Liquid argon light collection and veto modeling in GERDA Phase II

The ability to detect liquid argon scintillation light from within a densely packed high-purity germanium detector array allowed the Gerda experiment to reach an exceptionally low background rate in the search for neutrinoless double beta decay of76 Ge. Proper modeling of the light propagation throughout the experimental setup, from any origin in the liquid argon volume to its eventual detection by the novel light read-out system, provides insight into the rejection capability and is a necessary ingredient to obtain robust background predictions. In this paper, we present a model of the Gerda liquid argon veto, as obtained by Monte Carlo simulations and constrained by calibration data, and highlight its application for background decomposition.

Characterization of 30 76 Ge enriched Broad Energy Ge detectors for GERDA Phase II

The GERmanium Detector Array (Gerda) is a low background experiment located at the Laboratori Nazionali del Gran Sasso in Italy, which searches for neutrinoless double-beta decay of 76 Ge into 76 Se+2e - . Gerda has been conceived in two phases. Phase II, which started in December 2015, features several novelties including 30 new ⁷⁶Ge enriched detectors. These were manufactured according to the Broad Energy Germanium (BEGe) detector design that has a better background discrimination capability and energy resolution compared to formerly widely-used types. Prior to their installation, the new BEGe detectors were mounted in vacuum cryostats and characterized in detail in the Hades underground laboratory in Belgium. This paper describes the properties and the overall performance of these detectors during operation in vacuum. The characterization campaign provided not only direct input for Gerda Phase II data collection and analyses, but also allowed to study detector phenomena, detector correlations as well as to test the accuracy of pulse shape simulation codes.

Probing Majorana neutrinos with double-β decay

A discovery that neutrinos are Majorana fermions would have profound implications for particle physics and cosmology. The Majorana character of neutrinos would make possible the neutrinoless double-β (0νββ) decay, a matter-creating process without the balancing emission of antimatter. The GERDA Collaboration searches for the 0νββ decay of ⁷⁶Ge by operating bare germanium detectors in an active liquid argon shield. With a total exposure of 82.4 kg⋅year, we observe no signal and derive a lower half-life limit of T _1/2 > 0.9 × 10²⁶ years (90% C.L.). Our T _1/2 sensitivity, assuming no signal, is 1.1 × 10²⁶ years. Combining the latter with those from other 0νββ decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 to 0.16 electron volts.

Improved Limit on Neutrinoless Double-β Decay of ^{76}Ge from GERDA Phase II

The GERDA experiment searches for the lepton-number-violating neutrinoless double-β decay of ^{76}Ge (^{76}Ge→^{76}Se+2e^{-}) operating bare Ge diodes with an enriched ^{76}Ge fraction in liquid argon. The exposure for broad-energy germanium type (BEGe) detectors is increased threefold with respect to our previous data release. The BEGe detectors feature an excellent background suppression from the analysis of the time profile of the detector signals. In the analysis window a background level of 1.0_{-0.4}^{+0.6}×10^{-3}  counts/(keV kg yr) has been achieved; if normalized to the energy resolution this is the lowest ever achieved in any 0νββ experiment. No signal is observed and a new 90% C.L. lower limit for the half-life of 8.0×10^{25}  yr is placed when combining with our previous data. The expected median sensitivity assuming no signal is 5.8×10^{25}  yr.

Ellipsometry with polarisation analysis at cryogenic temperatures inside a vacuum chamber

In this paper we describe a new variant of null ellipsometry to determine thicknesses and optical properties of thin films on a substrate at cryogenic temperatures. In the PCSA arrangement of ellipsometry the polarizer and the compensator are placed before the substrate and the analyzer after it. Usually, in the null ellipsometry the polarizer and the analyzer are rotated to find the searched minimum in intensity. In our variant we rotate the polarizer and the compensator instead, both being placed in the incoming beam before the substrate. Therefore the polarisation analysis of the reflected beam can be realized by an analyzer at fixed orientation. We developed this method for investigations of thin cryogenic films inside a vacuum chamber where the analyzer and detector had to be placed inside the cold shield at a temperature of T ≈ 90 K close to the substrate. All other optical components were installed at the incoming beam line outside the vacuum chamber, including all components which need to be rotated during the measurements. Our null ellipsometry variant has been tested with condensed krypton films on a highly oriented pyrolytic graphite substrate (HOPG) at a temperature of T ≈ 25 K. We show that it is possible to determine the indices of refraction of condensed krypton and of the HOPG substrate as well as thickness of krypton films with reasonable accuracy.

