Alternate oscillations of Martian hydrogen and oxygen upper atmospheres during a major dust storm.

Dust storms on Mars play a role in transporting water from its lower to upper atmosphere, seasonally enhancing hydrogen escape. However, it remains unclear how water is diurnally transported during a dust storm and how its elements, hydrogen and oxygen, are subsequently influenced in the upper atmosphere. Here, we use multi-spacecraft and space telescope observations obtained during a major dust storm in Mars Year 33 to show that hydrogen abundance in the upper atmosphere gradually increases because of water supply above an altitude of 60 km, while oxygen abundance temporarily decreases via water ice absorption, catalytic loss, or downward transportation. Additionally, atmospheric waves modulate dust and water transportations, causing alternate oscillations of hydrogen and oxygen abundances in the upper atmosphere. If dust- and wave-driven couplings of the Martian lower and upper atmospheres are common in dust storms, with increasing escape of hydrogen, oxygen will less efficiently escape from the upper atmosphere, leading to a more oxidized atmosphere. These findings provide insights regarding Mars' water loss history and its redox state, which are crucial for understanding the Martian habitable environment.

Strategy for improving the prognosis of patients with intrahepatic cholangiocarcinoma by surgical treatment†:†Considerations based on experience and a literature review.

The prognosis of patients with intrahepatic cholangiocarcinoma (ICC) is still poor, and the 5-year survival rate in patients undergoing radical surgery (R0) is less than one-third. Since the prognosis depends mainly on tumor factors, so early diagnosis is necessary. To extend the survival time of these patients with a poor prognosis, cases of long-term survival were examined based on the results of our experiences and the literature. It was found that the hepatitis virus was highly involved in the carcinogenesis of ICC, and patients who were infected with hepatitis virus had rather good survival. J. Med. Invest. 68 : 15-21, February, 2021.

Spectrally blue hydrated parent body of asteroid (162173) Ryugu.

Ryugu is a carbonaceous rubble-pile asteroid visited by the Hayabusa2 spacecraft. Small rubble pile asteroids record the thermal evolution of their much larger parent bodies. However, recent space weathering and/or solar heating create ambiguities between the uppermost layer observable by remote-sensing and the pristine material from the parent body. Hayabusa2 remote-sensing observations find that on the asteroid (162173) Ryugu both north and south pole regions preserve the material least processed by space weathering, which is spectrally blue carbonaceous chondritic material with a 0-3% deep 0.7-µm band absorption, indicative of Fe-bearing phyllosilicates. Here we report that spectrally blue Ryugu's parent body experienced intensive aqueous alteration and subsequent thermal metamorphism at 570-670 K (300-400 °C), suggesting that Ryugu's parent body was heated by radioactive decay of short-lived radionuclides possibly because of its early formation 2-2.5 Ma. The samples being brought to Earth by Hayabusa2 will give us our first insights into this epoch in solar system history.

High-resolution imaging detector using five microchannel plates and a resistive anode encoder.

We have developed a high-resolution imaging detector with five microchannel plates (MCPs) in a set of V and Z stacks and a resistive anode encoder (RAE) for future space applications. In a position-sensitive system with a RAE, the spatial resolution depends on the signal-to-noise ratios at the anode terminals. Therefore, a high and stable electron gain of MCPs allows the position determination of each photoelectron event with a high spatial resolution. We investigated the effect of the potentials applied to the detector on the pulse height distribution (PHD) and the spatial resolution by means of calculations and experiments. The calculations showed that the negative interstack potential reduced the size of the electron cloud at the Z-stack input by approximately 80%. The result suggests that, under such a condition, the Z-stack MCP is operated in the completely saturated mode and exhibits a narrow PHD. On the other hand, in the measurements, applying the negative interstack potential reduced the width of the PHD by approximately 60%. As a result, the spatial resolution of 45 microm, corresponding to 480x480 pixels, was achieved. The results enable us to optimize and apply the technique to future missions.

