Compatibility of the semijailing technique with extremely soft i-ED coils for ruptured blood blister-like and dissecting aneurysms: patient series.

BACKGROUND: Optimal treatment options for ruptured blood blister-like aneurysms (BBAs) and dissecting aneurysms (DAs) have not yet been established. Endovascular treatment may achieve vessel reconstruction with the preservation of antegrade blood flow; however, securing curative hemostasis at the fragile rupture point remains a major concern. OBSERVATIONS: Two ruptured BBAs and two ruptured DAs treated by stent-assisted coiling with the semijailing technique in the last 2 years are described herein. The devices used were braided stents and i-ED coils, which are new low-memory shape and extremely soft coils. Neither rebleeding nor ischemic complications were observed. All patients had a favorable outcome and showed no recurrence after treatment. LESSONS: All aneurysms were treated without ischemic complications or rebleeding. The good compatibility of braided stents and the new concept coils in stent-assisted coiling by the semijailing technique provides insight into these intractable hemorrhagic vascular pathologies.

High signal intensity of the intraaneurysmal sac on T1 CUBE imaging as a predictor of aneurysm stability after coil embolization.

OBJECTIVE: Histopathological studies of aneurysms after coil embolization showed that thrombus formation during the first month after endovascular treatment (EVT) played an important role in the healing process. The authors hypothesized that dedicated T1-weighted imaging may be used to predict stable aneurysms by visualizing the thrombus status within coil-treated aneurysms. Therefore, this study investigated the relationship between the signal intensity (SI) of the intraaneurysmal sac after coil embolization and aneurysm stability. METHODS: The study population included 82 patients with 86 aneurysms who underwent T1-weighted 3D black-blood fast spin-echo (T1 CUBE) imaging within 1 month after coil embolization between 2019 and 2022. The relative SI of a coil-treated aneurysm (RSIcoiled) was calculated as follows: the mean SI of the intraaneurysmal sac/the mean SI of the genu of the corpus callosum. Aneurysms with enlarged remnants on MR angiography (MRA) within 6 months after EVT were defined as recurrence, while a decrease of intraaneurysmal flow on MRA was defined as improved embolization status. Stable aneurysms were defined as improvement or no change in embolization status 6 months after coil embolization. The volume embolization ratio (VER) was calculated as the ratio of the packed coil volume to the aneurysm volume. Differences between stable and recurrent aneurysms were examined. All aneurysms were divided into high and low RSIcoiled groups based on the cutoff value of RSIcoiled, and differences between the two groups were also evaluated. RESULTS: Recurrence was confirmed for 26 of 86 aneurysms. A univariable analysis showed that small aneurysms, high VER, and high RSIcoiled were associated with aneurysm stability. In the receiver operating characteristic curve analysis, the optimal cutoff value for RSIcoiled to differentiate stable from recurrent aneurysms was 0.54. The cutoff value for RSIcoiled was selected as 0.50 (sensitivity 0.77, specificity 0.70) because it was half the value of the SI of the corpus callosum and close to the optimal cutoff value. In a multivariable analysis, RSIcoiled > 0.50 (OR 8.1, 95% CI 2.5-27) remained a significant factor for aneurysm stability. The high RSIcoiled group showed a higher rate of an improved embolization status (26% vs 6.1%, p = 0.022) and stable aneurysms (85% vs 15%, p = 0.0002). CONCLUSIONS: RSIcoiled was associated with postcoiling aneurysm stability. High RSIcoiled might imply intraaneurysmal thrombus formation associated with the healing process of coil-treated aneurysms.

Distribution of osteoprotegerin in unruptured intracranial aneurysms in humans: association with aneurysm wall protective remodeling.

