Crystallization and preliminary X-ray diffraction studies of beta-cryptogein, a toxic elicitin secreted by the phytopathogenic fungus Phytophthora cryptogea.

Crystals of the basic elicitin secreted by Phytophthora cryptogea have been obtained by the hanging-drop method of vapor diffusion from sodium chloride solutions. The crystals belong to the tetragonal space group P4(1)22 (or enantiomorph P4(3)22), with unit cell dimensions a = b = 47 A, c = 137 A and probably contain two molecules per asymmetric unit. The crystals are very stable to X-rays and diffract to 2.2 A resolution on a synchrotron radiation source.

Human eosinophils in culture undergo a striking and rapid shrinkage during apoptosis. Role of K+ channels.

In the absence of appropriate stimulus, eosinophils in vitro rapidly exhibit the features of apoptotic cells (nuclear pycnosis, cell shrinkage, DNA fragmentation). By using electronic cell sizing, we precisely measured the volume distribution of human eosinophils during apoptosis. We observed that apoptosis of eosinophils was accompanied by a marked cell volume decrease (approximately 60%). Moreover, analysis of the volume distribution in different experimental conditions (kinetics of apoptosis, inhibition of apoptosis by cytokines) revealed that the cell shrinkage, once triggered, was a fast process in which the intermediate states between normal and shrunken volume had a short half-life. As a model of apoptosis, the eosinophil model allowed us to test the hypothesis that apoptotic cell shrinkage was linked to osmotic changes due to leakage of internal ions. Indeed, in the presence of K+ channel blockers, the shrinkage was inhibited in a dose-dependent manner. In conclusion, our results suggest that eosinophil shrinkage during apoptosis is a striking and rapid phenomenon and osmotic changes due to K+ efflux could be responsible, at least in part, of the volume decrease.

[Anaemia, cardiac failure and erythropoietin]. / Anémie, insuffisance cardiaque et érythropoïétine.

Anaemia is common in severe cardiac failure due to systolic dysfunction. The mechanisms are varied. Anaemia is a negative prognostic factor. Treatment with erythropoietin seems to improve the quality of life, functional status, effort tolerance and systolic function of these patients. Large scale clinical trials are on-going.

[Therapeutic education for cardiac failure patients: the I-care programme]. / Education thérapeutique des patients insuffisants cardiaques: le programme I-care.

Therapeutic education is becoming increasingly important in the management of chronic diseases including cardiac failure. The I-CARE programme consists of an evaluation of the role of therapeutic education in France, creating standardised tools and setting up training sessions for therapeutic education in the context of cardiac failure. Approximately two thirds of the French centres contacted perform therapeutic education with their available means. The lack of personnel, space, and training tools represent obstacles to the development of therapeutic education. The tools developed in the programme fall into 5 areas: diagnosis education, understanding the illness, diet, physical activity/daily life, and treatment. Training sessions were organised for the teams, consisting of at least one cardiologist and nurse. The I-CARE programme should allow the expansion of therapeutic education for cardiac failure and improve the multidisciplinary management of this disease which increasingly affects often elderly subjects.

Effects of nitric oxide on the eosinophil survival in vitro. A role for nitrosyl-heme.

In a previous paper we showed that the nitric oxide (NO) donors azide and hydroxylamine inhibited eosinophil apoptosis. Azide and hydroxylamine generate a nitrosyl-heme complex - due to endogenous catalase activity - which activates soluble guanylate cyclase. In contrast, in the present paper, we show that NO donors (SNAP, SIN-1, S-nitroso-L-cysteine, NOC-18) which spontaneously release NO in physiological solutions did not support the survival of eosinophils and induced apoptosis or necrosis. However, the addition of hematin (the ferric form of heme) together with low doses of NO (SNAP 10 microM) promoted eosinophil survival. In conclusion, we propose that NO and heme (e.g. from heme-containing enzymes such as peroxidase or catalase), both released in inflammation sites, could form nitrosyl-heme and thus promote eosinophilic inflammation.

The nitric oxide donors, azide and hydroxylamine, inhibit the programmed cell death of cytokine-deprived human eosinophils.

Azide and hydroxylamine release nitric oxide (NO) enzymatically in biological conditions. We observed that both compounds were able to inhibit in vitro the programmed cell death of human eosinophils from peripheral blood. This protective effect could be mimicked by permeable cGMP analogs and by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine. Moreover, the soluble guanylate cyclase inhibitor LY-83583 inhibited in a dose-response manner the effects of the NO donors. Consequently, via the increase of eosinophil survival, NO could contribute to the amplification of inflammatory and allergic processes. This effect appears to be mediated, at least in part, by the soluble guanylate pathway.

