Toxicological Profiling of Potential Shikimate Kinase Inhibitors Against Mycobacterium tuberculosis

Over the last decade, Mycobacterium tuberculosis has mutated into a putative 'superbug', as treatments against it have failed due to increasing antimicrobial resistance. As a result, the rising incidence of multidrug-resistant tuberculosis (MDR-TB) is posing a significant public health threat, thus, the need to develop effective drugs for MDR-TB has become an urgent priority. To identify new drug candidates for the treatment of MDR-TB, the present study was based on mycobacterial shikimate kinase (MtSK) as the pharmacological target. One hundred potential MtSK inhibitors were identified from literature and database searches to identify compounds that were designed to specifically function as MtSK antagonists. The ADME properties of these compounds were evaluated by using the SwissADME web tool. ProTox-II software was also used to investigate any potential endocrine disrupting effects, mediated through their interaction with oestrogenic and/or androgenic receptors. This study also aimed to predict LD50 values of potential drug candidates that would be active against the standard H37Rv strain of M. tuberculosis, by using the ProTox-II in silico tool. The molecules for which no structural hazard alerts were identified with these software tools were further subjected to molecular docking analyses and molecular dynamic simulations to estimate their ability to interact with the MtSK enzyme. Preliminary results from SwissADME indicated that 30 molecules were drug-like, due to their physicochemical and pharmacokinetic properties. However, subsequent analysis with ToxTree and ProTox-II indicated that only three of these 30 drug-like molecules were suitable for taking forward into further in vitro experiments. This study, which is based on the use of commonly used open-source in silico tools, identified new MtSK ligands for potential use in the development of new drugs for the therapeutic management of tuberculosis. An initial prediction of their safety profile was also generated.

Physical exam is not an accurate predictor of injury in geriatric patients with low-energy blunt trauma - A retrospective cohort study

Background

When evaluating trauma patients, many centers perform computed tomography of the head, cervical spine, chest, abdomen, and pelvis, the so-called “pan-scan.” Here, we evaluate the utility of physical exam against pan-scan in geriatric patients who sustained ground-level falls.

Methods

We performed a single-centered retrospective cohort review of consecutive patients from the trauma registry of a large, urban Level 1 trauma center. Inclusion criteria were registration during the 2019 calendar year, age ≥65, mechanism of fall from either sitting or standing, and performance of “pan-scan” at time of assessment. The sensitivity, specificity, positive and negative predictive values of the physical exam for significant injuries were calculated. The effect of such injuries on disposition from the emergency department and hospital were determined.

Results

An initial query for patients age ≥65 yielded 1280 patients. After exclusion of patients who did not undergo pan-scan or who had GCS <14, 751 patients were included in analysis. Median age was 84 years old. 351 patients had at least one injury identified on pan-scan. Physical exam was determined to have a sensitivity of 0.69 when compared to pan-scan as a gold standard. Patients with injury identified on CT scan had significantly more admissions, mortalities, and ICU and OR requirements.

Conclusion

Approximately half of all patients were found to have at least one injury on pan-scan. Physical examination was insensitive at identifying such injuries which ultimately altered patient management, disposition, and outcomes. Pan-scan is recommended in this vulnerable population.

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A selective approach to CT scan may not be appropriate for elderly patients with low-energy blunt falls.

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Approximately half of all elderly patients who fall from sitting or standing have at least one traumatic injury.

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Traumatic injuries alter the hospital course and disposition of elderly fall patients.

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Physical exam is neither sensitive nor specific enough to detect these injuries.

A proposed "Radiological Evaluation Score for Bone Tumors" (REST): An objective system for assessment of a radiograph in patients with suspected bone tumor

BACKGROUND

Although radiographs have been widely used in the evaluation of patients with suspected bone tumors, the lack of an objective radiological assessment method leads to a challenge in reaching correct diagnosis. The study aimed to propose a Radiological Evaluation Score for Bone Tumors (REST) which includes eight radiological factors [characteristics, content, cortical breach, distinctiveness, distribution, periosteal reaction, fracture, and soft tissue swelling] to form a single score along with its validation by multidisciplinary observers.

