A standardized blood sampling scheme in quantitative FDG-PET studies

Quantitative estimation of brain glucose metabolism (rCMRGlc) with positron emission tomography and fluorodeoxyglucose involves arterial blood sampling to estimate the delivery of radioactivity to the brain. Usually, for an intravenous injection of 30 s duration, an accurate input curve requires a frequency of one sample every 5 s or less to determine the peak activity in arterial plasma during the first 2 min after injection. In this work, 13 standardized sampling times were shown to be sufficient to accurately define the input curve. This standardized input curve was subsequently fitted by a polynomial function for its rising part and by spectral analysis for its decreasing part. Using the measured, the standardized, and the fitted input curves, rCMRGlc was estimated in 32 cerebral regions of interest in 20 normal volunteers. Comparison of rCMRGlc values obtained with the measured and the fitted input curves showed that both procedures gave consistent results, with a maximal relative error in mean rCMRGlc of 1% when using the autoradiographic method and 2% using kinetic analysis of dynamic data. This input-curve-fitting technique, which is not dependent on the peak time occurrence, allows an accurate determination of the input-curve shape from reduced sampling schemes.

Lipectomy, body weight, and body weight set point in rats

Adult, Wistar male rats were lipectomized or sham lipectomized. The food-hoarding behavior was measured repeatedly and plotted against the animals' body weights. Body weight set point was estimated as the intercept of regression line of hoarding with the X axis. Body fat content was measured with a TOBEC body composition analyzer. Body weight set point, fat content, and girth were obtained initially, after surgery, and after recovery. The hoarding threshold was lowered for 2 weeks after surgery, from 561 +/- 20 to 512 +/- 19 g (lipectomized), and from 582 +/- 15 to 558 +/- 14 g (sham lipectomized). After a 4-week recovery, all rats reached their prelipectomy body weight set point and regained their initial body fat. Five weeks after surgery, no significant difference was found between the body weight set points of lipectomized and sham-lipectomized rats. This indicates that the body weight set point was not mainly modulated by fat depots. The transient lowering of the set point is thought to be due to surgical stress.

Changes in occipital cortex activity in early blind humans using a sensory substitution device

The purpose of this study was to investigate the neural networks involved when using an ultrasonic echolocation device, which is a substitution prosthesis for blindness through audition. Using positron emission tomography with fluorodeoxyglucose, regional brain glucose metabolism was measured in the occipital cortex of early blind subjects and blindfolded controls who were trained to use this prosthesis. All subjects were studied under two different activation conditions: (i) during an auditory control task, (ii) using the ultrasonic echolocation device in a spatial distance and direction evaluation task. Results showed that the abnormally high metabolism already observed in early blind occipital cortex at rest [C. Veraart, A.G. De Volder, M.C. Wanet-Defalque, A. Bol, C. Michel, A.M. Goffinet, Glucose utilization in human visual cortex is, respectively elevated and decreased in early versus late blindness, Brain Res. 510 (1990) 115-121.] was also present during the control task and showed a trend to further increase during the use of the ultrasonic echolocation device. This specific difference in occipital cortex activity between the two tasks was not observed in control subjects. The metabolic recruitment of the occipital cortex in early blind subjects using a substitution prosthesis could reflect a concurrent stimulation of functional cross-modal sensory connections. Given the unfamiliarity of the task, it could be interpreted as a prolonged plasticity in the occipital cortex early deprived of visual afferences.

Severe cutaneous hypersensitivity requiring permanent icodextrin withdrawal in a CAPD patient

We report a case of severe cutaneous hypersensitivity to icodextrin occurring in a CAPD diabetic patient. Icodextrin withdrawal was necessary to achieve cutaneous recovery. Although rare, this adverse event should be kept in mind.

Effect of familiarity on the processing of human faces

Most brain imaging studies on face perception have investigated the processing of unknown faces and addressed mainly the question of specific face processing in the human brain. The goal of this study was to highlight the effects of familiarity on the visual processing of faces. Using [15O]water 3D Positron Emission Tomography, regional cerebral blood flow distribution was measured in 11 human subjects performing an identical task (gender categorization) on both unknown and known faces. Subjects also performed two control tasks (a face recognition task and a visual pattern discrimination task). They were scanned after a training phase using videotapes during which they had been familiarized with and learned to recognize a set of faces. Two major results were obtained. On the one hand, we found bilateral activations of the fusiform gyri in the three face conditions, including the so-called fusiform-face area, a region in the right fusiform gyrus specifically devoted to face processing. This common activation suggests that different cognitive tasks performed on known and unknown faces require the involvement of this fusiform region. On the other hand, specific regional cerebral blood flow changes were related to the processing of known and unknown faces. The left amygdala, a structure involved in implicit learning of visual representations, was activated by the categorization task on unknown faces. The same task on known faces induced a relative decrease of activity in early visual areas. These differences between the two categorization tasks reveal that the human brain processes known and unknown faces differently.

