Dimensional changes over time in stereolithographic models fabricated with a 3D printer.

This study aimed to ascertain the effects of the shape of stereolithographic models fabricated with a three-dimensional (3D) printer and the use of different types of liquid resin on the dimensional changes of these models over time, to obtain valuable information for determining the period for which such models can be used following fabrication. Stereolithography models with the shape of a large truncated cone or a small truncated cone were fabricated using liquid resin as surgical guides (Group G) or master casts (Group M). (four groups in total, each n = 11). The shapes of all experimental specimens were measured immediately after fabrication and 1 day, 1 week, 2 weeks, 3 weeks, 4 weeks, 2 months, 3 months, 6 months, 1 year, and 1.5 years later. The shape data collected immediately after fabrication were taken as baseline data, and the dimensional changes over time at each timepoint were calculated. No significant change from 1 day to 1 year after fabrication was observed in any of the groups, but the change after 1.5 years was significantly larger than the changes at the other timepoints (p < 0.001). Significantly larger changes were evident in Group M than in Group G at all timepoints (p < 0.001). These results suggested that, from the viewpoint of dimensional stability over time, stereolithographic models should be used within 1 year of fabrication, and that the type of liquid resin used for stereolithographic model fabrication may affect how its dimensions change over time.

Resection of chronic expanding hematoma within the liver cyst difficult to differentiate from liver cystadenocarcinoma: A case report.

Liver cysts are common benign lesions with rare malignancy potential. Distinguishing between benign and malignant tumors within liver cysts is challenging. We present the case of a patient with a chronically expanding hematoma within a liver cyst that was resected under suspicion of liver cystadenocarcinoma. A 73-year-old female patient presented with elevated hepatobiliary enzyme levels, no viral hepatitis, elevated tumor marker levels, and preserved liver capacity (Child-Pugh grade A). Abdominal ultrasonography revealed a large cyst (>10 cm) occupying the right lobe and a 25-mm mass lesion with mixed echogenicity inside the cyst. Contrast-enhanced computed tomography showed atrophy of the parenchyma of the right lobe and dilation of the right intrahepatic bile duct due to the large cyst. Moreover, in the arterial phase, a point-like high-density area was observed inside the nodule, which increased from 25 to 35 mm over 3 months. Diffusion-weighted magnetic resonance imaging revealed a high-intensity signal within the nodule; however, positron emission tomography did not show an increased accumulation of fluorodeoxyglucose in the same area. Considering the risk of peritoneal dissemination if the cyst was punctured and found to be malignant, we performed a right hepatectomy. Pathological findings revealed a brownish fluid-filled cyst containing a dark reddish nodule diffusely filled with hematoma, confirming the absence of a malignancy. To date, the patient has not experienced recurrence. We encountered a case of a chronic, expanding hematoma originating from a liver cyst that was difficult to distinguish preoperatively from a liver cystadenocarcinoma.

The gut microbiota-induced kynurenic acid recruits GPR35-positive macrophages to promote experimental encephalitis.

The intricate interplay between gut microbes and the onset of experimental autoimmune encephalomyelitis (EAE) remains poorly understood. Here, we uncover remarkable similarities between CD4+ T cells in the spinal cord and their counterparts in the small intestine. Furthermore, we unveil a synergistic relationship between the microbiota, particularly enriched with the tryptophan metabolism gene EC:1.13.11.11, and intestinal cells. This symbiotic collaboration results in the biosynthesis of kynurenic acid (KYNA), which modulates the recruitment and aggregation of GPR35-positive macrophages. Subsequently, a robust T helper 17 (Th17) immune response is activated, ultimately triggering the onset of EAE. Conversely, modulating the KYNA-mediated GPR35 signaling in Cx3cr1+ macrophages leads to a remarkable amelioration of EAE. These findings shed light on the crucial role of microbial-derived tryptophan metabolites in regulating immune responses within extraintestinal tissues.

General public's understanding of rare diseases and their opinions on medical resource allocation in Japan: a cross-sectional study.

