YRNA and tRNA fragments can differentiate benign from malignant canine mammary gland tumors.

Mammary gland tumors (MGT) are the most common tumors in sexually intact female dogs. The functional regulation of miRNAs, a type of noncoding RNAs (ncRNAs), in canine MGT has been extensively investigated. However, the expression of other ncRNAs, such as YRNAs and transfer RNA-derived fragments (tRFs) in canine MGT is unknown. We investigated ncRNAs other than miRNAs from our small RNA project (PRJNA716131) in different canine MGT histologic subtypes. This study included benign tumors (benign mixed tumor, complex adenoma) and malignant tumors (carcinoma in benign tumor and carcinoma with metastasis) samples. Aberrantly expressed ncRNAs were examined by comparisons among MGT subtypes. The relative expression trends were validated in canine MGT tissues, plasma, extracellular vesicles, and MGT cell lines using quantitative reverse transcription PCR. Three aberrantly expressed ncRNAs were identified by comparisons among MGT subtypes. YRNA and tRNA-Gly-GCC distinguished benign mixed tumor from other MGT histologic subtypes, while tRNA-Val differentiated complex adenoma, carcinoma in benign tumors, and carcinoma with metastasis. The ROC curve of the three ncRNAs showed they might be potential biomarkers to discriminate malignant from benign MGT. YRNA and tRFs expression levels were decreased in metastatic compared with primary canine MGT cell lines. To the best of our knowledge, this is the first investigation of YRNA and tRFs in canine MGT. The three identified ncRNAs may be biomarkers for differentiating MGT histologic subtypes. Suggested Reviewers: Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporatio.

Subchronic tolerance trials of graded oral supplementation with ornithine hydrochloride or citrulline in healthy adults.

Ornithine and citrulline are amino acids used in dietary supplements and nutritional products consumed by healthy consumers, but the safe supplementation levels of these compounds are unknown. The objective of this study was to conduct two 4-week clinical trials to evaluate the safety and tolerability of graded dosages of oral ornithine (as hydrochloride) and citrulline. Healthy male adults (n = 60, age 41.4 ± 1.5 years) completed graded dosages of either ornithine hydrochloride (3.2, 6, 9.2, and 12 g/day) or citrulline (6, 12, 18, and 24 g/day) supplement for 4 weeks with 2-week wash-out periods in between. Primary outcomes included vitals, a broad spectrum of circulating biochemical analytes, body weight, sleep quality, and mental self-assessment. In the ornithine hydrochloride supplementation group, minor increase in plasma aspartic acid and glutamic acid concentrations was observed at the highest intake dosages. In the citrulline supplementation group, minor changes in laboratory data for serum lactate dehydrogenase and plasma amino acid concentration of lysine, methionine, threonine, aspartic acid, glutamic acid, glutamine and ornithine, arginine, and citrulline itself were measured. No other changes in measured parameters were observed, and study subjects tolerated 4-week-long oral supplementation of ornithine hydrochloride or citrulline without treatment-related adverse events. A clinical, no-observed-adverse-effect-level (NOAEL) of ornithine hydrochloride and citrulline supplementation in healthy adult males was determined to be 12 g/day and 24 g/day (4 weeks), respectively.

microRNAs Are Abundant and Stable in Platelet-Rich Fibrin and Other Autologous Blood Products of Canines.

Various microRNAs (miRNAs) present in autologous blood products of canines have not been studied recently. We aimed to elucidate the existence of miRNAs in platelet-rich fibrin (PRF) and the stability of canine autologous blood products under various storage conditions. Total RNAs were isolated from PRF and other autologous blood products following newly adapted protocols used in commercial kits for plasma and tissue samples. Quantitative real-time polymerase chain reaction analysis (qPCR) was used to detect miRNAs in autologous blood products. The miR-16, miR-21, miR-155, and miR-146a were abundant in PRF and other autologous blood products of canines. Furthermore, we found they could maintain stability under protracted freezing temperatures of -30 °C for at least one month. Our findings revealed that PRF might be a stable resource for various canine miRNAs.

