Biofeedback and instructions in the modification of total respiratory resistance: An experimental study of asthmatic and non-asthmatic volunteers

The ability of asthmatic and non-asthmatic subjects to exert voluntary control over pulmonary function was assessed in a short-term experimental context. Total respiration resistance (R_¹ was monitored using the forced oscillation technique with a Siemens Siregnost FD5, while peak flow (PF) and forced expiratory volume (FEV₁) were also recorded periodically. Sixteen non-asthmatic and eight asthmatic volunteers attended one introductory and four experimental sessions. Each experimental session consisted of four 3-min trials, during which the participants tried to lower airways resistance, separated by rest periods. The asthmatic subject, and eight of the non-asthmatics, were provided with visual and auditory analogue feedback of R_t throughout each trial in all sessions. The second non-asthmatic group attempted voluntary control without feedback (instruction only) in sessions 1 and 2, and feedback was subsequently introduced for the final two sessions.

Analysis of sessions 1 and 2 indicated that R_t was lower in thenon-asthmatic given feedback compared with those in the instruction condition. During the final two sessions, differences between the two non-asthmatic groups disappeared. Trends also emerged within sessions, since R_t was higher in trials than rests early in sessions, while later this pattern was reversed. The average change between trials 1 and 4 in the last session was 7.1%. These effects were reflected to a limited extent in PF data.

The asthmatic response was more variable. Two members of this group produced consistent decreases in R_t of 15–20% during trials compared with rests, while modifications in the reverse direction were recorded in two others. Patients may therefore have to be carefully selected for this approach to asthma management. The mechanisms responsible for these responses are uncertain.     

Treatment of experimental poly-d-lysine arthritis in rabbits by non-steroidal anti-inflammatory compounds

The effect of five non-steroidal anti-inflammatory compounds on experimental poly-d-lysine arthritis in the rabbit knee joint have been determined. Two non-invasive methods of assessing the inflammation, measurement of swelling and temperature have been used to follow the effect of treatment. The rank order of potency for the reduction of temperature was indomethacin > flurbiprofen > diclofenac sodium > sulindac > fenclofenac. Reduction in joint temperature was shown not to be due to a vasoconstrictor effect. Reduction of swelling was variable and not doserelated. The method described allows the activity of such compounds on experimental articular arthritis to be determined rapidly.     

A computer system for clinical microbiology.

The Department of Clinical Microbiology at St Thomas' Hospital has been producing bacteriological reports on a computer for more than three years and is now producing some 2300 reports per week. The system is operated entirely by laboratory staff without special training, and involves the use of optical mark reader (OMR) forms as worksheets, automatic validation and release of most reports, the use of local terminals, and scrutiny of reports by pathologists using a visual display unit. The OMR worksheet records not only the final result but also most of the tests and observations made on the samples; it is the only working document used by technicians. One specialist clinic submits its laboratory requests on an OMR form, which is subsequently used to record the results. The reports are printed and also filed in the computer to produce analyses for hospital, laboratory, and clinical management.     

The effect of porcine follicular fluid on ovulation, mating and pregnancy in the rat

We have examined the effects of charcoal-treated, > 10,000 MW porcine follicular fluid (PFF retentate) treatment on ovulation, cyclicity, mating and pregnancy in the rat. Rats treated i.p. with PFF retentate twice on the day of metestrus and once on the day of diestrus exhibited a dose-related reduction in the mean number of ova when oviducts were checked on the afternoon of expected estrus. However, oviducts checked on the morning of expected metestrus contained a normal number of ova. To study the effects of PFF retentate on cycliclty, mating and subsequent pregnancy, rats were treated (0.2 ml, i.p.) two, three or four times a day beginning on the day of metestrus until proestrus cytology was exhibited. PFF retentate treatment resulted in a dose-related delay in the appearance of proestrus cytology and a reduction in the number of embryonic implants following cohabitation with males on the night of proestrus. However, PFF retentate had no effect on the number of implants, when given post-coitally. These results show that administration of PFF retentate to female rats delays ovulation, alters the estrous cycle and reduces the mean number of embryonic implants in a dose-related manner.     

IMMUNE REACTIONS IN PATIENTS WITH BLADDER AND PROSTATIC CANCER1

Although there are many reports of cellular immune reactions in bladder and prostatic carcinoma patients, few have demonstrated the presence of humoral reactivity. The use of microtechniques, especially the enzyme-linked immunosorbent assay (ELISA), has made sequential studies possible on patients with early or small tumours. Using this assay, the presence of serum antibodies has been demonstrated in both bladder and prostate patients, the specificities of these reactions being checked against a battery of different tumours and normal tissues. In many of the patients, with low or transient antibody levels, the presence of circulating immune complexes was shown by the Raji cell assay and analysed by double counter-current immunoelectrophoresis (DCIE). The content of these complexes appeared to be either antibody and tumour antigen or antibody and antiimmunoglobulin. In a small series of cryosurgically treated prostatic carcinoma patients, the course of these antibodies was monitored over several weeks, and the fluctuations in antibody levels were related to the presence of these different types of complexes.