Alzheimer's Disease: A Suitable Case for Treatment with Precision Medicine?

Alzheimer's disease (AD) is the most common cause of neurodegenerative impairment in elderly people. Clinical characteristics include short-term memory loss, confusion, hallucination, agitation, and behavioural disturbance. Owing to evolving research in biomarkers AD can be discovered at early onset, but the disease is currently considered a continuum, which suggests that pharmacotherapy is most efficacious in the preclinical phase, possibly 15 - 20 years before discernible onset. Present developments in AD therapy aim to respond to this understanding and go beyond the drug families that relieve clinical symptoms. Another important factor in this development is the emergence of precision medicine that aims to tailor treatment to specific patients or patient subgroups. This relatively new platform would categorize AD patients on the basis of parameters like clinical aspects, brain imaging, genetic profiling, clinical genetics and epidemiological factors. This review enlarges on recent progress in the design and clinical use of antisense molecules, antibodies, antioxidants, small molecules and gene editing to stop AD progress and possibly reverse the disease on the basis of relevant biomarkers.

Parkinson's Disease: A Tale of Many Players.

In 2020, more than 9 million patients suffering from Parkinson's disease (PD) were reported worldwide, and studies predict that the burden of this disease will grow substantially in industrial countries. In the last decade, there has been a better understanding of this neurodegenerative disorder, clinically characterized by motor disturbances, impaired balance, coordination, memory difficulties, and behavioral changes. Various preclinical investigations and studies on human postmortem brains suggest that local oxidative stress and inflammation promote misfolding and aggregation of alpha-synuclein within Lewy bodies and cause nerve cell damage. Parallel to these investigations, the familial contribution to the disease became evident from studies on genome-wide association in which specific genetic defects were linked to neuritic alpha-synuclein pathology. As for treatment, currently available pharmacological and surgical interventions may improve the quality of life but do not stop the progress of neurodegeneration. However, numerous preclinical studies have provided insights into the pathogenesis of PD. Their results provide a solid base for clinical trials and further developments. In this review, we discuss the pathogenesis, the prospects, and challenges of synolytic therapy, CRISPR, gene editing, and gene- and cell-based therapy. We also throw light on the recent observation that targeted physiotherapy may help improve the gait and other motor impairments.

Friends and Foes in Alzheimer's Disease.

Alzheimer's disease (AD) is a disabling neurodegenerative disease. The prognosis is poor, and currently there are no proven effective therapies. Most likely, the etiology is related to cerebral inflammatory processes that cause neuronal damage, resulting in dysfunction and apoptosis of nerve cells. Pathogens that evoke a neuroinflammatory response, collectively activate astrocytes and microglia, which contributes to the secretion of pro-inflammatory cytokines. This leads to the deposit of clustered fragments of beta-amyloid and misfolded tau proteins which do not elicit an adequate immune reaction. Apart from the function of astrocytes and microglia, molecular entities such as TREM2, SYK, C22, and C33 play a role in the physiopathology of AD. Furthermore, bacteria and viruses may trigger an overactive inflammatory response in the brain. Pathogens like Helicobacter pylori, Chlamydia pneumonia, and Porphyromonas gingivalis (known for low-grade infection in the oral cavity) can release gingipains, which are enzymes that can damage and destroy neurons. Chronic infection with Borrelia burgdorferi (the causative agent of Lyme disease) can co-localize with tau tangles and amyloid deposits. As for viral infections, herpes simplex virus 1, cytomegalovirus, and Epstein-Barr virus can play a role in the pathogenesis of AD. Present investigations have resulted in the development of antibodies that can clear the brain of beta-amyloid plaques. Trials with humanized aducanumab, lecanemab, and donanemab revealed limited success in AD patients. However, AD should be considered as a continuum in which the initial preclinical phase may take 10 or even 20 years. It is generally thought that this phase offers a window for efficacious treatment. Therefore, research is also focused on the identification of biomarkers for early AD detection. In this respect, the plasma measurement of neurofilament light chain in patients treated with hydromethylthionine mesylate may well open a new way to prevent the formation of tau tangles and represents the first treatment for AD at its roots.

