Establishing a programme for continuous ambulatory infusion chemotherapy.

BACKGROUND: The development of venous access devices (VADs) and portable infusion pumps has enabled chemotherapy to be administered continuously within the home environment. AIM: The objective of this study was to describe the experience of establishing an ambulatory chemotherapy programme for patients receiving protracted infusions (PVIs) of 5-fluorouracil (5-FU). METHODS: The files of all patients receiving PVI 5-FU as a component of their treatment for gastrointestinal malignancy were reviewed. The types of VADs, infusion pump systems and their management were documented. Information packages and education programmes were developed for patients. RESULTS: Seventy-four patients with gastrointestinal cancer were studies. At the end of the period the Portacath was the preferred VAD, while both pumps used were found to have advantages and disadvantages. The choice of pump was decided more by patient preference than systematic differences in performance of the pumps. CONCLUSIONS: The findings in this review confirm that, with close attention to the potential pitfalls of ambulatory chemotherapy, an acceptable service can be provided.

Antagonism of Pseudomonas cepacia against phytopathogenic fungi.

Two strains of Pseudomonas cepacia, RJ3 and ATCC 52796, have been identified as potential antagonists of fungal plant pathogens. We have compared the antagonistic activity of these two strains against various fungal pathogens. Although both strains displayed high levels of antagonism, ATCC 52796 was slightly more antagonistic than RJ3. The antagonist from RJ3 has been identified as the antifungal compound pyrrolnitrin after purification by HPLC and characterization by UV, IR, NMR, and mass spectroscopy. Both strains also antagonized the fungi by production of volatile compound(s), which have not yet been identified. Both strains are similar with respect to in vitro antagonism, mechanism of antagonism, and sensitivity to antibiotics.

Transposon Tn5-259 mutagenesis of Pseudomonas cepacia to isolate mutants deficient in antifungal activity.

Transposon Tn5-259 was inserted into the chromosome of Pseudomonas cepacia by mating with an Escherichia coli strain harboring a self-mobilizable, temperature-sensitive plasmid, pME12. Data from Southern blots and auxotroph analyses indicated that a single copy of the transposon was inserted in several places into the chromosome of P. cepacia. Among 1500 Tn5-259 transconjugants, only one mutant was found to be defective in the production of an antifungal compound, pyrrolnitrin. In addition, this mutant lost its ability to antagonize fungal phytopathogens. Using flanking DNA of the mutated gene as a probe, we have isolated four overlapping cosmid clones from a genomic library of P. cepacia. However, we were unable to complement the mutant because of difficulty in mobilizing the cosmids from E. coli to P. cepacia.

Environmental factors affecting the antagonism of Pseudomonas cepacia against Trichoderma viride.

Antagonistic activity of the bacterium Pseudomonas cepacia against Trichoderma viride was greatly influenced by nutritional and environmental conditions. Xylose and trehalose strongly enhanced the antifungal activity of P. cepacia, whereas mannitol and glucose had little effect. The carbon sources that enhanced the antagonistic activity also inhibited sporulation of T. viride. Antagonism of P. cepacia was enhanced by ammonium nitrogen; however, with nitrite or nitrate there was only a little antagonism. The antagonism of P. cepacia was optimal at pH 5.0. Although P. cepacia showed maximum antagonism against T. viride at 37 degrees C, the antagonism was fairly good at temperatures as low as 18 degrees C, indicating that there is a broad range of temperature for the antifungal activity of P. cepacia.

Effects of unloading and positive inotropic interventions on left ventricular function in asymptomatic patients with chronic severe aortic insufficiency.

The effect of an unloading (nifedipine, 20 mg sublingually) and of a combined unloading and positive inotropic intervention (nifedipine plus digoxin, 0.5 mg intravenously) on left ventricular performance was assessed in 48 patients with chronic severe aortic insufficiency. The left ventricular pump function-myocardial contractility relation (ejection fraction, EF vs. peak arterial pressure to end-systolic volume ratio, PAP/ESV), and the pump function-afterload relation (EF vs. mean systolic wall stress, MWS) were constructed by means of quantitative M-mode and two-dimensional echocardiography. In patients with normal control pump function (n = 14), nifedipine markedly decreased MWS, moving the patients to a new, more advantageous EF-MWS relation. In the 34 patients with abnormal pump function, the myocardial contractility level was the mean factor conditioning the response to pharmacological intervention. Patients with a value of PAP/ESV greater than 2.5 (n = 22) had normalization of EF after nifedipine and were upgraded to a more advantageous outlook for left ventricular mechanics EF-MWS and EF-PAP/ESV relations. Of the 12 patients without normalization of EF after nifedipine, only the 4 patients with PAP/ESV greater than 2 had normalization of pump function indices after combined administration of nifedipine and digoxin.

Variability of positive inotropic response to acute amrinone administration in chronic cardiac failure.

To determine the factors conditioning the variability of positive inotropic response after intravenous acute amrinone administration, 14 patients with chronic cardiac failure were studied by quantitative M-mode and cross-sectional echocardiography. Six patients had idiopathic dilated cardiomyopathy and 8 patients had severe chronic aortic insufficiency. Myocardial contractility (evaluated as peak arterial systolic pressure/end-systolic volume ratio: PAP/ESV) did not change in patients with idiopathic cardiomyopathy, a significant increase of myocardial contractility occurred in patients with aortic regurgitation only if the control value of PAP/ESV was greater than 1. Mean systolic wall stress decreased significantly in all patients, independent of aetiology of cardiac failure and was the factor determining the improvement of left ventricular performance (evaluated as fractional shortening) in patients without changes in myocardial contractility. Maximum improvement in left ventricular performance occurred 10 minutes after amrinone administration. It is concluded that the possibility of detecting the positive inotropic properties of amrinone in man depends on the aetiology of the cardiac failure and on the basal level of myocardial contractility.