Voltage-dependent ion channels on human basophils: do they exist?

The presence of voltage-dependent ion channels (particularly Ca2+ channels) on the surface of 'non excitable' cells such as human basophils is a matter of debate. Indeed, in basophils, Ca2+ entry or mobilization is not sufficient by itself to trigger secretion, although enhanced cytosolic Ca2+ concentration increases it. In order to address this question, we used a two-signal model and we report here experiments which suggest the presence of voltage-dependent structures directly or indirectly linked to membrane Ca2+ pathways. Indeed, it is known that, in the presence of PMA at threshold concentration (1st signal), elevation of cytosolic Ca2+ (2nd signal) induces histamine release. We observed that a depolarizing external solution (high K+) induced a Ca(2+)-dependent release of histamine from PMA-treated human basophils. High K+ alone did not induce histamine release. Although the voltage-sensitive component and the physiological relevance of this mechanism remain to be defined, these results suggest that this voltage-dependent Ca2+ influx in the human basophil could contribute to the up-regulation of histamine release.

Effect of sodium cromoglycate and nedocromil sodium on anti-IgE-induced and anti-IgG4-induced basophil degranulation.

Both anti-IgE and anti-IgG4 induce human basophil degranulation as assessed by toluidine blue staining. Anti-IgG4 has been recently shown to act on the human basophil by a 2-step process: anti-IgG4 induces the release from eosinophils of eosinophil cationic proteins which in turn induce human basophil degranulation. In the present study, we show that sodium cromoglycate and nedocromil sodium have no direct effect on human basophil degranulation but inhibit the anti-IgG4-induced degranulation. This effect was dose-dependent and significant inhibitions were obtained at 2.5 to 25 mumol/L for sodium cromoglycate and 25 mumol/L for nedocromil sodium. No drug effect was observed on the basophil degranulation induced by supernatants from anti-IgG4-stimulated eosinophils. However, the release of basophil degranulating factors (eosinophil cationic proteins) by anti-IgG4 from purified eosinophils was significantly inhibited after preincubation with 25 mumol/L of sodium cromoglycate or nedocromil sodium. Taken together, these results indicate that both sodium cromoglycate and nedocromil sodium have an inhibitory effect on the first step of anti-IgG4-induced human basophil degranulation, thus strongly suggesting that these drugs inhibit the release of eosinophil cationic proteins from human eosinophils.

Adolescent drug use: findings of national and local surveys.

Adolescent drug use increased until about 1981, but since then it has steadily declined. Current data show some drug use in the 4th and 5th grades and considerable increases from the 6th to the 9th grades. For drugs such as marijuana, cocaine, and stimulants, lifetime prevalence continues to increase through high school; for drugs such as inhalants and heroin, lifetime prevalence may decline for Grades 10, 11, and 12, suggesting that students who use these drugs early may drop out. Drug use of rural youth is similar to that of other youth. Barrio, ghetto, and Native-American reservation youth may have high rates of use, but use of Black and Hispanic seniors may be equivalent to or less than that of White seniors. National data and broadly defined ethnic data, however, may cover up important subgroup differences. For example, Western Mexican-American girls have lower use than Western Spanish-American girls, possibly because of the greater influence of "marianisma." Different locations may also have very different patterns of adolescent drug use, calling for different types of local intervention.

Links from emotional distress to adolescent drug use: a path model.

Administered anonymous surveys asking about drug use, emotional distress, and peer drug associations to 11th and 12th grade high school students (N = 563). Emotional distress variables accounted for only 4.8% of the variance in drug use. The addition of peer drug associations as a predictor variable increased the variance accounted for to 43.4%. A path model of adolescent drug use based on peer cluster theory was tested using LISREL, and this provided a good fit with the data. As predicted, peer drug associations dominated the prediction of drug use and mediated the effect of emotional distress on drug use, with the exception of a small residual path directly from anger to drug use. The hypothesis that young people take drugs to alleviate emotional distress does not hold up well; emotional distress variables, with the exception of anger, produced only very small and indirect links to drug use.

American Indians and alcohol.

The high prevalence of alcohol use and its consequences among American Indians may be attributed to a number of factors, including the influence of the European colonists who first made large amounts of alcohol available to Indians, as well as current social and cultural factors. Efforts to prevent and treat alcohol problems among the American Indian population may be more effective if native beliefs and approaches are incorporated. Alcohol problems also may be prevented through policies regulating the sale and use of alcohol in Indian communities.