Results on neutrinoless double-β decay of 76Ge from phase I of the GERDA experiment

Neutrinoless double beta decay is a process that violates lepton number conservation. It is predicted to occur in extensions of the standard model of particle physics. This Letter reports the results from phase I of the Germanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory (Italy) searching for neutrinoless double beta decay of the isotope (76)Ge. Data considered in the present analysis have been collected between November 2011 and May 2013 with a total exposure of 21.6 kg yr. A blind analysis is performed. The background index is about 1 × 10(-2) counts/(keV kg yr) after pulse shape discrimination. No signal is observed and a lower limit is derived for the half-life of neutrinoless double beta decay of (76)Ge, T(1/2)(0ν) >2.1 × 10(25) yr (90% C.L.). The combination with the results from the previous experiments with (76)Ge yields T(1/2)(0ν)>3.0 × 10(25) yr (90% C.L.).

Influenza vaccination in the elderly

Influenza vaccination of elderly people has been shown to be useful. All vaccine types are well tolerated by higher age group vaccinees. Actually, whole virus vaccine, split virus vaccine and subunit vaccine are used in the vaccination of the elderly. Some studies have suggested that the induction of serum influenza antibody production was reduced in elderly persons when compared with that elicited in younger persons. However, investigations on the protective efficacy of influenza vaccination in the elderly have demonstrated a clinical protection of > or = 50% for preventing hospitalization. Live attenuated influenza vaccine conferred protection similar to that obtained with a conventional subunit vaccine. A virosomal unilamellar trivalent hemagglutinin vaccine showed promising serological results compared with those obtained with a whole cell vaccine and with a subunit vaccine, respectively. The actual policy is to vaccinate persons > or = 65 years of age and the groups that can transmit influenza to them. Each year's vaccine should contain three virus strains representing the influenza viruses that are likely to circulate in the upcoming winter.

[Immunogenicity and stability of an aluminum-free liposomal hepatitis A vaccine (Epaxal Berna)]

The high immunogenicity of the liposomal hepatitis A vaccine (Epaxal Berna) after a single dose and after a booster dose one year later has been confirmed in several studies with healthy adult volunteers: 95-100% and 96-100% seroconversion (> or = 20 mIE/ml) after 1 and 12 months respectively, as well as a booster effect in 100% of the cases after revaccination. The tolerability of this new, alum-free vaccine has been excellent with 6-25% local and 0-13% mild systemic reactions after a dose of 0.5 ml. Stability testing with and without detergent indicated partial internalization of the hepatitis A virions in the phospholipid bilayer of the liposome vesicles with storage. Immunization of 10 healthy adult volunteers with vaccine stored for 32 months at 4 degrees C showed, however, that the duration of storage has no influence on immunogenicity and tolerability of the vaccine.

[Radiologic and ultrasound detection of gallstones]

