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Biomedical subjects

M Fujiki

Publications and source records attributed to M Fujiki.

At least 19 recordsLinked to original sources
PubMed2006

The relationship between paired pulse magnetic MEP and surgical prognosis in patients with intractable epilepsy.

PURPOSE: To assess whether paired pulse magnetic motor evoked potential (MEP) can predict surgical prognosis in patients with intractable epilepsy. METHODS: MEP of the unilateral hand muscles were recorded following paired pulse transcranial magnetic stimulation (TMS) of the motor cortex. The interstimulus intervals of paired stimulation were 1-16 ms with a conditioning stimulus that was 90% active motor threshold. Subjects were six patients with temporal lobe epilepsy (TLE) scheduled for anterior temporal lobectomy and three patients with myoclonic or head-drop seizures scheduled for anterior corpus callosotomy, resulting in the unilateralization of epileptic discharges. The hemisphere showing unilateral discharges was defined as the affected hemisphere. The intracortical inhibition and facilitation curve was drawn based on MEP before and after surgery and the relationship between MEP and surgical prognosis was investigated. RESULTS: In five patients with TLE showing class I surgical results (Engel's classification), the affected hemisphere showing cortical hyperexcitability preoperatively was almost normalized after surgery. However, in a patient with class III, the unaffected hemisphere showed cortical hyperexcitability before and after surgery. In the callosotomy group, two patients with excellent outcomes showed the same results as TLE group with class I. CONCLUSIONS: Paired pulse magnetic MEP may provide predictive value in terms of surgical outcome in those patients with intractable epilepsy.

Adolescent↗
PubMed2006

Urine cartilage oligomeric matrix protein (COMP) measurement is useful in discriminating the osteoarthritic Thoroughbreds.

OBJECTIVE: To quantify the urinary concentration of cartilage oligomeric matrix protein (COMP), and to evaluate the relationship between urinary COMP concentration and the catabolic activity of synovial fluid (SF) in diseased horses. METHODS: COMP in horse urine was detected by immunoblotting with a monoclonal antibody (mAb; 14G4) raised against equine COMP from articular cartilage. Urine and serum samples were obtained from 83 Thoroughbred horses with aseptic joint diseases (AJD, 79 horses) or septic joint diseases (SJD, four horses) at the time of anesthesia induction, and samples of SF were obtained during surgery. Control samples of urine (n=111) were collected from normal horses free of any orthopedic diseases after they had been racing. COMP concentration was determined in all samples using inhibition enzyme-linked immunosorbent assay (ELISA) with mAb 14G4. SF samples were also used for the quantification of gelatinase activity. RESULTS: Positive bands of COMP fragments were determined on the immunoblots with mAb 14G4. The urinary COMP concentrations in AJD and SJD horses (1.02+/-0.75 and 1.55+/-1.17 microg/100mg creatinine, respectively) were significantly higher than normal (0.57+/-0.29 microg/100mg creatinine). In 55 horses with fractures in the AJD group there was a logarithmic relationship (r=-0.45, P<0.001) between the urinary and SF COMP measurements, while the urinary COMP level was positively correlated with matrix metalloproteinase (MMP)-2 and -9 activities (r=0.30, P<0.05 and r=0.51, P<0.001, respectively) in SF. CONCLUSIONS: The urinary COMP assay with mAb 14G4 is useful for discriminating horses with osteoarthritis. The higher COMP levels in urine from such horses would be indicative of enhanced proteolytic activity, in addition to the increased COMP levels in the diseased joints.

Animals↗
PubMed2005

Total callosotomy for a case of lissencephaly presenting with West syndrome and generalized seizures.

CASE REPORT: An 11-month-old girl had an onset of oculogyric crisis at 2 months and she presented with epileptic spasms and generalized tonic seizures with series formation at 3 months. Her seizures were medically intractable and her development had gradually regressed after that. MRI showed severe lissencephaly in bilateral hemispheres. Interictal EEG showed hypsarrhythmia periodically and sporadic spike waves in the right hemisphere. The generalized tonic seizures began with bi-frontal polyspikes on EEG. Our diagnosis was lissencephaly presenting with West syndrome and generalized tonic seizures. A total callosotomy was performed at 11 months. OUTCOME: Postoperative frequency of seizures decreased prominently and developmental progression was resumed. CONCLUSIONS: This case showed that the corpus callosum may play an important role in some types of symptomatic West syndrome. Corpus callosotomy for treating symptomatic West syndrome should be considered as an option after careful selection and consideration of the timing of surgery.

