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  • 1
    Electronic Resource
    Electronic Resource
    Increased glycosylation of proteins from cataractous lenses in diabetes (1983)
    Springer
    Diabetologia 25 (1983), S. 36-38 
    Details
    ISSN: 1432-0428
    Keywords: Lens proteins ; human diabetic cataracts ; non-enzymatic glycosylation ; 5-hydroxymethylfurfural ; thiobarbituric acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The rates of glycosylation of lens proteins were determined in extracts of human ‘diabetic’ and ‘senile’ cataractous lenses by a method employing thiobarbituric acid. Incubation of soluble lens proteins (6,500×g supernatant of homogenates) in vitro with various concentrations of D-glucose in sodium phosphate buffer (50 mmol/l, pH 7.2) resulted in a gradual glycosylation which was time and concentration dependent. Glycosylated proteins from the cataractous lenses of 21 senile and 12 diabetic subjects afforded 0.72 ±0.22 and 1.84±0.44 nmol 5-hydroxymethylfurfural/mg protein (mean±SD), respectively. The value is significantly higher in the diabetic than in the senile group (p〈0.001), although the mean age of the diabetic patients (67 years) was significantly younger than that of senile subjects (75 years; p〈0.01). These results indicate that human lens proteins can be glycosylated both in vitro and in vivo, and that hyperglycaemia can accelerate the non-enzymatic glycosylation of lens proteins in diabetic patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00251894
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  • 2
    Electronic Resource
    Electronic Resource
    Symptomatic cerebral vasospasm of unusually late onset after aneurysm rupture (1991)
    Springer
    Acta neurochirurgica 108 (1991), S. 163-166 
    Details
    ISSN: 0942-0940
    Keywords: Symptomatic vasospasm ; delayed operation ; late onset
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An unusually late occurrence of symptomatic cerebral vasospasm is reported. The case involves a 50-year-old male who was uneventfully operated on for a ruptured anterior communicating artery aneurysm, with no symptom of cerebral vasospasm, 17 days after sustaining the subarachnoid haemorrhage. Two days after surgery, a right hemiparesis developed and angiography disclosed severe cerebral vasospasm. This case history and the aetiological factors of symptomatic vasospasm are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01418526
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  • 3
    Electronic Resource
    Electronic Resource
    Some osteocytes released from their lacunae are embedded again in the bone and not engulfed by osteoclasts during bone remodeling (2000)
    Springer
    Anatomy and embryology 202 (2000), S. 119-128 
    Details
    ISSN: 1432-0568
    Keywords: Key words Serial sections ; Cutting cones ; Closing cones ; Bone cells ; Cement lines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  It is generally accepted that osteocytes derive from osteoblasts that have secreted the bone around themselves. Osteocytes are cells embedded in the lacunae in the bone, and they are characteristically in contact with other cells by many slender cytoplasmic processes in canaliculi. During bone remodeling, many osteocytes in the bone are released from their lacunae by osteoclasts; however it remains unclear what happens to these released osteocytes. The cortical bone of the rat mandibular body was used in this study. Mandibles were fixed, decalcified, and then embedded in Epon 812. Specimens were sectioned in the frontal direction into serial 0.5 µm-thick semithin or 0.1 µm-thick ultrathin sections, and then examined by light or transmission electron microscopy. Cells that fitted in the osteocytic lacunae with canaliculi extending to the bone were identified as osteocytes in this study. Among many osteocytes released by osteoclasts in cutting cones, there were osteocytes half-released from their lacunae. These cells fitted in their lacunae with canaliculi extending to the bone and showed developed cell organelles in the cytoplasm. In closing cones, many osteocytes were situated in the bone away from cement lines; however, there were half-embedded osteocytes in the bone formed on cement lines. These cells fitted in their lacunae with canaliculi extending to the bone formed below cement lines and showed developed cell organelles in the cytoplasm. These results show that half-embedded osteocytes in closing cones derive from half-released osteocytes in cutting cones. Osteocytes encircled by osteo- clasts were sometimes observed on one section, but se-rial sections showed that these osteocytes fitted in their remaining lacunae in the bone on other sections. This shows that not all osteocytes released from their lacunae are engulfed by osteoclasts. Consequently, the present results suggests that some osteocytes released from their lacunae are embedded again in the bone and not engulfed by osteoclasts during bone remodeling.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290000101
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  • 4
    Electronic Resource