Ultrasonography (US) is the method of choice for evaluation of gallbladder stones with an accuracy of 96%. Number, size and calcification can be assessed by virtue of US reflection and attenuation. If more than five stones are present, the accuracy decreases. To determine the calcium content of stones more precisely, computed tomography can be used. This allows an assessment of the success rate of lithotripsy and chemolysis. Oral cholecystography is an alternative method of similar accuracy as US. It provides additional information about the patency of the cystic duct. In the presence of ductal stones, the accuracy of US decreases to 30%, mainly because of overlying bowel gas. Since 8 to 16% of all cases of cholecystolithiasis are accompanied by choledocholithiasis and since this entails a change in treatment, intravenous cholecystocholangiography with an accuracy of more than 90% is the method of choice in this case. Additionally, it provides knowledge on the biliary anatomy preoperatively. It does not, however, replace US, because opacification of the gallbladder is limited with this method. If intravenous cholecystocholangiography fails in case of impaired liver function, transcholecystic cholangiography or, in cases of dilated ducts, percutaneous transhepatic cholangiography can be used. Plain film radiography is not a suitable technique, since only 10 to 15% of all gallstones calcify.

[Spontaneous rupture of the left hepatic duct]

A previously well 24-year-old man complained of persistent epigastric pain after a session of intensive muscle building exercise especially of the abdominal muscles. The abdomen was diffusely tender without guarding. There was an increased concentration of bilirubin (64.7 mumol/l), GOT (117 U/l), GPT (529 U/l) and alkaline phosphatase (150 U/l). Ultrasound examination showed a widening of the choledochal duct to 11 mm without signs of gallstones. Endoscopic retrograde cholangiography additionally revealed contrast-medium extravasation from the left hepatic duct. Computed tomography, performed immediately afterwards, confirmed the extravasation, while liver and pancreas were unremarkable. Laparoscopy revealed a 5 mm tear in the left hepatic duct, close to the hepatic duct bifurcation with bile effusion into the peritoneal cavity. The latter was rinsed endoscopically with Ringer's solution and drains were placed in the omental bursa and subhepatically in the region of the bile leak. To relax the sphincter Oddi glycerol trinitrate was administered postoperatively, for the first five days 72 mg/24 h intravenously, then for nine days twice daily 20 mg by month. No more bile drained as early as the second postoperative day and the patient was free of symptoms 2 weeks later.

Safety and immunogenicity of Escherichia coli O18 O-specific polysaccharide (O-PS)-toxin A and O-PS-cholera toxin conjugate vaccines in humans

O-specific polysaccharide (O-PS) isolated from serotype 18 Escherichia coli lipopolysaccharide (LPS) was covalently coupled to either Pseudomonas aeruginosa toxin A (TA) or or cholera toxin (CT). The conjugates were nontoxic and nonpyrogenic. The conjugates were well tolerated on parenteral administration to human volunteers, with only mild, transient local reactions reported. Immunization engendered an IgG antibody response to both the O-PS and carrier protein. Anti-LPS antibody promoted the uptake and killing of an E. coli O18 strain bearing the K1 capsule by human polymorphonuclear leukocytes, which was complement dependent. Antibody to carrier protein neutralized the activity of native TA or CT in cell culture assays. Passively transferred IgG isolated from the serum of immunized donors provided a significant (P less than .01) degree of protection against fatal experimental E. coli O18 sepsis in mice. This study illustrates the potential use of such conjugates as vaccines against E. coli extraintestinal infections.

Safety and immunogenicity of a Pseudomonas aeruginosa O-polysaccharide toxin A conjugate vaccine in humans

Lipid A-free polysaccharide (PS) isolated from Pseudomonas aeruginosa immunotype 5 lipopolysaccharide (LPS) was covalently coupled to toxin A via reductive amination. The PS-toxin A conjugate was comprised of 29.8% PS and 70.2% toxin A, possessed a molecular weight of greater than 1 X 10(6), was nontoxic for animals and was nonpyrogenic for rabbits at a dose of 50 micrograms/kg body wt when administered intravenously. The conjugate evoked only mild, transient reactions upon subcutaneous administration to human volunteers. Vaccination engendered immunoglobulin G (IgG) antibody, which neutralized the cytotoxic effect of toxin A and promoted the uptake and killing of P. aeruginosa in the presence of human polymorphonuclear leukocytes. Passively transferred IgG isolated from the serum of immunized donors was far more effective at preventing fatal P. aeruginosa burn wound sepsis than paired preimmunization serum. These studies establish the potential usefulness of such a PS-toxin A conjugate as a vaccine against P. aeruginosa.

