Melatonin in Alzheimer's disease and other neurodegenerative disorders

Increased oxidative stress and mitochondrial dysfunction have been identified as common pathophysiological phenomena associated with neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD). As the age-related decline in the production of melatonin may contribute to increased levels of oxidative stress in the elderly, the role of this neuroprotective agent is attracting increasing attention. Melatonin has multiple actions as a regulator of antioxidant and prooxidant enzymes, radical scavenger and antagonist of mitochondrial radical formation. The ability of melatonin and its kynuramine metabolites to interact directly with the electron transport chain by increasing the electron flow and reducing electron leakage are unique features by which melatonin is able to increase the survival of neurons under enhanced oxidative stress. Moreover, antifibrillogenic actions have been demonstrated in vitro, also in the presence of profibrillogenic apoE4 or apoE3, and in vivo, in a transgenic mouse model. Amyloid-β toxicity is antagonized by melatonin and one of its kynuramine metabolites. Cytoskeletal disorganization and protein hyperphosphorylation, as induced in several cell-line models, have been attenuated by melatonin, effects comprising stress kinase downregulation and extending to neurotrophin expression. Various experimental models of AD, PD and HD indicate the usefulness of melatonin in antagonizing disease progression and/or mitigating some of the symptoms. Melatonin secretion has been found to be altered in AD and PD. Attempts to compensate for age- and disease-dependent melatonin deficiency have shown that administration of this compound can improve sleep efficiency in AD and PD and, to some extent, cognitive function in AD patients. Exogenous melatonin has also been reported to alleviate behavioral symptoms such as sundowning. Taken together, these findings suggest that melatonin, its analogues and kynuric metabolites may have potential value in prevention and treatment of AD and other neurodegenerative disorders

PENGARUH PEMBERIAN INFORMASI METODE RICE TERHADAP TINGKAT PENGETAHUAN PENANGANAN DINI CEDERA PADA PEMAIN FUTSAL

Cedera kaki terkilir merupakan salah satu trauma yang disebabkan oleh tekanan rendah yang berulang-ulang dalam jangka waktu yang lama. Tujuan penelitian ini adalah untuk mengidentifikasi dan menganalisa pengaruh Metode Rest, Ice, Compression dan Elevation (RICE) terhadap tingkat pengetahuan dan penanganan dini cedera terkilir pada pemain Futsal. Jenis penelitian ini merupakan jenis penelitian Pre-eksperimental dengan rancangan one-group pre-post test design. Sampel pada penelitian ini adalah pemain Futsal dengan tehnik Accidental Sampling sebanyak 30 responden yang memenuhi kriteria inklusi. Alat ukur yang digunakan adalah kuisioner pengetahuan yang dikembangkan oleh peneliti (telah dilakukan uji valid dan reliable). Hasil penelitian sebelum dilakukan Metode rice pada pemain Futsal kategori kurang sebanyak 30 responden (100%), setelah diberikan informas Metode Rice dalam bentuk media seperti leaflet keseluruhan pemain Futsal ialah baik sebanyak 30 responden (100%). Uji Analisis statistik Wilcoxon. di dapatkan nilai p=0,000 0,05. Kesimpulan pada penelitian ada pengaruh antara Metode RICE terhadap tingkat pengetahuan penanganan dini cedera pada pemain Futsal. Metode RICE direkomendasikan untuk dikuasai oleh seluruh pemain Futsal sebagai tindakan awal dalam mengatasi cedera

Kajian Sikap dan Perilaku Konsumen dalam Pembelian Kopi Serta Pendapatnya terhadap Varian Produk dan Potensi Kedainya

