N-glycosylation of murine IFN-beta in a putative receptor-binding region.

Human and mouse genomes contain more than 20 related genes encoding diverse type I interferons (IFNs- alpha/beta), cytokines that are crucial for resistance of organisms against viral infections. Although the amino acid sequences of various IFN-alpha/beta subtypes differ markedly, they are all considered to share a common three-dimensional structure and to bind the same heterodimeric receptor, composed of the IFNAR-1 and IFNAR-2 subunits. Analysis of available mammalian IFN-beta sequences showed that they all carry 1 to 5 predicted N-glycosylation sites. Murine IFN-beta contains three predicted N-glycosylation sites (Asn29, Asn69, Asn76), one of which (Asn29) is located in the AB loop, in a region predicted to interact with the type I IFN receptor. The aim of this work was to test if this site is indeed N-glycosylated and if this glycosylation would affect IFN antiviral activity. We showed that all three N-glycosylation sites predicted from the sequence, including Asn29, carry N-linked sugars. Mutation of individual N-glycosylation sites had a weak negative influence on IFN antiviral activity. In contrast, the complete loss of glycosylation dramatically decreased activity. Our data suggest that interaction of murine IFN-beta with the IFNAR could locally differ from that of human IFN-alpha2 and human IFN-beta.     

Effects of an anti-interleuktn-6 (IL-6) murine monoclonal antibody in a patient with acute monoblastic leukemia

Because IL-6 has been involved in the pathogenesis of acute monoblastic leukemia, we investigated thein vitro anti-proliferative effect and thein vivo anti-tumoral effect of an anti-IL-6 murine monoclonal antibody (mAb) in a patient with MSB type acute leukemia. In the current study, we clearly show the IL-6 dependence of monoblastic cell viability and proliferationin vitro in short-term cultures of malignant cells and the clinical activity of the anti-IL-6 murine mAb. The complete neutralization of IL-6in vivo was associated with a transient but complete disappearance of malignant monoblastic cells in the peripheral blood, with improvement or even normalization of several other biological parameters of disease activity, No immunization against the anti-IL-6 murine mAb was observed.     

Persistent central diabetes insipidus in a very low birth weight infant]

Central diabetes insipidus (DI) is extremely rare during the neonatal period. Most cases of central DI are secondary to a known aetiology. Substitutive treatment with desmopressin is effective with nasal or oral preparation, but doses are variable and must be tailored individually. We report on a case in a very low birth weight infant with an idiopathic central DI during the first month of life. He was successfully treated with oral desmopressin. The treatment was maintained after discharge with low doses desmospressin.     

Perception and social consequences of tuberculosis: A focus group study of tuberculosis patients in Sialkot, Pakistan

Treatment defaulting is one of the major causes of the failure of TB control programs. In Bethania Hospital. Sialkot, defaulting rates are high: 72% for the standard 12 months course and 56% for the 8 months course. Attrition is especially important in the first weeks of treatment: < 70% of the patients start the 10th week of treatment. A focus group discussion study has been carried out to gain a better understanding of the impact of social stigmatization, treatment cost and pregnancy on defaulting. The study population consisted of 3 male and 3 female groups each with 8 hospitalized TB patients. The study shows that TB is perceived as a very dangerous, infectious and incurable disease. This perception has many social consequences: stigmatization and social isolation of TB patients and their families; diminished marriage prospects for young TB patients, and even for their family members; TB in one of the partners may lead to divorce. Due to fear patients often deny the diagnosis and reject the treatment. While both male and female TB patients face many social and economical problems, female patients are more affected. Divorce and broken engagements seem to occur more often in female patients. Females are usually economically dependent on their husbands and family in law, and need their cooperation to avail of treatment. The belief that pregnancy enhances the risk for relapse decreases their marriage prospects. Pregnancy is also a reason for stopping TB treatment as both are considered as incompatible. The findings of this study reveal the urgent need for a health education campaign to convince the general population that tuberculosis is curable. All health care providers should act as destigmatizers.     

The deltoid muscle: an electromyographical analysis of its activity in arm abduction in various body postures

Summary We have carried out an electromyographical examination of the activity of five different regions of the deltoid muscle during abduction/adduction in various body postures with different biomechanical actions of arm gravity. The results show that the deltoid action is highly differentiated in its different regions and is not restricted only to the generation of an abducting moment in the shoulder joint. There is obviously a biomechanical contribution, mainly by its spinal and clavicular regions, to the stabilization of the glenohumeral joint and to the control of the selected plane of abduction.

---

Résumé Nous avons réalisé l'examen électromyographique de l'activité de cinq régions différentes du muscle deltoïde pendant les mouvements d'abduction-adduction, dans diverses positions du corps correspondant à des effets biomécaniques différents du poids du membre supérieur. Les résultats montrent que cette activité est très différenciée dans les diverses régions du muscle et qu'elle ne se laisse pas expliquer par la seule production d'un mouvement d'abduction au niveau de l'épaule. Il existe manifestement une contribution biomécanique des parties antérieure et postérieure du deltoïde surtout dans la stabilisation de l'articulation et le contrôle du plan d'abduction.

---

---

Supported by the ASIF-Foundation, Switzerland     

Individual chaperones required for Yop secretion by Yersinia.

