Optimal Drug Regimen and Combined Drug Therapy and Its Efficacy in the Treatment of COVID-19: A Within-Host Modeling Study.

The COVID-19 pandemic has resulted in more than 524 million cases and 6 million deaths worldwide. Various drug interventions targeting multiple stages of COVID-19 pathogenesis can significantly reduce infection-related mortality. The current within-host mathematical modeling study addresses the optimal drug regimen and efficacy of combination therapies in the treatment of COVID-19. The drugs/interventions considered include Arbidol, Remdesivir, Interferon (INF) and Lopinavir/Ritonavir. It is concluded that these drugs, when administered singly or in combination, reduce the number of infected cells and viral load. Four scenarios dealing with the administration of a single drug, two drugs, three drugs and all four are discussed. In all these scenarios, the optimal drug regimen is proposed based on two methods. In the first method, these medical interventions are modeled as control interventions and a corresponding objective function and optimal control problem are formulated. In this framework, the optimal drug regimen is derived. Later, using the comparative effectiveness method, the optimal drug regimen is derived based on the basic reproduction number and viral load. The average number of infected cells and viral load decreased the most when all four drugs were used together. On the other hand, the average number of susceptible cells decreased the most when Arbidol was administered alone. The basic reproduction number and viral load decreased the most when all four interventions were used together, confirming the previously obtained finding of the optimal control problem. The results of this study can help physicians make decisions about the treatment of the life-threatening COVID-19 infection.

Optimal Control Studies on Age Structured Modeling of COVID-19 in Presence of Saturated Medical Treatment of Holling Type III.

COVID-19 pandemic has caused the most severe health problems to adults over 60 years of age, with particularly fatal consequences for those over 80. In this case, age-structured mathematical modeling could be useful to determine the spread of the disease and to develop a better control strategy for different age groups. In this study, we first propose an age-structured model considering two different age groups, the first group with population age below 30 years and the second with population age above 30 years, and discuss the stability of the equilibrium points and the sensitivity of the model parameters. In the second part of the study, we propose an optimal control problem to understand the age-specific role of treatment in controlling the spread of COVID -19 infection. From the stability analysis of the equilibrium points, it was found that the infection-free equilibrium point remains locally asymptotically stable when R 0 < 1 , and when R 0 is greater than one, the infected equilibrium point remains locally asymptotically stable. The results of the optimal control study show that infection decreases with the implementation of an optimal treatment strategy, and that a combined treatment strategy considering treatment for both age groups is effective in keeping cumulative infection low in severe epidemics. Cumulative infection was found to increase with increasing saturation in medical treatment.

Surface Plasmon-Coupled Dual Emission Platform for Ultrafast Oxygen Monitoring after SARS-CoV-2 Infection.

The outbreak of the COVID-19 pandemic has had a major impact on the health and well-being of people with its long-term effect on lung function and oxygen uptake. In this work, we present a unique approach to augment the phosphorescence signal from phosphorescent gold(III) complexes based on a surface plasmon-coupled emission platform and use it for designing a ratiometric sensor with high sensitivity and ultrafast response time for monitoring oxygen uptake in SARS-CoV-2-recovered patients. Two monocyclometalated Au(III) complexes, one having exclusively phosphorescence emission (λPL = 578 nm) and the other having dual emission, fluorescence (λPL = 417 nm) and phosphorescence (λPL = 579 nm), were studied using the surface plasmon-coupled dual emission (SPCDE) platform for the first time, which showed 27-fold and 17-fold enhancements, respectively. The latter complex having the dual emission was then used for the fabrication of a ratiometric sensor for studying the oxygen quenching of phosphorescence emission with the fluorescence emission acting as an internal standard. Low-cost poly (methyl methacrylate) (PMMA) and biodegradable wood were used to fabricate the microfluidic chips for oxygen monitoring. The sensor showed a high sensitivity with a limit of detection ∼ 0.1%. Furthermore, real-time oxygen sensing was carried out and the response time of the sensor was calculated to be ∼0.2 s. The sensor chip was used for monitoring the oxygen uptake in SARS-CoV-2-recovered study participants, to assess their lung function post the viral infection.

SNPs in the exons of Toll-like receptors are associated with susceptibility to type 1 diabetes in Chinese population.

