Interferon modulates the leukotriene C4-induced non-adherence properties of leukocytes: acquisition of an asthmatic phenotype

We have previously shown that peripheral blood leukocytes (PBL) of asthmatic patients acquire non-adherence properties after challenge with leukotriene C4 (LTC4), whereas PBL of normal individuals do not. Hence the use of the LTC4-induced leukocyte-adherence-inhibition (LAI) assay enables one to recognise an asthmatic phenotype on the basis of the ability of PBL to respond in vitro to LTC4. To examine the possibility that alpha interferon (IFN alpha) may have relevance to the pathogenesis of bronchial asthma, various concentrations of IFN were incubated with normal PBL and the acquisition of non-adhering properties was measured. We found that following 24 h incubation with 500 U/ml IFN, normal PBL were induced to respond to a standard dose of LTC4, and this reaction was abrogated by FPL 55712 and cyclohexamide.     

Molecular epidemiology of cystic fibrosis in Tunisia

Cystic fibrosis is the most frequent autosomal recessive genetic disease in North European population. This pathology seems to not be rare in Tunisia. On another hand, development of molecular biology techniques has largely contributed to implement the study of the different mutations in the CFTR gene where over 1,300 mutations were reported. Herein, we describe the strategy used to detect molecular defects responsible of cystic fibrosis on 390 children (383 families) in Tunisian population. Several techniques were performed for genotype diagnosis: DNA extraction was from peripheral blood. Polymerase chain reaction (PCR) and polyacylamide gel electrophoresis, and reverse dot blot procedures were used to detect known point mutations. Denaturant gradient gel electrophoresis (DGGE) were used in a next step searching for the unknown point mutations that are later identified by automated sequencing on ABIprism 310. This strategy allowed us to detect 17 different mutations located on the different exons of the CFTR gene. The most frequent was the F508del (50.74%) followed by three other mutations (G542X, W1282X and N1303K) known to be common in the Mediterranean area. For mutations (T665S, 2766 del8, F1166C, L1043R) were exclusively found, up to now, in the Tunisian population. Our results permitted to establish cystic fibrosis mutations and their distribution in Tunisia and to implement an appropriate prevention program of these diseases through the genetic council and prenatal diagnosis.     

Prevalence of bacterial vaginosis in antenatal women

Bacterial vaginosis is an established risk factor in pregnant women for premature rupture of membranes and preterm delivery. This study was carried out to find out the prevalence of Bacterial Vaginosis (BV) in antenatal women with vaginal discharge and the effect of treatment with Metronidazole gel on pregnancy outcome. One hundred and fifty symptomatic and fifty asymptomatic women in second trimester of pregnancy in the age group of 20-30 years were included in the study. Gram stained smears of vaginal discharge were examined for evidence of BV with a scoring system by Nugent et al and was found to be positive in 38.5% in symptomatic antenatal women. Intravaginal metronidazole gel application was found to be an effective therapeutic option. Incidence of preterm labour was more in untreated cases.     

Identification and characterization of five novel MAN2B1 mutations in Italian patients with alpha-mannosidosis

Mutation analysis performed on six Italian families with alpha-mannosidosis type II allowed the identification of five new mutations in the MAN2B1 gene: c.157G>T, c.562C>T, c.599A>T, c.293dupA, c.2402G>A (p.E53X, p.R188X, p.H200L, p.Y99VfsX61, p.G801D). Protein residues G801 and H200 are conserved among the four mammalian alpha-mannosidases cloned to date: human, cattle, cat and mouse. In vitro expression studies demonstrated that both missense mutations expressed no residual alpha-mannosidase activity indicating that they are disease-causing mutations. Modelling into the three-dimensional structure revealed that the p.H200L could involve the catalytic mechanism, whereas p.G801D would affect the correct folding of the enzyme.     

Ketotifen, disodium cromoglycate, and verapamil inhibit leukotriene activity: determination by tube leukocyte adherence inhibition assay

Peripheral blood leukocytes (PBL) from asthmatic individuals lose their former ability to adhere to glass when incubated with leukotriene C4 (LTC4). A modified leukotriene-induced leukocyte adherence inhibition (LAI) assay was therefore used to study the ability of anti-asthmatic drugs to abrogate such activity. Ketotifen, disodium cromoglycate, Verapamil, and dimethpyridene, all at concentrations of 2 X 10(-6) M, were co-cultured with 2 X 10(-7) M LTC4 and their effect on the LTC4-induced LAI determined. Verapamil, Ketotifen, and disodium cromoglycate all inhibited the LTC4 activity while the H1 antagonist, dimethpyridene, did not. These results suggest that the beneficial effect of Verapamil, Ketotifen, and disodium cromoglycate in bronchial asthma is probably as calcium antagonists that cause the inhibition of leukotriene activity.     

