Bactericidal activity of lansoprazole and three macrolides against Helicobacter pylori strains tested by the time-kill kinetic method.

The bactericidal activities of macrolides (clarithromycin, roxithromycin and azithromicyn) and lansoprazole, alone and in combination, against Helicobacter pylori strains were evaluated. It was found that the association of lansoprazole and clarithromycin resulted in a marked synergism, while the combination of roxithromycin or azithromycin with lansoprazole had synergistic and additive effects.

Induction of interleukin 1 alpha in murine macrophages infected in vitro with different species and strains of Leishmania.

It is now generally agreed that several cytokines released by immunocompetent cells such as macrophages play a crucial role in the outcome of infections caused by protozoa belonging to the genus Leishmania. In particular, tumor necrosis factor (TNF) induction during the course of cutaneous leishmaniasis has been related to resistance to L. major infection in mice. However, the role played by interleukin 1 (IL-1) in the host response to leishmaniasis has yet to be completely elucidated. The aim of this work was to study whether different species and strains of Leishmania could induce IL-1 alpha in murine macrophages in vitro. Resident peritoneal macrophages of BALB/c and C3H/HeN mice were infected with L. donovani, L. major, or different strains of L. infantum. It was found that L. donovani did not induce IL-1 alpha in macrophages from either mice strain. Infection with L. major or with three out of six strains of L. infantum induced consistent amounts of IL-1 alpha, but only in macrophages from genetically resistant C3H/HeN mice. No relationship was found between the rate of infection of macrophages and the amount of IL-1 alpha detected in the supernatants of infected macrophages. Data obtained confirm that the release of IL-1 alpha by murine macrophages infected in vitro with Leishmania is influenced by the genetic background of the cells as well as by the parasite species.

Specificity and protective activity of murine monoclonal antibodies directed against the capsular polysaccharide of type III group B streptococci.

We have obtained 41 monoclonal antibodies directed against type III group B streptococci by immunizing Balb/c mice with formalin-killed bacteria. All of these antibodies reacted with purified type-specific carbohydrate by enzyme-linked immunosorbent assay and immunoprecipitation tests. The epitope recognized by all of these antibodies was associated with terminal sialic acid residues, as indicated by abrogation of immune reactions by treatment of the type-specific carbohydrate with neuraminidase. Two purified monoclonal antibodies (the IgM P9D8 and the IgG3 P4F12) were further characterized for their protective activity in a neonatal rat model of infection. P9D8 and P4F12 antibodies were significantly protective when administered in a dose of 0.5 and 2.5 mg/kg, respectively, at the same time as 3 x 10(5) colony forming units of type III streptococci. Protection was still observed when the antibodies were given up to 9 h after challenge. No protection was afforded against infections with type Ia/c and II streptococci. Similarly, both antibodies effectively opsonized type III, but not Ia, Ib or II bacteria, in an in vitro assay. These and similar, previously described, monoclonal antibodies may be useful, possibly after "humanization" by genetic engineering, for the therapy of neonatal group B streptococcal infections.

Purification and isolation of choline acetyltransferase from the electric organ of Torpedo marmorata by affinity chromatography.

Choline acetyltransferase (EC 2.3.1.6) catalyzes the synthesis of the neurotransmitter acetylcholine from acetylcoenzyme A and choline. It has been purified from the electric organ of Torpedo marmorata by a new double-affinity chromatography. Our rapid and specific purification procedure includes affinity chromatography on CoA-Sepharose and then a second affinity chromatography on the enzyme's inhibitor [2-[3-(2-ammonioethoxy)-benzoyl]ethyl]trimethylammonium bromide coupled to Sepharose via a six-carbon spacer arm. The final enzyme preparation has been purified 7300-fold to a specific activity of 73 mumol acetylcholine formed min-1 mg protein-1. The isolated enzyme gave a single band on disc polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The relative molecular mass was determined to be 68,300 +/- 2100.

[Tobacco dependence: first risk factor of atherosclerosis. Survey among smokers and non-smokers in group dynamics]. / Dépendance tabagique: premier facteur de risque de l'athérosclérose. Enquête auprès de fumeurs et de non fumeurs dans une dynamique de groupe.

Several epidemiological and experimental studies have demonstrated an increased risk of atherosclerosis in smokers. The secondary prevention of this risk factor is only possible, presently, through anti-tobacco consultations. Several approaches are possible but there are many recurrences within the year following the wean-off. In a group dynamics, including patients having tried another method, we have conducted an investigation among inveterate smokers (n = 106), former smokers (n = 50) and a group of non-smokers (n = 34). Group dynamics remains a suitable method for smokers willing to get rid of their addiction. The number of daily cigarettes consumed by inveterate smokers is considerably and lastingly reduced, and 27 p. cent of the patients quit smoking. Monitoring of laboratory tests (HbCo, Blood count, HDL-cholesterol, thiocyanate, etc.), electrocardiogram and chest X-Ray, completes this weekly consultation and permits a stronger motivation for the smoker to quit smoking. Sometimes associated with acupuncture or homeopathy, this method permits a progressive de-conditioning from tobacco addiction.

Long-term analgesic reaction in attacked mice.

