A MicroRNA Derived from Adenovirus Virus-Associated RNAII Promotes Virus Infection via Posttranscriptional Gene Silencing.

The adenovirus (Ad) serotype 5 genome encodes two noncoding small RNAs (virus-associated RNAs I and II [VA-RNAI and -II]), which are approximately 160-nucleotide (nt) RNAs transcribed by RNA polymerase III. It is well known that VA-RNAI supports Ad infection via the inhibition of double-stranded RNA-dependent protein kinase (PKR), which recognizes double-stranded RNA and acts as an antiviral system. Recent studies revealed that VA-RNAs are processed into VA-RNA-derived microRNAs (miRNAs) (mivaRNAI and -II); however, we and another group recently demonstrated that mivaRNAI does not promote Ad replication. On the other hand, the roles of VA-RNAII and mivaRNAII in Ad replication have remained to be clarified. In this study, we demonstrated mivaRNAII-mediated promotion of Ad replication. Transfection with chemically synthesized 3'-mivaRNAII-138, one of the most abundant forms of mivaRNAII, significantly enhanced Ad replication, while the other species of mivaRNAII did not. We identified 8 putative target genes of 3'-mivaRNAII-138 by microarray analysis and in silico analysis. Among the 8 candidates, knockdown of the cullin 4A (CUL4A) gene, which encodes a component of the ubiquitin ligase complex, most significantly enhanced Ad replication. CUL4A expression was significantly suppressed by 3'-mivaRNAII-138 via posttranscriptional gene silencing, indicating that CUL4A is a target gene of 3'-mivaRNAII-138 and mivaRNAII functions as a viral miRNA promoting Ad infection. It has been reported that CUL4A is involved in degradation of c-Jun, which acts as a transcription factor in the Jun-N-terminal kinase (JNK) signaling cascade. Treatment with JNK inhibitors dramatically suppressed Ad replication, suggesting that mivaRNAII-mediated downregulation of CUL4A enhanced JNK signaling and thereby promoted Ad infection.IMPORTANCE Several types of viruses encode viral miRNAs which regulate host and/or viral gene expression via posttranscriptional gene silencing, leading to efficient viral infection. Adenovirus (Ad) expresses miRNAs derived from VA-RNAs (mivaRNAI and -II); however, recent studies have revealed that processing of VA-RNAI into mivaRNAI inhibits Ad replication. Conversely, we demonstrate here that mivaRNAII significantly promotes Ad replication and that mivaRNAII-mediated suppression of CUL4A expression via posttranscriptional gene silencing induces accumulation of c-Jun, leading to promotion of Ad infection. These results exhibited the significance of VA-RNAII for supporting Ad infection through a mechanism complementary to that of VA-RNAI. These observations could provide important clues toward a new perspective on host-virus interaction. Moreover, Ad is widely used as a basic framework for viral vectors and oncolytic viruses. Our findings will help to regulate Ad infection and will promote the development of novel Ad vectors and oncolytic Ad.

Clinical and pathological features affecting cardiac sympathetic denervation in autopsy-confirmed dementia with Lewy bodies.

BACKGROUND AND PURPOSE: The aim was to clarify the features affecting cardiac sympathetic denervation in autopsy-confirmed dementia with Lewy bodies (DLB) patients. METHODS: Fifty-four autopsy-confirmed DLB patients were enrolled. Tissue samples of the left ventricular anterior wall were immunostained with anti-tyrosine hydroxylase antibody to identify catecholaminergic nerve axons. Immunostained areas were quantified as residual cardiac sympathetic nerve (CSN) axons and the relationship between the degree of residual CSN axons and clinical and neuropathological features was examined. RESULTS: Virtually all patients showed small amounts of residual CSN axons (0.87%, range 0.02%-9.98%), with 50 patients (92.6%) showing <2.0% of residual axons. The patients who showed psychological symptoms within the first year of the disease had significantly more residual CSN axons than the remaining patients did (1.50% vs. 0.40%, P < 0.01). Patients with a short disease duration and neocortical-type Lewy body pathology tended to have more preserved CSN axons, although this difference was not statistically significant. Fifty-three patients (98.1%) who had neurofibrillary tangles in the brain and strong concomitant Alzheimer's disease pathology also had statistically significantly more preserved CSN axons. The patient with the most preserved CSN axons showed different characteristics from the results, except for the first symptom. CONCLUSION: Psychological symptoms within the first year of the disease, a short disease duration, neocortical-type Lewy body pathology and strong concomitant Alzheimer's disease pathology may be related to mild CSN degeneration in DLB patients. Thus, DLB patients with broad Lewy body pathology in the brain in the early stages may show mild CSN degeneration.