Human rabies immunoglobulin assayed by the rapid fluorescent focus inhibition test suppresses active rabies immunization

The rabies antibody content of each of ten lots of human rabies immunoglobulin was titrated by both the mouse neutralization test and the rapid fluorescent focus inhibition test. The two tests did not give comparable results, the antibody titres obtained by the mouse neutralization test being 1.4-9.6 times higher than those obtained by the rapid fluorescent focus inhibition test. This titre difference was associated with a consistently lower antibody response in human volunteers who had received post-exposure rabies vaccine treatment which included the administration of RIG assayed by the RFFIT.

Hyperbaric indices (HBI) assess the extent and timing of deviant blood pressure in patients under treatment

Fourteen patients provided data from ambulatory monitoring at 7.5-min intervals for 24h. Rhythm characteristics and measures of blood pressure excess (hyperbaric indices along the 24-h scale) are presented in mmHg/h. A 10-year projection of blood pressure excess exceeded the 1,000,000 mmHg/h limit for systolic blood pressure in 4 cases and for diastolic blood pressure in 1 case. In such cases, additional treatment is urgently indicated, whether or not the mean blood pressure is near or even below the limits indicated by current guidelines.

Absence of myelin basic protein in an improved purified duck embryo rabies vaccine

The encephalitogenic potential of rabies vaccines prepared from nervous tissue is a result of the presence of myelin basic protein. Vaccines prepared from duck embryos are economical and efficient, but, occasionally, cases of allergic encephalomyelitis have been reported. An improved rabies vaccine has been developed that contains the classical Pitman Moore strain of rabies virus grown in embryonated duck eggs. This vaccine has been highly purified and enriched in immunologically effective rabies virus glycoprotein antigen. We have searched for the presence of myelin basic protein using sensitive radioimmunological and immunoblotting techniques. Whereas the classical duck embryo rabies vaccine contained small amounts of myelin basic protein, in the improved purified duck embryo rabies vaccine, none could be detected.

[A highly efficient, highly purified duck embryo rabies vaccine]

At the Swiss Serum and Vaccine Institute, Berne, a highly purified rabies vaccine presenting a high content of effective rabies virus glucoprotein antigen has been developed. The new vaccine is derived from embryonated duck eggs (PDEV). Immunizations performed according to the post-exposure schedule recommended for potent rabies vaccines by the WHO (6 injections on days 0, 3, 7, 14, 28 and 90) already induce protective antibody titers on day 14 (greater than 1 IU/ml). Use of the latest radioimmunological methods did not reveal the presence of myelin basic protein in the new rabies vaccine. Due to improvements of its preparation the rabies vaccine PDEV is an economical and highly efficient vaccine involving only a very remote risk of post-vaccinal encephalitis.

[Field trial with a new human diploid cell vaccine (HDCV) against measles, mumps and rubella]

The results of a field trial with a novel, live attenuated human diploid cell vaccine (HDCV) against measles, mumps and rubella are described. The study was performed double blind and included 120 children aged 15 to 24 months. 60 children received the new vaccine and a control group of another 60 children were vaccinated with M-M-RR II. The seroconversion rates found 6 to 8 weeks after the vaccination were high without exception (95% to 100%). The multiple chi 2-test revealed no statistically significant difference in immunogenic efficacy between the two vaccines (p greater than 0.05). No reports of side effects were received from the 12 physicians participating in the study. It is pointed out that all components of the new vaccine are highly attenuated and that the vaccine is free of avian protein, animal protein extracts and antibiotics. This excludes all theoretical and practical contraindications due to the corresponding hypersensitivities.

