Smoking topography and carbon monoxide levels in smokers.

Factors which effect the expired air carbon monoxide (CO) levels of smokers were examined in matched subject pairs who smoked an equal number of daytime cigarettes but had different CO levels (mean difference = 15.4 ppm). Measures of puff number, duration, and spacing, as well as the amount of CO increase per cigarette (CO boost), were assessed while subjects smoked a single cigarette in daily laboratory sessions. Subjects with relatively high CO levels had larger increases in CO after smoking a single cigarette than did individuals with low CO levels (p. less than .005) but did not differ on any other smoking topography measure. These data suggest that simple topography measures of puff number and duration may not contribute to between subject differences in tobacco smoke exposure, and that greater attention should be given to more refined measures such as puff volume and depth of inhalation. These data also suggest that the measurement of CO boost per cigarette may provide useful information regarding tobacco smoke intake.

The effects of contingent payment and frequent workplace monitoring on smoking abstinence.

This study examined the relative contribution of contingent payment and worksite CO monitoring to the long-term maintenance of smoking abstinence. Forty-seven hospital employees who had abstained from smoking for five days (confirmed by CO analysis) were randomly assigned to one of three follow-up groups: (a) contingent payment/frequent monitoring (n = 17); (b) noncontingent payment/frequent monitoring (n = 16); or (c) non-contingent payment/infrequent monitoring (n = 14). Contingent payment combined with frequent CO monitoring delayed but did not ultimately prevent subjects relapse to smoking by the end of the six month follow-up. Contingent subjects maintained CO values less than or equal to 11 ppm significantly longer than did either the Non-contingent or the Control subjects (p = .03). CO monitoring alone had no effect on abstinence outcomes; both Noncontingent and Control subjects showed high rates of early relapse.

Contingent payment procedures for smoking reduction and cessation.

We assessed the ability of a combined contingent reinforcement and intensive monitoring procedure to promote and sustain temporary smoking cessation among 34 hired research volunteers, and the ability of a smoking reduction test to predict the subsequent initiation of abstinence. During the 5-day cutdown test, subjects were paid from $0 to $6 per day depending on the extent of reduction from baseline CO levels. During the abstinence test, breath samples were obtained three times daily and subjects were paid $4 for each CO reading less than or equal to 11 ppm. Sixty-eight percent of subjects initiated abstinence. Of the breath samples collected during the abstinence test (91% of scheduled samples), 96.5% were less than or equal to 11 ppm and 80.5% were less than or equal to 8 ppm. Subjects who earned more money during the cutdown test were more likely to abstain (r = -0.51, p less than .001). Contingent reinforcement and intensive monitoring procedures appear to have usefulness for analog studies of smoking reduction and cessation.

The sopite syndrome revisited: drowsiness and mood changes during real or apparent motion.

The sopite syndrome is a poorly understood response to motion. Drowsiness and mood changes are the primary characteristics of the syndrome. The sopite syndrome can exist in isolation from more apparent symptoms such as nausea, can last long after nausea has subsided, and can debilitate some individuals. It is most likely a distinct syndrome from "regular" motion sickness or common fatigue, and is of potential concern in a variety of situations. The syndrome may be particularly hazardous in transportation settings where other performance challenges (e.g., sleep deprivation) are already present. It is also a potential concern in cases where illnesses such as sleep disorders or depression may interact with the syndrome and confuse diagnosis.

The roles of handedness and stimulus asymmetry in aesthetic preference.

When some pictures are mirror reversed, aesthetic evaluations of them change dramatically. Stimulus features that may be important in contributing to this effect are: (a) location of areas of principal interest or weight in the picture space, (b) cues that suggest a direction of motion within the picture. Dextrals and inverted sinistrals preferred paintings with cues suggesting motion proceeding from left to right over their mirror-reversed versions and also preferred those with weight concentrated in the left portions of the picture space. The explanation that best fits these data is that preference is promoted when the picture content encourages attention to its rightmost portions, thus placing a majority of the picture in the left visual field where it is directly processed by the right hemisphere.

Lateral specialization of a perpetual calendar task by a moderately mentally retarded adult.

The lateral eye movements of a moderately mentally retarded adult with exceptional ability in a perpetual calendar task were examined. Questions with a perpetual calendar, mathematical, or musical and spatial content were presented to the subject in a random order and lateral eye movements were rated by blind observers. Results showed that both the perpetual calendar and mathematical questions elicited a significant proportion of lateral movements to the right, ps less than .001 and .05, respectively, whereas the musical and spatial questions did not elicit lateral eye movements with a specific direction.

Paired in vivo and in vitro comparison of apheresis and "recovered" platelet concentrates stored for 5 days.

Using a paired study, in vivo and in vitro characteristics of apheresis platelets collected on a cell separator and single-donor whole-blood (recovered) platelets via platelet-rich plasma (PRP) were compared after storage for 5 days in similar plastic containers. Autologous platelets from each of 12 volunteers were labeled with 111Indium after storage and reinjected. There was no significant difference in circulating recovery between platelets prepared by the two methods, and only one of five models of survival showed a significant difference. Hypotonic shock recovery was significantly better in apheresis than recovered platelets (57.0% and 32.4%, respectively), whilst aggregation to ADP at 3.2 microM and 32 microM was significantly higher in recovered than in apheresis platelets (17.0% and 45.2% versus 7.8% and 32.9%, respectively). Lactate dehydrogenase (LDH) content was significantly higher in recovered platelets (143.3 versus 77.1 IU/10(11) platelets), but LDH release was similar (15.0% cf. 12.6%). There was no significant difference between the two platelet preparations for platelet concentration, pH, aggregation with the calcium ionophore A23187 or collagen plus epinephrine, or ATP content or release. beta-TG release was lower in apheresis platelets. Neither product was consistently better than the other for the parameters tested, but apheresis platelets have the advantage of lower donor exposure to the patient.

A comparative study in volunteers of apheresis and buffy coat derived platelets.

It is important that, at the time of transfusion, platelets prepared by different techniques are effective in vivo and meet acceptable criteria. A paired study was undertaken in 8 volunteer donors to compare apheresis platelets collected on the COBE Spectra with platelets derived from the buffy coat of whole blood donations after 5 days storage. In vivo recovery, survival and biodistribution were determined following indium-111 labelling of the platelets and autologous infusion into volunteers together with the in vitro evaluation of platelet function and biochemistry. The in vivo and in vitro characteristics of both types of platelet concentrate were not significantly different. Both products were equally viable after 5 d storage and both were of an acceptable quality as judged by currently used platelet products. Mean platelet survival (multiple hit) was 5.4 d for the apheresis platelets and 6.9 d for the buffy coat derived platelets and maximum recovery in circulation was 28.1% and 34.8%, respectively. There was a significantly higher platelet yield, as expected, from apheresis and a 1.5 log lower level of white cell contamination. This would be advantageous for patients in need of prolonged or recurrent transfusions as the number of donor exposures and the risk of alloimmunisation or viral transmission would be reduced.