Natural Bioactive Compounds from Macroalgae and Microalgae for the Treatment of Alzheimer's Disease: A Review.

Neuroinflammation, toxic protein aggregation, oxidative stress, and mitochondrial dysfunction are key pathways in neurodegenerative diseases like Alzheimer's disease (AD). Targeting these mechanisms with antioxidants, anti-inflammatory compounds, and inhibitors of Aß formation and aggregation is crucial for treatment. Marine algae are rich sources of bioactive compounds, including carbohydrates, phenolics, fatty acids, phycobiliproteins, carotenoids, fatty acids, and vitamins. In recent years, they have attracted interest from the pharmaceutical and nutraceutical industries due to their exceptional biological activities, which include anti-inflammation, antioxidant, anticancer, and anti-apoptosis properties. Multiple lines of evidence have unveiled the potential neuroprotective effects of these multifunctional algal compounds for application in treating and managing AD. This article will provide insight into the molecular mechanisms underlying the neuroprotective effects of bioactive compounds derived from algae based on in vitro and in vivo models of neuroinflammation and AD. We will also discuss their potential as disease-modifying and symptomatic treatment strategies for AD.

Prospecting bioactivity in Antarctic algae: A review of extracts, isolated compounds and their effects.

Algae and its metabolites have been a popular subject of research in numerous fields over the years. Various reviews have been written on algal bioactive components, but a specific focus on Antarctic-derived algae is seldom reviewed. Due to the extreme climate conditions of Antarctica, it is hypothesized that the acclimatized algae may have given rise to a new set of bioactive compounds as a result of adaptation. Although most studies done on Antarctic algae are based on ecological and physiological studies, as well as in the field of nanomaterial synthesis, some studies point out the potential therapeutic properties of these compounds. As an effort to shed light on a different application of Antarctic algae, this review focuses on evaluating its different medicinal properties, including antimicrobial, anticancer, antioxidative, anti-inflammatory, and skin protective effects.

Harnessing Diesel-Degrading Potential of an Antarctic Microalga from Greenwich Island and Its Physiological Adaptation.

Microalgae are well known for their metal sorption capacities, but their potential in the remediation of hydrophobic organic compounds has received little attention in polar regions. We evaluated in the laboratory the ability of an Antarctic microalga to remediate diesel hydrocarbons and also investigated physiological changes consequent upon diesel exposure. Using a polyphasic taxonomic approach, the microalgal isolate, WCY_AQ5_1, originally sampled from Greenwich Island (South Shetland Islands, maritime Antarctica) was identified as Tritostichococcus sp. (OQ225631), a recently erected lineage within the redefined Stichococcus clade. Over a nine-day experimental incubation, 57.6% of diesel (~3.47 g/L) was removed via biosorption and biodegradation, demonstrating the strain's potential for phytoremediation. Fourier transform infrared spectroscopy confirmed the adsorption of oil in accordance with its hydrophobic characteristics. Overall, degradation predominated over sorption of diesel. Chromatographic analysis confirmed that the strain efficiently metabolised medium-chain length n-alkanes (C-7 to C-21), particularly n-heneicosane. Mixotrophic cultivation using diesel as the organic carbon source under a constant light regime altered the car/chl-a ratio and triggered vacuolar activities. A small number of intracellular lipid droplets were observed on the seventh day of cultivation in transmission electron microscopic imaging. This is the first confirmation of diesel remediation ability in an Antarctic green microalga.

Takotsubo cardiomyopathy in the setting of thyroid storm.

A woman in her 50s with a background of chronic obstructive pulmonary disease secondary to smoking presented with intermittent chest tightness, dyspnoea and vomiting for 4 days. A presumed diagnosis of acute coronary syndrome (ACS) was made based on dynamic ischaemic ECG changes and elevation in high-sensitivity cardiac troponin T levels. She underwent emergent coronary angiography which demonstrated mild coronary artery disease with left ventriculography suggestive of mid-wall variant Takotsubo cardiomyopathy. Thyroid function tests performed to investigate sinus tachycardia were consistent with hyperthyroidism, and her thyroid-stimulating hormone receptor antibody was elevated. A diagnosis of thyroid storm was made in the setting of a newly diagnosed Graves' disease and the patient was subsequently commenced on guideline-based therapy. This case demonstrates that Takotsubo cardiomyopathy, a mimic of ACS, is a possible complication of thyroid storm and therefore hyperthyroidism should be considered in the list of differentials in patients presenting with Takotsubo cardiomyopathy.