BACKGROUND: Rare diseases (RDs) may impose a considerable financial burden on patients and their families. Public acceptance is essential to ensure sustainable public systems supporting RDs, especially in countries with universal healthcare coverage, such as Japan. This study aimed to explore the public's understanding of RDs and identify crucial factors associated with the public acceptance of prioritizing financial support for RDs in Japan. METHODS: An online questionnaire was sent to 131,220 Japanese residents aged 20-69 years. The items included in the questionnaire were general interest in medical science and medical care, general knowledge regarding RDs and health care systems, opinions on the cost of medical care, opinions on the research and development of RDs and common diseases, and individual characteristics. RESULTS: The responses of 11,019 respondents were analyzed. Several respondents agreed to partially cover the medication cost of adult and pediatric RDs (59.5% and 66.8%, respectively) with public funding. The major reasons for agreeing were the huge financial burden imposed on patients and their families, limited available treatment options, effects of RDs on the life planning of patients, and difficulties caused by RDs in the patient's social life. Furthermore, the respondents ranked RDs (56.0%) higher than common diseases (44.0%) for government funding for research and development. The reasons for supporting government-funded research and development for RDs included the lack of treatment options for numerous RDs (34.9%) and difficulty of studying RDs owing to the small number of researchers (25.9%). The chief reasons for supporting government-funded research and development for common diseases were the large number of affected patients (59.7%) and the possibility of more treatment options becoming available through the promotion of research and development (22.1%). CONCLUSIONS: The general public considers burdens associated with daily living or finance more than the epidemiological characteristics of RD while making funding decisions, demonstrating that rarity was less prioritized. A gap appears to exist between the general public and RD experts regarding the understanding of the epidemiological characteristics of RD and its thresholds. This gap should be bridged to ensure that prioritization of financial support for RDs is accepted by the society.

Significance of 5-Aminosalicylic Acid Intolerance in the Clinical Management of Ulcerative Colitis.

BACKGROUND: Two major types of 5-aminosalicylic acid (5-ASA)-containing preparations, namely, mesalazine/5-ASA and sulfasalazine (SASP), are currently used as first-line therapy for ulcerative colitis. Recent reports show that optimization of 5-ASA therapy is beneficial for both patient outcomes and healthcare costs. Although 5-ASA and SASP have good efficacy and safety profiles, clinicians occasionally encounter patients who develop 5-ASA intolerance. SUMMARY: The most common symptoms of acute 5-ASA intolerance syndrome are exacerbation of diarrhea, fever, and abdominal pain. Patients who discontinue 5-ASA therapy because of intolerance have a higher risk of adverse clinical outcomes, such as hospital admission, colectomy, need for advanced therapies, and loss of response to anti-tumor necrosis factor (TNF) biologics. When patients develop symptoms of 5-ASA intolerance, the clinician should consider changing the type of 5-ASA preparation. Recent genome-wide association studies and meta-analyses have shown that 5-ASA allergy is associated with certain single-nucleotide polymorphisms. Although there are no modalities or biomarkers for diagnosing 5-ASA intolerance, the drug-induced lymphocyte stimulation test can be used to assist in the diagnosis of acute 5-ASA intolerance syndrome with high specificity and low sensitivity. This review presents a general overview of 5-ASA and SASP in the treatment of inflammatory bowel disease and discusses the latest insights into 5-ASA intolerance. KEY MESSAGES: 5-ASA is used as first-line therapy for ulcerative colitis. Optimization of 5-ASA may be beneficial for patient outcomes and healthcare systems. Acute 5-ASA intolerance syndrome is characterized by diarrhea, fever, and abdominal pain. Periodic renal function monitoring is recommended for patients receiving 5-ASA.

Incisional wound closure by sequential partial split-thickness skin grafting following failure of primary abdominal fascia closure after open abdomen management: A case report.

