157 research outputs found
Kinetic and mechanistic studies of oxidation of an antiallergic drug with bromamine-t in acid and alkaline media
Cetrizine dihydrochloride (CTZH) is widely used as an anti-allergic drug. Sodium N-bromo-p-toluenesulfonamide or bromamine-T (BAT) is the bromine analogue of chloramine-T (CAT) and is found to be a better oxidizing agent than CAT. In the present research, the kinetics of oxidation of CTZH with BAT in acid and alkaline media was studied at 313 K. The experimental rate laws obtained are: -dBAT/dt = kBAT CTZH0.80H+-0.48 in acid medium and -dBAT/dt = kBATCTZH0.48OH-0.52PTS-0.40 in alkaline medium where PTS is p-toluenesulfonamide. Activation parameters and reaction constants were evaluated. The solvent isotope effect was studied using D2O. The dielectric effect is positive. The stoichiometry of the reaction was found to be 1:1 and the oxidation products were identified as 4-chlorobenzophenone and (2- piperazin-1-yl-ethoxy)-acetic acid in both media. The rate of oxidation of CTZH is faster in acid medium. Suitable mechanisms and related rate laws have been worked out
Oxidation of tricyclic antidepressant drugs with chloramine-T in acidic solutions: Kinetic, mechanistic and thermodynamic studies
The kinetics of the oxidation of two tricyclic antidepressants (TCA) namely, imipramine (IMP) and clomipramine (CLM) with sodium N-chloro-p-toluenesulfonamide or chloramine-T (CAT) in HClO4 medium was studied at 300 K. The two reactions followed identical kinetics with a first-order dependence of rate on CATo and fractional order dependence on TCAo. The reaction is catalyzed by H+ ions with a fractional order dependence. The reaction was studied at different temperatures and activation parameters were evaluated. The reaction constants involved in the mechanism were computed. The solvent isotope effect was studied using D2O. Addition of p-toluenesulfonamide retards the reaction rate. The rate increased with decreasing dielectric constant of the medium. Variation of ionic strength of the medium and addition of halide ions (Cl- or Br-) showed no effect on the rate. The stoichiometry of the reaction was found to be 1:1 and the oxidation products were identified as imipramine-5-N-oxide and clomipramine-5-N-oxide. The rate of oxidation of IMP is faster than CLM. The observed results have been explained in terms of a mechanism and a relevant rate law has been deduced. © 2013 Sukhdev and Puttaswamy; licensee Springer
Patients with Endoscopically Visible Polypoid Adenomatous Lesions Within the Extent of Ulcerative Colitis Have an Increased Risk of Colorectal Cancer Despite Endoscopic Resection.
OBJECTIVES: Ulcerative colitis (UC) is associated with an increased risk of colorectal cancer (CRC). Few studies have looked at long-term outcomes of endoscopically visible adenomatous lesions removed by endoscopic resection in these patients. We aimed to assess the risk of developing CRC in UC patients with adenomatous lesions that develop within the segment of colitis compared to the remainder of an ulcerative colitis cohort. METHODS: We identified patients with a confirmed histological diagnosis of UC from 1991 to 2004 and noted outcomes till June 2011. The Kaplan-Meier method was used to estimate cumulative probability of subsequent CRC. Factors associated with risk of CRC were assessed in a Cox proportional hazards model. RESULTS: Twenty-nine of 301 patients with UC had adenomatous lesions noted within the segment of colitis. The crude incidence rate of developing colon cancer in patients with UC was 2.45 (95 % CI 1.06-4.83) per 1000 PYD and in those with UC and polypoid adenomas within the extent of inflammation was 11.07 (95 % CI 3.59-25.83) per 1000 PYD. Adjusted hazards ratio of developing CRC on follow-up in UC patients with polypoid dysplastic adenomatous lesions within the extent of inflammation was 4.0 (95 % CI 1.3-12.4). CONCLUSIONS: The risk of developing CRC is significantly higher in UC patients with polypoid adenomatous lesions, within the extent of inflammation, despite endoscopic resection. Patients and physicians should take the increased risk into consideration during follow-up of these patients
Postoperative pain as a risk factor for stiff knee following total knee arthroplasty and excellent patient-reported outcomes after manipulation under anesthesia
Background and purpose - Manipulation under anesthesia (MUA) is the first-choice treatment for stiffness following total knee arthroplasty (TKA) unresponsive to pain management and physiotherapy. Some of the predisposing factors and patient-reported outcome measures (PROMs) following MUA remain poorly studied. We retrospectively investigated the etiological risk factors and the outcomes of MUA. Patients and methods - 391 TKA patients from a randomized trial comparing the use of a tourniquet and anesthesia (spinal or general) were analyzed, and patients needing MUA were identified (MUA group). We evaluated in-hospital opioid consumption, Oxford Knee Score (OKS), range of motion (ROM), and pain assessed by the Brief Pain Inventory-short form with a 1-year follow-up. Results - 39 (10%) MUA patients were identified. The MUA patients were younger (60 years vs. 64 years, difference -4, 95% CI -6 to -1) and had higher postoperative oxycodone consumption (66 mg vs. 51 mg, median difference 11, CI 1-22) than the no-MUA patients. The proportion of MUA patients who contacted the emergency department within 3 months because of pain was larger than that of non-MUA patients (41% vs. 12%, OR 5, CI 3-10). At the 1-year follow-up, the ROM was improved by 39 degrees following MUA, but the total ROM was worse in the MUA group (115 degrees vs. 124 degrees, p < 0.001). No difference was found in the OKS between the MUA and no-MUA patients. Interpretation - Higher postoperative pain seems to predict MUA risk. MUA performed 3 months postoperatively offers substantial ROM improvement and comparable PROMs to no-MUA patients 1 year after TKA.Peer reviewe