OBJECTIVE: Aneurysm wall inflammation is associated with lesion instability in unruptured intracranial aneurysms (UIAs). However, most UIAs remain unruptured during lifelong follow-ups because of simultaneous protective remodeling against the inflammatory response. The protective effects of osteoprotegerin (OPG) in intracranial and abdominal aortic aneurysms have been suggested using rodent models; however, the role of this protein in UIAs in humans remains unclear. Herein, the authors examined the relationship between OPG expression and aneurysm wall integrity in intraoperatively resected UIAs by using immunohistochemical and immunofluorescence staining. METHODS: Sixteen UIA wall tissue specimens resected between 2017 and 2022 were analyzed. Aneurysm growth was defined as an enlargement > 1 mm or an obvious morphological change over the course of more than 6 months. Three high-power fields were randomly selected from areas expressing high and low levels of OPG within the same aneurysm. To clarify the role of OPG in the human aneurysm wall, the authors compared averaged values for the following pathological features between the 2 OPG expression groups: aneurysm wall thickness, collagen, macrophages, smooth muscle cells, and transforming growth factor beta 1 (TGF-ß1). Immunohistochemical staining within the entire tissue area was also analyzed to determine the relationships between OPG expression and different aneurysm growth patterns. Pathological findings were compared between high and low OPG expression levels using the Wilcoxon signed-rank test. RESULTS: The heterogeneous expression of OPG was detected in the walls of UIAs. Lesions expressing high OPG levels had thicker aneurysm walls (327 vs 180 µm, p = 0.002) and higher expression levels of TGF-ß1 (8.5% vs 5.4%, p = 0.002) than those expressing low OPG levels. The expression of TGF-ß1 was colocalized with that of OPG mainly in the tunica media. Furthermore, lesions expressing high OPG levels had larger α-SMA+ areas (25% vs 13%, p = 0.002). Aneurysm growth was observed in 6 of 9 UIAs with available data: whole sac expansion in 4 and secondary aneurysm formation in 2. Among the 6 UIAs with aneurysm growth, OPG expression was relatively higher in the UIAs with an internal elastic lamina than in those without (17% vs 6.9%). CONCLUSIONS: Aneurysm wall integrity was associated with OPG expression in the aneurysm wall. Collectively, the study results indicated that OPG is associated with protective remodeling, which may contribute to the retention of aneurysm wall structures.

Headache characteristics to screen for cervicocerebral artery dissection in patients with acute onset unusual headache.

OBJECTIVES: The aim of this preplanned primary analysis was to investigate the clinical manifestations of headache to screen for CAD patients with acute onset headache only. BACKGROUND: Spontaneous cervicocerebral artery dissection (CAD) with acute onset headache is not rare in clinical practice; however, it is underdiagnosed. On the other hand, subsequent infarction or subarachnoid hemorrhage mainly occurs within 1 week of headache onset. METHODS: Between April 2017 and January 2022, we conducted a single-center, cross-sectional retrospective study on 197 consecutive referred patients from neurosurgical outpatient clinics with acute onset unusual headache (stronger or longer headache than usual). All patients underwent magnetic resonance imaging to screen for secondary headache and were diagnosed based on the diagnostic protocol. We examined patient background data and the following headache characteristics: distribution, condition at the onset of headache, accompanying vomiting or nausea, worsening headache, and analgesic effects against headache. These factors were analyzed to identify independent diagnostic predictors of CAD. In this study, the rate of missing data was 41% for improvement of headache by analgesia and multiple imputation by chained equations was performed. RESULTS: A total of 93 patients (46 men and 47 women; mean age: 48 years, range: 25-73 years) were diagnosed with CAD. Univariate logistic regression analysis showed CAD was associated with current smoking, systolic blood pressure >140 mmHg, unilateral headache, worsening headache, and no headache improvement by analgesia. Unilateral, worsening headache and no headache improvement by analgesia remained independent diagnostic predictors in multivariable logistic regression after multiple imputation. No headache improvement by analgesia had the highest sensitivity (86%), while worsening headache had the highest specificity (84%). CONCLUSIONS: CAD needs to be considered in patients with unilateral, worsening headache and no headache improvement by analgesia.

Bidirectional effects of voluntary exercise on the expression of Bdnf isoforms in the hippocampus of Hatano rat strains displaying different activity levels.

Brain-derived neurotrophic factor has functional mRNA isoforms, whose expression is assumed to mediate the beneficial effects of exercise in neuropsychiatric disorders. This study aims to reveal the mechanism of intensity-dependent effects of voluntary exercise, focusing on the expression of Bdnf mRNA isoforms in Hatano rats. Animals with different voluntary activity were housed in cages with a locked or unlocked wheel for 5 weeks. The expression levels of Bdnf isoforms and the corresponding coding sequences (CDS) were measured in the hippocampus using real-time polymerase chain reaction (PCR). We found that exercise increased the expression of Bdnf isoform containing exon 1 in the high-intensity-running strain and decreased the expressions of Bdnf exon 1, 3, 6, 7, 8, and 9a in mild-intensity-running animal. The expression of Bdnf CDS was increased by exercise in both strains. These results suggest that expressions of Bdnf isoforms depend on the intensities of voluntary exercise, but the involvement of subjects' genetic background could not be excluded. Our finding also implies that the bidirectional effects of exercise may not be mediated via the final product of Bdnf.