OBJECTIVE: Toll-like receptors (TLRs) recognize a wide range of pathogen-associated molecular patterns (PAMP) and mount the initiation of immune response. Single nucleotide polymorphisms (SNPs) in exons of genes encoding TLRs might be responsible for the generation of an abnormal immune response which could lead to autoimmune diseases. In this study, we investigated the SNPs in TLRs in a Chinese population, and we hypothesized that SNPs in TLRs are associated with type 1 diabetes (T1D), an autoimmune disease caused by destruction of insulin producing pancreatic ß-cells, in the studied population. RESEARCH DESIGN AND METHODS: We selected 28 SNPs in exons of TLRs with an aim to identify those that might have a direct correlation with T1D etiology and many have not been included in previous GWAS studies. Genotyping of those SNPs in TLRs was performed in 429 T1D patients and 300 age and gender-matched healthy controls in Chinese Han population which was not included in the earlier GWAS studies. RESULTS: Among the SNPs genotyped, the T allele of TLR1-626 was positively associated with T1D (OR=1.98, Pc=0.01). We identified another T1D association locus in TLR6: the homozygous AA genotype of TLR6-1329 was negatively and heterozygous GA was positively associated with T1D (OR=0.54, Pc=0.02 and OR=1.70, Pc=0.03, respectively). We also identified the haplotype T-G-A in TLR1 gene to be positively associated with T1D (OR=2.22, Pc=0.03). Additional haplotypes in TLR-6 also showed significant positive and negative association. In addition, our haplotype analysis and conditional analysis showed that these two SNPs are the primary T1D associated loci among the SNPs tested in our cohort in each TLR gene. CONCLUSION: SNPs and haplotypes in TLR1 and TLR6 gene were associated with T1D in Chinese Han population. Our study, for the first time, indicates that TLR1 and TLR6 gene might play important roles in the etiology of T1D.

CRYAB-650 C>G (rs2234702) affects susceptibility to Type 1 diabetes and IAA-positivity in Swedish population.

BACKGROUND: Single nucleotide polymorphisms (SNPs) in the promoter region of CRYAB gene have been associated with in multiple sclerosis. CRYAB gene, which encodes alpha B-crystallin (a member of small heat shock protein), was reported as a potential autoimmune target. In this study we investigated whether SNPs in the promoter region of CRYAB gene were also important in the etiology of Type 1 diabetes (T1D). METHODS: Genotyping of SNPs in the promoter region of CRYAB gene was performed in a Swedish cohort containing 444 T1D patients and 350 healthy controls. Three SNPs were included in this study: CRYAB-652 A>G (rs762550), -650 C>G (rs2234702) and -249 C > G (rs14133). Two SNPs (CRYAB-652 and -650) were not included in previous genome wide association studies. RESULTS: CRYAB-650 (rs2234702)*C allele was significantly more frequent in patients than in controls (OR = 1.48, Pc = 0.03). CRYAB-650*C allele was associated with IAA positivity (OR = 8.17, Pc < 0.0001) and IA-2A positivity (OR = 2.14, Pc = 0.005) in T1D patients. This association with IAA was amplified by high-risk HLA carrier state (OR = 10.6, P < 0.0001). No association was found between CRYAB-650 and other autoantibody positivity (GADA and ICA). CRYAB haplotypes were also associated with IAA and IA-2A positivity (highest OR = 2.07 and 2.11, respectively), these associations remain in high HLA-risk T1D patients. CONCLUSIONS: CRYAB-650 was associated with T1D in the Swedish cohort we studied. CRYAB-650*C allele might confers susceptibility to the development of T1D. CRYAB-650 was also associated with the development of IAA-positivity in T1D patients, especially in those carrying T1D high-risk HLA haplotypes.

Killer cell immunoglobulin-like receptor along with HLA-C ligand genes are associated with type 1 diabetes in Chinese Han population.