Isolation of an acid fraction from a fish protein hydrolysate with a calcitonin-gene-related-peptide-like biological activity

The possibility of obtaining calcitonin and/or calcitonin-gene-related peptide (CGRP) immunorelated molecules from partly digested proteins was investigated with fish and shrimp hydrolysates. These two peptides were quantified by both radioimmunoassay and radioreceptor assay; the positive extracts were partly purified. Different hydrolysates were analysed: cod head, stomach and viscera hydrolysates, a shrimp hydrolysate and two sardine hydrolysates. Although each cod extract interacted in the CGRP radioimmunoassay, none of these extracts was able to displace the CT binding to its antibody. In contrast, shrimp and sardine hydrolysates interacted with both radioimmunoassays. Radioreceptor assays performed on the same extracts demonstrated that only three extracts contained the structural determinants that allowed them to interact in the CGRP radioreceptor assay. No interaction with the calcitonin radioreceptor assay could be demonstrated. Molecular sieving of the two sardine extracts showed that the immunoreactivity was resolved into two main fractions. The higher-molecular-mass fraction interacted only in the CGRP radioreceptor assay. The results obtained suggest the presence of a biologically related CGRP molecule in peptone hydrolysates and requires further investigation into the role of these peptide fragments in the regulation of intestinal function by partly digested proteins.

Neuronal mechanisms of perceptual learning: changes in human brain activity with training in orientation discrimination

Using 15O-water 3D positron emission tomography, regional cerebral blood flow was measured twice in six human subjects: before and after extensive training in orientation discrimination. In each session subjects performed two orientation discrimination tasks, during which they discriminated the orientation of a grating at either the trained or untrained reference orientation, and a control task, during which they detected a randomly textured pattern. By comparing the discrimination to the detection tasks, we observed a main effect of task bilaterally in the posterior occipital cortex, extending into the left posterior fusiform gyrus and the right inferior occipital gyrus, bilaterally in the intraparietal sulcus, as well as in the cerebellum, thalamus, and brainstem. When we compared the activation pattern before and after the training period, all the changes observed were activity decreases. The nonspecific changes, which were not related to the orientation used during the training, were situated in the cerebellum and bilaterally in the extrastriate visual cortex. The orientation-specific changes, on the other hand, were restricted to the striate and extrastriate visual cortex, more precisely the right calcarine sulcus, the left lingual gyrus, the left middle occipital, and the right inferior occipital gyrus. These findings confirm our hypothesis concerning the existence of learning related changes at early levels of visual processing in human adults and suggest that mechanisms resulting in neuronal activity decreases might be involved in the present kind of learning.

In Vitroprebiotic effects of Acacia gums onto the human intestinal microbiota depends on both botanical origin and environmental pH

Acacia gums are commonly used food additives. It is currently unclear how extensively these non-digestible polysaccharides are fermented in the human large intestine. However, they have been shown to support bifidobacterial growth in vitro and may represent useful candidate prebiotics. In these investigations, in vitro 24-h batch incubations and chemostat continuous-cultures of human faecal bacteria were conducted using two acacia gums (Fibregum standard and Fibregum AS). Our aim was to study the effects of these gums on bacterial ecology and fermentation in the large bowel. Fructooligosaccharides (Actilight-950P) were also investigated as a reference. Both Acacia gums were extensively fermented by intestinal flora although there were marked differences in fermentation product formation and ecological effects, probably due to their differing botanical origins and/or biochemical characteristics. In particular, fermentation of Fibregum AS led to significantly higher proportions of propionate both in batch and chemostat experiments. Both gums decreased Clostridium sp. levels but only Fibregum-standard induced higher Lactobacillus sp. counts compared to control. These bacterial modifications were highly dependent of the operating pH of the fermentation system with acidic conditions promoting both the prebiotic and the butyrogenic effects of fructooligosaccharides. In these studies, we have demonstrated that, similarly to fructooligosaccharides, Acacia gums can exert putatively beneficial effects on host health through both the improvement of the composition of the large intestine microflora and SCFA formation.

