Jan Homolak

Jan Homolak
University of Zagreb · Department of Pharmacology

MD

About

129
Publications
66,744
Reads
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447
Citations
Citations since 2017
113 Research Items
447 Citations
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2017201820192020202120222023050100150
2017201820192020202120222023050100150
Additional affiliations
September 2017 - September 2017
University of Wuerzburg
Position
  • Research Assistant
August 2016 - September 2016
University of Wuerzburg
Position
  • Research Assistant
August 2015 - present
University of Zagreb, School of Medicine
Position
  • Student Research Assistant

Publications

Publications (129)
Article
Full-text available
The gastrointestinal system may be involved in the etiopathogenesis of the insulin-resistant brain state (IRBS) and Alzheimer’s disease (AD). Gastrointestinal hormone glucagon-like peptide-1 (GLP-1) is being explored as a potential therapy as activation of brain GLP-1 receptors (GLP-1R) exerts neuroprotection and controls peripheral metabolism. Int...
Article
Scope: Galactose, a ubiquitous monosaccharide with incompletely understood physiology is often exploited for inducing oxidative-stress mediated aging in animals. Recent research demonstrates that galactose can conserve cellular function during periods of starvation and prevent/alleviate cognitive deficits in a rat model of sporadic Alzheimer’s dise...
Article
Introduction: Gastrointestinal dyshomeostasis is investigated in the context of metabolic dysfunction, systemic and neuro-inflammation in Alzheimer's disease. Dysfunctional gastrointestinal redox homeostasis and brain-gut incretin axis have been reported in the rat model of insulin-resistant brain state-driven neurodegeneration induced by intracere...
Preprint
Full-text available
Ramnot et al. recently described a fascinating case of a complete regrowth of hair following scalp tattooing in a patient with alopecia universalis unresponsive to previous treatment (local and systemic glucocorticoids, squaric acid dibutyl ester immunotherapy) despite high compliance1. The causality between scalp tattooing and alopecia regression...
Preprint
Full-text available
Dear Editor, I read with great interest a recent article published in Chemical Research in Toxicology by Karadagli et al. entitled „Are Some Metals in Tattoo Inks Harmful to Health? An Analytical Approach“1. Karadagli et al. measured the relative contribution of metals to the composition of 3 commercially available tattoo inks (red, green, and bla...
Preprint
Full-text available
Dear Editor, We read with great interest a recent study by Zhu et al. which suggests that repeated parenteral administration of D-galactose (750 mg/kg/day) exerts protective effects against ionizing radiation-induced injury in mice possibly by modulating gut microbiota [1]. This letter intends to supplement the aforementioned article by proposing a...
Preprint
Cognitive deficit is a frequent non-motor symptom in Parkinson 's disease (PD) with an unclear pathogenesis. Recent research indicates possible involvement of insulin resistance and glutamate excitotoxicity in PD development. We investigated cognitive performance and the brain glutamate and insulin signaling in a rat model of PD induced by bilatera...
Article
Full-text available
Impaired response to insulin has been linked to many neurodegenerative disorders like Alzheimer’s disease (AD). Animal model of sporadic AD has been developed by intracerebroventricular (icv) administration of streptozotocin (STZ), which given peripherally causes insulin resistance. Difficulty in demonstrating insulin resistance in this model led t...
Preprint
Full-text available
Dear Editors, I read with great interest a recent study by Robinette et al. in which the authors use cross-sectional baseline visit data from the Micronutrients for ADHD in Youth (MADDY; NCT03252522) cohort to assess the association between the inattention severity and fruit and vegetable intake in a select pediatric population enrolled in the st...
Preprint
Full-text available
Accumulating evidence supports the involvement of the gastrointestinal (GI) system in Alzheimer's disease (AD), however, it is currently unknown whether GI alterations arise as a consequence of central nervous system (CNS) pathology or play a causal role in the pathogenesis of the disease. The GI mucus system is a possible mediator of GI dyshomeost...
Article
Iconodiagnosis is the discipline that combines a medical and humanistic approach to provide a heuristic insight into the historical moment represented in the work of art by overlaying a presumable pathophysiological context. The concept of iconodiagnosis, first introduced in 1983 by a Harvard psychiatrist Anneliese Alma Pontius [Pontius, 1983] was...
Article
Full-text available
Aim: To assess whether exposure to proton pump inhibitors (PPIs) shortly preceding COVID-19 diagnosis affected the risk of subsequent hospitalizations and mortality. Methods: This population-based study embraced first COVID-19 episodes in adults diagnosed up to August 15 2021 in Croatia. Patients were classified based on exposure to PPIs and bur...
