Rotational occlusion of the vertebral artery at the atlantoaxial joint: is it truly physiological?

We present a patient with vertebrobasilar insufficiency, with vertigo and horizontal nystagmus, induced by turning the head to the right. Angiography demonstrated transient occlusion of the left vertebral artery at the atlantoaxial joint during rotation of the head. The pathogenesis and angiographic findings are discussed.     

Regulation of phospholipase A2 in human leukemia cell lines: its implication for intracellular signaling.

Permeabilized human leukemia HL-60 and U-937 cells suspended in an acidic or alkaline medium release various unsaturated fatty acids, most abundantly oleic and arachidonic acids. Concomitant production of lysophospholipids suggests that phospholipases A2 play a major role in this fatty acid release reaction. The fatty acid release at acidic conditions depends on the intracellular Ca2+ concentrations at the 10(-8)-10(-7) M range and is enhanced by membrane-permeant diacylglycerols, although this enhancement seems independent of protein kinase C activation. On the other hand, the fatty acid release at alkaline conditions is potentiated by vanadate, and this potentiation is counteracted by genistein, suggesting a role of tyrosine phosphorylation in this release reaction. GTP[gamma S], an activator of G proteins, greatly enhances the fatty acid release. Aluminum fluoride, another activator of heterotrimeric G proteins, also greatly potentiates this release reaction. Phorbol ester increases the fatty acid release at alkaline conditions, to some extent, whereas it counteracts the vanadate-induced potentiation of fatty acid release. The results imply that several phospholipases A2 are coupled to receptors for their activation, thereby functioning in the transmembrane control of cellular events.     

Fatal necrotic enteritis associated with Clostridium perfringens in wild crows (Corvus macrorhynchos)

Sporadic outbreaks of fatal enteritis occurred among free-living wild crows (‘large billed’ or ‘wok’ crow; Corvus macrorhynchos) in an open-air park in Japan in 2002. Eight crows were found dead during February, followed by two more in September, and five of the eight were examined histopathologically. At necropsy, all cases showed a markedly dilated small intestine, especially the jejunum and ileum, with large amounts of gas, and dark red to greenish–brown soft content. The necrotic intestinal wall was markedly thickened with multifocal haemorrhages. All cases had multifocal white foci in the liver, and four cases showed marked splenomegaly. Histologically, there was severe necrotic enteritis characterized by extensive mucosal necrosis and multifocal haemorrhages, as well as inflammatory cell infiltrations. A prominent pseudo-membrane formation was noted in the affected intestine. Severe adhesive peritonitis was also observed in three cases. Gram-positive bacilli were present in large numbers in the lumen, and in and around necrotic lesions in the affected intestine. The bacilli were positive for Clostridium perfringens enterotoxin type A by immunohistochemistry, and were also positive for C. perfringens type A using the immunofluorescence method. C. perfringens was isolated by anaerobic culture from the intestinal contents. The present enteritis was thought to be induced by proliferated C. perfringens in the intestine, and to be the cause of death.     

Diffusion coefficient of water through dental composite resin

Water sorption of polymer filling materials affects dimensional stability, mechanical properties and bonding strength with tooth structures. To clarify the effect of the degradation on service life and micro-leakage, the diffusion coefficient of water through the resin should be identified. Distributions of time-dependent water concentrations in the resin were computed. Water sorption of composite resin discs with different thicknesses was measured and compared with the solution of Fick's second law. The diffusion coefficient of water through the resin discs was computed to be D=3.9-5.0 x 10(-13)m(2)/s from the measurements of specimens with different thicknesses. Results of water sorption measurements for the discs with different thicknesses were in good agreement with the theoretical results. The relationship among the thickness of the disc, the diffusion coefficient and the water sorption ratio was shown clearly. The testing method for water sorption by International Standard ISO 4049 for resin-based filling materials was discussed.     

