Development of a NanoBRET assay to validate dual inhibitors of Sirt2-mediated lysine deacetylation and defatty-acylation that block prostate cancer cell migration

Sirtuin2 (Sirt2) with its NAD⁺-dependent deacetylase and defatty-acylase activities plays a central role in the regulation of specific cellular functions. Dysregulation of Sirt2 activity has been associated with the pathogenesis of many diseases, thus making Sirt2 a promising target for pharmaceutical intervention. Herein, we present new high affinity Sirt2 selective Sirtuin-Rearranging Ligands (SirReals) that inhibit both Sirt2-dependent deacetylation and defatty-acylation in vitro and in cells. We show that simultaneous inhibition of both Sirt2 activities results in strongly reduced levels of the oncoprotein c-Myc and an inhibition of cancer cell migration. Furthermore, we describe the development of a NanoBRET-based assay for Sirt2, thereby providing a method to study cellular target engagement for Sirt2 in a straightforward and accurately quantifiable manner. Applying this assay, we could confirm cellular Sirt2 binding of our new Sirt2 inhibitors and correlate their anticancer effects with their cellular target engagement.

Sirt2 inhibitors that show simultaneous inhibition of Sirt2 deacetylase and defatty-acylase activity block prostate cancer cell migration and their target engagement is shown by a newly developed NanoBRET assay.

Simultaneous Nitrite/Nitrate Imagery at Millimeter Scale through the Water-Sediment Interface

The present study describes new procedures to obtain at millimeter resolution the spatial distribution of nitrite and nitrate in porewaters, combining diffusive equilibrium in thin films (DET), colorimetry and hyperspectral imagery. Nitrite distribution can be easily achieved by adapting the well-known colorimetric method from Griess (1879) and using a common flatbed scanner with a limit of detection about 1.7 μmol L(-1). Nitrate distribution can be obtained after reduction into nitrite by a vanadium chloride reagent. However, the concentration of vanadium chloride used in this protocol brings coloration with a wide spectral signature that creates interference only deconvolvable by imaging treatment from an entire visible spectrum for each pixel (spectral analysis). This can be achieved by hyperspectral imaging. The protocol retained in the present study allows obtaining a nitrite/nitrate image with micromolar limit of detection. The methods were applied in sediments from the Loire Estuary after different treatments and allowed to precisely describe two-dimensional millimeter features. The present technique adds to the combination of gel-colorimetry and hyperspectral imagery a very promising new application of wide interest for environmental issues in the context of early diagenesis and benthic fluxes.

LSD1 controls metastasis of androgen-independent prostate cancer cells through PXN and LPAR6

Lysine-specific demethylase 1 (LSD1) was shown to control gene expression and cell proliferation of androgen-dependent prostate cancer (PCa) cells, whereas the role of LSD1 in androgen-independent metastatic prostate cancer remains elusive. Here, we show that depletion of LSD1 leads to increased migration and invasion of androgen-independent PCa cells. Transcriptome and cistrome analyses reveal that LSD1 regulates expression of lysophosphatidic acid receptor 6 (LPAR6) and cytoskeletal genes including the focal adhesion adaptor protein paxillin (PXN). Enhanced LPAR6 signalling upon LSD1 depletion promotes migration with concomitant phosphorylation of PXN. In mice LPAR6 overexpression enhances, whereas knockdown of LPAR6 abolishes metastasis of androgen-independent PCa cells. Taken together, we uncover a novel mechanism of how LSD1 controls metastasis and identify LPAR6 as a promising therapeutic target to treat metastatic prostate cancer.

Millimeter-scale alkalinity measurement in marine sediment using DET probes and colorimetric determination

Constrained DET (Diffusive Equilibration in Thin films) probes equipped with 75 sampling layers of agarose gel (DGT Research(©)) were used to sample bottom and pore waters in marine sediment with a 2 mm vertical resolution. After retrieval, each piece of hydrogel, corresponding to 25 μL, was introduced into 1 mL of colorimetric reagent (CR) solution consisting of formic acid and bromophenol blue. After the elution/reaction time, absorbance of the latter mixture was read at 590 nm and compared to a calibration curve obtained with the same protocol applied to mini DET probes soaked in sodium hydrogen carbonate standard solutions. This method allows rapid alkalinity determinations for the small volumes of anoxic pore water entrapped into the gel. The method was assessed on organic-rich coastal marine sediments from Thau lagoon (France). Alkalinity values in the overlying waters were in agreement with data obtained by classical sampling techniques. Pore water data showed a progressive increase of alkalinity in the sediment from 2 to 10 mmol kg(-1), corresponding to anaerobic respiration in organic-rich sediments. Moreover, replicates of high-resolution DET profiles showed important lateral heterogeneity at a decimeter scale. This underlines the importance of high-resolution spatial methods for alkalinity profiling in coastal marine systems.

