Electrical transport and giant magnetoresistance in La0.75Sr0.25Mn1-xCrxO3 (0.15, 0.20 and 0.25) manganite oxide.

We have investigated the influence of chromium (Cr) doping on the magneto-electrical properties of polycrystalline samples La0.75Sr0.25Mn1-xCrxO3 (0.15 ≤ x ≤ 0.25), prepared by the sol-gel method. Comparison of experimental data with the theoretical models shows that in the metal-ferromagnetic region, the electrical behavior of the three samples is quite well described by a theory based on electron-electron, electron-phonon and electron-magnon scattering and Kondo-like spin dependent scattering. For the high temperature paramagnetic insulating regime, the adiabatic small polaron hopping (SPH) model is found to fit well the experimental curves.

["Smoker's paradox" and reperfusion's strategy in acute myocardial infarction]. / "Paradoxe des fumeurs" et stratégie de reperfusion à la phase aiguë de l'infarctus du myocarde.

UNLABELLED: Previous studies have shown that smokers with acute myocardial infarction (AMI) treated by thrombolysis have lower mortality rates than nonsmokers, a phenomenon often termed "smoker's paradox". This "smoker's paradox" has been rarely studied in case of primary angioplasty. AIM OF THE STUDY: To evaluate the impact of smoking status on the early mortality of patients admitted with AMI with regard to the strategy of reperfusion (intravenous thrombolysis versus primary angioplasty). PATIENTS AND METHODS: Study undertaken from the Monsatir registry of ST elevation MI including 688 patients having had either a hospital or a prehospital thrombolysis (n=397) or a primary angioplasty (n=291). Among those patients, 482 (70.1%) were active smokers. RESULTS: In the thrombolysis group, the prevalence of hypertension, diabetes and anterior location of MI was significantly less among smokers. In the group primary angioplasty, only diabetes and hypertension were less frequent. The immediate mortality was significantly less among smokers in case of thrombolysis comparatively to non-smokers (5.3 vs 13%; p=0.008). By multivariate analysis, cardiogenic shock (p<0.0001), anterior MI (p=0.03) and active smoking (p=0.03) were independent predictive factors of mortality in case of thrombolysis. A trend toward a lower mortality among smokers was observed in the primary angioplasty group (10 vs 17.6%; p=0.07). CONCLUSION: "The smoker's paradox" seems to be observed mainly among patients having had thrombolysis.

Platelet-specific alloantigens and antibodies in Tunisian women after three or more pregnancies.

Pregnancy may allow alloimmunization against human platelet antigens (HPA), which can lead to neonatal alloimmune thrombocytopenia (NAIT). The specificities of alloantibodies are closely related to the distribution of the HPA systems. A total of 281 Tunisian multiparous women (mean number of pregnancies: 4.5) were phenotyped for the HPA-1, -3 and -5 systems, by monoclonal antibody immobilization of platelet antigens (MAIPA). We searched for antibodies against HPA-1a, HPA-3a, HPA-5b and HPA-5a in HPA-1b1b, HPA-3b3b, HPA-5a5a and HPA-5b5b individuals, respectively. The gene frequencies were: 0.83 for HPA-1a, 0.17 for HPA-1b, 0.78 for HPA-3a, 0.22 for HPA-3b, 0.82 for HPA-5a and 0.18 for HPA-5b. Anti-HPA-5b antibodies were present in eight sera and anti-HPA-3a antibodies were present in one serum. The anti-HPA-5b system is the most frequently involved in platelet alloimmunization in Tunisian multiparous women. However, prospective trials are required to confirm this result and to determine the exact frequencies and clinical relevance of platelet alloantibodies in pregnant Tunisian women.

[Anomalous left main coronary artery with an inter-aorto-pulmonary trajectory: diagnostic value of 64-slice CT scan with cardiac synchronisation]. / Anomalie de naissance du tronc coronaire gauche avec un trajet interaortopulmonaire: apport du scanner 64 coupes avec synchronisation cardiaque.

