Shape and size control of nano dispersed Mg/Al layered double hydroxide

Controlling the shape and size of the layered inorganic-organic hybrid particles is a challenge with conventional methods of synthesis. The co-precipitation method has been modified to synthesize Mg/Al Layered double hydroxide by controlling the particle growth using ultrasonic wave at the time of nucleation. In this project, magnesium and aluminum ions were considered as model systems with carbonate anion as intercalating agent. The resulting particles are compared with those of LDHs produced by conventional co-precipitation method at constant pH. Powder X-ray diffraction confirmed formation of the layered double hydroxide phases having crystallite size 19-20 nm in both 'a' and 'c' crystallographic directions. Transmission electron microscope and dynamic light scattering revealed nano disperse hexagonal platelets with narrow size distribution and average size was around 48 nm. The modified method reduces the particle size, increases the surface charge, narrows down the size distribution and also reduces the aspect ratio of the particles. Therefore, it is suggested that low amplitude ultrasonic wave prevents the aggregation of the nuclei, thus restricting the particle growth and results in uniform size particles.

Medical physics aspects of cancer care in the Asia Pacific region

Medical physics plays an essential role in modern medicine. This is particularly evident in cancer care where medical physicists are involved in radiotherapy treatment planning and quality assurance as well as in imaging and radiation protection. Due to the large variety of tasks and interests, medical physics is often subdivided into specialties such as radiology, nuclear medicine and radiation oncology medical physics. However, even within their specialty, the role of radiation oncology medical physicists (ROMPs) is diverse and varies between different societies. Therefore, a questionnaire was sent to leading medical physicists in most countries/areas in the Asia/Pacific region to determine the education, role and status of medical physicists.Answers were received from 17 countries/areas representing nearly 2800 radiation oncology medical physicists. There was general agreement that medical physicists should have both academic (typically at MSc level) and clinical (typically at least 2 years) training. ROMPs spent most of their time working in radiotherapy treatment planning (average 17 hours per week); however radiation protection and engineering tasks were also common. Typically, only physicists in large centres are involved in research and teaching. Most respondents thought that the workload of physicists was high, with more than 500 patients per year per physicist, less than one ROMP per two oncologists being the norm, and on average, one megavoltage treatment unit per medical physicist.There was also a clear indication of increased complexity of technology in the region with many countries/areas reporting to have installed helical tomotherapy, IMRT (Intensity Modulated Radiation Therapy), IGRT (Image Guided Radiation Therapy), Gamma-knife and Cyber-knife units. This and the continued workload from brachytherapy will require growing expertise and numbers in the medical physics workforce. Addressing these needs will be an important challenge for the future.

Radiotherapy for benign diseases

Radiotherapy mainly involves treatment of patients with malignant tumors. Even with recognition of the risks of late skin injury, carcinogenesis, leukemogenesis, and genetic damage from all ionizing radiation; radiation therapy also continues to be accepted treatment for benign diseases. Before initiation, the quality of irradiation, total dose, overall time, underlying organs at risk, and shielding factors should be considered. Children should be treated with ionizing radiation only in very exceptional cases and after weighing the pros and cons of the therapy. Direct irradiation of skin areas overlying organs that are particularly prone to late effects (e.g. thyroid, eye, gonads, bone marrow and breast) should be avoided. Radiation protection techniques should be used in all instances. The depth of penetration of the x-ray beam should be chosen according to the depth of the pathologic process. Choice of beam energy usually depends on the depth of the target volume; every effort is made to spare normal underlying tissue in superficial lesions. There are a number of other benign conditions that can be treated with radiotherapy; we present a brief overview of some of the commonly encountered conditions.

Annual risk of tuberculous infection in Andhra Pradesh, India

BACKGROUND

There is paucity of information on epidemiological situation of Tuberculosis (TB) in Andhra Pradesh. The DOTS strategy under the Revised National Tuberculosis Control Programme (RNTCP) was introduced in the year 2000 to cover the entire State by 2005.

OBJECTIVES

To estimate the prevalence of tuberculous infection among children 5-9 years of age and to compute the average Annual Risk of Tuberculosis Infection (ARTI) from the estimated prevalence.

