Frustration-induced valence bond crystal and its melting in Mo3Sb7.

(121/123)Sb nuclear quadrupole resonance and muon spin relaxation experiments of Mo_3Sb_7 revealed symmetry breakdown to a nonmagnetic state below the transition recently found at T_S approximately 50 K. The transition is characterized by a distinct lattice dynamics suggested from narrowing of nuclear fields. We point out that the Mo sublattice is a unique three-dimensional frustrated lattice where nearest-neighbor and next-nearest-neighbor antiferromagnetic interactions compete, and propose that tetragonal distortion to release the frustration stabilizes long-range order of spin-singlet dimers, i.e., valence bond crystal, which is thermally excited to the dynamic state with cubic symmetry.

The pseudogap and anisotropic thermal expansion in RMn(4)Al(8) (R = La,Y,Lu and Sc).

The temperature dependence of the magnetic susceptibility shows a broad maximum at ∼550 and 630 K for LuMn(4)Al(8) and ScMn(4)Al(8), respectively, which can be interpreted as due to the presence of a pseudogap in the effective bands as in LaMn(4)Al(8) and YMn(4)Al(8). The anisotropic thermal expansion observed for RMn(4)Al(8) (R = La, Y, Lu and Sc) and the sensitive volume dependence of the gap width throughout the RMn(4)Al(8) system suggest dominant magnetic coupling in Mn spin chains along the c axis.

Improvement of the resonant cavity applicator for brain tumor hyperthermia - Experimental heating results -.

A re-entrant type resonant cavity applicator for deep tumor hyperthermia treatment was presented. In this method, a human body is placed between the gap of the inner re-entrant cylinders, and is heated with electromagnetic fields stimulated in the cavity without contact between the surface of the human body and the applicator. In this paper, two methods to control the heating pattern were proposed. In the first method, a human body was moved towards the electrode. In the second method, the diametric ratio of the inner electrode was changed. The controllable range of heating pattern was about 20% of the distance from the center of the agar phantom in the direction of depth.

Improvement of the resonant cavity applicator for brain tumor hyperthermia - Computer simulation results -.

This paper discusses new methods to control the heating pattern of the prototype resonant cavity applicator for deep tumor hyperthermia treatment. We have already confirmed the effectiveness of the developed heating system with experiments using agar phantoms and computer simulations. Here, the following two methods to control the heating pattern were proposed. In the first method, a human body, which was placed in the gap between the two inner electrodes, was only moved towards the electrode. In the second method, in addition to the first method, the diametric ratio of the inner electrodes was changed. According to our computer simulation of heating agar phantoms, we found that the hot spot was moved about 35% of the distance from the center of the agar phantom. It was found that the proposed heating methods were applicable to both deep and regional hyperthermia treatments.

Invasive Aspergillus stomatitis in patients with acute leukemia: report of 12 cases.

An 8-year retrospective analysis of invasive Aspergillus stomatitis in neutropenic patients with acute leukemia was performed to characterize the epidemiology and clinical features of the infection. Twelve cases of invasive Aspergillus stomatitis were identified with both clinicohistological and microbiological evidence, and the majority of cases were caused by Aspergillus flavus (10 [83%] of 12 patients). The infection was strongly suspected when a neutropenic patient developed persistent fever without a known source, symptoms of gingival pain and facial swelling, and a solitary ulcerating lesion of mucogingiva covered with a gray necrotic pseudomembrane. Aspergillus stomatitis was diagnosed a median 23 days after admission. In all 12 patients, the diagnosis was made during the period of neutropenia. Ten patients (83%) were treated with amphotericin B and surgery and survived with recovery of neutrophils. Two patients died, and disseminated aspergillosis was identified in 1 patient.

Spatially inhomogeneous development of antiferromagnetism in URu2Si2: evidence from 29Si NMR under pressure.

From 29Si NMR study, we present evidence for spatially inhomogeneous development of antiferromagnetic (AF) ordering below T(o) = 17.5 K in URu2Si2. In the pressure range between 3.0 and 8.3 kbar, we have observed the 29Si NMR lines arising from the AF region as well as the previously observed 29Si NMR line which correspond to the nonmagnetic region in the sample. The AF volume fraction is enhanced by applied pressure, whereas the magnitude of internal field at the Si site remains constant (910 Oe) up to 8.3 kbar. In the AF region, the ordered moment is about an order of magnitude larger than 0.03 mu(B)/U.