INTRODUCTION: Open abdomen (OA) is a widely used technique for managing abdominal organ injury, abdominal compartment syndrome, and abdominal sepsis. While various methods have contributed to successful primary closure of the abdominal fascia after OA, some patients still develop enteroatmospheric fistulas that impede abdominal fascia closure. We report a case of successful epithelialization of the incision by sequential partial split-thickness skin grafting (STSG) in a patient who had failure in primary abdominal fascia closure due to enteroatmospheric fistulas after OA for incisional dehiscence and anastomotic leakage. PRESENTATION OF CASE: A 73-year-old male patient underwent pancreaticoduodenectomy for duodenal adenocarcinoma. The abdominal incision was then necrosed and dehisced due to anastomotic leakage on postoperative day (POD) 6, and multiple intra-abdominal lavages with OA were performed. On POD 15, the patient developed enteroatmospheric fistulas; thus, primary fascia closure was considered impossible. On PODs 72 and 106, STSG was conducted on the granulation tissue at the incisional wound, and complete epithelialization was achieved on POD 111. DISCUSSION: Sequential partial STSG only needed basic surgical skills and standard devices for surgery. CONCLUSION: We reported the case with successful epithelialization of the incision by sequential partial STSG, in which primary abdominal fascia closure was failed due to enteroatmospheric fistulas after OA for incisional dehiscence and anastomotic leakage.

Effect of firing temperature on the interface between 3Y-TZP zirconia and porcelain.

PURPOSE: The purpose of this study is to clarify the porcelain firing temperature conditions that give strongest bonding strength of porcelain to zirconia to manufacture all-ceramic fixed dental prostheses (FDPs) with excellent long-term stability. METHODS: Opaque porcelain samples (8.0 × 3.0 × 1.2 mm) were placed in the center of zirconia plates (25.0 × 3.0 × 0.5 mm) and fired at temperatures of 950°C, 1,050°C, 1,100°C, and 1,150°C. Schwickerath crack initiation tests, elemental analyses, and morphological changes of the samples were compared. RESULTS: There was no difference in the bonding strength among all the groups of porcelain fired at different temperatures. Elemental analysis of Si and O2 at the interface between the zirconia and porcelain were observed in the 950°C, 1,050°C, and 1,100°C groups. No silicon was found in the 1,150°C group by elemental analysis, and the zirconia plate where the porcelain sample was placed had irregular shape changes. CONCLUSION: It is suggested that silicon is also involved in chemical bonds due to firing at high temperatures.

Effects of porcelain veneering methods on conformity of the marginal and internal fit of three-unit zirconia framework.

The purpose of this study is to investigate the effects of porcelain veneering methods on the marginal and internal fit of a three-unit zirconia framework. A zirconia master model, in which the lower-left second premolar and the second left molar were used as the abutment, was obtained using an intraoral scanner. Based on the data, three-unit zirconia frameworks for fabricating all-ceramic bridges were designed and milled (FW group). Two types of all-ceramic bridge were fabricated by veneering porcelain onto these frameworks using the press-over technique (P group) and the layering technique (L group). The replica technique was used to measure the gap size between the abutments and the bridges. Measurements were taken in the marginal opening area (MO), chamfer area (CH), axial area (AX), and occlusal area (OC). Statistical analysis was performed using the Mann-Whitney U-test. There was no significant difference in MO and CH between the P and L groups. However, in AX, the L group had a significantly larger gap size than that of the P group (p = 0.003). In addition, compared with the FW group, the P group showed a significantly larger gap size in MO (p < 0.000), CH (p = 0.008), and OC (p < 0.000). These results indicate that the gap size increased after porcelain veneering using the press-over and layering techniques. In addition, the all-ceramic bridges fabricated using the press-over and layering techniques had approximately equal gap sizes in MO.

Safety and Recipient Satisfaction of Propofol Sedation in Outpatient Endoscopy: A 24-Hour Prospective Investigation Using a Questionnaire Survey.

