Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth.

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Images from the surface of asteroid Ryugu show rocks similar to carbonaceous chondrite meteorites.

The near-Earth asteroid (162173) Ryugu is a 900-m-diameter dark object expected to contain primordial material from the solar nebula. The Mobile Asteroid Surface Scout (MASCOT) landed on Ryugu's surface on 3 October 2018. We present images from the MASCOT camera (MASCam) taken during the descent and while on the surface. The surface is covered by decimeter- to meter-sized rocks, with no deposits of fine-grained material. Rocks appear either bright, with smooth faces and sharp edges, or dark, with a cauliflower-like, crumbly surface. Close-up images of a rock of the latter type reveal a dark matrix with small, bright, spectrally different inclusions, implying that it did not experience extensive aqueous alteration. The inclusions appear similar to those in carbonaceous chondrite meteorites.

Thrombotic thrombocytopenic purpura associated with polyarteritis nodosa.

We present a case of classical polyarteritis nodosa (PN) overlapping thrombotic thrombocytopenic purpura (TTP). A 70-year-old woman was transferred to our hospital because of general fatigue and fever. On admission, laboratory findings revealed leukocytosis, normochromic normocytic anemia and renal dysfunction. About one week later, she developed disturbance of consciousness, and laboratory findings revealed rapidly progressive thrombocytopenia and renal dysfunction. We suspected the presence of microscopic polyangiitis (MPA), based on mild elevation of myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibody (ANCA). On post-admission Day 11, renal biopsy was performed but the diagnosis of MPA could not be confirmed because of the absence of glomerular crescent formation or vasculitis. However, the biopsy specimen showed many collapsed glomeruli and interstitial inflammation, indicating the presence of occlusive lesions, such as vasculitis in larger arteries. We instituted methylprednisolone pulse therapy, cyclophosphamide and plasma exchange, because the clinical symptoms also satisfied the criteria of TTP. Despite the intensive treatment, the patient died on 43rd day of hospitalization due to thalamic hemorrhage. Autopsy showed typical findings of classical PN including disruption of arterial walls and fibrinoid necrosis in the medium-sized arteries of the kidneys and colon. We detected reduced activity of von Willebrand factor-cleaving protease (VWF-CP) and the presence of plasma inhibitory IgG against VWF-CP. A better understanding of the mechanisms would be useful.

Evaluation of lipid peroxidation of human erythrocyte hemolysates.

Lipid peroxidation of human erythrocyte hemolysates was evaluated by determining thiobarbituric acid reactive substance by fluorospectrophotometer. Because of the non-linear relationship between malondialdehyde formation and hemoglobin concentration, a constant hemoglobin concentration is required to obtain reproducible results. Disruption of the hemolysate by sonication and the presence of formed elements are necessary to induce the reaction, the optimal pH of which was found to be limited to the region of 7.4. Either ferric or ferrous ions are essential for the reaction to proceed, but if both are present, their catalytic activity is abolished. The present method will be useful in the investigation of the mechanism of oxidative damage to erythrocytes under various pathological conditions.

Asymmetric synthesis of the core structure of (-)-CP-263,114.

The enantioselective construction of a fully functionalized core structure of (-)-CP-263,114 (1), containing most of the required functionality for total synthesis, was conducted through sequential radical fragmentation-reductive olefination.

Cerebral ischemia as a causative mechanism for rapid progression of brain atrophy in chronic hemodialysis patients.

BACKGROUND: It has been found that brain atrophy develops more rapidly in patients with end-stage renal failure after initiation of dialysis therapy. The present study was designed to analyze the relationship between brain atrophy and asymptomatic ischemic brain lesions. PATIENTS AND METHODS: Magnetic resonance imaging (MRI) was performed for the evaluation of brain atrophy and ischemic lesions. Brain atrophy was assessed by the ventricular-brain ratio (VBR), calculated as the ratio of the ventricular area to the whole brain area on the maximum MRI slice. The severity of periventricular hyperintensity (PVH) and the number of lacunae were also regarded as ischemic brain lesions. Fifty-five patients undergoing maintenance hemodialysis (HD) without clinically overt neurological signs and symptoms, with a mean age of 52 +/- 11 (SD) years and a mean HD duration of 7 +/- 6 (SD) years were subjected. VBR and its relationship to ischemic brain lesion data were compared to those in 35 non-HD patients (controls), with a mean age of 42 +/- 14 (SD) years. RESULTS: The VBR, the number of lacunae and the severity of PVH tended to increase with age in HD. The VBRs at all age groups were significantly higher in HD than in controls (7.0 vs 3.7% at the 4th decade, p < 0.05; 8.4 vs 5. 9% at the 5th decade, p < 0.05; 9.6 vs 5.4% at the 6th decade, p < 0.05; and 11.6 vs 6.3% at the 7th decade, p < 0.05). HD patients had significantly higher number of lacunae and had more advanced PVH than did controls. Both the number of lacunae and the severity of PVH were significantly correlated to VBR in HD. CONCLUSION: In conclusion, the rapid progression of brain atrophy was related to the asymptomatic ischemic brain lesions in our HD patients. Such data indicated that cerebral ischemia might be a causative mechanism of brain atrophy in chronic hemodialysis patients.

