Can We Restart the First-Line Antibiotic as Empirical Choice When Enteric Fever is Suspected?

Enteric fever is a major health problem in Bangladesh. Antibiotic resistance especially against first-line antibiotics is a major concern in the management and thereby not practicing by physician as first choice thinking their resistance. This retrospective study was carried out in the Department of Microbiology, Bangladesh Medical College Hospital, Dhaka, Bangladesh from January of 2017 to December of 2019 to identify the year wise sensitivity pattern of first-line antibiotics like Amoxycillin, Cotrimoxazole and Chloramphenocol against Salmonella typhi and Salmonella paratyphi. All the blood samples sent for culture and sensitivity were evaluated to see the microbiom and their sensitivity pattern. Salmonella typhi and paratyphi were the major isolates in last 3 years which were 73.74% and 15.32% respectably. Sensitivity pattern of Amoxycillin, Cotrimoxazole and Chloramphenocol for Salmonella typhi is increased from 2017 to 2019 which were 66.0 to 83.0%, 80.0 to 83.0% and 84.0 to 85.0% respectively. Similar increasing pattern of sensitivity found in Salmonella paratyphi which was 82.5 to 89.2%, 76.2 to 95.4%, 98.7 to 98.5% respectively. They were also found highly sensitive (>90.0%) to 3rd generation cephalosporin. This study recommends the use of first-line antibiotics as empirical agent of choice in enteric fever as they are still highly sensitive against Salmonella typhi and Salmonella paratyphi.

Atomic packing and short-to-medium-range order in metallic glasses.

Unlike the well-defined long-range order that characterizes crystalline metals, the atomic arrangements in amorphous alloys remain mysterious at present. Despite intense research activity on metallic glasses and relentless pursuit of their structural description, the details of how the atoms are packed in amorphous metals are generally far less understood than for the case of network-forming glasses. Here we use a combination of state-of-the-art experimental and computational techniques to resolve the atomic-level structure of amorphous alloys. By analysing a range of model binary systems that involve different chemistry and atomic size ratios, we elucidate the different types of short-range order as well as the nature of the medium-range order. Our findings provide a reality check for the atomic structural models proposed over the years, and have implications for understanding the nature, forming ability and properties of metallic glasses.

Prognostic value of systolic mitral annular velocity measured with Doppler tissue imaging in patients with chronic heart failure caused by left ventricular systolic dysfunction.

OBJECTIVE: To assess the prognostic value of various conventional and novel echocardiographic indices in patients with chronic heart failure (CHF) caused by left ventricular (LV) systolic dysfunction. METHODS: 185 patients with a mean (SD) age of 67 (11) years with CHF and LV ejection fraction < 45% despite optimal pharmacological treatment were prospectively enrolled. The patients underwent two dimensional echocardiography with tissue harmonic imaging to assess global LV systolic function and obtain volumetric data. Transmitral flow was assessed with conventional pulse wave Doppler. Systolic (Sm), early, and late diastolic mitral annular velocities were measured with the use of colour coded Doppler tissue imaging. RESULTS: During a median follow up of 32 months (range 24-38 months in survivors), 34 patients died and one underwent heart transplantation. Sm velocity (hazard ratio (HR) 0.648, 95% confidence interval (CI) 0.463 to 0.907, p = 0.011), diastolic arterial pressure (HR 0.965, 95% CI 0.938 to 0.993, p = 0.015), serum creatinine (HR 1.006, 95% CI 1.001 to 1.011, p = 0.023), LV ejection fraction (HR 0.945, 95% CI 0.899 to 0.992, p = 0.024), age (HR 1.035, 95% CI 1.000 to 1.071, p = 0.052), LV end systolic volume index (HR 1.009, 95% CI 0.999 to 1.019, p = 0.067), and restrictive pattern of transmitral flow (HR 0.543, 95% CI 0.278 to 1.061, p = 0.074) predicted the outcome of death or transplantation on univariate analysis. On multivariate analysis, only Sm velocity (HR 0.648, 95% CI 0.460 to 0.912, p = 0.013) and diastolic arterial pressure (HR 0.966, 95% CI 0.938 to 0.994, p = 0.016) emerged as independent predictors of outcome. CONCLUSIONS: In patients with CHF and LV systolic dysfunction despite optimal pharmacological treatment, the strongest independent echocardiographic predictor of prognosis was Sm velocity measured with quantitative colour coded Doppler tissue imaging.