Preprint
Full-text available
The gut-brain axis plays an important role in Parkinson's disease (PD) by acting as a route for vagal propagation of aggregated α-synuclein in the gut-first endophenotype and as a mediator of gastrointestinal dyshomeostasis via the nigro-vagal pathway in the brain-first endophenotype of the disease. One important mechanism by which the gut-brain ax...
Preprint
Full-text available
Background Understanding molecular and biochemical mechanisms affecting biotribological properties of tissues, biological fluids, and drugs may accelerate the invention of novel drug formulations and targets and facilitate the discovery of etiopathogenetic mechanisms. Unfortunately, biotribometric equipment is expensive and unaffordable. The first...
Preprint
Full-text available
Bioanalytical techniques for the isolation and quantification of total lipids in biological samples are an integral part of lipidomic workflows and widely used tools for metabolic assessment at the cellular and organismic levels. The most widely used protocol for the isolation, extraction, and quantification of total lipids in biological tissues wa...
Article
Full-text available
Purpose: Dilated cardiomyopathy (DCM) is a primary disorder of the cardiac muscle, characterised by dilatation of the left ventricle and contractile dysfunction. About 50% of DCM cases can be attributed to monogenic causes, whereas the aetiology in the remaining patients remains unexplained. Methods: We report a family with two brothers affected...
Article
Tattoo inks are comprised of different combinations of bioactive chemicals with combined biological effects that are insufficiently explored. Tattoos have been associated with oxidative stress; however, a recent N-of-1 study suggested that blue tattoos may be associated with suppressed local skin oxidative stress. The present study aimed to explore...
Preprint
Full-text available
Background. Several studies assessed the effect of pre-morbid exposure to proton pump inhibitors (PPIs) on disease course in adult COVID-19 patients with somewhat inconsistent results. Methods. This population-based matched cohort study embraced first COVID-19 episodes in adults diagnosed up to August 15 2021 in Croatia. Considering over-the-counte...
Article
Background Assessment of neuromuscular function is critical for understanding pathophysiological changes related to motor system dysfunction in many rodent disease models. Among methods used for quantification of grip performance in rodents, gauge-based grip strength meters provide the most reliable results, however, such instruments are unaffordab...
Article
Full-text available
COVID-19-related (vs. non-related) articles appear to be more expeditiously processed and published in peer-reviewed journals. We aimed to evaluate: (i) whether COVID-19-related preprints were favored for publication, (ii) preprinting trends and public discussion of the preprints, and (iii) the relationship between the publication topic (COVID-19-r...
Preprint
Full-text available
Tattoo inks are comprised of different combinations of bioactive chemicals with combined biological effects that are insufficiently explored. Tattoos have been associated with oxidative stress; however, a recent N-of-1 study suggested that blue tattoos may be associated with suppressed local skin oxidative stress. The present study aimed to explore...
Preprint
Full-text available
Antioxidant enzyme catalase protects the cells against alcohol-induced oxidative stress by scavenging free radicals and metabolizing alcohol. Concentrations of ethanol present in alcoholic beverages can inhibit catalase and foster oxidative stress and alcohol-induced injury. Non-alcoholic components of pelinkovac counteract the inhibitory effects o...
Article
Full-text available
The incretin system is an emerging new field that might provide valuable contributions to the research of both the pathophysiology and therapeutic strategies in the treatment of diabetes, obesity, and neurodegenerative disorders. This study aimed to explore the roles of central glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP...
Chapter
Alzheimer's disease (AD) is the most common neurodegenerative disorder with yet unresolved etiopathogenesis that poses a significant socio-economical burden on society. At the molecular level, AD is driven by mutually interdependent pathophysiological processes with the ability to trigger self-sustaining progressive neurodegeneration. Redox homeost...
Article
Full-text available
Galactose is a ubiquitous monosaccharide with important yet incompletely understood nutritive and physiological roles. Chronic parenteral d-galactose administration is used for modeling aging-related pathophysiological processes in rodents due to its ability to induce oxidative stress (OS). Conversely, chronic oral d-galactose administration preven...
Preprint
Full-text available
Dear Editors, We read with great interest a study by Usher et al. who provide evidence to settle an age-old debate of which phrase—„It’s not brain surgery“ or „It’s not rocket science“—is most deserved to be considered a timeless antithesis to „a piece of cake“ or „a walk in the park“[1]. The main aim of the study presented by Usher et al. was „to...