γ-H2AX formation in the urinary bladder of rats treated with two norharman derivatives obtained from o-toluidine and aniline.

Aminomethylphenylnorharman (AMPNH) and aminophenylnorharman (APNH) are mutagenic norharman derivatives obtained from o-toluidine and aniline, respectively. APNH is carcinogenic to the urinary bladder of rats and present in urine samples of healthy volunteers, indicating that norharman derivatives may be associated with cancer development in the urinary bladder of humans. To evaluate the possible role of AMPNH and APNH in bladder carcinogenesis, we examined the formation of γ-H2AX, a DNA damage response marker, in the urinary bladder of rats. Seven-week-old male F344 rats were treated with 400 ppm AMPNH or 40 ppm APNH in the diet for 4 weeks. Animals were killed at the end of administration or after 2 weeks of recovery, and immunohistochemistry for γ-H2AX and Ki67, a cell proliferation marker, was performed. At week 4, γ-H2AX formation in bladder epithelial cells was significantly increased by APNH treatment as compared with that in controls. AMPNH also induced upregulation of γ-H2AX formation, although there was no statistical significance. After the recovery period, γ-H2AX-positive cells were reduced but remained significantly higher in AMPNH and APNH groups than in the control group. Ki67-positive cells were significantly increased by AMPNH and APNH at week 4 and reduced to the same level as the control after 2 weeks of recovery. Expression of KRT14, a bladder stem cell marker, was also increased in the basal layer by the two norharman derivatives. Thus, AMPNH and APNH showed in vivo genotoxicity in the bladder epithelium of rats, and APNH may be a potent causative agent of bladder carcinogenesis.

Co-occurrence of argyrophilic grain disease in sporadic amyotrophic lateral sclerosis.

AIMS: Phosphorylated TDP-43 (pTDP-43) is the pathological protein responsible for amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease. Recently, it has been reported that accumulation of pTDP-43 can occur in the brains of patients with argyrophilic grain disease (AGD), in which phosphorylated 4-repeat tau is the pathological protein. To elucidate the association of ALS with AGD, we examined the brains from 37 consecutively autopsied patients with sporadic ALS (age range 45-84 years, mean 71.5 ± 9.0 years). METHODS: Sections from the frontotemporal lobe were stained with the Gallyas-Braak method and also immunostained with antibodies against phosphorylated tau, 4-repeat tau and pTDP-43. RESULTS: Fourteen (38%) of the 37 ALS patients were found to have AGD. With regard to staging, 5 of these 14 cases were rated as I, 4 as II and 5 as III. pTDP-43 immunohistochemistry revealed the presence of positive neuronal and glial cytoplasmic inclusions in the affected medial temporal lobe in many cases (93% and 64%, respectively). On the other hand, pTDP-43-positive small structures corresponding to argyrophilic grains were observed only in one case. A significant correlation was found between AGD and the Braak stage for neurofibrillary pathology (stage range 0-V, mean 2.1). However, there were no significant correlations between AGD and any other clinicopathological features, including dementia. CONCLUSIONS: The present findings suggest that co-occurrence of AGD in ALS is not uncommon, and in fact comparable with that in a number of diseases belonging to the tauopathies or α-synucleinopathies.

FUS immunoreactivity of neuronal and glial intranuclear inclusions in intranuclear inclusion body disease.

AIMS: Recent studies have shown that fused-in-sarcoma (FUS) protein is a component of 'neuronal' intranuclear inclusion bodies (INIBs) in the brains of patients with intranuclear inclusion body disease (INIBD). However, the extent and frequency of FUS-immunoreactive structures in INIBD are uncertain. METHODS: We immunohistochemically examined the brain, spinal cord and peripheral ganglia from five patients with INIBD and five control subjects, using anti-FUS antibodies. RESULTS: In controls, the nuclei of both neurones and glial cells were intensely immunolabelled with anti-FUS and neuronal cytoplasm was weakly positive for FUS. In INIBD, neuronal and glial INIBs in the brain and spinal cord were positive for FUS. FUS-positive INIBs were also found in the peripheral ganglia. The proportion of FUS-positive neuronal INIBs relative to the total number of inclusion-bearing neurones ranged from 55.6% to 83.3% (average 73.2%) and that of FUS-positive glial INIBs ranged from 45.9% to 85.7% (average 62.7%). The nucleus and cytoplasm of inclusion-bearing neurones and glial cells showed no FUS immunoreactivity. CONCLUSIONS: These findings suggest that FUS is incorporated into INIBs in both neurones and glial cells and that loss of normal FUS immunoreactivity may result from reduced protein expression and/or sequestration within inclusions.

