REGIONAL DISTRIBUTION OF 11C-LABELED LIDOCAINE,BUPIVACAINE, AND ROPIVACAINE IN THE HEART,LUNGS, AND SKELETAL MUSCLE OF PIGS STUDIED WITH POSITRON EMISSION TOMOGRAPHY

The regional myocardial uptake and kinetics of ¹¹C-lidocaine, ¹¹C-bupivacaine, and ¹¹C-ropivacaine were examined in the pig, utilizing positron emission tomography to determine whether disproportionate distribution exists among these agents. The three drugs were rapidly distributed to the myocardium and lung with mean peak radioactivities occurring between 0·35 and 0·48 min post-injection in myocardium and 0·35 and 0·65 min in lung. Radioactivities peaked later in skeletal muscle than in the myocardium and lung, occurring between 1·1 and 2·7 min post-end injection. Blood radioactivities for bupivacaine and ropivacaine were significantly higher than those of lidocaine, whereas myocardial, lung, and muscle uptakes for the three agents were not significantly different. Myocardium–blood partition coefficients were similar for bupivacaine and ropivacaine (0·55 and 0·49 respectively), while it was three times higher for lidocaine (1·4). A similar relationship existed for skeletal muscle– and lung–blood partition coefficients. Bupivacaine and ropivacaine t_1/2z in skeletal muscle were significantly longer than those of lidocaine. The results of this study indicate that the increased cardiotoxicity associated with bupivacaine does not appear to be related to disproportionate distribution in the myocardium when compared to lidocaine and ropivacaine. © 1997 by John Wiley & Sons, Ltd.     

Ethanol Reduces Myoglobin Release during Isokinetic Muscle Exercise

ABSTRACT. Changes in serum myoglobin concentrations were studied in 12 healthy males performing a standardized isokinetic 2-min exercise test. The test was performed on three separate occasions: in the habitual state, during moderate ethanol intoxication and one day after ethanol intake. Although the performed muscle work, maximal heart rate, and blood lactate levels did not differ between the three test occasions, the serum myoglobin increments after exercise were significantly reduced (p < 0.05) in the ethanol-intoxicated state and also 10–15 hours after ethanol intake. The reduction of the exercise-induced myoglobin increment was not explained by increased elimination of the protein. The mechanism, therefore, is likely to be a reduction of myoglobin release from skeletal muscle due to an ethanol-induced alteration of the muscle cell membrane, possibly by means of adenylate cyclase activation.     

Significance of Late Recurrence of Atrial Fibrillation during Long-Term Follow-Up after Pulmonary Vein Isolation

Background and Study Objective : Patients with paroxysmal or persistent atrial fibrillation (AF) can be treated by pulmonary vein (PV) isolation. Although the recurrence rate after the procedure is relatively high, the long-term outcomes after initially recurrence-free procedures remains unclear. We examined the rates of recurrence of AF after PV isolation.
Methods: Our study included 278 consecutive patients with drug-refractory AF (mean age = 53 ± 11 years, 228 men). PV isolation was based on the disappearance of PV potentials recorded from a circumferential catheter after segmental ostium ablation. Cavo-tricuspid isthmus lines and additional atrial lines were performed in 124 and 28 patients, respectively. Patients were monitored for a mean of 26 ± 11 months (range 12–56). Recurrence was defined as ≥1 episodes of symptomatic or asymptomatic AF >1 month after the procedure.
Results: A total of 120 (34) patients had ≥1 recurrence of AF >1 month after the procedure, of whom 14 (4) had a first recurrence >6 months after the procedure. There was a significantly higher recurrence rate among patients with persistent AF.
Conclusions : A relatively high AF recurrence rate was observed after PV isolation. AF may recur late after the ablation procedure, though the majority of recurrences occurred within 6 months after the first procedure. There were no differences in incidence or time of occurrence of late recurrences between patients with paroxysmal versus persistent AF.     

