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Biomedical subjects

M Keating

Publications and source records attributed to M Keating.

197 records · Page 11Linked to original sources
PubMed1984

Piperacillin plus vancomycin in the therapy of febrile episodes in cancer patients.

Piperacillin and vancomycin were used as initial empirical therapy for 211 febrile episodes in cancer patients. The response rate in 95 episodes of documented infection was 72%. The response of bacteremias, soft tissue infections, and pneumonias was 78, 71, and 38%, respectively. The response in infections caused by gram-negative organisms was 73%. Only 6 of 10 Pseudomonas aeruginosa infections responded to therapy, although the organisms were sensitive in vitro to piperacillin. Of 14 infections caused by gram-positive organisms, 12 responded to this combination. No major side effects were observed with this regimen. Although the overall response rate with this antibiotic combination was comparable with other regimens used for neutropenic patients, superior results might be obtained by combining piperacillin with an extended-spectrum cephalosporin or an aminoglycoside.

Bacterial Infections↗
PubMed1984

Oncogene expression in human leukemia.

The transforming genes of retroviruses (v-onc) are derived from normal cellular genes referred to as proto-oncogenes. These cellular genes have the capacity for conversion to oncogenes (c-onc) that are capable of inducing or maintaining the transformed state when they are overly expressed or altered by mutation or rearrangement. To study the possible involvement of these genes in human leukemia, we have analyzed their expression in a variety of fresh samples. We found that a number of oncogenes are expressed in different leukemic types and that although the transcript size did not vary for each gene, the copy number did. The myc gene (2.4 kb transcript) and the rasHa gene (1.5 kb transcript) were universally expressed. But in contrast to rasHa, the myc signal intensity varied. Myb (4.5 kb transcript) was expressed in all samples except B cell diseases. We detected low levels of abl expression (multiple mRNA species) in all leukemic types analyzed. Sis gene (4.2 kb transcript) expression was restricted to one patient sample with chronic myelogenous leukemia in blast transformation.

Acute Disease↗
PubMed1984

Phase I clinical investigation of homoharringtonine.

Homoharringtonine is a cephalotaxine ester derived from Cephalotaxus harringtonia, which is a Chinese evergreen tree. A limited clinical evaluation of this drug in China revealed antileukemic activity, which prompted clinical trials in the United States. We have treated 43 patients with a variety of refractory malignancies using a daily iv treatment for 5 days at 3-4-week intervals. The starting dose of homoharringtonine was 0.2 mg/m2/day and it was escalated to a maximum of 8 mg/m2/day. The dose-limiting toxic effect was hypotension, which was generally mild with daily dose levels of 3-4.5 mg/m2/day and required no specific treatment besides iv fluid supplements in some patients. Hypotension became increasingly severe at the higher dose levels and resulted in cardiovascular collapse in four of 16 patients treated with dose levels of 5-6 mg/m2/day. A moderately severe degree of myelosuppression was observed with homoharringtonine doses of greater than or equal to 3 mg/m2. Myelosuppression was clearly related to the extent of prior treatment and was minimal in patients who had not received extensive prior treatment. Gastrointestinal toxic effects of nausea, vomiting, and diarrhea were observed in approximately two-thirds of the patients but these side effects were generally mild and self-limited. Drug-related fever and alopecia were also observed in some patients. No major responses were observed, although three patients with solid tumors evidenced minor responses and three of five patients with acute leukemia showed some degree of antileukemic activity. For phase II studies of homoharringtonine in solid tumors, a daily dose of 3 mg/m2 for 5 days in patients with extensive prior treatment and 4 mg/m2/day for 5 days in patients with good bone marrow reserve will be utilized. The daily dose must not exceed 4 mg/m2 to avoid serious hypotension; further dose escalations should be accomplished by extending the number of days of treatment beyond 5 days.

Adult↗
PubMed1983

Clinical course and response to treatment of patients with acute myelogenous leukemia presenting with a high leukocyte count.

The natural history and response to treatment of 46 patients with acute myelogenous leukemia and a pretreatment leukocyte count of 100,000/microliters or higher were reviewed to identify the clinical features and response characteristics to the treatment of this group of patients. While the response rate of 52% was similar to that of patients with lower leukocyte counts, remission durations were shorter and related inversely to the height of the initial leukocyte count and to the number of treatment courses necessary to achieve a complete remission. A high incidence of hemorrhagic deaths was observed during the first 8 days of treatment. These hemorrhages occurred at a time when the leukocyte count was falling secondary to chemotherapy and the platelet count was still greater than 15,000/microliters. Pretreatment coagulation disorders and poor performance status were factors associated with this fatal complication. Antimetabolites to rapidly arrest leukemic cell proliferation and leukapheresis to avoid further leukostatic plug formation may be useful immediate measures to reduce the incidence of these fatal hemorrhages until the underlying pathogenic mechanisms have been elucidated.

Adult↗
PubMed1983

Human leukocyte interferon to control thrombocytosis in chronic myelogenous leukemia.

Nine patients with refractory chronic myelogenous leukemia and severe symptomatic thrombocytosis (greater than or equal to 1 X 10(6) platelets/mm3) were given partially purified human leukocyte interferon-alpha. A significant decline in platelet counts, from a mean (+/- SE) of 1.71 +/- 0.53 X 10(6)/mm3 to a mean of 0.52 +/- 0.24 X 10(6)/mm3 (p less than 0.01), resulted in all patients. Maintenance of low platelet counts was achieved in two patients for more than 143 and 300 days, respectively. Treatment with human leukocyte interferon-alpha was stopped in the remaining patients because of increases in the leukocyte count, toxicity, or both. Our preliminary observations suggest that human leukocyte interferon-alpha may significantly alleviate progressive thrombocytosis in advanced chronic myelogenous leukemia. Further studies of human leukocyte interferon-alpha and chemotherapeutic agents are indicated.