Characterization of the adrenoleukodystrophy-related (ALDR, ABCD2) gene promoter: inductibility by retinoic acid and forskolin

The adrenoleukodystrophy-related gene (ALDR, ABCD2) is a candidate modifier gene and a potential therapeutic target for X-linked adrenoleukodystrophy (ALD), a severe neurodegenerative disease. The ALDR gene is the closest homologue of the ALD gene, which encodes a peroxisomal ABC transporter involved in the catabolism of very-long-chain fatty acids. Administration of fenofibrate upregulates ALDR expression in rodent liver. As a step toward understanding ALDR transcriptional regulation, the mouse and human 5' regions were characterized. The human and mouse genes share a 500-bp conserved region that contains potential Sp1- and AP-2-binding sites but no TATA box. Analysis of the 5'-flanking region of ALDR using a luciferase reporter system revealed that 1.3 kb of human or mouse 5'-upstream region has functional promoter activity. In these transfection experiments, promoter activity of both human and mouse genes could be upregulated by 9-cis-retinoic acid and forskolin, while no effect of PPARalpha could be detected.

FHL2, a novel tissue-specific coactivator of the androgen receptor

The control of target gene expression by nuclear receptors requires the recruitment of multiple cofactors. However, the exact mechanisms by which nuclear receptor-cofactor interactions result in tissue-specific gene regulation are unclear. Here we characterize a novel tissue-specific coactivator for the androgen receptor (AR), which is identical to a previously reported protein FHL2/DRAL with unknown function. In the adult, FHL2 is expressed in the myocardium of the heart and in the epithelial cells of the prostate, where it colocalizes with the AR in the nucleus. FHL2 contains a strong, autonomous transactivation function and binds specifically to the AR in vitro and in vivo. In an agonist- and AF-2-dependent manner FHL2 selectively increases the transcriptional activity of the AR, but not that of any other nuclear receptor. In addition, the transcription of the prostate-specific AR target gene probasin is coactivated by FHL2. Taken together, our data demonstrate that FHL2 is the first LIM-only coactivator of the AR with a unique tissue-specific expression pattern.

Role of nitric oxide in pancreatic tumour growth: in vivo and in vitro studies

Nitric oxide (NO), an endogenous free radical, has been implicated in a wide range of biological functions. NO is generated enzymatically from the terminal guanidinonitrogen of L-arginine by nitric oxide synthase (NOS). Despite intensive investigations, the role of NO--either as the primary product of the L-arginine/NOS pathway or provided from the NO donor sodium nitroprusside (SNP)--in carcinogenesis and tumour cell growth remains unclear and controversial. The objective of this study was to examine the growth effects of NO on a ductal pancreatic adenocarcinoma in the rat and on a human pancreatic tumour cell line (HA-hpc2). In vivo, both SNP and endogenous induction of NO by endotoxins [lipopolysaccharide (LPS)] plus L-arginine significantly reduced the tumour growth. To investigate the mechanisms of NO anti-tumour growth action, the effects of either the SNP or L-arginine/NOS pathway were analysed on the HA-hpc2 cell line. Nitrite/nitrate production, NOS activity and iNOS expression [assessed by reverse transcription-polymerase chain reaction (RT-PCR)] were tested and related to growth (assessed by [3H]thymidine incorporation assay) and apoptosis (assessed by internucleosomal DNA cleavage). SNP exerted a dual effect on tumour cells: stimulation of the proliferation up to 1 mM and inhibition at higher concentrations. These effects were related to NO production. Both proliferative and cytostatic responses were inhibited by NO scavenger 2-phenyl-4,4,5,5-tetramethyl-hemidazoline-1-oxyl3-oxide (carboxy-PTIO). The marked apoptotic DNA fragmentation induced by SNP was also abolished by PTIO association. Unlike macrophages, the human pancreatic tumour cells did not seem to express intrinsically the L-arginine/NOS pathway. Macrophages were activated by HA-hpc2 cells as well as by LPS plus cytokines [interleukin (IL)-1beta plus tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma]. In HA-hpc2/macrophage co-cultures, NOS activity and inducible NOS (iNOS) transcription were stimulated, whereas an antiproliferative response was observed. These effects were related to both macrophage amount and NO production. Addition of LPS plus cytokines to co-cultures doubled iNOS activity, nitrite/nitrate production and tumoricidal effect. These data suggest the involvement of NO in pancreatic tumour growth and support the fact that generation of high levels of NO with potential production of endogenous reactive nitrogen intermediates may contribute to induction of apoptosis and tumour growth inhibition.

