A theoretical study of the hydrolysis mechanism of A-234; the suspected novichok agent in the Skripal attack

A-234, [EtO–P( O)(F)–N C(Me)–N(Et)₂], is the suspected A-type nerve agent used in the Skripal attack on the 4th of March 2018. Studies related to the structure and reactivity of this compound are limited. We, therefore, aimed at understanding the underlying hydrolysis mechanism of A-234 within the DFT framework. The attack of the water molecule can occur at the phosphinate and acetoamidine reactive centres. Our theoretical findings indicate that the hydrolysis at the acetoamidine centre is thermodynamically favoured compared to the hydrolysis at the phosphinate centre. The hydrolysis at the acetoamidine moiety may proceed via two pathways, depending on the nitrogen atom participating in the hydrolysis. The main pathway consists of four distinct channels to reach the final product, with the concerted 1,3-proton shift favoured kinetically and thermodynamically in the gas phase and water as solvent. The results are in good agreement with the literature, although some differences in the reaction mechanism were observed.

A theoretical study of the hydrolysis mechanism of A-234 [EtO–P( O)(F)–N C(Me)–N(Et)₂]; the suspected novichok agent in the Skripal attack.     

Changes in healthy elderly women's physical performance: a 3-year follow-up

Background

Inflammatory states, hypovitaminosis D and secondary hyperparathyroidism may have a role in the age-related loss of muscle mass, and physical performance in healthy old people. The aim of this study is to investigate changes in muscle mass, strength and physical performance in healthy, active elderly females over a 3-year follow-up, correlating them with any inflammatory states and PTH and 25-hydroxyvitamin D (25-OHD) levels.

Methods

One hundred healthy females over 65 years of age routinely attending a twice-weekly mild fitness program were eligible for the study. Clinical history, serum parameters, body composition by DEXA, handgrip strength, knee extensor isometric/isotonic strength and functional performance measured using the Short Physical Performance Battery (SPPB) were evaluated at the baseline and after 3 years.

Results

After 3 years, the women had a significant decrease in weight (?:−0.8 ± 3.1 kg; p < 0.05) and height (?:−0.4 ± 0,6 cm; p < 0.001), while their BMI and body composition parameters did not change. Only IL-6 (?: 0.6 ± 2.0; p < 0.01) and PTH (?: 30.7 ± 29.2 ng/L; p < 0.001) increased significantly, while there were no changes in 25-OHD levels. There was a significant decrease in all the SPPB results and in muscle strength. ? PTH only correlated with the variation in 4-meter walking speed (r: 0.41; p < 0.01).

Conclusions

With advancing age, physical performance declines even in healthy, active females despite a spare of muscle mass. The increase in PTH seems to have a role in this decline, that could be clarified by further investigations.     

Gene-expression profiling and not immunophenotypic algorithms predicts prognosis in patients with diffuse large B-cell lymphoma treated with immunochemotherapy

Diffuse large B-cell lymphomas (DLBCLs) can be divided into germinal-center B cell-like (GCB) and activated-B cell-like (ABC) subtypes by gene-expression profiling (GEP), with the latter showing a poorer outcome. Although this classification can be mimicked by different immunostaining algorithms, their reliability is the object of controversy. We constructed tissue microarrays with samples of 157 DLBCL patients homogeneously treated with immunochemotherapy to apply the following algorithms: Colomo (MUM1/IRF4, CD10, and BCL6 antigens), Hans (CD10, BCL6, and MUM1/IRF4), Muris (CD10 and MUM1/IRF4 plus BCL2), Choi (GCET1, MUM1/IRF4, CD10, FOXP1, and BCL6), and Tally (CD10, GCET1, MUM1/IRF4, FOXP1, and LMO2). GEP information was available in 62 cases. The proportion of misclassified cases by immunohistochemistry compared with GEP was higher when defining the GCB subset: 41%, 48%, 30%, 60%, and 40% for Colomo, Hans, Muris, Choi, and Tally, respectively. Whereas the GEP groups showed significantly different 5-year progression-free survival (76% vs 31% for GCB and activated DLBCL) and overall survival (80% vs 45%), none of the immunostaining algorithms was able to retain the prognostic impact of the groups (GCB vs non-GCB). In conclusion, stratification based on immunostaining algorithms should be used with caution in guiding therapy, even in clinical trials.     