Oil Palm's Empty Fruit Bunch as a Sorbent Material in Filter System for Oil-Spill Clean Up.

Oil pollution such as diesel poses a significant threat to the environment. Due to this, there is increasing interest in using natural materials mainly from agricultural waste as organic oil spill sorbents. Oil palm's empty fruit bunch (EFB), a cost-effective material, non-toxic, renewable resource, and abundantly available in Malaysia, contains cellulosic materials that have been proven to show a good result in pollution treatment. This study evaluated the optimum screening part of EFB that efficiently absorbs oil and the physicochemical characterisation of untreated and treated EFB fibre using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The treatment conditions were optimised using one-factor-at-a-time (OFAT), which identified optimal treatment conditions of 170 °C, 20 min, 0.1 g/cm3, and 10% diesel, resulting in 23 mL of oil absorbed. The predicted model was highly significant in statistical Response Surface Methodology (RSM) and confirmed that all the parameters (temperature, time, packing density, and diesel concentration) significantly influenced the oil absorbed. The predicted values in RSM were 175 °C, 22.5 min, 0.095 g/cm3, and 10%, which resulted in 24 mL of oil absorbed. Using the experimental values generated by RSM, 175 °C, 22.5 min, 0.095 g/cm3, and 10%, the highest oil absorption achieved was 24.33 mL. This study provides further evidence, as the data suggested that RSM provided a better approach to obtain a high efficiency of oil absorbed.

Potential Application of Algae in Biodegradation of Phenol: A Review and Bibliometric Study.

One of the most severe environmental issues affecting the sustainable growth of human society is water pollution. Phenolic compounds are toxic, hazardous and carcinogenic to humans and animals even at low concentrations. Thus, it is compulsory to remove the compounds from polluted wastewater before being discharged into the ecosystem. Biotechnology has been coping with environmental problems using a broad spectrum of microorganisms and biocatalysts to establish innovative techniques for biodegradation. Biological treatment is preferable as it is cost-effective in removing organic pollutants, including phenol. The advantages and the enzymes involved in the metabolic degradation of phenol render the efficiency of microalgae in the degradation process. The focus of this review is to explore the trends in publication (within the year of 2000-2020) through bibliometric analysis and the mechanisms involved in algae phenol degradation. Current studies and publications on the use of algae in bioremediation have been observed to expand due to environmental problems and the versatility of microalgae. VOSviewer and SciMAT software were used in this review to further analyse the links and interaction of the selected keywords. It was noted that publication is advancing, with China, Spain and the United States dominating the studies with total publications of 36, 28 and 22, respectively. Hence, this review will provide an insight into the trends and potential use of algae in degradation.

A secondary learning curve in 3D versus 2D imaging in laparoscopic training of surgical novices.

BACKGROUND: Stereoscopic (3D) imaging can be used to facilitate the learning of basic laparoscopic tasks. Its advantages over traditional endoscopic (2D) imaging include better depth perception and spatial orientation. However, the transition between 3D and 2D imaging systems has not been previously studied. This study compares the acquisition of basic laparoscopic skills in a laparoscopic-naïve population using both imaging systems, and explores the possibility of a secondary learning curve in the transition between systems. METHODS: 26 novice learners were randomly allocated into two arms and taught to perform two basic laparoscopic tasks adopted from the fundamentals of laparoscopic surgery (FLS) curriculum, peg transfer (T1) and pattern cutting (T2) using either 2D or 3D imaging systems. These tasks were repeated until proficiency was achieved. Participants in each arm then repeated the tasks in the other viewing system (2D/3D vs 3D/2D). The parameters measured were: (a) time taken to complete the task and (b) number of attempts to achieve proficiency. RESULTS: There was a significant shortening of time required to achieve proficiency in T2 using a 3D system (mean difference-in-differences = - 65.4, 95% CI - 103.6 to - 27.2, t(24) = - 3.5, p value = 0.002) but no difference between 2D and 3D imaging systems for T1, a simpler task. Sub-group analysis of T1 and T2 between the 2D/3D and 3D/2D arms showed the presence of a secondary learning curve in the 2D/3D arm for both tasks, (T1: ß-estimate - 2.68, 95% CI - 3.68 to - 1.68, p value = 0.0003; T2: ß-estimate - 2.45, 95% CI - 3.75 to - 1.14, p value 0.004), but in the 3D/2D arm there was a secondary learning curve only for T2. (ß-estimate 2.60, 95% CI 1.45-3.76, p value 0.001) CONCLUSION: 3D imaging can be an effective tool to speed the acquisition of proficiency in basic laparoscopic tasks for novice learners, especially in more complex tasks such as pattern cutting. The skills learned in 3D imaging can translate into 2D, albeit with a secondary learning curve.

