Evaluation of the biocompatibility, antibacterial and anticancer effects of a novel nano-structured Fe-Mn-based biodegradable alloys in-vitro study.

Scientific backgrounds: Development of nanostructured biodegradable alloys has generated a great deal of interest in the recent years as they offer promising bioactive materials for reconstruction of bony defects following traumatic fractures or surgical excision of tumors. Objectives: The aim of the current study was to investigate the biocompatibility of Iron-Manganese -based alloys (Fe-Mn) with addition of copper (Cu), Tungsten (W) and cobalt (Co) to obtain 3 different alloys namely, Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co on normal oral epithelial cell line,and their possible anticancer effect on MG-63: osteosarcoma cell line. Materials and methods: The sulforhodamine B (SRB) assay was used to assess cell viability percentage of both cell lines after exposure to discs of the proposed experimental alloys. Moreover, the antibacterial effect of such alloys against Escherichia coli (E. coli) was tested using disc diffusion susceptibility (Kirby-Bauer method) and colony suspension method. Results: The cell viability percentage of oral epithelial cell line showed a significant increase in all the experimental groups in comparison to the control group. The highest percentage was observed in Fe-Mn-Co group, followed by Fe-Mn-W then Fe-Mn-Cu, at 24 and 72-h intervals, respectively. While the cell viability percentage of osteosarcoma cell line showed significant increase in all the experimental groups at 24-h intervals, it showed a significant drop in all the study groups at 72-h intervals. The lowest percentage was observed in Fe-Mn-Cu group, followed by Fe-Mn-W then Fe-Mn-Co. Moreover, all the examined study groups didn't show any inhibition zones against E. coli reference culture. Conclusions: The novel nanostructured biodegradable Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co metal alloys exhibit good biocompatibility on oral epithelial cell lines with the enhancement of cell proliferation in a time-dependent manner that favors bone regeneration. On the other hand, all the alloys manifested possible anticancer activity against MG-63: osteosarcoma cell line. Furthermore, our study sheds the light on the importance of Co, W and Cu as promising alloying elements. However, the antibacterial activity of the examined alloys is still questionable. Clinical relevance: The novel nanostructured biodegradable Fe-Mn-Cu, Fe-Mn-W, and Fe-Mn-Co metal alloys offer promising bioactive materials for reconstruction of bony defects following traumatic fractures or surgical excision of tumors, In addition, they could be excellent alternatives for undegradable or non-resorbable alloys that are commonly used. Moreover, they could be used as beneficial 3D printing materials to obtain patient-specific medical implants that favor bone regeneration in addition to manufacturing of plates and screws suitable for fracture fixation.

Effect of Al2O3 (x = 0, 1, 2, and 3 vol.%) in CrFeCuMnNi-x High-Entropy Alloy Matrix Composites on Their Microstructure and Mechanical and Wear Performance.

This work aims to study the influence of Al2O3 in CrFeCuMnNi high-entropy alloy matrix composites (HEMCs) on their microstructure, phase changes, and mechanical and wear performances. CrFeCuMnNi-Al2O3 HEMCs were synthesized via mechanical alloying (MA) followed by hot compaction (550 °C at 550 MPa), medium frequency sintering (1200 °C), and hot forging (1000 °C at 50 MPa). The XRD results demonstrate the formation of both FCC and BCC phases in the synthesized powders, which were transformed into major stable FCC and minor ordered B2-BCC phases, as confirmed by HRSEM. The microstructural variation of HRSEM-EBSD, in terms of the coloured grain map (inverse pole figures), grain size distribution, and misorientation angle, was analysed and reported. The grain size of the matrix decreased with the increase in Al2O3 particles owing to the higher structural refinement by MA and zener pinning of the incorporated Al2O3 particles. The hot-forged CrFeCuMnNi-3 vol.% Al2O3 sample exhibited an ultimate compressive strength of 1.058 GPa, which was 21% higher than that of the unreinforced HEA matrix. Both the mechanical and wear performance of the bulk samples increased with an increase in Al2O3 content due to solid solution formation, high configurational mixing entropy, structural refinement, and the effective dispersion of the incorporated Al2O3 particles. The wear rate and coefficient of friction values decreased with the increase in Al2O3 content, indicating an improvement in wear resistance owing to the lower domination of abrasive and adhesive mechanisms, as evidenced by the SEM worn surface morphology.