Corpus Callosum↗
PubMed2005

Lateral supraorbital approach as an alternative to the classical pterional approach.

OBJECTIVE: The standard pterional approach has been used to approach aneurysms of the anterior circulation and the basilar tip, suprasellar tumors, cavernous lesions. The senior author (JH) established a lateral supraorbital approach as an alternative to the pterional approach after continuous trial and error. We describe the techniques of this approach based on clinical experiences. METHODS: The lateral supraorbital approach is more subfrontal and anterior than the pterional approach. This approach has been regularly used by the senior author (JH) in the last decade in more than 2000 operations for mostly aneurysms of anterior circulation, but also for tumors of the anterior fossa and parasellar area as well as the sphenoid wing area. RESULTS: This approach can be used to operate on most cases, in which the classical pterional approach would be used. There are almost no craniotomy-related complications with this approach. This approach is not suitable in certain lesions which need to be exposed from a more temporal perspective. CONCLUSION: This approach is simpler, faster, safer and less invasive than the classical pterional approach.

Humans↗
PubMed2005

Subtemporal approach to basilar bifurcation aneurysms: advanced technique and clinical experience.

OBJECTIVE: The surgical treatment of basilar bifurcation aneurysms is challenging, and many of these aneurysms are currently treated by endovascular means. However, the complete closure of the aneurysm by surgical clipping still remains the best and most permanent cure for the aneurysm. The "gold standard", subtemporal approach was established and introduced by Drake and it has been adapted by the senior author Hernesniemi. We describe our present modified technique of this approach based on clinical experience. METHODS: The subtemporal approach to basilar bifurcation aneurysms has been regularly used by the senior author Hernesniemi in recent 15 years in over 200 operations in Kuopio and Helsinki, Finland. RESULTS: This approach is suitable in most basilar bifurcation aneurysms except for those high above the posterior clinoid process. To avoid temporal lobe damage, cerebrospinal fluid drainage is necessary. Benefits of subtemporal approach are short operative and retraction times, and no need for skull base resection. CONCLUSION: The subtemporal approach is simple and safe in experienced hands, and should be considered the standard method to approach most basilar bifurcation aneurysms.

Basilar Artery↗
PubMed2005

Analysis of cartilage oligomeric matrix protein (COMP) degradation and synthesis in equine joint disease.

REASONS FOR PERFORMING STUDY: Cartilage oligomeric matrix protein (COMP) is abundant within cartilage; its turnover and/or degradation have been investigated in various equine joint diseases and it has been suggested that COMP fragmentation might be useful for monitoring such conditions. OBJECTIVES: To determine whether COMP metabolism is compromised in equine osteoarthritis (OA) and whether COMP degradation is a useful joint marker representing cartilage destruction. HYPOTHESIS: A monoclonal antibody (mAb) with a higher affinity for degraded COMP allows discrimination of diseased joints by quantifying COMP levels and fragmentation. METHODS: A mAb (clone14G4) was generated against equine cartilage COMP. The NH2-terminal sequence of enzyme-cut COMP fragments recognised by 14G4 was determined, as was the efficiency of binding to COMP (using a generated COMP peptide). COMP concentration and fragmentation were analysed in synovial fluid (SF) from normal horses and those with OA. RESULTS: The mAb 14G4 had a higher affinity for the smaller fragments of equine COMP, compared with a mAb (clone 12C4) generated against human COMP. The 14G4 epitope was identified as between C134 and F147. The COMP values in OA (mean +/- s.d. 205.8 +/- 90.9 microg/ml) were significantly higher than in the normal (133.1 +/- 31.5 microg/ml) SF. On the immunoblots of OA sample, the proportions of intact COMP were significantly lower, while smaller fragments ranging from 75 to 290 kDa were higher compared with the normal SF. CONCLUSIONS AND POTENTIAL RELEVANCE: The mAb 14G4 reliably detects COMP degradation as well as synthesis, and fragmentation analysis combined with quantification in SF could be useful to study equine OA.