Effects of diet containing astaxanthin on visual function in healthy individuals: a randomized, double-blind, placebo-controlled, parallel study.

Visual display terminal work has increased rapidly in recent years. Loss of visual acuity is an unfortunate associated effect. Here, we performed a randomized, placebo-controlled study in 60 healthy adults. Participants received a diet containing astaxanthin (9 mg/day) or placebo for 6 weeks. Visual acuity, functional visual acuity, and pupil constriction rate were measured before and after visual display terminal work. In participants aged ≥40 years, corrected visual acuity of the dominant eye after visual display terminal work at 6 weeks after intake demonstrated a higher protective effect of astaxanthin in the astaxanthin group vs the control group (p<0.05). In participants aged <40 years, no significant difference was seen between the astaxanthin and control groups. Moreover, no significant difference was found in functional visual acuity and pupil constriction rate between the astaxanthin and control groups. These results suggest astaxanthin reduces oxidative stress caused by visual display terminal work. Age-related reduction in ciliary muscle strength is likely the main detractor of visual acuity. Correspondingly, astaxanthin reduced visual display terminal work-induced visual stress in the middle-aged and elderly. This study was registered in the UMIN-CTR database (UMIN000043089).

Prune Juice Containing Sorbitol, Pectin, and Polyphenol Ameliorates Subjective Complaints and Hard Feces While Normalizing Stool in Chronic Constipation: A Randomized Placebo-Controlled Trial.

INTRODUCTION: The aim of this study was to determine the effectiveness of prune juice on chronic constipation. METHODS: We conducted a double-blind, randomized, placebo-controlled trial in Japanese subjects with chronic constipation. RESULTS: Prune intake significantly decreased hard and lumpy stools while increasing normal stool and not increasing loose and watery stools. Prune intake also ameliorated subjective complaints of constipation and hard stools, without alteration of flatulence, diarrhea, loose stools, or urgent need for defecation. There were no adverse events or laboratory abnormalities of liver or renal function after prune intake. DISCUSSION: Prune juice exerted an effective and safe natural food therapy for chronic constipation.

Effects of reduced exposure to cigarette smoking on changes in biomarkers of potential harm in adult smokers: results of combined analysis of two clinical studies.

Purpose: Nonconventional vapor products (NVP), designed to reduce exposure to cigarette smoke toxicants (CSTs), could cause changes in biomarkers of potential harm (BoPH). Although, NVPs reduced CSTs exposure compared to conventional cigarettes (CC), the changes in the BoPH values varied among the studies. Hence, further information on BoPH using NVPs is needed. Material and methods: The data of two similarly designed studies using a kind of NVP, a noncombustion and nonheating inhaler type of smokeless tobacco product (NCIT) used under 31-day confinement, were pooled, and the differences in 15 BoPH between smokers and nonsmokers at baseline and between the 1 mg tar CC (CC1) group and NCIT group at Day 28/29 were analyzed. Results: At baseline, the levels of eight BoPH (red blood cells, white blood cells, 8-epi-prostaglandin F2α, 8-hydroxy-2'-deoxyguanosine, malondialdehyde, 11-dehydrothromboxane B2, total cholesterol and glucose) were significantly different between smokers and nonsmokers. At Day 28/29, the levels of six BoPH were significantly different between NCIT and CC1 (8-epi-prostaglandin F2α, malondialdehyde, 11-dehydrothromboxane B2: CC1 > NCIT, total bilirubin, low-density lipoprotein cholesterol and total cholesterol: CC1 < NCIT). Conclusions: Reduced exposure to CSTs has favorable effects on BoPH associated with oxidative stress, antioxidant capacity and platelet activation/coagulation but not in lipid metabolism.

Development of a Model of Porcine Epidemic Diarrhea in Microminipigs.

