Reversible biotinylation of C1q with a cleavable biotinyl derivative Application in C1q receptor (C1qR) purification

Reversible biotinylation of human C1q without impairment of its physiologic functions has allowed us to develop a simple and rapid purification method for C1q receptor (C1qR). The biotinylating reagent, NHS-SS-biotin (M_r 606.7) contains an extended connector or cross-linker arm which limits steric hindrance and is bridged by a cleavable disulfide bond to the biotin component. Biotinylation was achieved by mixing C1q (in PBS, pH 7.4) with NHS-SS-biotin (dissolved in dimethyl formamide) in a 50:1 v/v and 1:25 mol/mol ratio and allowing the reaction to continue at room temperature for 4 h. The mixture was then dialyzed against PBS pH 7.4 (2 × 1 liter) and analyzed by SDS-PAGE and hemolytic assay using C1q depleted serum. Under these conditions neither denaturation of the protein nor loss of hemolytic activity was evident. Such biotinylated C1q (Bio-C1q) was used to pull out the C1qR from detergent-solubilized (1% NP-40 in PBS, pH 7.4 plus inhibitors) ¹²⁵I-surface labeled membrane solution that had been first centrifuged (1 h, 45 000 × g, 4°C) and then sequentially precleared with immobilized protein A, protein A-IgG and gelatin. The mixture of Bio-C1q and membrane solution was then incubated (20 h, 4°C), applied to immobilized avidin (equilibrated with PBS, pH 7.4, 0.1% NP-40) and after washing, the bound C1qR was eluted with equilibrating buffer containing 1 M NaCl, and the C1q by same buffer containing 100 mM DTT. The eluted C1qR contained a major M_r 70 000 molecule which upon reduction electrophoresed with an apparent M_r of 85 000–90 000 as assessed by SDS-PAGE analysis. In addition, a faint single chain band of 30–40 kDa was eluted with the major band and may represent a non-covalently associated part of the C1qR molecule.     

Genetic characterization and progression of B3 measles genotype in Ethiopia: a study of five measles outbreak cases

BACKGROUND: One of the countries where measles remains endemic is Ethiopia. Previously, sequence data from Measles Viruses (MV) circulating in Ethiopia were obtained from clinical specimens. Now the Ethiopian Health and Nutrition Research Institute (ENHRI) has implemented cell culture techniques to isolate measles virus and molecular epidemiologic studies can be generated more easily. OBJECTIVE: To characterize the strains of Measles Virus circulating in Ethiopia during measles outbreaks in 2006 using viral isolates, and compare the results to previously identified Ethiopian strains. METHODS: A case study and convenience sampling method were conducted on five measles outbreak cases tb identify the circulating measles virus genotype in Addis Ababa and Amhara regions of Ethiopia in 2006. RESULTS: Three isolates were obtained from five specimens collected in two regions (1 from Amhara: Bahir Dar, and 2 from Addis Ababa: Addis Ketema and Kolefe Keranio subcities) in Ethiopia during 2006. The viral isolates were analyzed using standard genotyping protocols and were classified as genotype B3, identical to the strain circulating widely in West Africa and imported into Europe (Britain, Netherlands, Germany) and America (Mexico, USA, Canada). CONCLUSION: The conserved sequences among three isolates, covering a 3-month period, suggest that this B3 strain was circulating in Addis Ababa, Bahir Dar and possibly elsewhere in Ethiopia. To interrupt the transmission and circulation of MV, Ethiopia needs a strong national program of epidemiological surveillance, with characterization of circulating MV performed in a timely manner.     