Animals↗
PubMed2003

High frequency electrical stimulation attenuates progressive necrosis and cavitation following spinal cord injury.

This study evaluates the influence of preconditioning by following electrical stimulation on primary and secondary lesion formation following spinal cord injury in rats. The dorsal surface of the spinal cord was stimulated (500 Hz. 10 pulses/train, inter train interval of 10 sec. for 2 hrs) at the T7 level 24 hrs before a right side hemisection, carried out immediately after injury and maintained every 24 hrs for 7 days. Preconditioning by electrical stimulation of the spinal cord activates reactive astrocytes and significantly attenuates edema and progressive necrosis and cavitation, concerning especially the primary (1, 3 weeks post injury) and secondary (24 hrs, 1, 3 weeks post injury) lesion volume. The results suggest that pre-conditioning by electrical stimulation prevents spinal cord secondary lesion formation after injury, and that the beneficial effect is provided by astroglial cells with regard to their ability to attenuate trauma induced cellular cascades.

Animals↗
PubMed2003

Motor evoked potentials following transcranial magnetic stimulation after middle cerebral artery and/or basilar artery occlusions in rats.

To clarify the significance of motor evoked potentials following transcranial magnetic stimulation (MMEPs) in acute stage of cerebral ischemia, MMEPs were recorded in rats with the right middle cerebral artery (MCA) and/or the basilar (BA) artery occlusions. MMEPs from bilateral forelimb muscle and regional cerebral blood flow (rCBF) of the pons were recorded simultaneously. After MCA occlusion, the amplitudes of MMEPs from left forelimb were increased up to approximately 184-221% of the pre-ischemic value for 60 min, though the latencies were unchanged. On the other hand, in the rats of BA occlusion and both BA and MCA occlusion groups, MMEPs amplitudes were decreased to 8-25% of the pre-ischemic value for 60 min. Pontine rCBF was decreased to 28-44% in both groups. As a mechanism of the facilitation of MMEPs after MCA occlusion, the affection of the inhibitory mechanism between the cerebral cortex and the generator of MMEPs by MCA occlusion is speculated.

Animals↗
PubMed2003

Anxiety induced by repetitive transcranial magnetic stimulation is suppressed by chronic treatment of paroxetine in rats.

Repetitive transcranial magnetic stimulation (rTMS) has been shown to have a therapeutic effect on affective disorder and anxiety disorders. However, some reports have linked rTMS to a significant increase in anxiety in normal volunteers. This study investigates the effect of rTMS on anxiety and the use of acute and chronic paroxetine treatment on this animal model of anxiety. In normal rats, rTMS for 10 days induced anxiety, as shown by elevated plus maze, black and white box, and conditioned fear tests. This anxiety was suppressed by chronic, but not acute, paroxetine. These results suggest that rats receiving chronic rTMS treatment can be used as a model of anxiety and that the anxiety induced by rTMS might involve the serotonergic system.

Acute Disease↗
PubMed2002

Effects of inducible nitric oxide synthase and xanthine oxidase inhibitors on SEB-induced interstitial pneumonia in mice.

The authors have previously reported that intratracheal instillation of staphylococcal enterotoxin-B (SEB) induced interstitial pneumonia (IP) in autoimmune-prone mice. SEB-reactive T-cells were critically involved in the development of IP in this model. Concern has arisen about the hazards of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the process of lung injury and fibrosis. Therefore, the involvement of nitric oxide (NO) and superoxide anion (O2-) in the pathogenesis of IP in this autoimmune-prone model has been investigated. Nitrite/nitrate levels were increased in bronchoalveolar lavage (BAL) fluid and serum from SEB-injected mice. The signal of the NO-(N-(dithiocarboxy) sarcosine)2-Fe2+ complex was detected in the SEB-injected lung and whole blood by electron paramagnetic resonance (EPR) spectroscopy. NO production was significantly decreased by aminoguanidine (AG) treatment. Xanthine oxidase (XO) activity in the lung, BAL fluid, and plasma was increased with instillation of SEB, and 4-amino-6-hydroxypyrazolo(3,4-d)-pyrimidine (AHPP) significantly inhibited XO activity. Moreover, both AG and AHPP significantly decreased production of pro-inflammatory cytokines, numbers of infiltrated cells in BAL fluid, and the area of thickened alveolar septa in the SEB-injected lung. In conclusion, the overproduction of nitric oxide and super oxide anion were implicated in the pathogenesis of interstitial pneumonia, and inducible nitric oxide synthase and xanthine oxidase inhibitors had protective effects against interstitial pneumonia in this model.

