Diffusion tensor imaging in chronic subdural hematoma: correlation between clinical signs and fractional anisotropy in the pyramidal tract.

BACKGROUND AND PURPOSE: Diffusion tensor imaging (DTI) was introduced as a good technique to evaluate structural abnormalities in the white matter. In this study, we used DTI to examine anisotropic changes of the pyramidal tracts displaced by chronic subdural hematoma (CSDH). MATERIALS AND METHODS: Twenty-six patients with unilateral CSDH underwent DTI before and after surgery. We measured fractional anisotropy (FA) values in pyramidal tracts of bilateral cerebral peduncles and calculated the ratio of the FA value on the lesion side to that on the contralateral side (FA ratio) and compared the ratios with motor weakness. Moreover, the relationships between FA ratios and clinical factors such as age, sex, midline shift, interval from trauma, and hematoma attenuation on CT were evaluated. RESULTS: FA values of pyramidal tracts on the lesion side were significantly lower than those on the contralateral side (0.66 +/- 0.07 versus 0.74 +/- 0.05, P < .0001). The FA ratio was correlated to the severity of motor weakness (r(2) = 0.32, P = .002). FA ratios after surgery improved significantly compared with those before surgery (0.96 +/- 0.08 versus 0.89 +/- 0.07, P = .0004). Intervals from trauma and the midline shift were significantly associated with decreased FA ratios (P = .0008 and P = .037). CONCLUSIONS: In patients with CSDH, a reversible decrease of FA in the affected pyramidal tract on DTI was correlated to motor weakness. These anisotropic changes were considered to be caused by a reversible distortion of neuron fibers and vasogenic edema due to the hematoma.

Supramolecular gels formed by amphiphilic low-molecular-weight gelators of N alpha,N epsilon-diacyl-L-lysine derivatives.

Simple L-lysine derivatives, N(alpha)-hexanoyl-N(epsilon)-lauroyl-L-lysine (1), its alkali metal salts (2-4), and two-component compounds that consist of 1 with 2 to 4, were synthesized and their hydrogelation and organogelation properties were studied. Addition of hydrochloric acid to an aqueous solution of the alkali metal salt at room temperature produced a translucent hydrogel. This hydrogelation occurred as a result of a change in nanostructure from micelle-like aggregates to nanofibers, which was induced by partial protonation of the carboxylate to form a carboxylic acid. On the other hand, two-component low-molecular-weight gelators exhibited amphiphilic gelation behavior and functioned as not only hydrogelators, but also as organogelators. FTIR studies revealed that lateral ionic interactions between the carboxylate, alkali metal cation, carboxylic acid, and protons, in addition to hydrogen-bonding and van der Waals interactions play a very important role in hydrogelation. Furthermore, it was found that the water-insoluble carboxylic acid compound underwent a precipitation-dissolution transition with a thermally reversible sol-gel transition in the two-component gelator systems.

Elongation of the pi-system of phthalocyanines by introduction of thienyl substituents at the peripheral beta positions. Synthesis and characterization.

1,4,8,11,15,18,22,25-octabutoxyphthalocyanines ((OBu)8Pcs) having eight 2-thienyl (1) and [2,2'-bithiophene]-5-yl (2) groups at beta positions and their zinc(II) and cobalt(II) derivatives were prepared from 2-thienyl- (3) or [2,2'-bithiophene]-5-yl (4)-substituted phthalonitriles in moderate to good yields. The electronic absorption spectra of the Pcs showed red-shifted Q-bands relative to beta-unsubstituted (OBu)8Pcs. The longer substituent, the [2,2'-bithiophene]-5-yl group, is more effective than the 2-thienyl group in enlarging the pi-conjugated system of the Pcs. The ring oxidation potential obtained by cyclic voltammetry shifted cathodically with increasing chain length, indicating destabilization of the HOMOs. Due to the shift of the Q-band, 2-thienyl- and [2,2'-bithiophene]-5-yl-substituted Pcs exhibit a remarkable color change from the original green color.

Acoustic neuroma with malignant transformation. Case report.

The authors describe the case of a 57-year-old woman who had a right-sided hearing disturbance that had remained untreated for 1 year. The diagnosis was of a right cerebellopontine angle tumor, and the patient underwent its removal via retrosigmoid approach. Pathologically, the tumor was a typical benign neuroma. Growth of residual tumor was detected 4 years after the initial operation, and it was treated with gamma knife surgery (GKS). Six months later, the tumor had grown, and the patient underwent surgery via a combined retrosigmoid-translabyrinthine approach. Abnormal mitotic figures were observed on histological studies, indicating that the tumor had become malignant. Thereafter, the tumor grew rapidly, and the patient died 6.5 years after the initial treatment. It cannot be ruled out that GKS affected the outcome, but the causal sequence was unclear. Because such a patient is rare, documentation of the case was considered clinically important.