Research update on serotonin function in bulimia nervosa and anorexia nervosa

The extent to which dysregulation of serotonin function in the central nervous system may contribute to core symptoms in patients with bulimia nervosa and anorexia nervosa is currently an area of intensive psychobiological investigation. Preclinical and clinical studies have demonstrated the involvement of the neurotransmitter serotonin in the regulation of food intake, suggesting that impaired serotonin-mediated satiety signals could contribute to patterns of recurrent binge eating. Other symptom patterns in patients with eating disorders, including mood dysregulation, impulsivity, and obsessionality, as well as therapeutic response to serotonergic agents, suggest involvement of serotonergic pathways. With a primary focus on serotonin function, this article reviews clinical studies of neuroendocrine and behavioral response to pharmacological challenges, levels of neurotransmitter metabolite in cerebrospinal fluid, and platelet studies. Controlled clinical trials involving pharmacological treatment with serotonergic medications are summarized. Considerations for future research are discussed.

Mirror expression of adrenoleukodystrophy and adrenoleukodystrophy related genes in mouse tissues and human cell lines

The adrenoleukodystrophy and adrenoleukodystrophy related proteins belong to a new family of half ATP-binding cassette transporters which are localized within the peroxisomal membrane and whose functions are still unknown. They could possibly homo- or heterodimerize resulting in transporters with similar or distinct functions. The expression of adrenoleukodystrophy and adrenoleukodystrophy related genes was studied at the mRNA and protein levels in adult mouse tissues and several human cell lines. We found that adrenoleukodystrophy and adrenoleukodystrophy related genes have strikingly different expression in most mouse tissues and human cell lines analyzed, indicating that adrenoleukodystrophy and adrenoleukodystrophy related proteins do not function as obligatory partners but might rather fulfill similar metabolic functions in different tissues.

Prolongation of the corrected QT and torsades de pointes cardiac arrhythmia associated with intravenous haloperidol in the medically ill

Consultation psychiatrists are frequently called upon by their medical and surgical colleagues to assist in the management of agitated, delirious patients in the intensive care unit. Intravenous haloperidol has a reputation for safe and effective sedation of these patients and has been found to be free of many of the dangerous anticholinergic and cardiac side effects of the lower-potency neuroleptics. The authors report the cases of three patients who developed torsades de pointes arrhythmia or lengthening of the Q-T interval during treatment with intravenous haloperidol. The cases suggest that the use of intravenous haloperidol should be accompanied by cardiac monitoring and that risk factors for torsades de pointes during haloperidol treatment may include dilated cardiomyopathy and a history of alcohol abuse.

Genetic and phenotypic parameters for type and production in Guernsey dairy cows

Heritabilities; genetic and phenotypic correlations for milk, fat, and protein production; and linear type traits were estimated from a sire model including sire relationships using multiple-trait REML. For the milk production traits, 68,109 first parity records were analyzed. Heritabilities ranged from .31 to .37, genetic correlations between the milk production traits ranged from .80 to .92, and phenotypic correlations ranged from .86 to .94. Linear type traits from 12,996 cows on 15 traits were used to estimate heritabilities and genetic and phenotypic correlations between linear type traits. The heritabilities ranged from .53 for stature to .09 for foot angle. Rear udder height and rear udder width had the highest positive genetic correlation (.85), whereas dairy form and udder depth had the highest negative genetic correlation (-.41). When the first parity production records were merged with type records for cows, 9867 records on 18 traits were obtained. Dairy form, rear udder height, and rear udder width had strong to moderate positive genetic correlations with the three production traits. Fore udder attachment and udder depth had moderate negative genetic correlations with the three milk production traits. These results suggest that selection for improvement of milk production will lead to correlated increases in dairy form, rear udder height, rear udder width, and udder depth and to correlated decreases in the strength of fore udder attachment.