Porcine epidemic diarrhea virus (PEDV) induces an often fatal gastrointestinal disease in piglets. In this study, we performed a PEDV infection experiment with the Microminipig, the smallest of experimental minipigs, as a novel small animal model. We orally inoculated a neonatal Microminipig with an intestinal homogenate of a PEDV-infected pig and housed it in a small cage originally designed for rats in an animal biosafety level 2 facility. The infected Microminipig showed the typical signs of porcine epidemic diarrhea (PED), such as watery diarrhea, loss of appetite and weight loss. We also recognized a high amount of excreted PEDV in its rectal swabs and villus atrophy of the small intestine. These results suggest that the Microminipig is a good small animal model for PED, which may contribute to a better understanding of the pathogenesis of PEDV.

Micro RNA Transcriptome Profile in Canine Oral Melanoma.

MicroRNAs (miRNAs) dysregulation contribute the cancer pathogenesis. However, the miRNA profile of canine oral melanoma (COM), one of the frequent malignant melanoma in dogs is still unrevealed. The aim of this study is to reveal the miRNA profile in canine oral melanoma. MiRNAs profile of oral tissues from normal healthy dogs and COM patients were compared by next-generation sequencing. Along with tumour suppressor miRNAs, we report 30 oncogenic miRNAs in COM. The expressions of miRNAs were further confirmed by quantitative real-time PCR (qPCR). Pathway analysis showed that deregulated miRNAs impact on cancer and signalling pathways. Three oncogenic miRNAs targets (miR-450b, 301a, and 223) from human study also were down-regulated in COM and had a significant negative correlation with their respective miRNA. Furthermore, we found that miR-450b expression is higher in metastatic cells and regulated MMP9 expression through a PAX9-BMP4-MMP9 axis. In silico analysis indicated that miR-126, miR-20b, and miR-106a regulated the highest numbers of differentially expressed transcription factors with respect to human melanoma. Chromosomal enrichment analysis revealed the X chromosome was enriched with oncogenic miRNAs. We comprehensively analyzed the miRNA's profile in COM which will be a useful resource for developing therapeutic interventions in both species.

Monitoring of Brain Oxygenation During and After Cardiopulmonary Resuscitation: A Prospective Porcine Study.

This study aimed to evaluate the usefulness of near-infrared time-resolved spectroscopy (TRS) for the monitoring of post-resuscitation encephalopathy. Cardiac arrest (CA) was induced in pigs by electrical stimuli; then, return of spontaneous circulation (ROSC) was achieved by direct current. The changes in cerebral oxygenation were analyzed by two methods: (1) the time-independent calculation based on the modified Beer-Lambert law (MBL), and (2) the curve-fitting method based on the photon diffusion theory (DT). The changes in reduced scattering coefficient (µs') in DT were also calculated. Post-resuscitation encephalopathy was evaluated by MRI findings. During CA, cerebral oxygen saturation (ScO2) decreased to the lowest level, and then gradually increased during the chest compression period. When ROSC was achieved, ScO2 (DT) increased further, but ScO2 (MBL) decreased transiently. This strange phenomenon disappeared when the scalp was peeled off and the probes were directly fixed to the cranial bone. In some cases, a sustained decrease in µs' was observed several hours after ROSC and, in such cases, MRI Diffusion Enhancement Image (DWI) showed findings suggestive of post-resuscitation encephalopathy. In conclusion, simultaneous monitoring of cerebral oxygenation with MBL and DT may provide more information about the vascular response of different layers. Also, the monitoring of µs' may help us to recognize the occurrence of post-resuscitation encephalopathy in real time.

Hypertension alters the endothelial-dependent biphasic response of bradykinin in isolated Microminipig basilar artery.