METHODS

A cluster-sample house-based tuberculin survey was carried out in a representative sample of children between 5-9 years of age. The clusters were selected by a two-stage sampling procedure. At first stage, five districts were selected by probability proportional to population size (PPS) method. Depending upon child population ratio, 32 clusters allocated to each district were further sub-divided into rural and urban clusters selected by simple random sampling. A total of 3636 children, irrespective of their BCG scar status, were tuberculin tested using one TU PPD RT23 with Tween 80 and the maximum transverse diameter of induration was measured about 72 hours later.

RESULTS

The prevalence of infection estimated by mirror-image technique using observed mode of reactions attributable to infection with tubercle bacilli at 20mm was 9.6% (95% CI: 8.0-11.2). The ARTI was computed at 1.4% (95% CI: 1.1-1.6).

CONCLUSION

Survey findings indicate a fairly high rate of transmission of tubercle bacilli.

Evaluation of four airway training manikins as patient simulators for the insertion of single use laryngeal mask airways

We evaluated the performance of four manikins: Airsim(trade mark), Bill 1, Airway Management Trainer and Airway Trainer, as simulators for insertion of single-use laryngeal mask airways and the reusable LMA Classic. Sixteen volunteer anaesthetists inserted each laryngeal mask airway into each manikin twice. Insertions were scored for ease of insertion, clinical and fibreoptic position, and lung ventilation (maximum score 10). Scores < 7 were classified 'poor' and < 5 'failure'. We analysed manikin and laryngeal mask airway performance. Poor insertion rate was 15% (range 9-21%) and was lowest for the VBM manikin (p = 0.02). Insertion failure rate was 2.6% and did not differ significantly between manikins (p = 0.2). Overall manikin performance was significantly different (p < 0.0001). The VBM manikin scored best, with all other manikins equivalent. The VBM manikin performed significantly better for three individual laryngeal mask airways. Overall performance differences of laryngeal mask airways were statistically significant (p < 0.001) but individual comparisons were not. Silicone devices performed better than PVC devices (p < 0.05) Devices with and without grilles performed similarly. All manikins were adequate. The VBM manikin performed best overall and for several individual laryngeal mask airways. The methodology is useful for future evaluations of devices, both manikins and supraglottic airways. Further human clinical research is required.

Mucositis in cancer patients: Prototypic semi-mechanistic kinetic model

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Background: Recent research advances have helped (i) define pathobiology of alimentary tract mucosal injury secondary to cancer therapy and (ii) link molecular mechanisms with clinically important outcomes. Recently-developed computational biology modeling may further enhance these advances. Semi-mechanistic (SM) modeling allows one to approach quantitative analysis of a biochemical system that is incompletely determined. In this study, data from sequential oral mucosal biopsies in 3 patients developing oral mucositis secondary to hematopoietic stem cell transplantation (HSCT) conditioning were utilized to establish a prototypic computational model for this toxicity. Methods: Plasma and oral mucosal biopsy specimens were obtained from 3 autologous HSCT patients before and after administration of conditioning chemotherapy: Day -10, +10, +28 and +100; Day 0 was day of transplant. Full-thickness tissue samples were measured by RT- PCR for COX-1, COX-2, IL-1β and TNF-a. Plasma samples were measured by ELISA for PGE2 and PGI2, markers of COX-2 activity. The SM model was implemented as a system of 6 ordinary differential equations with 15 parameters. Parameter estimation and simulations were conducted based on experimental results, using a combination of Mathematica, Berkeley Madonna and Virtual Cell software packages. Results: The SM model captured the behavior of COX-1, IL-1β and PGE2 dynamics, predicting an exponential decay for each of these species. Half-lives relative to average steady-state values were found to be 9.7 days, 8.7 days and 9.3 days for COX-1, IL-1β and PGE2 respectively. Correlation ratios for each of these species were calculated to be 0.62, 0.61 and 0.90 respectively. Conclusions: This prototypic model provides a basis for development of a detailed mathematical model for quantifying relevant components of the mucositis pathway. This combination of modeling and experiment could also identify gaps in the pathway that would be important targets for new hypotheses, including possible feedback mechanisms relative to inflammatory cytokines.

No significant financial relationships to disclose.