OBJECTIVE: Killer cell immunoglobulin-like receptor (KIR) genes and their putative ligands human leukocyte antigen (HLA)-C genes have been associated with type 1 diabetes (T1D). We hypothesize that KIR genes and their ligands HLA-C genes are important in T1D aetiology. RESEARCH DESIGN AND METHODS: KIR and HLA-C ligand genotyping was performed in 259 T1D patients and 262 healthy children. RESULTS: No significant difference was observed in the distribution of KIR genes between T1D patients and healthy controls. However, frequency of HLA-C1 gene and HLA-C2 gene (marginal association) was higher in patient group. The combinations 2DL2-/HLA-C1+; 2DL3+/HLA-C1+; 2DS2-/HLAC1+ were positively associated with T1D. The combinations 2DL1+/HLA-C2-; 2DL2-/HLA-C1-; 2DL3+/HLA-C1-; 2DS2-/HLAC1- were found to be negatively associated with T1D. Among the genes we tested, a combination of HLA-C1 and -C2 conferred the strongest association with T1D and the strength of this association was higher than that of HLA-C1 alone. The frequencies of KIR 2DL1, 2DL2 and 2DL3 and HLA-C1 were higher in T1D patients positive for GAD65 autoantibody; frequency of KIR 2DS4 is higher in T1D patients positive for IA-2 autoantibody. The association between KIR/HLA-C gene and autoantibody status was not statistically significant after applying Bonferroni correction. CONCLUSION: In our study of a Han population (East China), we found no direct association of KIR genes with T1D. However, a combination of HLA-C1 and -C2 showed a positive association with T1D. Different combinations of HLA-C and KIR showed positive and negative association with T1D.

HLA class II alleles and haplotypes in Lithuanian children with type 1 diabetes and healthy children (HLA and type 1 diabetes).

OBJECTIVE: Type 1 diabetes mellitus is a slowly progressive autoimmune disease. The genetic background of type 1 diabetes mellitus is polygenic with the major disease locus located in the human leukocytes antigen (HLA) region. High risk and protective alleles, haplotypes, and genotypes have been determined in Lithuanian children with type 1 diabetes mellitus and healthy children. MATERIAL AND METHODS: In this case-control study, 124 children with diabetes (55 males and 69 females; mean age, 9.2±3.9 years) were tested for HLA class II and compared with 78 healthy controls (43 males and 35 females; mean age, 10.8±3.4 years; range, 0-15 years). HLA DRB1, DQA1, and DQB1 alleles were genotyped using a polymerase chain reaction. RESULTS: T1D risk-associated haplotypes (DR4)-DQA1*0301-DQB1*0302, (DR3)-DQA1*0501-DQB1*0201, and (DR1)-DQA1*0101-04-DQB1*0501 were more prevalent among children with diabetes than controls (50.0%, 41.1%, and 37.9% vs. 10.3%, 5.1%, and 24.4%, P<0.001). The haplotypes (DR4)-DQA1*0301-DQB1*0302 and (DR3)-DQA1*0501-DQB1*0201 increased T1D risk by 8.75 and 12.93 times, respectively (P<0.001). Protective haplotypes (DR2)-DQA1*0102-B1*0602, (DR11/12/13)-DQA1*05-DQB1*0301, and (DR13)-DQA1*0103-DQB1*0603 were significantly more prevalent among controls than children with diabetes (25.6%, 33.3%, 19.2% vs. 0%, 3.2%, 0%; P<0.001). These frequencies are quite similar to those from neighbor countries with varying incidence of type 1 diabetes mellitus. CONCLUSIONS: HLA class II haplotypes associated with type 1 diabetes mellitus positively or negatively were the same in Lithuanian children as in other European Caucasian populations. Differences in incidence and clinical manifestations of type 1 diabetes might be due to different environmental factors and/or lifestyle.

Prospective study of human papillomavirus (HPV) types, HPV persistence, and risk of squamous cell carcinoma of the cervix.

BACKGROUND: The link between squamous cell cervical carcinoma and human papillomavirus (HPV) 16/18 is well established, but the magnitude of the risk association is uncertain and the importance of other high-risk HPV (HRHPV) types is unclear. METHODS: In two prospective nested case-control series among women participating in cytologic screening in Sweden, we collected 2,772 cervical smears from 515 women with cancer in situ (CIS), 315 with invasive squamous cell carcinoma (SCC), and individually matched controls. All smears were tested for HPV with PCR assays, and the median follow-up until diagnosis was 5 to 7 years. Conditional logistic regression was used to estimate relative risks (RR) and 95% confidence intervals (95% CI). RESULTS: The presence of HPV16/18 in the first smear was associated with 8.5-fold (95% CI, 5.3-13.7) and 18.6-fold (95% CI, 9.0-38.9) increased risks of CIS and SCC, respectively, compared with women negative for HPV. Infection with other HRHPV types in the first smear was also associated with significantly increased risks for both CIS and SCC. Persistence of HPV16 infection conferred a RR of 18.5 (95% CI, 6.5-52.9) for CIS and 19.5 (95% CI, 4.7-81.7) for SCC. The HPV16/18 attributable risk proportion was estimated at 30% to 50% for CIS, and 41% to 47% for SCC. Other HRHPV types also conferred significant proportions. CONCLUSIONS: Our large population-based study provides quantification of risks for different HPV types and prospective evidence that non-16/18 HRHPV types increase the risk for future cervical cancer. IMPACT: This study gives further insights into cervical cancer risk stratification with implications for HPV-based prevention strategies.