Myocardial Infarction in the "Young": Risk Factors, Presentation, Management and Prognosis.

Myocardial infarction (MI) in the "young" is a significant problem, however there is scarcity of data on premature coronary heart disease (CHD) and MI in the "young". This may lead to under-appreciation of important differences that exist between "young" MI patients versus an older cohort. Traditional differences described in the risk factor profile of younger MI compared to older patients include a higher prevalence of smoking, family history of premature CHD and male gender. Recently, other potentially important differences have been described. Most "young" MI patients will present with non-ST elevation MI but the proportion presenting with ST-elevation MI is increasing. Coronary angiography usually reveals less extensive disease in "young" MI patients, which has implications for management. Short-term prognosis of "young" MI patients is better than for older patients, however contemporary data raises concerns regarding longer-term outcomes, particularly in those with reduced left ventricular systolic function. Here we review the differences in rate, risk factor profile, presentation, management and prognosis between "young" and older MI patients.

Interactive Effects of Temperature and UV Radiation on Photosynthesis of Chlorella Strains from Polar, Temperate and Tropical Environments: Differential Impacts on Damage and Repair.

Global warming and ozone depletion, and the resulting increase of ultraviolet radiation (UVR), have far-reaching impacts on biota, especially affecting the algae that form the basis of the food webs in aquatic ecosystems. The aim of the present study was to investigate the interactive effects of temperature and UVR by comparing the photosynthetic responses of similar taxa of Chlorella from Antarctic (Chlorella UMACC 237), temperate (Chlorella vulgaris UMACC 248) and tropical (Chlorella vulgaris UMACC 001) environments. The cultures were exposed to three different treatments: photosynthetically active radiation (PAR; 400-700 nm), PAR plus ultraviolet-A (320-400 nm) radiation (PAR + UV-A) and PAR plus UV-A and ultraviolet-B (280-320 nm) radiation (PAR + UV-A + UV-B) for one hour in incubators set at different temperatures. The Antarctic Chlorella was exposed to 4, 14 and 20°C. The temperate Chlorella was exposed to 11, 18 and 25°C while the tropical Chlorella was exposed to 24, 28 and 30°C. A pulse-amplitude modulated (PAM) fluorometer was used to assess the photosynthetic response of microalgae. Parameters such as the photoadaptive index (Ek) and light harvesting efficiency (α) were determined from rapid light curves. The damage (k) and repair (r) rates were calculated from the decrease in ΦPSIIeff over time during exposure response curves where cells were exposed to the various combinations of PAR and UVR, and fitting the data to the Kok model. The results showed that UV-A caused much lower inhibition than UV-B in photosynthesis in all Chlorella isolates. The three isolates of Chlorella from different regions showed different trends in their photosynthesis responses under the combined effects of UVR (PAR + UV-A + UV-B) and temperature. In accordance with the noted strain-specific characteristics, we can conclude that the repair (r) mechanisms at higher temperatures were not sufficient to overcome damage caused by UVR in the Antarctic Chlorella strain, suggesting negative effects of global climate change on microalgae inhabiting (circum-) polar regions. For temperate and tropical strains of Chlorella, damage from UVR was independent of temperature but the repair constant increased with increasing temperature, implying an improved ability of these strains to recover from UVR stress under global warming.

Effect of iron chelation on myocardial infarct size and oxidative stress in ST-elevation-myocardial infarction.