International validation of the Chinese University Prognostic Index for staging of hepatocellular carcinoma:a joint United Kingdom and Hong Kong study

The outcome of hepatocellular carcinoma （HCC） patients significantly differs between western and eastern population centers. Our group previously developed and validated the Chinese University Prognostic Index （CUPI） for the prognostication of HCC among the Asian HCC patient population. In the current study, we aimed to validate the CUPI using an international cohort of patients with HCC and to compare the CUPI to two widely used staging systems, the Barcelona Clinic Liver Cancer （BCLC） classification and the Cancer of the Liver Italian Program （CLIP）. To accomplish this goal, two cohorts of patients were enrolled in the United Kingdom （UK; n = 567; 2006-2011） and Hong Kong （HK; n = 517; 2007-2012）. The baseline clinical data were recorded. The performances of the CUPI, BCLC, and CLIP were compared in terms of a concordance index （C-index） and were evaluated in subgroups of patients according to treatment intent. The results revealed that the median follow-up durations of the UK and HK cohorts were 27.9 and 29.8 months, respectively. The median overall survival of the UK and HK cohorts were 22.9 and 8.6 months, respectively. The CUPI stratified the patients in both cohorts into three risk subgroups corresponding to distinct outcomes. The median overall survival of the CUPI low-, intermediate-, and high-risk subgroups were 3.15, 1.24, and 0.29 years, respectively, in the UK cohort and were 2.07, 0.32, and 0.10 years, respectively, in the HK cohort. For the patients who underwent curative treatment, the prognostic performance did not differ between the three staging systems, and all were suboptimal. For those who underwent palliative treatment, the CUPI displayed the highest C-index, indicating that this staging system was the most informative for both cohorts. In conclusion, the CUPI is applicable to both western and eastern HCC patient populations. The performances of the three staging systems differed according to treatment intent, and the CUPI was demonstrated to be optimal for those     

The hazard of pregnancy loss and stillbirth among women in Kersa,East Ethiopia: A follow up study

BackgroundAlthough pregnancy loss causes considerable challenge to women’s health, population-based studies in rural areas are not widely available in low-income countries. This study aims to determine the hazard of pregnancy loss and related factors in the rural communities of Ethiopia.MethodologyA prospective community-based study was conducted over a period of 1 year. Pregnancy was identified as early as possible by a pregnancy urine test. All pregnant women identified during the screening were followed up at their home until termination of pregnancy or delivery of the neonate. The total follow-up time was 7802 ‘pregnant person months’. A Cox regression analysis was done to estimate the hazard of pregnancy loss.ResultOut of a total of 1438 terminated pregnancies, 143 (9.9%) did not end in live birth, 116 ended due to bleeding and 27 were stillbirths. Whilst the hazard of pregnancy loss was low among women with pregnancy interval of two or more years [AHR 0.3 (95% CI: 0.15, 0.43)], it was high among women having unplanned pregnancy [AHR 2.2 (95% CI: 1.56, 3.11)], among those who complained STI like symptoms during the index pregnancy [AHR 4.5 (95% CI: 2.79, 7.38)] and among those never received antenatal care [AHR 1.8 (95% CI: 1.13, 2.73)].ConclusionPregnancy loss was higher amongst women experienced unplanned pregnancy, complained STI like symptoms and women who had not attended antenatal care services.RecommendationTo reduce pregnancy loss in rural Ethiopia expanding and promoting the use of family planning, antenatal services and other reproductive health care is necessary.     

Human blood platelet gC1qR/p33

Platelets are involved in the development of many types of vascular lesions. In addition to their role in primary hemostasis, they participate in inflammatory processes that may contribute to the development of thrombosis, atherosclerosis and vasculitis. In this regard, we have been interested in platelet interactions with the complement subcomponent C1q. C1q has been shown to modulate platelet interactions with collagen and immune complexes, and has been identified at sites of vascular injury and inflammation, as well as in atherosclerotic lesions. Platelets express a variety of C1q binding sites, including gC1qR/p33 (gC1qR), a multifunctional, multicompartment cellular protein. Here we focus on the structure and function of platelet gC1qR and its emerging role in modulating platelet function at sites of vascular injury and inflammation. The authors are grateful to Wei‐Xing Guo M.D. for construction of the Exon 2 expression vector and GST‐E2 fusion protein expression, and to Yan Fang and Tara K. Murphy for technical assistance. This research was supported in part by grant HL50291 from the National Heart Lung and Blood Institute (EIBP, BG) and grant IM771 (BG) from the American Cancer Society.     