METHODS

We reviewed the radiographs of 100 patients with a primary bone tumor which were selected at random from the database between January 2017 and January 2019 of a tertiary cancer center. Four reviewers (two orthopedic oncologists and two surgical oncologists) independently assessed the radiographs, based on the reporting system of REST. We constituted two groups according to the probable diagnosis of bone tumor (suspected benign tumor and suspected malignant tumor).

RESULTS

The mean score in the suspected benign tumor group was 1.1 (range 0-3, 95% CI 0.8-1.3) and in malignant tumor group was 6.1 (range 2-8, 95% CI 5.8-6.4). A receiver operator characteristic (ROC) curve for REST was with a cutoff of 3.5, with the most diagnostic value area under curve (AUC) of 0.99. The sensitivity was 98% and specificity was 100% with a positive predictive value of 100% and a negative predictive value of 98%. The inter-observer correlation coefficient was 0.985 (p value < 0.05), and Fleiss kappa value for the prediction of the benign or malignant lesion was 0.97 (p value < 0.05). The characteristics and content of tumor, cortical erosion, distinctiveness, distribution, periosteal reaction, and soft tissue mass had a significant correlation with the aggressiveness of bone lesion p value < 0.05.

CONCLUSIONS

The Radiological Evaluation Score for Bone Tumors (REST) is a structured reporting and objective method for the assessment of radiographs in patients with suspected bone tumors. This method is a reliable and helpful tool for clinicians in their outdoor patient department to differentiate a radiograph of a suspected benign tumor from a malignant bone tumor.

A proposed ''A to Z RAM (Radiograph Assessment Method)'' for triage of patients with a suspected bone tumour

INTRODUCTION

We propose a ''A to Z RAM (Radiograph Assessment Method)'' for evaluation of Radiograph of patients with a suspected bone tumour.

METHODS

In the current study, ten radiological features with letters 'A, B, C, D, E, F and Z' were used and which included the age of the patient, involved part of the bone, characteristics, content, distinctiveness, the exterior of the bone, fracture, and zone of transition. Four independent observers (orthopaedic oncologists and surgical oncologists) evaluated a set of 30 radiographs of bone tumour selected at random from our hospital database based on A to Z RAM. We classified the lesions into two groups according to the traffic signal system; Green (suspected benign lesion) and Red (suspected malignant lesion).

RESULTS

There were 18 (60%) benign bone lesions and 12 (40%) malignant lesions in the current study. 91.6% of malignant tumours and 88.8% of the benign tumours were identified correctly by the four observers. The inter-observer variability with Fleiss kappa was 0.884 (95% CI 0.7-1.03 p-value < 0.05), suggestive of agreement not by chance. These radiographs were again reassessed by the four observers after 3 months. The interobserver variability by Fleiss kappa was 1.0 (95% CI 0.8-1.1) suggesting complete agreement amongst the observers. Both orthopaedic oncologists had intra-observer kappa as 1.0 each and both surgical oncologists had 0.795 and 0.930 respectively.

CONCLUSION

The proposed A to Z RAM is an easy to use and reproducible method for reviewing radiographs in the out-patient department along with clinical findings for better management of patients with suspected bone lesions. The A to Z RAM can be a medical triage tool and subdivide bone lesions into two subgroups i.e. suspected benign lesion with a suggestion of further investigations with MRI and biopsy and suspected malignant lesion with a suggestion of MRI or early referral to a tertiary cancer center with expertise in orthopaedic oncology.

IMPLICATIONS FOR PRACTICE

The A to Z RAM (Radiologic Assessment Method) is a reproducible method for reviewing radiographs in the out-patient department and can be an aid for better management of patients. A to Z RAM is useful as a medical triage system, subdividing patients according to the probable diagnosis into a suspected benign lesion and suspected malignant lesion.