Icosahedral short-range order in amorphous alloys.

We have characterized the icosahedral short-range order in amorphous solids using local environment probes. Such topological local order is pronounced even in an amorphous alloy that does not form quasicrystalline phases upon crystallization, as demonstrated by the extended x-ray absorption fine structure and x-ray absorption near-edge structure of a Ni-Ag amorphous alloy analyzed through reverse Monte Carlo simulations.

What is the optimal medical management of ischemic heart failure?

Ischemic heart disease is an important and common contributor to the development of heart failure. Theoretically, all patients with heart failure may benefit from treatment designed to retard progressive ventricular dysfunction and arrhythmias. Patients with ischemic heart disease may also theoretically benefit from the relief of ischemia, the prevention of coronary occlusion, and revascularization. However, there is little evidence to show that the presence or absence of coronary disease modifies the benefits of effective treatments such as angiotensin-converting enzyme inhibitors and beta-blockers. Moreover, there is no evidence that treatment directed specifically at myocardial ischemia or coronary disease alters outcome in patients with heart failure. Treatments aimed at relieving painless myocardial ischemia have not been shown to alter prognosis. Lipid-lowering therapy is theoretically attractive for patients with heart failure and coronary disease; however, theoretical concerns also exist about the safety of such agents, and patients with heart failure have been excluded from large outcome studies very effectively. Some agents, such as aspirin, designed to reduce the risk of coronary occlusion seem ineffective or harmful in patients with heart failure, although warfarin may be safe and possibly effective. There is no evidence yet that revascularization improves prognosis in patients with heart failure, even in patients who are shown to have extensive myocardial hibernation. On current evidence, revascularization should be reserved for the relief of angina. Large-scale, randomized controlled trials are currently underway that are investigating the role of specific treatments targeted at coronary syndromes. The Carvedilol Hibernation Reversible Ischemia Trial: Marker of Success study is investigating the effects of carvedilol in a large cohort of patients with and without hibernating myocardium. The Warfarin and Antiplatelet Therapy in Chronic Heart Failure study is comparing the efficacy of aspirin, clopidogrel, and warfarin. The Heart Revascularization Trial-United Kingdom study is assessing the effect of revascularization on mortality in patients with heart failure and myocardial hibernation. Smaller scale studies are assessing the safety and efficacy of statin therapy in patients with heart failure. Only once the outcomes to these and other planned trials are known can the medical community know how best to treat their patients.

The role of signal averaged P wave duration and serum magnesium as a combined predictor of atrial fibrillation after elective coronary artery bypass surgery.

OBJECTIVE: To investigate the role of low serum magnesium as a trigger for atrial fibrillation in patients with a substrate for the arrhythmia (assessed by signal averaged P wave duration). DESIGN: A case-control study. SETTING: A regional referral cardiac centre. PATIENTS AND INTERVENTIONS: 105 consecutive patients undergoing elective coronary artery bypass surgery had signal averaged P wave recordings before operation. Serum electrolytes were analysed preoperatively and on days 1, 2, and 5 after surgery. MAIN OUTCOME MEASURES: Any episode of electrocardiographically recorded atrial fibrillation was taken as a study end point. RESULTS: Of 102 patients discharged, 27 (26%) had documented episodes of atrial fibrillation at a mean of 2.7 days after surgery. A combination of P wave duration > 155 ms and serum magnesium on the first postoperative day of < 0.7 mmol/l had a sensitivity of 75% and specificity of 80% for predicting atrial fibrillation. Duration of hospital stay (7.9 v 6.8 days) was longer in the atrial fibrillation group (P < 0.01). Stepwise regression showed age, serum magnesium < 0.7 mmol/l on the first postoperative day (both P < 0.001), angiotensin converting enzyme inhibitor withdrawal (P < 0.02), and signal averaged P wave duration (P = 0.04) to be independent predictors. CONCLUSIONS: The combination of signal averaged P wave duration and low serum magnesium on the first postoperative day identified the majority of patients with atrial fibrillation after coronary artery bypass surgery. Early identification and pharmacological treatment for selected patients may reduce the incidence of postoperative atrial fibrillation.