Anomalous left coronary artery arising from the right sinus with an inter-aorto-pulmonary trajectory is a classical cause of sudden death and myocardial ischaemia in young adults. The mechanism is compression of the coronary during physiological dilatation of the great arteries on exercise. The authors report the case of a 12 year old child who had syncope on effort preceded by angina due to this malformation. The CT scan with 3-D reconstruction confirmed the diagnosis and the interarterial trajectory of the left coronary artery and the anatomical relationships with the vessels at the base of the heart. Cardiac CT scan is the investigation of choice for diagnosis and preoperative work-up of congenital coronary anomalies. In the authors' experience, the investigation is performed systematically when an anomalous coronary artery is suspected, in addition to echocardiography and instead of conventional coronary angiography.

New data on the occurrence of ochratoxin A in human sera from patients affected or not by renal diseases in Tunisia.

Ochratoxin A is often found in the sera of people exposed to this mycotoxin in their food (cereals such as barley, coffee, wines, fruit juices, spices, products of animal origin such as pig and poultry offal). Ochratoxin A is suspected of playing a role in the Balkan Endemic Nephropathy, a nephropathology described in Balkan areas where ochratoxin A is often found in cereals and in pork-derived products. In North Africa like Tunisia where high incidence of chronic interstitial nephropathies of unknown aetiology are pointed out, the involvement of ochratoxin A was suspected but contradictory studies on the degree of human exposure did not succeed in evidencing the role of ochratoxin A. In the present work, sera from 47 volunteers hospitalised for nephropathic damages including bladder tumours (21 people), and from 62 patients hospitalised for disorders other than nephropathic ones, were analysed for ochratoxin A contents. The determination of ochratoxin A in sera was done by a validated immunoaffinity-HPLC method. Sera from unaffected population exhibited percentages of 74.2%, 22.6% and 3.2% containing ranges of ochratoxin A as <0.10-0.5 microg/l, 0.51-1.0 microg/l and above 1.0 microg/l respectively. For patients affected with renal diseases, percentages were 59.5%, 25.5% and 14.9% on the same ranges of ochratoxin A levels respectively. The average ochratoxin A concentration for patients with urinary tract disease excluding cancer patients was 0.99+/-1.28 microg/l while that for the non-nephropathic patients was 0.53+/-1.00 microg/l. However the average levels in the cancer patients was only 0.26+/-0.20 microg/l. Those results are in line with most of previously published works and did not confirm very high ochratoxin A contents found in other reports from same regions.

In vitro antiviral activity of dermaseptins against herpes simplex virus type 1.

The in vitro antiviral activity of dermaseptins (S1-S5) against herpes simplex virus type 1 (HSV1) was investigated. These peptides were incubated with the virus and its target cells under various conditions, and their effects were examined by the cytopathic effect inhibition assay or by reduction in virus yield in Hep-2 cell cultures as well as by direct immunofluorescence. Dermaseptin S4 displayed the strongest antiviral effect against HSV1, at micromolar doses. Experiments including acyclovir as a reference antiviral agent were performed to investigate the mode of action of this dermaseptin. In contrast to acyclovir, dermaseptin S4 showed its inhibitory effect only when applied to the virus before, or during virus adsorption to the target cells. This suggested that the activity of this dermaseptin was exerted at a very early stage of the viral multiplication cycle, most likely at the virus-cell interface.

[An ischemic pulmonary malformation of the surviving fetus occurring after selective embryo reduction in bichorionic pregnancy. Report of one case and literature review]. / Une anomalie pulmonaire ischémique inhabituelle du foetus survivant après interruption sélective sur grossesse bichoriale. A propos d'un cas et revue de la littérature.

We describe, to our knowledge, the first case of a pulmonary malformation called acinar dysplasia occurring at a surviving fetus after selective embryo reduction in a bichorionic pregnancy. The chronological and histological observations suggest that this anomaly may be linked with a feticide achieved at 13 week's gestation. Literature review concerning selective embryo reduction shows rare cases of vascular connections in bichorionic pregnancies especially during the first half of gestation, that can explain in part the apparition of survivor's anomalies.

[Testicular feminization syndrome associated with acute hydramnios: apropos of 1 case]. / Le syndrome du testicule féminisant associé à un hydramnios aigu. A propos d'un cas.