Measurement by observations of aggressive behaviour and activities in clinical situations

Clinical aggression (towards self or other persons or things) is often thought of as having a certain degree of disease specificity. Thus, suicidal ideation is often associated with major depression, self-mutilation with borderline personality disorder, hostility with mania, negativism with schizophrenia or dementia and violence with explosive—impulsive disorder. Attempts to measure suicidal behaviour have pointed at the dimension of depression. Attempts to measure self-mutilation have shown that this is a behaviour without association to depression or suicidal behaviour. It seems to be associated with borderline disorders as well as mental handicaps. Attempts to measure outward aggression in the clinical situation have identified an aggression factor very similar to that found in the general population by Buss (1971) . This includes passive versus active aggression, direct versus indirect aggression, and verbal versus physical aggression. Among the clinical rating scales the nine-items Social Dysfunction and Aggression Scale (SDAS-9) covers this construct. Furthermore, the SDAS-9 measures both the generalised (day-to-day) aggression and aggressive acts. The scale is administered by the psychiatrist in collaboration with the nursing staff. Among scales specifically designed to be administered by the nursing staff are the Overt Aggression Scale (OAS), the Staff Observation Aggression Scale (SOAS), and the Scale for Assessment of Agitated and Aggressive Behaviour (SAAB). These three scales differ in the aspects of aggression to be measured and in the extent to which risk factors are considered. Among psychopathological risk symptoms are delusions, hallucinations, and lack of insight. Among other risk factors are medication and activities of daily living in the ward (ADL). It is important to differentiate in the measurement between aggressive behaviour and risk factors. Thus, the SDAS-9 measures aggressive behaviour (generalised and attacks), the Brief Psychiatric Rating Scale (BPRS) or the Maudsley Assessment of Delusion Schedule (MADS) measure psychopathological risk factors (e.g. delusions and hallucinations), and the SOAS measures other risk factors (e.g. medication and ADL) .     

Young hospital doctors after night duty: their task-specific cognitive status and emotional condition

Summary: Sleep deprivation is an unpleasant burden of young hospital doctors during their medical training. It may disrupt the balance between coping strategies available to them and the professional demands encountered. Impaired medical care offered by sleep-deprived juniors may be a consequence. Valid research work on this subject is rare and surprisingly contradictory. Therefore, we evaluated the task-specific cognitive status and emotional condition of 40 young hospital doctors (27 men and 13 women, 29.9 ± 2.9 years of age) at the University of Tuebingen, all of whom were in the beginning of their academic career. Subjects were tested twice acting as their own control, once at 8.00 am after a night off duty (OD) (at least 6 hours of uninterrupted sleep), and once at a similar time after a night on call (OC) being in the hospital for 24 hours. Standardized and reliable psychometric tests thought to represent daily routine medical function were performed. On-call activities were recorded by means of a sleep diary, whereas a questionnaire interrogated aspects of private and professional life. Neuropsychological function deteriorated significantly: number connection test (per cent of norms ± SD, 103.2 ± 9.8 OC vs 107.8 ± 10.5 OD, F = 27.7, P < 0.001), things-to-do list (correct items ± SD, 6.7 ± 1.2 OC vs 7.4 ± 1.5 OD, F = 12.7, P < 0.01), Vienna reaction timer (per cent of norms ± SD, 95.6 ± 9.0 OC vs 97.7 ± 10.4 OD, F = 4.8, P < 0.05), Stroop test (T-values ± SD, 59.7 ± 6.3 OC vs 64.6 ± 7.1 OD, F = 37.1, P < 0.001), ECG test (correct responses ± SD, 38.3 ± 7.3 OC vs 43.4 ± 6.5 OD, F = 45.2, P < 0.001) and status of mood (T-value ± SD, 60.3 ± 9.0 OC vs 54.0 ± 6.6 OD, F = 19.6, P < 0.001). Cognitive function and mood status of young hospital doctors after a night on call decrease considerably. In view of the special vulnerability of medical trainees to occupational stress all efforts are warranted to reduce sleep deprivation in the medical profession.     