Dual epidural catheter technique to provide opioid-free anaesthesia for an open abdominoperineal resection.

The peri-operative analgesic management of patients undergoing major elective colorectal surgery has an impact on patient recovery. An approach that favours an opioid-free strategy has demonstrated improved patient outcomes. Avoiding systemic opioids during and after abdominal surgery promotes early recovery of bowel function and early re-initiation of oral intake, shortens hospital length of stay, minimises postoperative complications, and may improve long-term outcomes. In this case report we describe an opioid-free anaesthetic technique, in line with current Enhanced Recovery After Surgery recommendations, for a patient undergoing an open abdominoperineal resection who reported experiencing severe side-effects to opioids in the past. Two epidural catheters were sited pre-operatively at the interspaces between the ninth and tenth thoracic and third and fourth lumbar vertebrae respectively, and used intra- and postoperatively. The utilisation of two epidural catheters not only ensured complete peri-operative analgesia, but also successfully attenuated the neuroendocrine stress response to surgery. The dual epidural catheter technique may be considered for extensive colorectal surgery when conventional opioid-based anaesthetic techniques are contraindicated.

Unmyelinated axons are more vulnerable to degeneration than myelinated axons of the cardiac nerve in Parkinson's disease.

AIMS: We recently demonstrated accumulation of α-synuclein aggregates of the cardiac sympathetic nerve in Parkinson's disease (PD) and a possible relationship between degeneration of the cardiac sympathetic nerve and α-synuclein aggregates. The aim of this study is to determine whether there is a difference in the degenerative process between unmyelinated and myelinated axons of the cardiac nerve. METHODS: We immunohistochemically examined cardiac tissues from four pathologically verified PD patients, nine patients with incidental Lewy body disease (ILBD) and five control subjects, using antibodies against neurofilament, myelin basic protein (MBP) and α-synuclein. First, we counted the number of neurofilament-immunoreactive axons not surrounded by MBP (unmyelinated axons) and those surrounded by MBP (myelinated axons). Next, we counted the number of unmyelinated and myelinated axons with α-synuclein aggregates. RESULTS: (i) The percentage of unmyelinated axons in PD (77.5 ± 9.14%) was significantly lower compared to that in control subjects (92.2 ± 2.40%). (ii) The ratio of unmyelinated axons with α-synuclein aggregates to total axons with α-synuclein aggregates in ILBD ranged from 94.4 to 100 (98.2 ± 2.18%). Among axons with α-synuclein aggregates, unmyelinated axons were the overwhelming majority, comprising 98.2%. CONCLUSION: These findings suggest that in PD unmyelinated axons are more vulnerable to degeneration than myelinated axons of the cardiac nerve, because α-synuclein aggregates accumulate much more abundantly in unmyelinated axons.

Relationship between Bunina bodies and TDP-43 inclusions in spinal anterior horn in amyotrophic lateral sclerosis.

AIMS: Amyotrophic lateral sclerosis (ALS) is characterized by upper and lower motor neurone involvement with Bunina bodies (BBs) and TDP-43 inclusions. To elucidate the relationship between BBs and TDP-43 inclusions, we examined the spinal cord from 18 patients with ALS. METHODS: Five serial sections from lumbar cord were first stained with haematoxylin and eosin to detect BBs and subsequently immunostained with anti-TDP-43 antibody. Immunoelectron microscopy was performed on vibratome sections from two cases of ALS. RESULTS: BBs were found in 15 out of 18 cases. TDP-43 inclusions were found in all the cases. The average incidence of anterior horn cells with BBs and TDP-43 inclusions relative to the total number of neurones was 17.1% and 46.4%, respectively. The concurrence of both inclusions in the same neurones was found in 15 cases. The incidence of co-localization of BBs and TDP-43 inclusions was 15.7% of total neurones. The frequency of TDP-43 inclusions was significantly higher in neurones with BBs than in those without. Ultrastructurally, TDP-43-immunoreactive filamentous structures were intermingled with early-stage BBs, but not associated with advanced-stage BBs. CONCLUSION: These findings suggest that there is a close relationship in the occurrence between BBs and TDP-43 inclusions.