Ten Famous Composers of the Romantic Era and Their Causes of Death.

The musical composers in the Romantic Era (1800-1910) strived for compositions that expressed human life, including happiness, harmony, and despair. They lived in a period in which freedom of thought, expression of emotion, and inspiration by nature predominated. During this period, intensive trading with other parts of the world brought new microorganisms along, which made infections and epidemics very common. This article serves to address the cause of death and relevant biographic data of a number of well-known Romantic composers. Primarily, this review refers to clinically significant findings using reports that were retrieved from PubMed, Embase, and Google over the 19th, 20th, and 21st centuries till 14th June 2021. This text dwells on diseases and the cause of death of ten composers, namely Mozart, Beethoven, Chopin, Schubert, Schumann, Mendelssohn, Brahms, Liszt, Mahler, and Bruckner. It is evident that from the perspective of modern medicine, symptoms and forensic facts are not complete, but witnesses' reports and recent medical research have provided passable and plausible clarity. Although many questions will remain unanswered, it appears that the diseases of these composers and their causes of death have their origins in alcohol abuses, age, epidemics (like tuberculosis), and syphilis.

PARP Inhibition and Beyond in BRCA-Associated Breast Cancer in Women: A State-Of-The-Art Summary of Preclinical Research on Risk Reduction and Clinical Benefits.

In mammalian cells, DNA damage response initiates repair by error-free homologous recombination (HRR) or by error-prone non-homologous end joining (NHEJ). DNA damage is detected by PARP proteins that facilitate this repair, both in normal cells and in cancer cells. Cells containing BRCA1/2 mutations have an HRR-deficient repair mechanism which may result in unrepaired one-ended double-strand breaks and stalled replication forks, considered as the most lethal cell damage. Here, we review the state of the art of the role of Poly (ADP-ribose) polymerase (PARP) inhibitors as a precision-targeted anticancer drug in BRCA1/2-mutated female breast cancer. Although knowledge is incomplete, it is assumed that the main role of the archetype PARP1 in the cell nucleus is to detect and adhere to single-strand breaks. This mediates possible damage repair, after which cells may continue replication; this process is called synthetic lethality. As for PARP clinical monotherapy, progression-free survival has been observed using the FDA- and EMA-approved drugs olaparib and talazoparib. In the case of combined drug therapy, a synergy has been demonstrated between veliparib and platinum drugs. Information regarding adverse effects is limited, but hematological effects have been described. However, there is need for multicenter trials, preferably conducted without commercial guidance and funding. Some of the available trials reported resistance to PARP inhibitors. In this review, we also describe the various causes of resistance to PARP inhibitors and research indicating how resistance can be overcome.

Coffee Consumption and Cancer Risk: An Assessment of the Health Implications Based on Recent Knowledge.

A significant number of studies suggest that coffee consumption reduces cancer risk. This beneficial effect is usually ascribed to the presence of polyphenolic antioxidants and anti-inflammatory agents, including caffeine, cafestol, kahweol, and chlorogenic acids. To summarize recent literature on this subject, we performed a bibliographic search in PubMed and Embase over the period January 2005 to December 2020 to identify cohort studies and meta-analysis (with data collection ensuring quality of selected reports) that could provide quantitative data on the relationship between coffee consumption and common cancers. The totality of eligible scientific articles supports the evidence that coffee intake is inversely associated with risk of hepatocellular cancer and, to a slight extent, risk of breast cancer among postmenopausal women. As to the association with other organs, including the esophagus, pancreas, colorectum, kidneys, bladder, ovaries, and prostate, the results are less clear as reports reveal conflicting results or statistically nonsignificant data. Therefore, this overview does not provide broad-based conclusions. Important uncertainties include general study design, inhomogeneous patient sampling, different statistical analysis (deliberate), misreporting of socioeconomic status, education, coffee-brewing methods, consumption of caffeinated or decaffeinated coffee, smoking habits, and alcohol intake. Clearly, more epidemiologic research needs to be conducted before solid science-based recommendations can be made with regard to coffee consumption.