The plaque-removing effect of four toothbrushing methods

abstract – Two experimental studies were carried out to compare the plaque-removing ability of three well-known tooth-brushing methods (the roll, the horizontal scrub, and Charters') and brushing with a singletufted brush, the interbrush method. After withdrawal of all oral hygiene measures for three days, the teeth were brushed by a dental hygienist employing one of the methods in each quadrant of the mouth. The brushing was performed with brushes recommended for the different methods. Immediately after the brushing, the remaining plaque was assessed according to the Plaque Index. The brushing methods tested showed negligible effect on interdental plaque accumulations. This was valid both in dental students with healthy periodontal conditions and in periodontally treated persons. Vestibularly and lingually more plaque was left after brushing with the roll method than after brushing with any of the other methods. The differences between the horizontal scrub, the Charters', and the interbrush methods were small. Time studies revealed that the horizontal scrub was the least time-consuming method. The roll method required a little more time, but less than Charters'method, whereas the interbrush method was more time-consuming than any of the other methods tested.     

Dose-dependent Subcutaneous Absorption of Porcine,Bovine and Human NPH Insulins

ABSTRACT The absorption of ¹²⁵I-labelled porcine, bovine and human neutral protamine Hagedorn (NPH) insulins was compared in 40 diabetic patients after subcutaneous injections in the thighs using doses of 6 and 24 IU (40 IU/ml). Furthermore, the absorption of porcine NPH insulin was compared with bovine NPH insulin and porcine lente type insulin in the same dose (6 IU). All these intermediately acting insulins showed similar absorption rates when administered in the same dose. However, an increase in the injected dose from 6 to 24 IU resulted in a decrease of approximately 30% in the absorption rate of all NPH insulins.     

Responses of single arterioles in vivo in cat skeletal muscle to change in arterial pressure applied at different rates

The concept of a rate-dependent, dynamic as well as a static component in the myogenic control has been suggested in some previous in vitro and whole organ investigations. The present study is an attempt to reveal a dynamic component in the myogenic response directly on single arterioles by a vital microscopic technique. The study was made on the autonomically blocked vascular bed of cat tenuissimus muscle and performed by analysing the arteriolar diameter changes to an arterial pressure increase and decrease when applied at two different rates. The results demonstrate a transient, dynamic constrictor response upon the phasic increase in pressure and a transient, dynamic dilator response upon the phasic decrease in pressure, the magnitudes of which being related to the rate of the pressure change. The static response developing during the steady-state phase of constant increased pressure was also shown. The dynamic responses were confined to arterioles smaller than about 20 μm while the steady-state response was present in larger arterioles as well. Even if the metabolic control system partly could be responsible for the obtained responses, arguments are given that the described reactions are mainly myogenic in nature.     

Serum IgE in infants and influence of type of feeding

Serum IgE in healthy infants was followed longitudinally during the first year of life and was related to heredity for allergy and type of feeding. During the first 6 months of life there were no significant differences of serum IgE levels in relation to presence or absence of heredity for allergy and type of feeding. IgE levels determined at the age of 12 months in infants who were weaned after the age of 6 months were significantly higher than in infants weaned before that age (P<0.05). When the time periods had passed, following onset of cow's milk-feeding and complete cessation of breast-feeding, and were correlated to IgE at the age of 12 months, there were inverse significant correlations; i.e. the earlier the onset of cow's milk-feeding the lower the IgE and the later the cessation of breast-feeding the higher the IgE. This was particularly obvious as regards infants with heredity for allergy and a long duration of breast-feeding (r=?0.43; P<0.01). Infants with heredity for allergy subjected to a hypoallergenic diet adhered to for 6 months had significantly higher IgE at the age of 12 months than infants with similar heredity but a normal diet (P<0.05). The results indicate that serum IgE during late infancy is influenced by both genetic factors and the time of introduction of cow's milk formula in the diet and the time of cessation of breast-feeding.