Conference Paper
Full-text available
Introduction: The 6-hydroxydopamine rat model of Parkinson’s disease (PD) successfully mimics the gastrointestinal pathology and symptoms observed in patients. However, the differential effect of sham versus 6-hydroxydopamine treatment on gut redox homeostasis has never been systematically explored. Aim of the study: To examine the effects of bilat...
Article
Full-text available
We propose a rapid, simple, and robust method for measurement of the reductive capacity of liquid and solid biological samples based on potassium permanganate reduction followed by trapping of manganese dioxide precipitate on a nitrocellulose membrane. Moreover, we discuss how nitrocellulose redox permanganometry (NRP) can be used for high-throughp...
Article
Background: Our previous research indicated incretin dysregulation in a rat model of sporadic Alzheimer's disease (sAD) induced by intracerebroventricular streptozotocin (STZ-icv) and improvement of cognitive decline following oral galactose-induced potentiation of endogenous glucagon-like peptide 1 (GLP-1). This study explored peripheral GLP-1 re...
Preprint
Full-text available
Galactose is a ubiquitous monosaccharide with important yet incompletely understood nutritive and physiological roles. Chronic parenteral D-galactose administration is used for modeling aging-related pathophysiological processes in rodents due to its ability to induce oxidative stress (OS). Conversely, chronic oral D-galactose administration preven...
Poster
Full-text available
Circadian dysrhythmia has been recognized as a potential etiopathogenetic factor and an early sign of Alzheimer’s disease (AD) in humans. We aimed to explore the patterns of circadian dysrhythmia in a streptozotocin intracerebroventricularly-treated (STZ-icv) rat model of sporadic AD (sAD). Adult male Wistar rats were treated icv with STZ (3 mg/kg)...
Conference Paper
Full-text available
Introduction: Alzheimer's disease (AD) has been described more than 115 years ago, however, its etiopathogenesis remains unknown to date. Consequently, modeling of the disease in laboratory animals remains a challenge and the development of novel treatment solutions have been unsuccessful so far. Cognitive impairment is the most pronounced behavior...
Preprint
Full-text available
The incretin system is an emerging new field that might provide valuable contributions to the research of both pathophysiology and therapeutic strategies in the treatment of diabetes, obesity, and neurodegenerative disorders. This study aimed to explore the role of central glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) on...
Article
Full-text available
Background Epidemiological studies suggest an inverse association between H. pylori infection/exposure and inflammatory bowel disease prevalence/incidence, however, there are no reports of individual patients who developed a "non-transient” ulcerative colitis (UC) following H. pylori eradication. Case presentation We report a case of a 72-year-old...
Chapter
This chapter on current experimental models of Alzheimer’s disease (AD) is based on human post-mortem findings showing keystone markers for pathology within the ß-amyloid transduction cascade as well as pathology in the mechanism of phosphorylation of tau protein. Evidence for risk factors triggering this devastating disease focuses on type II diab...
Preprint
Full-text available
Alzheimer's disease (AD) is the most common neurodegenerative disorder with yet unresolved etiopathogenesis that poses a significant socio-economical burden on society. At the molecular level, AD is driven by mutually interdependent pathophysiological processes with the ability to trigger self-sustaining progressive neurodegeneration. Redox homeost...
Article
Full-text available
Dental health care workers, particularly dental medicine students (DMS), are at an increased risk of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. The aim of our study was to assess the level of knowledge on HBV and HCV, estimate needlestick injury (NSI) prevalence and reporting practice in DMS at the University of Zagreb, and anal...
Conference Paper
Full-text available
Alzheimer’s disease (AD) is the most common form of dementia, with the sporadic form (sAD) of unclear pathogenesis accounting for 95% of cases. Recent research highlights circadian rhythm changes as a potential factor in the etiopathogenesis of this disease and an early sign in humans, which develops before the onset of mild cognitive impairment, t...
Article
Almost 115 years ago, Alois Alzheimer described Alzheimer’s disease (AD) for the first time. Since then, many hypotheses have been proposed. However, AD remains a severe health public problem. The current medical approaches for AD are limited to symptomatic interventions and the complexity of this disease has led to a failure rate of approximately...
Preprint
Full-text available
Background: Dyshomeostasis of the gastrointestinal (GI) system is investigated as a potential contributor to metabolic dysfunction, systemic and neuro-inflammation recognized as important pathophysiological drivers of Alzheimer's disease. Gastrointestinal redox dyshomeostasis and dysfunctional brain-gut incretin axis have been reported in the rat...
Article
Biomedical aspects of tattooing have been extensively discussed in the literature, however pathophysiological effects of tattoo inks in the human body are still unexplored. Oxidative stress is considered responsible for the adverse effects of tattooing, however, no experimental evidence for tattoo ink-related oxidative stress in the human body curr...