Synthesis of multicomponent systems composed of one phthalocyanine and four terpyridine ligands.

Two phthalocyanine-based multiple ligands were synthesized and characterized. Photochemical and electrochemical properties were measured for zinc(II) phthalocyanines covalently linked with four ruthenium(II) bisterpyridyl complexes. The absorption and electrochemical results are indicative of electronic interaction between two photoactive and redox-active components. Fluorescence spectroscopy of the five nuclear complexes provides evidence of an efficient photoinduced intramolecular energy transfer between the ruthenium-based metal-to-ligand charge-transfer (MLCT) chromophores and the zinc(II) phthalocyanine core. The absorption and fluorescence spectra of the phthalocyanine-based multiple ligands change dramatically as a result of the coordination of metal ions with peripheral terpyridine ligands. This change of fluorescence intensity upon addition of metal ions can apply to an output signal for metal ion sensing. The direct attachment of metal ion receptors with a zinc phthalocyanine core enhanced efficiency of the energy- and electron-transfer reaction from the core to the metal complexes.

Construction of regulated nanospace around a porphyrin core.

A series of 1,3,5-phenylene-based rigid dendritic porphyrins were synthesized by Suzuki coupling between a porphyrin core and dendron units. The intramolecular energy transfer was studied by absorption and fluorescence spectroscopies. The encapsulation of the porphyrin core within the 1,3,5-phenylene dendron units was found to provide highly efficient energy transfer from the dendron units to the porphyrin core. The dendritic wedge structure affected the energy transfer efficiency. The 1,3,5-phenylene-based rigid dendron units act as highly efficient light-harvesting antennae. These dendritic porphyrins have also been examined as C(60) hosts and substrate-selective oxidation catalysts. The attachment of the second generation of 1,3,5-phenylene-based dendron units with the porphyrin core enabled a stable inclusion of C(60) in toluene. Furthermore, the size and shape of the nanospace in the rigid dendritic porphyrins were found to affect the selectivity of substrates in the catalytic olefin oxidations.

Supramolecular assemblies formed by new L-lysine derivatives of viologens.

L-Lysine derivatives of viologens form supramolecular assemblies of fibers and ribbons in some aromatic solvents, and the charge separation reaction in these self-assembling systems proceeds with a similar efficiency to the MV2+ system.

Low Molecular Weight Gelators for Organic Fluids: Gelation Using a Family of Cyclo(dipeptide)s.

Simple cyclo(dipeptide)s consisting of diverse amino acids are able to cause physical gelation in a wide variety of organic fluids, including edible oils, glyceryl esters, alcohols, and aromatic molecules. Minimum gel concentrations, FTIR spectroscopy, NMR spectroscopy, and electron micrograph are used to characterize gel phenomenon. The intermolecular hydrogen bonding between N-H and C=O in cyclo(dipeptide)s plays an important role in gelation. FTIR and X-ray diffraction data suggest that the aggregate responsible for gel is an assembly of hydrogen-bonded molecular ladders, which are initially formed from numerous molecules through intermolecular hydrogen bonding. The ladder-like aggregates are intertwined and interlocked, and finally immobilize organic fluids. The gelation ability is discussed in connection with the three-component solubility parameters of solvents. Copyright 2000 Academic Press.

Endovascular treatment for a ruptured persistent trigeminal artery variant aneurysm on the distal portion--case report.

A 71-year-old female presented with a rare case of ruptured aneurysm on the distal persistent trigeminal artery (PTA) variant trunk. The endovascular approach was used to successfully occlude the proximal PTA variant, as direct catheter approach to the PTA variant aneurysm on the distal portion was prevented by the tortuous course of the vessel. She was discharged without neurological deficit.

[Cranio-cervical junction dural arteriovenous malformation presenting with subarachnoid hemorrhage: report of two cases].

Most spinal dural arteriovenous malformations (AVMs) affect the thoracic and lumbar regions. The clinical features of dural AVMs are, usually, gradually progressing myelopathy, while hemorrhage is a rare occurrence. We have recently encountered two cases of cranio-cervical junction dural AVM which caused subarachnoid hemorrhage. Both patients, a 61-year-old and a 37-year-old man were admitted to our hospital due to sudden onset of severe headache. Left vertebral angiography demonstrated a dural AVM at the cranio-cervical junction. A left suboccipital craniotomy and left hemilaminectomy of the atlas were performed. Dural opening disclosed tortuous dilated abnormal vessels. The dural AVM was fed by multiple small dural branches of the left vertebral artery and drained into an intracranial pial vein. The dura where the left vertebral artery penetrated was coagulated and divided from the left vertebral artery. Postoperative courses of these patients were uneventful. The pathophysiology and surgical treatment of dural AVMs in the cranio-cervical junction are discussed.

