Trophic niche partitioning and intraspecific variation in food resource use in the genus Pangasianodon in a reservoir revealed by stable isotope analysis of multiple tissues.

Understanding the mechanism by which non-native fish species integrate into native communities is crucial for evaluating the possibility of their establishment success. The genus Pangasianodon, comprising Pangasianodon gigas and Pangasianodon hypophthalmus, has been introduced into reservoirs, which are non-native habitats, for fishery stock enhancement. P. gigas and P. hypophthalmus often successfully establish and co-occur in several Thai reservoirs, but there is little information on differences in food resource use between the two species. To investigate the trophic niche width of P. gigas and P. hypophthalmus in a Thai reservoir, we conducted stable carbon and nitrogen ratio (δ13C and δ15N) analyses. We examined the degree of individual specialization in both species using the δ13C and δ15N values of muscle and liver tissues, which provides long- and short-term diet information. The isotopic niches did not overlap between P. gigas and P. hypophthalmus. The δ15N value of P. gigas was significantly higher than that of P. hypophthalmus, whereas the δ13C value did not significantly differ between the two species. The isotopic niche sizes were larger in P. hypophthalmus than in P. gigas. Individual specialization was observed in P. hypophthalmus but not in P. gigas, indicating that intraspecific variation in food resource use was larger in P. hypophthalmus compared to P. gigas. These findings suggest that trophic niche partitioning was one of the factors facilitating the establishment success of P. gigas and P. hypophthalmus in a reservoir, but the establishment process may differ between the two species.

Striped catfish (Pangasianodon hypophthalmus) exploit food sources across anaerobic decomposition- and primary photosynthetic production-based food chains.

Dietary information from aquatic organisms is instrumental in predicting biological interactions and understanding ecosystem functionality. In freshwater habitats, generalist fish species can access a diverse array of food sources from multiple food chains. These may include primary photosynthetic production and detritus derived from both oxic and anoxic decomposition. However, the exploitation of anoxic decomposition products by fish remains insufficiently explored. This study examines feeding habits of striped catfish (Pangasianodon hypophthalmus) at both adult and juvenile stages within a tropical reservoir, using stable carbon, nitrogen, and sulfur isotope ratios (δ13C, δ15N, and δ34S, respectively) and fatty acid (FA) analyses. The adult catfish exhibited higher δ15N values compared to primary consumers that feed on primary photosynthetic producers, which suggests ingestion of food sources originating from primary photosynthetic production-based food chains. On the other hand, juvenile catfish demonstrated lower δ15N values than primary consumers, correlating with low δ34S value and large proportions of bacterial FA but contained small proportions of polyunsaturated FA. This implies that juveniles utilize food sources from both anoxic decomposition and primary photosynthetic production-based food chains. Our results indicate that food chains based on anoxic decomposition can indeed contribute to the dietary sources of tropical fish species.

HSD17B4 methylation enhances glucose dependence of BT-474 breast cancer cells and increases lapatinib sensitivity.

PURPOSE: HER2-positive breast cancer has a high chance of achieving pathological complete response when HSD17B4, responsible for peroxisomal ß-oxidation of very long-chain fatty acids (VLCFA) and estradiol, is methylation-silenced. Here, we aimed to identify the underlying molecular mechanism. METHODS: Using a HER2-positive breast cancer cell line, BT-474, control and knock-out (KO) clones were obtained. Metabolic characteristics were analyzed using a Seahorse Flux analyzer. RESULTS: HSD17B4 KO suppressed cellular proliferation, and enhanced sensitivity to lapatinib approximately tenfold. The KO led to accumulation of VLCFA and a decrease of polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA) and arachidonic acid. HSD17B4 KO increased Akt phosphorylation, possibly via decreased DHA, and genes involved in oxidative phosphorylation (OxPhos) and electron transport chain (ETC) were upregulated. Increased mitochondrial ATP production in the KO cells was confirmed by extracellular flux analyzer. Increased OxPhos led to severe dependence of the KO cells on pyruvate from glycolysis. Suppression of glycolysis by lapatinib led to severe delayed suppression of OxPhos in KO cells. CONCLUSION: HSD17B4 KO in BT-474 cells caused a decrease of PUFAs, increased Akt phosphorylation, enhanced glucose dependence of OxPhos, and increased sensitivity to inhibition of HER2, upstream of Akt. This mechanism may be applicable to other HER2-positive glucose-dependent breast cancer cells with HSD17B4 silencing.