Angiotensin (Ang) II is known to promote vascular disease and hypertension, partly through its effect on vascular endothelium. Bradykinin (BK) is an endothelium-dependent agonist that induces relaxation followed by contraction of the porcine basilar artery through release of NO and PGF2α, respectively. In this study, we evaluated the effect of Ang II-induced hypertension on basilar artery responsiveness to BK in the Microminipig (MMPig). Ang II (200ng/kg/min) or vehicle was infused into MMPigs for 14days using an osmotic mini-pump and blood pressure was monitored regularly. The responsiveness of subsequently isolated basilar arteries was then measured using a micro organ bath system. MMPig basilar artery endothelial cells were cultured and stimulated with Ang II or vehicle for 48h. Mean blood pressure was significantly (P<0.05; n=5) higher in Ang II-infused MMPigs than in vehicle-infused MMPigs. In vitro, BK-induced endothelium-dependent dilation of isolated basilar artery specimens was abolished and BK-induced contraction was significantly increased (Emax: 15.85±2.42% and 56.54±2.71% of 60mM KCl in control and Ang II group respectively at 10-7M concentration of BK; P<0.01; n=5) in Ang II-infused MMPigs. Ang II stimulation of the endothelial cells significantly decreased (54.15% at 24h; P<0.05; n=three independent experiment performed in triplicate) the amount of BK-elicited NO and increased (44.27% at 24h; P<0.05; n=three independent experiment performed in triplicate) the amount of BK-elicited PGF2α. These results suggest that the decrease of NO and increase of PGF2α production from endothelial cells are responsible for cerebrovascular dysfunction in hypertension, possibly causing cerebrovascular contraction and thus increasing the risk of brain infarction.

Enteric lactoferrin attenuates the development of high-fat and high-cholesterol diet-induced hypercholesterolemia and atherosclerosis in Microminipigs.

Previously, we found that enteric lactoferrin (eLF) could reduce the visceral fat accumulation known to associate strongly with metabolic syndrome symptoms and consequently with an increased risk of atherosclerosis. In this study, the atherosclerosis-preventive potential of LF was assessed in a high-fat and high-cholesterol diet (HFCD)-induced hypercholesterolemia and atherosclerosis model using Microminipig™. Eight-week orally administered eLF remarkably reduced the HFCD-induced serum total and low-density lipoprotein cholesterol levels but not high-density lipoprotein cholesterol levels. A histological analysis of 15 arteries revealed that eLF systemically inhibited the development of atherosclerotic lesions. Pathway analysis using identified genes that characterized eLF administration in liver revealed significant changes in the steroid biosynthesis pathway (ssc00100) and all affected genes in this pathway were upregulated, suggesting that cholesterol synthesis inhibited by HFCD was recovered by eLF. In summary, eLF could potentially prevent the hypercholesterolemia and atherosclerosis through protecting homeostasis from HFCD-induced dysfunction of cholesterol metabolism.

A study to investigate changes in the levels of biomarkers of exposure to selected cigarette smoke constituents in Japanese adult male smokers who switched to a non-combustion inhaler type of tobacco product.

In a clinical study, changes in 14 biomarkers of exposures (BOEs) from 10 tobacco smoke constituents and mutagens detected by the urine mutagenicity test were investigated using a non-combustion inhaler type of tobacco product (NCIT) by switching from a conventional cigarette. This study was conducted in 80 Japanese healthy adult males with a 4-week residential, controlled, open-label, parallel group design. After randomization, 40 smokers used NCIT with approximately 750 aspirations, other 20 smokers smoked approximately 20 pieces of an assigned 1-mg ISO tar conventional cigarette (CC1) every day. Twenty non-smokers (NS) did not use any tobacco product. Under this study condition, switching from cigarette to NCIT showed significant reduction in all BOEs measured. On day 29, the levels of these BOEs were almost the same as those in the NS group, except BOEs of nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). This suggested that the exposure to 8 constituents and mutagens in the NCIT group was similar to that in the NS group, while the exposure to nicotine was higher. Although the precise exposure level to NNK was not estimated because of the long half-life of its BOE, it would be substantially lower in the NCIT group than in the CC1 group.

Hypoxia-related Y RNA fragments as a novel potential biomarker for distinguishing metastatic oral melanoma from non-metastatic oral melanoma in dogs.