Association of circumferential aneurysm wall enhancement with recurrence after coiling of unruptured intracranial aneurysms: a preliminary vessel wall imaging study.

OBJECTIVE: Recent histopathological studies of unruptured intracranial aneurysms (UIAs) have confirmed that aneurysm wall enhancement (AWE) on MR vessel wall imaging (VWI) is related to wall degeneration with in vivo inflammatory cell infiltration. Therefore, pretreatment aneurysm wall status on VWI may be associated with recurrence after endovascular treatment. METHODS: VWI with gadolinium was performed on 67 consecutive saccular UIAs before endovascular treatment between April 2017 and June 2021. The mean (range) follow-up period after treatment was 24.4 (6-54) months. AWE patterns were classified as circumferential AWE (CAWE), focal AWE (FAWE), and negative AWE (NAWE). The authors retrospectively investigated the relationship between aneurysm recurrence and AWE patterns, as well as conventional risk factors. RESULTS: Sixty-seven patients with 67 saccular UIAs were eligible for the present study. AWE patterns were as follows: 10 CAWE (14.9%), 20 FAWE (29.9%), and 37 NAWE (55.2%). Follow-up MRA detected aneurysm recurrence in 18 of 69 cases (26.1%). Univariate analysis identified maximum diameter (mean ± SD 5.8 ± 2.2 mm in patients with stable aneurysms vs 7.7 ± 3.8 mm in those with unstable aneurysms, p = 0.02), aspect ratio (1.4 ± 0.5 vs 1.1 ± 0.4, p < 0.01), aneurysm location in posterior circulation (4.1% vs 27.8%, p < 0.01), volume embolization ratio (29.6% ± 7.8% vs 25.2% ± 6.1%, p = 0.02), and AWE pattern (p = 0.04) as significant predictive factors of recurrence. Among the 3 AWE patterns, CAWE was significantly more frequent in the unstable group, but no significant differences in stability of the treated aneurysms were observed with the FAWE and NAWE patterns. In multivariate logistic regression analysis, CAWE pattern (OR 14.2, 95% CI 1.8-110.8, p = 0.01) and volume embolization ratio ≥ 25% (OR 8.6, 95% CI 2.1-34.3, p < 0.01) remained as significant factors associated with aneurysm stability after coiling. CONCLUSIONS: VWI before coiling provides novel insights into the stability of treated aneurysms. Aneurysms with the CAWE pattern on VWI before coiling may be less stable after treatment.

The impact of high-resolution cone-beam CT findings on decision-making for the treatment of unruptured middle cerebral artery aneurysms.

Even with the advent of endovascular treatment for intracranial aneurysms, microsurgical clipping continues to play a significant role in the treatment of middle cerebral artery (MCA) aneurysms. Securing perforators around unruptured intracranial aneurysms (UIAs) is essential for minimizing procedural risks in each treatment option. Therefore, we herein investigated whether the findings of high-resolution cone-beam computed tomography (HR-CBCT) have an impact on decision-making for the treatment of MCA UIAs. Patients with MCA UIAs between October 2017 and September 2021 were consecutively recruited for this study. All patients underwent HR-CBCT and 3D-DSA before treatment. The imaging quality of both modalities to visualize the microvasculature around aneurysms was evaluated. Specific findings on the microvasculature surrounding aneurysms on HR-CBCT were investigated to facilitate microsurgical clipping. Fifty-two MCA UIAs were treated, including 43 by microsurgical clipping and 9 by endovascular approaches. The overall imaging quality of HR-CBCT was superior to that of 3D-DSA. Regarding microsurgical insights, sensitivity and specificity for the visualization of small vessels around aneurysms were 79 and 100%, respectively, using HR-CBCT, and 57 and 93%, respectively, using 3D-DSA. The presence of a low-density band between adhesive vessels and aneurysm sacs was indicative of successful and safe microsurgical dissection between these structures. HR-CBCT enabled visualization of the intracranial microvasculature around MCA UIAs at the submillimeter level in vivo. In cases in which the tight adhesion of the microvasculature to the aneurysm sac is indicated by HR-CBCT, an endovascular approach may be considered in order to avoid the risks associated with securing perforators.