Cytological characteristics of histological types of lung cancer by cytomorphometric and flow cytometric analyses using liquid-based cytology materials.

BACKGROUND: Distinguishing the histological types of lung cancer is essential for determining treatment strategies in clinical practice. In this study, cytomorphological characteristics and proliferative activities were compared among histological types of lung cancer by cytomorphometric and flow cytometric analyses using liquid-based cytology (LBC) samples. METHODS: Scraped LBC samples from 73 surgically resected specimens were collected between August 2018 and November 2019. Papanicolaou-stained and paired Ki-67-stained slides were used for cytomorphometric analyses. Another sample for each case was analyzed using a flow cytometric system (LC-1000). The cell proliferation index (CPIx) was calculated to evaluate proliferative activity. RESULTS: In total, 73 cases, including cases of adenocarcinoma (n = 53), squamous cell carcinoma (n = 14), small cell carcinoma (n = 1), large cell neuroendocrine carcinoma (NEC; n = 3), and pleomorphic carcinoma (n = 2) were evaluated. Small cell carcinoma and large cell NEC were categorized into a single group, NEC. The adenocarcinoma group tended to have a larger nuclear area and longer perimeter than other histological types. The NEC group had a considerably higher Ki-67 labeling index and significantly higher CPIx than other histological types (p = .030). A significant positive correlation was observed between the Ki-67 labeling index and CPIx for all cases (r = 0.362, p = .002). CONCLUSION: The Ki-67 labeling index and flow cytometric analyses focus on proliferative activity for the distinction of histological types of lung cancer, thereby guiding clinical decision-making.

Trajectory to local extinction of an isolated dugong population near Okinawa Island, Japan.

A small animal population becomes extinct owing to demographic and environmental stochasticity after declining below the minimum viable population (MVP). However, the actual process of extinction derived by stochastic factors after crossing MVP has not been recorded for long-lived marine mammals. Here, we reconstructed the declining history of a small, isolated population of dugongs in Okinawa over 125 years. The initial population size of approximately 280-420 in the nineteenth century declined to approximately < 100 in 1917 because of overfishing, < 70 in 1979, 11 in 1997, 3 after 2006, and all known individuals disappeared or died by 2019. After 1979, a decline in the natural growth rate has led to extinction. Long-lived animals may persist for a few decades after the population falls below the MVP, at which time active conservation measures, such as captive breeding, should be implemented.

Optimal Preservations of Cytological Materials Using Liquid-Based Cytology Fixatives for Next-Generation Sequencing Analysis.

INTRODUCTION: Molecular targeted therapies have been established for various diseases, including cancers, and there is an increasing need for molecular testing on cytology specimens. The aim of this study was to determine the optimal preservation methods of liquid-based cytology (LBC) materials for molecular testing. METHODS: Cytological samples from 35 surgical resected non-small cell lung carcinoma specimens were obtained between June 2016 and June 2021. The samples were fixed in CytoRich™ red Preservative and stored at 4°C. One week later, three tubes were prepared from each specimen sample and divided into the following groups: the SurePath™ group (continued storage at 4°C), Frozen (Fr) group (stored at -80°C after centrifugation), and LBC-Cell Block (LBC-CB) group (generation of paraffin-embedded CB and storage at 4°C). Samples from 5 patients were used for the time course analysis, and we performed evaluations on these samples at 1, 3, 6, 12, 24, and 36 months. The concentrations and purities of extracted DNA and RNA were measured. The double-stranded DNA (dsDNA) and RNA concentrations were also measured by a fluorometer. The DNA and RNA integrities were quantified by the DNA and RNA integrity number. RESULTS: Evaluation of samples was performed at baseline and the six timepoints. In the LBC-CB group, DNA and dsDNA concentrations were higher rather than those in the other groups. The RNA concentration of the LBC-CB group was relatively high compared with those of the other groups at the 36-month timepoint. The Fr group maintained higher DNA quality compared with the other groups over 3 years. The LBC-CB group maintained a higher RNA quality than the other groups until 24 months. CONCLUSION: LBC-CB preparation is an effective method to maintain DNA/RNA quality and quantity in long-duration preservation for eventual molecular testing. Therefore, LBC-CB may have applications on preanalytical stage for molecular genomic testing such as next-generation sequencing.