Animals↗
PubMed2002

Serum level of cartilage oligomeric matrix protein (COMP) in equine osteoarthritis.

This study was designed to assay and compare cartilage oligomeric matrix protein (COMP) in horse sera, in samples from normal and joint diseased horses, and to investigate the relationships between COMP in sera and synovial fluids (SF) with keratan sulphate (KS) data. Sera from 38 horses free of any joint pathology (controls) and from horses with aseptic joint disease (AJD horses, n = 40) were assayed for COMP and KS concentrations. Of the 78 horses in the study, 53 were also assayed for COMP and KS concentrations in SF. COMP and KS were measured by inhibition ELISA, using monoclonal antibodies 12C4 and 5D4, respectively. The COMP concentration in sera from AJD horses (mean +/- s.d. 10.7 +/- 7.4 microg/ml) was significantly (P<0.02) lower than in control sera (14.8 +/- 7.8 microg/ml). The joint disease sera also had significantly lower (P<0.01) KS levels (180.5 +/- 61.8 ng/ml) than controls (237.1 +/- 116.1 ng/ml). A significant correlation (r = 0.52, n = 53, P<0.001) was seen between serum and SF in COMP levels; no such relationship was seen in KS levels. It is possible that serum COMP concentration could be a more specific marker of equine joint disease than any other described to date.

Animals↗
PubMed2001

Interplay of the main chain, chiral side chains, and solvent in conformational transitions: poly([(R)-3,7-dimethyloctyl]-[(S)-3-methylpentyl]silylene).

Light scattering, sedimentation equilibrium, viscosity, circular dichroism (CD), and UV absorption (UV) measurements were made on dilute solutions of poly([(R)-3,7-dimethyloctyl]-[(S)-3-methylpentyl]silylene)(PRS) as functions of molecular weight. From light scattering and viscosity data, PRS is found to be a very stiff polymer of persistence length q as large as 103 nm at 25 degrees C, essentially a 7(3) helix found in the solid state; q increases only gradually with lowering temperature between -15 and 25 degrees C. The CD data show that PRS undergoes a conformational transition around 3 degrees C in isooctane (transition temperature T(c)). The CD signal is largely positive at low temperatures, passes through zero at T(c), and becomes largely negative at higher temperatures; T(c) is independent of sample's chain length N. This is a highly cooperative helix (M)-to-helix (P) transition depending remarkably on N, as PRS is substantially rodlike. The CD data are converted to the fraction f(P) of P helix as a function of N and analyzed successfully by a statistical mechanical theory based on a helix reversal model, where a polymer chain consists of M and P helices intervened by helix reversals, with the result that the free energy difference DeltaG(h) between P and M shows a temperature dependence similar to that of 2f(P) - 1, whereas the helix reversal energy is substantially constant at 1.2 x 10(4) J mol(-1); the latter value means that the helix reversal occurs only once in 100 Si units or less. This DeltaG(h) change and solvent dependence of T(c) are explained by a double-well potential for the rotation about Si-Si bonds, which incorporates into DeltaG(h) the solvent interactions with the helical grooves of side chains surrounding the main chain. Detailed features of UV absorption spectra at different temperature and molecular weights are also presented.

Journal Article↗
PubMed2001

Computing handedness: quantized and superposed switch and dynamic memory of helical polysilylene.