Long term outcomes after bare metal stent implantation.

Long term outcome data after BMS implant is not available from the Indian subcontinent. This is a prospective observational study which aims to study long term outcomes after BMS implant at a tertiary care centre. 100 consecutive patients underwent BMS implant and were followed up for 20 years. LAD was the most common vessel involved and different types of BMS were implanted. All-cause mortality was noted in 21% (n = 21) whereas cardiac mortality was seen in 16% (n = 16). Cumulative revascularisation free survival at 20 years was 71%. The study showed that long term outcomes after BMS implant were fare and acceptable.

Numerical Simulation on Convection and Thermal Radiation of Casson Fluid in an Enclosure with Entropy Generation.

The goal of the current numerical simulation is to explore the impact of aspect ratio, thermal radiation, and entropy generation on buoyant induced convection in a rectangular box filled with Casson fluid. The vertical boundaries of the box are maintained with different constant thermal distribution. Thermal insulation is executed on horizontal boundaries. The solution is obtained by a finite volume-based iterative method. The results are explored over a range of radiation parameter, Casson fluid parameter, aspect ratio, and Grashof number. The impact of entropy generation is also examined in detail. Thermal stratification occurs for greater values of Casson liquid parameters in the presence of radiation. The kinetic energy grows on rising the values of Casson liquid and radiation parameters. The thermal energy transport declines on growing the values of radiation parameter and it enhances on rising the Casson fluid parameter.

Changing household dietary behaviours through community-based networks: A pragmatic cluster randomized controlled trial in rural Kerala, India.

TRIAL DESIGN: With the rise in prevalence of non-communicable diseases in India and Kerala in particular, efforts to develop lifestyle interventions have increased. However, contextualised interventions are limited. We developed and implemented contextualised behavioural intervention strategies focusing on household dietary behaviours in selected rural areas in Kerala and conducted a community-based pragmatic cluster randomized controlled trial to assess its effectiveness to increase the intake of fruits and vegetables at individual level, and the procurement of fruits and vegetables at the household level and reduce the consumption of salt, sugar and oil at the household level. METHODS: Six out of 22 administrative units in the northern part of Thiruvananthapuram district of Kerala state were selected as geographic boundaries and randomized to either intervention or control arms. Stratified sampling was carried out and 30 clusters comprising 6-11 households were selected in each arm. A cluster was defined as a neighbourhood group functioning in rural areas under a state-sponsored community-based network (Kudumbasree). We screened 1237 households and recruited 479 (intervention: 240; control: 239) households and individuals (male or female aged 25-45 years) across the 60 clusters. 471 households and individuals completed the intervention and end-line survey and one was excluded due to pregnancy. Interventions were delivered for a period of one-year at household level at 0, 6, and 12 months, including counselling sessions, telephonic reminders, home visits and general awareness sessions through the respective neighbourhood groups in the intervention arm. Households in the control arm received general dietary information leaflets. Data from 478 households (239 in each arm) were included in the intention-to-treat analysis, with the household as the unit of analysis. RESULTS: There was significant, modest increase in fruit intake from baseline in the intervention arm (12.5%); but no significant impact of the intervention on vegetable intake over the control arm. There was a significant increase in vegetable procurement in the intervention arm compared to the control arm with the actual effect size showing an overall increase by19%; 34% of all households in the intervention arm had increased their procurement by at least 20%, compared to 17% in the control arm. Monthly household consumption of salt, sugar and oil was greatly reduced in the intervention arm compared to the control arm with the actual effect sizes showing an overall reduction by 45%, 40% and 48% respectively. CONCLUSIONS: The intervention enabled significant reduction in salt, sugar and oil consumption and improvement in fruit and vegetable procurement at the household level in the intervention arm. However, there was a disconnect between the demonstrated increase in FV procurement and the lack of increase in FV intake. We need to explore fruit and vegetable intake behaviour further to identify strategies or components that would have made a difference. We can take forward the lessons learned from this study to improve our understanding of human dietary behaviour and how that can be changed to improve health within this context.

