Guido A. Schoenenberger

The present status of research in burn toxins

Modern intensive care combined with current improvements in the specific, systemic and local therapy of burns has delayed the mortal effects of severe burns. Nor has there been any significant improvement in this mortality during the last decade.The occurrence of uncontrollable infection and sepsis due to gram-negative bacteria or fungi as the basic cause of death was not a satisfactory explanation. So, progress should only be expected from a new concept in burn treatment. This new concept should be to view the burn disease as being caused by toxic factors induced by thermal injury to the skin. Electron-microscope studies in mice and rats have revealed similar mitochondrial alterations in hepatocytes after either a sublethal controlled burn injury or an intraperiotoneal application of an equivalent dose, of a cutaneous burn toxin. The intraperitoneal injection of different amounts of the burn toxin indicated, that the extent of the mitochondrial changes correlated directly with the dose of toxin. Investigations of liver metabolism suggested an inhibition of the oxygenation chain. The incubation of isolated liver cells together with the burn toxin demonstrated by scanning electron microscopy a direct cytotoxic effect of the burn toxin. In animal tests the pathogenic effect of the burn toxin could be prevented by treatment with an antitoxic IgG generated in sheep.The fatal sepsis of severely burned patients is the consequence of a decreased host defence against infections, which is caused by a primary and general toxic alteration of the whole organism. One important aspect of treatment should therefore be the elimination of burn toxins. To achieve this management should include primary excision of the burns, local application of nonabsorbable protein-complex-binding substances and specific passive immuno-therapy with an antitoxic IgG.

Effects of DSIP in man. Multifunctional psychophysiological properties besides induction of natural sleep

Animal experiments confirmed the neuropeptide nature of delta-sleep-inducing-peptide (DSIP) and a species-specific sleep promotion. Five different human studies were carried out with single and repeated intravenous injections of DSIP under double-blind conditions, and with assessing treatment effects by psychophysiological tests and polygraphic recordings. Compatibility of DSIP was good. Slow injection proved essential. A latency of sleep induction of 1 h, but a duration of up to 20 h was found. The somnogenic properties, initially proven in animal studies, were confirmed. Indications of specific effects on chronobiological regulations were found. A complete normalization of disturbed sleep was achieved by four consecutive injections to insomniacs. During the active awake state, DSIP induced higher alertness and better performance. Psychological tests and evaluation by psychotherapists indicated modulation of ego functions by DSIP in the direction of improved stress tolerance and coping ability. The various actions of DSIP might be conceptualized neurophysiologically on the level of programming behavior by means of changing local vigilances. Whereas the somnogenic actions of DSIP appear promising for treating insomnia, other therapeutic perspectives in the field of psychiatry have to be explored.

Survival in major burn injuries treated by one bathing in cerium nitrate

Sixty-four patients aged 16-74 years with total body surface area burns (TBSA) ranging from 30 to 90 per cent, were given one bathing in 0.04 M cerium nitrate within 4 h of admission to hospital. Of 21 patients aged 16-30 years, one died (aged 28 with 90 per cent TBSA), and of those aged 31-74 years, two died, one (aged 50 years with 55 per cent TBSA) had multiple internal injuries, the other (aged 51 years with 55 per cent TBSA) had a pulmonary embolism at day 19. Two risk scores, developed from data on 11,200 burn patients treated by standard methods (Roi et al. 1983), were applied to the analysis of risk for 59 patients for whom both total burn surface (TB) and full thickness (FT) areas had been recorded. About 20 patients bore risk of 0.8 or greater on the FT scale and 1.0 on the TB scale, yet instead of 80 per cent deaths among these, only two died. No FT assessment had been made on the multiple injury death whose TB risk score was 0.66. Such survival results in high-risk patients should encourage the use of cerium nitrate for treating serious burn injury.

Effects of repeated DSIP and DSIP-P administration on the circadian locomotor activity of rats

Daily intravenous evening injections of 30 nmol/kg DSIP (Delta Sleep-Inducing Peptide) in rats adapted to a constant 24 hr light:dark cycle produced changes in the circadian locomotor behavior. After 3 days the normally high locomotor activity during the dark phase was reduced while during the light (sleeping) phase the animals became relatively more active. Similar, but more rapid and more marked changes were observed (with the same schedule of injections) after 0.1 nmol/kg DSIP-P (the analogue of DSIP phosphorylated at the serine in position 7). In fact the peptide and its analogue induced a relative reversal or shift of the circadian locomotor activity phases opposite to the persisting light:dark conditions (=Zeitgeber). This suggests that DSIP exerts rather complex programming effects on the circadian activities and has more than just a sleep-inducing activity.

Influence of burn-induced lipid-protein complex on IL2 secretion by PBMC in vitro

Normal peripheral blood mononuclear cells (PBMC) were incubated with the lectins PHA and ConA to stimulate IL2 release into the culture supernatants. In the added presence of the lipid-protein complex (LPC) derived from burned skin, PHA and ConA produced much less bioavailable IL2, the combination with PHA being more inhibitory of its production than that with ConA at concentrations of 1 microgram and 5 micrograms lectin/ml. As LPC alone also elicited IL2 production the inhibition of active IL2 production with these lectins was seen as a synergistic reaction with LPC. This was not altered by incubating cells with PHA alone, followed later by LPC, suggesting that LPC affects later molecular events which develop in T-cell activation. However, after incubating LPC first and washing it from the cells, both lectins were able to stimulate secretion of higher levels of bioavailable IL2, but again, less IL2 was produced with PHA than with ConA. Since PHA and ConA are reported to react with the T-cell receptor (TCR) and CD3 T-cell surface antigens, respectively, although both react additionally with CD2, it appears that LPC interfered more directly with TCR-related reactions than those involving CD3, although the two antigens have been considered to be interdependent. LPC is a trimer of a complex of six proteins from skin cell membranes, which had coalesced under the influence of thermal energy. The six proteins have relative molecular weights of 40, 50, 65, 110, 120 and 160 kDa. By coincidence 40 kDa and 51 kDa are the weights of the heterodimer subunits of TCR alpha/beta, and CD2 is 50 kDa.(ABSTRACT TRUNCATED AT 250 WORDS)