Factors associated with canine skin extensibility in toy poodles.

To assess factors for canine skin extensibility, our study investigated associations between the dogs' skin extension index and the following factors, gender, age, neuter status, weight, coat color and six coat color related gene polymorphisms. Swab samples were collected from 69 toy poodles to extract DNA. The skin extension indices of the lower back and the neck were measured using the following formula: vertical height of the skin fold divided by body length multiplied by 100. The dogs' age, weight, gender, neuter status and coat color were also recorded, as well as polymorphisms of the following six selected coat color related genes, Melanocortin 1 receptor, Tyrosinase-related protein 1, Melanophilin, Canine ß-defensin-1, Major Facilitator Superfamily Domain Containing 12 and Agouti-signaling protein (ASIP). Univariable analysis showed there was a meaningful association between the lower back skin extension index and both gender and age (P<0.001 and P=0.048, respectively). Also, there was a possible association between the lower back skin extension index and ASIP Single nucleotide polymorphism (SNP) (R96C) (P=0.078). Linear model analysis showed there was a significant association between the lower back skin extension index and gender (P<0.001), and there was a tendency of the association between the lower back skin extension index and ASIP SNP (R96C) (P=0.098). In addition, there was an association between gender and age for the skin extension index. (P=0.048). Therefore, these results suggest that a greater risk of skin extensibility in toy poodle could be related to being female and the ASIP SNP (R96C), because these factors were associated with higher lower back skin extension index.

Deep neural networks based automated extraction of dugong feeding trails from UAV images in the intertidal seagrass beds.

Dugongs (Dugong dugon) are seagrass specialists distributed in shallow coastal waters in tropical and subtropical seas. The area and distribution of the dugongs' feeding trails, which are unvegetated winding tracks left after feeding, have been used as an indicator of their feeding ground utilization. However, current ground-based measurements of these trails require a large amount of time and effort. Here, we developed effective methods to observe the dugongs' feeding trails using unmanned aerial vehicle (UAV) images (1) by extracting the dugong feeding trails using deep neural networks. Furthermore, we demonstrated two applications as follows; (2) extraction of the daily new feeding trails with deep neural networks and (3) estimation the direction of the feeding trails. We obtained aerial photographs from the intertidal seagrass bed at Talibong Island, Trang Province, Thailand. The F1 scores, which are a measure of binary classification model's accuracy taking false positives and false negatives into account, for the method (1) were 89.5% and 87.7% for the images with ground sampling resolutions of 1 cm/pixel and 0.5 cm/pixel, respectively, while the F1 score for the method (2) was 61.9%. The F1 score for the method (1) was high enough to perform scientific studies on the dugong. However, the method (2) should be improved, and there remains a need for manual correction. The mean area of the extracted daily new feeding trails from September 12-27, 2019, was 187.8 m2 per day (n = 9). Total 63.9% of the feeding trails was estimated to have direction within a range of 112.5° and 157.5°. These proposed new methods will reduce the time and efforts required for future feeding trail observations and contribute to future assessments of the dugongs' seagrass habitat use.

Pneumomediastinum while using mechanical insufflation-exsufflation after recovery from riluzole-induced interstitial lung disease.

