The use of an isolator system in cancer chemotherapy

Prevention of infection and graft-versus-host disease by suppression of intestinal microflora in children treated with allogeneic bone marrow transplantation

The effect of suppression with antimicrobial agents of the intestinal microflora of paediatric bone marrow graft recipients on severe bacterial and fungal infections and on moderate to severe acute graft-versus-host disease was studied retrospectively. Data on 65 cases of bone marrow transplantation for either severe bone marrow failure or leukaemia, performed in a strict protective environment with either complete or selective gastrointestinal decontamination, were evaluated. All bone marrow grafts were from HLA-identical siblings and were not depleted of T-lymphocytes. Twenty percent of the recipients had one or more episodes of septicaemia during the granulocytopenic period after transplantation, mostly due to gram-positive bacteria. Only five children died due to infection, in each case caused by a microorganism originating from the endogenous flora. Complete gastrointestinal decontamination was superior to selective gastrointestinal decontamination in preventing infectious complications (p less than 0.001). The same was the case for the prevention of acute graft-versus-host disease of grade II or higher, which was observed in 7 of 40 (17.5%) completely decontaminated children versus 9 of 18 (50%) selectively decontaminated children evaluable for graft-versus-host disease (p less than 0.01). It is concluded that complete gastrointestinal decontamination in a strict protective environment is a feasible and very effective method for preventing severe infections and acute graft-versus-host disease after allogeneic bone marrow transplantation in children and adolescents; it resulted in a low transplantation-related mortality of 26% and a good quality of survival in 69% of the graft recipients.

The use of sterile and low microbial diets in ultraisolation environments

The evidence for the use of sterile and low microbial diets in ultraisolation environments is reviewed. Studies have suggested that sterile food is not required for gut sterilization when oral nonabsorbable antibiotics are used, but if a low microbial food contains an antibiotic-resistant organism, colonization can occur. There may be a beneficial effect on the incidence of infection by serving pathogen-free foods, either sterile or low microbial, to the immunosuppressed patient regardless of type of environment, yet the comparative effectiveness of sterile and low microbial diets in preventing introduction of new pathogens accessing the host via the mouth, oropharynx, and esophagus has not been systematically evaluated.

The management of acute myelogenous leukemia

Although definite improvement in the treatment of acute myelogenous leukemia has taken place, the outlook for patients remains grim. The current aggressive approach to treatment, entailing a program of chemotherapy which almost invariably produces bone marrow aplasia and considerable toxicity, has been the subject of some controversy. Selected aspects of management are discussed.

Elimination of bacteria from dogs with antibiotics

The effect of oral administration of neomycin cephalothin or kanamycin cephalothin on the aerobic intestinal bacterial flora, was studied in dogs maintained under isolation conditions in a conventional animal room. The dogs were successfully freed of aerobic bacteria with both combinations within two to seven days after the start of antibiotic treatment, and were maintained bacteria free for up to 21 days. Decontamination was attained more rapidly in dogs that were bathed in hexachlorophene surgical soap before and during the first and third days of antibiotic treatment. There was no evidence of toxicity from either of the antibiotic combinations. These results indicate that, as with mice and monkeys, decontamination of dogs with oral antibiotics is feasible. The technique is of potential value in preventing endogenous bacterial infections in canine experimental studies involving use of immunosuppressive agents.

Pathogen-free isolation unit--three years' experience

The results obtained during the first three years of a pathogen-free isolation unit containing five beds have shown that this type of unit can reduce the risk of infection in patients treated with intensive chemotherapy or in those who have granulocytopenia from various causes. It is suggested that treatment of cancer which involves these risks should be carried out routinely in sterile isolation units, and that it is urgent to build many more and much larger units.