Activities in the placenta and fetal membranes of enzymes involved in energy metabolism

The placenta and the fetal membranes differ in their energy dependent functions and in their blood supply. In a search for quantitative differences in the expression of enzymes involved in energy metabolism in these tissues we measured in the placenta and in amnion and chorion the activities of enzymes involved in carbohydrate metabolism (hexokinase, phosphofructokinase, lactate dehydrogenase, glycogen phosphorylase), a tricarboxylic acid cycle enzyme (succinate dehydrogenase) and an enzyme involved in fatty acid oxidation (hydroxyacyl-CoA-dehydrogenase). The activities of succinate dehydrogenase and hydroxyacyl-CoA-dehydrogenase in the placenta were higher than those in the membranes, whereas the activities of the other enzymes assayed were lower. Lactate dehydrogenase activity was higher in the amnion than in the chorion (p less than 0.01). These results could indicate that the fetal membranes depend mainly on glycolysis for an energy supply.

IgG antibody to purified protein derivative by enzyme-linked immunosorbent assay in the diagnosis of pulmonary tuberculosis

We studied the diagnostic utility of an enzyme-linked immunosorbent assay (ELISA) in hospitalized patients with suspected pulmonary tuberculosis (TB). A positive culture for M. tuberculosis identified active disease, and 3 negative cultures and smears defined the negative group. IgG antibody activity was determined by adding a 1:1,000 dilution of serum to plates coated with PPD antigen. Alkaline phosphatase labeled anti-IgG was added, color developed, and an optical density index (ODI) was determined. Twenty-one patients with M. tuberculosis TB had a mean ODI of 0.27, which was higher than 99 patients without TB, ODI 0.10 (p less than 0.001). An ODI of 0.15 or greater was established as a positive ELISA test. For patients with M. tuberculosis TB, the ELISA had a sensitivity of 67 and a specificity of 79%. The first smear had a sensitivity of 57 and a specificity of 99%. With the first smear and the ELISA test results, a combined sensitivity of 86% was achieved. When both ELISA and the first smear were negative (101 cases), active TB caused by M. tuberculosis was found in only three patients (3.0%).

Temporal relationships between hormonal concentrations and the electrical resistance of the vaginal tract of blue foxes (Alopex lagopus) at pro-oestrus and oestrus

During pro-oestrus, baseline LH concentrations for 9 vixens (pooled data) ranged from 0.8 to 5.3 ng/ml. In each vixen, baseline levels were interrupted by elevations of LH ranging from 3.1 to 10.4 ng/ml. A major preovulatory LH surge was detected in all the vixens. The LH peak ranged from 13.5 to 73.0 ng/ml with an average of 27.8 +/- 18.8 (s.d.) ng/ml. Plasma LH concentrations declined to a basal level of 1.3 +/- 1.0 ng/ml within 48 h of the peak value. The duration of the LH surge was 1-3 days. The LH peak occurred 1 or 2 days before any sexual receptivity was observed. All the vixens were mated twice 2-5 days after the LH peak; 8 conceived. Plasma concentrations of oestradiol-17 beta increased gradually during the last 6-7 days before oestrus and reached maximum values (124-373 pg/ml) at the time of the preovulatory LH peak. The first significant increase in plasma progesterone concentration occurred simultaneously with the LH peak. During oestrus (normally 3-5 days), progesterone levels rose steeply, attaining a mean concentration of 57.0 +/- 17.5 ng/ml when the vixens went out of heat. Androstenedione and testosterone values changed similarly, both increasing at the beginning of pro-oestrus and reaching maximum values (805-1879 pg/ml and 328-501 pg/ml respectively) 1 day before to 1 day after the oestradiol-17 beta peak. The electrical resistance of the vaginal tract increased rapidly during the last 2-3 days of pro-oestrus, reaching a maximum value (300-640 omega) approximately 2 days after the oestradiol-17 beta peak that corresponded with the onset of sexual receptivity. Towards the end of oestrus, the values fell to 100-200 omega.

Bacteremic pneumonia due to gram-negative bacilli

Bacteremic pneumonia due to aerobic gram-negative bacilli was diagnosed in 27 patients during a 20-month period. The mortality was high (81.5%) among these elderly patients (mean age, 61.2 years) with serious underlying disease, in spite of amikacin sulfate therapy that was appropriate as determined by susceptibility testing. Bacteremic pneumonia accounted for 14.1% of patients with gram-negative bacteremia but was responsible for 39.4% of the deaths in the total group of 191 patients. The worsened prognosis of patients with pneumonia was unrelated to the species of infecting organisms or the underlying conditions or disease.