Breast Cancer Induced by X-Ray Mammography Screening? A Review Based on Recent Understanding of Low-Dose Radiobiology.

Screening mammography offers the possibility of discovering malignant diseases at an early stage, which is consequently treated early, thereby reducing the mortality rate. However, ionizing radiation as used in low-dose X-ray mammography may be associated with a risk of radiation-induced carcinogenesis. In the context of the harmful effects of ionizing radiation, this article reviewed novel radiobiological data and provided a simulation of the relative incidence of radiation-induced breast cancer due to screening against a background baseline incidence in a population of 100,000 individuals. The use of modern digital mammographic technology was assumed, giving rise to a glandular dose of 2.5 mGy from a 2-view per breast image. Assuming no latency time, this led to a ratio of induced incidence rate over baseline incidence rate of about 1.6‰ for biennial screening in women aged 50-74 years, although it cannot be excluded that the dose and dose rate effectiveness factor values relying on new radiobiological insights may lower this number to about 0.7‰. This carcinogenic risk is considered small in relation to the potential beneficial effects of screening, especially as latency time was not taken into consideration. However, individuals who are known to be carriers of risk-increasing genetic variations and/or have an inherited disposition of breast cancer should avoid ionizing radiation as much as possible and should be referred to ultrasound or magnetic resonance imaging. In addition, a significant, but difficult to quantify, risk of cancer is present for individuals who suffer from hypersusceptibility to ionizing radiation.

Mozart, music and medicine.

According to the first publication in 1993 by Rauscher et al. [Nature 1993;365:611], the Mozart effect implies the enhancement of reasoning skills solving spatial problems in normal subjects after listening to Mozart's piano sonata K 448. A further evaluation of this effect has raised the question whether there is a link between music-generated emotions and a higher level of cognitive abilities by mere listening. Positron emission tomography and functional magnetic resonance imaging have revealed that listening to pleasurable music activates cortical and subcortical cerebral areas where emotions are processed. These neurobiological effects of music suggest that auditory stimulation evokes emotions linked to heightened arousal and result in temporarily enhanced performance in many cognitive domains. Music therapy applies this arousal in a clinical setting as it may offer benefits to patients by diverting their attention from unpleasant experiences and future interventions. It has been applied in the context of various important clinical conditions such as cardiovascular disorders, cancer pain, epilepsy, depression and dementia. Furthermore, music may modulate the immune response, among other things, evidenced by increasing the activity of natural killer cells, lymphocytes and interferon-γ, which is an interesting feature as many diseases are related to a misbalanced immune system. Many of these clinical studies, however, suffer from methodological inadequacies. Nevertheless, at present, there is moderate but not altogether convincing evidence that listening to known and liked music helps to decrease the burden of a disease and enhances the immune system by modifying stress.

[¹8F]fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography imaging in oncology: initial staging and evaluation of cancer therapy.

Positron emission tomography (PET) with [¹8F]fluoro-2-deoxy-D-glucose (FDG) has proven to be a valuable diagnostic modality in various diseases. Its accuracy has been improved with the hybrid PET/computed tomography (CT) technique because of precise anatomic location of areas of abnormal FDG accumulation. This integrated PET/CT modality has been widely adopted, particularly in oncology. This paper reviews the role of FDG-PET/CT imaging in breast cancer, non-small-cell lung cancer, colorectal cancer, head and neck cancer as well as lymphoma on the basis of recent key articles. Special attention is paid to preoperative diagnostic workup, evaluation of treatment response and survival prognosis. Experience from specialized centers indicates that there is strong evidence for the clinical effectiveness of FDG-PET/CT in staging, restaging and the prediction of response to therapy in the above-mentioned malignancies. It is concluded that this imaging modality contributes considerably to improved patient management and paves the way to personalize cancer treatment in a cost-effective way.