[Pre-exposure rabies vaccination using a new duck embryo vaccine]

An economical, highly purified and concentrated duck embryo rabies vaccine (PDEV) was investigated in relation to pre-exposure rabies prophylaxis. The vaccine was injected subcutaneously according to the then prescribed scheme for human diploid cell rabies vaccines (HDCV). Additionally, a third dose was given on day 120. Serum anti-rabies antibody levels were determined on days 0, 56, 120, und 170. On day 56 all volunteers showed an anti-rabies antibody level of at least 1.0 IU/ml, indicating that PDEV is sufficiently immunogenic to allow its use according to the pre-exposure schedules for HDCV. Some rather low titers noted on day 120 indicate that an early booster dose or a third primary immunization dose is justified, as recently recommended by the WHO.

[Immunogenicity of a new, highly purified, highly concentrated duck-embryo rabies vaccine]

The protective value and safety of human diploid cell strain rabies vaccine (HDCV) are well established [6, 8, 11]. At present, however, the high cost and small yields of HDCV has restricted its use, particularly in developing countries where rabies vaccine is needed in large amounts. The inexpensive duck embryo rabies vaccine (DEV), also prepared with the Pitman -Moore strain, is potent and generally safe despite occasional allergic complications [9, 13]. The vaccine has been used with success in several million doses during recent decades [12, 14]. Administered according to the prescribed schedule (14 initial inoculations and 3 boosters), the vaccine has been shown to provide protective antibody titers in pre- and post-exposure use [7, 10]. On the other hand, the immunogenicity of this vaccine did not shorten the administration schedule in a similar way to HDCV. Thus, prior clinical studies using the reduced WHO immunization scheme demonstrated that a concentrated and partially purified DEV containing less than 2.5 IU/ml of rabies antigen elicited sufficient neutralizing antibodies in only 75% of vaccinees [3]. Gl uck et al. [4] clarified the reason for this low immunogenicity: We demonstrated that only about 30-50% of the glycoprotein (GP) in DEV was present on the surface of virus particles. GP, a component of the rabies virus envelope, is the antigen responsible for the induction of neutralizing antibodies. During virus production a non-immunogenic soluble GP may also accumulate. Non-immunogenic GP may be coextracted during vaccine preparation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Physiopathology of anaphylactic and anaphylactoid shock. A cooperative retrospective study]

The pathophysiology of anaphylactic and anaphylactoid shock states suggests that the rapidly initiated, intensive therapeutic measures to be taken must involve: breathing (ventilation) of (with) 100% oxygen, continuous or semi-continuous sympathicomimetic therapy (epinephrine, isoprenalin, orciprenalin) avoiding excessive single doses, rapid intensive volume substitution, control of metabolic acidosis, bronchospasmolytic therapy, in case of laryngospasm intubation, if not possible coniotomy or transtracheal punction. In case of circulatory arrest possibly also cardiac massage, defibrillation, lidocain, cardioversion. In a retrospective study 91 cases of anaphylactic and anaphylactoid shock were analyzed. Cutaneous vascular changes. Vasodilation was reported in 30 cases, vasoconstriction in 15 cases. Hypovolemia. CVP as measured in 23 cases was less than or equal to 2 cmH2O in 12 cases; in 4 of these cases the early finding and in 2 a rather low hematocrit are in favour of venous blood sequestration. In 2 cases the increase of the hematocrit suggests an extravasation of as much as 1,2 and 1,81 of plasma, respectively. Increase of pulmonary arterial pressure. CVP increased in 2 out of 9 cases suggesting a high pulmonary arterial pressure. Decreased cardiac output (CO). In 3 cases CO as determined in a late shock phase diminished by 37--55%. Blood gas changes. PaO2 was as low as 47--61 mmHg in 4 out of 8 cases, PaCO2 being 29--34 mmHg in 2 of them. It suggests an insufficient oxygen transport. Myocardial involvement. Arrhythmias (non sinus-) were found in 38 cases, of which 14 ventricular arrhythmia and 13 asystole. Serious wave deformation concerned QRS (3), AV-block (2), intraventricular blocks (4). 5 times the reaction resulted in myocardial infarction. A localized coronary spasm in anayphylactic shock was observed during a coronary angiography. Respiratory impairment. Severe respiratory impairment was associated with anaphylactic and anaphylactoid shock in 31 cases (26 bronchospasm, 4 apnea, 1 laryngospasm).