Pathogenic yersiniae secrete anti-host proteins called Yops, by a recently discovered Sec-independent pathway. The Yops do not have a classical signal peptide at their N terminus and they are not processed during membrane translocation. The secretion domain is nevertheless contained in their N-terminal part but these domains do not resemble each other in the different Yops. We have previously shown that YopE secretion requires SycE, a 15-kDa acidic protein acting as a specific cytosolic chaperone. Here we show that the gene downstream from yopH encodes a 16-kDa acidic protein that binds to hybrid proteins made of the N-terminal part of YopH and either the bacterial alkaline phosphatase or the cholera toxin B subunit. Loss of this protein by mutagenesis led to accumulation of YopH in the cytoplasm and to a severe and selective reduction of YopH secretion. This protein thus behaves like the counterpart of SycE and we called it SycH. We also engineered a mutation in lcrH, the gene upstream from yopB and yopD, known to encode a 19-kDa acidic protein. Although this mutation was nonpolar, the mutant no longer secreted YopB and YopD. The product of lcrH could be immunoprecipitated together with cytoplasmic YopD. lcrH therefore seems to encode a YopD-specific chaperone, which we called SycD. Determination of the dependence of YopB on SycD requires further investigation. SycE, SycH, and SycD appear to be members of a new family of cytosolic chaperones required for Yop secretion.     

Nosocomial viral infections in a pediatric service: example of rotaviral gastroenteritis and respiratory syncytial viral bronchiolitis]

Nosocomial infections are a preoccupation in a pediatric hospital mainly during the winter with bronchiolitis and gastroenteritis epidemics. We have examined the risk factors of nosocomial infections. MATERIAL AND METHODS: A prospective study was conducted between November, 1999 and March, 2000 in the infants units of the Le Havre hospital. We systematically listed the admissions and contacted the family after their discharge by phone. A geographic information system was implemented to display the epidemiological data; this software is able to illustrate the sectors at risk. RESULTS: During the study, 687 infants were hospitalized of whom 458 for bronchiolitis and community-acquired gastroenteritis. Mean age was 5.4 months old. No nosocomial bronchiolitis occurred. Prevalence of nosocomial gastroenteritis was 10% (68 cases including nine after discharge). Infants with nosocomial infection were younger than those with community-acquired infection (6.6 months vs. 11.2 months, P < 0.01). The mean length of stay was longer in nosocomial infection (7.7 vs. 4.1 days, P < 0.05). Among the infants with bronchiolitis, 16% have developed nosocomial intestinal infections (RR = 2.65, IC: 1.59-4.4; P < 0.01). The geographic analysis pointed the area with nosocomial risk (bedroom without water, nearness of nurse office and games room). CONCLUSION: Geographic information system is a part of the quality control system and may have some interaction effect on final decision making. Incidence of nosocomial infections showed the need for a prevention strategy in a pediatric hospital.     

Contribution of neo-electroencephalography in adult functional and psychiatric disorders]

Two comparative studies of the basic activity at rest, with closed eyes taken in conventional EEG and analysed in Neo-EEG are carried out in adults showing functional or psychiatric disorders. The first open study involves 18 subjects suffering from a affection called "neurodystony" and 24 depressed subjects. The second study made in double-blind compares the results of the conventional EEG with the Neo-EEG in 19 depressed patients, 28 alcoholic patients and 26 psychotic patients. The Neo-EEG discloses abnormalities in about 60% of the cases when the conventional EEG is normal. The conventional EEG as well as the Neo-EEG diagnose a greater number of low voltage in alcoholic subjects and clear abnormalities in psychotic subjects. Low voltage is never detected in psychotic patients. In depressives, the Neo-EEG shows about 65% of abnormalities of which an asymmetry of the basic frequency in the center of the two hemispheres when they are analysed separately. That asymmetry develops in parallel with the clinical state. The asymmetry is also found in psychotic patients. In nervous or neurodystonic subjects, the Neo-EEG only discloses 25% of abnormalities. The Neo-EEG appears as an easy method, able to detect dysfunctions which cannot be disclosed with the conventional EEG and useful to follow their developments. Moreover, the result of this technique brings to the fore abnormalities not detected with the conventional EEG: this eventually leads to prescribe other therapies than those initially considered.     

Adenoviral vectors expressing siRNAs for discovery and validation of gene function

RNA interference is a powerful tool for studying gene function and for drug target discovery in diverse organisms and cell types. In mammalian systems, small interfering RNAs (siRNAs), or DNA plasmids expressing these siRNAs, have been used to down-modulate gene expression. However, inefficient transfection protocols, in particular, for primary cell types, have hampered the use of these tools in disease-relevant cellular assays. To be able to use this technology for genome-wide function screening, a more robust transduction protocol, resulting in a longer duration of the knock-down effect, is required. Here, we describe the validation of adenoviral vectors that express hairpin RNAs that are further processed to siRNAs. Infection of cell lines, or primary human cells, with these viruses leads to an efficient, sequence-specific, and prolonged reduction of the corresponding target mRNA, resulting in a reduction of the encoded protein level in the cell. For knock-down of one of the targets, GalphaS, we have measured inhibition of ligand-dependent, G-protein-coupled signaling. It is expected that this technology will prove to be of great value in target validation and target discovery efforts.