We, herein, report a 61-year-old male patient with amyotrophic lateral sclerosis (ALS) complicated pneumomediastinum while using mechanical insufflation-exsufflation (MI-E) after recovery from riluzole (RZ)-induced interstitial lung disease (RZ-ILD). After the treatment of RZ-ILD, he required non-invasive mechanical ventilation (NIV) at minimal pressure settings and MI-E to manage ALS-related breathing and airway-clearance issues, respectively. After a while, he developed progressive worsening dyspnoea, and chest computed tomography revealed extensive pneumomediastinum that had spread to the area surrounding the oesophagus, the retrosternal space, and the pericardial space. He was treated with immediate discontinuation of MI-E; however, he had to keep using NIV to support his severe respiratory muscle involvement. Pneumomediastinum gradually reduced in size and no recurrence of pneumomediastinum occurred. The clinical course of our patient suggests that excessive coughing associated with MI-E combined with his previous RZ-ILD, which potentially renders his lungs vulnerable to airway pressure, may have been the aetiological factors for secondary pneumomediastinum, i.e. barotrauma. Clinicians should be aware of the risk of pneumomediastinum while using MI-E in patients with ALS, who have other pre-existing risk factors for pneumomediastinum, such as drug-induced ILD in our case.

Migration, residency and habitat utilisation by wild and cultured Japanese eels (Anguilla japonica) in a shallow brackish lagoon and inflowing rivers using acoustic telemetry.

This study monitored post-release movements of 20 wild Japanese eels (Anguilla japonica) [mean ± S.D. 520.8 ± 92.3 mm total length (TL), 217.9 ± 146.3 g body mass (BM)] in a brackish water lagoon in northeastern Japan using acoustic telemetry to elucidate how wild Japanese eels use different river, estuary and marine environments. In addition, 12 cultured Japanese eels (TL = 578.9 ± 18.0 mm, BM = 344.9 ± 25.5 g) were released to understand the comparative behaviours of wild and cultured eels. Both types of eels were simultaneously released in the southern inner part of the lagoon in September 2016 where there are freshwater influences from a river. Following release, eight of the wild eels (40%) were largely sedentary near the released point (river mouth) and stayed at the site for overwinter. Nonetheless, several individuals showed behavioural plasticity of habitat use: three wild eels moved towards the northern part of the lagoon with stronger influence from the sea during May-July 2017. Two wild eels showed clear repeated movements from the lagoon to a river at night and returned to the lagoon by dawn for more than a week every day, and one wild eel migrated upstream for overwintering. Signals from 55% of the wild eels could be detected for more than 6 months, whereas those from all of the cultured eels were lost by December 2016, indicating a short resident time of large cultured eels (BM > 200 g) released in a brackish water area. One wild silver eel migrated to the outer sea during the ebb tide at night in November 2016, probably triggered by the decrease in water temperature (from c. 20°C to c. 13°C), and seven cultured eels similarly moved to the outer sea during October-November 2016. The results revealed the similarities (e.g., nocturnal movements) and differences (e.g., stay period and seasonal movements) in the behavioural characteristics of wild and cultured eels and indicated that habitat connectivity among river, estuary and coastal waters is crucial for enabling eels to efficiently utilise these productive habitats through their behavioural plasticity.

Gut Morphometry Represents Diet Preference to Indigestible Materials in the Largest Freshwater Fish, Mekong Giant Catfish (Pangasianodon gigas).

The Mekong giant catfish Pangasianodon gigas is one of the largest freshwater fish, measuring up to 3 m in total length. This study was designed to determine the feeding habits of P. gigas to better understand how the fish achieve their large body size. We compared the relationship between gut length (GL) and total length (TL) among related species in superfamily Bagroidea, order Siluriformes (Pangasianodon hypophthalmus and Hemibagrus nemurus) in the Kaeng Krachan reservoir, Thailand. The mean relative gut length (RGL = GL / TL) of P. gigas was 3.50, showing that they have relatively long guts, with values more similar to those of omnivorous P. hypophthalmus (RGL = 3.70) than to those of carnivorous H. nemurus (RGL = 0.92). In the allometric relationship (i.e., log10 GL = log10 a + b log10 TL), the slope close to 1 for P. gigas (b = 1.07) has been widely observed in carnivores, while P. gigas has a greater intercept of the linear equation than P. hypophthalmus and H. nemurus, resulting in a similar GL of P. gigas to omnivorous P. hypophthalmus at approximately 35 cm in TL. Moreover, GL of P. gigas at 150 to 250 cm in TL showed great variations (RGL = 1.35-6.32). The variation in RGL for P. gigas seemed to result from a poor nutritional state. In conclusion, P. gigas is suggested to feed on indigestible materials such as plants, algae, and sediments, and potentially experience fasting in a reservoir.