Radiation dose features and solid cancer induction in pediatric computed tomography.

Over the past two decades technical advances and improvements have made computed tomography (CT) a valuable and essential tool in the array of diagnostic imaging modalities. CT uses ionizing radiation (X-rays) which may damage DNA and increase the risk of carcinogenesis. This is especially pertinent in pediatric CT as children are more radiosensitive and have a longer life expectancy than adults. The purpose of this paper is to review and elucidate the potential harmful effects of ionizing radiation in terms of solid cancer induction from pediatric CT scanning. In the light of scientific and technical developments, we will also discuss the possible strategies and ongoing efforts to reduce CT radiation exposure in pediatric patients. In this context, we will not ignore the fact that a well-justified CT scan may exceed its risk and have a favorable impact.

Cancer induction caused by radiation due to computed tomography: a critical note.

The considerable rise of computed tomography (CT) procedures over the past few decades has urged responsible authorities and researchers to evaluate the risk of carcinogenesis in the population in relation to the radiation dose delivered to the patient. A single patient undergoing CT may receive a radiation equivalent dose that varies between about 2 mSv (head ) to about 20 mSv (CT-based coronary angiography). Whereas the latter represents a substantial dose delivered to one patient it is, however, population-wise far below the area of the so-called low doses, i.e. 50 mSv in children and 100 mSv in adults. While at effective doses above 50 mSv the risk of cancer induction increases linearly with dose, this dose-response relation has not been demonstrated at doses below 50 mSv. Below 50 mSv no convincing epidemiological evidence for cancer risk exists. Calculations on this risk are based on scientifically questionable, if not invalid, extrapolations of data from higher doses. However, the failure to demonstrate that a risk of cancer exists does not mean that there is no risk. This paper summarizes the data mentioned in various articles from recent literature discussing cancer risks due to CT and puts the results of these studies in perspective of current scientific knowledge in the field of radiation protection. For this we follow the lead of the ICRP and UNSCEAR. Furthermore, we review the strategies and efforts of various national and international bodies and manufacturers of CT apparatus to lower the radiation dose to the patient.

The protective effect of the Mediterranean diet: focus on cancer and cardiovascular risk.

The lower occurrence of cancer and cardiovascular disease in the population around the Mediterranean basin has been linked to the dietary habits of the region. Indeed, this so-called Mediterranean diet is essentially different from the diets consumed in Western and Northern European countries and is rich in nuts, fruits, vegetables, legumes, whole-wheat bread, fish, and olive oil, with moderate amounts of red wine, which is mainly consumed during meals. Although a variety of cultural and religious traditions exist among the peoples of the Mediterranean area, olive oil, fish, and red wine hold a traditional and central position in the culinary routines of the region. The components of the diet contain an ample source of molecules with antioxidant and anti-inflammatory actions, among which omega-3 fatty acids, oleic acid, and phenolic compounds hold a prominent place. This review will summarize the results of important epidemiological studies that have investigated the protective effect of fish and olive oil on the risk of breast, prostate, and colorectal cancer and of wine on the risk of cardiovascular disease. The present review also aims to elucidate the various mechanisms by which various dietary components exhibit their beneficial action. In this respect, emphasis will be placed on the properties of omega-3 fatty acids from fish, oleic acid from olive oil, and phenolic compounds from olive oil and red wine.

Biomarkers for Alzheimer's disease.

