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Biomedical subjects

R Buzzi

Publications and source records attributed to R Buzzi.

72 records · Page 4Linked to original sources
PubMed1983

Cardiovascular effects of smoking cigarettes with different nicotine deliveries. A study using multilead plethysmography.

The purpose of this investigation was to assess the impact of smoking cigarettes with different nicotine deliveries on the subcutaneous blood vessels at different sites of the body. Individual puffing behavior, estimated mouth intake of nicotine, and some personality traits were taken into account. Each of 15 female smokers was presented with four different smoking conditions in order to vary the nicotine uptake. Heart rate and five photoplethysmographic recordings were taken simultaneously and continuously. The heart rate increases were dependent on the individual mouth intake of nicotine. The smoking-induced decreases in the pulse amplitudes failed to show a significant dependency on the nicotine dose. However, the vasoconstrictive response to nicotine was considerable with the finger recordings, modest with the foot recordings, and absent with the forehead and the ear recordings. Furthermore, the magnitude of this vascular response at the finger correlated positively with personality traits of neuroticism, suggesting an explanation for the poor correlations with the dose of nicotine.

Adult↗
PubMed1983

Idiopathic osteonecrosis of the knee. Aetiology, prognosis and treatment.

This is a prospective study of 105 knees in 91 patients with idiopathic osteonecrosis of the femoral condyles, with an average follow-up of five years in 101 knees. Forty-eight of the 75 patients in whom the body weight was studied were obese and four of the 33 patients in whom a densitometry study was done showed decreased bone density. Prognosis is unfavourable if the lesion is larger than five square centimetres and if its width is more than 40 per cent of that of the condyle. Of the 22 patients followed up after conservative treatment 80 per cent were satisfactory. Of the 11 knees treated by arthrotomy alone 55 per cent were satisfactory. Of the 31 knees treated by osteotomy (21 with associated arthrotomy) 87 per cent were satisfactory. Arthrotomy did not significantly improve the results of osteotomies. The ideal correction was to 10 degrees of valgus. Of the 37 knees treated with replacement 95 per cent were satisfactory, and the best results were obtained with the total-condylar prosthesis.

Adult↗
PubMed1983

Psychophysiological correlates of conflict solving and cigarette smoking.

Twenty-eight subjects participated in three sessions which involved three successive rows of STROOP stimuli presented in a spaced trial technique. The first session was a training session, and in the second and third sessions the subjects had to smoke in balanced sequence a 0.2 mg and a 1.2 mg nicotine cigarette between the second and third rows of STROOP stimuli. For these two smoking sessions these experimental subjects were compared with a yoked-control group which attended the task passively without responding to the stimuli but also had to smoke a 1.2 mg nicotine cigarette. Continuous psychophysiological recording showed: (a) Before smoking the heart rates were lower in the yoked than in the experimental subjects. (b) A gradual but modest habituation of intrasession heart rate and EEG measures developed in all experimental groups. (c) Pronounced skin conductance and vasoconstrictive responses to the STROOP stimuli persisted in the experimental groups without any tendency to habituate and without modification by smoking. (d) Significant smoking-induced tachycardia and cutaneous vasoconstriction were seen in the yoked subjects only. Behaviorally, puffing style of smoking was intensified in the experimental group as opposed to the yoked group, and smoking neither impaired nor improved STROOP performance.

Adult↗
PubMed1982

Smoke yield of cigarettes and puffing behavior in men and women.

Puffing behavior (number of puffs, puff interval, puff duration, peak pressure, latency to peak pressure, average and total puff volume) was measured in 67 dependent male and 43 dependent female smokers when they smoked two cigarettes of their habitual brand under laboratory conditions. Test-retest reliability for the two cigarettes was high, and factor analysis showed that puff shape, puff volume, and puff frequency accounted for about 50% of variation obtained with the different puffing variables. Expiratory tidal CO levels increased with the number of cigarettes smoked before the tests and with the intensity of the smoking habit, but pre- to postsmoking delta tidal CO differences were similar for smokers of all types of cigarettes (0.1 - 1.7 mg standard machine smoking nicotine yield). Volume compensation for differences of smoke yield of the cigarettes was generally more pronounced in women than in men and, additionally, it was more pronounced for cigarettes with standard smoke nicotine yield below 0.9 mg than for cigarettes with standard smoke nicotine yield above 0.9 mg for both sexes. Only for women, partial correlation procedures suggested that nicotine might be more important in determining puffing behavior than CO and condensate yield, but there were also no women smoking the strongest cigarettes (1.3 - 1.7 mg nicotine yield). For both sexes, no compensation by adjusting the number of cigarettes smoked daily was obtained. Personality ratings, pulmonary functions, and cardiovascular functions were not, or only inconsistently, correlated with puffing behavior or type of cigarette.

Adolescent↗
PubMed1982

Effects of chlordiazepoxide and imipramine on maze patrolling within two different maze configurations by psychogenetically selected lines of rats.

