The Difficult Case of Crystallization and Structure Solution for the ParC55 Breakage-Reunion Domain of Topoisomerase IV from Streptococcus pneumoniae

BACKGROUND: Streptococcus pneumoniae is the major cause of community-acquired pneumonia and is also associated with bronchitis, meningitis, otitis and sinusitis. The emergence and increasing prevalence of resistance to penicillin and other antibiotics has led to interest in other anti-pneumonococcal drugs such as quinolones that target the enzymes DNA gyrase and topoisomerase IV. During crystallization and in the avenues to finding a method to determine phases for the structure of the ParC55 breakage-reunion domain of topoisomerase IV from Streptococcus pneumoniae, obstacles were faced at each stage of the process. These problems included: majority of the crystals being twinned, either non-diffracting or exhibiting a high mosaic spread. The crystals, which were grown under conditions that favoured diffraction, were difficult to flash-freeze without loosing diffraction. The initial structure solution by molecular replacement failed and the approach proved to be unviable due to the complexity of the problem. In the end the successful structure solution required an in-depth data analysis and a very detailed molecular replacement search. METHODOLOGY/PRINCIPAL FINDINGS: Crystal anti-twinning agents have been tested and two different methods of flash freezing have been compared. The fragility of the crystals did not allow the usual method of transferring the crystals into the heavy atom solution. Consequently, it was necessary to co-crystallize in the presence of the heavy atom compound. The multiple isomorphous replacement approach was unsuccessful because the 7 cysteine mutants which were engineered could not be successfully derivatized. Ultimately, molecular replacement was used to solve the structure by sorting through a large number of solutions in space group P1 using CNS. CONCLUSIONS/SIGNIFICANCE: The main objective of this paper is to describe the obstacles which were faced and overcome in order to acquire data sets on such difficult crystals and determine phases for successful structure solution

Body mass index variations among adolescents from Kano Metropolis, Nigeria

Bodyweight and height measurements were carried out on 2, 100 healthy teenagers (1050 males and 1050 females) randomly selected in Kano metropolis. These measurements were used to calculate Body Mass Index (BMI) according to the formula weight (kg)/height2 (m). Mean BMI values increased with age in the subjects irrespective of sex. However, female subjects had higher mean BMI values than their male counterparts in all the age groups. Mean BMI values ranged from 17.0 to 20.9 in males and from 18.0 to 24.0 in females. These BMI ranges of values were used as the basis for classification of the subjects as underweight, normal and overweight. Key words: adolescence, body mass index, anthropometric assessment, nutritional statu

Refusing to Endorse. A must Explanation for Pejoratives.

In her analysis of pejoratives, Eva Picardi rejects a too sharp separation between descriptive and expressive content. I reconstruct some of her arguments, endorsing Eva’s criticism of Williamson’s analysis of Dummett and developing a suggestion by Manuel Garcia Carpintero on a speech act analysis of pejoratives. Eva’s main concern is accounting for our instinctive refusal to endorse an assertion containing pejoratives because it suggests a picture of reality we do not share. Her stance might be further developed claiming that uses of pejoratives not only suggest, but also promote a wrong picture of reality. Our refusal to endorse implies rejecting not only a wrong picture of reality but also a call for participation to what that picture promotes

Directional Distributions in Tracking of Space Debris

Directional distributions play an important role in describing uncertainty in spherical coordinates. A review is given of some standard distributions on the sphere which arise as special cases of the Fisher-Bingham distribution. A new distribution, called the “extreme FB5” istribution, is introduced to describe semi-concentrated behavior on the sphere, that is, patterns of data that are unimodal and concentrated near a great circle. This behavior is particularly relevant to tracking problems. Properties of the new distribution are discussed and methods are given for simulation and estimation. Two simple error propagation illustrations are given to demonstrate the usefulness of the new model

Analogue circuit realisation of surface-confined redox reaction kinetics

The literature on voltammetry and electrochemical impedance spectroscopy (EIS) recognises the importance of using large-amplitude sinusoidal perturbations to better characterise electrochemical systems. To identify the parameters of a given reaction, various electrochemical models with different sets of values are simulated and compared against the experimental data to determine the best-fit set of parameters. However, the process of solving these nonlinear models is computationally expensive. This paper proposes analogue circuit elements for synthesising surface-confined electrochemical kinetics at the electrode interface. The resultant analogue model could be used as a solver to compute reaction parameters as well as a tracker for ideal biosensor behaviour. The performance of the analogue model was verified against numerical solutions to theoretical and experimental electrochemical models. Results show that the proposed analogue model has a high accuracy of at least 97% and a wide bandwidth of up to 2 kHz. The circuit consumed an average power of 9 μW