BACKGROUND/AIMS: The aim of this study was to evaluate the safety of sedation with propofol as an alternative to benzodiazepine drugs in outpatient endoscopy. METHODS: In this prospective study, examinees who underwent outpatient endoscopy under propofol sedation and submitted a nextday questionnaire with providing informed consent were evaluated. Periprocedural acute responses, late adverse events within 24 hours, and examinee satisfaction were evaluated. RESULTS: Among the 4,122 patients who received propofol in the 17,978 outpatient-based endoscopic examinations performed between November 2016 and March 2018, 2,305 eligible examinees (esophagogastroduodenoscopy for 1,340, endoscopic ultrasonography for 945, and total colonoscopy for 20) were enrolled, and their responses to a questionnaire were analyzed. The mean propofol dose was 69.6±24.4 mg (range, 20-200 mg). Diazepam, midazolam, and/or pentazocine in combination with propofol was administered to 146 examinees. Mild oxygen desaturation was observed in 59 examinees (2.6%); and mild bradycardia, in 2 (0.09%). Other severe reactions or late events did not occur. After eliminating 181 invalid responses, 97.7% (2,065/2,124) of the patients desired propofol sedation in future examinations. CONCLUSION: Propofol sedation was found to be safe-without severe adverse events or accidents-for outpatient endoscopy on the basis of the patients' next-day self-evaluation. Given the high satisfaction level, propofol sedation might be an ideal tool for painless endoscopic screening.

Predictive Factors for Short-Term Survival after Non-Curative Endoscopic Submucosal Dissection for Early Gastric Cancer.

BACKGROUND/AIMS: For early gastric cancer (EGC) treated using endoscopic submucosal dissection (ESD) with poor curability defined by the Japanese Guidelines (non-curative EGC, N-EGC), additional gastrectomy has been recommended. However, N-EGC patients without additional gastrectomy often die of other diseases within a relatively short interval after ESD. It has been unclear whether additional gastrectomy is beneficial or not for such patients. The aim of this study was to clarify predictors for short-term survival of N-EGC patients without additional gastrectomy after ESD. METHODS: One hundred six N-EGC patients without additional gastrectomy were included in this study. Factors related to short-term survival, defined as death within 3 years after ESD, were evaluated using uni- and multivariate analyses by comparing patients with and without short-term survival (Groups S and C, respectively). RESULTS: During the mean follow-up period of 89 months, 39 patients died (14 patients died within 3 years, being Group S). The cause of death was gastric cancer for only 1 patient in the Group C. The 3- and 5-year overall survival rates were 86.8 and 81.8%, respectively, and the 3- and 5-years disease-specific survival rates were 100 and 98.9%, respectively. Univariate analyses showed that short-term survival was statistically associated with elevated morphology, high-risk status for lymph node metastases as defined by the eCura system, severe comorbidity (Charlson Comorbidity Index [CCI] ≥3), low level of activity in daily living (being unable to go out by oneself), habitation (a nursing home), and several poor nutritional prognostic indices (neutrophil to lymphocyte ratio ≥2.5, geriatric nutritional risk index <92, C-reactive protein ≥1.0). In the multivariate analysis, a high CCI (≥3) was the independent predictor for short-term survival after ESD (odds ratio, 8.1; 95% confidence interval, 1.53-43.0; p = 0.014). CONCLUSIONS: Severe comorbidity indicated by a high CCI score (≥3) was the independent predictor for short-term survival for EGC patients without additional gastrectomy after non-curative ESD. Since the cause of death for most patients was not gastric cancer, observational follow-ups without additional gastrectomy might be a reasonable option for patients with a poor general status indicated by a CCI ≥3.

Development of a Semiautomatic Dura Mater Suturing Device for Preventing Cerebrospinal Fluid Leakage in Transsphenoidal Surgery.

Dural suturing in transsphenoidal surgery requires well-honed technical skills. We have developed a semiautomatic dural suturing device and confirmed its effectiveness by comparing it with the conventional method. This device significantly shortens the suturing time compared with the conventional method. The dural suturing time in transsphenoidal surgery could be decreased significantly by use of this novel device.

Marginal and internal fit of three-unit fixed dental prostheses fabricated from translucent multicolored zirconia: Framework versus complete contour design.

