Proteins and protein-rich biomass as environmentally friendly adsorbents selective for precious metal ions.

Proteins exhibit specific interactions with various metal ions, which play important roles in a living cell. Here, we found that various proteins selectively adsorbed precious metal ions at a wide range of pH values. Studies on protein sequences and on synthesized peptides revealed that a histidine-containing sequence had specific interactions with precious metal ions (Au3+ and Pd2+). We then investigated a few types of protein-rich biomass as adsorbents for precious metal ions. In the presence of various transition metal ions, Au3+ and Pd2+ were also selectively adsorbed onto the biomass tested. The bound precious metal ions were recovered by aqua regia after charring the metal-bound biomass. Finally, we demonstrated the successful recovery of Au3+ and Pd2+ from a metal refining solution and a metal plating waste using the biomass. We propose an environmentally friendly recycling system for precious metal ions using protein-rich biomass.

Selective posterior rhizotomy for painful spasticity in the lower limbs of hemiplegic patients after stroke: report of two cases.

OBJECTIVE AND IMPORTANCE: Selective posterior rhizotomy (SPR) has been performed mainly in children with cerebral palsy. Seldom has the use of SPR been reported for reduction of spasticity after stroke. We describe two elderly patients with hemiplegia who underwent unilateral SPR for pain caused by spasticity after stroke. CLINICAL PRESENTATION: The first patient was a 68-year-old woman who experienced spasticity and pain in her right leg during the chronic stage of a left cerebral infarction. The second patient was an 89-year-old man who had intolerable spastic pain in his left hemiplegic leg 3 months after a right cerebral infarction. INTERVENTION: Both patients underwent unilateral SPR on the spastic side to reduce the pain. After surgery, the patients' pain resolved. In the first patient, the ability to perform activities of daily living also improved. CONCLUSION: Antispastic medications are often sufficient for treatment of post-stroke spasticity. In selected cases, however, SPR can be beneficial for improving painful spasticity.

Experimental study of the pathogenesis of moyamoya disease: histological changes in the arterial wall caused by immunological reactions in monkeys.

Moyamoya disease is a progressive vascular disorder of unknown etiology. Theories of inflammatory and immunologic mechanisms have been proposed as the pathogeneses. We have designed a new method of administering N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) for experimental induction of moyamoya disease using an intravascular interventional technique combined with rod-shaped embolic materials made from lactic acid-glycolic acid copolymer. The embolic materials containing MDP were repeatedly injected into the right internal carotid artery of monkeys in the embolic group. Intravenous injections of MDP solution alone were performed in the intravenous group. Histological examination of the arteries demonstrated reduplication and lamination of the internal elastic laminae, which corresponded with findings of moyamoya disease in both groups. These histological changes occurred not only in the intracranial arteries on the embolization side, but also in the contralateral intracranial and even extracranial arteries. The changes were more prominent in the intravenous group than in the embolic group. We conclude that the systemic humoral factors induced by MDP in this study may be important in the pathogeneses of moyamoya disease. Our observations suggest that moyamoya disease is a systemic vascular disease and has an etiologic factor affecting both intracranial and extracranial arteries

Attempt to establish an experimental animal model of moyamoya disease using immuno-embolic material--histological changes of the arterial wall resulting from immunological reaction in cats.

In this study, we investigated the relationship between intimal thickening of the internal carotid artery (ICA) and immunological reaction, and between occlusion of the ICA and development of basal collateral vessels in moyamoya disease. Rod-shaped lactic acid-glycolic acid copolymer (LGA-50) and N-acetylmuramyl-L-alanyl-D-isoglutamine (muramyl dipeptide: MDP), and immuno-embolic material, were injected into cats unilaterally via the common carotid artery. Histological changes of duplication of the internal elastic lamina could be seen mainly in the terminal portion of the ICA in the animals injected with rod-shaped LGA-50 containing MDP. No angiographic changes were seen in any of the animals. These findings suggest that the immunological reaction induced by MDP caused histological changes in the intima of the ICA similar to those observed in moyamoya disease. This experimental study, however, could not clarify the development of the basal collateral vessels.