Use of an enzyme-linked immunosorbent assay technique in the differential diagnosis of active pulmonary tuberculosis in humans

Sera from patients with active pulmonary tuberculosis and pulmonary diseases frequently mimicking tuberculosis were assayed for immunoglobulin G antibody activity to purified protein derivative (PPD) by an enzyme-linked immunosorbent assay. A method of standardization was developed to limit assay variation. Patients with active pulmonary tuberculosis had a significantly greater mean level of antibody than had patients with atypical tuberculosis (P = 0.005), sarcoidosis (P = 0.0001), histoplasmosis (P = 0.004), blastomycosis (P = 0.008), or cryptococcosis (P = 0.017), patients who had received bacille Calmette-Guérin vaccination (P = 0.003) or who had a history of treated tuberculosis (P = 0.003), and PPD skin test-positive and skin test-negative control subjects (P = 0.001). This technique may have potential use as a rapid diagnostic aid in evaluating patients with suspected active pulmonary tuberculosis.

[Efficacy of protective effect of aminopropylamino-ethylthiophosphate in neutron beam, gamma or X-irradiation of mice (author's transl)]

The efficacy of the radioprotective agent aminopropylamino-ethylthiophosphate (WR 2721) was tested against different kinds of radiation on female NMRI-mice. The animals were divided into 4 groups and were exposed to neutrons as main component, to secondary gamma rays in a tissue-equivalent phantom, to pure gamma rays and to X-rays respectively. The following dose reduction factors have been obtained: 1.05 for neutron-irradiation, 1.33 for gamma irradiation in tissue-equivalent phantom, 1.69 for pure gamma rays and 2.08 for X-rays. The protective agent WR 2721 is apparently more efficient against low LET radiation. The mechanism of protection has been discussed in this respect.

Studies on poxvirus infections in irradiated animals

If rabbits were given total body irradiation and infected wih vaccinia virus (strain Elstree) a severe disease developed with a viraemia lasting up to 12 days. The clearance of the virus from the peripheral blood was severely impaired by x-ray doses above 800 R. The attenuated vaccinia virus strain MV did not turn virulent, if it was injected to irradiated rabbits. With caution it can be assumed that live vaccines, containing attenuated viruses, may be given to immunosuppressed persons. Rats are not susceptible to ectromelia-virus (mouse-poxvirus); overt clinical sympatoms, however, with a mortality of 30 per cent developed in irradiated rats. This proofs that specific poxviruses can be transferred to another species. As the experimental conditions are unnatural, this may occur only rarely in immunosuppressed persons. After intracerebral infection of Balb-C-mice with low doses of vaccinia virus two types of infection were seen: 1. a severe cytocidal infection of leptomeninges, chorioid plexus and vessels; 2. a noncytocidal, latent infection of glial cells and neurons. Several animals developed a picture resembling experimental allergic encephalomyelitis. It seems that irradiation altered the antigenic conditions of the cytoplasmic membranes in non-cytocidally infected cells. The model might explain some processes in the pathogenesis of demylinating diseases.

Bacteremic infection and malnutrition in patients with solid tumors: investigation of host defense mechanisms

Eighty-five patients with solid tumors without neutropenia were studied in order to determine host characteristics associated with bacteremic infection. Twenty patients without neoplastic disease who had bacteremia served as controls. Bacteremia frequently occurred in patients with tumors of the gastrointestinal and urinary tract, who were over 51 years of age, and had evidence of malnutrition. Peripheral blood lymphocyte dysfunction in vitro was commonly noted in infected patients with cancer. Polymorphonuclear leukocyte (PMNL) dysfunction was common in older bacteremic patients with and without cancer. The PMNL abnormality appeared to be cellular, it was not corrected with use of pooled normal serum, and was manifested by poor uptake of the assay organisms.

[The virostatic effect of adenine-arabinoside monophosphate. Experimental findings and preliminary clinical experiences]

Adenine arabinoside (Ara-A), a synthetic nucleoside, is an antiviral agent, which is effective against poxviruses and viruses of the herpes group. The monophosphate (Ara-AMP) has the great advantage of better solubility, compared to the parent compound. Experimental studies show the outstanding effect of Ara-AMP on the encephalitis by vaccinia-virus in white mice. Even after immunesuppression by total body irradiation, the survival rate of the Ara-AMP treated animals was significantly higher compared to the untreated controls. In experimental vaccinia-virus infections in rabbits, who had undergone total body irradiation. Ara-AMP has a favourable influence upon the course of the disease and the prognosis. Some clinical observations in children with immunesuppression, who suffered from generalized zoster of varicella-infections, are reported. Furthermore in cases of viral encephalitis Ara-AMP was successful. Controlled studies of a greater number of patients on the therapeutic value of Ara-AMP in infections with DNS-viruses are needed.