Two new conjugating helical polymers comprising a rodlike silicon backbone and enantiopure chiral pendants, poly[(R)-3,7-dimethyloctyl-(S)-3-methylpentylsilylene] (PS-1) and its diastereomeric poly[(S)-3,7-dimethyloctyl-(S)-3-methylpentylsilylene] (PS-2), were prepared. Molecular mechanics calculations of PS-1 and PS-2 model oligomers indicated a double well potential energy curve corresponding to almost enantiomeric helices with dihedral angles of 150-160 degrees (P-motif, global minimum) and 200-210 degrees (M-motif), regardless of their tacticity. Experimentally, it was found that PS-1 in dilute isooctane revealed switchable ambidextrous helicity on application of a thermal energy bias. Although PS-1 featured three distinct switching regions, viz. "region 1, between -80 and -10 degrees C", "region 2, between -10 and +10 degrees C", and "region 3, between +10 degrees C and +80 degrees C", the switching properties were interpreted as the result of superposed P- and M-helicities, undergoing dynamic pseudo-racemization or oscillation. Oscillating helicity in region 2 was roughly estimated to be about 13 cm(-)(1). The superposed helicity in region 2 was critical since it afforded molecular recognition ability with a dynamic memory function that was highly susceptible to solvent molecular topology and volume fraction. This could lead to potential as a molecular information processor to serve as a gauge of chemical properties. On the other hand, PS-2 could not switch its preferential screw-sense in the range of -80 to +80 degrees C. This may be related to greater differences the potential energy curve between P- and M-motifs.

Journal Article↗
PubMed2001

Solvent and temperature effects on the chiral aggregation of poly(alkylarylsilane)s bearing remote chiral groups.

Novel switchable chiroptical characteristics of poly(alkylarylsilane) microaggregates, controllable by the choice of good/poor solvent ratio (solvent polarity), solvent addition order, and sample temperature are described. The formation of stable chiral aggregates depends critically on the polysilane structure and stereochemistry. Poly[n-hexyl-(p-(S)-2-methylbutoxyphenyl)silane] (1), optically inactive in molecularly dispersed THF solution due to the existence of dynamically equivalent amounts of right (P)- and left (M)-handed screw sense helical main chain domains, shows a marked bisignate CD signal due to the formation of chiral aggregates in good/poor cosolvent systems. The sign and magnitude of the CD signals are dependent on solvent polarity, solvent addition order, and thermal effects. The less sterically hindered poly[methyl-(p-(S)-2-methylbutoxyphenyl)silane] (2) exhibits a weak, bisignate, nonswitchable CD signal in only the toluene/acetonitrile system, and no CD signals are evident in pure toluene or THF due to masking of the helicity. In contrast, although the even less sterically hindered, less polar poly[methyl-(m-(S)-2-methylbutoxyphenyl)silane] (3) does show optical activity in pure THF or toluene (negative CD signal at 310 nm), the CD signal disappears on formation of aggregates in good/poor cosolvent systems.

Journal Article↗
PubMed2001

Retro-odontoid soft tissue mass associated with atlantoaxial subluxation in an elderly patient: a case report.

BACKGROUND: We present the case of an elderly patient with a retro-odontoid soft tissue mass associated with atlanto-axial subluxation. CASE DESCRIPTION: A 74-year-old man was admitted to our hospital with progressive motor weakness in his right arm and neck pain. Radiological examinations revealed atlantoaxial subluxation and diffuse degenerative changes. Cervical MRI revealed a syrinx at the C1 level and a retro-odontoid soft tissue mass that severely compressed the spinal cord. The mass was of low signal intensity on both T1- and T2-weighted images. Conservative therapy could not stop the progression of his symptoms, so posterior decompression via a laminectomy of C1 and occipitocervical fixation was performed. These procedures resulted in an improvement of his neurological condition and in reduction of the mass and the compression of the spinal cord. CONCLUSION: The patient lacked any specific conditions that might have caused chronic atlantoaxial subluxation. The degenerative changes alone might have provoked chronic atlantoaxial subluxation and a subsequent retro-odontoid soft tissue mass. In patients with this condition, posterior fixation without direct removal of the mass should be the first choice for surgical intervention.

Aged↗