Male rats of two lines of rats psychogenetically selected and bred for extremes in performance in shuttle box avoidance received an acute IP injection of chlordiazepoxide (CDP; 2.5, 5.0, 10.0 mg/kg), imipramine HCl (IMI: 0.33, 1.0, or 3.0 mg/kg), or vehicle. The rats were placed, 35 min after injection, in an enclosed maze with either a simple configuration with an unilluminated central arena or a complex configuration with a brightly illuminated central arena, and spontaneous maze patrolling was evaluated. Total locomotor activity during the 6-min maze test was significantly reduced by 5--10 mg/kg CDP for both RHA/Verh and RLA/Verh lines of rats in both the simple and the complex maze configurations. Treatment with 10 mg/kg CDP reduced the total explored area for both rat lines in both maze configurations. In addition, the maze area explored by RHA/Verh rats was also reduced by 5.0 mg/kg CDP for the simple configuration and by 2.5 and 5.0 mg/kg CDP for the complex configuration. Entry into the unilluminated central field of the simple maze was reduced by 5--10 mg/kg CDP only in RHA/Verh rats. In contrast, 2.5 mg/kg CDP significantly increased entry into the brightly illuminated central arena of the complex maze for the RLA/Verh rats. The doses of IMI used were without effect on the parameters of maze patrolling behavior evaluated, with the single exception that the locomotor activity of RHA/Verh rats tested in the simple maze configuration was decreased by 3.0 mg/kg IMI. The results indicate that, although the effects of CDP were generally similar for total activity and the area explored in the two psychogenetic lines investigated, there was a qualitative difference in its effect on entry into an illuminated arena.

Animals↗
PubMed1982

[Effects of ethyl alcohol and caffeine on the intensity of cigarette smoking].

Cigarette puffing behavior and depth of inhalation (expired CO) were compared after ethanol, caffeine and placebo treatments. Ethanol in the dose of 0.7 g/kg intensified smoking, enhancing CO-uptake, puff volume per cigarette and average puff volume. Neither ethanol in the dose of 0.5 g/kg nor caffeine in the dose of 5 mg/kg influenced cigarette smoking behavior.

Caffeine↗
PubMed1982

Physiological responses to noise and to the type of activity under field conditions.

Airport area residents were monitored in their private homes for ECG, skin conductance, and respiration during testing sessions of about 1 1/2 hours. All recorded data were analyzed individually. Noise as well as the ongoing activities of the subjects, consisting of mental concentration, scalometric noise assessment, relaxation, and conversation caused significant shifts of the vegetative tonus in most of the subjects. It seems, therefore, that habituation to noise does not develop for this type of environmental noise.

Aircraft↗
PubMed1982

Data collection, computation and statistical analysis in psychophysiological experiments.

The system was designed to allow simultaneous monitoring of eight bioelectrical signals together with the necessary event markers. The data inputs are pulse code modulated, recorded on magnetic tape, and then read into a minicomputer. The computer permits the determination of parameters for the following signals: electrocardiogram (ECG), respiration (RESP), skin conductance changes (SCC), electromyogram (EMG), plethysmogram (PLET), pulse transmission time (PTT), and electroencephalogram (EEG). These parameters are determined for time blocks of selectable duration and read into a mainframe computer for further statistical analysis.

Electrophysiology↗
PubMed1981

[Analysis of smoking behavior in cigarette smokers].

Cigarette puffing behavior and depth of inhalation (expired CO) were measured in 110 non successful abstainers when smoking their habitual brand. CO-uptake was similar for smokers for all types of cigarettes (0.1-1.7 mg nicotine yield).

Carbon Monoxide↗
PubMedDate not supplied

Arthroscopic partial meniscectomy in the anterior cruciate deficient knee.

One hundred ACL insufficient knees were followed for an average of 3.5 years after arthroscopic partial meniscectomy had been performed. Fifty-two percent of the patients obtained a satisfactory result and 41% were able to participate in strenuous sports activities. The arthroscopic partial meniscectomy reduced pain and swelling in a high proportion of cases, but stability was only marginally improved. Negative prognostic factors were: sex (female), generalized laxity, contralateral recurvatum of more than 10 degrees, complete as opposed to partial ACL lesions, Grade III tibiofemoral or patellar chondromalacia, associated peripheral ligamentous laxity, pivot shift of Grade II or greater, and anterior tibial displacement of more than 5 mm as measured with the KT-1000 knee arthrometer.

Adult↗
PubMedDate not supplied

Long-term study of anterior cruciate ligament reconstruction for chronic instability using the central one-third patellar tendon and a lateral extraarticular tenodesis.