Age-related accumulation of persistent organic chemicals in captive king penguins (Aptenodytes patagonicus).

Persistent organic chemicals are non-biodegradable in nature and have a tendency to bioaccumulate in the top organisms of the food chain. We measured persistent organic chemicals, including polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and benzotriazole-based ultraviolet stabilizers (UV-BTs), in the serum of captive king penguins (Aptenodytes patagonicus) using gas chromatography with an electron capture detector and mass spectrometry to examine their age-related accumulation. PCBs, DDE, UV-PS, and UV-9 were detected in the blood of captive king penguins, and the concentrations of total PCBs, DDE, and UV-9 were positively correlated with age. These results suggest that there is a similar age-related accumulation of persistent organic chemicals in marine birds in the wild, and that older individuals are at a higher risk of contamination.

Diagnostic accuracy of MR vessel wall imaging at 2 weeks to predict morphological healing of vertebral artery dissection.

OBJECTIVES: The spontaneous healing of non-hemorrhagic intracranial vertebral artery dissection (VAD) may be associated with the stabilization of intramural hematoma (IMH). We previously suggested that the signal intensity of IMH increases until approximately 2 weeks in VAD with spontaneous healing. We herein investigated the diagnostic accuracy of the signal intensity of IMH at 2 weeks to predict the spontaneous healing of VAD. METHODS: From April 2017 to April 2021, we prospectively investigated patients with non-hemorrhagic VAD who underwent vessel wall imaging (VWI). Morphological healing of VAD was evaluated by MR angiography three months after its onset. The relative signal intensity (RSI) of IMH against the posterior cervical muscle on VWI was calculated. Univariate and multivariate analyses were performed on factors associated with the spontaneous healing of VAD among patient baseline data, vascular morphology at the diagnosis, and RSI parameters. RESULTS: Forty-eight patients (23 men and 25 women; mean age: 51 years, range: 34-73 years) with 50 non-hemorrhagic VAD were included in the present study. Spontaneous healing was observed in 28 VAD (56%). RSI two weeks after the onset of VAD (RSI2w) and morphological feature such as the string sign were associated with spontaneous healing, respectively. The multivariate logistic regression analysis identified RSI2w as an independent predictive factor of spontaneous healing (OR: 7.3; 95% CI, 1.9-28, p = 0.004). The cut-off value for RSI2w to predict spontaneous healing was 1.22 (AUC = 0.90, sensitivity: 91%, specificity: 82%). CONCLUSION: RSI2w predicted the spontaneous healing of non-hemorrhagic VAD 3 months after its onset.

Effects of sugar cane extract on steroidogenesis in testicular interstitial cells of male Japanese quail (Coturnix japonica).

Sugar cane extract (SCE) is the end product of glucose, fructose, and sucrose elimination in molasses. SCE has various biological effects, such as anti-inflammation and antioxidation, and it is commonly found in animal feed. The present research is aimed at investigating the reproductive endocrine influence of SCE in male Japanese quails (Coturnix japonica) by feeding SCE containing food. In addition, in vitro Leydig cell culture was conducted to clarify the mechanism of SCE's influence. Our results showed that SCE feed extended the latency to the first neck grab, decreased male quail testis and epididymis weights, cloaca gland size, and reduced serum testosterone concentrations. Steroidogenic enzymes 3ßHSD, 17ßHSD, P450c17, and P450scc gene expression in the testis were decreased in the SCE groups. Western blot analysis showed decreased 3ßHSD in the testis after feeding SCE. Isolated testicular interstitial cells cultured with SCE and ovine-LH suppressed testosterone secretion and 3ßHSD gene expression. In conclusion, SCE as a feed additive has an impact on the sexual behavior and reproductive function of male Japanese quail, with the suppression of steroidogenesis in the Leydig cell. Our results may provide beneficial information to the livestock management and the poultry industry.

Toxicological effects of Tris (1,3-dichloro-2-propyl) phosphate exposure in adult male rats differ depending on the history of exposure in the neonatal period.