The phenotype spectrum of Japanese multiple system atrophy.

OBJECTIVE: This study aimed to determine the spectrum of pathological involvement of the striatonigral (StrN) and olivopontocerebellar (OPC) systems in Japanese patients with multiple system atrophy (MSA). This study also aimed to compare the pathological spectrum of Japanese MSA patients with the previously reported results in British MSA patients. METHODS: A semiquantitative pathological analysis of 50 MSA patients' brains that were referred to the Brain Research Institute, Niigata University, Japan, was performed. The severity of neuronal cell loss was determined as previously described by the study from the Queen Square Brain Bank (QSBB), UK. RESULTS: The mean neuronal cell loss score was significantly higher in the OPC area than in the basal ganglia sites examined, except the dorsolateral putamen. The relative prevalence of pathological phenotypes showed that 40% of cases had OPC-predominant pathology, 18% had StrN-predominant pathology and the remaining (42%) had equivalent StrN and OPC pathology. None of the MSA cases had coexistent Lewy bodies in the dorsal motor nucleus of the vagus and the substantia nigra. CONCLUSIONS: In contrast to the previously reported results involving British patients' brains from the QSBB (OPC-predominant pathology 17%, StrN-predominant pathology 34%, equivalent StrN and OPC pathology 49%), the results of the present study showed more pathological involvement of the OPC system than of the StrN system. The rarity of Lewy bodies may underlie the phenotypic expression of Japanese MSA. The present observations reflect the disequilibrium in the phenotype distribution between the two populations.

Induction of autoimmune cholangitis in non-obese diabetic (NOD).1101 mice following a chemical xenobiotic immunization.

Our laboratory has suggested that loss of tolerance to pyruvate dehydrogenase (PDC-E2) leads to an anti-mitochondrial antibody response and autoimmune cholangitis, similar to human primary biliary cirrhosis (PBC). We have suggested that this loss of tolerance can be induced either via chemical xenobiotic immunization or exposure to select bacteria. Our work has also highlighted the importance of genetic susceptibility. Using the non-obese diabetic (NOD) congenic strain 1101 (hereafter referred to as NOD.1101 mice), which has chromosome 3 regions from B6 introgressed onto a NOD background, we exposed animals to 2-octynoic acid (2OA) coupled to bovine serum albumin (BSA). 2OA has been demonstrated previously by a quantitative structural activity relationship to react as well as or better than lipoic acid to anti-mitochondrial antibodies. We demonstrate herein that NOD.1101 mice immunized with 2OA-BSA, but not with BSA alone, develop high titre anti-mitochondrial antibodies and histological features, including portal infiltrates enriched in CD8(+) cells and liver granulomas, similar to human PBC. We believe this model will allow the rigorous dissection of early immunogenetic cause of biliary damage.

Laser-stimulated luminescence used to measure x-ray diffraction of a contracting striated muscle.

An integrating x-ray area detector that operates on the basis of laser-stimulated luminescence was used in a diffraction study of muscle contraction. The area detector has a dynamic range of 1 to 10(5), a sensitivity about 60 times greater with approximately 1/300 as much fog background as x-ray film. It is erasable and reusable but, like film, can integrate at a practically unlimited counting rate. The high sensitivity and wide dynamic range of the detector resulted in a sufficient reduction in the exposure time to make possible the recording of a clear x-ray diffraction pattern, with up to 2.0-nanometer axial spacing, from a contracting frog skeletal muscle in as little as 10 seconds with synchrotron radiation. During the isometric contraction of the muscle, most of the actin diffraction lines increased in intensity without noticeable changes in their peak positions. Changes also occurred in diffraction intensities from the myosin heads. The results indicate that during contraction the structure of the actin filaments differs from that in the rigor state, suggesting a possible structural change in the actin subunits themselves; the myosin heads during contraction retain the axial periodicity of the myosin filament and become aligned in a more perpendicular manner to the actin filaments.

Small-angle synchrotron x-ray scattering reveals distinct shape changes of the myosin head during hydrolysis of ATP.