-How to obtain the best results using digitalization-

The main characteristics and the relative interest of the different modalities of medical imaging digitalization are presented as well as their most appropriate clinical indications.

Nitrogen-13-ammonia and oxygen-15-water estimates of absolute myocardial perfusion in left ventricular ischemic dysfunction

Measurements of resting myocardial blood flow (MBF) in patients with chronic left ventricular ischemic dysfunction by 15O-water with 13N-ammonia and PET have yielded conflicting results. The aim of this study was to perform a head-to-head comparison of both tracers in the same patient population and to answer the question of whether distinctive tracer properties account for differences in estimates of MBF in chronically dysfunctional myocardium by both tracers.

METHODS

A total of 30 patients with chronic dysfunction of the anterior myocardial wall due to significant left anterior descending coronary artery disease underwent PET measurements of absolute MBF in the anterior wall by use of 15O-water and 13N-ammonia before coronary revascularization by either coronary artery bypass graft (n = 24) or percutaneous transluminal coronary angioplasty (n = 6). Improvement of regional contractile function was assessed by two-dimensional echocardiography at a mean of 7.5 +/- 2.1 mo after revascularization. As judged from the changes in anterior myocardial wall motion after revascularization, patients were considered to have either reversibly (n = 16) or persistently (n = 14) dysfunctional myocardium. Estimates of MBF by 15O-water and 13N-ammonia, obtained in every patient before revascularization, were compared among the two patient groups by use of previously validated methods.

RESULTS

With 13N-ammonia, resting regional MBF was significantly higher in reversibly as opposed to persistently dysfunctional segments [84 +/- 8 versus 48 +/- 6 ml (min x 100 g)(-1), mean +/- s.e.m., p < 0.01]. By contrast, no such difference was found when using 15O-water to measure MBF [74 +/- 6 versus 86 +/- 9 ml (min x 100 g)(-1), p = ns]. This was mainly due to the fact that the perfusable tissue fraction (PTF), a fitted parameter of the 15O-water model, was significantly higher in reversibly as opposed to persistently dysfunctional segments (0.63 +/- 0.03 versus 0.50 +/- 0.03, p < 0.05). As a consequence, the 15O-water perfusable tissue index (PTI), which is the ratio of the PTF to the anatomical tissue fraction, was greater in reversibly dysfunctional as opposed to persistently dysfunctional segments (1.07 +/- 0.07 versus 0.79 +/- 0.05, p < 0.01).

CONCLUSION

This study demonstrates significant differences in MBF estimates between 15O-water and 13N-ammonia in chronically dysfunctional ischemic myocardium. Our results indicate that the 15O-water method yields higher absolute MBF values than the 13N-ammonia approach. Our results also support the use of PTI as a marker of myocardial tissue viability.

Evolution of brain glucose metabolism with age in epileptic infants, children and adolescents

During the first years of life, the human brain undergoes repetitive modifications in its anatomical, functional, and synaptic construction to reach the complex functional organization of the adult central nervous system. As an attempt to gain further insight in those maturation processes, the evolution of cerebral metabolic activity was investigated as a function of age in epileptic infants, children and adolescents. The regional cerebral metabolic rates for glucose (rCMRGlc) were measured with positron emission tomography (PET) in 60 patients aged from 6 weeks to 19 years, who were affected by complex partial epilepsy. They were scanned at rest, without premedication, in similar conditions to 20 epileptic adults and in 49 adult controls. The distribution of brain metabolic activity successively extended from sensorimotor areas and thalamus in epileptic newborns to temporo-parietal and frontal cortices and reached the adult pattern after 1 year of age. The measured rCMRGlc in the cerebral cortex, excluding the epileptic lesions, increased from low values in infants to a maximum between 4 and 12 years, before it declined to stabilize at the end of the second decade of life. Similar age-related changes in glucose metabolic rates were not observed in the adult groups. Despite the use of medications, the observed variations of rCMRGlc with age in young epileptic humans confirm those previously described in pediatric subjects. These metabolic changes are in full agreement with the current knowledge of the synaptic density evolution in the human brain.