AB0694 IS THERE ANY HETEROGENEITY OF SPONDYLOARTHRITIS DISEASE MANIFESTATIONS BETWEEN TWO ETHNIC SUBGROUPS?:A MULTICENTRE INTERNATIONAL COMPARATIVE STUDY BETWEEN INDIA AND UK

Background:

Pathogenesis of Spondyloarthritis (SpA) multifactorial and remains unclear. Various hypothesis have been postulated genetics, HLAB27, IL17, Gut microbiome and Biomechanical stress. Many of these factors can be attributed to ethnic background and environment. HLAB27 accounts for 20–25 % of total heritability and 40% of genetic risk while <10% of HLA-B27 carriers in general population develop SpA1. Higher faecal calprotectin levels in SpA compared to control point towards microscopic gut inflammation2. Thus dietary habits and geographical factors can influence pathogenesis of disease. We looked in clinical manifestations of SpA patients of two very different ethnic background Caucasians and Indians from UK and India to shed more light in understanding the disease

Objectives:

To study any differences in the clinical manifestations of SpA patients of two ethnic groups

To compare outcome measure (BASDAI and ASDAS) between Caucasians and Indians

To study the difference in disease activity between Indian patients and British Asians

Methods:

Multicentre observation study where data of SpA patients attending rheumatology clinics from two major teaching hospitals collected. In India data collected from Sheth VS Hospital and NHL Medical College, Gujarat and in United Kingdom from University Hospitals Leicester, NHS trust. Leicester has a multi-ethnic demography wherein almost 30%3of population is of south Asian ethnicity, making this study unique.

Baseline demographic and clinical data was collected. Clinical and outcome measures compared to see any heterogeneity in disease manifestations. SPSS software used

Results:

Total 200 patients analysed with 148 Indians and 52 Caucasians. The Indian cohort was subdivided into British Asians (second generation Indians) and those form Gujarat, India

We found Indian subgroups were younger with shorter disease duration. Comparison in Table 1

Table 1.CaucasianIndianPAge45.9±1231±12<0.001M:F34:193:10.74TDI years9.6 ±5.93.5± 5.2<0.001BASDAI4.05±2.173.1±1.70.002ASDAS2±0.82.4±1.20.02CRP12.8±23.624±12<0.001HLAB2767%26%<0.001Uveitis25%12%0.02IBP78%90%0.03Enthesitis21%60%<0.001Peripheral Arthritis19%36%0.02Dactylitis2%10%0.07Psoriasis10%20%0.1IBD2%5%0.35Comparing British Asians to Indians, Gujarat no significant difference in clinical parameters. (Table 2)British AsianIndianPBASDAI5.16±2.763.1±1.70.006ASDAS2.53±1.32.4±1.20.74CRP15.2 ±15.424±12<0.001

Conclusion:

We found Caucasians had more HLAB27 positivity and extra-articular manifestation of uveitis however the Indian population has more enthesitis and peripheral arthritis. Enthesitis is initiated during a mechano-sensation and the cultural difference including style of footwear could probably be one of the factors explaining our findings inflammatory back pain has been reported to be higher in Indians compared to Caucasians which could be due to life style

The fact that ASDAS CRP behaves similarly in Indian patients across the two countries and is more when compared to Caucasians might point towards overall higher burden of disease in Indian population

To our knowledge this is a first study comparing clinical manifestations of SpA between Indians and Caucasians

References:

[1]Brown MAet al. Susceptibility to ankylosing spondylitis in twins: the role of genes, HLAand environment.Arthritis Rheum 1997;40: 1823–8

[2]J Simione, et al. Fecal Calprotectin, GutInflammation and SpA Archives of Medical Research. 2019;50:41-46

[3]http://www.ons.gov.uk/census

Disclosure of Interests:

Nibha Jain: None declared, Sapan Pandya: None declared, Puja Srivastava: None declared, Prashant Chotalia: None declared, Arumugam Moorthy Speakers bureau: Abbvie, Novartis,UCB,MSD

Quantitative Susceptibility Mapping of Time-Dependent Susceptibility Changes in Multiple Sclerosis Lesions

BACKGROUND AND PURPOSE

MR imaging studies have demonstrated that magnetic susceptibility in multiple sclerosis lesions is dependent on lesion age. The objective of this study was to use quantitative susceptibility mapping to determine whether lesions with a hyperintense rim, indicative of iron-laden inflammatory cells (rim+), follow a unique time-dependent trajectory of susceptibility change compared with those without (rim-).