[Influenza vaccination with a trivalent whole virus vaccine]

During winter 1979/80 21 trainee nurses aged 18-22 years were vaccinated once with an intact influenza vaccine containing for the first time, two different virus-A subtypes as well as a B-strain. 22 trainee nurses from the same school served as controls. A greater than or equal to 4-fold seroconversion (2 dilution steps) was observed in 67% (A/Texas/77), 83% (A/USSR/77) and 57% (B/Hongkong/73) of the vaccinated, but only in 5% (A/Texas/77, one case) of the non-vaccinated. In the vaccinated group 36 reciprocal titers rose from < 80 to greater than or equal to 80 so that, with 3 exceptions (A/USSR/77, all vaccinees had a reciprocal titer of greater than or equal to 80 after 28 days. In the unvaccinated group only 3 reciprocal titers rose from < 80 to greater than or equal to 80 (A/Texas/77), so that 42 reciprocal titers were still below 80 after 28 days.

[Local reactions after repeated tetanus vaccinations]

Subjects who had exhibited a strong local reaction after vaccination with tetanus toxoid showed a high serum antitoxin titer. This observation confirms earlier findings published in the United States. Since the falloff rate in tetanus antitoxin, year by year, is no more than 30%, such patients should not receive a new booster injection in the following 10 years unless the risk of tetanus is considered great. When boostering these persons, the dose of tetanus toxoid can be reduced to 1-2 Lf.

[Diphtheria epidemic in eastern Switzerland in 1974]

A diphtheria epidemic in the eastern part of Switzerland in 1974 and the measures which were taken for its management and eradication are described. In particular it is pointed out that at present diphtheria displays atypical clinical symptoms in Europe, a fact that renders the diagnosis very difficult in many cases. Therefore, it is important to perform a throat swab in every patient with suspected diphtheria; it is also necessary to explicitly require a search for C. diphtheriae. The early recognition and early treatment of diphtheria with penicillin or erythromycin is of the utmost importance in order to avoid neurological and cardiac complications. With regard to the management and eradication of a diphtheria epidemic, the most important measures are rapid antibiotic protection of all contacts and a widespread immunization of the population. Vaccination of adults with a DiTe vaccine containing a reduced amount of Di-toxoid is recommanded.

Antigangrenous effect of an odontological preparation

Experiments were performed in order to compare the antigangrenous effect of Pyralvex Berna and its components (alcoholic salicylic acid solution and extractum rhei, resp.) with that of an antiphlogistic standard preparation (phenylbutazone). In this experimental model the tails of albino mice are put into water of 55 degrees C for 10 sec. This results in the loss of part of the tail within the following days. In the present investigation, the tail of part of the animals was put into one of the solutions to be examined for 5 sec immediately after exposure to heat as well as on the following 5 days. In the controls 55.65% (on an average) of the original length of the tail were lost, in the animals treated with phenylbutazone 19.10% (on an average) and in the animals treated with Pyralvex 27.25% (on an average) were lost. Thus, the antigangrenous effect of Pyralvex was 77% of that of phenylbutazone. The statistical analysis of the results obtained in the 4th and 5th groups demonstrates that this effect is mainly due to extractum rhei, the antigangrenous effect of which is statistically not significantly different from the antigangrenous effect of Pyralvex (p greater than 0.4).