Forty-four patients with symptomatic chronic anterior cruciate ligament instabilities that had been reconstructed with the central one-third patellar tendon and a lateral extraarticular iliotibial band tenodesis were studied at an average followup of 7 years (range, 4 to 10). The cases with associated medial, lateral, or posterior laxity were not included, nor were the cases with more than minimal preoperative degenerative changes. The average age at surgery was 21 years (range, 16 to 33). A postoperative cast was used for 4 weeks. Satisfactory objective stability, which was defined as a KT-1000 side-to-side difference of up to 5 mm at the manual maximum test, was obtained in 37 (84%) of the patients. In 25 patients (57%), stability was restored within normal limits (less than or equal to 3 mm). No deterioration of the KT-1000 stability was noted at two follow-up visits performed by the same examiner (at an average of 4 and 7 years). A return to high-risk sports was possible in 27 (62%) of the patients. Difficulties in regaining a complete range of motion were recorded in 5 (11%) of the patients. A flexion contracture of 5 degrees to 7 degrees was also found in 5 patients. Significant patellofemoral symptoms were present in 4 patients (9%). A 5% to 11% shortening of the patella tendon was observed in 14 (32%) of the knees, but did not correlate with patellar problems. Moderate radiographic changes were noted in eight patients (18%) at followup and correlated with meniscectomy and pain. Overall satisfactory results were obtained in this initial experience in 29 (66%) of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Patellar tendon versus doubled semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction.

The results of intraarticular anterior cruciate ligament reconstruction with either the patellar tendon or the semitendinosus and gracilis tendons (four strands) were prospectively compared in a consecutive series of 60 patients with chronic injuries. A single surgeon performed arthroscopically assisted reconstructions in an alternating sequence. Preoperative and operative data revealed no significant differences between the two groups. After 28 months of followup there were no significant differences in the incidence of symptoms, and recurrent giving way was present in only one knee with semitendinosus and gracilis tendon graft. Return to sport participation was more frequent in the patellar tendon group (80% versus 43%, P < 0.01). A minor extension loss (< or = 3 degrees) was more frequent in the patellar tendon group (47% versus 3%, P < 0.001). Other differences between the two groups were not significant. KT-2000 arthrometer side-to-side difference of anterior displacement > 5 mm at 30 pounds was present in 13% of the knees with patellar tendon grafts and in 20% of those with semitendinosus and gracilis; a patellofemoral crepitation developed in 17% and 3% of the two groups, respectively. Based on these data we routinely use patellar tendon grafts. Semitendinosus and gracilis tendons are preferred in selected cases: older patients, patients with preexisting patellofemoral problems, and those with failed patellar tendon grafts.

Anterior Cruciate Ligament↗
PubMedDate not supplied

Arthroscopically assisted semitendinosus and gracilis tendon graft in reconstruction for acute anterior cruciate ligament injuries in athletes.

We evaluated 69 arthroscopically assisted anterior cruciate ligament reconstructions for acute tears at an average followup of 60 months. We used a distally based single semitendinosus and gracilis tendon graft passed over the top and fixed to the femur. Combined medial collateral ligament lesions were seen in 30 knees, and they were repaired when found in the distal third (18 knees). The patients were instructed to recover motion preoperatively, and an early range of motion program was used postoperatively. At followup, symptoms of giving way were seen in five knees (7%). Graft failure was seen in seven knees (10%); failure was defined as a positive pivot shift (clunk or gross) or a side-to-side difference in anterior tibial displacement greater than 5 mm, as measured with a KT-1000 arthrometer. Permanent extension loss (3 degrees to 5 degrees) was found in two knees (3%). Patellofemoral crepitation was seen in eight knees (12%), but the condition was symptomatic in only one knee. Forty-six patients (67%) were active in pivoting sports before surgery and 37 (54%) remained active in these sports at followup. We concluded that this operation is simple, effective, and has a low complication rate. Further studies are necessary to elucidate if a stronger graft (e.g., a patellar tendon) would decrease the rate of graft failure without increasing complications.

Acute Disease↗
PubMedDate not supplied

Construction of diagnostic rules based on assessments of subjects.

This paper is based on assessments of subjects which are not defined by formal procedures. Logically structured assignment rules are constructed which are stable over time and which have a low number of disagreements with the assessments of the subjects. Recent results obtained from a computational learning theory show that the proposed construction of rules leads with high probability to rules with similar performances on large enough learning and validation sets of subjects. The construction of a set of stable rules is illustrated by using as a case study the psychophysiological, personality and speech behaviour data of a repeated-measures Type A behaviour study. This case study is also used for a discussion of the issue of biased ratings in the presence of assessments which are not defined by formal procedures.

Adult↗
PubMedDate not supplied

A field study on vegetative effects of aircraft noise.

Sound level, electrocardiogram, electromyogram, skin conductance, and respiration were recorded under field conditions in 33 airport area residents. During the rcordings, the subjects had to perform different activities (e.g., filling out forms, concentration test, noise assessment, relaxation, and direct conversation with the experimenter). The different activities caused significant shifts in clusters of physiological data in all subjects. Aircraft noise and incidental background noise caused such shifts in the majority of subjects. Subsequent correlational and cluster analysis for the effects of sound intensity revealed interactions with the type of ongoing activity. Vegetative noise responsiveness was not correlated with noise exposure level and subjective complaint behavior, but was correlated with vegetative responsiveness to the different ongoing activities.

Adult↗