Porous Ti-6Al-4V alloy fabricated by spark plasma sintering for biomimetic surface modification

Porous compacts with both biological and biomechanical compatibilities and high strength were developed. Spherical powders of Ti-6Al-4V alloy, which were either as received or surface modified with the use of calcium ions by hydrothermal treatment (HTT), were fabricated by a spark plasma sintering process. The porous compacts of pure Ti were used as reference materials. Porosity was approximately 30%, and compressive strengths were 113 and 125 MPa for the as-received Ti alloy powders and those modified by the HTT process, respectively. The bending strength and elastic modulus of as-received Ti alloy powders were 128-178 MPa and 16-18 GPa, respectively. Each of the compacts was immersed in simulated body fluid (SBF). The amount of adsorption/precipitation of calcium phosphate through the compacts was measured by weight change and was observed by SEM. The compacts were covered with calcium phosphate after 2 weeks of immersion in SBF. The compacts of Ti alloy had plenty of precipitated apatite crystals, and modification by HTT accumulated more precipitation. Because calcium phosphate is a mineral component of bone, apatite, which is precipitated on the surface of the compacts, could adsorb proteins and/or drugs such as antibiotics. It is expected that a large amount of proteins and/or drugs could be impregnated when the porous compacts developed are used.     

Correlation between microstructure of Ag-Pd-Au-Cu alloy and changes in shape on aging

An investigation has been carried out to study changes in shape on aging in plastic deformed Ag-Pd-Au-Cu alloys. The changes in shape were measured in order to establish a relationship to the aging heat treatments. Their microstructure was observed in order to clarify this phenomenon at the same time. They were also investigated quantitatively using a feature analysis system. The changes in shape were interpreted as the shrinkage in volume resulting from the formation of the ordered phase. They were smaller at aging temperatures below 673 K. The change in microstructure was different at aging temperature between 573 and 773 K. These phenomena were due to the following: First, nodules which nucleated at the grain boundaries would have grown into the grains well before the formation of the ordered phase, and second, the shrinkage in volume would have been of a different kind that the ordered phase. Therefore aging treatments should be carried out at low temperature in order to minimize the changes in shape. Also, nodular growth should be inhibited in order to maximize the hardening in Ag-rich alloys.     

A study on the effect of (2"R)-4'-O-tetrahydropyranyladriamycin, a new antitumor antibiotic, on reproduction. I. Its effect on the fertility of rats

The effect of a new antitumor antibiotic on the fertility was studied using SD rats. (2"R)-4'-O-Tetrahydropyranyladriamycin (THP) was administered to each rat at 0.01, 0.03 or 0.1 mg/kg daily. Males were given the drug intravenously for 63 days prior to mating and during the mating period; females were given the drug intravenously from 14 days prior to mating until day 7 of pregnancy. All the pregnant rats were sacrificed on day 20 of pregnancy, followed by external, visceral and skeletal observations of their fetuses. Results were summarized as follows. THP, at 0.1 mg/kg, suppressed body weight gain in females during the late period of pregnancy but did not affect body weight gain in males. THP, at 0.1 mg/kg, increased the numbers of dead fetuses and of resorptions. It caused no external, visceral or skeletal anomalies at any dose levels. The results suggest that, in rats, the maximum "no effect" dose of THP is 0.03 mg/kg/day intravenously regarding fertility and fetal development.     

A case of eosinophilic fasciitis without skin manifestations: a case report in a patient with lupus and literature review

Clinical Rheumatology - Eosinophilic fasciitis (EF) is a rare connective tissue disease that causes inflammation and fibrosis of the fascia, inducing pain and motor dysfunction. Characteristic skin...     

Case of multiple intrapulmonary lymph nodes]

A 45-year-old man who had hypertension, hyperthyroidism, and bronchial asthma was admitted to our hospital because of a low-grade fever and chest pain. The physical findings and laboratory data were almost all within normal limits except for evidence of mild inflammation and liver dysfunction. The chest X-ray findings seemed normal, but a computed tomography (CT) scan showed multiple nodules in both lower lung fields. We suspected the cryptococcosis or lung cancer. Biopsy by video-assisted thoracoscopic surgery (VATS) yielded a diagnosis of multiple intrapulmonary lymph nodes. In cases with the above radiologic findings, careful attention should be paid to making the differential diagnosis between intrapulmonary lymph nodes and primary lung cancer. The promotion of diagnostic imaging and advances in techniques have made it easier to identify small peripheral nodules in the lungs, and we now know of their existence. Solitary intrapulmonary lymph nodes are encountered frequently, but multiple or increasing numbers of nodes, as in our case, are very rare. Moreover, because cases with elevated CEA levels have been reported, differentiation from lung cancer appears to be important.