Organogels Formed by N-Benzyloxycarbonyl-l-alanine 4-Hexadecanoyl-2-nitrophenyl Ester and Related Compounds

Organogels of low molecular weight compounds, N-benzyloxycarbonyl-l-alanine 4-hexadecanoyl-2-nitrophenyl ester (BLAHN) and related compounds, in methanol and cyclohexane solvents were studied by FT-IR, circular dichroism (CD), transmission electron microscope (TEM), and scanning electron microscope (SEM). The gels exhibited a thermally reversible sol-to-gel phase transition, which gave the thermodynamic parameters for the transition. The FT-IR spectroscopic results suggested that the intermolecular hydrogen bonding between N-H and C=O of urethane bond played a vital role in gelation. The aggregates for gelation were mainly assembled by pi-pi interaction, dipole-dipole interaction, and the hydrophobic interaction as well as hydrogen bonding for BLAHN. The comparison of CD spectra of BLAHN, N-benzyloxycarbonyl-d-alanine 4-hexadecanoyl-2-nitrophenyl ester (BDAHN), and related molecules indicated that the self-aggregation of gelator molecules gradually proceeds and the component molecules are cooperatively organized to form a chiral aggregate. The three-dimensional interlocking structures and tree-branched structures responsible for the immobilization of fluid were observed by TEM and SEM. Copyright 1997 Academic Press. Copyright 1997Academic Press

Neuroprotective effect of 4'-(4-methylphenyl)-2,2':6',2-terpyridine trihydrochloride, a novel inducer of nerve growth factor.

We have identified 4'-(4-methylphenyl)-2,2':6',2-terpyridine: trihydrochloride (SS701), which belongs to a family of a small unique neuroprotective agents. SS701 accelerated the production of nerve growth factor (NGF) in cultured astroglial cells, dose- and time-dependently. In in vivo studies, SS701, when administered 30 min after induced cerebral ischemia, neuroprotective effects on delayed neuronal death in Mongolian gerbils were evident. The neuroprotective effects of SS701 against ischemia-induced delayed neuronal death are attributed to stimulation of the production of NGF.

Intraoperative adjustable suture surgery for bilateral superior oblique palsy.

BACKGROUND: The modified Harada-Ito procedure has been reported to be an effective treatment for correction of cyclotorsion in bilateral superior oblique palsy. However, there are no reports regarding its use in intraoperative adjustable suture surgery. METHODS: The authors performed a retrospective study of 12 patients with traumatic bilateral superior oblique palsy who were classified as having either symmetric or asymmetric palsy according to the symmetry of the alternate hyperdeviation on side gazes. Cyclotorsion and vertical and horizontal deviation in the nine diagnostic positions were measured preoperatively and postoperatively. RESULTS: Of the 12 patients, 6 were determined to have symmetric palsy and 6 asymmetric palsy. Intraoperative adjustable suture surgery with the modified Harada-Ito procedure was performed bilaterally in the six patients with symmetric palsy and unilaterally in those with asymmetric palsy. The median measured value of extorsion in the primary position was reduced from 14.5 degrees to 2.5 degrees in patients with symmetric palsy and from 9.5 degrees to 2.0 degrees in those with asymmetric palsy. In downgaze, some degree of residual extorsion remained, and there was no significant change in esodeviation after surgery. In five patients with symmetric palsy and in all of those with asymmetric palsy, normal single binocular vision in the primary position but did not that in downgaze was restored after surgery. CONCLUSION: Intraoperative adjustable suture surgery is an effective treatment in correcting torsion, but may not be as effective for esodeviation in downgaze.

Synthesis and evaluation of a miniature organic model of chymotrypsin.

An artificial chymotrypsin, with all the features of the real chymotrypsin, namely a binding site (from cyclodextrin) attached to a catalytic site containing an imidazolyl group, a carboxylate group and a hydroxyl group, has been synthesized. This artificial chymotrypsin has a molecular weight of only 1,365 while the real enzyme has a molecular weight of 24,800. However, from preliminary measurements, both the real and artificial enzymes have approximately the same catalytic activity (both rate and binding constants).

High-level of cyclic AMP in the jujube plum.

A large amount of cyclic AMP-like substance was found in the imported commercial jujube plum, Zizyphi Fructus, commonly used in traditional Chinese Medicine. The fresh fruits of the jujube plum, as obtained from a local botanical garden, also contained comparable amounts of the substance. The substance was purified to an almost pure state from commercial material and was identified as cyclic AMP (adenosine-3',5'-monophosphate) by both chemical and biochemical means. Thus, it has been established that cyclic AMP content of the fruits of jujube plum reaches up to 500 nmoles/g dry weight; which is more than 10 times higher than the maximum value so far reported in other plants.