A rare case of metabolic bone disease

A 26-year-old female overseas student was admitted to hospital with a fracture of her left humerus following minimal trauma. Biochemical abnormalities included hypercalcaemia, hypophosphataemia, raised alkaline phosphatase, raised parathyroid hormone and undetectable 25-hydroxy-vitamin D. Skeletal X-rays revealed multiple osteolytic lesions in the humerus as well as similar lesions in the femora and pelvis. Magnetic resonance imaging of her left shoulder showed a large soft tissue mass in the proximal humerus. Bone biopsy was reported as consistent with a brown tumour of primary hyperparathyroidism and a sestamibi scan confirmed the presence of a parathyroid adenoma. However, the isotope bone scan was reported as showing features typical of fibrous dysplasia involving multiple sites. The patient subsequently fractured her right femoral shaft, and a femoral nail was inserted. Parathyroidectomy was performed at the same time. Postoperatively she exhibited increased calcium and vitamin D requirements. Coexistence of primary hyperparathyroidism and polyostotic fibrous dysplasia is very rare.

Application of self-assembled ultra-thin film coatings to stabilize macromolecule encapsulation in alginate microspheres

Alginate-based hydrogels have several unique properties that have enabled them to be used as a matrix for the entrapment of a variety of enzymes, proteins and cells for applications in bioprocessing, drug delivery and chemical sensing. However, control over release rates or, in some cases, stable encapsulation remains a difficult goal, especially for small particles with high surface-area-to-volume ratios. In this work, the potential to limit diffusion of macromolecules embedded in alginate spheres with nanofilm coatings was assessed. Alginate microspheres were fabricated using an emulsification process with high surfactant concentration to form beads in the size range of 2-10 microm. Using calcium chloride for ionotropic gelation, dextran was encapsulated in the gel phase by mixing with the alginate in solution. The exterior surface was then modified with polyelectrolyte coatings using the layer-by-layer self assembly technique. Leaching studies to assess retention of dextran with varying molecular weights confirmed that the application of multi-layer thin films to the alginate microspheres was effective in reducing leaching rate and total loss of the encapsulated material from the microspheres. For the best case, the rate of release for dextran of 2,000,000 Dalton molecular weight decreased from 1% h(-1) in bare microspheres to 0.1% h(-1) in polyelectrolyte-coated microspheres. The effectiveness of nanofilms reducing loss of the encapsulated macromolecules was found to vary between different polycation materials used. These studies support the feasibility of using these microsystems for development of long-term stable encapsulated systems, such as implantable biosensors.

Salicylic acid content of spices and its implications

This work was done to determine the salicylate content of a variety of commonly used spices and to assess whether this potential dietary source of salicylate was bioavailable. Spices, Indian cooked dishes, and blood and urine samples taken after ingestion of a test meal were investigated for their salicylate content using high-performance liquid chromatography with electrochemical detection. The serum salicylic acid concentrations in samples from villagers in southern India were also measured and have been compared with typical European values. Salicylic acid was determined in all spices (up to 1.5 wt %) and cooked dishes. The salicylate content of blood and urine was shown to increase following consumption of the meal, indicating that this dietary source of salicylic acid was bioavailable. Salicylic acid levels in the serum from rural Indians were significantly (median almost 3-fold) higher than values previously measured in Western vegetarians. Chemoprotective aspirin is rapidly hydrolyzed to salicylic acid, and this phytochemical may contribute to the low cancer incidence in rural India.

Curative interstitial brachytherapy for early stage carcinoma lip

Brachytherapy is potentially useful in the treatment of head-and-neck cancers, because most tumor sites, such as the lip, tongue, floor of mouth, tonsil, pharynx, nasopharynx, sinuses, and neck, are accessible for the placement of afterloading applicators and catheters. It has the advantage of delivering a higher radiation dose to the tumor while sparing surrounding normal tissue from radiation. Furthermore, the overall treatment duration is shorter, and the dose distribution confirms to tumor shape. Brachytherapy is used as "monotherapy" for the treatment of small primary tumors or recurrent disease after external beam radiation therapy (EBRT). Small cancers of the lip (less than 2 cm) are treated equally well with surgery or radiation therapy with excellent cosmetic and functional results seen in radiation therapy. We treated an 18-year old male diagnosed as stage I carcinoma lip with curative interstitial brachytherapy. He was treated to a dose of 3 Gy per fraction, two fractions per day at interval of 6 hours between the two fractions for 6 days. He therefore received a total dose of 36 Gy with High Dose Rate (HDR) Brachytherapy, which is equivalent to 58.36 Gy conventional radiotherapy dose. At two months follow, the patient is clinically disease free and has no complaints.