Regulation of human basophil activation. IV. Dissociation between cationic dye binding and histamine release: role of Ca2+ ions.

In previous studies we observed that in vitro histamine release from human basophils could be dissociated from the loss of affinity of basophil granules for a cationic dye, toluidine blue. In the present study we further explored the intracellular signals leading to the decrease in toluidine blue positive basophil (TB+) numbers, with or without histamine release. Since Ca2+ mobilization is a crucial event in secretion and particularly in histamine release, we studied the role of Ca2+ in histamine release as compared to TB+ decrease. In the presence of external Ca2+ (2 mM): i) Ca2+ channel antagonists verapamil and nifedipine up to 10 microM were without effect on IgE-mediated histamine release and TB+ decrease; ii) loading of the leucocytes with Quin2 or preincubation with TMP-8, an internal Ca2+ antagonist, significantly inhibited the release of histamine and the decrease of TB+ basophils. In the absence of added external Ca2+:i) histamine release was abolished whereas the decrease of TB+ was not modified, even in the presence of EGTA;ii) the decrease of TB+ could be inhibited by prolonged EGTA preincubation, by Quin2 loading and incubation with TMB-8. We conclude that histamine release requires both external Ca2+ influx and mobilization of internal Ca2+. In contrast, no influx of external Ca2+ is required for TB+ decrease in which, however, internal Ca2+ mobilization appears to play an important role.

Anti-IgE induces the opening of non selective cation channels on human basophils.

Basophils play a major role in allergic reactions-particularly in late phase reactions-by releasing histamine and other mediators of inflammation. Although transmembrane ion fluxes are thought to play an important role in the modulation of histamine release, little is known about ion pathways through the basophil membrane. We thus studied human basophils from normal subjects (n = 25 cells) with the patch-clamp method. We observed that IgE-dependent activation of human basophils led to the opening of non selective cation channels with a 20pS conductance. This was obtained when the patch pipette was applied onto the cell surface and sealed onto it in order to measure transmembrane currents on a small surface of intact basophils (cell-attached configuration). Non selective channels with the same 20pS conductance were also observed when a membrane patch was detached from basophil and its inner side placed in a Ca(2+)-containing medium (inside-out configuration). These data are a first contribution of the patch-clamp method in the understanding of ion movements in human basophils.

In vitro effects of Uriage spring water on the apoptosis of human eosinophils.

The influx of eosinophils in tissues plays a central role in the pathophysiology of allergic diseases such as allergic rhinitis, allergic asthma or atopic dermatitis. The death of eosinophils by apoptosis is an important factor for the resolution of hypereosinophilia. In the present study, we have shown that Uriage spring water induced in vitro the apoptosis of IL-5-primed eosinophils. This effect was dose-dependent and was statistically significant at Uriage water concentrations above 20%. The induction of apoptosis was related to the Ca2+ content of Uriage water. Indeed, Ca2+ at the same concentration as in Uriage water mimicked the apoptotic effect of the spring water. Furthermore, EGTA reversed the apoptotic effect of Uriage water. These results suggest that topically applied, Uriage water could contribute to the resolution of eosinophilic inflammation.

Male adolescents' reactions to TV beer advertisements: the effects of sports content and programming context.

OBJECTIVE: This study examines white male adolescent responses to TV beer advertisements with and without sports content and to nonbeer ads when embedded in sports and entertainment programming. METHOD: A total of 72 advertisements and 24 television program excerpts were randomly sampled from national television programming. White male adolescents (N = 157) recruited in a public school system each viewed six ads (one of each of three types of ad embedded in each of two types of programming) comprising the 2 x 2 x 3 factorial, within-subjects, mixed-model (random and fixed effects) experimental design along with an age-level blocking factor and random factors for commercial and program stimuli. Cognitive responses to each ad were content-analyzed. Individual difference variables including alcohol use behavior, sensation-seeking, masculinity and sports involvement were also measured. RESULTS: Subjects showed a consistent preference for beer ads with sports content. A significant three-way interaction between ad type, programming type and junior versus senior high-school age level also indicated that sports programming had an inconsistent effect on responses to beer ads but that nonbeer ads were responded to more positively during sports than during entertainment programming. Other analyses showed that subjects were more cognitively resistant to beer ads than to nonbeer ads. CONCLUSIONS: These results support public and official concerns that sports content in beer ads increase the ads appeal to underage youth. They do not support hypothesized concerns that sports programming might prime adolescents to be more receptive to beer ads. Implications for alcohol education efforts are discussed.

