A Recent Update on Pathophysiology and Therapeutic Interventions of Alzheimer's Disease

AIM

Alzheimer's disease (AD) has been identified as a progressive brain disorder associated with memory dysfunction and the accumulation of β-amyloid plaques and neurofibrillary tangles of τ protein. Mitochondria is crucial in maintaining cell survival, cell death, calcium regulation, and ATP synthesis. Mitochondrial dysfunction and linked calcium overload have been involved in the pathogenesis of AD. CRM2 (Collapsin response mediator protein-2) is involved in endosomal lysosomal trafficking as well as autophagy, and their reduced level is also a primary culprit in the progression of AD. In addition, Cholinergic neurotransmission and neuroinflammation are two other mechanisms implicated in AD onset and might be protective targets to attenuate disease progression. The microbiota-gut-brain axis (MGBA) is another crucial target for AD treatment. Crosstalk between gut microbiota and brain mutually benefitted each other, dysbiosis in gut microbiota affects the brain functions and leads to AD progression with increased AD-causing biomarkers. Despite the complexity of AD, treatment is only limited to symptomatic management. Therefore, there is an urgent demand for novel therapeutics that target associated pathways responsible for AD pathology. This review explores the role of different mechanisms involved in AD and possible therapeutic targets to protect against disease progression.

BACKGROUND

Amidst various age-related diseases, AD is the most deleterious neurodegenerative disorder that affects more than 24 million people globally. Every year, approximately 7.7 million new cases of dementia have been reported. However, to date, no novel disease-modifying therapies are available to treat AD.

OBJECTIVE

The aim of writing this review is to highlight the role of key biomarker proteins and possible therapeutic interventions that could play a crucial role in mitigating the ongoing prognosis of Alzheimer's disease.

MATERIALS AND METHODS

The available information about the disease was collected through multiple search engines, including PubMed, Science Direct, Clinical Trials, and Google Scholar.

RESULTS

Accumulated pieces of evidence reveal that extracellular aggregation of β-amyloid plaques and intracellular tangles of τ protein are peculiar features of perpetuated Alzheimer's disease (AD). Further, the significant role of mitochondria, calcium, and cholinergic pathways in the pathogenesis of AD makes the respiratory cell organelle a crucial therapeutic target in this neurodegenerative disease. All currently available drugs either delay the clinical damage to cells or temporarily attenuate some symptoms of Alzheimer's disease.

CONCLUSION

The pathological features of AD are extracellular deposition of β-amyloid, acetylcholinesterase deregulation, and intracellular tangles of τ protein. The multifactorial heterogeneity of disease demands more research work in this field to find new therapeutic biological targets.

Green Synthesis and Characterisation of Silver Nanoparticles Using Cassia tora Seed Extract and Investigation of Antibacterial Potential

Nanoparticle research is fascinating and getting hold of consequences due to the wide variety of applications in the biomedical field. Green synthesis of nanoparticles is a cost-effective and eco-friendly approach. It can be synthesised using fungi, algae, plant, yeast, bacteria, microbial enzymes etc. Our current research study focuses on the green synthesis of silver nanoparticles using seed extract of Cassia tora. The colour change from yellow to red colour confirms the formation of silver nanoparticles. The synthesised silver nanoparticles were characterised by Ultraviolet-Visible spectroscopy, Fourier-transform infrared (FTIR), X-ray diffraction analysis (XRD), Scanning Electron Microscopy (SEM) and antibacterial efficacy against three different strains were analysed. The surface plasmon resonance of synthesised AgNPs using Cassia tora seed extract shows maximum absorption peak at 423 nm in UV-visible spectroscopy. X-ray diffraction displays the crystalline nature of synthesised AgNPs and they exhibited four distinct peaks at 36.69°, 42.92°, 63.27° and 76.46°. The particle size of synthesised AgNPs observed through SEM was found to be 55.80 nm, 58.97 nm, 61.06 nm, 63.26 nm and 64.80 nm. S.aureus exhibited maximum zone of inhibition of 12 mm and 13 mm when treated with 25 and 50 μl of the synthesised nanoparticles. Thus, the green synthesised silver nanoparticle using Cassia tora seed extract proved to possess strong anti-bacterial activity.

