SELECTED ASPECTS OF PENICILLIN ALLERGY

SUMMARY.— Skin tests for immediate hypersensitivity with penicillin derivatives and haemagglutination tests for penicilloyl-specific IgG and IgM antibodies are useful in the prevention, diagnosis and management of clinical adverse reactions mediated by IgE antibodies. In rare instances, the skin tests themselves may cause clinical adverse reactions. Under suitable conditions, hyposensitization or temporary loss of skin sensitivity can be successfully brought about, even in individuals with a high degree of immediate hypersensitivity.
Delayed hypersensitivity plays a role in mediating certain non-urticarial forms of penicillin allergy, including some cases of exanthematous eruptions. The degree of delayed hypersensitivity consistently fluctuates to lower levels after administration of therapeutic doses of penicillin.
Preliminary data are presented which suggest that infants who are given penicillin at birth form IgM penicilloyl-specific serum antibodies much less frequently and in lower titres than occur after penicillin therapy later in life.     

STRATEGIES FOR RECONSTRUCTION AFTER UNSUCCESSFUL OR UNSATISFACTORY PRIMARY TREATMENT OF PATIENTS WITH BLADDER EXSTROPHY OR INCONTINENT EPISPADIAS

PURPOSE: Following unsuccessful or unsatisfactory primary treatment in patients with the epispadias/exstrophy complex, the options for a surgical solution to preserve the upper urinary tract, to achieve complete continence, and to reconstruct the external and female internal genitalia are limited. We reviewed the records of the patients treated at our institution to determine a surgical compromise between ingenious operative constructions and patient desires, both of which are secondary to stabilization of renal function. MATERIALS AND METHODS: From 1967 to December 1997, 128 patients with bladder exstrophy/epispadias complex were treated, of 80 whom had received previous unsuccessful or unsatisfactory treatment. Of these patients 72 were followed for an average of 22.4 years after the first surgical intervention. There were 40 patients referred to our institution after primary bladder closure and bladder neck reconstruction, 10 after rectal bladder, 7 after ureterosigmoidostomy and 5 after incontinent diversion. RESULTS: At the latest followup 19 patients had a rectal reservoir, 38 an ileocecal pouch, 12 a conduit diversion and 3 an augmented Young-Dees procedure. The upper urinary tract remained stable in 95% of the renal units with rectal reservoir, 95% with ileocecal pouch, 96% with a colonic conduit and 100% with an augmented Young-Dees procedure. Day and night continence was achieved in 95% of the patients with a rectal reservoir and 97% of those with an ileocecal pouch were continent, whereas only 2 of the 3 patients with an augmented Young-Dees procedure were continent. Of the women 16 were satisfied with the cosmetic results and 6 delivered 8 children by cesarean section. Only 1 man was dissatisfied with the final cosmetic result. All adults but 1 engaged in sexual intercourse. CONCLUSIONS: The first operative intervention in patients with bladder exstrophy/epispadias complex determines their fate. After failure of primary treatment, the upper urinary tract must be stabilized. In patients with severely impaired renal function the colonic conduit is our method of choice while in those with a normal or slightly dilated upper urinary tract and intact anal sphincter we performed a rectal reservoir. In the remaining patients an ileocecal pouch guarantees continence day and night. The results of genital reconstruction are satisfactory.     

Murine tumour necrosis factor plays a protective role during the initial phase of the experimental infection with Trypanosoma brucei brucei

Soluble extracts from salivarian trypanosomes (Trypanosoma brucei brucei, T. evansi and T. congolense) were shown to be capable of inducing murine tumour necrosis factor (mTNF) secretion, both in vivo and in vitro, whereas the soluble extract of an intracellular trypanosome (T. cruzi) failed to do so. Furthermore, the role of mTNF during the initial phase of experimental infections with T. brucei was studied by treating infected mice with mTNF-inducing trypanosoma soluble extract and with neutralizing monoclonal anti-mTNF antibodies. Treatment of the infected animals with different doses of T. brucei soluble extract resulted in a lower first parasitaemia peak (low lysate dose) and in a longer survival time or in a nearly total inhibition of parasite development (high lysate dose). Cotreatment of the infected mice with both anti-mTNF antibodies and a high dose of soluble extract completely restored the parasite development in both trypanosusceptible C3H/He mice and trypanosubtolerant CBA/Ca mice, indicating a protective role of mTNF during the parasitaemia. Collectively these results suggest a negative influence of mTNF on T. brucei development in vivo.     

A New Mechanical Sensor for Detecting Body Activity and Posture, Suitable for Rate Responsive Pacing

In the past, thought about rate responsive pacing mainly focused on rate increase with exercise but did not consider that a rate increase with postural changes also is mandatory in order to prevent orthostatic reactions. A nightly decrease in pacemaker rate when the body is at rest and in a supine position is a further advantage for the patient's sleep and recovery. Therefore, we developed a sensor that could detect not only rest and body activity but also discriminate between a supine and an upright position. This sensor is a muiticontact tilt switch containing a small mercury ball, as shown in the left panel of the figure below. The principle of discrimination between rest and low and high body activity is realized by the movement of the mercury ball resulting from body motion, which causes openings and closures within the sensor as the ball touches the numerous sensor contacts. In the upright position, a distinct number of contacts at the bottom of the tilt switch are closed. In the supine position, there is no closure of the bottom contacts and a postural discrimination can he achieved. We studied 12 volunteers and 10 pacemaker patients with this new device both at rest and during physical exercise. The right panel of the figure illustrates that the contacts per second correlate to the increase of physical exercise, such as walking on the treadmill. Further studies with an external pacemaker containing a small sensor suitable to fit into the pacemaker are in preparation.     

A New Rate-Modulated Pacemaker System Optimized by Combination of Two Sensors

A new rate-modulated pacemaker system optimized by combination of two sensors is described. The parameter body activity and central venous blood temperature control the pacemaker rate. The specific characteristic of each parameter determines its role within the algorithm. While the motion sensor yields a fast reaction following the onset or a change of stress intensity, central venous blood temperature corresponds better to body metabolism. An indication of increased exercise from the motion sensor results in an accordingly rapid increase in the pacing rate. Unless this increased exercise is confirmed by an increase in central venous blood temperature within 2 or 3 minutes, the new motion level will be assumed to be the new baseline motion value and the pace rate will return to a basic pacing rate. Prolonged inappropriate responses are therefore avoided. Longer lasting exercise, fever and nonphysiological signals are recognized and handled safely. Exercise tests with five volunteers under various conditions showed pacing rate behavior that was close to normal.