Large gastric intramural hematoma mimicking a visceral artery aneurysm: a case report.

BACKGROUND: Gastric hematoma is a rare disorder. Here we report a case of a large gastric intramural hematoma mimicking an impending rupture of a visceral artery aneurysm. CASE PRESENTATION: A 60-year-old Japanese woman complained of left flank pain. Computed tomography with intravenously administered contrast agent showed a solid mass of 5 × 5 × 8 centimeter in the left middle abdominal quadrant. On completion of computed tomography, the working diagnosis was an impending rupture of an aneurysm located in a branch of the superior mesenteric artery. Transcatheter arterial embolization was performed, but angiography of the superior mesenteric artery and the inferior mesenteric artery did not indicate extravasation of the contrast agent and we did not observe any aneurysmal structure. We decided to perform surgery. The operational findings revealed that the mass was a gastric intramural hematoma. CONCLUSION: On encountering an intra-abdominal mass found to be attached to a gastric wall, a gastric intramural hematoma should be considered.

Case report of chylous ascites with strangulated ileus and review of the literature.

We describe a case of chylous ascites with strangulated ileus, and review all 22 cases (including our case) of chylous ascites with strangulated ileus reported in the English and Japanese literature. The patient we describe was a 51-year-old woman with medical history of radiotherapy for cervical cancer of the uterus 15 months prior to being admitted to our hospital with abdominal pain after consuming a meal. A computed tomography (CT) scan revealed ascites, expansion of the small intestine, and whirl sign. Laparotomy revealed chylous ascites with an incarcerated internal hernia of the small intestine, which was released without intestinal resection. In our case the postoperative phase was uneventful, and as in the other 21 literature cases reviewed, treatment by either detorsion, release of the incarcerated internal hernia, or incision of the adhesion band without intestinal resection resulted in rapid improvement in the color of the intestine. It is considered that minimally invasive laparoscopic laparotomy should be selected as the treatment of first choice, because the degree of strangulation is slight in cases where chylous ascites is associated with strangulated ileus.

No-touch pylorus-resecting pancreatoduodenectomy can reduce postoperative complications even in low volume center.

PURPOSES: Pancreatoduodenectomy (PD) was performed for 6 periampullary cancer patients by using methods verified by quality randomized controlled trials (RCT) in a low-volume center (LVC). The purpose of this study was to verify the clinical results. METHODS: No-touch pylorus-resecting pancreatoduodenectomy (PrPD), antecolic gastrojejunostomy, pancreatico-jejunostomy with a lost stent tube to the main pancreatic duct, and early removal of a prophylactic drain were performed. RESULTS: The drain could be removed 4 days after operation, and no pancreatic fistula was observed in all cases. Solid food could be started on POD4 after removing the drain. Furthermore, postoperative systemic chemotherapy could be started earlier. CONCLUSION: Although we have only a few PD cases a year in our institution, PD can be conducted safely without complications by using the methods verified by quality RCTs.

Spontaneous rupture of a dissection of the left ovarian artery.

A 53-year-old female was suddenly hospitalized with acute left lateral abdominal pain. There was no history of trauma to the abdomen. She had received no abdominal operation. X-ray showed a soft tissue shadow in the left flank which displaced the bowel shadows medially. Plain abdominal CT showed a left retroperitoneal hematoma. Dynamic abdominal CT showed an outflow of medium from a blood vessel in the hematoma. At laparotomy, the source of bleeding was found to be the left ovarian artery. The ovarian artery was dilated and meandered remarkably. The ovarian artery and vein were ligated proximally and left adenectomy was performed. The patient made an uneventful recovery. Histological examination suggested a spontaneous rupture of a dissection of the left ovarian artery.

[Systemic lupus erythematosus with bilateral salivary gland swelling and clouding of consciousness accompanied by hemophagocytic syndrome--a study of serial determination of serum cytokines].