Incidence of infective endocarditis and its thromboembolic complications in a pediatric population over 30years

BACKGROUND

Pediatric infective endocarditis (IE) has been associated with high morbidity and mortality, mostly related to thromboembolic complications (TEC). The objective of our study was to describe the experience in children with IE and to review the changes over a thirty-year period, regarding origin of IE, incidence of vegetations, TEC and their respective morbidity and mortality rates.

METHODS

A retrospective chart review of children aged 0-18years with IE defined by the Duke Criteria and admitted to The Hospital for Sick Children, was conducted. Data were divided into three periods (P); P1 (1979-1988); P2 (1989-1998); and P3 (1999-2008).

RESULTS

The study included 113 patients, median age 7yrs.; females: 46 (41%), congenital heart defects 95 (84%), comparable in all periods. Overall, cardiac vegetations were found in 68/113 patients (60%); large vegetations (≥1cm) in 32 patients (28%). Fourty-five (45/133 [40%]) TEC were documented, 22 patients (20%) developed cerebrovascular events (CVE) and 23 patients (20%) had non-CVE. Patients diagnosed during P3 were older, had more vegetations (p<0.05), and a higher incidence of community acquired-IE (p<0.05). Overall, mortality was 15%, comparable in all periods. Significant risk factors for mortality were vegetations (HR 6.44; 95% CI: 2.07-20.01, p=0.002) and heart failure (HR 28.39; 95% CI: 10.49-76.85, p<0.001).

CONCLUSIONS

Over the study period, we report a growing incidence of community acquired pediatric IE in older children accompanied by an increasing rate of TEC. Heart failure and vegetations were associated with an increased mortality. These preliminary data need to be confirmed by prospective data.

Stress and Stressors among Medical Undergraduate Students: A Cross-sectional Study in a Private Medical College in Tamil Nadu

Background:

Medical education is perceived as being stressful, and a high level of stress may have a negative effect on cognitive functioning and learning of students in a medical school.

Objectives:

To (a) assess the perceived stress among medical undergraduate students, (b) identify the sources of stress, and (c) find an association of perceived stress with sociodemographic characteristics and various stressors.

Materials and Methods:

A cross-sectional study was conducted among medical undergraduate students in a private medical college in Tamil Nadu. A total of 750 medical students from 1^st year to final year were invited to participate in the study. Self-administered questionnaire was used to collect data regarding sociodemographic profile, perceived stress using perceived stress scale-14 and academic, psychosocial and environmental stressors. Descriptive statistics was used to describe the sociodemographic characteristics, sources of stress and perceived stress. Logistic regression analyses were carried out to assess determinants of stress.

Results:

The overall response rate was 93.33% (700 out of 750 students). The mean perceived stress score was 25.64 ± 5.44. Higher age-group, year of studying bachelor of medicine and bachelor of surgery, vastness of academic curriculum, fear of poor performance in examination, lack of recreation, loneliness, family problem, and accommodation away from home were important determinants of perceived stress.

Conclusions:

The perceived stress was higher among higher age group and final year medical students. Academic, psychosocial, and environmental stressors are associated with perceived stress. Reframing the academic curriculum and examination patterns, incorporating recreational and sports activities, and establishment of counseling cells in the institution is needed.

Role of Community in Swachh Bharat Mission. Their Knowledge, Attitude and Practices of Sanitary Latrine Usage in Rural Areas, Tamil Nadu

BACKGROUND

In most developing countries, open defecation is the 'way of life'. This practice is considered as the most serious health and environmental hazard. Prime Minister of India launched the "Swachh Bharat Mission" to accelerate the efforts for achieving universal sanitation coverage and to put focus on sanitation.

OBJECTIVE

To find the knowledge, attitude and practices of sanitary latrines usage in rural area, Tamil Nadu.