The relationship between serum bilirubin level with interleukin.6, interleukin.10 and mortality scores in patients with sepsis

Context: Bilirubin has been shown to influence the mechanisms of both apoptosis and inflammation.Aims: The aim of the following study is to investigate the relationship between the serum bilirubin level with sepsis progression.Settings and Design: A total of 20 patients from intensive care unit were included for this study.Materials and Methods: Patients were divided into two groups: Patients diagnosed with sepsis according to the American College of Chest  Physicians/Society of Clinical Care Medicine consensus conference criteria (n = 10) and patients treated for various other diagnoses (n = 10). Blood samples were collected for both groups at the time of origin (defined as the time of diagnosis) and 24 and 48 h after diagnosis. Serum interleukin (IL).6, IL.10 and bilirubin levels were analyzed and compared. Acute physiology and chronic health evaluation (APACHE) II and sepsis related organ failure (SOFA) scores of the patients were also evaluated. Statistical Analysis Used: We used Statistical Package for Social Sciences (SPSS for Windows, version 17.0, SPSS Inc. 233 South Wacker Drive, Chicago) for statistical analysis.Results: At all.time intervals, serum IL.6, IL.10 and total, direct and  indirect serum bilirubin levels were significantly higher in the sepsis group (P < 0.05); APACHE II and SOFA scores were also significantly higher. Both SOFA scores and serum IL.10 levels were positively correlated with bilirubin levels 24 h after diagnosis (P < 0.05, r = .0.76).Conclusions: Although levels of bilirubin and other associated parameters were higher for the sepsis group, only SOFA score and bilirubin levels were correlated. Because bilirubin is already a SOFA parameter, this correlation was not considered as clinically significant.Key words: Acute physiology and chronic health evaluation, bilirubin, interleukin.6, interleukin.10, sepsi

Adaptive Reconfiguration of Natural Killer Cells in HIV-1 Infection

Human cytomegalovirus (HCMV) co-infection is highly prevalent within HIV-1 cohorts and is an important cofactor in driving ongoing immune activation, even during effective antiretroviral treatment. HCMV infection has recently been associated with expansion of adaptive-like natural killer (NK) cells, which harbor epigenetic alterations that impact on their cellular function and phenotype. The influence of HCMV co-infection on the considerable heterogeneity among NK cells and their functional responses to different stimuli was assessed in a cohort of HIV-1-infected individuals sampled during different stages of infection, compared with healthy subjects stratified according to HCMV serostatus. Our data demonstrate a reshaping of the NK cell pool in HIV-1 infection of HCMV-seropositive individuals, with an accentuated peripheral transition of CD56dim NK cells toward a mature CD57+ CD85j+ NKG2C+ NKG2A− phenotype. Lack of PLZF further distinguishes adaptive NK cells from other NK cells expressing CD57 or NKG2C. PLZF− NK cells from HIV-infected individuals had high expression of CD2, were Siglec-7 negative and exhibited downregulation of key signaling molecules, SYK and FcεRI-γ, overwhelmingly displaying features of adaptive NK cells that correlated with HCMV serum Ab levels. Notably this adaptive-like signature was detected during early HIV-1 infection and persisted during treatment. Adaptive-like NK cell subsets in HIV-1-infected individuals displayed enhanced IFN-γ production following Fc receptor triggering compared with their conventional NK cell counterparts, and their ability to produce TNF-α and degranulate was preserved. Together, these data suggest that HMCV infection/reactivation, a hallmark of HIV-1 infection, plays a role in driving a relative expansion of NK cells with adaptive features during HIV-1 infection. The identification of selective NK subsets with retained effector activity in HIV-1-infected subjects raises the possibility of developing therapeutic strategies that exploit specific NK subpopulations to achieve better HIV-1 control

Efficacy of Parazoquantel against Schistosoma Heamatobium Enfection among Residents of Wasai Dam in Minjibir Local Government, Kano State, Nigeria

