Comprehensive Molecular Dynamics Study of Oxygen Diffusion in Carbon Mesopores: Insights for Designing Fuel-Cell Catalyst Supports.

Mesoporous carbon is often used as a support for platinum catalysts in polymer electrolyte fuel-cell catalyst layers. Mesopores in the carbon support improve the performance of fuel cells by inhibiting the adsorption of ionomer onto the catalyst particles. However, the mesopores may impair mass transport. Hence, understanding molecular behaviors in the pores is essential to optimizing the mesopore structures. Specifically, it is crucial to understand the oxygen transport in the high-current region. In this study, the diffusion coefficients of oxygen molecules in carbon mesopores were calculated for various pore lengths, pore diameters, filling rates, and water contents in the ionomer via molecular dynamics simulations. The results show that oxygen diffusion slows by 2 orders of magnitude because of pore occlusion, and it slows down by an additional 1 or 2 orders of magnitude if ionomers are present in the pores. The occlusion can be theoretically predicted by considering the surface free energy. This theory provides some insight into mesoporous carbon designs; for instance, the theory suggests that narrow pores should be shortened to prevent occlusion. Slow diffusion in the presence of ionomers was attributed to the localization of oxygen at the dense ionomer-carbon interface. Thus, to improve oxygen transport properties, carbon surfaces and ionomer structures may be designed in such a manner as to prevent densification at the interface.

Histopathology of fused triplet placenta in rat.

A fused triplet placenta was observed in a Wistar Hannover rat on gestation day 15. Each placenta (referred to as PL-A, PL-B, and PL-C) of this fused placenta was attached to one fetus each, but their fetal weights were lower than that of the fetus attached to the only normal placenta (referred to as PL-N) in this dam. Histopathologically, thinning of the trophoblastic septa and dilatation of the maternal sinusoid in the labyrinth zone were observed in PL-B and PL-C, but not in PL-A or PL-N. The points of placental fusion were at the junctional zone derived from each side of the placenta without connective tissues, and the septum was composed of trophoblastic giant cells. Although PL-A had a solitary metrial gland, PL-B and PL-C shared one metrial gland with one spiral artery terminus branching towards each labyrinth zone.

Effects of cyclophosphamide on rat placental development.

We examined the morphological effects of cyclophosphamide (CPA) on placental development in pregnant rats. CPA was administered as a single dose to pregnant rats intraperitoneally at 0 mg/kg (the control group), 25 mg/kg on gestation day (GD) 12 (the CPA GD 12-treated group), and 25 mg/kg on GD 14 (the CPA GD 14-treated group). The fetal and placental weight decreased in the CPA-treated groups, complete fetal resorption from GD 17 onwards in the CPA GD 12-treated group, and external malformations in the CPA GD 14-treated group. Histopathologically, CPA induced apoptosis and/or cell proliferation inhibition in each part of the placenta. In the labyrinth zone, syncytiotrophoblasts were selectively reduced, resulting in a small placenta. In the basal zone, the number of spongiotrophoblasts was reduced, resulting in hypoplasia of glycogen cell islands. In addition, a small number of interstitial trophoblasts invaded the metrial gland from the basal zone on GD 15. The severity of these lesions was higher in the CPA GD 12-treated group than in the CPA GD 14-treated group. In the metrial gland, although the number of uterine natural killer cells was reduced, metrial gland development was not affected.

Effects of testosterone on rat placental development.

We investigated the morphological effects of testosterone on placental development in a rat model of polycystic ovarian syndrome (PCOS). Testosterone propionate (TP), which was subcutaneously administered to pregnant rats with 5 mg/animal from gestation day (GD) 14 to GD 18, induced a maternal weight reduction without mortality or clinical signs from GD 19 onwards. A decrease in fetal and placental weight, an increase in intrauterine growth retardation (IUGR) rates, and histological changes in the placenta were observed on GD 21 but not on GD15 or 17. Histopathologically, on GD 21, the trophoblast septa thickened, and the maternal sinusoids were narrowed in the labyrinth zone, resulting in a small placenta. Additionally, the placental weight, thickness, and histological morphology in the labyrinth zone on GD 21 in the TP-treated group were nearly identical to those on GD 17 in the control and TP-treated groups. Therefore, it was assumed that the testosterone-induced small placenta was induced in association with the developmental inhibition of the fetal part of the placentas from GD 17 onwards.