Preprint
Full-text available
The gastrointestinal system may be involved in the etiopathogenesis of the insulin-resistant brain state (IRBS) and Alzheimer’s disease (AD). Gastrointestinal hormone glucagon-like peptide-1 (GLP-1) is being explored as a potential therapy as activation of brain GLP-1 receptors (GLP-1R) exerts neuroprotection and controls peripheral metabolism. Int...
Preprint
Full-text available
Galactose is a ubiquitous simple monosaccharide with yet incompletely understood biochemical and physiological role. Most of what we currently know about galactose is based on induction from the research on inherited disorders of galactose metabolism and animal models that exploit galactose-induced oxidative stress to model aging in rodents, howeve...
Article
Full-text available
Widely available low-cost electronics encourage the development of open-source tools for neuroscientific research. In recent years, many neuroscientists recognized the open science movement for its potential to stimulate and encourage science that is less focused on money, and more on robustness, validity, questioning and understanding. Here, we wa...
Data
Supplementary Material for "Virag et al. Repurposing a digital kitchen scale for neuroscience research: a complete hardware and software cookbook for PASTA (2021)"
Article
Full-text available
A recent article by Ghosh et al. entitled "Optimization of intracerebroventricular streptozotocin dose for the induction of neuroinflammation and memory impairments in rats" provides an important new set of information on neuroinflammation and cognitive deficit in a rat model of sporadic Alzheimer's disease (sAD) based on intracerebroventricular ad...
Preprint
Full-text available
We read with great interest a recent paper in Clinical Drug Investigation by Charpiat et al. entitled “Proton Pump Inhibitors are Risk Factors for Viral Infections: Even for COVID-19?” [1]. The authors discuss potential implications of the use of proton pump inhibitors (PPI) amidst the COVID-19 pandemic and suggest they should be used with caution...
Chapter
The understanding of Alzheimer's disease (AD) pathophysiology is an active area of research, and the traditional focus on hippocampus, amyloid and tau protein, and memory impairment has been expanded with components like neuroinflammation, insulin resistance, and circadian rhythm alterations. The bidirectional vicious cycle of neuroinflammation and...
Article
Sporadic Alzheimer’s disease (sAD) is the most common form of dementia. Central administration of streptozotocin (STZ‐icv) has been shown to induce Alzheimer‐like changes and has been proposed as a non‐transgenic sAD animal model. Intranasal insulin administration is being investigated as a possible pharmacological treatment in order to reverse and...
Article
Long‐term oral galactose treatment prevents and rescues cognitive deficits in rat model of Alzheimer's disease. In contrast, long‐term parenteral galactose treatment‐induced oxidative stress is used to model aging in rodents. The aim of this study was to provide new information on the effects of single acute oral galactose treatment, elucidate mech...
Preprint
Full-text available
Introduction: COVID-19-related (vs. non-related) articles appear to be more expeditiously processed and published in peer-reviewed journals. We aimed to evaluate: (i) whether COVID-19-related preprints were favored for publication, (ii) preprinting trends and public discussion of the preprints, and (iii) the relationship between the publication top...
Preprint
Full-text available
Chronic parenteral administration of D-galactose has been used to model oxidative stress-related pathophysiological mechanisms driving senescence and neurodegeneration in rodents for several decades, especially in animal research on potential anti-aging therapeutics. The exact mechanism responsible for the oxidative stress induced by galactose stil...
Preprint
Full-text available
A suggested effect of air temperature on severity of COVID-19 in hospitalized patients by Kifer et al. (Effects of environmental factors on severity and mortality of COVID
Poster
Full-text available
Hormetic effects of galactose could be explained by rapid metabolic network disinhibition of the protective oxidative pentose phosphate pathway flux
Preprint
Full-text available
Assessment of neuromuscular function is critical for understanding pathophysiological changes related to motor system dysfunction in many rodent disease models. Among methods used for quantification of grip performance in rodents, gauge-based grip strength meters provide the most reliable results, however, such instruments are unaffordable by many...
Preprint
Full-text available
Introduction: A large number of COVID-19 publications has created a need to collect all research-related material in practical and reliable centralized databases. The aim of this study was to evaluate the functionality and quality of the compiled World Health Organisation COVID-19 database and compare it to Pubmed and Scopus. Methods: Article metad...
Article
The Pandemic of COVID-19, an infectious disease caused by SARS-CoV-2 motivated the scientific community to work together in order to gather, organize, process and distribute data on the novel biomedical hazard. Here, we analyzed how the scientific community responded to this challenge by quantifying distribution and availability patterns of the aca...