BACKGROUND: Experimental studies suggest that deferoxamine (DFO) limits the generation of reactive oxygen species by chelating redox-active iron and thereby may reduce ischemia-reperfusion injury and myocardial infarct (MI) size. We investigated whether DFO administered before reperfusion by primary percutaneous coronary intervention (PPCI) would ameliorate oxidative stress and MI size. METHODS AND RESULTS: We randomly assigned 60 patients with ST-elevation-MI to receive an intravenous bolus of DFO (500 mg) immediately before PPCI followed by a 12-hour infusion (50 mg/kg of body weight) (n=28) or normal saline bolus and infusion (placebo group, n=32). MI size was measured by contrast-enhanced cardiac MRI (CMRI; day 3±1), creatine kinase and troponin I area-under-the-curve, and severity of wall motion abnormality on echocardiography. Clinical follow-up including repeat CMRI and echocardiography were performed at 3 months (100±17 days). Oxidative stress was assessed by plasma F(2)-isoprostane levels. DFO and placebo groups were well balanced with respect to baseline characteristics, symptom- and door-to-balloon times, pre-PPCI coronary patency, and infarct-related artery location. Serum iron levels were decreased with DFO treatment after PPCI compared with placebo (3.0±2.5 versus 12.6±5.5 µmol/L, P<0.0001), which persisted until the end of the infusion. In DFO-treated patients, there was a significant reduction in plasma F(2)-isoprostane levels immediately after PPCI (2878±1461 versus 2213±579 pmol/L, P=0.04). However, there was no difference in CMRI-determined infarct size (DFO, 17.4±10.8%, versus placebo, 18.6±10.2%; P=0.73), myocardial salvage index at 3 days or at 3 months, or the area-under-the-curve for creatine kinase or troponin I. CONCLUSIONS: Adjunctive DFO treatment after the onset of ischemia and continued periprocedurally ameliorates oxidative stress without limiting infarct size. CLINICAL TRIAL REGISTRATION: URL: http://www.anzctr.org.au/. Unique identifier: ACTRN12608000308392.

Selective activation of the "b" splice variant of phospholipase Cbeta1 in chronically dilated human and mouse atria.

Atrial fibrillation (AF) is commonly associated with chronic dilatation of the left atrium, both in human disease and animal models. The immediate signaling enzyme phospholipase C (PLC) is activated by mechanical stretch to generate the Ca2+-releasing messenger inositol(1,4,5)trisphosphate (Ins(1,4,5)P3) and sn-1,2-diacylglycerol (DAG), an activator of protein kinase C subtypes. There is also evidence that heightened activity of PLC, caused by the receptor coupling protein Gq, can contribute to atrial remodelling. We examined PLC activation in right and left atrial appendage from patients with mitral valve disease (VHD) and in a mouse model of dilated cardiomyopathy caused by transgenic overexpression of the stress-activated protein kinase, mammalian sterile 20 like kinase 1 (Mst1) (Mst1-TG). PLC activation was heightened 6- to 10-fold in atria from VHD patients compared with right atrial tissue from patients undergoing coronary artery bypass surgery (CABG) and was also heightened in the dilated atria from Mst1-TG. PLC activation in human left atrial appendage and in mouse left atria correlated with left atrial size, implying a relationship between PLC activation and chronic dilatation. Dilated atria from human and mouse showed heightened expression of PLCbeta1b, but not of other PLC subtypes. PLCbeta1b, but not PLCbeta1a, caused apoptosis when overexpressed in neonatal rat cardiomyocytes, suggesting that PLCbeta1b may contribute to chamber dilatation. The activation of PLCbeta1b is a possible therapeutic target to limit atrial remodelling in VHD patients.

Obesity cardiomyopathy: diagnosis and therapeutic implications.

Obesity is associated with an increased risk of heart failure. Apparently healthy obese individuals can, however, exhibit subclinical left ventricular dysfunction. The use of myocardial imaging techniques to detect this subclinical change could have important management implications with respect to initiating prophylactic therapy. In this Review, we evaluate possible pharmacologic and nonpharmacologic strategies for treating obesity cardiomyopathy in the context of currently understood mechanisms, including myocardial remodeling and small vessel disease, and more speculative mechanisms such as insulin resistance, and activation of the renin-angiotensin-aldosterone and sympathetic nervous systems.