We describe the first, to our knowledge, case of a feminizing testicle associated with acute polyhydramniosis observed at 21 weeks 3 days gestation. There was no fetal malformation or maternal disease that would explain the polyhydramnios. Prenatal diagnosis of feminizing testicle can now be made but is very difficult to suspect without similar family history or a suggestive ultrasonographic sign. Many fetal malformations have been directly linked to different causes of feminizing testicle, but for other malformations such as acute polyhydramnios, the pathogenesis remains unknown.

[Nuchal translucency: screening for chromosomal abnormalities and congenital malformations. Multicenter study]. / Clarté nucale: dépistage des anomalies chromosomiques et des malformations congénitales. Etude multicentrique.

OBJECTIVE: To value the rate of chromosomal abnormalities and evolution of children who had a prenatal diagnosis of fetal nuchal translucency in the first trimester. MATERIAL AND METHODS: Multicenter prospective study conducted in 4,582 patients who had a first ultrasonography between 10 and 14 weeks' gestation (abdominal and/or transvaginal sonography). The measurement of fetal nuchal translucency was performed by mid-sagittal section and when it was higher than 2.5 mm a fetal karyotype was made. RESULTS: Three hundred and fifty eight nuchal translucencies (> 2.5 mm) were diagnosed and 334 karyotypes were done. We found 25 chromosomal anomalies (7.4%): 14 trisomies 21; 7 trisomies 18; 2 trisomies 13; one triploidy and one trisomy X. The postnatal examination of children detected three congenital malformations (0.9%): one facial dysmorphia, one complex abnormal heart anatomy and one renal agenesia. CONCLUSION: Nuchal translucency (> 2.5 mm) is therefore a sonography sign associated with 7.4% of chromosomal anomalies. The distribution by size and mother ages is low. It should need superior larger-scale studies are needed for representative data. But this study shows that if fetal karyotype is normal, the incidence of congenital malformations seems to be the same by comparison with the general population.

First study of immunoglobulin and T cell receptor gene rearrangements in chronic and acute lymphoblastic leukemias from Tunisia.

We report the first characterization at the immunological and molecular level of 12 cases of chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia (ALL) from Tunisia. Our results show biallelic IgH gene rearrangement in B-CLL (6/6). A high ratio of T-ALL (4/6) was observed in Tunisian ALL leukemias. One T-ALL expressed CD10 (common ALL) which has already been found in some other cases of T-ALL. We report the occurrence of T cell receptor (TCR) beta and/or gamma gene rearrangements in two precursor B-ALL patients who had normally rearranged Ig genes. In one precursor B-ALL case, multiple rearranged IgH and TCR gamma bands allowed the identification of three clones. Such an oligoclonal ALL is interesting since only rare biclonal TCR beta or gamma gene rearrangements have been described.

Detoxification of aflatoxin-polluted peanut cakes with monomethylamine/Ca(OH)2: pilot industrial application, nutrition experiments, toxicity evaluation.

The process described has been studied up to an industrial pilot scale. In this article this article we summarize the basic knowledge on the process and the technological conditions of pilot application for detoxifying peanut cakes polluted by up to 3,500 ppb Aflatoxine (2,300 ppb B1). The nutritional experiments carried out on rats and other mammals are described, and the toxicological and biochemical evaluation of the cakes on Bacillacea are reported and discussed. The data collected show that the MMA/Ca(OH)2 process offers promising possibilities for industrial application on the basis of technological and economic criteria, as well as from the point of view of efficiency and safety.

Decontamination and detoxification of mycotoxins.

Product decontamination and chemical detoxification are needed because preventive measures are not fully able to avoid contamination by mycotoxins. Criteria for safety evaluation studies of decontaminated products have to be established. Few chemical methods are available on an industrial scale; among them, ammoniation and the mixture monomethylamine-calcium hydroxide treatments show greatest promise of short-term application to oilseed cakes. Technical, economic, and public health aspects of these treatments are considered. Other decontamination techniques are briefly reviewed.

Distribution of surgical hydatidosis in central Tunisia (1982-1985).