Spontaneous seminoma in medaka (Oryzias latipes).

Although spontaneous development of seminoma is rare in medaka, we encountered spontaneous testicular tumors located within the abdominal cavity in two adult medakas. The growth patterns of the tumors were a combination of solid and cord arrangements in one of the two cases (Case I) and lobular in the other case (Case II). The tumor cells resembled the cells at different stages of spermatogenesis, and a small number of oocyte-like cells were also scattered within the tumor. The tumor with solid and cord patterns showed loss of normal testicular architecture, and the tumor cells had partly invaded the dorsal muscular tissue and metastasized to the liver, kidney, and eye. The tumor with a lobular pattern did not exhibit local invasion or metastasis. The tumors were diagnosed as seminomas based on their histopathological characteristics, and the tumor in Case I was observed to be more malignant than that in Case II.

[A Case of Noninvasive Ductal Carcinoma Arising in Benign Phyllodes Tumor].

A 70-year-old woman underwent a partial mastectomy with preoperative diagnosis of phyllodes tumor. Histopathological examination of the resected specimen revealed noninvasive ductal carcinoma of up to 20 mm in the phyllodes tumor. We note the possibility of a situation in which a phyllodes tumor is accompanied by cancer, and detailed pathological examination is necessary.

A case report of RccHanTM: WIST rat with multiple neoplastic and non-neoplastic proliferative lesions.

It is extremely rare to have multiple spontaneous proliferative lesions in young adult rats. Here, we report the occurrence of different proliferative lesions in multiple tissues of a 7-week-old female rat in a 1-week repeated toxicity study. Grossly, multiple white patches and nodules in the bilateral kidneys, femoral and subcutaneous masses, and a nodule in the liver were observed. Renal lesions were diagnosed as renal mesenchymal tumors. One of the femoral subcutaneous masses was diagnosed as an adenolipoma consisting of mammary epithelial cells and mature adipocytes. The other femoral and abdominal subcutaneous masses were diagnosed as lipomas consisting of mature adipocytes. The liver nodule was diagnosed as non-regenerative hepatocellular hyperplasia, which was characterized by the proliferation of slightly hypertrophic hepatocytes. In the cauda equina, the growth of enlarged Schwann cells around the axon was observed, and this lesion was diagnosed as a neuroma.

Comparison of acute inhalation toxicity of sulfuric acid by the inhalation and intratracheal instillation methods.

Recently, intratracheal instillation has been focused on as a simple, low-cost alternative to the inhalation method. In this study, intratracheal instillation of sulfuric acid, a typical acidic compound, was performed to compare the acute toxicity of acidic compounds that could cause damage to the respiratory system between intratracheal instillation and inhalation. Sulfuric acid was administered to male rats at doses of 0.7, 2, 7, 20, and 60 mg/kg by dividing the total dose into four doses. General condition and body weight were examined up to 14 days after administration, and macropathological and histopathological examinations were performed. The half-lethal dose was then estimated. All animals administered 20 and 60 mg/kg sulfuric acid and one animal administered 2 mg/kg sulfuric acid died within 4 h after administration. No abnormalities were observed in other animals. At 20 and 60 mg/kg, multiple red foci or diffuse red areas were macroscopically observed in the lungs. In these lesions, histopathologically, clefts between the mucosal epithelium and basement membrane and necrosis of the alveolar epithelium were observed. Deaths in these groups may have resulted from lung injury. No notable changes were observed in other animals. Therefore, the half-lethal dose of sulfuric acid by intratracheal instillation was estimated as 7-20 mg/kg. The acute toxicity by intratracheal instillation was evaluated with two-fold sensitivity since the exposure at the half-lethal sulfuric acid concentration in inhalation studies was calculated as 43.2 mg/kg.

[A Case of Unresectable Colorectal Cancer with Complete Remission after Palliative Surgery Due to Continued Pharmacotherapy].