Detection of Metachronous Neoplasms in Colorectal Cancer Patients: Identification of Risk Factors

Purpose Patients with colorectal cancer have a high risk of developing metachronous neoplasms. Identification of predictive factors associated with such conditions would allow individualized follow-up strategies in these patients. This study was designed to identify individual and familial factors associated with the development of metachronous colorectal neoplasms in patients with colorectal cancer. Methods In the context of a prospective, multicenter, general population-based study—the EPICOLON project—all patients with colorectal cancer attended in ten Spanish hospitals during a one-year period were included. Patients with familial adenomatous polyposis or inflammatory bowel disease were excluded. All patients were monitored by colonoscopy within two years of the diagnoses. Demographic, clinical, pathologic, molecular (microsatellite instability status and immunohistochemistry for MSH2 and MLH1), and familial characteristics (fulfillment of Amsterdam I or II criteria, and revised Bethesda guidelines) were analyzed. Results A total of 353 patients were included in the study. At two years of follow-up, colonoscopy revealed the presence of adenomas in 89 (25 percent) patients and colorectal cancer in 14 (3.9 percent) patients, in 7 cases restricted to anastomosis. Univariate analysis demonstrated that development of metachronous neoplasm (adenoma or colorectal cancer) was associated with personal history of previous colorectal cancer (odds ratio, 5.58; 95 percent confidence interval, 1.01–31.01), and presence of previous or synchronous adenomas (odds ratio, 1.77; 95 percent confidence interval, 1.21–3.17). Although nonstatistical significance was achieved, metachronisms were associated with gender (P < 0.09) and differentiation degree (P < 0.08). Multivariate analysis identified previous or synchronous adenomas (odds ratio, 1.98; 95 percent confidence interval, 1.16–3.38) as independent predictive factor. Neither presence of tumor DNA microsatellite instability nor family history correlated with the presence of metachronous neoplasms. Conclusions Patients with previous or synchronous colorectal adenoma have an increased risk of developing metachronous colorectal neoplasms. Accordingly, this subgroup of patients may benefit from specific surveillance strategies. Supported by grants from the Red Nacional de Investigación en Hepatología y Gastroenterología (Instituto de Salud Carlos III, C03/02) and from Fondo de Investigaciones Sanitarias (FIS PI061384). Xavier Llor is a recipient of a Ramon y Cajal grant form Ministerio de Ciencia y Tecnología of the Spanish government Presented at the meeting of the United European Gastroenterology, Copenhagen, Denmark, October 15 to 19, 2005.     

Fibrin glue for refractory hemorrhagic cystitis after unrelated marrow, cord blood, and haploidentical hematopoietic stem cell transplantation

BACKGROUND: Patients undergoing hematopoietic stem cell transplant (HSCT) are particularly exposed to the risk of developing hemorrhagic cystitis (HC), which is characterized by symptoms ranging from macroscopic hematuria to renal failure. Although HC significantly affects the quality of life and in a few cases becomes intractable leading to patient death, its therapeutic management has not been established. Fibrin glue (FG), a hemostatic agent derived from human plasma, has been largely employed in different surgical settings including urologic procedures.
STUDY DESIGN AND METHODS: In this pilot study we used FG to treat refractory HC. During cystoscopy, bladder distension was maintained at a constant pressure of 12 mmHg by a carbon dioxide insufflator. An endoscopic applicator allowed spraying FG on the bleeding and raw surfaces of bladder mucosa.
RESULTS: Five of 221 patients undergoing an HSCT developed a very severe, refractory HC and have been treated with endoscopic FG. The treatment was successful in 3 patients; the response was partial in 1 patient and transient in the last one, whose clinical course was severely complicated by acute graft-versus-host disease and multiple organ failure.
CONCLUSIONS: FG therapy is a feasible procedure and this pilot study suggests that it may be an effective treatment for refractory HC. Its application could be considered also in Grade 1 or 2 HC to prevent progression of damaged mucosa. The use of FG for HC should be prospectively investigated in terms of therapeutic efficacy, transfusion support, length of hospitalization, quality of life, and costs.     

Physical disability and muscular strength in relation to obesity and different body composition indexes in a sample of healthy elderly women

OBJECTIVES: The aim of the present study was to test the association between muscular strength, functional limitations, body composition measurements and indexes of sarcopenia in a sample of community-dwelling, elderly women at the high end of the functional spectrum. DESIGN: Cross-sectional. SUBJECTS: In all, 167 women aged 67-78 y were selected from the general population in central Verona. A group of 120 premenopausal healthy women aged 20-50 y represented the young reference group. MEASUREMENTS: Body weight, height, body mass index (BMI) and the presence of acute and chronic conditions were evaluated in each subject. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Physical functioning was assessed using a modified version of the Activities of Daily Living Scale. Dominant leg isometric strength was measured with a Spark Handheld Dynamometer. RESULTS: Elderly women with BMI higher than 30 kg/m(2) and in the highest quintile of body fat percent showed a significantly higher prevalence of functional limitation. In our population study, about 40% of sarcopenic elderly women and 50% of elderly women with high body fat and normal muscle mass were functionally limited. The prevalence of functional limitation significantly increased in subjects with class II sarcopenia, defined according to the skeletal muscle mass index (SMI=skeletal muscle mass/body mass x 100). In logistic regression models, after adjusting for age and different chronic health conditions, subjects with BMI higher than 30 kg/m(2), in the highest quintile of body fat, or with high body fat and normal muscle mass or class II sarcopenia according to SMI, had a 3-4 times increased risk of functional limitations. Finally, isometric leg strength was significantly lower in subjects in the lowest quintile of relative muscle mass and in sarcopenic and sarcopenic obese women. CONCLUSIONS: High body fat and high BMI values were associated with a greater probability of functional limitation in a population of elderly women at the high end of the functional spectrum. Among the different indexes of sarcopenia used in this study, only SMI predicted functional impairment and disability. Isometric leg strength was significantly lower in subjects with sarcopenia and sarcopenic obesity.     