MATERIALS AND METHODS

This was a cross sectional study conducted among rural population in Kuthambakkam village, Tamil Nadu. There were a total of 1175 households in Kuthambakkam village. These households were serially numbered and of these a sample of 275 households were selected for the study using simple random sampling technique by lottery method. A structured questionnaire was used to collect information regarding the background characteristics, their knowledge, attitude and practices towards sanitary latrines usage. Descriptive statistics were calculated for background variables, the prevalence of sanitary latrines usage and open air defecation. Association between factors responsible for open air defecation was found by using chi square test.

RESULTS

The prevalence of usage of household sanitary latrine and community latrines was 62.5% and 4.3% respectively. The prevalence of open air defecation among the study participants was 33.1%.Significant association was found between low standard of living and open air defecation practice.

CONCLUSIONS

To solve the problem of underutilization of sanitary latrines, planning and conducting Information Education Communication activities is very essential. Effective political and administrative support is needed to scale up the sanitation program.

Role of dietary habits and diet in caries occurrence and severity among urban adolescent school children

To identify the role of dietary habits (type of diet, skipping meals, snacking in-between meals and frequency of visits to fast food restaurants) in caries occurrence and severity. To explore the correlation between frequency of intake of selected foods and dental caries. A cross-sectional study was carried out on adolescent children (n = 916) of age 13-19, following a two-stage random sampling technique. Data were collected using a pretested questionnaire. Questionnaire included demographic details, dietary habits of children and food frequency table that listed selected food items. The dependent variable-dental caries was measured using the decayed, missing, filled teeth (DMFT) index. The prevalence of dental caries in this study population was 36.7% (95% confidence interval: 33.58-39.82). The mean DMFT was 1.01 (±1.74). No statistically significant difference found between caries occurrence and type of diet (P = 0.07), skipping meals (P = 0.86), frequency of eating in fast food stalls (0.86) and snacking in between meals (0.08). Mean DMFT values were higher among nonvegetarians and among children who had the habit of snacking in between meals. Frequency of intake of selected food items showed that mean frequency intake of carbonated drinks and confectionery was higher among children who presented with caries when compared to caries-free children (P = 0.000). Significant correlation found between mean DMFT and mean frequency intake of carbonated drinks and confectionery. Odds ratios were calculated for the same for frequency ≥4 times/day for confectionery and ≥4/week for carbonated drinks and results discussed. Frequent intake of carbonated drinks and confectionery is harmful to oral health that eventually reflects on general health. Educating the adolescent children on healthy dietary habits should be put in the forefront.

Pocket Money: Influence on Body Mass Index and Dental Caries among Urban Adolescents

OBJECTIVE

To explore the influence of pocket money on Dental Caries and Body Mass Index.

MATERIALS AND METHODS

A cross-sectional study was conducted wherein urban adolescent schoolchildren of age 13-18(n=916) were selected by two stage random sampling technique. Dental caries was measured using the DMFT Index. The children's nutritional status was assessed by means of anthropometric measurements. Body Mass Index using weight and height of children was evaluated using the reference standard of the WHO 2007.

RESULTS

RESULTS showed that 50% of children receive pocket money from parents. The average amount received was Rs. 360/month. There was a significant correlation between age and amount of money received (r=0.160, p=.001). The average amount received by male children was significantly higher (Rs. 400) when compared to female children (Rs. 303). It was observed that income of the family (>30,000 Rs./month) and socioeconomic status (Upper class) was significantly dependent on the amount of money received by children (p<0.05). There was no significant difference in the occurrence of caries among children receiving pocket money or not. When BMI categories and pocket money were considered, statistically significant difference was seen among overweight and obese and normal weight children (p<.05). Higher proportion (40.1%) of overweight and obese adolescent children frequented the fast food restaurants every week when compared to the underweight (31.7%) and normal weight children (29.9%).

CONCLUSION

Adolescent children receiving pocket money from parents could influence their eating habits in turn affect general health. Parents and teachers should motivate children on healthy spending of their pocket money.