A 50s-year-old man was admitted to our hospital because of abdominal pain and vomitting. CT showed a thickened wall of the sigmoid colon, marked enlargement of the oral side, and a 30 mm tumor on the left lateral section of the liver. We diagnosed colonic obstruction due to sigmoid colon cancer with liver metastasis. We failed to place a colonic stent for decompression, so we performed a colostomy using the cecum. An exploratory laparoscopy was performed instead of curative surgery due to peritoneal disseminations, followed by chemotherapy and molecular targeted therapy. Although primary lesion, liver metastatic lesion and disseminated lesions were reduced by pharmacotherapy the patient developed a grade 2 skin disorder around the colostomy. Therefore, it was determined that molecular targeted therapy could not be continued. The resection of the primary lesion and closure of the colostomy were performed to continue pharmacotherapy. Pharmacotherapy was resumed after operation. The patient is currently getting complete remission, undergoing maintenance therapy with no skin disorders. In this case, surgery was performed as part of the multidisciplinary treatment. It suggested that palliative surgery might be an effective option in multidisciplinary treatment.

[A Case of Intussusception Due to Ileal Malignant Lymphoma of AYA Generation].

The case is a 17-year-old man. He had complained of right lower abdominal pain for a week. He had no symptoms such as fever, weight loss, or night sweats. He was diagnosed with intussusception by abdominal contrast-enhanced CT and was hospitalized. The day after hospitalization, lower gastrointestinal endoscopy was performed, and a tumor 25 mm in size was found in the invagination of the ileum. Intussusception was recovered by intestinal scope insufflation, and the tumor was found to be a type 1 tumor located approximately 5 cm proximal to the Bauhin's valve. On day 17 of hospitalization, he had intussusception again at the time of surgery, and performed laparoscopic reduction before performing laparoscopy-assisted partial resection of the small intestine and appendectomy. The postoperative course was good and he was discharged on POD12(on day 29 of hospitalization). Histopathological diagnosis was diffuse large B-cell lymphoma(DLBCL), and chemotherapy was to be administered at the referral hospital. In intussusception of the adolescents and young adults(AYA)generation, such as this case outside of childhood, it is necessary to treat the patient with consideration for the presence of neoplastic lesions such as malignant lymphoma. We report our case with some literature considerations.

Sequential histological changes in the liver of medaka exposed to methylazoxymethaol acetate.

We performed a medaka bioassay for the carcinogenicity of methylazoxymethaol acetate (MAM-Ac) to examine the sequential histological changes in the liver from 3 days after exposure until tumor development. The medaka were exposed to MAM-Ac at a concentration of 2 ppm for 24 hours, and were necropsied at 3, 7, 10, 14, 21, 28, 35, 42, 49, 60, and 91 days after exposure. MAM-Ac induced four cases of hepatocellular adenoma and one case of hepatocellular carcinoma in 8 fish after 60 or 91 days of exposure. Histological changes in the liver until tumor development were divided into three phases. In the cytotoxic phase (1-10 days), MAM-Ac-exposed hepatocytes showed vacuolar degeneration and underwent necrosis and apoptosis, resulting in multiple foci of hepatocyte loss. In the repopulation phase (14-35 days), the areas of hepatocyte loss were filled with hepatic cysts and the remaining hepatocytes were surrounded by hepatic stellate-like cells (or spindle cells) and gradually disappeared. In the proliferation phase (42-91 days), the original hepatic parenchyma was regenerated and progressively replaced by regenerative hyperplastic nodules and/or liver neoplasms. The medaka retained a strong hepatocyte regenerative ability in response to liver injury. It is considered that this ability promotes the proliferation of initiated hepatocytes in multistep carcinogenesis and influences the development of liver tumor over a short period in medaka.

[A Case of Effective Peritoneo-Venous Shunt for Refractory Malignant Ascites in a Gastric Cancer Patient with Peritoneal Dissemination].