It has been determined that patients suffering from mild cognitive impairment (MCI) may progress to Alzheimer's disease (AD), which offers a window for therapeutic intervention to slow or halt disease progression. Thus, the detection of prodromal AD is essential to initiate early treatment. The key pathologic hallmark of AD is amyloid beta peptide 42 (Abeta(42)). Probably because of its direct contact with brain tissue, levels of Abeta(42) in combination with phosphorylated tau determined in cerebrospinal fluid (CSF) appear to be useful markers of the disease. In addition, structural and functional brain imaging with magnetic resonance techniques and metabolic imaging with positron emission tomography have been shown to provide useful disease markers. These imaging markers include diminished global brain and hippocampus volume, grey matter loss in the mediotemporal lobe, functional neuronal disconnections and regional hypometabolism. To date, the combination of CSF Abeta(42) and tau parameters provide a sensitivity and a specificity of > 80%. In this article we summarize key aspects of diagnostic markers for AD based on published knowledge. We also dwell on the potential usefulness of these markers for treatment monitoring and in the process of developing and evaluating novel drugs.

Fatty acid facts, Part IV: docosahexaenoic acid and Alzheimer's disease. A story of mice, men and fish.

The primary pathological hallmark of Alzheimer's disease (AD) is neurodegeneration by neuronal cell death caused by the development of aggregates of beta- amyloid peptide. Epidemiologically, low fish intake and low blood levels of the omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) have been related to an increased risk of AD. Test animals on dietary DHA depletion show learning and memory deficits, whereas their brains show inflammatory and oxidative damage to neurons and synaptic defects. The behavioral defects could be reversed by DHA supplementation exemplified by improved cognitive function. Mechanistically, these phenomena have been explained by the antiinflammatory action of DHA. This immunomodulation has been ascribed to incorporation of increased amounts of DHA in cell membrane phospholipids, leading to decreased production of proinflammatory omega-6 eicosanoids. The latter molecules may cause vascular damage which promotes the clinical signs of AD. This review will provide an overview on the available knowledge with regard to the role of DHA in AD with a focus on mechanistic and epidemiological investigations.

Radionuclide evaluation of the lower gastrointestinal tract.

This review outlines the technical aspects and diagnostic performance parameters of nuclear medicine procedures used on patients with disorders of the lower gastrointestinal tract, with the exclusion of techniques using tumor-seeking radiopharmaceuticals. Chronic disorders of the lower gastrointestinal tract often reduce the quality of life because of discomfort from constipation or diarrhea. Five classes of radionuclide procedures are used to characterize these disorders: transit scintigraphy, searches for ectopic gastric mucosa in Meckel's diverticulum, scintigraphy of active inflammatory bowel disease, scintigraphic defecography, and scintigraphy to detect sites of gastrointestinal bleeding. Protocols for these procedures and their relative merit in patient management are discussed, with special emphasis on their potential for semiquantitative assessment of the pathophysiologic parameter investigated. Quantitation is particularly relevant for prognostic purposes and for monitoring the efficacy of therapy.

Fatty acid facts, part II: role in the prevention of carcinogenesis, or, more fish on the dish?

Many laboratory studies suggest that n-3 fatty acids, especially the long-chain polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have antitumor effects. The mechanisms involved in their anticarcinogenic action include the suppression of the biosynthesis of proinflammatory molecules, the influence on transcription factor activity and gene expression, the influence on signal transduction, the alteration of hormone-stimulated cell growth and the suppression of the production of free radicals and reactive oxygen species. In general, n-6 fatty acids and their derivatives promote the production of proinflammatory eicosanoids, whereas n-3 fatty acids suppress this action. The encouraging preclinical results are only scarcely confirmed in reviews and meta-analysis of epidemiological data roughly published before 2005. However, around 2005, the first reports on epidemiological studies based on the assessment of the concentration of EPA and DHA in the erythrocyte cell membrane in individual study participants started to appear. Without exception, these publications demonstrate that higher EPA (and possibly DHA) concentrations in the cell membrane, a validated measure for plasma fatty acids, is associated with lower cancer risk. These intriguing results are confirmed by the recently published huge European Prospective Investigation into cancer and nutrition (N = 478,040 men and women) and U.S.-based Physicians Health Study (N = 22,071 men). These studies have unequivocally confirmed that fish intake has a favorable effect on cancer risk . This review aims to elucidate the various mechanisms by which n-3 fatty acids may affect the process of carcinogenesis. For this summary of knowledge, we focus on the effects of n-3 intake on the risk of breast cancer, prostate cancer and colorectal cancer.