Prospective study of human papillomavirus and risk of cervical adenocarcinoma.

Human papillomaviruses (HPV) are established as a major cause of cervical carcinoma. However, causality inference is dependent on prospective evidence showing that exposure predicts risk for future disease. Such evidence is available for squamous cell carcinoma, but not for cervical adenocarcinoma. We followed a population-based cohort of 994,120 women who participated in cytological screening in Sweden for a median of 6.7 years. Baseline smears from women who developed adenocarcinoma during follow-up (118 women with in situ disease and 164 with invasive disease) and their individually matched controls (1,434 smears) were analyzed for HPV using PCR. Conditional logistic regression was used to estimate odds ratios (OR) of future adenocarcinoma with 95% confidence intervals (CI). Being positive for HPV 16 in the first cytologically normal smear was associated with increased risks for both future adenocarcinoma in situ (OR: 11.0, 95% CI: 2.6-46.8) and invasive adenocarcinoma (OR: 16.0, 95% CI: 3.8-66.7), compared to being negative for HPV 16. Similarly, an HPV 18 positive smear was associated with increased risks for adenocarcinoma in situ (OR: 26.0, 95% CI: 3.5-192) and invasive adenocarcinoma (OR: 28.0, 95% CI: 3.8-206), compared to an HPV 18 negative smear. Being positive for HPV 16/18 in 2 subsequent smears was associated with an infinite risk of both in situ and invasive adenocarcinoma. In conclusion, infections with HPV 16 and 18 are detectable up to at least 14 years before diagnosis of cervical adenocarcinoma. Our data provide prospective evidence that the association of HPV 16/18 with cervical adenocarcinoma is strong and causal.

[Killer cell immunoglobin-like receptor and its ligand gene polymorphisms in Hunan Han patients with type 1 diabetes].

OBJECTIVE: To investigate the association of Killer cell immunoglobin-like receptor (KIR) gene and KIRs'ligand (HLA-C) gene polymorphisms with type 1 diabetes (T1DM). METHODS: Using polymerase chain reaction-sequence specific primer (PCR-SSP) to detect KIR and HLA-C genotype in 180 T1DM patients and 199 healthy controls from Hunan Han population. RESULTS: (1) The frequencies of KIR 2DL1 (98.9% vs 92.0%, OR = 7.78, P = 0.002), 3DL1 (94.3% vs 86.4%, OR = 2.67, P = 0.009) and 2DS4 (83.9% vs 70.9%, OR = 2.14, P = 0.003) were significantly higher in T1DM patients than those in the controls. (2) There were no differences in the frequencies of HLA-C1 and HLA-C2 between the patients and the controls, but the frequency of HLAC1+/C2+ (3.9% vs 9.6%, OR = 0.38, P = 0.03) was significantly lower in the T1DM patients. (3) The combination KIR2DL1-/HLA-C2-(0.6% vs 6.0%, OR = 0.087, P = 0.003) and KIR 2DS1-/HLA-C2-(53.3% vs 64.8%, OR = 0.62, P = 0.023) was significantly lower in the T1DM patients. CONCLUSION: The KIR gene polymorphism and KIR/HLA-C gene compatibility are associated with T1DM.

Prevention of beta-cell destruction in autoimmune diabetes: current approaches and future prospects.

Type 1 diabetes (T1D) is an autoimmune disease resulting from the destruction of pancreatic beta-cells. The main aim of treatment should be to prevent beta-cell destruction and preserve existing beta-cells in individuals with progressive autoimmunity. This can be achieved in several ways and in this chapter the authors have reviewed recent approaches that are currently being tested in animal models and human T1D patients under the following categories: i) antigen based therapy, ii) antibody-based therapy iii) other forms of therapy and iv) failed therapies.

Alternative routes of insulin delivery.