Indian Society for Apheresis and apheresis tourism in India – Is there a future?

Apheresis has now become an internationally popular mode of treatment for multiple immune complex disorders. However, the treatment remains quite expensive in Western Europe and the US. Apheresis tourism is a part of medical tourism or medical tourism specially related to therapeutic apheresis (TA) treatment in a foreign country on a cost effective basis. In the last couple of years, 'Medical Tourism' has become an upcoming and growing enterprise in India. The Indian Society for Apheresis (ISA) has taken a plunge at the opportune time and is trying to promote apheresis tourism in India. ISA is a member of various international apheresis organizations globally including the World Apheresis Association (WAA), the International Society for Apheresis (ISFA), the International Society for Artificial Organs (ISAO) and an associate of other national apheresis societies. The Indian Society for Apheresis (ISA) and the Ludhiana MediCiti (LMC) at Ludhiana Punjab are taking a big step in this direction. The therapeutic apheresis (TA) center at LMC is being set up as a Therapeutic Apheresis Institute and Research Center of excellence. The potential future impacts on the apheresis scenario are summarized.

Methylenetetrahydrofolate reductase gene polymorphism in Indian stroke patients

BACKGROUND AND AIMS

In view of the prevailing controversy about the role of Methylenetetrahydrofolate reductase (MTHFR) C677T mutation in stroke and paucity of studies from India, this study has been undertaken to evaluate MTHFR C677T gene polymorphism in consecutive ischemic stroke patients and correlate these with folic acid, homocysteine (Hcy) and conventional risk factors.

SETTINGS AND DESIGN

Ischemic stroke patients prospectively evaluated in a tertiary care teaching hospital.

MATERIALS AND METHODS

Computerized tomography proven ischemic stroke patients were prospectively evaluated including clinical, family history of stroke, dietary habits and addictions. Their fasting and postprandial blood sugar, lipid profile, vitamin B12, folic acid and MTHFR gene analysis were done.

STATISTICAL ANALYSIS

MTHFR gene polymorphism was correlated with serum folic acid, Vitamin B12 and Hcy levels; family history of stroke in first-degree relatives; and dietary habits; employing Chi-square test.

RESULTS

There were 58 patients with ischemic stroke, whose mean age was 50 (4-79) years; among them, 10 were females. MTHFR gene polymorphism was present in 19 (32.8%) patients, 3 were homozygous and 16 were heterozygous. Both serum folate and B12 levels were low in 29 (50%) patients and Hcy in 48 (83%). Hypertension was present in 28 (48%) patients, diabetes in 12 (21%), hyperlipidemia in 52 (90%), smoking in 17 (29%), obesity in 1 (1.7%) and family history of stroke in first-degree relatives in 13 (22.4%). There was no significant relationship of MTHFR gene polymorphism with folic acid, B12, Hcy levels, dietary habits and number of risk factors. Vitamin B12 level was low in vegetarians (P<0.003). In 3 patients with MTHFR TT alleles, Hcy was elevated in all 3, low folic acid in 2 and family history of stroke in 1 patient.

CONCLUSION

MTHFR gene polymorphism was found in one-third of patients with ischemic stroke and was insignificantly associated with higher frequency of elevated Hcy.

Synthesis and antitubercular activities of bis-glycosylated diamino alcohols

Conjugate addition of diamines to glycosyl olefinic esters 1a and 1b followed by reduction of resulting bis-glycosyl beta-amino esters (2-7 and 14-19) with lithium aluminium hydride led to the respective glycosyl amino alcohols (8-13 and 20-25) in moderate to good yields. All the compounds were evaluated for antitubercular activity against Mycobacterium tuberculosis H(37)Ra and H(37)Rv. Few of the compounds exhibited antitubercular activity with MIC as low as 6.25-3.12microg/mL in virulent and avirulent strains. Compound 13 was found to be active against MDR strain and showed mild protection in mice.