous bone marrow transplant (BMT) candidates. Over a 13-month period, 39 consecutive patients with hematologic malignancies underwent bone marrow harvests as outpatients. For comparison we also evaluated 20 consecutive patients with similar disease status who had undergone bone marrow harvests as inpatients over the preceding 6 months. The mean hemoglobin value prior to harvest the mean volume of marrow harvested, and the mean nucleated cell count in the outpatient group were not significantly different from those of the inpatient group. There were no intraoperative complications. Of these 39 patients, 36 were discharged later the same day on oral iron supplements, with no adverse sequelae. Local pain was well controlled at home with mild oral analgesics. Two patients required admission due to postoperative hypotension--both responded promptly to intravenous (IV) fluids and blood and were discharged the following day. One patient was admitted postoperatively due to fever. There was a trend for the outpatients to receive less intra- and postoperative blood transfusions, but this did not reach statistical significance. The results suggest that most candidates for autologous BMT can safely undergo bone marrow harvesting as outpatients, thereby relieving pressure for hospital beds, potentially reducing costs and improving bed utilization. The study also raises the possibility of safely performing outpatient harvests on allogeneic BMT donors.

Adolescent↗