Dimensional reduction and incommensurate dynamic correlations in the [Formula: see text] triangular-lattice antiferromagnet Ca3ReO5Cl2.

The observation of spinon excitations in the [Formula: see text] triangular antiferromagnet Ca3ReO5Cl2 reveals a quasi-one-dimensional (1D) nature of magnetic correlations, in spite of the nominally 2D magnetic structure. This phenomenon is known as frustration-induced dimensional reduction. Here, we present high-field electron spin resonance spectroscopy and magnetization studies of Ca3ReO5Cl2, allowing us not only to refine spin-Hamiltonian parameters, but also to investigate peculiarities of its low-energy spin dynamics. We argue that the presence of the uniform Dzyaloshinskii-Moriya interaction (DMI) shifts the spinon continuum in momentum space and, as a result, opens a zero-field gap at the Γ point. We observed this gap directly. The shift is found to be consistent with the structural modulation in the ordered state, suggesting this material as a perfect model triangular-lattice system, where a pure DMI-spiral ground state can be realized.

Higher magnetic-field generation by a mass-loaded single-turn coil.

Single-turn coil (STC) technique is a convenient way to generate ultrahigh magnetic fields of more than 100 T. During the field generation, the STC explosively destructs outward due to the Maxwell stress and Joule heating. Unfortunately, the STC does not work at its full potential because it has already expanded when the maximum magnetic field is reached. Here, we propose an easy way to delay the expansion and increase the maximum field by using a mass-loaded STC. By loading clay on the STC, the field profile drastically changes, and the maximum field increases by 4%. This method offers access to higher magnetic fields for physical property measurements.

An in vitro study of the structure-activity relationships of sulfated polysaccharide from brown algae to its antioxidant effect.

In this paper, the structure-activity relationships of chemically modified uronic acid polymer fragments from brown algae with regard to their antioxidant effects on H2O2-damaged lymphocyte were studied. The results indicated that the most potent antioxidant activity was obtained from the sulfated polysaccharide with ratio of mannuronate blocks (M-blocks) to guluronate blocks (G-blocks) of 3 to 1 and carboxyl residue unesterified. The sulfated G-blocks with esterified carboxyl residue also prevented lymphocyte from injury. However, the sulfated G-blocks bearing unesterified carboxyl residue hardly exerted antioxidant activity. These findings suggested that both M-blocks and esterified carboxyl residue were determinant structures in preventing lymphocyte from being oxidized by H202, indicating that the existence of M-blocks was more important in scavenging free radicals.

[Effects of bisphosphonates on vitamin A-induced bone resorption in thyroparathyroidectomized rat].

A bone resorption model in which osteoclasts were selectively activated was made by administering vitamin A--a bone resorption agent--to juvenile thyroparathyroidectomized rat. Inhibition of bone resorption by YM-175--a third generation bisphosphonate--was studied using this model based on bone histomorphometry of the proximal part of the tibia and on biochemical data. Six-week-old male SD rats were thyroparathyroidectomized (TPTX). On the 11th day following TPTX they were treated with vitamin A (etretinate). In the calcitonin group, salmon calcitonin or its vehicle was added, and in the bisphosphonate group, YM-175 or its vehicle was added. They were sacrificed on the 21st day following TPTX. Calcitonin was used to confirm its inhibitory activity of bone resorption in this model. Cancellous bone in the epiphysis was subjected to histomorphometry using tetracycline labeling or TRAP staining, and the number of primary trabeculae at the metaphysis was counted to evaluate bone resorption activity. Serum calcium, phosphorus, urinary calcium, phosphorus, pyridinoline and deoxypyridinoline were measured for biochemical analysis. YM-175 did not change any bone formation parameters in the histomorphometry of the epiphysis, while it significantly decreased resorption parameters both histomorphometrically and biochemically. Primary trabeculae at the metaphysis were found to be longer and denser after administration of YM-175. The effect of YM-175 as a bone resorption inhibitor was observed even in a short duration experiment. There was no damage to mineralization, and no inhibiting effect was observed on bone formation. Similar results were observed by calcitonin. YM-175 was concluded to be an inhibitor of bone resorption caused by vitamin A administration.

A sequence-tagged site map of human chromosome 11.

We report the construction of 370 sequence-tagged sites (STSs) that are detectable by PCR amplification under sets of standardized conditions and that have been regionally mapped to human chromosome 11. DNA sequences were determined by sequencing directly from cosmid templates using primers complementary to T3 and T7 promoters present in the cloning vector. Oligonucleotide PCR primers were predicted by computer and tested using a battery of genomic DNAs. Cosmids were regionally localized on chromosome 11 by using fluorescence in situ hybridization or by analyzing a somatic cell hybrid panel. Additional STSs corresponding to known genes and markers on chromosome 11 were also produced under the same series of standardized conditions. The resulting STSs provide uniform coverage of chromosome 11 with an average spacing of 340 kb. The DNA sequence determined for use in STS production corresponds to about 0.1% (116 kb) of chromosome 11 and has been analyzed for the presence of repetitive sequences, similarities to known genes and motifs, and possible exons. Computer analysis of this sequence has identified and therefore mapped at least eight new genes on chromosome 11.

Highly polymorphic tetramer repeat (GATA)n on human chromosome 11p15.3.