MATERIALS AND METHODS

We studied patients with MS with at least 1 new gadolinium-enhancing lesion and at least 3 longitudinal quantitative susceptibility mapping scans obtained between 1.1 and 6.1 years. Lesions were classified as rim+ if a hyperintense rim appeared on quantitative susceptibility mapping at any time. A multilevel growth curve model compared longitudinal susceptibility among rim+ and rim- lesions.

RESULTS

Thirty-two new gadolinium-enhancing lesions from 19 patients with MS were included, and 16 lesions (50%) were identified as rim+. Quantitative susceptibility mapping rim+ lesions were larger than rim- lesions with gadolinium enhancement (P < .001). Among all lesions, susceptibility increased sharply after enhancement to a peak between 1 and 2 years followed by a decrease. The overall susceptibility curve height for rim- lesions was 4.27 parts per billion lower than that for rim+ lesions (P = .01). Rim- lesions demonstrated a higher linear slope relative to rim+ lesions (P = .023) but faster cubic decay relative to rim+ lesions (P = .005). Rim- lesions started decaying approximately 2 years earlier compared with rim+ lesions.

CONCLUSIONS

There was a marked difference in the susceptibility temporal trajectory between rim+ and rim- lesions during the first 6 years of lesion formation. Most rim+ lesions retain iron for years after the initial lesion appearance.

Predictive model of spread of Parkinson's pathology using network diffusion

Growing evidence suggests that a "prion-like" mechanism underlies the pathogenesis of many neurodegenerative disorders, including Parkinson's disease (PD). We extend and tailor previously developed quantitative and predictive network diffusion model (NDM) to PD, by specifically modeling the trans-neuronal spread of alpha-synuclein outward from the substantia nigra (SN). The model demonstrated the spatial and temporal patterns of PD from neuropathological and neuroimaging studies and was statistically validated using MRI deformation of 232 Parkinson's patients. After repeated seeding simulations, the SN was found to be the most likely seed region, supporting its unique lynchpin role in Parkinson's pathology spread. Other alternative spread models were also evaluated for comparison, specifically, random spread and distance-based spread; the latter tests for Braak's original caudorostral transmission theory. We showed that the distance-based spread model is not as well supported as the connectivity-based model. Intriguingly, the temporal sequencing of affected regions predicted by the model was in close agreement with Braak stages III-VI, providing what we consider a "computational Braak" staging system. Finally, we investigated whether the regional expression patterns of implicated genes contribute to regional atrophy. Despite robust evidence for genetic factors in PD pathogenesis, NDM outperformed regional genetic expression predictors, suggesting that network processes are far stronger mediators of regional vulnerability than innate or cell-autonomous factors. This is the first finding yet of the ramification of prion-like pathology propagation in Parkinson's, as gleaned from in vivo human imaging data. The NDM is potentially a promising robust and clinically useful tool for diagnosis, prognosis and staging of PD.

Kinetic control of tunable multi-state switching in ferroelectric thin films

Deterministic creation of multiple ferroelectric states with intermediate values of polarization remains challenging due to the inherent bi-stability of ferroelectric switching. Here we show the ability to select any desired intermediate polarization value via control of the switching pathway in (111)-oriented PbZr_0.2Ti_0.8O₃ films. Such switching phenomena are driven by kinetic control of the volume fraction of two geometrically different domain structures which are generated by two distinct switching pathways: one direct, bipolar-like switching and another multi-step switching process with the formation of a thermodynamically-stable intermediate twinning structure. Such control of switching pathways is enabled by the competition between elastic and electrostatic energies which favors different types of ferroelastic switching that can occur. Overall, our work demonstrates an alternative approach that transcends the inherent bi-stability of ferroelectrics to create non-volatile, deterministic, and repeatedly obtainable multi-state polarization without compromising other important properties, and holds promise for non-volatile multi-state functional applications.

The use of ferroeletric materials for multi-state device applications is still challenging. Here, the authors present a mechanism to stabilize non-volatile polarization states by populating volume fractions of two domain structures in PbZr_0.2Ti_0.8O₃ via kinetic control of switching pathways.