This paper reports a case of refractory ascites in a patient with gastric cancer. A peritoneo-venous shunt(PVS)was inserted in the patient, which contributed to extending the duration of home-based care as well as improving the patient's quality of life. The patient was a female in her 70s. She was diagnosed with gastric cancer and underwent total gastrectomy. Five years and 7 months after the surgery, she was diagnosed with peritoneal recurrence. Ascites temporarily decreased following chemotherapy, but gradually worsened thereafter. Since the patient required frequent puncture drainage for the ascites, cell-free concentrated ascites reinfusion therapy(CART)was performed. However, on the day prior to the scheduled second course of CART, marked abdominal distension was observed. Therefore, a PVS was inserted. No PVS-associated complications were observed. Following the insertion of the PVS, the patient's abdominal circumference and body weight markedly improved. Best supportive care(BSC)was provided to the patient as she became weak after undergoing several courses of chemotherapy on an outpatient basis. On the other hand, the PVS was working properly. The patient was able to continue her daily life activities at home. She died from the cancer after 164 days of the PVS insertion.

[A Case of Rectal Cancer with Collet-Sicard Syndrome].

The case was a woman in her 50s. Total pelvic resection was performed for advanced rectal cancer(cT4b[vagina]N3M0, cStage Ⅲc), after neoadjuvant chemoradiation therapy. Five months after the operation, she was unable to stand due to severe back pain. Spinal MRI revealed multiple bone metastases and lumbar fractures. In addition, dysphagia and dysarthria rapidly progressed almost simultaneously with back pain. Initially, brain metastasis was suspected, but head MRI revealed Collet-Sicard syndrome due to skull base metastasis. Irradiation to the skull base and high cervical spine, thoracolumbar spine was started. After irradiation, her back pain and cranial nerve symptoms improved. She was discharged and received palliative treatment. About a month after discharge, she was hospitalized for recurrent dysphagia and died on day 5 of hospitalization. Collet-Sicard syndrome is caused by damage to the cranial nerves Ⅸ to Ⅻ and is often caused by a tumor. Trauma, vasculitis, and internal carotid artery dissection have been reported as other causes. Symptoms such as hoarseness, dysarthria, tongue atrophy, dysphagia, and headache have been reported. Collet-Sicard syndrome due to bone metastasis of colorectal cancer were very rare, and we found only one other report. We report our case with some literature considerations.

[A Case of Rapidly Growing Breast Spindle Cell Carcinoma].

We report a case of rapidly growing breast spindle cell carcinoma. The case was a 69-year-old female. Her chief complaint was right breast pain. She was being followed after surgery for left breast cancer but was seen because of right breast pain. In the right mammary gland CD area, a 27×27 mm large unclear mass lesion was observed, which had not been seen half a year prior. Right mastectomy and axillary dissection were performed following a preoperative diagnosis of pT2N1M0, pStage ⅡB ductal carcinoma. Currently, 2 years and 2 months have passed since the operation, and recurrence has not been observed. Case reports of rapidly growing breast spindle cell carcinoma are occasionally found, but no literature specifically defines acute growth. Here, we defined rapid growth using the tumor doubling time(DT)proposed by Gerstenberg et al. Of all the reported cases of breast spindle cell carcinoma, the DT was fewer than 90 days in most cases. Breast spindle cell carcinoma demonstrates rapid grown compared to normal breast cancer.

The effects of ß-naphthoflavone on rat placental development.

The morphological effects of ß-naphthoflavone (ß-NF) on placental development in pregnant rats were examined. ß-NF, administered to pregnant rats intraperitoneally at 15 mg/kg bw from gestation day (GD) 9 to GD 14, had no effect on maternal body weight gain, mortality, or clinical sign. In the ß-NF-exposed rats, intrauterine growth retardation (IUGR) rates increased on GDs 17 and 21, although there was no effect on fetal mortality rate, fetal or placental weight, or external fetal abnormality. Histopathologically, ß-NF induced apoptosis and inhibition of cell proliferation of the trophoblastic septa in the labyrinth zone, resulting in its poor development. In the basal zone, ß-NF induced spongiotrophoblast apoptosis and delayed glycogen islet regression, resulting in their cystic degeneration. ß-NF-induced CYP1A1 expression was detected in the endothelial cells of the fetal capillaries in the labyrinth zone and in the endothelial cells of the spiral arteries in the metrial gland, but not in any trophoblasts. This indicates that CYP1A1 is inducible in the endothelial cells of the fetal capillaries in the labyrinth zone, and that these cells have an important role in metabolizing CYP1A1 inducers crossing the placental barrier.