We investigated changes in various serum cytokines in a case of systemic lupus erythematosus (SLE) accompanied by hemophagocytic syndrome (HPS). The patient, a 15-year-old male, presented in December 1998 with bilateral salivary gland swelling and a history of fever continuing for more than 10 days. After admission, cerebellar ataxia and clouding of consciousness developed. Laboratory examinations revealed leukopenia, thrombocytopenia, high serum LDH and ferritin, hypercytokinemia, and prominent hemophagocytosis in the bone marrow. Given these findings and positive titers of antinuclear antibody, hypocomplementemia, proteinuria and pericarditis, a diagnosis of HPS with associated SLE was made. The patient was treated with high dose methylprednisolone followed by oral prednisolone and cyclosporine. The patient's clinical symptoms, abnormal blood and urine laboratory data consequently improved, and no recurrence of the symptoms has been documented. However, hemophagocytosis in bone marrow recurred with concomitantly increased serum levels of IL-6 and IL-1 beta. This case indicated that aberrant production of these inflammatory cytokines might be involved in HPS in autoimmune disease.

Huge retroperitoneal dedifferentiated liposarcoma presented as acute pancreatitis: report of a case.

A 74-year-old male with abdominal pain was admitted to the emergency room in our hospital. The high value of serum amylase was shown in his blood test. The postcontrast computed tomography (CT) showed the huge retroperitoneal tumor with a thin-walled mass occupying most of the part of the right retroperitoneal space. The tumor spread into the soft tissues around the pancreas; as a result, the duodenum was compressed and the pancreas was displaced to the right side. The irregular pancreatic outline, obliterated peripancreatic fatty tissue and fluid in the left anterior pararenal space were revealed, so acute pancreatitis was diagnosed. The diagnostic biopsy of retroperitoneal tumor was done, and the pathological findings of retroperitoneal mass revealed dedifferentiated liposarcoma. The medical treatment against acute pancreatitis was performed firstly. After the patient recovered from that, the surgical resection of the tumor with the right kidney and right adrenal gland was completed successfully. The patient remained well, without any evidence of recurrence three months after surgery. However, the histology showed dedifferentiated liposarcoma; therefore, postoperative regular examination is necessary.

Outcome of emergency one-stage resection and anastomosis procedure for patients with obstructed colorectal cancer.

PURPOSES: The purpose of this study was to verify the outcome of the emergency one stage resection and anastomosis procedure for patients with obstructed colorectal cancer. METHODS: An emergency one stage resection and anastomosis procedure was performed for 40 patients with obstructive colorectal cancer. The outcome was verified and compared dividing into two groups. 17 patients under the age of 70 in (Group A), 23 patients 70 years and over in (Group B). RESULTS: The operative mortality rate in both groups was 0%. As a result, postoperative complications were not significantly different between the two groups. The overall survival rate after a 5-year period in both groups was 41.8%, regarding all patients and the survival curves for the two groups, was not significantly different. The 5 year survival rate in stage II or III showed no differences between the two groups. CONCLUSION: The one-stage resection and anastomosis of the large bowel could be applied safely to emergency patients, which in turn allows for excellent short-term operative results in both groups mentioned. This particular procedure should be positively enforced, even in elderly patients in their 70's.

Performance of Y2O3∕Al multilayer coatings for the He-II radiation at 30.4 nm.

We briefly report on the performance and stability of periodic multilayer mirrors containing Y(2)O(3) and Al layers designed for normal incidence reflection at the He-II emission line (30.4 nm). We found that Y(2)O(3)∕Al multilayer coatings had higher reflectivity (24.9%) at 30.4 nm and significantly lower reflectivity (1.3%) at 58.4 nm than the conventional coatings such as Mo∕Si. Furthermore, we investigated the temporal stability of the Y(2)O(3)∕Al multilayer coatings. Our sample was kept under vacuum, dry N(2) purge, and normal atmosphere for over three months, and there were no measurable changes in the reflectivity. These results suggest that we can use Y(2)O(3)∕Al multilayer coatings as standard mirrors for the He-II radiation.