Parenteral route of insulin administration has been the mode of treatment for all Type 1 diabetics and Type 2 diabetics with complications. Patient compliance has really been a major concern for this route of administration. Several alternative routes of administration are under consideration for effective glycemic control, including oral, inhaled, buccal, nasal, and patch routes. One of the approaches involving inhaled insulin has now reached the market. Several other candidates may reach the market in the near future, the promising one being oral insulin.

Diabetes--role of epigenetics, genetics, and physiological factors.

Cells of organ systems are endowed with a relatively similar genome while epigenome niches keep varying chronologically and defined explicitly in the respective tissues. The genome of an individual is always influenced by parental, embryonic, tissue-specific, and environmental epigenomes and the same must have been the possible reason for invariable inquiries relating to familial, environmental and life style patterns in the preliminary investigations of diabetic complications. Unprecedented methylation of lysine residues of histones and cytosines of CpG islands of promoter DNA impede the transcription of genes and homocysteine is the metabolic key player of methyl groups. Gck and COX7A1 are the 2 examples in the present review to elucidate the epigenetic influence on the onset of diabetes. miRNAs are additional promising cellular components influencing both at transcriptional and translational levels and promoting either in favour or against (i.e., feed back) TFs, signaling factors and proteins through their pliotropic effects and thus are reported to regulate cellular physiology. miR-124a and miR-9 are primarily endemic to nervous tissue and they are now being exploited in islets for their function in executing exocytosis of insulin, which of course is one of the fundamental canons of diabetes. miR-375 persuades beta cells for glucose-induced insulin gene expression. The current approach to evaluate the constellation of genes and their products involved in diabetes in huge number of samples through GWA studies may unravel intricacies involved in the management of diabetes and its associated consequences.

Risk conferred by HLA-DR and DQ for type 1 diabetes in 0-35-year age group in Sweden.

UNLABELLED: HLA DR4-DQ8 and DR3-DQ2 haplotypes account for 89% of newly diagnosed cases of type 1 diabetes (T1D) in Sweden. The presence of a single copy of DQ6 confers protection. The aim of the present study is to evaluate whether the risk conferred by high risk HLA DR and DQ to T1D is similar in all regions of Sweden and see whether there are any significant regional differences. The subjects comprised 799 consecutively diagnosed T1D patients and 585 age-, sex-, and geography-matched healthy controls in the age group 0-35 years. HLA typing for high-risk haplotypes was previously performed using PCR-SSOP and RFLP. The results showed that HLA DR3-DR4 gave an odds ratio of 8.14 for the whole of Sweden. However, when the study group was divided into six geographical regions, subjects from Stockholm had the highest OR, followed by those from Lund, Linköping, Gothenburg, Umeå, and Uppsala. Absolute protection was conferred by the presence of DQ6 in subjects from the Linköping region, but varied in the other regions. The frequency of DR3 and DQ2, DR4 and DQ8, DR15, and DQ6 in patients showed high linkage for each region, but were different between regions. IN CONCLUSION: The risk conferred by high-risk HLA varies in different regions for a homogenous population in Sweden. The results highlight the important role played by the various environmental factors in the precipitation of T1D.

Variations in incidence of type 1 diabetes in different municipalities of stockholm.

This article reports a test of the hypothesis that municipalities within the County of Stockholm have varying incidence rates of type 1 diabetes (T1D), suggesting a strong etiologic environmental component to the disease. The study group included T1D patients in the age group from birth to 18 years who were diagnosed each year from 20 municipalities in Stockholm County during the 1990-2003. Specific incidence rates by age, sex, and socioeconomic characteristics (income level, proportion of taxpayers, proportion of foreigners, population density and green cover) were estimated annually together with age standardization. chi(2) analyses were used for the statistical assessment of variability in incidence. During the study period, 733 newly diagnosed T1D patients aged 0-18 years were recorded from the 20 municipalities under study. The overall age-standardized incidence in these 20 municipalities was 24.38 (22.65-26.21) per 100,000, with 45.35 (32.08-62.29) as highest and 13.41 (9.53-18.35) as lowest estimated incidence. For all socioeconomic variables statistically significant heterogeneity was demonstrated in the standardized incidence rate. High green index was positively associated with the incidence of T1D, as was low population density. For the three remaining socioeconomic variables no clear patterns of associations with incidence of T1D were seen. This study demonstrates a considerable and statistically significant variation between the lowest and highest values in the incidence and prevalence rates for T1D in municipalities of Stockholm County. Such variation seems unlikely to be explained by genetic differences since the population is homogeneous. Our study provides support for the hypothesis that environmental factors have a major influence on the pathogenesis of T1D.

