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This paper deals with a robust control problem for a ball and beam system with an uncertainty. At first, we clarify the effect of a measurement error in the beam rotational angle and its differential value. It is expressed as additional terms in the state and input matrix of the state equation, which is called as a structured uncertainty. For this system, a robust tracking controller and a robust state observer are applied. Both components are designed based on a robust control, which is called guaranteed cost control. This is a kind of cost minimization method for designing problem of a linear feedback system. The controller is obtained as the solution of the matrix algebraic Riccati like equation, which is referred to as stochastic algebraic Riccati equation. The nominal system performance is degraded due to the influence of the uncertainty, but it is able to design a system with robustness for disturbance. Next, we consider the design problem of a state observer to estimate all state variables form the output signal easy to measure, like rotation angle of the beam. For the design problem of the state observer, we consider dual problem of the original system. Consequently, our proposed system estimates the whole state vector, and using estimated state values, it controls the ball to the desired position. Both components have robustness for the uncertainty. Numerical result shows the validity of our proposed method. [ABSTRACT FROM AUTHOR]

Cyanide-bridged Fe-Co complex [Fe(Tp)(CN)]Co(bpe)⋅5HO ( 1⋅5HO; Tp = hydro-tris(pyrazolyl)borate; bpe = 1,2-bis(4-pyridyl)ethane) shows temperature- and light- induced metal-to-metal charge transfer (MMCT) involving spin state changes between magnetic $\mathrm{Fe}^{\mathrm{III}}_{\phantom{\mathrm{III}}\mathrm{LS}}\mbox{--}\mathrm{Co}^{\mathrm{II}}_{\phantom{\mathrm{II}}\mathrm{HS}}$ (HS = high spin, LS = low spin) state and nonmagnetic $\mathrm{Fe}^{\mathrm{II}}_{\phantom{\mathrm{II}}\mathrm{LS}}\mbox{--}\mathrm{Co}^{\mathrm{III}}_{\phantom{\mathrm{III}}\mathrm{LS}}$ state, while the dehydrated material 1 does not show any MMCT and holds $\mathrm{Fe}^{\mathrm{III}}_{\phantom{\mathrm{III}}\mathrm{LS}}\mbox{--}\mathrm{Co}^{\mathrm{II}}_{\phantom{\mathrm{II}}\mathrm{HS}}$ state. We have investigated the magnetic properties of each spin state in 1 and 1⋅5HO by means of magnetization and ESR measurement under pulsed high magnetic field. At low temperature below T, in both 1 and 1⋅5HO, the saturation magnetization in the induced ferromagnetic phase is well explained by S and g values derived from the magnetic susceptibility study. In the ESR of 1, we observed characteristic modes corresponding to a spin excitation in the induced ferromagnetic phase where its temperature dependence shows an evolution of spin correlation in the $\mathrm{Fe}^{\mathrm{III}}_{\phantom{\mathrm{III}}\mathrm{LS}}\mbox{--}\mathrm{Co}^{\mathrm{II}}_{\phantom{\mathrm{II}}\mathrm{HS}}$ state at low temperature. We further found that the similar ESR modes grow in the light-induced state of 1⋅5HO. The results strongly suggest that the light-induced magnetization in 1⋅5HO is driven by a light-induced MMCT, which involves transition of spin multiplicity from the nonmagnetic $\mathrm{Fe}^{\mathrm{II}}_{\phantom{\mathrm{II}}\mathrm{LS}}\mbox{--}\mathrm{Co}^{\mathrm{III}}_{\phantom{\mathrm{III}}\mathrm{LS}}$ to the magnetic $\mathrm{Fe}^{\mathrm{III}}_{\phantom{\mathrm{III}}\mathrm{LS}}\mbox{--}\mathrm{Co}^{\mathrm{II}}_{\phantom{\mathrm{\mathrm{II}}}\mathrm{HS}}$ pair. [ABSTRACT FROM AUTHOR]