Impact of a community based intervention program on awareness, treatment and control of hypertension in a rural Panchayat, Kerala, India.

OBJECTIVE: Community based intervention to control hypertension is extremely limited in India. We conducted this study to find the effectiveness of a community based intervention program on the awareness, treatment and control of hypertension. METHODS: A baseline survey was conducted among 4627 adults aged ≥30 years (men 44%) selected by cluster sampling. Information was collected using a structured interview schedule by trained local volunteers. They measured weight, height, waist circumference and blood pressure using standard protocol. The volunteers monitored blood pressure at least once a month and educated the people in neighborhood groups on the need for regular medication and reducing risk factors of hypertension for a period of six years. A post intervention survey was conducted among 2263 adults aged ≥30 years (men 49%). Stepwise logistic regression analysis was done to find the odds of change in awareness, treatment and control of hypertension. RESULTS: The odds of awareness (OR 4.18, 95% CI 3.44-5.08), treatment (OR 3.44 CI 2.81-4.22) and control (OR 4.39 CI 3.36-5.73) of hypertension increased significantly in the post intervention survey compared to the baseline survey. Baseline hypertension prevalence of 34.9% (CI 33.8-36.1) was reduced to 31.0% (CI 29.1-32.9) in the post intervention survey based on age adjusted analysis. CONCLUSION: Our community based intervention using trained community based volunteers could increase awareness, treatment and control of hypertension among adult hypertensives.

Design and methodology of a community-based cluster-randomized controlled trial for dietary behaviour change in rural Kerala.

BACKGROUND: Interventions targeting lifestyle-related risk factors and non-communicable diseases have contributed to the mainstream knowledge necessary for action. However, there are gaps in how this knowledge can be translated for practical day-to-day use in complex multicultural settings like that in India. Here, we describe the design of the Behavioural Intervention for Diet study, which was developed as a community-based intervention to change dietary behaviour among middle-income households in rural Kerala. METHODS: This was a cluster-randomized controlled trial to assess the effectiveness of a sequential stage-matched intervention to bring about dietary behaviour change by targeting the procurement and consumption of five dietary components: fruits, vegetables, salt, sugar, and oil. Following a step-wise process of pairing and exclusion of outliers, six out of 22 administrative units in the northern part of Trivandrum district, Kerala state were randomly selected and allocated to intervention or control arms. Trained community volunteers carried out the data collection and intervention delivery. An innovative tool was developed to assess household readiness-to-change, and a household measurement kit and easy formulas were introduced to facilitate the practical side of behaviour change. The 1-year intervention included a household component with sequential stage-matched intervention strategies at 0, 6, and 12 months along with counselling sessions, telephonic reminders, and home visits and a community component with general awareness sessions in the intervention arm. Households in the control arm received information on recommended levels of intake of the five dietary components and general dietary information leaflets. DISCUSSION: Formative research provided the knowledge to contextualise the design of the study in accordance with socio-cultural aspects, felt needs of the community, and the ground realities associated with existing dietary procurement, preparation, and consumption patterns. The study also addressed two key issues, namely the central role of the household as the decision unit and the long-term sustainability through the use of existing local and administrative networks and community volunteers.

Cor triatiratum dexter: a rare cause of isolated right atrial enlargement.