[Rilmenidine in rosacea: a double-blind study versus placebo]

INTRODUCTION

The usual treatments of rosacea (cyclines and metronidazole) are mainly effective on reducing the number of papules and pustules. Clonidine only was employed in order to treat flushes observed in rosacea. Rilmenidine is a central hypotensive drug which acts more specifically than clonidine on imidazoline receptors and which has no sedative side effects. The purpose of this study was to evaluate the efficacy of rilmenidine 1 mg/d in the treatment of rosacea.

PATIENTS AND METHODS

A total of 41 patients suffering from typical rosacea were selected in this randomised double blind study rilmenidine versus placebo. The study comprised an 1-month observation period without treatment followed by 3 months of treatment. The major assessment criteria was the proportion of responders at the end of the treatment period. Responders were defined as patients showing a decrease of more than 50 p. 100 in the count of papules and pustules. Minor criterias were the variation of the number of flushes, self-evaluated by the patient and the variation of the redness of the face, noted by the investigator on a scale from 0 to 5.

RESULTS

Fifteen patients treated by rilmenidine (R) and 19 patients receiving the placebo (P) were evaluated. The proportion of responders was 69.2 p. 100 in group R and 57.1 p. 100 in group P (p = 0.69). The variations of the number of papules and pustules and of the redness of the face were not significantly different in the two groups. The decrease in the number of flushes was higher in group R (around -13) than in group P (around -5), but the difference was not really significant (p = 0.076). Arterial pressure decreased in 3 patients in group R and in 2 patients in group P. Minor side effects were noted in a similar proportion of patients in the two groups.

DISCUSSION

Rilmenidine is not efficient in reducing the number of papules and pustules but could decrease the number of flushes. Nevertheless, many patients were lost for follow-up and because of a major placebo effect, the conclusions of this study are not strong enough. Another study including more patients and using evaluation criteria based on the vascular components of rosacea could perhaps confirm this hypothesis.

[Prediction by means of endogenous and exogenous evoked potentials of the favorable evolution of a prolonged coma]

A neurophysiological follow-up (EEG, exogenous and endogenous evoked potentials--EP) was performed over a 4-month period in a patient who presented a long-lasting coma following a cardiac arrest and an amniotic embolism. A pure anoxic aetiology was ruled out starting from the second day on the basis of a dissociation between mildly altered flash visual EP and markedly altered somatosensory EP, indicating focal brain-stem pathology. Endogenous EP reappeared after 12 days. This patient recovered consciousness after 51 days. Despite the absence of MRI abnormalities, we put forward the hypothesis that a brain-stem embolism had, in fact, worsened the clinical picture of an actually moderate anoxia. This case exemplifies the interest of an integrated neurophysiological approach (EEG, exogenous three-modality EP and endogenous EP) in the early evaluation of coma. It also illustrates the complement between structural imaging and functional assessment of the nervous system.

Prevalence of histological beta2-microglobulin amyloidosis in CAPD patients compared with hemodialysis patients

BACKGROUND

The prevalence of beta2-microglobulin amyloidosis (Abeta2m) in patients on continuous ambulatory peritoneal dialysis (CAPD) is unknown.

METHODS

We prospectively obtained a median of 2 (range 1 to 4) joint samples from 26 CAPD patients aged 44 to 93 (median 73) years at post-mortem evaluation after 4.5 to 126 (median 27) months solely on CAPD (N = 19) or primarily on CAPD (that is, < or = 10% and < or = 1 year of renal replacement therapy time on other modalities; N = 7). The diagnosis of Abeta2m rested on Congo red staining (typical birefringence) and positive immunostaining of amyloid deposits by a monoclonal anti-beta2m antibody.

RESULTS

Abeta2m was diagnosed in 8 of 26 patients (31%). Prevalence ranged from 20% (2 of 10 patients) within < or = 24 months CAPD to 30% (3 of 10 patients) after 24 to 48 months and 50% (3 of 6 patients) after 49 to 126 months (P = 0.11). The prevalence of Abeta2m was similar in patients without or with one or more peritonitis episodes. No significant difference in prevalence (P = 0.118) was found between CAPD patients (8+/26; 31%) and hemodialysis patients (13+/26; 50%) carefully matched for time on dialysis and age at the onset of dialysis.

CONCLUSIONS

The prevalence of histological Abeta2m reaches 31% after a median duration of 27 months of CAPD. This prevalence is not significantly different from that observed in a group of HD patients matched for age and dialysis duration.