Acyclovir-resistant herpes zoster encephalitis successfully treated with vidarabine: a case report.

A 78-year-old man developed herpes zoster virus (HZV) encephalitis. Initially, treatment with aciclovir (750 mg per day) improved CSF cell count and protein level. During the treatment, however, encephalitis in the patient deteriorated in spite of the treatment with aciclovir, suggesting that HZV in the patient had become resistant to aciclovir. Subsequent treatment with vidarabine (600 mg per day, for 15 days) resulted in dramatic improvement in CSF pleocytosis. About two months after the discontinuation of vidarabine, the CSF cell count was normal. The patient became alert gradually, but his amnestic syndrome remained unchanged. Vidarabine may be recommended in the treatment of HZV encephalitis when aciclovir is not effective.

[Idiopathic chronic tubulointerstitial nephritis].

Chronic tubulointerstitial nephritis is a chronic disorder that primarily affects the renal tubules and interstitium while sparing the glomeruli and vasculature. Although there are variable underlying causes, 10% to 25% of the cases of chronic tubulointerstitial nephritis are entirely idiopathic. A thorough search for the underlying causes of chronic tubulointerstitial nephritis is especially important because to avoid or to correct such underlying causes may prevent progression or even allow for some reversal of renal failure. Thus, diagnosis of idiopathic form of chronic tubulointerstitial nephritis is carefully made after the exclusion of potential underlying causes. The major pathologic features of idiopathic chronic tubulointerstitial nephritis are 1) interstitial fibrosis, 2) tubular atrophy and 3) infiltration of the parenchyma with mononuclear inflammatory cells. Of these three features, the extent of interstitial fibrosis is significantly correlated with decreased glomerular filtration rate and progression rate of renal failure. Idiopathic chronic tubulointerstitial nephritis seems to be slowly progressive and develop to end stage renal failure. Since there is no specific treatment for idiopathic chronic tubulointerstitial nephritis, avoidance and correction of exacerbation factors are essential for progression to renal failure. It is acceptable that protein-restricted diet be applied to idiopathic chronic tubulointerstitial nephritis although its effects on the disease still remain equivocal.

[A clinical study of pulmonary edema on paraquat poisoning by double indicator dilution method using heat and sodium].

We studied the formation of pulmonary edema on 9 patients with paraquat poisoning using thermal-sodium double indicator dilution method for the measurement of lung water. In survivors group (n = 4) extravascular thermal volume (EVTV) was not almost changes. In non-survivors group (n = 5) EVTV increased about three times as much as that in survivors group on 32 hours after admission. EVTV was correlated with PCP-PCOP in both survivors group and non-survivors group (n = 64, r = 0.665, p less than 0.01). But EVTV in non-survivors group was higher than that in survivors group within same PCP-PCOP. In non-survivors group delta EVTV/delta (PCP-PCOP) in 24 hours after admission was correlated with initial PCP-PCOP (r = 0.984, p less than 0.01). We propose that the formation of pulmonary edema on paraquat poisoning is mainly due to the increased capillary permeability, influenced by the increased pressure gradient of capillary barrier.

Metabolism in vivo of the tropane alkaloid, scopolamine, in several mammalian species.

1. In vivo metabolism of scopolamine was studied in rats, mice, guinea pigs and rabbits. The structures of eight urinary metabolites including unchanged drug were elucidated by mass and nuclear magnetic resonance spectrometry. Determination of these metabolites was achieved by a g.l.c. method using a semi-capillary column. 2. The major metabolites in rats were the three phenolic metabolites, p-hydroxy-, m-hydroxy- and p-hydroxy-m-methoxy-scopolamine. 3. Significant intra-species difference of the metabolism was observed in rabbits. Tropic acid was the major metabolite in two rabbits out of three, while the other rabbit excreted mainly unchanged scopolamine, accompanied by five metabolites. Tropic acid was also the major metabolite in guinea pigs, but was of minor importance in mice. 4. The dehydrated metabolites, aposcopolamine and aponorscopolamine, were abundantly excreted in guinea pigs, moderately in mice, and least in rabbits and rats. 5. Excretion of glucuronide conjugates of scopolamine and norscopolamine were high in mice compared with other species. On the other hand, phenolic metabolites in rat urine; and tropic acid in rabbit and guinea pig urine, were excreted as the free forms. 6. These results indicate that scopolamine metabolism is highly species-specific.