Schistosomiasis is a chronic debilitating infection due to Schistosoma species belonging to parasitic trematode worms. It continues to threaten millions of people, particularly the rural poor in the developing countries. A study was carried out to determine the prevalence of urinary Schistosomiasis among dwellers of Wasai dam in Minjibir, Kano State and to evaluate efficacy of single dose of Parazoquantel. A total of 402 people in four selected villages residing around the study area were screened for the present or absence of Shistosoma haematobium ova and efficacy of single dose Parazoquantel was evaluated. Eggs of S. haematobium were examined using urine concentration sedimentation technique. The overall prevalence of the infection was 61.9% and Mean Eggs Per cubic Centilitre (EPC) of 31.8% were recorded. Males were more infected (67.9%) than females (54.8%). Cure rate in the present study was 97.9%. There was significant difference between mean EPC and cure rate (p<0.05). This study concludes that Parazoquantel is still highly efficacious at a single dose for the treatment of S. haematobium infection.Keywords: Parazoquantel, therapy, Schistosomiasis, Wasai, Dam, Kano-Nigeria

Comparison of fluorgestone and medroxyprogesterone intravaginal sponges for oestrus synchronization in Saanen does during the transition period

The efficiency of medroxyprogesterone acetate (MAP) and fluorogestone acetate (FGA) sponges for synchronizing oestrus in lactating Saanen goats was investigated during the transition from non-breeding to natural breeding season. Does were treated for 11 days with 60 mg MAP (n=19) or 40 mg FGA (n=24) sponges. All does received intramuscular injections of 750 IU pregnant mare serum gonadotrophin (PMSG) and 125 mg cloprostenol (PGF2a) 48 h prior to sponge removal. Cervical artificial insemination (AI) with fresh diluted semen was performed at a fixed time (36 and 48 h) followed progestagen withdrawal. The two progestagen treatments showed no significant difference in oestrous response (100% both for MAP and FGA groups), time to the onset (15.8+09 and 15.0+06 h for the MAP and FGA groups, respectively), duration (30.5+1.9 and 34.0+1.4 h for MAP and FGA, respectively) and cessation (42.32+1.6 and 43.25+1.3 h for MAP and FGA, respectively) of the induced oestrus period. No significant difference was observed with respect to pregnancy rates determined at the 53rd day after AI (52.6 and 50.0% for MAP and FGA, respectively). These dates indicate that the use of MAP and FGA intravaginal progestagen treatments are equally efficient in synchronizing oestrus in lactating goats during the transition from the non-breeding to the natural breeding season. Key Words: Goat, Oestrus, Synchronization, Medroxyprogesterone acetate, MAP, Fluorogestone acetate, FGA SA Jnl Animal Sci Vol.34(1) 2004: 18-2

Comparison of anaesthetic cost in open and laparoscopic appendectomy

Context: Appendectomy is generally conducted as open or by laparoscopic surgical techniques under general anesthesia.Aims: This study aims to compare the anesthetic costs of the patients, who underwent open or laparoscopicappendectomy under general anesthesia.Settings and Design: The design is retrospective and records of 379 patients who underwent open or laparoscopicappendectomy under general anesthesia, falling under the category of I‑III risk group according to the American Societyof Anesthesiologists (ASA) classification between the years 2011 and 2013, and aged 18-77.Subjects and Methods: Open (Group I) or laparoscopic (Group II) appendectomy operation under general anesthesiawere evaluated retrospectively by utilizing hospital automation and anesthesia observation records. This study evaluatedthe anesthesia time of the patients and total costs (Turkish Lira ₺, US dollar $) of anesthetic agents used (induction,maintenance), necessary medical materials (connecting line, endotracheal tube, airway, humidifier, branule, aspirationprobe), and intravenously administered fluids were evaluated.Statistical Analysis Used: We used Statistical Package for the Social Sciences software (SPSS version 17.0) forstatistical analysis.Results: Of the patients, 237 were males (62.53$) in Group I and 83.09 ± 26.85₺ (41.29 ± 13.34$) inGroup II (P > 0.05). A correlation was observed between cost and operation times (P = 0.002, r = 0.158).Conclusions: Although a statistical difference was not established in this study in terms of time and costs inappendectomy operations conducted as open and laparoscopically, changes may occur in time in market conditionsof drugs, patent rights, legal regulations, and prices. Therefore, we believe that it would be beneficial to update andrevise cost analyses from time to time.Keywords: Cost, cost comparison laparoscopic appendectomy, open appendectom