Impact of Induction Chemotherapy on Nodal and Distal Disease Control in Locally Advanced Buccal Mucosa Cancer

Background: Buccal mucosa squamous cell cancer is the most common cancer in India. Majority of them presenting in advanced stage whose prognosis after surgery depends significantly upon the regional and distal spread. We studied the impact of neoadjuvant chemotherapy (NACT) on nodal and distal control of disease in operated cases of advanced buccal mucosa cancer. Aim: A retrospective study to evaluate the impact of induction chemotherapy (NACT) on nodal and distal failure in locally advanced buccal mucosa cancer. Methods: A total of 224 patients of advanced buccal mucosal cancer who underwent surgery between 2014 and 2015 were evaluated retrospectively with a follow-up of two years. Total 111 of the above had received NACT prior to surgery while 113 patients underwent upfront surgery. The CT scans and histologic reports were then compared for evaluation and analysis. Results: Among patients with T4a disease, 45.85% in upfront surgery group compared with 54% in NACT group showed metastatic pathologic nodes, while in T4b patients, the rates were 83.33% compared with 49.18% respectively. In patients with clinical/radiologic positive neck nodes at presentation, 87.5% in upfront surgery group as compared with 55.55% in NACT group showed metastatic nodes in histopathologic evaluation. 13.27% patients in the upfront surgery group had nodal and/or distal failure in the two years follow-up, whereas only 3.6% patients in the NACT group. 25% patients with peri-nodal extension in upfront surgery group showed nodal and/or distal failure, while only 6% in NACT group. The results in different nodal-ratio strata was evaluated. It showed that NACT has equal failure rate as in upfront group in nodal-ratio > 50, which is considered as very advanced and aggressive tumor. But in patients with nodal-ratio < 50, NACT group showed lesser failure rate than upfront group. Conclusion: We show regressional effect of NACT on nodal metastases. This study also shows NACT to be having a significantly positive impact on nodal and distal control. Hence role of induction chemotherapy needs to be considered in advanced cases of buccal mucosa cancer with nodal metastases.

Combining Quantitative Susceptibility Mapping with Automatic Zero Reference (QSM0) and Myelin Water Fraction Imaging to Quantify Iron-Related Myelin Damage in Chronic Active MS Lesions

BACKGROUND AND PURPOSE

A hyperintense rim on susceptibility in chronic MS lesions is consistent with iron deposition, and the purpose of this study was to quantify iron-related myelin damage within these lesions as compared with those without rim.

MATERIALS AND METHODS

Forty-six patients had 2 longitudinal quantitative susceptibility mapping with automatic zero reference scans with a mean interval of 28.9 ± 11.4 months. Myelin water fraction mapping by using fast acquisition with spiral trajectory and T2 prep was obtained at the second time point to measure myelin damage. Mixed-effects models were used to assess lesion quantitative susceptibility mapping and myelin water fraction values.

RESULTS

Quantitative susceptibility mapping scans were on average 6.8 parts per billion higher in 116 rim-positive lesions compared with 441 rim-negative lesions (P < .001). All rim-positive lesions retained a hyperintense rim over time, with increasing quantitative susceptibility mapping values of both the rim and core regions (P < .001). Quantitative susceptibility mapping scans and myelin water fraction in rim-positive lesions decreased from rim to core, which is consistent with rim iron deposition. Whole lesion myelin water fractions for rim-positive and rim-negative lesions were 0.055 ± 0.07 and 0.066 ± 0.04, respectively. In the mixed-effects model, rim-positive lesions had on average 0.01 lower myelin water fraction compared with rim-negative lesions (P < .001). The volume of the rim at the initial quantitative susceptibility mapping scan was negatively associated with follow-up myelin water fraction (P < .01).

CONCLUSIONS

Quantitative susceptibility mapping rim-positive lesions maintained a hyperintense rim, increased in susceptibility, and had more myelin damage compared with rim-negative lesions. Our results are consistent with the identification of chronic active MS lesions and may provide a target for therapeutic interventions to reduce myelin damage.