Hypoxia may promote tumor progression, and hypoxically altered noncoding RNA (ncRNA) expression may play a role in metastasis. Canine oral melanoma (COM) frequently metastasizes, and ncRNA expression under hypoxia may be clinically significant. We aimed to elucidate ncRNA fragments whose expression is altered by hypoxia in COM-derived primary KMeC and metastatic LMeC cell lines using next-generation sequencing to validate these results in qRT-PCR, and then compare expression between metastatic and non-metastatic COM. The NGS analysis and subsequent qRT-PCR validation were performed using hypoxic and normoxic KMeC and LMeC cells, and clinical samples [tumor tissue, plasma, and plasma-derived extracellular vesicles] obtained from dogs with metastatic or non-metastatic melanoma were analyzed with qRT-PCR. Y RNA was significantly decreased in metastatic LMeC cells versus primary KMeC cells in hypoxic and normoxic conditions. The expression of Y RNA was decreased in dogs with metastatic melanoma versus those with non-metastatic melanoma for all clinical sample types, reflecting the pattern found with hypoxia. Receiver operating characteristic analysis demonstrated that Y RNA level is a promising biomarker for discriminating metastatic from non-metastatic melanoma in plasma [area under the curve (AUC) = 0.993, p < 0.0001] and plasma-derived extracellular vesicles (AUC = 0.981, p = 0.0002). Overall, Y RNA may be more resistant to hypoxic stress in the metastatic than the non-metastatic state for COM. However, further investigation is required to elucidate the biological functions of Y RNA under hypoxic conditions.

Development of a Microminipig Model of Atherosclerosis for the Evaluation of a HMGCR Inhibitor.

BACKGROUND/AIM: Atherosclerosis is known as a major risk factor for cardiovascular disease, and development of an animal model of atherosclerosis is required to investigate its clinical pathogenesis. We studied the optimal amount of cholesterol in the diet and the optimal experimental period for development of a Microminipig model of atherosclerosis for the evaluation of a hydroxymethylglutaryl-CoA reductase (HMGCR) inhibitor (atorvastatin). MATERIALS AND METHODS: Eighteen male animals (3-4 months old) were divided into 3 groups. Group 1 consisted of control animals receiving a normal chow diet, Group 2 animals received a high fat (12% w/w) and low cholesterol (0.1% w/w) diet (HFLCD), and Group 3 animals received HFLCD+statin for 12 weeks. Animals received statin at 3 mg/kg body weight per day. HFLCD did not down-regulate the hepatic expression of HMGCR mRNA. RESULTS: HFLCD increased body, omentum, and mesenteric adipose tissue weight, and induced hypercholesterolemia and atherosclerotic lesions in the abdominal aorta. HFLCD+statin inhibited hypercholesterolemia and atherosclerotic lesions, but not obesity. CONCLUSION: A microminipig atherosclerosis model induced by HFLCD can be used in the evaluation of HMGCR inhibitors for the treatment of hypercholesterolemia and atherosclerosis.

Hypoxia-Mediated Long Non-Coding RNA Fragment Identified in Canine Oral Melanoma through Transcriptome Analysis.

Hypoxia contributes to tumor progression and metastasis, and hypoxically dysregulated RNA molecules may, thus, be implicated in poor outcomes. Canine oral melanoma (COM) has a particularly poor prognosis, and some hypoxia-mediated miRNAs are known to exist in this cancer; however, equivalent data on other hypoxically dysregulated non-coding RNAs (ncRNAs) are lacking. Accordingly, we aimed to elucidate non-miRNA ncRNAs that may be mediated by hypoxia, targeting primary-site and metastatic COM cell lines and clinical COM tissue samples in next-generation sequencing (NGS), with subsequent qPCR validation and quantification in COM primary and metastatic cells and plasma and extracellular vesicles (EVs) for any identified ncRNA of interest. The findings suggest that a number of non-miRNA ncRNA species are hypoxically up- or downregulated in COM. We identified one ncRNA, the long ncRNA fragment ENSCAFT00000084705.1, as a molecule of interest due to its consistent downregulation in COM tissues, hypoxically and normoxically cultured primary and metastatic cell lines, when compared to the oral tissues from healthy dogs. However, this molecule was undetectable in plasma and plasma EVs, suggesting that its expression may be tumor tissue-specific, and it has little potential as a biomarker. Here, we provide evidence of hypoxic transcriptional dysregulation for ncRNAs other than miRNA in COM for the first time and suggest that ncRNA ENSCAFT00000084705.1 is a molecule of interest for future research on the role of the transcriptome in the hypoxia-mediated progression of this aggressive cancer.