An integrated model for prevention and treatment of drug abuse among American Indian youth.

American Indian youth have been shown to be at high risk for drug abuse. Epidemiological studies of Indian school students over the past two decades have revealed rates of use consistently higher than those found for other youth. Socioeconomic and historical factors have led to conditions that put a great deal of stress on the family and other support systems which in part account for the seriousness of the problem. A model is presented which can guide both prevention and treatment efforts addressing drug abuse in Indian communities. Five variable domains, social structure, socialization factors, psychological variables, peer associations and drug use, are related in an integrated structure. By following the progression of the etiological variables, a stepwise plan can be developed to organize interventions. Although the model has immediate utility, a number of further research questions are outlined that will enhance its application.

Patterns of alcohol use among ethnic minority adolescent women.

There is agreement in the literature that women of the major ethnic groups in the United States have lower rates of alcohol use and suffer fewer alcohol-related problems than men. In adolescence, the highest rates of alcohol use are generally found among American Indians, followed in decreasing order by whites, Hispanics, African-Americans, and Asian-Americans. The role of sociocultural factors in alcohol use as found in the literature is discussed, including level of acculturation, generational status, culturally specific values and beliefs and peer influence. Lifetime and last 30-day prevalence, age of first time drunk, and peer sanction data from the 1989-93 database of The American Drug and Alcohol Survey are presented by gender and ethnicity for 8th and 12th graders. These data show similar rates of alcohol use by males and females in the 8th grade but more use by males in the 12th grade for all ethnicities except American Indians who live on reservations.

[The echocardiographic examination in adult cardiomyopathy]. / L'examen échocardiographique des cardiomyopathies de l'adulte.

Echocardiography allows distinction between the diastolic dysfunction of hypertrophic or restrictive cardiomyopathies and the systolic dysfunction of dilated cardiomyopathy. The diagnosis and prognosis may be deduced from echocardiographic parameters. In hypertrophic cardiomyopathy systolic function is normal and there is asymmetric left ventricular hypertrophy (> 13 mm) associated with a reduced diastolic dimension and atrial dilatation resulting from diastolic dysfunction. The prognosis could be related to the severity of left ventricular hypertrophy; right ventricular hypertrophy is uncommon and its severity seems to be related to that of left ventricular hypertrophy. Restrictive cardiomyopathies are less common and amyloidosis is the commonest cause. Symmetric hypertrophy with reduced diastolic dimensions is observed; right ventricular involvement occurs in about 30% of cases. The prognosis seems to be related to the degree of parietal infiltration and, at advanced stages, systolic function is abnormal (fractional shortening < 20% with a left ventricular diastolic dimension > or = 55 mm) and rapidly fatal. Dilated cardiomyopathy is diagnosed when wall thickness is normal but left ventricular diastolic dimensions > 27 mm/m2 and ejection fraction < 45%. Right and left ventricular dimensions of the same size, left ventricular diastolic dimensions > 70 mm and left ventricular ejection fractions < 20% are poor prognostic indicators.

[How to evaluate the hemodynamic risk after myocardial infarction?]. / Comment évaluer le risque hémodynamique au décours d'un infarctus du myocarde.

The hemodynamic prognosis of myocardial infarction is determined, at medium and long term, by the function of the left ventricle. This is related to the infarct size, the dilatation and geometry of the ventricle secondary to left ventricular remodeling which often follows infarction. In addition to clinical criteria, the hemodynamic parameters which are essential for patient evaluation are the ejection fraction (by radionuclide or conventional ventriculography), rapidly progressive ventricular dilatation (by repeated echocardiography) and circulatory reserve from the exercise stress test data.

Occult participation: its impact on adolescent development.

This study investigated the relationship between occult participation, substance abuse, and level of self-esteem in adolescents. Data were collected from 50 adolescents who ranged in age from 12 to 19 years and who spoke English as their primary language. The combined group of adolescents consisted of 25 clinical and 25 nonclinical youth. Participants completed a three-part questionnaire package which included Rosenberg's Self-Esteem Scale, the Adolescent Magic Questionnaire, and the Drug and Alcohol Assessment Scale. Results indicated that adolescent substance abuse and occult participation were significantly related. High and low occult participation groups were determined, and significant differences were found between the high versus low occult groups when compared on the primary variables of self-esteem and substance abuse. Significant differences were also noted when comparing the high versus low occult groups with various psychosocial developmental variables. Included is a discussion of the impact of occult participation on the psychosocial elements of adolescent self-esteem, self-concept, tolerance for deviance, and religious involvement.