Motor perseverations: a function of the side and the site of a cerebral lesion

Motor perseverations are commonly thought to be a sign of frontal lobe lesions, although they may also occur following lesions outside the frontal lobes. Moreover, differences in the type and frequency of motor perseverations between the two cerebral hemispheres have been suggested. Recurrent perseverations (repetition of a previous response to a subsequent stimulus) and continuous perseverations (abnormal prolongation of a current activity) are two different aspects of motor intentional disorders. The former have been associated with left hemispheric lesions, and the latter with right hemispheric lesions. To test this hypothesis, we examined 42 patients with single cerebral lesions of different locations: 22 right hemispheric (7 frontal and 15 extrafrontal) and 20 left hemispheric lesions (8 frontal and 12 extrafrontal), and healthy controls with a graphic task, allowing for analysis of these two types of motor perseverations. We found that (i) both types of perseverations increased significantly for all groups of patients compared to normal controls, except for recurrent perseverations in patients with right posterior lesions, (ii) there was no significant dissociation between the type of perseverations and the side of lesions, and (iii) there was a significant interaction between the type of perseveration, frontal versus extrafrontal location, and the side of a lesion, which is based on the tendency for recurrent perseverations to be increased in left posterior and right frontal lesions, and decreased in left frontal and right posterior lesions, as compared to continuous perseverations. These findings cast doubt about the predominant role of the frontal lobes for motor perseverations, but support the idea of hemispheric specialization in motor control which is, however, more complex than previously thought.

[Protective effect of labetalol on cardiovascular consequences of brain death in the swine]

OBJECTIVE

Assessment of the preventive effect on cardiovascular changes following experimental brain death (BD) in the pig by pretreatment with labetalol, an alpha and beta adrenoreceptor blocking agent.

STUDY DESIGN

Experimental study.

ANIMALS

Ten 25-35 kg domestic pigs allocated either in the control group (n = 5) or the labetalol group (n = 5).

METHODS

BD was achieved in anaesthetized animals by the rapid inflation of a Foley catheter inserted into the sub-dural space. In the labetalol group, the agent (total: 10 +/- 3 mg.kg-1) was administered immediately before BD and thereafter over a 20-min period, in order to maintain haemodynamic parameters at control values. The following haemodynamic data were recorded over a 3 hour period after BD: heart rate (HR), dP/dtmax, mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO) and left anterior descending coronary artery blood flow (CBF). Afterwards, a dynamic loading test with 500 mL of dextran over 20 min was performed.

RESULTS

In the control group, BD elicited a significant increase in HR (from de 96 +/- 9 to 176 +/- 11 b.min-1), dP/dtmax (from 1,960 +/- 123 to 4,904 +/- 930 mmHg.s-1), MAP (from 88 +/- 5 to 119 +/- 11 mmHg), CO (from 2.4 +/- 0.2 to 3.6 +/- 0.7 L.min-1) and CBF (from 45 +/- 6 to 73 +/- 7 mL.min-1) respectively. Apart from a slight increase in HR and a significant increase in CBF (from 34 +/- 4 to 55 +/- 6 mL.min-1), no other modifications occurred in the labetalol group. Following volume expansion, the labetalol group animals experienced a significant increase in CO (from 2.3 +/- 0.3 to 3.7 +/- 0.2 L.min-1), dP/dtmax (from 1,400 +/- 91 to 2,100 +/- 212 mmHg.s-1) and MAP (from 55 +/- 5 to 70 +/- 5 mmHg). In the opposite, a significant decrease in dP/dtmax (from 1,645 +/- 450 to 628 +/- 152 mmHg.s-1) occurred in the control group.

CONCLUSION

The protective effect of labetalol confirms the role played by the activation of the cardiac sympathetic nervous system in the cardiocirculatory changes following BD.