A Case of Refractory Pulmonary Coccidioidomycosis Successfully Treated with Posaconazole Therapy

Coccidioidomycosis is an endemic fungal infection caused by the inhalation of the spores of Coccidioides species. Patients with underlying immunosuppressive illness can contract chronic or disseminated disease which requires prolonged systemic therapy. Pulmonary coccidioidomycosis remains as an illusory and abstruse disease, with increased prevalence that poses as a challenge for clinicians in developing an effective strategy for treatment. Here, we report successful treatment of a refractory case of chronic relapsing pulmonary coccidioidomycosis in a 50-year old woman with a thin-walled cavitary lung lesion who was ultimately treated with posaconazole.

Relationships among Cortical Glutathione Levels, Brain Amyloidosis, and Memory in Healthy Older Adults Investigated In Vivo with 1H-MRS and Pittsburgh Compound-B PET

BACKGROUND AND PURPOSE

Oxidative stress has been implicated as an important pathologic mechanism in the development of Alzheimer disease. The purpose of this study was to assess whether glutathione levels, detected noninvasively with proton MR spectroscopy, are associated with brain amyloidosis and memory in a community-dwelling cohort of healthy older adults.

MATERIALS AND METHODS

Fifteen cognitively healthy subjects were prospectively enrolled in this study. All subjects underwent 1H-MR spectroscopy of glutathione, a positron-emission tomography scan with an amyloid tracer, and neuropsychological testing by using the Repeatable Battery for the Assessment of Neuropsychological Status. Associations among glutathione levels, brain amyloidosis, and memory were assessed by using multivariate regression models.

RESULTS

Lower glutathione levels were associated with greater brain amyloidosis in the temporal (P = .03) and parietal (P = .05) regions, adjusted for apolipoprotein E ε4 carrier status. There were no significant associations between glutathione levels and cognitive scores.

CONCLUSIONS

This study found an association between cortical glutathione levels and brain amyloidosis in healthy older adults, suggesting a potential role for 1H-MR spectroscopy measures of glutathione as a noninvasive biomarker of early Alzheimer disease pathogenesis.

Highly mobile ferroelastic domain walls in compositionally graded ferroelectric thin films

Domains and domain walls are critical in determining the response of ferroelectrics, and the ability to controllably create, annihilate, or move domains is essential to enable a range of next-generation devices. Whereas electric-field control has been demonstrated for ferroelectric 180° domain walls, similar control of ferroelastic domains has not been achieved. Here, using controlled composition and strain gradients, we demonstrate deterministic control of ferroelastic domains that are rendered highly mobile in a controlled and reversible manner. Through a combination of thin-film growth, transmission-electron-microscopy-based nanobeam diffraction and nanoscale band-excitation switching spectroscopy, we show that strain gradients in compositionally graded PbZr1-xTixO3 heterostructures stabilize needle-like ferroelastic domains that terminate inside the film. These needle-like domains are highly labile in the out-of-plane direction under applied electric fields, producing a locally enhanced piezoresponse. This work demonstrates the efficacy of novel modes of epitaxy in providing new modalities of domain engineering and potential for as-yet-unrealized nanoscale functional devices.

Neurological and endocrine phenotypes of fragile X carrier women

Women who carry fragile X mental retardation 1 (FMR1)gene premutation expansions frequently report neurological or endocrine symptoms and prior studies have predominantly focused on questionnaire report of medical issues. Premutation carrier (PMC) women (n = 33) and non-carrier controls (n = 13) were recruited and evaluated by a neurologist, neuropsychologist, and endocrinologist. Blood and skin biopsies were collected for molecular measures. Scales for movement disorders, neuropathy, cognitive function, psychiatric symptoms, sleep, and quality of life were completed. The average age of the women was 51 years (n = 46) and average CGG repeat size was 91 ± 24.9 in the FMR1 PMC women. Seventy percent of the PMC women had an abnormal neurological examination. PMC women had significantly higher scores on the Fragile X-Associated Tremor Ataxia Syndrome (FXTAS) rating scale, more neuropathy, and difficulty with tandem gait compared to controls. Central sensitivity syndromes, a neuroticism profile on the NEO Personality Profile, and sleep disorders were also prevalent. Discrepancies between subject report and examination findings were also seen. This pilot study suggests that women with the FMR1 premutation may have a phenotype that overlaps with that seen in FXTAS. Additional research with larger sample sizes is warranted to better delineate the clinical features.