An agenda for integrated system-wide interdisciplinary agri-food research
© 2017 The Author(s)This paper outlines the development of an integrated interdisciplinary approach to agri-food research, designed to address the ‘grand challenge’ of global food security. Rather than meeting this challenge by working in separate domains or via single-disciplinary perspectives, we chart the development of a system-wide approach to the food supply chain. In this approach, social and environmental questions are simultaneously addressed. Firstly, we provide a holistic model of the agri-food system, which depicts the processes involved, the principal inputs and outputs, the actors and the external influences, emphasising the system’s interactions, feedbacks and complexities. Secondly, we show how this model necessitates a research programme that includes the study of land-use, crop production and protection, food processing, storage and distribution, retailing and consumption, nutrition and public health. Acknowledging the methodological and epistemological challenges involved in developing this approach, we propose two specific ways forward. Firstly, we propose a method for analysing and modelling agri-food systems in their totality, which enables the complexity to be reduced to essential components of the whole system to allow tractable quantitative analysis using LCA and related methods. This initial analysis allows for more detailed quantification of total system resource efficiency, environmental impact and waste. Secondly, we propose a method to analyse the ethical, legal and political tensions that characterise such systems via the use of deliberative fora. We conclude by proposing an agenda for agri-food research which combines these two approaches into a rational programme for identifying, testing and implementing the new agri-technologies and agri-food policies, advocating the critical application of nexus thinking to meet the global food security challenge
Effect of Obesity on Acute Ozone-Induced Changes in Airway Function, Reactivity, and Inflammation in Adult Females
We previously observed greater ozone-induced lung function decrements in obese than non-obese women. Animal models suggest that obesity enhances ozone-induced airway reactivity and inflammation. In a controlled exposure study, we compared the acute effect of randomized 0.4ppm ozone and air exposures (2 h with intermittent light exercise) in obese (N = 20) (30<BMI<40Kg/m2) vs. non-obese (N = 20) (BMI<25Kg/m2) non-smoking 18–35 year old women. We measured spirometry and bronchial reactivity to inhaled methacholine (3h post-exposure). Inflammation and obesity markers were assessed in the blood (pre, 4h post, and 20h post exposures) and induced-sputum (4h post-exposures and on 24h pre-exposure training day, no exercise): measures of C reactive protein (CRP) (blood only), leptin (blood only), adiponectin, interleukins IL-6, IL-1b, and IL-8, and tumor necrosis factor alpha, and sputum cell differential cell counts. The pre- to post-exposure decrease in forced vital capacity after ozone (adjusted for the change after air exposure) was significantly greater in the obese group (12.5+/-7.5 vs. 8.0+/-5.8%, p<0.05). Post ozone exposure, 6 obese and 6 non-obese subjects responded to methacholine at ≤ 10mg/ml (the maximum dose); the degree of hyperresponsiveness was similar for the two groups. Both BMI groups showed similar and significant ozone-induced increases in sputum neutrophils. Plasma IL-6 was increased by exercise (4 hr post air exposure vs. pre) only in the obese but returned to pre-air exposure levels at 20hr post-exposure. Plasma IL-6 was significantly increased at 4hr post ozone exposure in both groups and returned to pre-exposure levels by 20h post-exposure. These results confirm our previous findings of greater post-ozone spirometric decrements in obese young women. However, acute ozone-induced airway reactivity to methacholine and airway inflammation did not differ by obesity at the exposure and exercise levels used
The negative compatibility effect: A case for self-inhibition
In masked priming, a briefly presented prime stimulus is followed by a mask,
which in turn is followed by the task-relevant target. Under certain conditions,
negative compatibility effects (NCNCEs) occur, with impaired performance on
compatible trials (where prime and target indicate the same response) relative
to incompatible trials (where they indicate opposite responses). However, the
exact boundary conditions of NCEs, and hence the functional significance of this
effect, are still under discussion. In particular, it has been argued that the
NCE might be a stimulus-specific phenomenon of little general interest. This
paper presents new findings indicating that the NCE can be obtained under a
wider variety of conditions, suggesting that it reflects more general processes
in motor control. In addition, evidence is provided suggesting that prime
identification levels in forced choice tasks – usually employed to estimate
prime visibility in masked prime tasks – are affected by prior experience with
the prime (Exp. 1) as well as by direct motor priming (Exp. 2 & 3)
Automated detection of sleep disordered breathing using a nasal pressure monitoring device
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