Response of mesangial cells to low-density lipoprotein and angiotensin II in diabetic (OLETF) rats.

BACKGROUND: Progression of diabetic nephropathy is closely associated with morphological changes in glomeruli, such as thickening of the glomerular basement membrane, mesangial expansion, and glomerulosclerosis. To elucidate early glomerular events, we compared the mitogenic activity and extracellular matrix production in mesangial cells (MC) isolated from diabetic rats prior to the manifestation of nephropathy and those showing overt nephropathy. This study may help to clarify the mechanisms underlying diabetic nephropathy and provide clues about early therapeutic interventions for preventing or slowing this process. METHODS: Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a chronic model for human type 2 diabetes mellitus, and age-matched control (LETO) rats were used. Glomerular cell numbers, expression of immediate early genes (c-Fos and c-Myc) and proliferating cell nuclear antigen (PCNA), and low-density lipoprotein (LDL) deposition were determined in renal tissue sections from rats aged 15 to 75 weeks. Mesangial cells (MCs) from OLETF rats at two different stages of the disease, that is, young (12- to 14-week-old) OLETF rats (y-OLETF) prior to the manifestation of nephropathy and old (48- to 50-week-old) OLETF rats (o-OLETF) showing nephropathy, were isolated and cultured. After stimulation with native (n-) or oxidized (ox-) LDL or angiotensin II (Ang II), DNA synthesis and extracellular matrix (ECM) production were examined. Cellular expression of LDL/scavenger receptors was analyzed using fluorescence-labeled LDL and binding to 125I-labeled-LDL. RESULTS: The number of cells per glomerular cross section was significantly higher in OLETF rats than in LETO rats between 25 and 65 weeks of age. In OLETF glomeruli, c-Fos, c-Myc, and PCNA were transiently expressed in the early phase. Glomerular LDL deposition increased with the age of OLETF rats. Addition of a low dose of n-LDL (10 microg/mL) to the culture medium significantly stimulated DNA synthesis of y-OLETF MCs, as compared with o-OLETF MCs and LETO MCs (P < 0.05). A high dose of n-LDL (100 microg/mL) caused cytotoxic effects in all cells. Exposure to ox-LDL minimally affected DNA synthesis of OLETF or LETO MCs. LDL receptors and scavenger receptors were predominant in y-OLETF and o-OLETF, respectively. After stimulation with n-LDL and ox-LDL, expression of type I and type III collagen, along with transforming growth factor-beta (TGF-beta), was higher in o-OLETF MCs that in y-OLETF MCs or LETO MCs. Exposure to Ang II markedly induced DNA synthesis and ECM mRNA expression in y-OLETF MCs and o-OLETF MCs, respectively. CONCLUSIONS: These findings indicate that the cell proliferation process precedes the evolution of diabetic glomerulopathy. The responses of OLETF MCs to n-LDL/ox-LDL and Ang II differed depending on the stage of diabetes. In the early phase, MCs were prone to proliferate, whereas in the late stage, MCs, which expressed higher levels of TGF-beta, tended to synthesize ECM. A functional switch in MCs may contribute to the development of glomerulosclerosis in diabetic nephropathy.

Role of membrane-bound heparin-binding epidermal growth factor-like growth factor (HB-EGF) in renal epithelial cell branching.