[Treatment of burns]

Because of the unsatisfactory results hitherto achieved in the bactericidal and bacteriostatic local therapy of burns, Betaisodona ointment was tested and, in view of its good effect, put to further therapeutic use. The advantages of the preparation, apart from the good local tolerance and absence of effect on metabolism, are the good bactericidal and tanning effects on the wound eschar. In no case were smearing coats observed; the necrotic skin remained dry and firm. Except in two patients with second degree burns, epithelization was not influenced by clinically visible infection. In third degree burns accumulation of exudate in the zone of demarcation was only observed in two cases. Bacteriological examinations of the wound surface revealed sterility in several cases; in the other patients the bacterial count did not exceed 10(5)/cm2. In view of the comparative tests, this result must be considered very positive. The above trial has, however, not made use of all testing possibilities. In further studies an iodine absorption test for determining the penetration depth as well as a bacterial count in the tissue will be developed. Furthermore the use of Betaisodona solution for instillation in the zone of demarcation will be examined.

[Asepsis and antisepsis in the treatment of burn patients (author's transl)]

Among the main aspects to be considered when treating burns, the problem of infection control remains unsolved. Considerable financial resources are needed to prevent the transmission of organisms. To justify such investments in buildings and antiseptic measures, an extensive epidemiological hospital study was carried out from 1970 to 1974, involving 930 patients, and more than 25,000 wound biopsies as well as 10,000 contact cultures and environmental swabs. Bacteria from the environment of severly burned patients were counted every week. Serotyping was used for a specialized study of Pseudomonas aeruginosa. In 200 patients wound organisms were counted. The most important organisms were: Streptococcaceae (pyogenic streptococci, less frequently faecal and salivary streptococci). Pseudomonadaceae, Enterobacteriaceae, and Micrococcaceae (especially Micrococcus aureus). Povidon iodine, gentamicin and silver sulfadiazine were used for local disinfection. Antibiotics used were gentamicin, carbenicillin and polymyxin. Whereas from 1970 to 1972 P. aeruginosa was the predominant organism found in wounds, other gram-positive organisms increased from 1972 on. Wounds were colonized mainly in the course of the first two weeks of treatment. Special studies regarding P. aeruginosa revealed a predominance of serotypes 5 and 13 between 1970 and 1973, whereas types brought into the hospital were dominant from 1973 on. An analysis of furniture and equipment, water faucets and drains showed that Pseudomonas strains found in the water did not coincide with those found in wounds. Therefore, a contamination from this source seems unlikely. Strains found on furniture and equipment, however, also appeared in the wound flora. When the therapeutic routine was changed (to prevent patients passing through common treatment areas such as bathrooms and dressing areas) hospital organisms 5 and 13 could be eliminated almost completely. Thus, it is possible to achieve a considerable reduction in the rate of cross-infection among patients by, for instance, excluding common treatment areas from the therapy programme. Nevertheless, in the majority of cases wounds will still be colonized, in particular by bacteria that were already in the anal region or on the skin before the patient was injured. For this reason, the elimination of such organisms by topical bactericidal agents constitutes an an important factor in efforts to reduce the rate of septicaemic complications. In view of the persisting high mortality due to generalized infections this therapeutic aspect must also be exploited thoroughly in the future. Although in comparative studies of topical therapy using povidon iodine, silver sulfadiazine and gentamicin, organisms did appear in the course of the first two weeks; in the case of the PVP-I the colonization never reached 10(5) organisms per cm2, i.e. the danger threshold for generalized sepsis. There was no evidence of a correlation between number of organisms and depth of burns.

[Is an active immunization against pseudomonas aeruginosa in burns justifiable?]

The critical evaluation of active immunisation against infection by Pseudomonas aeruginosa in severely burned patients was carried out. Two group,s were tested: 1. 120 burned patients vaccinated, 2. 68 persons as control group vaccinated. In the healthy control group, the vaccination resulted in an almost linear rise of the antibody titer. In contrast thereto, vaccination in patients resulted initially in a raised titer which was followed in the 3rd and 4th week by a sharp fall. Due to the fact that an infected burn wound can also be considered as a vaccination, we examined the antibody titer in a 2nd group of patients which were not vaccinated. Similarly after a short rise there was a definite lowering in the 3rd and 4th week. The research included a total of 239 persons. In order to obtain a polyvalent vaccine, we carried out an epidemiological study involving serotyping of Pseudomonas aeruginosa over a period of several years.