Iron(III) spin-crossover complexes [Fe(pap)2]ClO4 .O ( 1), [Fe(pap)2O ( 1), [Fe(pap)2]BF4O ( 2), [Fe(pap). H2O ( 2), [Fe(pap)2]PF6 . CH3OH ( 3), [Fe(CH3O ( 4), [Fe2]ClO4 . H2O ( 4), [Fe0.5Al0.5(pap)2]ClO4 . CH3OH ( 5) and [Fe0.25Al0.75(pap)2] ClO4 . CH3OH ( 6)were prepared andthe spin transition behaviors of the complexes have been studied from magnetic susceptibility and Mössbauer spectroscopy measurements. The magnetic properties of light-induced metastable state are measured using Hg-Xe light source. T 1/2is temperature at which the populations of the high-spin and low-spin species are fifty-fifty. Metastable HS is produced by light irradiation at 5 K. T(LIESST) is the temperature at which the populations of the metastable high-spin species decrease to one half and cooperativity factor Cis defined as the parameter which presents the strength of cooperativity. The value of T(LIESST) decreases as T 1/2increases and the plots of T(LIESST) vs. Cshow linear correlation. The effect of cooperativity of the complexes on the relaxations in solid was confirmed for the iron(III) complexes. [ABSTRACT FROM AUTHOR]

A new type of biosensor was fabricated by coating gold nanoparticles onto a film with a three-dimensionally ordered macroporous (3DOM) structure. It was found that the localized surface plasmon resonance of the immobilized nanoparticles changes with the infiltration medium inside the voids of the 3DOM film and the surface-adsorbed compounds. Application of this type of film to the real-time detection of immunoreaction was demonstrated. It is anticipated that this kind of film will have applications in label-free biosensors. [ABSTRACT FROM AUTHOR]

The magnetic properties of the spin-crossover compound, [Fe(qsal)2]NCSe·2DMSO (N-(8-quinolyl)-salicyladimine) (1), have been measured. We have discovered that the compound 1 exhibits a wide "thermal hysteresis loop" of 115 K (T1/2↑ = 324 K and T1/2↓ = 209 K) in the first cycle. Thermogravimetric analysis shows that solvent molecules of the compound 1 are removed at around 324 K. This means that the hysteresis loop observed for the first cycle is only an apparent one. Following the first loop, the compound 1 shows a spin-crossover in warming mode. The spin transition occurs at T1/2↑= 285 K and T1/2↓ = 209 K and the hysteresis width can be estimated to be 76 K, which is one of the largest values reported so far for spin-crossover compounds. It is thought that the cooperativity produced in the compound mainly arises from the intermolecular π interactions between the quinoline and the phenyl rings. [ABSTRACT FROM AUTHOR]

Among a number of techniques for gene transfer in vivo, the direct injection of plasmid DNA into muscle is simple, inexpensive and safe. Although combining direct DNA injection with in vivo electroporation increases the efficiency of gene transfer into muscle, applications of this method have remained limited because of the relatively low expression level. To overcome this problem, we developed a plasmid vector that expresses a secretory protein as a fusion protein with the noncytolytic immunoglobulin Fc portion and used it for electroporation-mediated viral interleukin 10 (vIL-10) expression in vivo. The fusion cytokine vIL-10/mutFc was successfully expressed and the peak serum concentration of vIL-10 was almost 100-fold (195 ng/ml) higher than with a non-fusion vIL-10 expression plasmid. The expressed fusion cytokine suppressed the phytohemagglutinin-induced IFN-γ production by human peripheral blood mononuclear cells and decreased the mortality in a mouse viral myocarditis model as effectively as vIL-10 expression. These results demonstrate that the transfer of plasmid DNA expressing a noncytolytic Fc-fusion cytokine is useful to deliver enhanced levels of cytokine without altering general biological activities. This simple and efficient system should provide a new approach to gene therapy for human diseases and prove very useful for investigating the function of newly discovered secretory protein genes. [ABSTRACT FROM AUTHOR]