Cor triatriatum sinistrum (division of the left atrium) is a recognized clinical and surgical entity. Division of the right atrium, also known as cor triatriatum dexter, is an extremely rare congenital abnormality in which persistence of the right valve of the embryonic systemic sinus venosus divides the right atrium into two chambers. Typically, the right atrial partition is due to exaggerated fetal eustachian and thebesian valves, which together form an incomplete septum across the lower part of the atrium. This septum may range from a reticulum to a substantial sheet of tissue. Cor triatriatum dexter can be diagnosed at any age, especially if it is incidentally discovered. Usually, this anomaly is recorded at necropsy. This report describes the case of a divided right atrium evaluated for nonspecific symptoms and unexplained cardiomegaly with right atrial enlargement.

Once weekly azithromycin in secondary prevention of rheumatic fever.

Rheumatic fever and rheumatic heart disease (RHD) are still important problems in developing countries. Secondary prophylaxis which is the most cost-effective method in preventing recurrences of rheumatic fever is fraught with problems of drug compliance. The utility of 500 mg once weekly azithromycin (AZT), an orally effective long-acting antibiotic was evaluated against oral penicillin (phenoxy methyl penicillin 250 mg twice daily) in this study. Forty-eight consecutive patients (44% males, mean age 29.4 years) with established RHD were randomised into two groups-26 patients received AZT and 22 received oral penicillin. Patients were evaluated at randomisation, at 1 month, 3 months, and 6 months, clinically, serologically and by throat swab culture. End points were absence of streptococcal colonisation, infection or fever at the end of 6 months. During the study, 4 patients (15.4%) in the AZT group developed sore throat and fever, had positive throat culture and positive serology indicating streptococcal infection. None satisfied the criteria for rheumatic fever reactivation. None in the oral penicillin group developed streptococcal infection. In conclusion, weekly 500 mg of AZT is not effective in the prevention of streptococcal throat infection compared to oral penicillin therapy in adult patients with established RHD.

Left atrial myxoma-influence of tumour size on electrocardiographic findings.

OBJECTIVE: The data of 51 patients (33 females) who underwent excision of left atrial (LA) myxoma were retrospectively reviewed for correlation of tumour size and electrocardiographic (ECG) findings. METHODS AND RESULTS: Mean age was 39.1 ± 15 years (range 9-53 years). The LA enlargement (LAE) on ECG was defined by standard criteria. The LAE in ECG in these patients did not correlate with echocardiographic LA dimensions or with the degree of left ventricular (LV) inflow obstruction. But it was found that the presence of LAE in ECG predicted maximum tumour dimension of >5 cm and correlated with the degree of mitral regurgitation (MR). The LAE in ECG disappeared following surgery in 87.5% of patients. CONCLUSION: The LA enlargement on ECG in a patient with LA myxoma signifies larger tumour size or the presence of significant MR but is not necessarily associated with an increased LA size or LV inflow obstruction.

Usefulness of Doppler derived end diastolic flow gradient across the patent ductus arteriosus in selecting coils for ductal occlusion.

Transcatheter closure of patent ductus arteriosus (PDA) with coils is accepted as an alternative to surgical ligation. We evaluated whether flow gradient across PDA, obtained by Doppler echocardiography, can aid in selecting coils for percutaneous ductal occlusion. 79 consecutive patients with PDA, who underwent successful percutaneous coil occlusion were retrospectively reviewed. Patients with other structural heart disease and pulmonary hypertension with right-to-left shunt were excluded. Echocardiogram and cardiac catheterization were done in all patients. Gianturco (Occluding Spring Emboli; Cook, Bloomington, IN) non-detachable coils of 0.038 and 0.052-inch core sizes were used for ductal occlusion. Trough diastolic gradient was correlated with the size and the number of coils used. Mean age was 8.6 years (range 1.3 to 27 years); 24 males and 55 females; PDA diameter ranged from 1.3 to 4.5 mm. Number of coils used varied from 1 to 4. Echocardiography measured PDA size was 2.5 ± 0.6 mm and significantly differed from angiographically measured size 2.9 ± 0.6 mm (P = 0.05). End diastolic gradient below 38 mmHg predicted use of multiple coils or coils with larger surface area. End diastolic gradient correlated inversely with total surface area of the coils, which indirectly predicted size and number of coils. Thus, the prediction of the size and the number of coils for PDA occlusion can be assisted by the trough diastolic gradients of PDA.