STATEMENT OF PROBLEM: Translucent multicolored zirconia materials enable more esthetic complete contour zirconia fixed dental prostheses (FDPs) than conventional zirconia, which exhibits low translucency and high opacity and is monochromatic. However, how the marginal and internal fit of translucent multicolored zirconia FDPs compare with those of traditional frameworks that require veneering is unclear. PURPOSE: The purpose of this in vitro study was to compare the marginal and internal fit of frameworks and complete contour 3-unit FDPs fabricated from translucent multicolored zirconia. MATERIAL AND METHODS: Frameworks with a thickness of 0.5 mm and complete contour FDPs with a thickness of 0.8 to 1.5 mm were manufactured by using a workflow similar to one from a zirconia master model (mandibular left second premolar-mandibular left second molar). Two polyvinyl siloxane replicas were made for each specimen to measure the marginal and internal fit. Measurement locations were mesial, lingual, buccal, and distal for each abutment. In these locations, the marginal opening (MO), chamfer area (CA), axial wall (AW), and occlusal area (OC) were measured. The data were analyzed with 2-way ANOVA and the Bonferroni post hoc test (α=.05). RESULTS: Frameworks showed significantly better mean ±standard deviation fit values than complete contour 3-unit FDPs at measurement areas MO (frameworks: 112 ±22 µm, complete contour FDPs: 144 ±37 µm) (P=.013), CA (frameworks: 89 ±12 µm, complete contour FDPs: 110 ±22 µm) (P=.006), and OC (frameworks: 182 ±36 µm, complete contour FDPs: 244 ±64 µm) (P=.008). At the measurement area AW (frameworks: 47 ±7 µm, complete contour FDPs: 50 ±9 µm of each location, no significant difference was observed between frameworks and complete contour FDPs (P=.361). CONCLUSIONS: Design differences in 3-unit FDPs fabricated from translucent multicolored zirconia influenced the marginal and internal fit. Frameworks had smaller marginal fit than complete contour FDPs for translucent multicolored zirconia.

Marginal and internal fit of three-unit zirconia fixed dental prostheses: Effects of prosthesis design, cement space, and zirconia type.

PURPOSE: The purpose of this study was to compare the marginal and internal fit of three-unit fixed dental prostheses (FDPs) fabricated using CAD/CAM with two designs, two cement space (CS), and two zirconia types. METHODS: A master model with two zirconia abutments and a missing tooth was scanned with an intraoral scanner. FDPs were fabricated with two designs (Full contour: FC, Framework: FW), two zirconia types (multi-layer: L, single-layer: W), and two CS values (30 and 45 µm for L and 30 µm for W). There were six experimental groups. The fit of the FDPs was evaluated using the replica method. The space between an abutment and the FDPs in the marginal (MO), chamfer (CH), axial (AX), and occlusal (OC) areas was measured under an optical microscope and the data was statistically analyzed using three-way ANOVA and Bonferroni test (p < 0.05). RESULTS: FW-l-45 µm showed a significantly smaller space than those for the FC in MO (p = 0.011), CH (p = 0.001) and AXE (p = 0.003). FW-l-30 µm showed a significantly smaller space than that for the 45 µm in AXE (p = 0.000) and OC (p = 0.016). FW-W-30 µm showed a significantly smaller space than that for the L in MO (p = 0.000), CH (p = 0.000), AXE (p = 0.000), and OC (p = 0.002). CONCLUSIONS: The design and CS of the FDPs affected the fit. FDPs with single-layer zirconia showed better fit than that obtained with multi-layer zirconia.

Microsatellite markers for multiple Pocillopora genetic lineages offer new insights about coral populations.

Population genetics of the coral genus Pocillopora have been more intensively studied than those of any other reef-building taxon. However, recent investigations have revealed that the current morphological classification is inadequate to represent genetic lineages. In this study, we isolated and characterized novel microsatellite loci from morphological Pocillopora meandrina (Type 1) and Pocillopora acuta (Type 5). Furthermore, we characterized previously reported microsatellite loci. A total of 27 loci (13 novel loci) proved useful for population genetic analyses at two sites in the Ryukyu Archipelago, in the northwestern Pacific. Clonal diversity differed in each genetic lineage. Genetic structure suggested by microsatellites corresponded to clusters in a phylogenetic tree constructed from a mitochondrial open reading frame (mtORF). In addition, we found an unknown mitochondrial haplotype of this mtORF. These microsatellite loci will be useful for studies of connectivity and genetic diversity of Pocillopora populations, and will also support coral reef conservation.