Multi-omics analyses identify HSD17B4 methylation-silencing as a predictive and response marker of HER2-positive breast cancer to HER2-directed therapy.

HER2-positive breast cancers that achieve pathological complete response (pCR) after HER2-directed therapy consistently have good survival. We previously identified HSD17B4 methylation as a marker for pCR by methylation screening. Here, we aimed to identify a new marker by conducting a multi-omics analysis of materials prepared by laser capture microdissection, and adding 71 new samples. In the screening set (n = 36), mutations, methylation, and expression were analyzed by targeted sequencing, Infinium 450 K, and expression microarray, respectively, and 15 genes were identified as differentially expressed and eight genomic regions as differentially methylated between cancer samples with and without pCR. In a validation set (n = 47), one gene showed differential expression, and one region had differential methylation. Further, in the re-validation set (n = 55), all new samples, only HSD17B4 methylation was significantly different. The HSD17B4 methylation was at the transcriptional start site of its major variant, and was associated with its silencing. HSD17B4 was highly expressed in the vast majority of human cancers, and its methylation was present only in breast cancers and one lymphoblastic leukemia cell line. A combination of estrogen receptor-negative status and HSD17B4 methylation showed a positive predictive value of 80.0%. During HER2-directed neoadjuvant therapy, HSD17B4 methylation was the most reliable marker to monitor response to the therapy. These results showed that HSD17B4 methylation is a candidate predictive and response marker of HER2-positive breast cancer to HER2-directed therapy.

Author Correction: Inhibition of Porphyromonas gulae and periodontal disease in dogs by a combination of clindamycin and interferon alpha.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Subtyping and EGFR mutation testing from blocks of cytological materials, based on liquid-based cytology for lung cancer at bronchoscopic examinations.

BACKGROUND: Liquid-based cytology (LBC) allows immunohistochemistry (IHC), fluorescence in situ hybridization, and molecular testing to be performed in fixed cell materials. We examined the feasibility of subtyping and EGFR mutation testing of bronchoscopic samples from patients with lung cancer using cell blocks (CB) based on LBC fixation (LBC-CB). METHODS: We included 35 consecutive patients with peripheral lung nodules who underwent endobronchial ultrasonography with a guide sheath in our hospital. Thirty of these patients were diagnosed with lung cancer by obtaining cytological samples. Cytological subtyping was performed with IHC using LBC-CB, and the Cobas EGFR Mutation Test ver. 2 was performed using extracted genomic DNA from the LBC-CB, formalin-fixed paraffin-embedded (FFPE) tissue, and matched plasma. RESULTS: Of the 30 cases, 25 were classified cytomorphologically as adenocarcinoma (ADC, n = 17) and squamous-cell carcinoma (SQCC, n = 8). The remaining five cases were classified by IHC as favor ADC (n = 3) and favor SQCC (n = 2) according to the WHO criteria. In the final ADC group (n = 20), EGFR mutations on the LBC-CB were identified in eight cases (40%; 1 exon 19 deletion, 6 L858R, and 1 L861Q). Mutations in FFPE samples were identified in seven cases (35%) at the same site in each case. Plasma EGFR mutations were identified in four cases (20%) at the same site. The CB detection rate was higher than for FFPE and plasma. CONCLUSION: LBC-CB is suitable for subtyping and EGFR mutation testing in lung cancers.

Inhibition of Porphyromonas gulae and periodontal disease in dogs by a combination of clindamycin and interferon alpha.

