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Biomedical subjects

B A Newton

Publications and source records attributed to B A Newton.

15 recordsLinked to original sources
PubMed1987

Prophylactic use of human leukocyte interferon after allogeneic marrow transplantation.

STUDY OBJECTIVE: To determine the efficacy of prophylactic interferon for prevention of cytomegalovirus infection and relapse of leukemia after allogeneic marrow transplantation. DESIGN: Randomized trial with intermittent interferon administration to day 80 after transplantation. SETTING: Marrow transplantation units of a cancer research center. PATIENTS: Consecutive patients with acute lymphocytic leukemia in remission at the time of transplantation. Thirty-nine patients received interferon, and 40 were control patients. INTERVENTIONS: Partially purified human leukocyte interferon given every 3 days beginning after marrow engraftment and continuing to day 80 after transplantation. After initial safety testing, the starting and minimum dose was 6 X 10(4) units/kg of body weight, with dose escalations determined by the circulating neutrophil count. Transplant conditioning and post-transplantation prophylaxis of graft-versus-host disease with methotrexate followed standard procedures. MEASUREMENTS AND MAIN RESULTS: No difference was observed in the probability or severity of cytomegalovirus infection or in the probability or severity of graft-versus-host disease. Relapse of leukemia occurred in 9 interferon recipients and 21 control patients, with a minimum follow-up of 4 years among surviving patients. The probability of relapse among all interferon recipients was 0.36 (95% confidence interval [Cl], 0.56 to 0.17) and among all control patients was 0.74 (95% Cl, 0.91 to 0.58) (p = 0.04 by log-rank test). Among patients who received transplants in first or second remission, the probability of relapse among interferon recipients was 0.19 (95% Cl, 0.37 to 0.02) compared with 0.71 (95% Cl, 0.97 to 0.51) among control patients (p = 0.008 by log-rank test). Survival rates did not differ between interferon recipients and control patients. Transient decreases in leukocyte count and anorexia and nausea occurred among interferon recipients. Six interferon recipients, all of whom had received chemoradiotherapy of the central nervous system before transplantation, developed leukoencephalopathy after transplantation. CONCLUSIONS: These data suggest that interferon given after transplantation reduces the risk for subsequent relapse of leukemia. The effect of longer administration and of administration in patients with other underlying diseases will require additional trials. No effect was observed on cytomegalovirus infection, either because interferon was not initiated until a median of 18 days after transplantation or because of a lesser effect among marrow allograft recipients.

Adolescent↗
PubMed1987

The effect of prophylactic intravenous immune globulin on the incidence of septicemia in marrow transplant recipients.

Ninety-seven patients randomized to receive (45 patients) or not to receive (52 patients) intravenous cytomegalovirus immune globulin before and after allogeneic marrow transplantation were evaluated retrospectively for the occurrence of bacterial and fungal septicemia in the first 100 days post-transplant. In a proportional hazards regression test, infection prevention regimens, immunoglobulin administration, age and occurrence of acute graft-versus-host disease were tested simultaneously for the occurrence of septicemia in the pre- and post-engraftment period. Of these factors, only patients receiving immunoglobulin had significantly fewer episodes of septicemia following engraftment with 11 (26%) patients in the globulin group having 14 episodes compared to 22 (42%) patients in the control group having 27 episodes (p = 0.039). None of the patients experienced complications with the immunoglobulin infusions. These results suggest that the administration of intravenous immunoglobulin may be a practical and effective method to decrease the incidence of septicemia following marrow transplantation.

Bone Marrow Transplantation↗
PubMed1985

Oral acyclovir therapy for mucocutaneous herpes simplex virus infections in immunocompromised marrow transplant recipients.

In a randomized, double-blinded, placebo-controlled trial, we compared the therapeutic effect of oral acyclovir (400 mg five times daily for 10 days) with that of placebo in patients with marrow transplants and culture-proven recurrent mucocutaneous herpes simplex. Twelve patients received acyclovir and nine received placebo. Acyclovir treatment significantly shortened the median duration of viral shedding, new lesion formation, and time to first decrease in pain, resolution of pain, 50% healing, and total healing. These results compared favorably with those previously obtained with intravenous or topical acyclovir preparations. Oral acyclovir is highly effective for the treatment of recurrent mucocutaneous infections caused by herpes simplex virus in immunocompromised patients.

Acyclovir↗
PubMed1983

The effects of vasopressin on positively rewarded responding and on locomotor activity in rats.

It has been suggested that arginine-vasopressin (AVP) enhances cognitive, and especially mnemonic, ability. Most studies have employed shock avoidance paradigms; we report the results of a study in which saline or vasopressin (0, 0.5 or 1 microgram, mcg, per rat, subcutaneous) pre-treated rats learned to press a lever for food reward. AVP was found to have a disruptive effect on aquisition, particularly when the tendency for these rats to produce extreme learning scores was taken into account. Locomotor activity, with and without vasopressin pre-treatment (0, 0.5, 1 or 2 mcg/rat), was also studied. Only the highest dose significantly reduced activity; therefore, the effects of AVP on acquisition are unlikely to have been caused by motor disruption. The results are discussed in terms of an hypothesis which suggests that AVP enhances arousal, hence influencing performance.

Animals↗
PubMed1982

Ethidium bromide: pharmacokinetics and efficacy against trypanosme infections in rabbits and calves.

[14C]ethidium bromide has been used to determine drug levels in tissues and body fluids of rabbits and calves following intramuscular injection. Uninfected and Trypanosoma brucei- or Trypanosoma congolense-infected animals were studied. Blood and tissue fluid level reached a maximum with 1 h and then fell rapidly; after 96 h 80-90% of the radioactivity injected had been excreted, approximately one third in urine and two thirds in faeces. By 1 h after injection of 1 mg [14C]ethidium/kg into a T. congolense-infected calf, 70-80% of the radioactivity in blood was found to be bound to trypanosomes. Doses of 1 or 10 mg/kg were found not to be curative for T congolense or T. brucei infections in rabbits: drug treatment resulted in a period of sub-patent parasitaemia which was always followed by a relapse. Examination of the prophylactic action of ethidium in rabbits showed that the drug extended the pre-patent period following trypanosome inoculation but provided no absolute protection. A period of "apparent' prophylaxis observed after drug treatment of infected rabbits has been correlated with the presence of anti-trypanosome IgG in the serum.

Animals↗