Type 1 diabetes versus type 2 diabetes with onset in persons younger than 20 years of age.

Type 1 diabetes (T1D) is the most common form of diabetes in children in Western countries. There have been no large studies of childhood diabetes from India. We undertook the MEDI study (Multicenter Survey of Early Onset Diabetes in India) to assess the proportion of various subtypes of diabetes among the young subjects presenting to the endocrinology divisions of seven large teaching hospitals in different regions of India. In addition, we compared the clinical features of T1D and type 2 diabetes (T2D) in Indian subjects. Patients with onset of disease at younger than 20 years of age were included in this study. Six hundred and three subjects (603) were studied of whom 535 subjects (89%) had T1D, 36 (6%) had T2D, 18 (3%) had diabetes related to tropical pancreatitis or other forms of chronic pancreatitis, while other subtypes accounted for the rest. Compared to those with T2D, subjects with T1D were younger, had a lower C-peptide level, higher prevalence of ketosis, lower prevalence of acanthosis nigricans, and lower LDL and triglyceride levels. When compared with that of T2D, a higher proportion of patients with T1D were positive for GAD-65 and IA-2 antibodies, and this difference was statistically significant for GAD-65 antibodies. Overall, this large multicenter study showed that T1D is the commonest form of diabetes in childhood. T2D is the next most common kind, while chronic pancreatitis-related diabetes is uncommon.

MICA marks additional risk factors for Type 1 diabetes on extended HLA haplotypes: an association and meta-analysis.

The association of the HLA complex on chromosome 6 does not explain total linkage of the HLA region to Type 1 Diabetes (T1D), leading to the hypothesis that there may be additional causal genes in the HLA region for immune-related disorders. Reports on the MHC Class I chain-related A (MICA) gene as candidate for association with T1D are contradicting. We investigated whether variation in MICA is associated to T1D in a cohort of 350 unrelated individuals with juvenile-onset T1D and 540 control subjects, followed by a meta-analysis of 14 studies. We also investigated an HLA-independent association for MICA with T1D. In our case-control study, we found that the MICA*A5 variant was significantly associated with an increased risk for T1D, while MICA*A6 was significantly associated with a decreased risk that was confirmed by our meta-analysis. However, the meta-analysis did not show an association of MICA*A5 T1D. Analysis of MICA alleles conditional on T1D-associated high-risk MHC class II haplotypes revealed that MICA*A6 was associated with an increased risk for T1D when this marker co-occurred with HLA DQ2DR17 T1D-risk-haplotypes. In contrast, MICA*A6 reduced the risk from the HLA DQ8DR4 T1D-risk haplotype. Moreover, MICA*A9 showed a significant association to increased risk for T1D on DQ8DR4 haplotypes. Co-inheritance of MICA*A6 with the HLA DQ2DR17 haplotype in T1D indicates this haplotype may carry the additional genetic factors for T1D, but our study does not support an independent association between MICA variants and T1D.

Omega-3 fatty acids for nutrition and medicine: considering microalgae oil as a vegetarian source of EPA and DHA.

Long-chain EPA/DHA omega-3 fatty acid supplementation can be co-preventative and co-therapeutic. Current research suggests increasing accumulated long chain omega-3s for health benefits and as natural medicine in several major diseases. But many believe plant omega-3 sources are nutritionally and therapeutically equivalent to the EPA/DHA omega-3 in fish oil. Although healthy, precursor ALA bio-conversion to EPA is inefficient and production of DHA is nearly absent, limiting the protective value of ALA supplementation from flax-oil, for example. Along with pollutants certain fish acquire high levels of EPA/DHA as predatory species. However, the origin of EPA/DHA in aquatic ecosystems is algae. Certain microalgae produce high levels of EPA or DHA. Now, organically produced DHA-rich microalgae oil is available. Clinical trials with DHA-rich oil indicate comparable efficacies to fish oil for protection from cardiovascular risk factors by lowering plasma triglycerides and oxidative stress. This review discusses 1) omega-3 fatty acids in nutrition and medicine; 2) omega-3s in physiology and gene regulation; 3) possible protective mechanisms of EPA/DHA in major diseases such as coronary heart disease, atherosclerosis, cancer and type 2 diabetes; 4) EPA and DHA requirements considering fish oil safety; and 5) microalgae EPA and DHA-rich oils and recent clinical results.