Rapid Growth of Nanostructured Diamond Film on Silicon and Ti–6Al–4V Alloy Substrates

Nanostructured diamond (NSD) films were grown on silicon and Ti–6Al–4V alloy substrates by microwave plasma chemical vapor deposition (MPCVD). NSD Growth rates of 5 μm/h on silicon, and 4 μm/h on Ti–6Al–4V were achieved. In a chemistry of H₂/CH₄/N₂, varying ratios of CH₄/H₂ and N₂/CH₄ were employed in this research and their effect on the resulting diamond films were studied by X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. As a result of modifying the stock cooling stage of CVD system, we were able to utilize plasma with high power densities in our NSD growth experiments, enabling us to achieve high growth rates. Substrate temperature and N₂/CH₄ ratio have been found to be key factors in determining the diamond film quality. NSD films grown as part of this study were shown to contain 85% to 90% sp³ bonded carbon.     

A salivary sensor for the management of xerostomia in edentulous patients

This article describes a method for managing xerostomia in edentulous patients with a newly developed salivary sensor. A micropressure sensor unit with a capsule to hold artificial salivary substitute was built into the dental prosthesis. This sensor prosthesis can help patients overcome mouth dryness, improves patient comfort, and aids in retention of the prosthesis.     

White paper on antimicrobial stewardship in solid organ transplant recipients

Antimicrobial stewardship programs (ASPs) have made immense strides in optimizing antibiotic, antifungal, and antiviral use in clinical settings. However, although ASPs are required institutionally by regulatory agencies in the United States and Canada, they are not mandated for transplant centers or programs specifically. Despite the fact that solid organ transplant recipients in particular are at increased risk of infections from multidrug-resistant organisms, due to host and donor factors and immunosuppressive therapy, there currently are little rigorous data regarding stewardship practices in solid organ transplant populations, and thus, no transplant-specific requirements currently exist. Further complicating matters, transplant patients have a wide range of variability regarding their susceptibility to infection, as factors such as surgery of transplant, intensity of immunosuppression, and presence of drains or catheters in situ may modify the risk of infection. As such, it is not feasible to have a “one-size-fits-all” style of stewardship for this patient population. The objective of this white paper is to identify opportunities, risk factors, and ASP strategies that should be assessed with solid organ transplant recipients to optimize antimicrobial use, while producing an overall improvement in patient outcomes. We hope it may serve as a springboard for development of future guidance and identification of research opportunities.     

Development of a Method That Eliminates False-Positive Results due to Nerve Growth Factor Interference in the Assessment of Fulranumab Immunogenicity

Fulranumab, a human IgG2 monoclonal antibody that neutralizes nerve growth factor (NGF), is currently in development for the treatment of pain. Our initial immunogenicity test method was found to be prone to NGF interference, leading to a high apparent incidence of anti-drug antibody (ADA) in phase 1 studies. The ADA immunoassay comprised a homogeneous bridging electrochemiluminescence (ECL) format with biotin and ruthenium-labeled fulranumab bound together (“bridged”) by ADA in test samples for detection. In this assay, NGF produced a false-positive signal due to its ability to bridge fulranumab molecules. Thus, we developed a specificity assay to eliminate the NGF false-positive results. We encountered the challenge of eliminating drug interference as well as drug target interference, and discovered that the acid-dissociation-based pretreatment of samples used for mitigating drug interference dramatically increased drug target interference. Several strategies were investigated to eliminate the NGF interference; yet only one strategy specifically removed NGF and produced true fulranumab-specific ADA results by using competitive inhibition with fulranumab and utilizing an alternative NGF binding antibody to eliminate NGF interference. Using this new method, we confirmed that the high apparent anti-fulranumab antibody incidence (>60%) in clinical study samples was in fact due to fulranumab-bound NGF released during the acid-dissociation step of the ADA testing method. We conclude that our revised method accurately identifies anti-fulranumab antibodies by incorporating steps to eliminate fulranumab and NGF interference. We advise that acid-dissociation pretreatment must not be universally applied to improve ADA assays without investigating its bioanalytical risks versus benefits.     

Annual risk of tuberculous infection in four defined zones of India: a comparative picture.