Four experiments were designed to characterize long-term analgesic (LTA) reaction in attacked mice. In Experiment 1 we showed that analgesic reaction in DBA mice, induced by the stress of being attacked (30 or 50 bites), is reinstated upon reexposure to seven bites 24 hr later. The magnitude of the LTA response depended on the level of analgesia on Day 1 and was smaller than the original response. In Experiment 2 we showed that LTA was prevented by naloxone or beta-chlornaltrexamine given before exposure (50 bites) on Day 1. Results of Experiment 3 revealed that naloxone or beta-chlornaltrexamine injected before reexposure to seven bites on Day 2 antagonized LTA measured 10 min, but not 1 min, after reexposure. In Experiment 4 we showed that morphine substituted for being attacked on Day 1 failed to produce LTA. We concluded that pain inhibitory mechanisms remain in a state of increased readiness for at least 24 hr after attack stress and that activation of opioid systems is necessary but not sufficient to produce LTA, a response that is only partly sensitive to opioid antagonists.

Preexposure to a nonaggressive opponent prevents low-intensity, social-conflict analgesia in mice.

In a first experiment, exposure of DBA/2 mice to a small number of attack bites by a C57BL/6 mouse resulted in low-intensity analgesia as assessed by the tail-flick test. The analgesia dissipated within 10 min and was insensitive to naloxone (10 mg/kg, sc) but was antagonized by the irreversible opioid antagonist beta-chlornaltrexamine (5 mg/kg, sc). In a second experiment, preexposure to a nonaggressive C57BL/6 opponent prevented low-intensity analgesia induced by a small number of attack bites 24 hr later. The preexposure effect was abolished by naloxone (10 mg/kg, sc) given before the nonaggressive confrontation. This suggests that the release of endogenous opioids during preexposure interferes with the subsequent activation of endogenous opioid-mediated pain control mechanisms.

Sarin poisoning in guinea pigs compared to reactivation of acetylcholinesterase in vitro as a basis for therapy.

Contrary to the large number of publications dealing with treatment of organophosphate poisoning in a variety of animal species, there is no logic reason in the preference of one species, for this purpose. Guinea pigs were reported to respond better to treatment by oximes, than mice and rats. However, in the analysis of data on the effect of obidoxim and atropine or benactyzine on sarin poisoning it is demonstrated, that guinea pigs do not respond differently from mice and rats. Subcutaneous LD50's of sarin in mice ranged from 0.06 to 0.207 mg/kg, and those of guinea pigs from 0.04 to 0.112 mg/kg. The difference in the LD50's may be related to the different susceptibility of various animal species. The importance of "in vivo" dosage, mode of application, kinetics of antagonists, in correlation to the ability to reactivate "in vitro" is discussed.

Blockade of acetylcholine synthesis in organophosphate poisoning.

In spite of worldwide research efforts in the search for the treatment of organophosphate poisoning, the substances with practical antidotal capabilities remain to be discovered. This problem has generally been approached by attempting to reactivate the inhibited acetylcholinesterase. Our approach consisted of reducing the amount of the lethal agent acetylcholine by blocking its synthesizing enzyme cholineacetylase with methyl methane thiol sulfonate (MMTS). We have taken into consideration that we are dealing with acute toxicological problems. This applies for poisoning as well as for treatment, and therefore in the present stage we can only present minimal results. The time from sarin (2 mg/kg) injection to death in rats (controls) was 2:59 min. With a MMTS dosage of 133.5 mg/kg prior to sarin, it was prolonged to 20:55 min (p less than 0.01). With the same dosage of MMTS under identical conditions, the time from soman (2 mg/kg) injection to death was prolonged from 6:08 to 14:48 min (p less than 0.01). Although MMTS cannot be used as a therapeutic agent, our attempt has demonstrated a utility in treating organophosphate poisoning in mice and rats and points in a direction where further work might be fruitful.

Inhibition of morphine-induced analgesia and locomotor activity in strains of mice: a comparison of long-acting opiate antagonists.

The long-acting opiate antagonistic potency of naloxazone (NXZ), beta-chlornaltrexamine (beta-CNA) and beta-funaltrexamine (beta-FNA) was compared using three inbred strains of mice, in which morphine induces either analgesia (DBA/2), locomotion (C57BL/6), or both responses (C3H/He). The antagonists were applied SC 24-120 hr before morphine (10 or 20 mg/kg, IP), followed by the tests after 30 min. The minimal dose which completely antagonized morphine-induced analgesia in DBA and locomotion in C57 mice during 24 hr were: for NXZ 50 and 100 mg/kg, for beta-CNA 0.8 and 6.2 mg/kg, for beta-FNA 1.6 and 12.5 mg/kg, respectively. beta-FNA and beta-CNA more potently blocked morphine-induced analgesia in DBA mice than the activity response in the C57 strain. In contrast, beta-FNA prevented morphine-induced locomotion at a lower dose (6.2 mg/kg) than analgesia (greater than 50 mg/kg) in C3H mice, while beta-CNA was equipotent (1.6 mg/kg). In general, beta-CNA turned out to be the most reactive compound, antagonizing morphine effects in low doses up to 120 hr. beta-FNA selectively antagonized either morphine-induced analgesia or locomotion, depending on the strain used. This suggests that a given morphine response might be caused by a genetically determined multiplicity of opiate receptor types and their mutual interactions.