Synthesis and immunosuppressive activity of 2-substituted 2-aminopropane-1,3-diols and 2-aminoethanols.

A series of 2-substituted 2-aminopropane-1,3-diols was synthesized and evaluated for their lymphocyte-decreasing effect and immunosuppressive effect on rat skin allograft. A phenyl ring was introduced into the alkyl chain of the lead compound 3, which is an immunosuppressive agent structurally simplified from myriocin (1, ISP-I) via compound 2. The potency of the various compounds was dependent upon the position of the phenyl ring within the alkyl side chain. The most suitable length between the quaternary carbon atom and the phenyl ring was two carbon atoms. 2-Substituted 2-aminoethanols were successively synthesized and evaluated for their T-cell-decreasing effect and immunosuppressive effect using a popliteal lymph node gain assay in rats. The absolute configuration at the quaternary carbon affected the activity, and the (pro-S)-hydroxymethyl group of compound 6 was essential for potent immunosuppressive activity. Favorable substituents for the (pro-R)-hydroxymethyl group of 6 were hydroxyalkyl (hydroxyethyl and hydroxypropyl) or lower alkyl (methyl and ethyl) groups. 2-Amino-2-[2-(4-octylphenyl)ethyl]propane-1,3-diol hydrochloride (6, FTY720) was found to possess considerable activity and is expected to be useful as an immunosuppressive drug for organ transplantation.

[Results of antimicrobial susceptibilities of strains clinically isolated at 8 institutions in Hiroshima City to major oral antimicrobial drugs, mainly new quinolone drugs. Hiroshima Levofloxacin Susceptibility Surveillance Group].

To evaluate the resistance for major oral antimicrobial agents, mainly new quinolones, we carried out a drug susceptibility surveillance of 3,050 strains of 11 microbial species clinically isolated at 8 institutions such as general hospitals and examination centers in Hiroshima city. 10 antimicrobial agents were used: 3 new quinolone drugs, 5 beta-lactam drugs, minocycline and clarithromycin. Among Gram-positive bacteria, methicillin resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis showed low susceptibility to the new quinolone drugs, while methicillin susceptible Staphylococcus aureus (MSSA) and Streptococcus pneumoniae were highly sensitive to these drugs. Among Gram-negative bacteria, Pseudomonas aeruginosa showed high resistance for the new quinolone drugs, but enteric bacteria and Haemophilus influenzae did not show marked resistance, maintaining almost good sensitivity to these drugs. To reduce the appearance of resistant bacteria, appropriate antimicrobial agents should be selected. Drug susceptibility surveillance in the community will be also important in the future.

Aspergilloma: comparison of treatment methods and prognoses.

We report five cases of aspergilloma. Three patients had a previous history of tuberculosis, including one who fully recovered after resection of the right lower lobe. Four patients were treated mainly with oral itraconazole. Two of these four patients, died, one of massive hemosputa, and one of heart valve disease, while two had a good outcome, although one of them has since developed respiratory insufficiency and has received oxygen therapy. In itraconazole therapy, the daily dose may be 200 mg or more, and the duration of treatment may be 1 year or more. Percutaneous intracavitary instillation of amphotericin B, performed in one patient, showed no efficacy. The efficacy of this treatment may depend on the width and number of drainage bronchi, and on the mechanism of acceleration of degradation of the fungus ball. It is important to carefully choose the therapy for aspergilloma, with due consideration being given to the patient's pulmonary function and general status.

[Study on antibiotics susceptibility and mechanism of carbapenem-resistance in clinical isolates of Pseudomonas aeruginosa].