The mean annual surgical incidence rates (MASIR) of hydatidosis were measured for the 1982-1985 period in central Tunisia in order to investigate the natural history of human hydatidosis and provide baseline data for the evaluation of future prevention campaigns. 986 cases were identified from surgical records of regional hospitals to which cases from central Tunisia are mandatorily referred. The overall MASIR was 19.3 per 10(5) inhabitants. The MASIR according to district varied from 0 to 56.6 per 10(5), was higher in women than in men (22.6 versus 15.8 per 10(5] and increased with age (maximum 53.0 per 10(5) in the 50-59 age group for women and 27.1 per 10(5) in the 40-49 group for men). Among the 940 cases with single organ hydatidosis, liver ranged first (55.3%, 545/940), then lung (32.4% 320/940), kidney (2.7%) and spleen (1.8%). Among the 865 subjects with single lung or liver hydatidosis, liver was more often involved in women (349 out of 503) than in men (196 out of 362) (chi 2 = 20.9, p less than 0.001). In both sexes, the lung/liver ratio decreased with age. These data reveal the existence of highly endemic foci of hydatidosis within central Tunisia. The predominance of infection in women might be due to sex related behavioral differences. The causes of liver predominance in women and variation of lung/liver ratio are open to question.

[Epidemiology of hydatidosis in Tunisian children and adolescents]. / Epidémiologie de l'hydatidose chez l'enfant et l'adolescent tunisiens.

Analysis of the operative reports of hospitals in the central area of Tunisia allowed to define the epidemiology of echinococcosis in children and adolescents. Four hundred forty-three patients under 20 years of age were operated on between 1980 and 1985. In children less than 10 years of age, boys are more often concerned than girls, whereas prevalence in girls occurs after 10 years of age. Liver involvement is more frequent in girls, whatever their ages. Prevention programs should consider the high frequency in young children.

[Surgical incidence of hydatidosis in the Sahel and Central Tunisia]. / Incidence chirurgicale de l'hydatidose dans le Centre et le Sahel Tunisiens.

A retrospective hospital survey of patients having undergone surgery for hydatidosis was undertaken in order to evaluate hydatic endemicity in central Tunisia and the Sahel. The study made it possible to establish the following: an average prevalence of 22.8 cases per 100,000 inhabitants; a significant underregistration of the illness, only 51.5% of the cases being reported; certain high-risk rural areas are characterized by a prevalence exceeding 40 per 100,000 inhabitants; the disease is more frequent among women; surgical hydatidosis is not rare among the very young and the very old; among adults, the liver is the first organ affected, followed by the lungs; among children, it is the opposite. Hydatidosis thus represents a commonly-occurring disease that is frequently underestimated in official statistics. A preventive program must be conceived to control this scourge.

Seroepidemiology of hepatitis B in a population of children in central Tunisia.

The prevalence rate of HBV markers in the overall population was 18.0%. The prevalence rates of HBsAg and anti-HBs were 3.3% and 12.2% respectively. 2.5% of the children were negative for these markers but positive for anti-HBc alone. Of the 17 HBsAg positive children, 10 were HBeAg positive and four were anti-HBe positive. The statistical study using multifactorial correspondence analysis and the chi 2 test showed a positive relationship between the prevalence rate of anti-HBs and age, and a negative relationship between the prevalence rate of 'absence of markers' and age. The male sex and urban dwelling were related to higher prevalence rates of HBsAg and anti-HBc alone and to a lower prevalence rate of 'absence of markers'. No relationship was found between geographical zone, father's education and HBV markers. The implications of these results in terms of prevention are discussed.

[Cost of hydatidosis surgery at the Sousse University Hospital (Tunisia)]. / Coût de l'hydatidose chirurgicale à l'Hôpital universitaire de Sousse (Tunisie).

Hydatidosis is a very common disease in Tunisia, with a great economical importance for the health care system. In 1983, for Sousse Hospital, the total cost for hydatidosis was 125,000 US $. More than half of these costs were for "hospital days". A more rational in the services administration would make decrease these costs, but the best is a special attention to primary prevention.