There is increasing concern about multiple high concentration exposure to toxins in disaster and emergency situations. However, conventional toxicology testing methods may not adequately address these situations. Thus, we assessed whether the toxic effects of exposure in the adulthood differ depending on the presence or absence of neonatal exposure to Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) in male rats to investigate the effects of exposure history of chemicals. In the neonatal stage [postnatal days (PNDs) 1-7], animals were treated with either sesame oil (5 ml/kg/day) as a control or TDCIPP (250 mg/kg/day) dissolved in sesame oil. In adulthood (PND 101-107), animals were treated with either sesame oil (5 ml/kg/day) or TDCIPP (650 mg/kg/day). One day after the final administration, dissection was performed, and body and organ weight, hematology, blood biochemistry, and histopathology were examined. The results demonstrated that the toxic effects of TDCIPP exposure in adulthood on adrenal gland size, serum iron content, and unsaturated iron binding capacity were enhanced by TDCIPP exposure in the neonatal stage. From these findings, it was indicated that the toxic effects of TDCIPP exposure in the adult stage are affected by pediatric exposure. These results suggest that the toxic effects of high-dose and long-term unsteady exposure to chemicals in large-scale disasters may change based on the exposure history of chemicals.

Possible effects of voluntary exercise intensity on anxiety-like behavior and its underlying molecular mechanisms in the hippocampus: Results from a study in Hatano rats.

The prevalence of neuropsychiatric diseases, including anxiety disorders, has increased in recent years. A better understanding of the mechanisms mediating symptoms in these disorders is essential for developing treatments. Although voluntary exercise can alleviate symptoms, its anxiolytic effect varies with the intensity of the activity. Therefore, to investigate the usefulness of voluntary exercise in alleviating the symptoms of neuropsychiatric disorders, assessing its effect based on intensity is required. Hatano rats, consisting of high- and low-avoidance animals (HAA and LAA, respectively), differ in their propensity to voluntary exercise. These animals are useful for examining the effects of voluntary running activity differing in intensity on anxiety-like behavior. We housed Hatano rats in cages containing locked or unlocked running wheels starting at 4 weeks of age, conducted elevated plus maze test at 8 weeks of age, followed by plasma corticosterone measurement and DNA microarray analysis on hippocampal tissue at 9 weeks of age. Our results show that only LAA (mild-intensity running animals), but not HAA (high-intensity running animals), had reduced anxiety-like behavior without plasma corticosterone change. In addition, LAA had increased immunity-related gene expression, but decreased proteolysis-related gene expression. Our findings suggest that mild-intensity voluntary running mediates the anxiolytic effect of exercise and is regulated through increasing the expression of immunity-related genes or decreasing the expression of proteolysis-related genes in the hippocampus.

[Craniopharyngioma Mimicking Chordoid Glioma].

Entirely intrinsic third ventricular craniopharyngiomas showed characteristics of a round/oval shaped tumor, with rare calcification and cyst formation, and pathologically squamous-papillary type with a positive BRAFV600E mutation. We report an extremely rare case of entirely intrinsic third ventricular craniopharyngioma, pathologically adamantiomatous but with BRAFV600E mutation genetically, developed in a 35-year-old female. It was oval-shaped, with no calcification or cyst, and showed homogeneous enhancement. As shown in this case, it was difficult to differentiate this pathology from chordoid glioma of third ventricle, and the difficulty of this differential diagnosis has not been well documented in previous studies. Our case further implied the importance of molecular diagnosis for subclassification of craniopharyngioma. The BRAFV600E-mutated craniopharyngioma could be the target for the development of treatment with preoperative BRAF-inhibitors. Therefore, differentiation between entirely intrinsic third ventricular craniopharyngiomas and chordoid glioma could be new issue. In this report, we discuss about the preoperative differential diagnosis from chordoid glioma and the literature review. (Received 12 August, 2021; Accepted 21 September, 2021; Published 1 February, 2022).

The positive relationship between androgens and hematocrit levels in the Japanese quail (Coturnix japonica).