Since the introduction of ventriculo-atrial and/or ventriculo-peritoneal shunting for hydrocephalic patients, controversies have developed regarding the likelihood of epileptic seizures developing as a result of the shunting itself and/or its complications. On the other hand, hydrocephalus is not commonly recognized as a cause of seizures in general, although epilepsy is reported to be frequently associated with shunt-treated hydrocephalus, especially in children. Several authors have reported an increased risk of epileptic seizures after shunt placement, but the underlying mechanisms are still controversial. The insult to the brain at the time of ventricular catheter insertion, the presence of the shunt tube itself as a foreign body, the burr hole location, the number of shunt revisions after malfunction, associated infection, the etiology of hydrocephalus, and associated mental retardation are thought to be related to the risk of epilepsy. Age at the time of initial shunt placement also seems to be an important factor. Early shunting is a well-known determinant of risk in shunt obstruction, and children less than 2 years old are consequently at a higher risk of developing epilepsy than older ones. It is reported that antiepileptic drug treatment is not so reliable as might be expected. Conscientious and more sophisticated EEG recording in those children may be beneficial during follow-up. The incidence of seizures in shunted children is reported to be quite high, ranging from 20% to approximately 50%, so that neurosurgeons should pay more attention to the issue of epilepsy in hydrocephalic children. Although ventriculo- extracranial shunts have been the standard treatment for hydrocephalus for decades, the long-term morbidity, including postshunt epileptic seizures, has to be taken seriously. The use of neuroendoscopic techniques when indicated may ameliorate this problem a great deal in the future. [ABSTRACT FROM AUTHOR]

The electronic states of Fe atoms in Co[Fe(CN)5NH3 $$\cdot x $$ H2O were studied by means of 57Fe Mössbauer spectroscopy. The Mössbauer spectra of Co[Fe(CN)5NH3 $$\cdot $$ 6H2O show the coexistence of mixed valences for the Fe atoms and a magnetic relaxation at 4 K. When water molecules were removed, electron transfer from Co to Fe occurred. [ABSTRACT FROM AUTHOR]

Platelet-derived growth factor (PDGF), especially its B chain, has been implicated in the pathogenesis of vascular proliferative disorders such as atherosclerosis and restenosis after angioplasty. We constructed a replication-deficient recombinant adenovirus containing the gene encoding the extracellular region of PDGF β-receptor (PDGFXR) that binds PDGF-B chain and acts as its antagonist. The administration into balloon-injured rat carotid arteries of an adenovirus containing the Escherichia coli lacZ gene as a marker gene at 5 days after injury markedly facilitated efficacy of gene transfer, as compared with its administration immediately after injury. Adenovirus-mediated gene transfer of PDGFXR into injured arteries performed at 5 days resulted in a more than 50% reduction in the neointimal area of injured arteries at 14 days. In con- trast, the administration of control adenoviruses containing lacZ gene or containing no foreign gene was without suppressive effects on neointima formation. The inhibition of neointima formation by the expression of PDGFXR was accompanied by a reduction in bromodeoxyuridine-labeled cells and nearly complete inhibition of tyrosine phosphorylation of both α- and β-receptors for PDGF, but not of epidermal growth factor receptor, in injured arteries. This is the first report to indicate the usefulness of targeting a growth factor by expressing an extracellular binding region of a receptor using an adenovirus for the treatment of vascular proliferative disorders, and provide direct evidence that PDGF-B chain plays an essential role in neointimal formation. [ABSTRACT FROM AUTHOR]