In Situ Attenuated Total Reflection Infrared Spectroscopy on Electrochemical Ammonia Oxidation over Pt Electrode in Alkaline Aqueous Solutions.

The electrochemical oxidation of ammonia over Pt electrode in alkaline aqueous solutions was studied by in situ attenuated total reflection infrared (ATR-IR) spectroscopy. In 0.1 M NH3-1 M KOH, the band ascribable to the HNH bending mode of adsorbed NH3 was confirmed at 1662-1674 cm(-1) in the potential range of 0.1-1.1 V. The intensity of this band decreased continuously with a rise in potential, indicating the oxidative consumption of adsorbed ammonia. In response to this behavior, the band at 1269 cm(-1) appeared alternatively above 0.2 V, and its intensity reached the local maximal value at ca. 0.4 V. Note that this potential of ca. 0.4 V agreed well with the onset potential of ammonia oxidation, ca. 0.45 V, in the linear sweep voltammogram. This 1269 cm(-1) band was assigned to the NH2 wagging mode of N2H4, which was one of the active intermediates, N2H(x+y,ad) (x = 1 or 2, y = 1 or 2), according to the mechanism proposed by Gerischer and Mauere. To the best of our knowledge, this is the first report for the detection of N2H4 as a reaction intermediate over Pt electrode. Furthermore, the formation of bridged NO was also observed above the onset potential of ammonia oxidation, ca. 0.5 V. Such adsorbed NO species probably inhibit the electrochemical reaction due to the occupation of reaction sites at higher potential.

Spatial pattern of cell geometry and cell-division orientation in zebrafish lens epithelium.

Cell proliferation is a key regulator of tissue morphogenesis. We examined cell proliferation and cell division in zebrafish lens epithelium by visualizing cell-cycle phases and nuclear positions, using fluorescent-labeled geminin and histone proteins. Proliferation was low in the anterior region of lens epithelium and higher in the marginal zone anterior to the equator, suggesting that the proliferation zone, called the germinative zone, is formed in zebrafish lens. Interestingly, cell-division orientation was biased longitudinally in the anterior region, shifted from longitudinal to circumferential along the anterior-posterior axis of lens sphere, and was biased circumferentially in the peripheral region. These data suggest that cell-division orientation is spatially regulated in zebrafish lens epithelium. The Hertwig rule indicates that cells tend to divide along their long axes. Orientation of long axes and cell division were biased similarly in zebrafish lens epithelium, suggesting that cell geometry correlates with cell-division orientation. A cell adhesion molecule, E-cadherin, is expressed in lens epithelium. In a zebrafish e-cadherin mutant, the long axes and cell-division orientation were shifted more longitudinally. These data suggest that E-cadherin is required for the spatial pattern of cell geometry and cell-division orientation in zebrafish lens epithelium.

Prolongation of life in rats with malignant glioma by intranasal siRNA/drug codelivery to the brain with cell-penetrating peptide-modified micelles.