Pathophysiologische Untersuchungen an einem Verbrennungsmodell der Maus

Summary1.A new technique to apply high temperature burns and scalds under controlled conditions in living mice has been established.2.The difference between scalds and high temperature heat injuries with respect to the histological changes, the temperature profile within the skin and the mortality rate has been demonstrated. A mechanism for toxin formation shown to occurin vitro in mammalian skin under standardized energy application was reproducedin vivo.3.The toxic effect of the isolated product and the lethal burn injury(in vivo) upon kidney function measured by serum creatinine and urea has been shown.4.The relationship between the surface area injured and the animals body weight and total surface as a critical parameter with respect to the survival chance has been established.Zusammenfassung1.Es wurde ein neues Verbrennungsmodell der Maus entwickelt, das es erlaubt, Verbrennungen und Verbrühungen unter kontrollierten Bedingungen am lebenden Tier vorzunehmen.2.Der Unterschied zwischen Verbrennung und Verbrühung in bezug auf die Mortalität, den Temperaturverlauf in der Haut und die histologischen Unterschiede konnte gezeigt werden. Der mechanismus für eine Toxinbildung bei der Verbrennung wurde bewiesen.3.Der Einfluß des isolierten Toxins und der letalen Verbrennung auf die Nierenfunktion wurde an Veränderungen der Kreatinin- und Harnstoffwerte im Serum nachgewiesen.4.Das Größenverhältnis der durch thermische Energie geschädigten Haut zum Körpergewicht und der Oberfläche zeigte sich als kritischer Parameter der Mortalität.

Increased Survival Rates by Topical Treatment of Burns with Cerium Nitrate

In experiments on mice we were able to show that the negative effects attributed to burn toxins could almost completely be prevented by one single early treatment of the burned skin with a 0.04 M solution of cerium nitrate [Ce(NO3)3]. The survival rate was 10% for animals which were grafted with burned skin. Treatment with Ce(NO3)3 increased the survival rate to 74%. A reflection of this protective effect was the prevention of the burn-induced disturbance of the acceptor control ratio in isolated liver cell mitochondria. Repeated use of Ce(NO3)3 showed adverse effects due to an increased absorption. An effective treatment of burns with Ce(NO3)3 is without problems and can be done in any hospital.

Delta-Sleep-Inducing Peptide and Two of Its Analogs Reduce Nocturnal Increase of N-Acetyltransferase Activity in Rat Pineal Gland

Abstract: Serotonin N‐acetyltransferase, an enzyme of the pineal gland, converts serotonin to N‐acetylserotonin. The activity of this enzyme is induced by norepinephrine in the evening to reach high levels during the dark phase. Delta‐sleep‐inducing peptide, a humoral sleep factor, also seems to affect circadian rhythms. Intravenous injection of this peptide or either of two of its analogs in the evening significantly reduced the increase of N‐acetyltransferase 4 h later. The dose‐response relationship of the peptides showed an inverted U‐shaped pattern with the active dose about 30 nmol/kg. The effect appears to be dependent on the time of day of administration, as injections in the morning did not change the enzymatic activity. These findings indicate that delta‐sleep‐inducing peptide (and two of its analogs) can affect enzymatic activities and that these influences probably vary throughout a time period of 24 h.

DSIP-induced changes of the daily concentrations of brain neurotransmitters and plasma proteins in rats

The influence of delta sleep-inducing peptide (DSIP) on the brain neurotransmitters 5-HT, dopamine and norepinephrine and plasma proteins/corticosterone concentrations for four time points within the 24 hr following IV injection of 30 nmol/kg was investigated in rats. DSIP administered in the morning or in the evening respectively induced changes in nearly all measured parameters. Different effects were observed for different times of administration. The most marked changes were found in the level of serotonin during daytime. In view of the multivariate results obtained by measuring several parameters at multiple time points, a method was developed to describe the time-dependent changes. By means of circadian rhythm statistics based on a statistical likelihood analysis we found that multiple and different changes within the factors daily variation are induced by one injection of DSIP. A multidimensional scaling of the results provides further insights into the correlations of the DSIP-induced effects on plasma and brain factors which are therefore tentatively termed programming functions. These apparently involve not just sleep induction but also act on multiple parameters within the 24 hr rest-activity period.

DSIP/DSIP-P and circadian motor activity of rats under continuous light

Daily intravenous injection of 30 nmol/kg DSIP (delta sleep-inducing peptide) in rats under constant illumination produced marked changes of their motor activity as compared to saline controls. Similar marked but distinctly different effects on the circadian pattern of locomotor behavior partially abolished by constant illumination were also obtained after repeated administration of 0.1 nmol/kg DSIP-P (the phosphorylated analogue of DSIP) which enhanced overall motor activity. In both instances the results additionally differed from those reported for a normal 12 hr light:dark cycle. The present results support the hypothesis that DSIP might primarily act by influencing circadian rhythmicity.