    Electronic Resource
    The effects of 5-minute ischemia in Mongolian gerbils: II. Changes of spontaneous neuronal activity in cerebral cortex and CA1 sector of hippocampus (1983)
    Springer
    Acta neuropathologica 60 (1983), S. 217-222 
    Details
    ISSN: 1432-0533
    Keywords: Neuronal activity ; Ischemia ; Hippocampus ; Gerbil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Spontaneous neuronal activity was recorded in the cerebral cortex and the CA1 sector of the hippocampus in gerbils during and after 5-min ischemia, produced by bilateral clamping of the common carotid arteries. It was found that spontaneous activity in both cortical and CA1 neurons ceased within 60 s after the onset of ischemia and that it began to reappear 10–20 min after the recirculation. During the next 24 h most CA1 neurons which were recorded showed hyperactivity. This was evident primarily by an increase in spike discharges, whereas recordings from the cerebral cortex were within the preocclusion ranges. On the 2nd day after ischemia, functioning CA1 neurons could not be found, as if they were in a state of functional death, although histological sections showed a general preservation of their cellular structure at that time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691869
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  • 5
    Electronic Resource
    Electronic Resource
    The effects of 5-minute ischemia in mongolian gerbils: I. Blood-brain barrier, cerebral blood flow, and local cerebral glucose utilization changes (1983)
    Springer
    Acta neuropathologica 60 (1983), S. 207-216 
    Details
    ISSN: 1432-0533
    Keywords: Cerebral ischemia ; Blood-brain barrier ; Cerebral blood flow ; Glucose utilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Changes in morphology, behavior of the blood-brain barrier (BBB), regional cerebral blood flow (rCBF), and local cerebral glucose utilization (LCGU) were assessed and correlated in Mongolian gerbils following 5 min cerebral ischemia, produced by bilateral clamping of the common carotid arteries. The morphological changes were confined to the hippocampus and revealed a conspicuously delayed destruction of the CA1 neurons, occurring after 3 days. Following release of carotid occlusions, there were two separate openings of the BBB. One, occurring shortly after recirculation, was associated with focal hyperemia in the cerebral cortex, hippocampus and basal ganglia; the second opening was observed after several days and was associated with severe neuronal destruction in the CA1 sector. Correlation of quantitative and qualitative rCBF assays with14C-deoxyglucose autoradiographic observations indicated an uncoupling between blood flow and glucose metabolism, observed in the hippocampus at 10 min after recirculation. The described changes provide a further insight into the post-ischemic events which determine the outcome of ischemic injury.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691868
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  • 6
    Electronic Resource
    Electronic Resource
    Ultrastructural observations on the transvascular route of protein removal in vasogenic brain edema (1985)
    Springer
    Acta neuropathologica 66 (1985), S. 265-273 
    Details
    ISSN: 1432-0533
    Keywords: Cold-lesion injury ; Brain edema ; Blood-brain barrier ; Alkaline phosphatase ; Anionic sites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Micro-blood vessels (MBVs), located in the area of edema, were studied in cat brain at various time intervals (1 h, 24 h, 7 days) after cold-lesion injury. Both cold-injured and adjacent gyri were examined for blood-brain barrier (BBB) permeability to i. v. injected horseradish peroxidase (HRP) with circulation times of 40 min and 24 h. Evans blue (EB) was used as a tracer for gross evaluation of the extension of brain edema. Localization of alkaline phosphatase (AP) and binding of cationized ferritin (CF), considered as a marker of anionic sites, were also studied ultrastructurally. Twenty-four hours after cold injury, the extravasated edema fluid, outlined by EB tracer, was observed to be spreading through the white matter (WM) into the adjacent gyrus. At this time, numerous, larger than capillary MBVs, presumably arterioles and venules located in the edematous WM, showed accumulations of HRP injected at the time of the operation, in the basement membrane, in abluminal pits, and in numerous pinocytotic vesicles and vacuoles of endothelial cells (ECs). The animals killed after 24 h with 40 min HRP circulation showed extravasation of HRP tracer in a zone underlying the necrotic cold injury lesion. On the other hand, there was no evidence of an abnormal HRP leakage in the further removed areas of edema in the WM, particularly in the adjacent gyrus. These observations suggest that a reverse, vesicular transport of HRP across the ECs of some MBVs represents one of several possible mechanisms responsible for the removal of extravasated proteins and of edematous fluid from brain extracellular space. This reverse transport is accompanied by a disruption of the surface anionic layer and changed polarity of ECs manifested by the relocation of AP activity from luminal to abluminal plasmalemma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690958