Porphyromonas gulae is a major periodontal pathogen in dogs, which can be transmitted to their owners. A major virulence factor of P. gulae consists of a 41-kDa filamentous appendage (FimA) on the cell surface, which is classified into three genotypes: A, B, and C. Thus far, inhibition of periodontal disease in dogs remains difficult. The present study assessed the inhibitory effects of a combination of clindamycin and interferon alpha (IFN-α) formulation against P. gulae and periodontal disease. Growth of P. gulae was significantly inhibited by clindamycin; this inhibition had a greater effect on type C P. gulae than on type A and B isolates. In contrast, the IFN-α formulation inhibited the expression of IL-1ß and COX-2 elicited by type A and B isolates, but not that elicited by type C isolates. Furthermore, periodontal recovery was promoted by the administration of both clindamycin and IFN-α formulation to dogs undergoing periodontal treatment; moreover, this combined treatment reduced the number of FimA genotypes in oral specimens from treated dogs. These results suggest that a combination of clindamycin and IFN-α formulation inhibit P. gulae virulence and thus may be effective for the prevention of periodontal disease induced by P. gulae.

A rare post-lobectomy complication of right-to-left shunt via foramen ovale.

BACKGROUND: Various complications can cause hypoxemia after pulmonary resection for lung cancer, but intracardiac shunt that becomes symptomatic and causes severe hypoxemia postoperatively is very rare. We report a case that presented platypnea-orthodeoxia syndrome (POS) due to right-to-left shunt via patent foramen ovale (PFO). CASE: A 71-year-old man with a lung cancer in the left upper lobe was referred to our hospital. Left upper lobectomy was performed. Dyspnea developed postoperatively, which was worsened by sitting or standing and relieved in a recumbent position. Contrast transesophageal echocardiogram (TEE) and right intracardiac catheterization revealed a right-to-left shunt via PFO. Open-heart closure of PFO was performed and the patient was free from POS. CONCLUSIONS: Postoperative intracardiac shunt via PFO can cause severe hypoxemia after lung resection. POS suggests the possibility of intracardiac shunt and careful observation is needed.

Perioperative Atrial Fibrillation in Noncardiac Surgeries for Malignancies and One-Year Recurrence.

BACKGROUND: Perioperative atrial fibrillation (POAF) in noncardiac surgeries is common. However, it is unclear whether such atrial fibrillation (AF) recurs in the long term. METHODS: This study was a prospective, single-center, observational study that included patients who underwent noncardiac surgeries for malignancies. Patients were followed up for 1 year to evaluate the incidence of AF, ischemic stroke, and mortality. An event-triggered recorder was used in patients with POAF. The incidences were compared according to the presence of POAF. RESULTS: Of 752 consecutive patients, 77 (10.2%) developed POAF and wore an event recorder for 19 (12-30) days. AF and ischemic stroke at 1 year were observed in 24 patients (31.1%) and 2 patients (2.6%) with POAF and 4 patients (0.6%) and 3 patients (0.4%) without POAF, respectively. Of the 24 patients with POAF and AF recurrence, 22 (92%) were asymptomatic. Anticoagulation was prescribed in 67 patients (87%) with POAF. Multivariate Cox regression analysis demonstrated that a higher AF recurrence rate in patients with POAF was associated with hypertension (hazard ratio, 2.79; 95% confidence interval, 1.06-7.38) and serum creatinine level (hazard ratio for 20 µmol/L increase, 2.32; 95% confidence interval, 1.16-4.62). CONCLUSIONS: AF recurs in approximately 30% of patients with POAF with malignancy in the subsequent year; most recurrences are asymptomatic.

Incidence and complications of perioperative atrial fibrillation after non-cardiac surgery for malignancy.