Physical activity, skeletal muscle beta-adrenoceptor changes and oxidative metabolism in experimental chronic heart failure

In chronic heart failure (CHF), changes in sympathetic nervous activity and skeletal muscle metabolism contribute to a limitation in the capacity for exercise. The aim of this study was to investigate the potential relationships between physical deconditioning, skeletal muscle beta-adrenoceptor (beta-AR) characteristics and muscle metabolic changes in rats with coronary ligation-induced experimental CHF. Muscle beta-AR and norepinephrine levels were assessed in rats with CHF that had been treated with propranolol at 28 mg/kg/day and compared with rats with CHF that had not been treated and those that had undergone sham operations. The soleus muscle was investigated because of its predominantly oxidative fibre-type composition. Measurements of spontaneous locomotion activity were carried out using telemetry. After 85 days, muscle energetic phosphate levels were assessed using 31P-magnetic resonance spectroscopy. The phosphocreatine resynthesis rate was decreased in the untreated CHF rats (15 +/- 3 vs 33 +/- 5 mmol L-1 min-1 in the sham-operated rats, p < 0.05), but this had been partially reversed in the rats given propranolol (22 +/- 3 mmol L-1 min-1, non-significant (NS) when compared with the sham-operated rats). Spontaneous activity did not differ among the three groups of animals. Soleus beta-adrenoceptor density was decreased in rats with CHF (8.8 +/- 3.0 fM/mg of protein vs 22.0 +/- 7.0 fM/mg of protein in the sham-operated rats, p < 0.05) and normalized in the propranolol-treated rats (31.9 +/- 7.0 fM/mg of protein, NS vs the sham-operated rats; p < 0.05 vs the untreated rats with CHF). Unchanged spontaneous activity in the rats with CHF suggests that physical deconditioning could not account for the muscle metabolic changes. Changes in skeletal muscle energy metabolism were accompanied by changes in beta-AR density, occurring in typically oxidative beta-AR-rich muscles, reversible after beta-blocker therapy and therefore suggestive of beta-AR downregulation.

PET study of human voluntary saccadic eye movements in darkness: effect of task repetition on the activation pattern

Using H2(15)O 3D Positron Emission Tomography (PET), regional cerebral blood flow (rCBF) was measured in six human subjects under two different conditions: at rest and while performing self-paced horizontal saccadic eye movements in darkness. These two conditions were repeated four times each. First, the comparison between the four saccadic and four resting conditions was investigated in a group and a single subject analysis. Saccades elicited bilateral rCBF increases in the medial part of the superior frontal gyrus (supplementary eye field), precentral gyrus (frontal eye field), superior parietal lobule, anterior medial part of the occipital lobe involving striate and extrastriate cortex (lingual gyrus and cuneus), and in the right inferior parietal lobule. At the subcortical level, activations were found in the left putamen. These results mainly replicate previous PET findings on saccadic control. Second, the interaction between the experimental conditions and their repetition was examined. When activations throughout repetition of the same saccadic task are compared, the supplementary eye fields show a progressive increase of activation. On the contrary, the activation in the cerebellum, left superior parietal lobule and left occipital cortex progressively decreases during the scanning session. Given the existence of such an interaction, the pattern of activations must be interpreted as a function of task repetition. This may be a factor explaining some apparent mismatch between different studies.

[Perioperative antibiotic prophylaxis in orthodontic bone operations of the facial skull]

Intraoral orthognathic surgical procedures are clean-contaminated operations because of the facultative pathogenic flora of the oral cavity. Without antibiotic prophylaxis in this kind of operation a postoperative wound infection can be expected in 20-31% of cases. Therefore, a retrospective analysis of the clinical course of 545 patients with various dentofacial deformities was performed to evaluate the importance of perioperative antibiotic prophylaxis. The total rate of wound infections was 2.8% and lower than rates published in other comparable studies without antibiotic prophylaxis. The rate of wound infection after single mandibular osteotomy (4.1%) was significantly higher than the analogous amount after single maxillary osteotomy (0.8%) because of the mechanical strain of the surgical wound in the region of the mandibular angle and because of the high retention of food particles and other decay products in this area. The recognized rise in the wound infection rate by increasing the length of operation demonstrates that the extent of bacterial contamination of the surgical wound depends on the dimension and duration of surgery. Bacterial flora caused the noticed wound infections in 61.5% of cases aerobic-anaerobic mixed infections, which is in accordance with the results of similar publications. With increasing length of antibiotic prophylaxis, an increase in the incidence of antibiotic-associated side effects and in the wound infection rate could be observed. Therefore, an antibiotic prophylaxis which exceeds 3 days does not seem to be useful. In this study, in which cephalosporins were mostly used, the total rate of antibiotic-associated side effects (4.6%) was lower than analogous amounts of other groups of antibiotics. The analysis demonstrates that a short-term prophylaxis with broad-spectrum cephalosporins such as cefatoxime of 48 h is very effective and useful.