The susceptibility of 260 strains of Pseudomonas aeruginosa to several antibiotics and the mechanism of resistance to carbapenems were investigated. The number of strains of P. aeruginosa moderately resistant or resistant to ofloxacin, ceftazidime and imipenem (IPM) were 76 (29.2%), 31 (11.9%) and 30 (11.5%), respectively. There was no clear relationship between the drug resistance of P. aeruginosa and serum type. Fourteen strains (46.6%) out of 30 IPM-resistant strains were susceptible to meropenem (MEPM). Twenty seven (90.0%) IPM-resistant strains showed cross resistant to panipenem (PAPM), and 12 strains (44.4%) out of the 27 strains showed high susceptibility to MEPM. P. aeruginosa becomes resistant to IPM and PAPM only by the decrease in the outer membrane permeability of these carbapenems. In contrast, P. aeruginosa becomes equally resistant to MEPM by concurrent occurrence of the increase in the efflux of the antibiotics and the decrease in the outer membrane permeability of the antibiotics. The possibility that both mechanisms are taken place concurrently in P. aeruginosa is considered to be low, and it was also supported by the results of the present study.

Synthesis and biological evaluation of 2,2-disubstituted 2-aminoethanols: analogues of FTY720.

Desymmerization of symmetric FTY720 by substitution of different alkyl groups for one of the prochiral hydroxymethyl groups was performed. The size of the alkyl groups and the absolute configuration at quaternary carbon were important on immunosuppressive activity.

Periodic fever compatible with familial Mediterranean fever.

A 55-year-old male presented with a recurrent fever of over 38 degrees C, occurring at irregular intervals 1-6 times a month with chest, back or abdominal pain. After admission to our hospital, we found the following characteristics: 1) the febrile attacks were accompanied by obvious inflammatory findings and pleuritis or peritonitis; 2) the patient's elder sister had a similar periodic fever; and 3) there were no apparent causative factors responsible for his symptoms. Therefore, we diagnosed this as a case compatible with familial Mediterranean fever. The febrile attacks have been completely suppressed by daily colchicine. This is the seventh case of familial Mediterranean fever reported in Japan.

[Asporogenic anaerobic empyema--clinical and bacteriological investigations of 31 patients with anaerobic empyema].

The author reviewed the records of 31 patients with asporogenic anaerobic empyema mostly seen in the wards of Internal Medicine, Juntendo University Hospital during the 27 years between 1961 and 1988, and obtained the following results. 1. There were 25 males and 8 females with an average age of 57.8 and 51.0 y/o (range, 25 to 79 y/o), respectively males more than forty years old occupied 74.2 percent of all cases. 28 patients (90%) had underlying conditions. 2. The cases of mixed infections with anaerobes and aerobes were only 22.6%. 3. The isolated bacteria were microaerophilic streptococcus, Bacteroides spp., Peptostreptococcus spp., Fusobacterium spp. etc. in this order. 4. There were no relationships between anaerobic infections with or without aerobes and putrid odor of pleural effusion. 5. Bacteroides spp. were isolated most in the group with putrid pleural effusion, however, they were not isolated in the group without putrid pleural effusion at all. This fact suggests that there is an intimate relationship between putrid odor and Bacteroides spp. 6. There was no deceased case which pleural effusion had been drained sufficiently with open or closed drainage. It suggests that sufficient drainage is the most important in therapeutic procedures of asporogenic anaerobic empyema.

[Eight cases of diphyllobothriasis].

Eight cases of diphyllobothriasis have been experienced in the Juntendo University Hospital. Seven of the 8 patients excreted tapeworm fragments. Eggs of Diphyllobothrium latum were found in the feces in 5 cases. One patient had a history of ingestion of raw trout (Sushi), and 2 raw salmon. One might have been infected in foreign countries, and 3 could not tell the source of infection. Bithoinol was administered orally to 7 patients. Four of the 7 excreted the worm and the scolex was recognized in three of the four. Neither recurrence nor abnormal findings have been recognized so far.

[Fluconazole treatment of systemic mycoses].

Efficacies of fluconazole, a new triazole antifungal agent, were evaluated in 11 cases of systemic mycoses (1 case each of candiduria, pulmonary cryptococcosis, pulmonary aspergillosis, pulmonary penicilliosis and suspected fungal pulmonary infection, and 3 cases each of candidemia and Candida endophthalmitis). The clinical efficacies were excellent or good in 8 out of 9 cases and poor in 1. Side effects observed were mild with 1 incident each of gastrointestinal symptom and reversible leukopenia. This drug appears to be promising in treatment of systemic mycoses.