Fatty acid facts, Part III: Cardiovascular disease, or, a fish diet is not fishy.

Preclinical and clinical studies have demonstrated that omega-3 polyunsaturated fatty acids (n-3 PUFAs) play a significant role in the prevention of cardiovascular disease. These fatty acids are called essential fatty acids as they fulfil essential functions and the mammalian cell cannot synthesize them de novo. Dietary sources of n-3 PUFAs include fish oils rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The clinical relevance of these molecules is derived from the incorporation of EPA and DHA into cell membranes. The presence of EPA/DHA alters the physical characteristics of the membrane. Both these altered physicochemical membrane properties and the presence of n-3 PUFAs released by the action of phospholipid lipases (resulting in antiinflammatory eicosanoids) improve biological functions such as signal transduction, ion channelling and ligand binding to nuclear receptors. EPA/DHA also reduce or quench gene expression of cyclooxygenase-2 and other enzymes, thereby diminishing the formation of proinflammatory molecules. Increased EPA/DHA concentration also gives rise to antiinflammatory lipid mediators, called lipoxins, resolvins and protectins. Another important function of n-3 PUFAs is scavenging of free radicals, which diminishes inflammatory response and oxidation of lipoprotein particles, notably low density lipoproteins. The interplay of these molecular processes has distinct cardioprotective effects, which involve actions on lipid metabolism, lipoprotein particle size, blood pressure, vascular function, coagulation potential, inflammatory response, atheroma formation and antiarrhythmic. In view of these actions, fish oil preparations and/or intake of oily fish are recommended as primary and secondary prevention of cardiovascular disease and sudden cardiac death. Large, ongoing trials will further elucidate the presumed favorable effects of EPA/DHA in heart failure and diabetes. This review provides a summary of the physiological mechanisms of the action of EPA and DHA and highlights the epidemiological evidence for a reduction in cardiac events and mortality.

Towards the use of nanoparticles in cancer therapy and imaging.

Nanosystems have unique physical and biological properties. Various systems have been designed for medical use and offer promising ways of delivering drugs at high concentrations at sites of interest, e.g., cancer lesions, while reducing systemic side effects. Nanotechnology has also opened ways for the development of contrast agents and radiopharmaceuticals for specific targeting, which is presently changing research strategies in the field of magnetic resonance imaging, ultrasound imaging and nuclear medicine applications. This article aims to overview how "nanomedicine" is presently influencing drug design for diagnostic and therapeutic purposes.

Radioimmunotherapy of non-Hodgkin's lymphoma: molecular targeting and novel agents.

In recent years monoclonal antibodies have played an important role in cancer therapy. This successful track is grosso modo based upon developments in the production of desired antibody molecules, the identification of suitable tumor antigens and the construction of chimeric and fully humanized antibodies. Especially in hematologic disorders, notably in non-Hodgkin's disease, the monoclonal antibody rituximab has proven to be of value in relapsed or refractory disease. Yet, to overcome the nonoptimal properties of this drug, especially in relation to the time to next therapy, radiolabeled immunoconjugates have been synthesized. For this purpose, the radionuclide yttrium-90 has been linked to the monoclonal antibody ibritumomab via the chelator tiuxetan. The most recent clinical results of this radiolabeled agent versus the nonradioactive drug treatment are reviewed in this paper. Furthermore, attention is paid to the monoclonal antibody tositumomab labeled with iodine-131, of which the first clinical results have become available most recently. This overview also mentions possibilities to increase the therapeutic efficacy of radionuclide immunoconjugates. This can be achieved by enhancing the targeting characteristics of the antibody and the use of alpha radiation-emitting radionuclides.