Tropical endomyocardial fibrosis in India: a vanishing disease!

Tropical endomyocardial fibrosis in India was a common medical problem in the coastal districts of south India, especially the Kerala State. The clinical and autopsy studies have shown left and right ventricular apical fibrosis, with varying degree of atrioventricular valve regurgitation. Left ventricular endomyocardial fibrosis presents with severe pulmonary hypertension and right ventricular endomyocardial fibrosis presents very high systemic venous pressure and congestive cardiac failure. Surgical management improved the natural history of the disease to some extent. Various infectious and toxic factors were postulated regarding its aetiology. During the last few years, incidence of the disease has decreased considerably. The only explanation identified is the significant improvement in the living standards of the people with the corresponding decline in the childhood malnutrition, infections, worm infestation and associated eosinophilia.

Percutaneous closure of patent ductus arteriosus in children: Immediate and short-term changes in left ventricular systolic and diastolic function.

OBJECTIVE: To evaluate the effect of percutaneous closure of patent ductus arteriosus (PDA) on left ventricular (LV) systolic and diastolic function in children. BACKGROUND: Limited studies are available on alteration in LV hemodynamics, especially diastolic function, after PDA closure. METHODS: Thirty-two consecutive children with isolated PDA treated by trans-catheter closure were studied. The LV systolic and diastolic function were assessed by two-dimensional (2D) echocardiography and tissue Doppler imaging 1 day before the PDA closure, on day 1, and on follow-up. RESULTS: At baseline, none of the patients had LV systolic dysfunction. On day 1 post-PDA closure, 8 (25%) children developed LV systolic dysfunction. The baseline LV ejection fraction (LVEF), LV end-systolic dimension (LVESD), and PDA diastolic gradient predicted the post-closure LVEF. Patients who developed post-closure LV systolic dysfunction had poorer LV diastolic function than those who did not. LV diastolic properties improved after PDA closure; however, the improvement in LV diastolic properties lagged behind the improvement in the LV systolic function. All children were asymptomatic and had normal LVEF on follow up of >3 months. CONCLUSIONS: Percutaneous closure of PDA is associated with the reversible LV systolic dysfunction. Improvement in the LV diastolic function lags behind that in the LV systolic function.

Trans-catheter closure of atrial septal defect: Balloon sizing or no Balloon sizing - single centre experience.

BACKGROUND: Selecting the device size using a sizing balloon could oversize the ostium secundum atrial septal defect (OSASD) with floppy margins and at times may lead to complications. Identifying the firm margins using trans-esophageal echocardiography (TEE) and selecting appropriate-sized device optimizes ASD device closure. This retrospective study was undertaken to document the safety and feasibility of device closure without balloon sizing the defect. METHODS: Sixty-one consecutive patients who underwent trans-catheter closure of OSASD guided by balloon sizing of the defect and intra procedural fluoroscopy (group I) and 67 consecutive patients in whom TEE was used for defect sizing and as intraprocedural imaging during device deployment (group II) were compared. The procedural success rate, device characteristics, and complications were compared between the two groups. RESULTS: The procedure was successful in 79.7 % patients. The success rate in group II (60 of 67, 89.6%) was significantly higher than in group I (41 of 61, 67.2 %) (P = 0.002). Mean upsizing of ASD device was significantly lower in group II (P < 0.001). TEE also provided better success rate with smaller device in subjects with large ASD (>25 mm) and in those who were younger than 14 years of age. There were four cases of device embolization (two in each group); of which one died in group II despite successful surgical retrieval. CONCLUSION: Balloon sizing may not be essential for successful ASD device closure. TEE-guided sizing of ASD and device deployment provides better success rate with relatively smaller sized device.