Optimization of risk stratification for anticoagulation-associated intracerebral hemorrhage: net risk estimation

Journal of Neurology - Every anticoagulation decision has in inherent risk of hemorrhage; intracerebral hemorrhage (ICH) is the most devastating hemorrhagic complication. We examined whether...     

Investigation of the adsorption properties of gemcitabine anticancer drug with metal-doped boron nitride fullerenes as a drug-delivery carrier: a DFT study

Anticancer-drug delivery is now becoming a challenging approach for researchers as it allows controlled drug delivery near cancerous cells with minimized generic collection and the avoidance of secondary side effects. Hence in this work, the applications of nanostructures as anticancer drug-delivery carriers were widely investigated to target cancerous tissues. Based on DFT calculations, we investigated the transition metal-doped boron nitride nanostructure as a drug-delivery agent for the gemcitabine drug utilizing the B3LYP/6-31G (d, p) level of theory. In this research, the adsorption energy and electronic parameters of gemcitabine on the interaction with the metal-doped BN nanostructures were studied. It has been observed that metal doping significantly enhances the drug-delivery properties of BN nanostructures. Among the investigated nanostructures, Ni–BN has been found to be the most prominent nanostructure to transport gemcitabine with an elevated value of adsorption energy in both the gas phase (−45.79) and water media (−32.46). The interaction between gemcitabine and BN nanostructures was confirmed through frontier molecular orbitals and stabilization energy analysis. The fractional charge transfer, MEP, NCI, and NBO analyses exposed the charge transfer from drug molecule to the BN nanostructures. Transition density maps and UV-VIS spectra were also plotted to investigate the excited-state properties of the designed complexes. Thus, the present study provides an in-depth interaction mechanism of the gemcitabine drug with BN, which reveals that metal-doped BN nanostructures can be a favorable drug-delivery vehicle for the gemcitabine anticancer drug.

Anticancer-drug delivery is now becoming a challenging approach for researchers as it allows controlled drug delivery near cancerous cells with minimized generic collection and the avoidance of secondary side effects.     

Allergen-specific leukocyte adherence inhibition (LAI) assay: sensitivity, specificity and mechanism

An allergen-specific tube leukocyte adherence inhibition (LAI) assay has been developed in order to study the mechanism by which leukocytes lose their normal property of adherence to glass. Peripheral blood leukocytes (PBL) from 27 individuals allergic to Dermatophagoides farinae (DF), 10 with seasonal rhinitis not induced by DF and 49 non-allergic healthy volunteers were challenged in vitro with DF and a non-relevant allergen, Artemisia vulgaris (AV) and then assayed for the ability to adhere to glass tubes. Challenge by DF, but not by AV, resulted in loss of adherence by PBL from patients allergic to DF, but not in those of normal controls. The specific LAI response was dose-dependent and occurred only when a critical dose of 0.5 X 10(3) was employed. Following in vitro challenge with DF, radio-immunoassay using an antiserum to LTC4 detected immunoreactive material in supernatants of PBL from DF-allergic individuals. When highly enriched mononuclear cells from non-allergic individuals were armed with cytophilic allergen-specific IgE and challenged with the specific allergen, they lost the property of glass adherence and released a substance that was immunoreactive with LTC4. The results suggest that the chain of events leading to the LAI response in PBL from allergic individuals involves primary recognition of the allergen by specific IgE antibodies bound to receptors on mononuclear cells. The cells are thus triggered to synthesize cysteinyl-containing leukotrienes which mediate the LAI phenomenon. The results suggest that this assay may be used to study allergen-antibody interaction and the subsequent events leading to the clinical picture of atopic diseases.     

Correlates of Pancreatic Enzyme Replacement Therapy Intake in Adults with Cystic Fibrosis: Results of a Cross-Sectional Study

Most people with cystic fibrosis (pwCF) develop pancreatic insufficiency and are treated with pancreatic enzyme replacement therapy (PERT). We aimed to describe the use of PERT and assess the correlates of PERT dose in adult pwCF. In a cross-sectional study at the Copenhagen CF Centre, the participants reported PERT intake, gastrointestinal (GI) symptoms and the use of concomitant treatments. Demographic and clinical characteristics were extracted from the Danish CF Registry. We used linear regression to assess the correlates of PERT dose per kg bodyweight (U-lipase/kg). We included 120 pwCF with a median age of 32.9 years, 46% women and 72% F508delta homozygote. The PERT dose ranged from 0 to 6160 U-lipase/kg per main meal (mean 1828; SD 1115). The PERT dose was associated with participants’ sex (men vs. women: 661; 95% CI: 302; 1020 U-lipase/kg), age (−16; 95% CI: −31; −1 U-lipase/kg per year) and weight (−45; 95% CI: −58; −31 U-lipase/kg per kg). Having less frequent constipation and being lung transplanted were also associated with a higher PERT dose. A third of participants did not take PERT for snacks, and this was associated with the frequency of diarrhoea. These findings indicate that PERT intake may be improved to reduce GI symptoms.