Haematogenous vertebral osteomyelitis. Experience of a primary care hospital

ObjectivesTo describe a series of patients with haematogenous vertebral osteomyelitis (HVO) in a primary care hospital. The results were compared with other Spanish and foreign series.Patients and methodsThe files of patients with HVO diagnosed in the Viladecans hospital from 1993 through 2008, were retrospectively reviewed. Only patients with microbiological demonstration of infection were included. Patients with HVO after surgical procedures were excluded.ResultsTwenty six patients had inclusion criteria, 9 females and 17 males, with a mean age of 61 years (range 36–83). The most patients had any predisposing factor, generally diabetes mellitus. Pyogenic microorganisms were the most frequent aetiological agents (77%). Back pain was by far the most common presenting symptom (88,4%), followed by peripheral septic arthritis in two patients (7,6%), and acute abdominal pain in one. Fever was found in 22 cases (84,6%). None of our patients died, but the sequelae were non rare.ConclusionWe did not find difference between our series and others. It is noteworthy that the streptococcal species represents the most frequently isolated organism, followed by Staphylococcus aureus, more common in other series. Remarkably, none of our patients died. HVO is a infrequent disease. However, evidence suggest that the incidence is increasing. Early diagnosis can avoid potential serious sequelae.     

Postpolycythaemic myelofibrosis: frequency and risk factors for this complication in 116 patients

Postpolycythaemic myelofibrosis (PPMF) is a known complication of polycythaemia vera (PV) but information regarding its incidence and predisposing factors is not well defined. In 116 subjects consecutively diagnosed with PV in a single institution (median age 62 years, range: 20–88), the probability of PPMF was analysed by the Kaplan–Meier method, followed by the log-rank test. With a mean follow-up of 8 years (95% confidence interval: 6·6–9), 17 patients had evolved into PPMF (15%). The probability of evolution to PPMF was 16% at 10 years and 34% at 15 years. Age, gender, spleen size, leucocytosis, thrombocytosis or cytoreductive treatment were not associated with an increased risk of PPMF. The actuarial probability of PPMF at 15 years was higher in those patients presenting at diagnosis with endogenous megakaryocytic colony formation (59% when present versus 10% when absent, P  = 0·03), an elevated serum lactate dehydrogenase (LDH) level (69% vs. 23% in patients with normal LDH, P  = 0·04), and in those who were heterozygous for the JAK2 V617F mutation (55% vs. 17% in heterozygotes, P  = 0·04). In conclusion, PPMF is a frequent complication in PV patients at 15 years with the risk being higher in patients with increased LDH, endogenous megakaryocytic colony formation or a high JAK2 V617F allele burden.     

Osmolyte-induced separation of the mechanical folding phases of ubiquitin

Solvent molecules play key roles in the conformational dynamics of proteins. Here we use single molecule force-clamp spectroscopy to probe the role played by the stabilizing osmolyte glycerol on the conformational ensembles visited by a single ubiquitin protein folding after mechanical extension. Using a variety of force-pulse protocols, we find that glycerol stabilizes the native state of ubiquitin, making it more resistant to mechanical unfolding. We also find that although glycerol enhanced the hydrophobic collapse of unfolded and highly extended ubiquitins, it had no effect on the resulting collapsed states that are essential precursors of the folded state. These disparate effects of glycerol may be the result of distinct structural roles played by solvent molecules at the transition state of each folding ensemble. Our results open the way for a detailed analysis of the transition state structures that form along the folding trajectory of a mechanically extended protein.     

Epidemiology of known diabetes in Lombardy,north Italy

Diabetes epidemiology can benefit in Italy from the large network of outpatient diabetic clinics and patients' facilities. A large investigation was carried out in 1988, in a certain area of northern Italy, to estimate the prevalence of known diabetes. Using four information sources, 4547 distinct patients were identified. Through the capture-recapture method we assessed completeness and estimated a prevalence of 3.3%. Prevalence of type 1 diabetes was 0.8 per 1000. Italian age-standardised overall prevalence and developed-world standardised rates were 2.8% and 2.6%, respectively. A representative sample of 2358 patients was characterised through a standard questionnaire. Women were diagnosed about 6 years later than men (58.8±0.4 vs 52.9±0.4,P<0.0001), while the duration of the disease was very similar in both sexes (9.9±0.2 vs 9.5±0.2). As regards diabetes therapy, 17.2% of the patients were on diet alone, 62.1% on oral agents and 20.6% on insulin. Among the insulin-treated subjects more than half were on adjuvant therapy with tablets, and only 6.2% were treated with 3 injections/day. Less than half of all the known diabetic subjects had had an ophthalmoscopic examination in the previous 2 years.