Effects of Ambient Air Pollutants on Asthma Medication Use and Wheezing among Fourth-Grade School Children from 12 Southern California Communities Enrolled in The Children's Health Study

To investigate the effects of 12 monthly average air pollution levels on monthly prevalence of respiratory morbidity, the authors examined retrospective questionnaire data on 2034 4th-grade children from 12 Southern California communities that were enrolled in The Children's Health Study. Wheezing during the spring and summer months was associated with community levels of airborne particulate matter with a diameter ≤ 10 μm (PM₁₀) (odds ratio (OR) = 2.91; 95% confidence interval (Cl) = 1.46–5.80), but was not associated with community levels of ozone, nitrogen dioxide, PM_2.5 (diameter ≤ 2.5), nitric acid, or formic acid. Logistic regression was performed on data stratified into two seasonal groups, spring/summer and fall/winter. Among asthmatics, the monthly prevalence of asthma medication use was associated with monthly levels of ozone, nitric acid, and acetic acid (OR = 1.80 [95%Cl = 1.19–2.70]; OR = 1.80 [95%Cl = 1.23–2.65]; OR = 1.57 [95% Cl = 1.11–2.21]; respectively). Asthma medication use was more prevalent among children who spent more time outdoors—with consequential exposure to ozone—than among children who spent more time indoors (OR = 3.07 [95%Cl = 1.61–5.86]; OR = 1.31 [95%Cl = 0.47–2.71]; respectively). The authors concluded that monthly variations in some ambient air pollutants were associated with monthly respiratory morbidity among school children.     

Dynamic stability control in forward falls: postural corrections after muscle fatigue in young and older adults

Many studies report that muscle strength loss may alter the human system’s capacity to generate rapid force for balance corrections after perturbations, leading to deficient recovery behaviours. Yet little is known regarding the effect of modifications in the neuromuscular system induced by fatigue on dynamic stability control during postural perturbations. This study investigates the effect of muscle strength decline induced by fatiguing contractions on the dynamic stability control of young and older adults during forward falls. Eleven young and eleven older male adults had to regain balance after sudden falls before and after submaximal fatiguing knee extension–flexion contractions. Young subjects had a higher margin of stability than older ones before and after the fatiguing task. This reflects their enhanced ability in using mechanisms for maintaining dynamic stability (i.e. a greater base of support). The margin of stability, the boundary of the base of support and the position of the extrapolated centre of mass, remained unaffected by the reduction in muscle strength induced by the fatiguing contractions, indicating an appropriate adjustment of the motor commands to compensate the deficit in muscle strength. Both young and older adults were able to counteract the decreased horizontal ground reaction forces after the fatiguing task by flexing their knee to a greater extent, leading to similar decreases in the horizontal velocity of centre of mass as in the pre fatigue condition. The results demonstrate the ability of the central nervous system to rapidly modify the execution of postural corrections including mechanisms for maintaining dynamic stability.     

Cockroach counts and house dust allergen concentrations after professional cockroach control and cleaning.

BACKGROUND: It is known that cockroach allergen exposure is both frequent in inner-city homes and associated with asthma severity in children living in those homes. However, there have been few studies of interventions to reduce exposures in this setting. OBJECTIVE: To evaluate the effect of short-term professional cockroach control and intensive cleaning on allergen concentrations. METHODS: Families of children from a school-based asthma treatment program who had skin test results positive to cockroach allergen were enrolled if the home had cockroaches. Forty-nine homes were randomly assigned to receive professional cleaning with bait traps containing insecticide, professional cleaning with bait traps without insecticide, or no cleaning or bait traps. In all homes, dust was collected repeatedly to evaluate cockroach allergen Bla g 2 in the kitchen and bedroom, and cockroaches were trapped and counted repeatedly for more than 11 weeks. RESULTS: Median cockroach counts were reduced in the homes treated with insecticide bait traps but not in other groups. There were significant reductions in allergen concentration in the kitchen in homes that received professional cleaning and had higher initial cockroach counts (54), regardless of whether bait traps had insecticide or not. CONCLUSIONS: We conclude that intensive cleaning can produce significant reductions in cockroach allergen in homes with heavy initial cockroach infestations.