BACKGROUND: Perioperative atrial fibrillation (POAF) is one of the common arrhythmias in the setting of non-cardiac surgeries for malignancy. As POAF may cause subsequent adverse events, it is important to confirm its characteristics and risk factors. MATERIALS AND METHODS: The prospective cohort study of surveillance for perioperative atrial fibrillation recurrence (PREDICT AF RECURRENCE) is an ongoing prospective, single-center, observational study that aims to illustrate the clinical impact of POAF in major non-cardiac surgery for malignancy. Patients who planned to undergo non-cardiac surgery for definitive/suspected malignancy were registered. Those with a history of AF and atrial flutter were excluded. Any 30-day complications included acute myocardial infarction, congestive heart failure, bleeding, thrombosis, any infection, and acute kidney injury. The primary endpoint was an incidence of POAF. RESULTS: The present study included 799 patients (age, 68 ± 11; male, 62%). Of these, 80 patients (10.0%) developed POAF. Notably, 66 patients (83%) had no symptoms. Any 30-day complications occurred in 180 patients (23%) (with POAF: 34 (43%); without POAF: 146 (20%); p < 0.001). POAF in 17 patients (50%) was preceded by the development of complications. No patient developed cardiogenic shock and/or acute heart failure. The association between 30-day complications and POAF development were analyzed using the multivariate adjusted model (odds ratio: 2.84; 95% confidence interval: 1.74-4.62; p < 0.001). CONCLUSION: Ten percent of patients who underwent non-cardiac surgery for malignancy developed POAF, which was strongly associated with perioperative complications. As a majority were asymptomatic, careful observation using electrocardiography monitoring is important to avoid oversights. CLINICAL TRIAL REGISTRATION: UMIN ID: UMIN000016146.

Identification and molecular characterization of Porphyromonas gulae fimA types among cat isolates.

Porphyromonas gulae, a Gram-negative black-pigmented anaerobe, is one of several major periodontal pathogens of animals. P. gulae isolates from dogs have been classified into three genotypes based on a 41-kDa filamentous appendage (FimA) on the cell surface, which is closely related to virulence in periodontal disease. However, other specific bacterial virulence factors contributing to the aggravation of periodontal disease in cats remain elusive. In the present study, we assessed FimA diversity in P. gulae isolates from cats and examined whether this diversity influenced periodontal condition. The putative amino acid sequences of FimA from 15 P. gulae isolates from 13 cats were classified into three genotypes (types A, B, and C), which showed 95-100% identity and similarity to the fimA types in dogs. The type C isolate showed greater adhesion and invasion properties in periodontal ligament fibroblasts as well as stronger inhibition of scratch closure of the cells compared with type A and B isolates. Next, a PCR-based method for identification of fimA genotype was developed and used to analyze 99 oral swab specimens from cats. High fimA type A detection rates were observed regardless of the periodontal condition, whereas types B and C were frequently detected from subjects with moderate and severe periodontitis, respectively. These results suggest that P. gulae isolates from cats can be classified into three types based on fimA genotype, which may be closely related to virulence in periodontitis.

Simultaneous observation of intermittent locomotion of multiple fish by fine-scale spatiotemporal three-dimensional positioning.

Recent advances in biotelemetry techniques, especially positioning methods, have revealed the detailed behaviour and movement of aquatic organisms. Behavioural intermittence in animal locomotion, such as the Lévy walk, is a popular topic in the field of movement ecology. Previous attempts to describe intermittent locomotion quantitatively have been constrained by the spatial and temporal resolution possible with conventional biotelemetry systems. This study developed a fine-scale spatiotemporal three-dimensional positioning method using a new biotelemetry system with a positional precision of <10 cm and positioning interval of <10 s. Using this proposed positioning method, the intermittent stop-and-go locomotion of Siebold's wrasses (Pseudolabrus sieboldi) was observed during travel from an unsuitable to a suitable location following displacement. The fish displayed behavioural intermittence in relocating to a suitable location. Initially, their movement halted for reorientation, after which they moved intermittently yet in a straight line to the suitable location. To test the positioning ability of the proposed method, data sets were resampled at intervals of 5, 10, 30, 60, and 300 s. Longer sampling intervals failed to identify reorientations and underestimated the number of stops, distance travelled, and speed. Overall, the results highlighted the adequacy and ability of the proposed positioning method to observe the intermittent locomotion of fish, such as stop-and-go behaviour, in a natural environment.