Studies have confirmed the involvement of androgens in bird erythropoiesis, suggesting its potential function as a mediator thereof. However, little is known on whether anti-androgenic treatment reduces erythropoiesis and whether changes in endogenous androgen levels are reflected in red blood cell (RBC) indices in birds. Clarifying such issues would highlight the importance of androgens in mediating avian erythropoiesis and bring attention to the effects of endocrine-disrupting chemicals with anti-androgenic activity on their ecology. The present study focused on hematocrit levels among the RBC indices, as well as the relationship between androgens and hematocrit levels in the Japanese quail (Coturnix japonica). In experiment 1, daily injections (i.m.) of testosterone propionate administered to immature quails for a week dose-dependently increased their hematocrit levels. In experiment 2, daily injections (i.m.) of flutamide, a general antagonist of the androgen receptor (AR), administered to adult male quails for a week dose-dependently decreased their hematocrit levels. In experiment 3, weekly blood collection from male quails through the immature to mature stages revealed that changes in endogenous testosterone concentrations were correlated with changes in hematocrit levels along with sexual maturation. The aforementioned results suggested that androgen stimulates erythropoiesis via the ARs and further highlighted the biological importance of androgens on erythropoiesis in quails. Moreover, given that hematocrit is considered a key determinant of aerobic performance related to migration in birds, these findings highlight the need for investigating the effects of anti-androgenic chemicals on the hematology of migratory species for their conservation.

Effects of tris(1,3-dichloro-2-propyl) phosphate on epididymal sperm parameters in adult male rats.

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is widely used as a flame retardant and is known to exhibit anti-androgenic effects in vitro and in vivo. To assess the reproductive toxicity potency of TDCIPP, we investigated the effects of 7 days of TDCIPP oral administration on epididymal sperm motion and concentration in adult male Wistar-Imamichi rats. Thirty-five days after the final administration, sperm parameters were evaluated by computer-assisted sperm analysis. Results showed that sperm swimming progression and vigor and sperm concentration in TDCIPP-treated rats were unexpectedly higher than those in control rats. TDCIPP did not significantly affect the percentage of motile sperms or sperm swimming pattern. These results contribute to the understanding of the biological effects of TDCIPP.

Pharmacokinetics of CuGTSM, a Novel Drug Candidate, in a Mouse Model of Menkes Disease.

PURPOSE: Menkes disease is a rare hereditary disease in which systemic deficiency of copper due to mutation of the ATP7A gene causes severe neurodegenerative disorders. The present parenteral drugs have limited efficacy, so there is a need for an efficacious drug that can be administered orally. This study focused on glyoxal-bis (N(4)-methylthiosemicarbazonato)-copper(II (CuGTSM), which has shown efficacy in macular mice, a murine model of Menkes disease, and examined its pharmacokinetics. In addition, nanosized CuGTSM (nCuGTSM) was prepared, and the effects of nanosizing on CuGTSM pharmacokinetics were investigated. METHODS: CuGTSM or nCuGTSM (10 mg/kg) was administered orally to male macular mice or C3H/HeNCrl mice (control), and plasma was obtained by serial blood sampling. Plasma concentrations of CuGTSM and GTSM were measured by LC-MS/MS and pharmacokinetic parameters were calculated. RESULTS: When CuGTSM was administered orally, CuGTSM and GTSM were both detected in the plasma of both mouse strains. When nCuGTSM was administered, the Cmax was markedly higher, and the mean residence time was longer than when CuGTSM was administered for both CuGTSM and GTSM in both mouse strains. With macular mice, the AUC ratio (GTSM/CuGTSM) was markedly higher and the plasma CuGTSM concentration was lower than with C3H/HeNCrl mice when either CuGTSM or nCuGTSM was administered. CONCLUSION: Absorption of orally administered CuGTSM was confirmed in macular mice, and the nano-formulation improved the absorption and retention of CuGTSM in the body. However, the plasma concentration of CuGTSM was lower in macular mice than in control mice, suggesting easier dissociation of CuGTSM.

Novel toxicity of tris(1,3-dichloro-2-propyl) phosphate in adult male rats.

The widespread use of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) as a flame retardant has led to its release to the environment. Thus, the toxicological effects of TDCIPP on humans and animals are of importance. For better understanding of its potential toxicities, TDCIPP (250, 500, or 650 mg/kg/day) or vehicle control was administrated orally to adult male Wistar-Imamichi rats for 7 days. After the final administration of compounds, organ weights, histopathology, blood biochemistry, and hematology were examined. Hepatic toxicity was observed at doses ≥ 500 mg/kg/day of TDCIPP, and renal toxicity was observed at 650 mg/kg/day. The anti-androgenic activity of TDCIPP was previously confirmed in vitro and in vivo, but weights of epididymis, an androgen-dependent organ, were not affected by TDCIPP treatment in adults. Serum alkaline phosphatase activity was significantly decreased in all TDCIPP-treated rats independent of dose. Hemoglobin concentration, hematocrit, red blood cell count, and reticulocyte count were decreased in all TDCIPP-treated rats, but mean corpuscular volume, total iron-binding capacity, and serum iron were normal, suggesting that renal anemia was caused by TDCIPP. Together with previous reports on effects of anti-androgenic substances on red blood cell indices, anemia caused by TDCIPP could be due to its anti-androgenic activity. These considerations will contribute to further assessment of the toxicity of the compound.