Tingginya tingkat konsumsi kopi yang ada di Indonesia membuat peluang bagi banyak pelaku USAha kedai kopi untuk mengembangkan USAhanya. Penelitian ini bertujuan untuk melihat bagaimana sikap dan perilaku konsumen terhadap pembelian kopi yang mereka lakukan di Armor Kopi Garden, Bandung. Metode analisis data yang digunakan adalah theory of reasoned action dari Fishbein yang terdiri dari sikap dan perilaku konsumen dengan sampel sebanyak 95 orang. Atribut yang digunakan dalam penelitian ini adalah rasa, variasi menu, desain produk, layanan pelengkap, harga, dan promosi. Hasil analisis menunjukan bahwa konsumen yang datang rata-rata adalah laki-laki berstatus mahasiswa/i. Alasan mereka datang ke kedai kopi yang paling dominan adalah karena suasana yang nyaman (44%), kemudian keinginan untuk sekedar mencoba (22%) lalu karena faktor rasanya yang khas (10%) dan berbagai alasan lainnya (22%). Sikap konsumen terhadap pembelian produk kopi secara keseluruhan menunjukan hasil yang baik. Sikap yang dianggap paling baik ada pada atribut desain produk dan yang dianggap paling tidak baik ada pada atribut promosi. Hasil analisis perilaku konsumen di Armor Kopi Garden berdasarkan angka skor rata-rata menunjukan bahwa yang berperan paling dominan dalam membuat keputusan konsumen adalah teman dan media sedangkan skor yang terendah ada pada keluarga. Potensi yang dimiliki antara lain produk yang beragam, fasilitas yang lengkap, serta barista yang handal. Kedala yang dimiliki dalam menjalankan USAha adalah adalah adanya competitor yaitu Armor Kopi Tahura yang menyebabkan pengunjung terbagi-bagi

Austenite to ferrite transformation kinetics during continuous cooling

The austenite decomposition has been investigated in a hypo-eutectoid plain carbon steel under continuous cooling conditions using a dilatometer and a Gleeble 1500 thermomechanical simulator. The experimental results were used to verify model calculations based on a fundamental approach for the dilute ternary systems Fe-C-Mn. The austenite to ferrite transformation start temperature can be predicted from a nucleation model for slow cooling rates. The formation of ferrite nuclei takes place with equilibrium composition on austenite grain boundaries. The nuclei are assumed to have a pill box shape in accordance with minimal interfacial energy. For higher cooling rates, early growth has to be taken into account to describe the transformation start. In contrast to nucleation, growth of the ferrite is characterized by paraequilibrium; i.e. only carbon can redistribute, whereas the diffusion of Mn is too slow to allow full equilibrium in the ternary system. However, Mn segregation to the moving ferrite-austenite interface has to be considered. The latter, in turn, exerts a solute drag effect on the boundary movement. Thus, growth kinetics is controlled by carbon diffusion in austenite modified by interfacial segregation of Mn. Employing a phenomenological segregation model, good agreement has been achieved with the measurements

Cerebral Epiphyseal Proteins and Melatonin Modulate the Hepatic and Renal Antioxidant Defense of Rats

The cerebral epiphysis (pineal gland) secrets melatonin and number of other proteins and peptides. It was thus hypothesized that antioxidant properties of epiphyseal proteins and melatonin could potentially benefit from exogenous therapies. In view of the therapeutic potential of these proteins, the present experiment was conducted to investigate the effect of buffalo epiphyseal proteins (BEP, at 100 μg/kg BW, i.p.) and melatonin (MEL, at 10 mg/kg BW, i.p) on changes in hepatic and renal antioxidant enzymes of adult female Wistar rats. Buffalo epiphyseal proteins significantly (P < .05) increased hepatic lipid peroxidation (LPO), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), reduced glutathione (GSH), and renal LPO, catalase (CAT), GR, GSH, GPx levels as compared to control animals. Similarly, MEL treatment significantly (P < .05) up-regulated hepatic SOD and GPx activity, whereas CAT, GR, GPx, and GSH levels in renal tissues were increased while SOD and LPO remained unaffected. Buffalo epiphyseal protein treatment produced greater effects on hepatic GPx and renal CAT and GSH levels than did MEL. These findings support the conclusion that buffalo epiphyseal proteins and melatonin activate a number of antioxidant mechanisms in hepatic and renal tissues

Effects of different Papua New Guinea sweetpotato varieties on performance and level of enteric pathogens in chickens