New therapeutic strategies are required to develop candidate drugs and ensure efficient delivery of these drugs to the brain and the central nervous system (CNS). Small interfering RNA (siRNA)-based therapies have been investigated as potential novel approaches for the treatment of brain disorders. Previously, we showed that Tat, a cell-penetrating peptide derived from HIV-Tat, and the modified block copolymers (MPEG-PCL-Tat) can form stable complexes with siRNA or can be loaded with an anticancer drug and efficiently deliver the drugs to the brain tissue via intranasal delivery. In this study, to develop a novel, efficient, and safe therapeutic strategy for managing brain disorders, we used MPEG-PCL-Tat micelles with a nose-to-brain delivery system to investigate its therapeutic effects on a rat model of malignant glioma using siRNA with a Raf-1 (siRaf-1)/camptothecin (CPT) codelivery system. MPEG-PCL-Tat and CPT-loaded MPEG-PCL-Tat can form a stable complex with siRNA with a particle size from 60 to 200 nm and a positive charge at N/P ratios up to 5. Additionally, MPEG-PCL-Tat/siRaf-1 and CPT-loaded MPEG-PCL-Tat/siRaf-1 have fostered cell death in rat glioma cells after the high cellular uptake of siRaf-1/drug by the MPEG-PCL-Tat carrier. Furthermore, compared to the unloaded MPEG-PCL-Tat/siRaf-1 complex, a CPT-loaded MPEG-PCL-Tat/siRaf-1 complex achieved the high therapeutic effect because of the additive effects of CPT and siRaf-1. These results indicate that drug/siRNA codelivery using MPEG-PCL-Tat nanomicelles with nose-to-brain delivery is an excellent therapeutic approach for brain and CNS diseases.

Testing the low-density hypothesis for reversed sex change in polygynous fish: experiments in Labroides dimidiatus.

Hermaphroditism is ubiquitous among plants and widespread in the animal kingdom. It is an unsolved problem why reversed sex change has evolved in polygynous and protogynous reef fish. We have previously suggested that facultative monogamy occurs in low-density populations of polygynous species and that males that become single as a result of accidental mate loss may change sex when they meet larger males. In this study, to test this 'low-density hypothesis', we conducted field experiments with the coral reef fish Labroides dimidiatus in which a portion of females were removed to create a low-density situation. The 'widowed' males moved to search for a new mate when no male, female or juvenile fish migrated into their territories and paired with nearby single fish, whether male or female. Alternatively, males expanded their territories to take over the nearest pair whose male was much smaller. These results support our low-density hypothesis.

The BH3-only SNARE BNip1 mediates photoreceptor apoptosis in response to vesicular fusion defects.

Intracellular vesicular transport is important for photoreceptor function and maintenance. However, the mechanism underlying photoreceptor degeneration in response to vesicular transport defects is unknown. Here, we report that photoreceptors undergo apoptosis in a zebrafish ß-soluble N-ethylmaleimide-sensitive factor attachment protein (ß-SNAP) mutant. ß-SNAP cooperates with N-ethylmaleimide-sensitive factor to recycle the SNAP receptor (SNARE), a key component of the membrane fusion machinery, by disassembling the cis-SNARE complex generated in the vesicular fusion process. We found that photoreceptor apoptosis in the ß-SNAP mutant was dependent on the BH3-only protein BNip1. BNip1 functions as a component of the syntaxin-18 SNARE complex and regulates retrograde transport from the Golgi to the endoplasmic reticulum. Failure to disassemble the syntaxin-18 cis-SNARE complex caused BNip1-dependent apoptosis. These data suggest that the syntaxin-18 cis-SNARE complex functions as an alarm factor that monitors vesicular fusion competence and that BNip1 transforms vesicular fusion defects into photoreceptor apoptosis.

Reversed sex change by widowed males in polygynous and protogynous fishes: female removal experiments in the field.

Sex change, either protogyny (female to male) or protandry (male to female), is well known among fishes, but evidence of bidirectional sex change or reversed sex change in natural populations is still very limited. This is the first report on female removal experiments for polygnous and protogynous fish species to induce reversed sex change in the widowed males in the field. We removed all of the females and juveniles from the territories of dominant males in the cleaner wrasse Labroides dimidiatus (Labridae) and the rusty angelfish Centropyge ferrugata (Pomacanthidae) on the coral reefs of Okinawa. In both species, if new females or juveniles did not immigrate into the territories of the widowed males, some of them emigrated to form male-male pairs. When a male-male pair formed, the smaller, subordinate partner began to perform female sexual behaviours (n = 4 in L. dimidiatus; n = 2 in C. ferrugata) and, finally, released eggs (n = 1, respectively). Thus, the reversed sex change occurred in the widowed males according to the change of their social status. These results suggest that such female removal experiments will contribute to the discovery of reversed sex change in the field also in other polygnous and protogynous species.