Investigating the effects of nest shading on the green turtle (Chelonia mydas) hatchling phenotype in the Ogasawara islands using a field-based split clutch experiment.

The Ogasawara Islands are an important rookery for the green turtle (Chelonia mydas) in the North Pacific. Green turtles possess temperature-dependent sex determination, and warmer incubation temperatures produce more females than males. Therefore, conservation practices such as nest shading may be required for this population to mitigate the effect of global warming on their sex ratio. To consider the application of such conservation practices in the Ogasawara population, it is fundamental to understand how artificially modified nest environments will affect green turtle hatchling phenotypes that influence their fitness. Here, we investigated the effects of nest shading on green turtle hatchling phenotypes in the Ogasawara population by using a split clutch experiment equally separating the clutch, relocating each half-clutch into an outdoor hatchery area either with or without shading, and observing the subsequent hatchling phenotype. Our results showed that the shading treatment produced hatchlings with a better self-righting response and a larger carapace size. Additionally, the shading treatment mostly reduced the production of hatchlings with a nonmodal scute pattern and produced hatchlings with a smaller unabsorbed yolk sac, which may be associated with their residual yolk mass. These results suggest that conservation practices such as shading could alter not only the sex ratio but also the hatchling phenotype that influences their fitness. Hence, our results suggest that applications of such conservation strategies must be carefully considered.

The effects of 28-day early-life exposure to triphenyl phosphate (TPhP) on odor preference and sexual behavior in female rats.

Many chemical substances are detectable in house dust, and they are consequently taken into our bodies via the mouth and nose. Triphenyl phosphate (TPhP), a flame retardant that has an estrogen-like effect in vitro, is present in house dust at high concentrations. Estrogen exposure during development has significant influences on reproductive behavior in rodents, and its effects persist until maturity. In the present study, we investigated the effect of early life exposure to TPhP on the reproductive behavior of female rats. Oral treatment with TPhP (25 or 250 mg/kg), ethinyl estradiol (EE; 15 µg/kg) as a positive control, or sesame oil as a negative control, were given to female rats (from birth to 28 days of age). The 8-week-old rats were bilaterally ovariectomized. At 12-15 weeks of age, the rats were subjected to odor preference and sexual behavior tests. In the odor preference test, the oil group showed significantly higher preference for male odor than female odor, but the low-dose TPhP treatment group lost the preference for male odor, indicating a possible outcome of early life TPhP exposure on sexual recognition. In the sexual behavior test, both the EE and TPhP treatment groups displayed significantly less proceptive behavior. These results suggest that early life exposure to TPhP disturbs the normal sexual behavior of female rats.

Incubation and water temperatures influence the performances of loggerhead sea turtle hatchlings during the dispersal phase.

Artificial manipulation of incubation temperature has been proposed as a potential strategy for mitigating the effects of climate change on sea turtles for which sex determination is temperature-dependent, but thermal manipulation may also affect hatchling survival. Here, we demonstrated that incubation and water temperatures influenced several performance traits that contribute to the survival of loggerhead sea turtles (Caretta caretta) during the post-hatchling dispersal phase. Hatchlings from warm incubation temperatures (31 °C) had significantly shorter incubation periods, higher initial swimming performance, lower sustained swimming performance, and lower growth rates during the first three weeks post-hatching, as well as higher blood glucose concentrations, than those from cool incubation temperatures (27.5 °C). Hatchlings in warm water temperatures (30 °C) exhibited significantly greater swimming performance than those in cool water temperatures (27 °C). Our results indicated that altering incubation temperatures indirectly influences the survival of loggerhead hatchlings by modifying their swimming performance and growth rates, which may affect hatchling predator-avoidance capability. Moreover, thermal manipulation may alter the incubation period, exposing hatchling to water temperatures that they would not otherwise normally experience, which may affect swimming performance. Our results suggest that such conservation strategies may influence their survival, and thus should be carefully considered.