The development and validation of the Pre-operative Intrusive Thoughts Inventory (PITI).

Pre-operative anxiety is common and influences postoperative pain, hospital stay and patient satisfaction. We set out to explore anxiety content and develop a tool to evaluate patient anxiety at the pre-operative assessment clinic. We recruited 128 day surgery patients. Pre-operative anxiety content was explored and six factors (themes) were identified: 'preoccupation', 'outcome concerns', 'being unconscious', 'loss of control', 'dependence on others' and 'pain/discomfort'. The Pre-operative Intrusive Thoughts Inventory (PITI) was constructed and evaluated using exploratory and confirmatory factor analysis. The PITI demonstrated internal consistency for the full scale (Cronbach's alpha = 0.91) and for the subscales (Cronbach's alpha 0.74-0.85) as well as sensitivity (0.88) and specificity (0.60) to clinically significant anxiety assessed using the Hospital Anxiety and Depression Scale. The properties of the PITI suggest that it has potential as an additional tool for the evaluation of pre-operative anxiety.

Protein precipitation by acetone for the analysis of polyethylene glycol in intestinal perfusion fluid.

Canine ileal segments were luminally perfused with known amounts of polyethylene glycol (PEG), and samples obtained were freed of protein by a cold acetone (CA) method and assayed for PEG by trichloroacetic acid in the presence of calcium cations. This procedure was compared to the Barium salt (BaS) protein precipitation method of Hyden (Ann R Agric Coll Sweden 22:411-424, 1955). The CA method saved specimen volume and time in handling, whereas its stability, linearity, and reproducibility were equivalent to the more complex BaS method. In vitro studies disclosed no appreciable differences when PEG specimens were bile stained or dissolved in various solvents. A small modification of the CA method improved accuracy in measurement of small PEG concentrations.

Clindamycin and gentamicin in surgical infections.

The combination of clindamycin phosphate and gentamicin sulfate in treating 53 patients with a variety of serious infections was studied. Initial cultures of specimens from 31 patients yielded both anaerobic and aerobic pathogens. Eleven cultures showed only anaerobic organisms and 11 showed only aerobes. Of patients treated with clindamycin and gentamicin and surgical intervention, 87.8% had bacteriologic cure. Clinical response was poor in only two cases. Two patients developed rash and one had diarrhea, but no reactions suggestive of pseudomembranous colitis were seen.

Isolation and characterization of a lysogenic strain of Nocardia erythropolis.

A stable phage-carrying strain of Nocardia erythropolis was isolated from an infection with the nocardiophage phiEC. Growth of the strain in phage-specific antiserum for 48 hr produced cured organisms at a frequency of about 0.5%. Spontaneous curing, determined by serial single-colony isolations, was less than 0.4%. The strain could not be infected by phage phiEC nor by a closely related phage, phiC, although the cells were able to adsorb these phages. In cell populations, a frequency of 2.5 x 10(-4) cells spontaneously induced. The growth rate of the strain was comparable to that of the uninfected wild-type N. erythropolis. Ultraviolet irradiation or treatment with mitomycin C induced the strain to produce larger numbers of phage. It was concluded that the isolated strain was lysogenic.

Inactivation of nocardiophages phi C and phi EC by extracts of bacteriophage-attachable cells.

Cultures of several species of Nocardia, including N. erythropolis Mat-Ce and Mat-cE mating strains, were extracted with solvents in an attempt to isolate an inactivating complex for nocardiophages phiC and phiEC. Ethanol was the only solvent found effective in solubilizing an inhibitory substance. Inactivating extracts were obtained from the cells of all species to which the phage were able to attach. After extraction of whole cells or cell wall preparations, the phage could not effectively attach to them. Both phages phiC and phiEC were inactivated by the same complex. However, phage phiEC inactivation was 10-fold greater than phiC inactivation. The velocity of inactivation was about 4.1 x 10(2) plaque-forming units per microgram per minute for phiC and 1.1 x 10(3) plaque-forming units per microgram per minute for phage phiEC. The cell extracts required divalent cations for phage inactivation. The inhibitory capacity of the cell extracts was reduced or lost by the activity of proteolytic enzymes, Tween 80, 2-mercaptoethanol, thymol, and sodium lauryl sulfate. Boiling the extract for 10 min did not alter its activity. The inactivating substance was postulated to be a lipoprotein of considerable complexity, unique in the ease with which it is solubilized from host cells by ethanol.