In the energy transduction of muscle contraction, it is important to know the nature and extent of conformational changes of the head portion of the myosin molecules. In the presence of magnesium adenosine triphosphate (MgATP), fairly large conformational changes of the myosin head [subfragment-1 (S1)] in solution were observed by small-angle x-ray scattering with the use of synchrotron radiation as an intense and stable x-ray source. The presence of MgATP reduced the radius of gyration of the molecule by about 3 angstrom units and the maximum chord length by about 10 angstroms, showing that the shape of S1 becomes more compact or round during hydrolysis of MgATP. Comparison with various nucleotide-bound S1 complexes that correspond to the known intermediate states during ATP hydrolysis indicates that the shape of S1 in a key intermediate state, S1-bound adenosine diphosphate (ADP) and phosphate [S1**.ADP.P(i)], differs significantly from the shape in the other intermediate states of the S1 adenosine triphosphatase cycle as well as that of nucleotide-free S1.

Elevated serum levels of soluble CX3CL1 in patients with microscopic polyangiitis.

OBJECTIVES: To test the hypothesis that CX3CL1 contributes to the pathogenesis of microscopic polyangiitis. METHODS: Serum samples from 18 patients with microscopic polyangiitis (MPA), who fulfilled the revised criteria of the American College of Rheumatology (ACR), were collected during both the newly diagnosed, untreated active disease states and inactive disease states. Also serum was from patients with large vessel vasculitis (LVV), including giant cell arteritis (n=4) and Takayasu arteritis (n=3), and from 52 healthy individuals. Soluble (s)CX3CL1 levels in serum were measured using an enzyme-linked immunosorbent assay. Disease activity was assessed using Birmingham vasculitis activity scores (BVAS). Expression of CX3CR1 was examined by flow cytometry. RESULTS: Serum sCX3CL1 levels were significantly higher in MPA patients than in either LVV group or healthy individuals. The elevated sCX3CL1 levels seen in MPA patients correlated positively with BVAS, as well as with CRP levels and ESR, and similarly increased expression of cell-surface CX3CR1 was seen on peripheral blood CD4 and CD8 T cells from patients with MPA. Notably, sCX3CL1 levels and CX3CR1 expression were diminished during clinical remission following treatment. CONCLUSION: Our findings suggest that CX3CL1 may be involved in the pathogenesis of MPA, and may serve as a useful serologic marker of disease activity in systemic vasculitis.

A comparison of the physiological, behavioral, neurochemical and microglial effects of methamphetamine and 3,4-methylenedioxymethamphetamine in the mouse.

3,4-Methylenedioxymethamphetamine (MDMA) and methamphetamine (METH) are amphetamine analogues with similar persistent neurochemical effects in the mouse which some have described as neurotoxicity. We attempted to identify dose regimens of MDMA and METH with similar effects on behavioral and physiological variables in the mouse, then quantified the effects of these dose regimens on neurochemistry and microglial markers. Four discrete injections of saline, MDMA (10, 20, or 30 mg/kg), or METH (5 or 10 mg/kg) were administered to mice at 2 h intervals. Body weight was quantified immediately before each injection, and 2 h after the last injection, while core temperature and locomotor activity were continuously monitored via radiotelemetry. Mice were killed 72 h after the final injection and brains were rapidly dissected on ice. Dopamine content in various brain regions was quantified via high pressure liquid chromatography (HPLC), and microglial activation was assessed by saturation binding of the peripheral benzodiazepine receptor (PBR) ligand 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide ([(3)H]PK11195). Specific dose regimens of MDMA and METH induced similar reductions in body weight, depletions of dopamine and its metabolites, and similar hyperthermic and locomotor stimulant effects, but only METH activated microglia in striatum. These results suggest that repeated high doses of MDMA and METH that produce hyperthermia, locomotor stereotypy, weight loss and neurochemical depletion are not consistently accompanied by microglial activation. The finding that METH, but not MDMA, induces microglial effects in the striatum consistent with neurotoxicity might imply different mechanisms of toxic action for these two psychostimulants.

Human ABC transporters ABCG2 (BCRP) and ABCG4.