Pterobreathers in a model for a layered crystal with realistic potentials: Exact moving breathers in a moving frame.

In this article we perform a thorough analysis of breathers in a one-dimensional model for a layered silicate for which there exists fossil and experimental evidence of moving excitations along the close-packed lines of the K^{+} layers. Some of these excitations are likely breathers with a small energy of about 0.2 eV as the numerically obtained breathers described in the present model. Moving breathers as exact solutions of the dynamical equations are obtained at the price of being generically associated with a plane wave, a wing, with finite amplitude, although this amplitude can be very small. We call them pterobreathers. For some frequencies the wings disappear and the solutions become exact moving breathers with no wings, showing the phenomenon of supertransmission of energy. We perform a theoretical analysis of pterobreathers in systems with substrate potential and show that they are characterized by a single frequency in the moving frame plus the frequency of the wings. We have also studied high-energy stationary breathers which transform into single and double kinks and stable multibreathers with very strong localization.

Spironolactone in Combination with α-glycosyl Isoquercitrin Prevents Steatosis-related Early Hepatocarcinogenesis in Rats through the Observed NADPH Oxidase Modulation.

Administration of the diuretic, spironolactone (SR), can inhibit chronic liver diseases. We determined the effects of SR alone or in combination with the antioxidant α-glycosyl isoquercitrin (AGIQ) on hyperlipidemia- and steatosis-related precancerous lesions in high-fat diet (HFD)-fed rats subjected to a two-stage hepatocarcinogenesis model. Rats were fed with control basal diet or HFD, which was administered with SR alone or in combination with an antioxidant AGIQ in drinking water. An HFD increased body weight, intra-abdominal fat (adipose) tissue weight, and plasma lipids, which were reduced by coadministration of SR and AGIQ. SR and AGIQ coadministration also reduced hepatic steatosis and preneoplastic glutathione S-transferase placental form-positive foci, in association with decrease in NADPH oxidase (NOX) subunit p22phox-positive cells and an increase in active-caspase-3-positive cells in the foci. Hepatic gene expression analysis revealed that the coadministration of SR and AGIQ altered mRNA levels of lipogenic enzymes ( Scd1 and Fasn), antioxidant-related enzymes ( Catalase), NOX component ( P67phox), and anti-inflammatory transcriptional factor ( Pparg). Our results indicated that SR in combination with AGIQ had the potential of suppressing hyperlipidemia- and steatosis-related early hepatocarcinogenesis through the reduced expression of NOX subunits.

Short Leukocyte Telomere Length Precedes Clinical Expression of Atherosclerosis: The Blood-and-Muscle Model.

RATIONALE: Short telomere length (TL) in leukocytes is associated with atherosclerotic cardiovascular disease (ASCVD). It is unknown whether this relationship stems from having inherently short leukocyte TL (LTL) at birth or a faster LTL attrition thereafter. LTL represents TL in the highly proliferative hematopoietic system, whereas TL in skeletal muscle represents a minimally replicative tissue. OBJECTIVE: We measured LTL and muscle TL (MTL) in the same individuals with a view to obtain comparative metrics for lifelong LTL attrition and learn about the temporal association of LTL with ASCVD. METHODS AND RESULTS: Our Discovery Cohort comprised 259 individuals aged 63±14 years (mean±SD), undergoing surgery with (n=131) or without (n=128) clinical manifestation of ASCVD. In all subjects, MTL adjusted for muscle biopsy site (MTLA) was longer than LTL and the LTL-MTLA gap similarly widened with age in ASCVD patients and controls. Age- and sex-adjusted LTL (P=0.005), but not MTLA (P=0.90), was shorter in patients with ASCVD than controls. The TL gap between leukocytes and muscle (LTL-MTLA) was wider (P=0.0003), and the TL ratio between leukocytes and muscle (LTL/MTLA) was smaller (P=0.0001) in ASCVD than in controls. Findings were replicated in a cohort comprising 143 individuals. CONCLUSIONS: This first study to apply the blood-and-muscle TL model shows more pronounced LTL attrition in ASCVD patients than controls. The difference in LTL attrition was not associated with age during adulthood suggesting that increased attrition in early life is more likely to be a major explanation of the shorter LTL in ASCVD patients. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02176941.