Metabolic fate of fenetylline in rat and man.

1. Metabolic fate of 7-[2-(alpha-methylphenylethylamino)ethyl]theophylline hydrochloride (fenetylline) was investigated in male Sprague-Dawley rats and three male volunteers. 2. Six metabolites were identified in the rat urine as amphetamine(AP), p-hydroxy-AP, acetylaminoethyl-theophylline(TP), aminoethyl-TP, hydroxyethyl-TP and carboxymethyl-TP by comparison of their spectral properties and h.p.l.c. and g.l.c. characteristics with those of authentic samples. All these metabolites was also detected in the urine of humans receiving fenetylline. 3. Quantification of these metabolites using h.p.l.c. and g.l.c. showed that carboxymethyl-TP, p-hydroxy-AP and acetylaminoethyl-TP were the major metabolites in 0-24 h rat urine at 13.7%, 11.2% and 9.3% of dose, respectively. In men, carboxymethyl-TP(39-43% dose) and AP(23-33% dose) were the major metabolites in 0-48 h urine. 4. These results suggest that fenetylline metabolism proceeds via oxidative cleavage at two different sites to produce aminoethyl-TP and AP, respectively. The pathway producing AP predominates, in both man and rat, but is more predominant in the former.

Risk factors for methicillin-resistant Staphylococcus aureus (MRSA) infection in a Japanese geriatric hospital.

A case control study on MRSA infection was carried out, with the purpose of evaluating the effect of age, gender, hypoalbuminemia, the limitation of activities of daily living (ADL), the administration of antibiotics and the use of the new cephems which include third generation cephalosporins and monobactam and carbapenems, on the occurrence of MRSA infection among the inpatients in a geriatric hospital. From April 1991 to March 1994, 285 patients underwent a bacterial culture in the various clinical aspects. 118 patients were positive for MRSA, who were then used as cases while 167 patients who were negative for MRSA were used as controls. The level of serum albumin and the ADL score were lower in the MRSA group than in the non-MRSA group (P < 0.01) while the number of antibiotics administered before bacterial culture was greater in the MRSA group than in the non-MRSA group (P < 0.01). The third generation cephems were more commonly used in the MRSA positive patients than the negative patients (P < 0.01). Even after controlling for the other factors, hypoalbuminemia (OR = 1.73, 95% CI = 1.27-2.36), the limited ADL (partially limited vs without limitation: OR = 1.88, 95% CI = 1.19-2.96, completely limited vs without limitation: OR = 2.50, 95% CI = 1.64-3.82), the use of antibiotics other than the third generation cephems (vs without antibiotics: OR = 1.73, 95% CI = 1.20-2.50) and the administration of the third generation cephems (vs without antibiotics: OR = 3.12, 95% CI = 2.16-4.50) increased the risk of MRSA infection.

Significance of erythrocyte lipid peroxidation and superoxide dismutase activity in a patient with idiopathic pulmonary haemosiderosis.

In a patient with idiopathic pulmonary haemosiderosis, lipid peroxidation of erythrocytes and their superoxide dismutase activity were determined. The latter was found to be decreased, and the erythrocytes showed easy peroxidisability, which was shown by vulnerability to hydrogen peroxide and a marked elevation of iron-catalysed lipid peroxidation in addition to a higher basal malondialdehyde level, an end product of lipid peroxidation. These findings were correlated with haemolysis, iron-deficiency anaemia and a shortened survival of erythrocytes. Although the aetiological significance of our observations still remains to be clarified, it appears that antioxidant enzymes and the peroxidative reactivity of erythrocytes should be carefully evaluated in other patients with idiopathic pulmonary haemosiderosis.

Treatment of hepatic encephalopathy by retrograde transcaval coil embolization of an ileal vein-to-right gonadal vein portosystemic shunt.

A 43-year-old non-cirrhotic woman suffered from encephalopathy caused by an extrahepatic portosystemic shunt between the ileal vein and inferior vena cava via the right gonadal vein. Percutaneous transcatheter embolization with stainless steel coils was performed by the retrograde systemic venous approach. Encephalopathy improved dramatically.