We prospectively analysed treatment results in patients with severe subarachnoid haemorrhage (SAH) who underwent early aneurysm surgery, and were managed by dehydration therapy. We studied a total of 31 patients with poor-grade SAH including 18 in grade IV, and 13 in grade V according to the WFNS classification system. Patients who were older than 70 years of age, or those with an intracerebral haemorrhage or absent brainstem response were excluded from this study. At surgery, clot evacuation from the peribrainstem cisterns with/without external decompression was performed following obliteration of the aneurysmal neck. In the early postoperative period, patients were maintained in negative water balance using osmotic diuretics. When delayed ischaemic deficits had manifested themselves, the pulmonary wedge pressure and/or central venous pressure was immediately increased by the rapid injection of albumin until hypovolaemia reverted to normovolaemia with the continuous administration of dobutamine. The outcome at 3 months was good recovery in 16 (52%) patients, moderate disability in 3 (10%), severe disability in 5 (16%), a vegetative state in 1 (3%), and death in 6 (19%). We thought that early aneurysm surgery and postoperative dehydration therapy in the acute stages of brain oedema resulting from primary brain damage are effective in the treatment of patients with severe SAH but reversilbe primary brain damage. [ABSTRACT FROM AUTHOR]

Electrical stimulation of 8 μA direct current was applied to the femoral distal growth plate of young rabbits for periods of 1, 2, and 3 weeks to examine the effect on bone growth. The results were analyzed using X-ray measurement, histological observation including tetracycline labeling, and glycosaminoglycans analysis. No obvious differences between the stimulated side and the control side were observed in the morphological and biochemical studies, but characteristic thickening of the growth plate caused by the accumulation of hypertrophic cells was found in the group stimulated for 2 weeks. Electricity affects the cell behavior of the growth plate, but it is necessary to find more appropriate conditions to stimulate obvious bone growth. [ABSTRACT FROM AUTHOR]

The authors have developed a new method of magnification cerebral angioautotomography which is performed by the use of a special head-swing apparatus. From the results of experiences of 24 intracranial aneurysms in 15 patients, the method has proved useful for the intracranial aneurysms in detecting the shape and the stalk of aneurysms which were obscured or hidden on conventional magnification cerebral angiography. [ABSTRACT FROM AUTHOR]

A case with seven intracranial aneurysms is reported. Six aneurysms were on the left internal carotid artery and one on the right internal carotid artery. Magnification angioautotomography was used to demonstrate the aneurysms clearly. [ABSTRACT FROM AUTHOR]

Cerebral haemodynamics were measured in 22 adult patients with secondary normal pressure hydrocephalus (NPH) before and after glycerol administration to determine which patients might benefit from a shunt procedure. Of these 22 patients, 14 were found to be shunt-responsive (group 1) and 8 were shunt-unresponsive (group 2). Measurement of regional cerebral blood flow (rCBF) was performed by xenon-enhanced computerized tomography (XeCT). Clinical factors such as the Evans' index and the presence or absence of brain atrophy, periventricular lucency (PVL), ventricular reflux, stagnation of cerebrospinal fluid on cisternography, and increased intracranial pressure were not statistically significant predictors of shunt responsiveness. Preoperative rCBF values did not differ between groups 1 and 2. The rCBF value in every cerebral region of group 1 patients increased significantly after shunting except for the basal ganglia. On preoperative rCBF measurement, all rCBF values in group 1 significantly increased after glycerol administration except for the periventricular lucency (PVL). Patients in group 2, however, lacked such an increase in rCBF. We therefore propose that, in patients with secondary NPH, shunt surgery will be likely to be effective in those with a demonstrated rise in rCBF after glycerol administration. [ABSTRACT FROM AUTHOR]

Cisternal and/or ventricular cerebrospinal fluid (CSF) and arterial blood lactate and acid-base balance were measured serially in 38 patients with aneurysmal subarachnoid haemorrhage (SAH). Based on daily clinical assessment, the patients and accordingly the samples were divided into two groups according to the grading of the World Federation of Neurosurgical Societies (W.F.N.S.). In cisternal CSF, samples of Grade III-V showed significantly higher lactic acidosis than those of Grade I-II. The time course of lactate and pH in poor prognosis groups had a significant tendency of lactic acidosis, especially on the 5th, 6th, 7th day after SAH. Ventricular CSF lactate increased even without CSF acidosis in Groups III-V. Measurement of CSF lactate, especially from the cisterna magna is useful as an indicator of prognosis and changes of intracranial environment following SAH. [ABSTRACT FROM AUTHOR]