Minor and trace sterols in marine invertebrates. 1. General methods of analysis

3beta-Hydroxy sterols occurring at a concentration of at least 0.001% of the sterol mixtures of Pseudoplexaura porosa and Plexaura homomalla have been fractionated using a series of refined techniques and subsequently analyzed using combined gas chromatography-mass spectrometry (GC-MS) in the development of a procedure for examining the minor and trace components of marine sterol mixtures. A total of 49 sterols were found which spanned a molecular weight range of 274 to 440. In addition delta4-3-keto analogs of cholesterol, 24-methylcholesterol and gorgosterol were found in the extracts of P. homomalla. Initial separation of various natural sterol-containing conjugates and free sterols was found to have a number of advantages. Fractional digitonin precipitation and alumina column chromatography were found to possess greater sterol separation abilities than previously recognized. Many of the minor sterols were found to possess novel structures including a series of short side chain sterols, 19-nor sterols, 5beta-stanols and 4-monomethyl sterols for which structure elucidation work is continuing.

[Intravenous administration of anti-D hyperimmunoglobulin after mismatched transfusion (author's transl)]

620 ml of 0 Rh-positive blood (310 ml CCD.ee + 310 ml CcD.EE) were administered to a 27-year-old 0 Rh-negative (ccddee) woman in connection with an emergency curettage. 16 hours after this mismatched transfusion an intravenous infusion of anti-D hyperimmunoglobulin was started: 8000 mug (13 mug/ml blood) were given within 14 hours (570 mug/h) under strict supervision. The 10% immunoglobulin preparation had been diluted 20 times. There were only slight variations in heart rate and blood pressure, slight fever and mild increase in serum bilirubin after the infusion. There was slight haemoglobinuria in one urine sample, but no signs of kidney damage. The direct Coombs test was slightly positive after two days, negative after four and six days. The indirect Coombs test was negative after six months. The patient has not become pregnant since. Slow intravenous infusion of highly diluted anti-D hyperimmunoglobulin, under strict clinical supervision, is probably appropriate for Rh prophylaxis after transfusion mismatch. The dose of 13 mug/ml could probably be considerably reduced. 250 mug anti-D per hour should not be exceeded.

[Electrocardiogramme in anaphylactic shock in humans (author's transl)]

Twenty clinical cases described in the literature were gathered, in which electrocardiographic tracings had been recorded. Electrocardiographic changes were found in all cases, such as sinus tachycardia (12 times), impaired electrical conduction (5 times), ventricular overexcitability (7 times), high P-wave (6 times), changes of the ST (10 times), and of the T-wave (18 times). The reason for these changes might be of a complex nature. Based on experimental investiagations mentioned in the discussion, it may be assumed that beside a direct effect on the myocardial cells, the following mechanisms could have influenced the electrical heart potentials: 1. a constriction of the coronary vessels, 2. a pulmonary vascular constriction, 3. an aggregation of thrombocytes, 4. a peripheral vascular dilatation, 5. a bronchiolar constriction.

[Booster vaccination with a diphtheria-tetanus vaccine for dermo-jet with low diphtheria toxoid content]

Indications are provided on how the organization of polyvaccinations against tuberculosis, poliomyelitis and diphtheria-tetanus in school collectivities can be rationalized. 19 persons aged 19-20 years were vaccinated intradermally with 1.5 Lf diphtheria toxoid and 15 Lf tetanus toxoid (contained in 0.1 ml) by means of a single injection with a jet injector (Dermo-Jet). In cases which had not previously been immunized, vaccination with the toxoid doses employed did not induce detectable antitoxin titers. In all cases which had previously been immunized the antitoxin titers after the booster injection were at least 400 times higher than the protection threshold for diphtheria and 1700 times higher than the protection threshold for tetanus. This was also the case in preimmunized cases which had no detectable antitoxin titer before the vaccination. The increase in antitoxin titer was inversely proportional to the prevaccinal titer in the manner of a logarithmic exponential function. It may be concluded from these results that the benefit of a booster vaccination is particularly high in poorly immunized persons whereas it is clearly limited in cases showing a high prevaccinal titer. The well tolerated intradermal vaccination with the jet injector (Dermo-Jet) can be considered as equivalent to the subcutaneous technic. From the point of view of organization (time consumption, problems of sterilization) this method is much preferable to intramuscular or subcutaneous vaccination.