SETTING: Twenty-six selected districts in India. OBJECTIVES: To estimate the average annual risk of tuberculous infection (ARTI) in four defined zones in the country. STUDY DESIGN: A tuberculin survey was conducted in selected clusters of 26 districts in four defined zones of India. Children 1-9 years of age were subjected to tuberculin testing with ITU PPD RT23 with Tween 80, and the maximum transverse diameter of induration was measured 72 h later. Prevalence of infection was estimated using the cut-off point method (Method I) and the mirror-image technique (Method II) among children without bacille Calmette-Guérin scar. Results from individual zones have been reported earlier, and the results from all four zones are presented here as a consolidated summary. RESULTS: The ARTI computed from estimated prevalence was found to be lowest in the southern zone (Method I: 1.1%, Method II: 1.0%). It was higher in the eastern zone (1.3% by both methods) and highest in the western (Method I: 1.8%, Method II: 1.6%) and northern zones (1.9% by both methods). The proportion of infected children was found to be significantly higher in urban than in rural areas in all zones. CONCLUSION: The intensified tuberculosis control efforts need to be sustained for many years.     

Reference values of ECG parameters derived from 906 echocardiographically confirmed healthy Indian children: A population-based study from Gujarat

Introduction

There are few published studies on reference ranges of ECG parameters in children; some ethnic differences have been described.

Atrial synchronous left ventricular only pacing with VDD pacemaker system – A cost effective alternative to conventional cardiac resynchronization therapy

Introduction

Atrial synchronous left ventricular (LV) only pacing using two leads and VDD pacemaker could be a cost effective alternative to conventional cardiac resynchronization therapy (CRT).

Methods

We implanted right atrial (RA) and LV leads with VDD pulse generator (LV only pacing) in five carefully screened heart failure patients who could not afford conventional CRT. All had NYHA class III/IV symptoms despite maximal guideline directed medical therapy. The sensed atrioventricular delay was programmed to pre-excite the LV and achieve fusion beat. Response to treatment was assessed at 6 months.

Results

Four patients were males. The mean age was 58 ± 12 years. At follow up, there was improvement in electrocardiographic, and echocardiographic parameters: Mean QRS duration decreased from 174 ± 17 msec to 128 ± 10.9 msec (p = 0.009), LV end-diastolic diameter decreased from 73.2 ± 12 mm to 65.8 ± 9.6 mm (p = 0.026), LV end-systolic diameter decreased from 65 ± 12 mm to 54 ± 10 mm (p = 0.020). There was a trend towards reduction of LV end-systolic and end-diastolic volumes. LV ejection fraction improved from 25 ± 6% to 34 ± 6% (p = 0.013) and left atrial dimension reduced from 44 ± 4 mm to 39 ± 5 mm (p = 0.045). All patients improved clinically.

Conclusion

RA-LV pacing using VDD pacemaker is a safe and effective technique of CRT. This may be a cost effective alternative to conventional CRT for patients in developing countries.     

Bedside upper gastrointestinal series in critically ill low birth weight infants

Background

The upper gastrointestinal (UGI) series is the preferred method for the diagnosis of malrotation. A bedside UGI technique was developed at our institution for use in low birth weight, critically ill neonates to minimize the risks of transportation from the neonatal intensive care unit (NICU) such as hypothermia and dislodgement of support lines and tubes.

Objective

To determine the ability of a bedside UGI technique to identify the position of the duodenojejunal junction (DJJ) in low birth weight, critically ill infants in the NICU.

Materials and methods

We retrospectively reviewed bedside UGI examinations performed in premature infants weighing less than 1,500 g from 2008 to 2013 and correlated the findings with clinical data, imaging studies and surgical findings.

Results

Of 27 patients identified (weight range: 633–1,495 g), 21 (78%) bedside UGI series were diagnostic. Twenty of 27 cases (74%) demonstrated normal intestinal rotation. One case demonstrated malrotation with midgut volvulus, which was confirmed at surgery. In six cases (22%), the position of the DJJ could not be accurately determined. No cases of malrotation with midgut volvulus were missed. None of the patients with normal bedside UGI studies was found to have malrotation based on clinical follow-up (mean: 20 months), surgical findings or further imaging.

Conclusion

The bedside UGI is a useful technique to exclude malrotation in critically ill neonates and minimizes potential risks of transportation to the radiology suite. Pitfalls that may preclude a diagnostic examination include incorrect timing of radiographs, patient rotation, suboptimal enteric tube position and bowel distention. In cases of diagnostic uncertainty, a follow-up study should be performed.