Adult↗
PubMed1979

The effectiveness of rubidazone in hairy cell leukemia (leukemic reticuloendotheliosis).

Two patients with hairy cell leukemia treated with the anthracycline antibiotic rubidazone are presented. One achieved a complete remission and the other a good partial hematologic and bone marrow remission. Neither has relapsed (at 20 and 13 mo, respectively), and neither has been retreated. Intensive supportive measures were required during the prolonged myelosuppression that followed treatment. The relative youth of the patients (ages 24 and 39 yr) may have contributed to their ability to survive until normal marrow recovered. Chemotherapy should not be employed in the initial management of hairy cell leukemia. However, if life-threatening granulocytopenia and thrombocytopenia occur secondary to bone marrow replacement by leukemic cells, and improvement does not occur using alternative methods of therapy, consideration could be given to chemotherapy with rubidazone. Facilities for intensive supportive care should be available.

Adult↗
PubMed1978

Autologous bone marrow transplantation in patients with adult acute leukemia in relapse.

Nine patients with adult acute leukemia were treated in relapse with piperazinedione plus supralethal total body irradiation in conjunction with autologous marrow infusion. Bone marrow cells were collected and stored in first remission. Storage time varied from 3 to 23 months. Before storage, marrow cells were separated using density albumin gradients in order to reduce the number of leukemic cells in the graft. Three patients died before day 14 after transplantation because of complications already present at the time of transplantation. In six patients, hemopoietic recovery started to occur within 14 days after transplantation. In four patients leukemia-free periods were obtained, lasting 60+ days. The three patients with the longest leukemia-free period after transplantation (range 75 to 220+ days) are reported in more detail. One patient is still alive without evidence of leukemia, with full hematological recovery 220+ days after transplantation.

Acute Disease↗
PubMed1977

Gram-negative bacillary infections in cancer patients.

The majority of infectious complications in cancer patients are caused by Gram-negative bacilli. The most common organisms are Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa. Sites of infection are related to the patients' underlying malignancies, but pneumonia and septicaemia occur most often. Important newer antibiotics for the therapy of these infections are aminoglycosides and semisynthetic penicillins. It is advisable to utilize combinations of antibiotics for serious infections in cancer patients, and therapy should be instituted promptly at the onset of infection.

Anti-Bacterial Agents↗
PubMedDate not supplied

Statistical profile of traumatic brain injury: a Canadian rehabilitation population.

A retrospective clinical hospital chart study was undertaken to prepare a statistical profile of traumatic brain-injured patients in rehabilitation. It included 498 consecutive admissions to the Traumatic Brain Injury Rehabilitation Program of the Queen Elizabeth Hospital (Toronto, Canada) from 1978 to 1991. Descriptive statistics were obtained for age, gender, marital status, educational status, occupational status, history of drug and alcohol use, cause of injury, month of injury and length of coma. Comparisons are made between the studied population and several Canadian centres, as well as international brain injury demographics in the literature. Results are discussed in terms of the gender differences and lifestyle parameters associated with brain injury.

Adolescent↗
PubMedDate not supplied

Clinical pharmacology of polyethylene glycol-L-asparaginase.

Polyethylene glycol (PEG)-L-asparaginase, at doses ranging from 500 to 8000 units/m2, was infused iv over 60 min in 31 patients of whom 27 were evaluable pharmacokinetically. The plasma disappearance of PEG-L-asparaginase is described by a monophasic curve with a mean half-life of 357 +/- 243 hr which is much longer than that of the unconjugated enzyme (half-life of approximately 20 hr). The rate of total clearance (128 +/- 74 ml/m2 X day) is much slower than that of L-asparaginase (2196 +/- 1098 ml/m2 X day). The volume of distribution is 2093 +/- 643 ml/m2, which is similar to that of L-asparaginase, indicating that PEG-L-asparaginase is mainly localized in the plasma. No enzyme could be measured in urine samples taken from nine patients for a period of up to 4 days. Additionally, no enzyme was measurable in one patient's pleural fluid obtained at the end of infusion and 6 days after infusion of a 1000-unit/m2 dose; the corresponding concentrations in plasma were 0.64 and 0.62 units/ml, respectively. In general, the plasma enzyme concentrations at the end of the 1-hr infusion and at 14 days after drug administration were proportional to the dose given. However, in two patients, a sudden disappearance of enzyme levels occurred which preceded anaphylactic reactions during subsequent treatment. A third patient developed severe bronchospasm 30 min after the first dose, but his enzyme levels were within the normal range.

Adult↗
PubMedDate not supplied

Combination of high-dose cyclophosphamide, BCNU, and VP-16-213 followed by autologous marrow rescue in the treatment of relapsed leukemia.

The combination of high-dose cyclophosphamide, BCNU, and VP-16-213 followed by autologous marrow rescue was evaluated in the treatment of relapsed leukemia refractory to normal-dose chemotherapy. Cyclophosphamide was given at a total dose of 4.5 g/m2, BCNU at a dose of 300 mg/m2, and VP-16-213 at a dose of 600 mg/m2. Seven high-dose treatments followed by marrow rescue were administered to six patients. Two patients achieved complete remissions, three had partial remissions, and one achieved a minimal response. The toxicity of this regimen was moderate.

Acute Disease↗