Measurement of plasma alpha-humanANP (ANP) and antidiuretic hormone (ADH) in 28 cases with aneurysmal subarachnoid haemorrhage (SAH) was carried out, and then compared with control subjects who were infused with hypertonic saline. In cases with hyponatremia (HN), statistical correlation between control subjects and cases without HN was not evident with regards to ANP and plasma osmolality (Posm), excreted fraction of filtrated sodium (FENa) and urinary Na/K. Furthermore, they secreted supernumerarilly in spite of HN. Cases with HN were further subdivided into two groups, they were those cases with negative total sodium balance at the time of appearance of HN, and those cases without total negative sodium balance. In the former, central venous pressure had a tendency to decrease, however, secretion of ANP and ADH was statistically not different in either groups. It appears that ANP regulated urinary sodium excretion against an osmotic or sodium load acts as a maintenance of homeostasis as an osmotic regulator. Cases with HN in which secretion of ADH was physiological, ANP secreted supernumerarilly in spite of hypoosmonaemia and hypovolaemia. Our findings may contribute to a better understanding of the pathophysiological processes leading to hyponatremia in cases with cerebral disorders, and may help to improve the treatment possibilities. [ABSTRACT FROM AUTHOR]

One case of a pontine haematoma with clinical symptoms of cerebellopontine angle tumour is described. The haematoma was successfully evacuated, and preoperative neurological deficits disappeared except for minimal right fifth nerve palsy. The pathological specimen was diagnosed as arteriovenous malformation. Lateropontine haematomas must be included in the differential diagnosis of cerebellopontine angle tumours. [ABSTRACT FROM AUTHOR]

Supratentorial approach through the cerebellar tentorium for removal of cerebellar haemangioblastomas located on the anterosuperior surface of the cerebellum is described. This approach with the aid of microsurgery is especially suitable for a haemangioblastoma involving the midbrain. [ABSTRACT FROM AUTHOR]

The P-glycoprotein (P-Gp) encoded by the human multidrug-resistance gene MDR1 has been suggested to play certain roles in the blood-brain barrier (BBB). However, the detailed mechanism of the activity of P-Gp in multidrug-resistance (MDR) remains unclear in human glioma. We examined the localization of P-Gp in human glioma by immunohistochemical (IHC) and immunoelectron microscopic (IEM) methods with anti P-Gp monoclonal antibodies (C219, MRK16). We also examined MDR1 expression in primary glioma and xenografts by reverse transcription-polymerase chain reaction (RT-PCR) with human MDR1-specific primers. The IHC study showed no P-Gp expression on tumour cells but it was present on capillary endothelial cells and IEM analysis showed definitive localization on their luminal surface. MDR1 gene expression was detected in eight primary glioma and three normal brain specimens by RT-PCR, but not in glioma xenografts. The lack of MDR1 expression in these cells appears to be a consequence of the replacement of the original human stroma, including blood vessels, by murine stroma in glioma xenografts. The unique distribution of P-Gp on the capillary blood vessels was confirmed in human glioma by the results of immunohistochemical and molecular biological studies. [ABSTRACT FROM AUTHOR]