A tetrameric repeat sequence (GATA)n was identified by random DNA sequencing of chromosome 11-specific cosmid clones and located at 11p15.3 by fluorescence in situ hybridization. Oligonucleotide primers flanking the repetitive unit were used to amplify the DNA using the polymerase chain reaction (PCR) and this repetitive element was shown to be highly polymorphic and inherited in typical Mendelian fashion. Analysis of amplification products containing the repetitive element from 45 unrelated Caucasian individuals and five families showed at least five alleles at this locus, ranging from 227 to 249 bases in length. This polymorphism may serve as a useful PCR-detectable genetic marker for 11p15.3, a landmark for disease gene isolation, and a locus for identity testing.

Primary myxoma in the pituitary fossa: case report.

A case of primary myxoma in the pituitary fossa is described. The tumor presented as an intrasellar and suprasellar mass and was successfully removed during a transsphenoidal operation. It was verified as a myxoma by histopathological studies, and there was no evidence that it was a metastasis. This is thought to be the first report of this tumor occurring in the pituitary fossa.

Necrotic changes in prolactinomas after long term administration of bromocriptine.

Six prolactinoma patients were studied endocrinologically and their tumors were examined histologically after long term bromocriptine therapy. In patient 1 with a large prolactinoma, a marked reduction in size and a remarkable decrease in elevated serum PRL levels occurred after bromocriptine treatment for 8 months. The histological findings consisted of two components, i.e. shrunken island-like cell nests and acellular spaces. Some degenerative and necrotic tumor cells, hyaline substance, and fibrosis were observed with light and electron microscopy in these acellular spaces. Island-like cell nests consisted of atrophic cells having disproportionally scanty cytoplasm. The same histological findings were observed in four other patients. However, in another patient whose tumor decreased in size only slightly during bromocriptine therapy, the specimen had few acellular spaces. Thus, long term bromocriptine treatment of patients with prolactinomas may result in necrosis of some adenoma cells in some patients.

[A case of internal carotid dolichoectasia].

A 50-year-old woman noticed right motor and sensory paralysis in the morning of December 15, 1978, which improved gradually to be able to walk during 20 days. She had recurrence of incomplete paralysis of right extremities with speech disturbance and admitted to our department on April 7. Neurological examination revealed right hemiparesis. Plain skull rentogenorgram showed a calcification extending posteriorly from the left anterior clinoid process. CT scan showed a mass lesion located at the left frontal lobe to the ambient cistern. The mass lesion showed high density, but its midportion was isodensity. The left carotid angiogram demonstrated abnormally curved, tortuous and dilated internal carotid artery at the intracavernous portion (C3) to bifurcation (C1). The cerebral circulation time was greatly delayed, which regained about 6 seconds for the visualization of the distal portion of the middle cerebral artery. On the basis of the above, we considered that the first right hemiparesis was due to emboli produced in the dolichoectasia and the following progressive stroke was attributable to the low perfusion demonstrated by a great delay of circulation time. The operation was performed to trap the dolichoectasia after STA-MCA anastomosis. However, trapping procedure was very difficult because of hardness of the distal portion of the involved artery. Therefore, surgery was concluded with STA-MCA anastomosis and only proximal internal carotid clipping. The postoperative angiography demonstrated well functional anastomosis and obliteration of dolichoectasia. She discharged on improvement of her condition on the 23rd day after operation. CT scan performed 6 months after operations showed the mass lesion to have become definitely reduced in size. The application of bypass surgery to the internal carotid dolichoectasia was reported with review of the literatures.

[A case of aspergillotic meningoencephalitis associated with trigeminal neuralgia].

A case of aspergillotic meningoencephalitis associated with trigeminal neuralgia was reported. The patient, a 41-year-old female, was admitted to our hospital on Nov. 20, 1977 with the chief complaint of right trigeminal neuralgia. On admission right facial paresthesia and right abducens palsy were found. The skull x-ray and tomogram showed enlargement of the right superior orbital fissure. Ct scan revealed an irregular high density around the right superior orbital fissure. The examination of spinal fluid showed 75 mg/dl protein, 72 mg/dl sugar and 11 cells. A biopsy of the mass and trigeminal rhizotomy were performed on Dec. 21, 1977. Microscopically, the specimen was composed of nonspecific granulomatous inflammatory tissue. Thereafter, loss of visual acuity, total ophthalmoplegia and facial paresis gradually appeared on the right side with high fever elevation. Immunologically, peripheral blood lymphocytes responded normally to PHA and PWM, but numbers of lymphocytes showed a tendancy of decrease with deterioration. On the other hand, serum IgG and IgM levels were rather increased. CT scan showed that an irregular high density mass extended to the right orbital apex and the pterygoid fossa. Spinal fluid revealed 260 mmH2O pressure with 76 mg/dl protein, 55 mg/dl sugar and 293 cells, but no organisms were demonstrated. Four months after the operation, swelling of the right subtemporal region became remarkable, in which region a puncture revealed much pus retention, and Aspergillus fumigatus was cultured from the aspirated pus. The patient became comatose and died on May 20, 1978. Autopsy showed thick, yellowish green pseudomembranes covering from the right temporal tip to the basal cistern. The both of cerebral hemispheres were swollen and revealed multiple small softenings all over the brain. Small hemorrhage occupying the right temporal subcortex and microabscess located in the left thalamus were also seen. Microscopical examination disclosed that the pseudomembrane was composed of the necrotizing suppurative inflammation with branched septate hypha of Aspergillus. There have been a few reports of aspergillotic meningoencephalitis associated with trigeminal neuralgia and enlargement of the superior orbital fissure like this case. Some discussion was made on the importance for the diagnosis of aspergillosis to perform fungal culture and histological examination of materials obtained from the inflammatory site, and immunological data of this case was also presented.