1. The human ABC transporter ABCG2 is regarded as a member of the phase III system for xenobiotic metabolism, and it has been suggested that this efflux pump is responsible for protecting the body from toxic xenobiotics and for removing metabolites. 2. This review paper will address the new aspects of ABCG2 in terms of post-translational modifications (i.e., disulfide bond formation, ubiquitination, and endoplasmic reticulum-associated degradation) of ABCG2 protein, high-speed screening, and quantitative structure-activity relationship (QSAR) analysis to evaluate ABCG2-drug interactions, and genetic polymorphisms potentially associated with photosensitivity. 3. In addition, new aspects of human ABCG4 and mouse Abcg4 are presented with respect to their molecular properties and potential physiological roles. Considering a high sequence similarity between ABCG1 and ABCG4, both Abcg4 and ABCG4 may be involved in the transport of cholesterol from neurons and astrocytes. Furthermore, high expression of the mouse Abcg4 protein in the testis implicates its involvement in transport of certain sex hormones.

Betacellulin and activin A coordinately convert amylase-secreting pancreatic AR42J cells into insulin-secreting cells.

Rat pancreatic AR42J cells possess exocrine and neuroendocrine properties. Activin A induces morphological changes and converts them into neuron-like cells. In activin-treated cells, mRNA for pancreatic polypeptide (PP) but not that for either insulin or glucagon was detected by reverse transcription-PCR. About 25% of the cells were stained by anti-PP antibody. When AR42J cells were incubated with betacellulin, a small portion of the cells were stained positively with antiinsulin and anti-PP antibodies. The effect of betacellulin was dose dependent, being maximal at 2 nM. Approximately 4% of the cells became insulin positive at this concentration, and mRNAs for insulin and PP were detected. When AR42J cells were incubated with a combination of betacellulin and activin A, approximately 10% of the cells became insulin positive. Morphologically, the insulin-positive cells were composed of two types of cells: neuron-like and round-shaped cells. Immunoreactive PP was found in the latter type of cells. The mRNAs for insulin, PP, glucose transporter 2, and glucokinase, but not glucagon, were detected. Depolarizing concentration of potassium, tolbutamide, carbachol, and glucagon-like peptide-1 stimulated the release of immunoreactive insulin. These results indicate that betacellulin and activin A convert amylase-secreting AR42J cells into cells secreting insulin. AR42J cells provide a model system to study the formation of pancreatic endocrine cells.

Generation of functionally distinct B lymphocytes from common myeloid progenitors.

Current models of adult haematopoiesis propose that haematopoietic stem cells (HSCs) differentiate into common lymphoid (CLP) and common myeloid (CMP) progenitors and establish an early separation between myeloid and lymphoid lineages. Nevertheless, the developmental potential of CMP-associated B cells suggests the existence of alternate pathways for B lymphopoesis. The aim of this study was to compare the developmental and functional properties of CMP- and CLP-derived B cells. While both populations matured through pro-B cell and transitional B cell intermediates in the bone marrow and spleen, respectively, following transfer into irradiated mice, mature CMP- and CLP-derived B cells exhibit distinct functional responses. Specifically, CMP-derived B cells did not respond to mitogenic stimulation to the same degree as their CLP-derived counterparts and secrete lower levels of IgM and the inflammatory cytokines such as interleukin (IL)-6 and IL-10. Together, these data suggest the existence of multiple pathways for generating functionally distinct B cells from bone marrow precursors.

Liquid chromatography-tandem mass spectrometry analysis of 2-amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5-b]pyridine in cooked meats.

Several cooked meats such as beef (fried, coated-fried), pork (fried, coated-fried), and chicken (fried, griddled, coated-fried, roasted) were analyzed for the heterocyclic amine 2-amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5- b]pyridine (4'-OH-PhIP) not commonly determined in food and 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP). The highest content of 4'-OH-PhIP was found in fried and griddled chicken breast, the concentration being 43.7 and 13.4 ng/g, respectively, whereas the corresponding PhIP concentrations were 19.2 and 5.8 ng/g. The estimated concentration of both pyridines in fried pork loin, in fried pork sausages, and in coated-fried chicken was below 2.5 ng/g. In the rest of the samples, 4'-OH-PhIP was not detected. The analyses were performed by solid-phase extraction and LC-MS/MS. The fragmentation of 4'-OH-PhIP in an ion trap mass analyzer was studied in order to provide information for the identification of 4'-OH-PhIP. Additionally, the effect of red wine marinades on the formation of 4'-OH-PhIP in fried chicken was examined, finding a notable reduction (69%) in the amine's occurrence.