Morphological and developmental changes of the ventricular system are analyzed in three major experimental models of congenital hydrocephalus in the rat: 6-aminonicotinamide (6-AN)-induced and LEW/Jms and HTX mutant hydrocephalus. The clinically comparable forms of hydrocephalus and problems occurring during each period of intrauterine hydrocephalus are then discussed. Comparative morphological study revealed that 6-AN-induced hydrocephalus was comparable to the Dandy-Walker syndrome and that the critical period regarding this syndrome in fetal life was at the time of 'legal termination'. The LEW/Jms and HTX mutant models were identical with regard to the form of progressive hydrocephalus in the postnatal period, but the condition underlying the hydrocephalus during the fetal period differed. The LEW/Jms model was comparable to primary congenital aqueductal stenosis (aqueductal agenesis), and the hydrocephalic state appeared in the period of 'intrauterine preservation' before pulmonary maturation was completed. On the other hand, the HTX fetuses demonstrated secondary change of the aqueduct in the perinatal period, although the model was considered to be of congenital communicating hydrocephalus. Cerebrospinal fluid (CSF) dynamics studied in the fetuses with 6-AN-induced hydrocephalus disclosed considerable pathophysiology comparable to 'hydromyelic hydrocephalus.' The historical trends of animal experimental models of congenital hydrocephalus are reviewed and comparable clinical problems suggested by those models discussed further. [ABSTRACT FROM AUTHOR]

Since hydrocephalus cannot be regarded as a single entity but is a group of illnesses whose pathophysiology remains unexplained in many aspects, its classification is particularly important. Various types of hydrocephalus are discussed with special reference to their etiology. The need for more research work is stressed. [ABSTRACT FROM AUTHOR]

Energy metabolism in kaolin-induced hydrocephalic rat brain was assessed by means of 31-phosphorus magnetic resonance spectroscopy and measurement of the activity of lactate dehydrogenase (LDH) as well as its isoenzyme patterns. Decreases in beta-adenosine triphosphate and phosphocreatine were observed in hydrocephalic rat brains. While the intracellular pH was decreased at 2 to 4 weeks, it showed some recovery 6 weeks after injection of kaolin. The activity of LDH increased in the hydrocephalic state, and its isoenzyme-pattern changes were as follows: the LDH5 fraction was predominant in 1-week to 4-week rats while the LDH4 fraction was predominant in 4-week rat brains, and at 6-weeks, the LDH4 and LDH5 fractions were decreased. These data from rat brains with kaolin-induced hydrocephalus indicate that anaerobic glycolysis is the primary pathway of energy metabolism in the acute hydrocephalic state, while in the chronic state the emphasis shifts to aerobic glycolysis. [ABSTRACT FROM AUTHOR]

A dipping method has been developed for the infiltration of nanoparticles into an opal template to fabricate high quality inverse opal. Titania and silica inverse opal films, with a uniform color over centimeter dimensions were derived. As there is no need for special substrates or equipment, a widespread application of this method is anticipated. [ABSTRACT FROM AUTHOR]

Using xenon-enhanced computed tomography for the study of cerebral blood flow, simultaneous measurements of end-tidal and arterial blood xenon concentrations using the blood collection method were performed to investigate the validity of substituting the end-tidal for the arterial blood xenon concentration. Simultaneous measurement by both methods was performed 68 times in 27 patients. There was no statistical correlation between the arterial blood accumulation rate constant obtained by arterial blood and end-tidal samples, nor between the arterial blood saturation value obtained by the two methods, even when correction was made for age. In brain tissue, all parameters calculated using the end-tidal concentration were lower than those using arterial blood. We therefore suggest that cerebral blood flow values calculated using end-tidal xenon concentration are useful only for qualitative cerebral blood flow mapping, and not applicable to absolute values of cerebral blood flow. [ABSTRACT FROM AUTHOR]

The angiographic investigation of intracranial aneurysms in geriatric patients was made by conventional cerebral angiography and angioautotomography. Analyses were based on 49 aneurysms in 38 patients aged over 60 who had 24 (49.0%) large aneurysms of maximum diameter over 100 mm. This contrasted strongly with the aneurysms of patients aged under 60, only 14.4% of which were large. Cerebral angioauto-tomography had a particular diagnostic value for such large aneurysms, revealing not only the stalks and the whole shapes of aneurysms, but also the normal parent arteries which were hidden on conventional cerebral angiography. [ABSTRACT FROM AUTHOR]