Elevated expression of miR-301a and its functional roles in canine oral melanoma.

miR-301a is one of numerous dysregulated microRNAs (miRNAs) in canine oral melanoma (COM), one of which is miR-301a (upregulated). Its biological role has been described in various human cancer types, including malignant melanoma, but not in COM. Accordingly, in this study, we investigated miR-301a expression in COM in greater detail to ascertain whether it could serve as a diagnostic biomarker, elucidate its functional roles in this cancer, and predict the possible pathways by which it exerts its effects. Relative expression of miR-301a was investigated in clinical oral tissue and plasma samples and COM cell (KMeC and LMeC) lines using qRT-PCR. Knockdown of miR-301a was also validated for KMeC and LMeC cells using qRT-PCR. We performed CCK-8 assays to assess cell proliferation, monolayer wound-healing, and transwell migration assays to assess cell migration, a colony-formation assay to assess clonogenicity, a TUNEL assay and flow cytometry to assess apoptosis-related effects, and gene enrichment analyses to predict possible related pathways. miR-301a was markedly upregulated in COM oral tissue and plasma clinically, suggesting its potential as a diagnostic biomarker for COM diagnosis. In vitro assays demonstrated that miR-301 significantly inhibited apoptosis in COM cells while promoting cell migration, proliferation, and clonogenicity. We also predicted that miR-301 exerts cancer-promoting effects through the Wnt signalling pathway for COM. Our findings suggest that miR-301a is a COM oncomiR that regulates several oncogenic phenotypes with the potential to be a diagnostic biomarker.

Upregulation and functional roles of miR-450b in canine oral melanoma.

Canine oral melanoma (COM) is a common and highly aggressive disease with the potential to model human melanomas. Dysregulated microRNAs represent an interesting line of research for COM because they are implicated in tumor progression. One example is miR-450b, which has been investigated for its molecular mechanisms and biological functions in multiple human cancers, but not human or canine melanoma. Here, we aimed to investigate miR-450b as a potential diagnostic biomarker of COM and its functional roles in metastatic and non-metastatic forms of the disease. We investigated the expression of miR-450b and its target mRNA genes in clinical (tumor tissue and plasma) samples and metastatic and primary-tumor cell lines. Knockdown and overexpression experiments were performed to determine the influence of miR-450b on cell proliferation, migration, colony formation, and apoptosis. miR-450b was significantly upregulated in COM and differentiated between metastatic and non-metastatic tumors, and its potential as a biomarker of metastatic and non-metastatic COM was further confirmed in ROC analysis. miR-450b knockdown promoted cell proliferation, migration, and clonogenicity and inhibited apoptosis, whereas its overexpression yielded the reverse pattern. miR-450b directly binds 3' UTR of PAX9 mRNA and modulates its function leading to BMP4 downregulation and MMP9 upregulation at the transcript level. Furthermore, we surmised that miR-450b activates the Wnt signaling pathway based on gene ontology and enrichment analyses. We concluded that miR-450b has the potential as a diagnostic biomarker and could be a target candidate for COM treatment.

Aberrantly Expressed tRNA-Val Fragments Can Distinguish Canine Hepatocellular Carcinoma from Canine Hepatocellular Adenoma.

Hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC) can be difficult to differentiate but must be diagnosed correctly as treatment and prognosis for these tumors differ markedly. Relevant diagnostic biomarkers are thus needed, and those identified in dogs may have utility in human medicine because of the similarities between human and canine HCA and HCC. A tRNA-derived fragment (tRF), tRNA-Val, is a promising potential biomarker for canine mammary gland tumors but has not previously been investigated in hepatic tumors. Accordingly, we aimed to elucidate the potential utility of tRNA-Val as a biomarker for canine HCA and HCC using clinical samples (tumor tissue and plasma extracellular vesicles [EVs]) and tumor cell lines with qRT-PCR assays. We also investigated relevant functions and signaling pathways with bioinformatic analyses (Gene Ontology and Kyoto Encyclopedia of Genes and Genomes). tRNA-Val was markedly downregulated in HCC tumor tissue versus HCA tumor tissue and normal liver tissue, and a similar trend was shown in plasma EVs and HCC cell lines versus healthy controls. Based on areas under the receiver operating characteristic curves (AUCs), tRNA-Val significantly distinguished HCC (AUC = 1.00, p = 0.001) from healthy controls in plasma EVs and HCC from HCA (AUC = 0.950, p = 0.01). Bioinformatics analysis revealed that tRNA-Val may be primarily involved in DNA repair, mRNA processing, and splicing and may be linked to the N-glycan and ubiquitin-mediated proteasome pathways. This is the first report on the expression of tRNA-Val in canine HCC and HCA and its possible functions and signaling pathways. We suggest that tRNA-Val could be a promising novel biomarker to distinguish canine HCC from HCA. This study provides evidence for a greater understanding of the role played by tRNA-Val in the development of canine HCC.

A dermal phototoxicity study following intravenous infusion administration of ciprofloxacin hydrochloride in the novel microminipigs.

The authors evaluated dermal phototoxicity using the world smallest minipig (MMPig: Microminipig). MMPigs were administered 100 mg/kg ciprofloxacin hydrochloride with an infusion pump. The dorsal area of each animal was irradiated with ultraviolet-A irradiation. The left dorsal skin was irradiated at intensities of 5, 10, 15, and 20 J/cm(2), and the right dorsal back skin was set as a nonirradiated site. Gross and histopathological examinations were conducted before irradiation and from 1 to 72 hr after irradiation. Initial changes in the skin were necrosis of the basal and/or prickle cell layer and cellular infiltration from 24 hr after irradiation. Vesicle formation observed from 48 hr after irradiation was considered similar to bullous eruptions, a known side effect of fluoroquinolones in humans. Therefore, the authors suggest that the MMPig may be a useful experimental animal model for dermal phototoxicity studies.

Good relationship between saliva cotinine kinetics and plasma cotinine kinetics after smoking one cigarette.

This study investigated the relationship between plasma and saliva cotinine kinetics after smoking one cigarette and the relationship between cotinine kinetics and estimated nicotine intake, which was calculated as mouth level exposure (MLE) of nicotine, from smoking two test cigarettes with different nicotine yields. This study was conducted in 16 healthy adult Japanese smokers, who did not have null nor reduced-activity alleles of CYP2A6, with a quasi-randomized crossover design of smoking a low-tar cigarette or a high-tar cigarette. Saliva cotinine showed similar concentration profiles to plasma cotinine, and all of the calculated pharmacokinetic parameters of cotinine showed the same values in plasma and saliva. The Cmax and AUC of cotinine showed almost the same dose-responsiveness to the estimated MLE of nicotine between plasma and saliva, but the tmax and t1/2 of cotinine were not affected by the estimated MLE of nicotine in either plasma or saliva. The results show that saliva cotinine kinetics reflects plasma cotinine kinetics, and measurement of saliva cotinine concentration gives the same information as plasma cotinine on the nicotine intake. Thus, saliva cotinine would be a good and less-invasive exposure marker of cigarette smoke, reflecting the plasma cotinine concentration and kinetics.