Published: 23 April 2019In the last decade, research has targeted the evaluation of local feed ingredients for use in monogastric diets to alleviate the high cost of production of livestock at smallholder levels in Papua New Guinea (PNG). The PNG smallholder poultry production system involves many families who rear multiple batches of meat birds every year. This study was conducted to evaluate the levels of enteric pathogens in the caeca of broilers fed with sweetpotato diets with varying levels of non-starch polysaccharides (NSP). Selection of a sweetpotato variety for use in broiler diets should be based on the total NSP content. In particular, varieties with low soluble NSPs are economical to use as Apparent Metabolizable Energy (AME) values are within the desired range for poultry and there is minimal need to include enzymes to improve NSP digestibility. The use of varieties with a low total NSP is also advantageous as the numbers of Clostridium perfringens was lower in broilers fed with these sweetpotato varieties. The level of Campylobacter and Salmonella levels were high in the ceca of birds fed with the sweetpotato varieties with high total NSP. These levels can be reduced with the inclusion of enzymes. This information will assist in the efficient use of local varieties of sweetpotato in PNG by small holder poultry farmers for sustainable poultry production and the commercial industry.Janet Pandi, Phil Glatz, Rebecca Forder and Kapil Chousalka

Immunomodulation by Melatonin: Its Significance for Seasonally Occurring Diseases

Melatonin is not only synthesized by the pineal gland but also in many other organs and tissues of the body, particularly by lymphoid organs such as the bone marrow, thymus and lymphocytes. Melatonin participates in various functions of the body, among which its immunomodulatory role has assumed considerable significance in recent years. Melatonin has been shown to be involved in the regulation of both cellular and humoral immunity. Melatonin not only stimulates the production of natural killer cells, monocytes and leukocytes, but also alters the balance of T helper (Th)-1 and Th-2 cells mainly towards Th-1 responses and increases the production of relevant cytokines such as interleukin (IL)-2, IL-6, IL-12 and interferon-gamma. The regulatory function of melatonin on immune mechanisms is seasonally dependent. This fact may in part account for the cyclic pattern of symptom expression shown by certain infectious diseases, which become more pronounced at particular times of the year. Moreover, melatonin-induced seasonal changes in immune function have also been implicated in the pathogenesis of seasonal affective disorder and rheumatoid arthritis. The clinical significance of the seasonally changing immunomodulatory role of melatonin is discussed in this review.Fil: Srinivasan, Venkataramanujam. University Sains Malaysia; MalasiaFil: Spence, D. Warren. No especifíca;Fil: Trakht, Ilya. No especifíca;Fil: Pandi Perumal, Seithikurippu R.. Columbia University; Estados UnidosFil: Cardinali, Daniel Pedro. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Cátedra de Fisiologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Maestroni, Georges J.. No especifíca

Melatonin, Immune Function and Aging

Aging is associated with a decline in immune function (immunosenescence), a situation known to correlate with increased incidence of cancer, infectious and degenerative diseases. Innate, cellular and humoral immunity all exhibit increased deterioration with age. A decrease in functional competence of individual natural killer (NK) cells is found with advancing age. Macrophages and granulocytes show functional decline in aging as evidenced by their diminished phagocytic activity and impairment of superoxide generation. There is also marked shift in cytokine profile as age advances, e.g., CD3+ and CD4+ cells decline in number whereas CD8+ cells increase in elderly individuals. A decline in organ specific antibodies occurs causing reduced humoral responsiveness. Circulating melatonin decreases with age and in recent years much interest has been focused on its immunomodulatory effect. Melatonin stimulates the production of progenitor cells for granulocytes-macrophages. It also stimulates the production of NK cells and CD4+ cells and inhibits CD8+ cells. The production and release of various cytokines from NK cells and T-helper lymphocytes also are enhanced by melatonin. Melatonin presumably regulates immune function by acting on the immune-opioid network, by affecting G protein-cAMP signal pathway and by regulating intracellular glutathione levels. Melatonin has the potential therapeutic value to enhance immune function in aged individuals and in patients in an immunocompromised state