Characteristics of the positive ion source at reduced gas feed

The neutral beam injector of steady state superconducting tokamak (SST1-NBI) at IPR is designed for injecting upto 1.7 MW of neutral beam (Hº, 30-55 keV) power to the tokamak plasma for heating and current drive. Operations of the positive ion source (PINI or Plug-In-Neutral-Injector) of SST1-NBI were carried out on the NBI test stand. The PINI was operated at reduced gas feed rate of 2-3 Torr l/s, without using the high speed cryo pumps. Experiments were conducted to achieve a stable beam extraction by optimizing operational parameters namely, the arc current (120-300 A), acceleration voltage (16-40 kV), and a suitable control sequence. The beam divergence, power density profiles, and species fractions (H(+):H2(+):H3(+)) were measured by using the diagnostics such as thermal calorimetry, infrared thermography, and Doppler shift spectroscopy. The maximum extracted beam current was about 18 A. A further increase of beam current was found to be limited by the amount of gas feed rate to the ion source.

Molecular properties and evaluation of indion 234-ondansetron resinates

Ondansetron is a serotonin 5HT3 antagonist; anti-emetic drug. Bitter taste of the ondansetron is a major problem in ensuring patient compliance. The study was designed to formulate tasteless complexes of ondansetron with ion exchange resin and evaluate molecular properties of drug complex. The drug-loading process was carried out using various resins and was optimized using different drug:resin ratio and pH. Resinates were characterized by infrared spectroscopy, thermal analysis, and X-ray powder diffraction (XRPD). Indion 234 gave the best loading efficiency at drug resin ratio of 1:1.5. pH had no effect on drug loading. XRPD studies revealed that drug is in amorphous state in complex. The Infrared studies revealed complexation of secondary amine group of drug with carboxylic functional group of resin. Taste evaluation by using semiquantitative method found resonates as tasteless and agreeable. The release of drug from resinates in simulated gastric fluid was complete in 30 min. Thus, ion exchange resinates offer an effective tool for masking of bitterness and improve drug release.

Cytotoxicity of Ni from Surface-Treated Porous Nitinol (PNT) on Osteoblast Cells

The leaching of nickel from the surface of porous Nitinol (PNT) is mainly dependent on its surface characteristics, which can be controlled by appropriate surface treatments. In this investigation, PNT was subjected to two surface treatments, namely, water-boiling and dry-heating passivations. Phosphate buffer saline (PBS) solutions obtained from cyclic potentiodynamic polarization tests on PNT were employed to assess the cytotoxicity of Ni contained therein on osteoblast cells by Sulforhodamine B (SRB) assay. In addition, similar concentrations of Ni were added exogenously to cell culture media to determine cytotoxic effects on osteoblast cells. The morphologies of the untreated and the surface-treated PNTs were examined using SEM and AFM. Furthermore, growth of human osteoblast cells was observed on the PNT surfaces.

Effect of Manufacturing Process on the Biocompatibility and Mechanical Properties of Ti-30Ta Alloy

Ti alloys have been widely used in the aerospace, chemical, and biomedical industries for their high strength/weight ratio and corrosion resistance. However, Nitinol's usage in the latter industry has been fraught with concerns of allergic and toxic effects of Ni released from implants. Recently, much attention has been placed on the development of Ni-free Ti-Ta alloys, which are considered prime candidates for applications such as metal-on-metal spinal disk replacements, orthopedic implants, cardiovascular stents, dental posts, and guide wires. In this research, the biocompatibility of Ti-30Ta alloys manufactured by powder metallurgy (PM) and arc melting (ARC) were investigated. The corrosion resistance of each alloy was determined in accordance with ASTM F 2129-08 in phosphate buffered saline (PBS) and PBS with amino acids at 37 °C. The concentration of metal ions released during corrosion was measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Scanning Electron Microscopy (SEM) was used to assess the morphology of the alloys before and after corrosion. Vicker's hardness tests were performed to compare the hardness and tensile strength of the alloys. Human osteoblast cells were successfully grown on the surface of both alloys.