UNLABELLED: Role of membrane-bound heparin-binding epidermal growth factor-like growth factor (HB-EGF) in renal epithelial cell branching. BACKGROUND: The developing metanephros is characterized by growth and differentiation of the ureteric bud and the surrounding mesenchymal tissue. These processes can be influenced by several growth factors, including epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha). We examined whether another member of the EGF family of growth factors, heparin-binding epidermal growth factor (HB-EGF), might act as a morphogen in renal epithelial tubulogenesis. METHODS: Expression of HB-EGF mRNA and immunoreactive protein were examined in fetal, neonatal and adult rat kidneys. For in vitro studies of tubulogenesis, a rat renal epithelial cell line (NRK52E) stably transfected with proHB-EGF (NRKproHB-EGF) was treated with TPA for 30 minutes, washed with 2 mol/L NaCl to remove soluble HB-EGF trapped by cell surface heparan sulfate proteoglycan and replated onto plastic dishes in the absence of fetal calf serum. In further experiments, NRKproHB-EGF were suspended in a type I collagen gel in serum-free media. RESULTS: Northern blot analysis indicated that HB-EGF was strongly expressed in embryonic rat kidney (embryonic days 18-20) and was still increased in the neonatal kidney (day 10), compared to the low basal levels in adult kidney. Immunohistochemical analysis confirmed that immunoreactive HB-EGF expression in the fetal rat kidney was localized predominantly to the ureteric bud. When NRKproHB-EGF were plated onto plastic substrata, they became progressively flattened and enlarged and exhibited filopoidia. By 10 hours after plating, NRKproHB-EGF began to migrate and subsequently developed cell-cell contact and fully established tubular-like structures. Immunoelectron microscopy revealed that the initial recovery of cellular proHB-EGF was localized predominantly to areas of cell-cell attachment. No tubule-like structures were observed in similarly treated NRK52E cells transfected with the vector alone. In collagen gels, NRKproHB-EGF developed short tubule-like structures in the absence of TPA treatment, but with simultaneous TPA treatment, longer and more arborized structures developed. MMP-1 mRNA and immunoreactive protein increased in the TPA-treated cells, suggesting that protein kinase C-mediated collagenase activity was important for the observed tubulogenesis. However, inhibition of EGF receptor tyrosine kinase with AG 1478 significantly blunted the TPA-induced tubulogenesis by NRKproHB-EGF grown in collagen gels. CONCLUSIONS: These results indicate that membrane-bound HB-EGF can mediate both epithelial cell branching and cell motility. Localization of proHB-EGF to the site of cell-cell contact and development of tubule-like structures in collagen gels suggests that proHB-EGF may be an important morphogen for renal epithelial cells.

Induction of collecting duct morphogenesis in vitro by heparin-binding epidermal growth factor-like growth factor.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the epidermal growth factor family of growth factors, is synthesized as a membrane-an-chored precursor (proHB-EGF) that is capable of stimulating adjacent cells in a juxtacrine manner. ProHB-EGF is cleaved in a protein kinase C-dependent process, to yield the soluble form. It was observed that HB-EGF acts as a morphogen for the collecting duct system in developing kidneys. HB-EGF protein was expressed in the ureteric bud of embryonic kidneys. Cultured mouse ureteric bud cells (UBC) produced HB-EGF via protein kinase C activation. After stimulation with phorbol ester (12-O-tetradecanoylphorbol-13-acetate) or recombinant soluble HB-EGF, UBC cultured in three-dimensional collagen gels formed short tubules with varied abundant branches. When proHB-EGF-transfected UBC were stimulated with 12-O-tetradecanoylphorbol-13-acetate and cultured in collagen gels, they exhibited linear growth, forming long tubular structures with few branches at the time of appearance of proHB-EGF on the cell surface. The structures exhibited a strong resemblance to the early branching ureteric bud of embryonic kidneys. When UBC were cultured in the presence of transforming growth factor-beta and soluble HB-EGF, they formed long tubules and few branches, similar to the structures observed in proHB-EGF-transfected UBC. These cells exhibited apical-basolateral polarization and expression of the water channel aquaporin-2. These findings indicate that soluble HB-EGF and proHB-EGF induce branching tubulogenesis in UBC in different ways. Juxtacrine activation by proHB-EGF or the synergic action of soluble HB-EGF with transforming growth factor-beta is important for well balanced morphogenesis of the collecting duct system.