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  • 7
    Electronic Resource
    Electronic Resource
    Time course of activated coagulation time at various sites during continuous haemodiafiltration using nafamostat mesilate (1999)
    Springer
    Intensive care medicine 25 (1999), S. 524-527 
    Details
    ISSN: 1432-1238
    Keywords: Key words Nafamostat mesilate ; Continuous haemodiafiltration ; Activated coagulation time ; Anticoagulation ; Haemofilter ; Polymethylmethacrylate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: To determine the adequate site of activated coagulation time (ACT) measurement during continuous haemodiafiltration (CHDF) using nafamostat mesilate. Design: Prospective, consecutive, clinical study. Setting: An intensive care unit of a general hospital. Patients: Ten patients with acute organ failure including kidney, lung and liver, caused by sepsis after major surgery. Interventions: A CHDF circuit with a haemofilter made of polymethylmethacrylate membrane was primed with 50 mg nafamostat in 500 ml saline, and was started at a circuit flow rate of 100 ml/min. Continuous injection of 0.5 mg/kg per h nafamostat, 700 ml/h of dialysis fluid and 1000 ml/h of filtrate fluid was set. Measurements and results: The circuit pressure at the inlet and outlet of the circuit were monitored, and ACT was measured every 2 h at the site of nafamostat injection, outlet, patient's artery and inlet until 24 h. A value of standard deviation of ACT at each site was regarded as the variation value of ACT. The circuit pressure did not change significantly. The ACT did not change significantly at any measurement site. The variation value of ACT at the inlet of the circuit was significantly lower than that at the site of nafamostat injection. Conclusions: The ACT value at the inlet of the circuit may be adequate to monitor anticoagulation during CHDF using nafamostat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001340050892
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  • 8
    Electronic Resource
    Electronic Resource
    Trajectory formation of arm movement by cascade neural network model based on minimum torque-change criterion (1990)
    Springer
    Biological cybernetics 62 (1990), S. 275-288 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract We proposed that the trajectory followed by human subject arms tended to minimize the time integral of the square of the rate of change of torque (Uno et al. 1987). This minimum torque-change model predicted and reproduced human multi-joint movement data quite well (Uno et al. 1989). Here, we propose a neural network model for trajectory formation based on the minimum torque-change criterion. Basic ideas of information representation and algorithm are(i) spatial representation of time,(ii) learning of forward dynamics and kinetics model and(iii) relaxation computation based on the acquired model. The model can resolve ill-posed inverse kinematics and inverse dynamics problems for redundant controlled object as well as ill-posed trajectory formation problems. By computer simulation, we show that the model can produce a multi-joint arm trajectory while avoiding obstacles or passing through viapoints.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00201442
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  • 9
    Electronic Resource
    Electronic Resource
    The mechanism of mental scanning in foveal vision (1978)
    Springer
    Biological cybernetics 30 (1978), S. 147-155 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract In order to perceive a visual pattern which includes several elemental pictures, the perceiver must allot his cognitive resources to suitably selected parts of the pattern and scan them in sequence. Even when the visual field is small and eye-movement is not required, such scanning is found. We called it ‘mental scanning’ and performed psychological experiments to investigate the mechanism. The tasks were to discern whether the elemental pictures in a pattern are all the same (SP) or not (DP). The per cents correct of the task were measured for various exposure durations. We defined the threshold as the exposure duration at which 75% correct answers were obtained. Our main findings are as follows. The threshold for SP is proportional to the number of picture elements, while the threshold for DP is constant. It appears that two modes of mental scanning exist. One is serial processing for SP, and the other is parallel processing for DP. We proposed a two-layered neural network model having the following characteristics. 1) Information is transmitted as two types of signals through two separate channels; one is the transient signals to the Y layer and the other is the sustained signals slowly conducted to the X layer. 2) Interactions among neurons in the Y layer are lateral inhibitory, while those in the X layer are self-excitatory and lateralinhibitory. 3) Every neuron in the Y layer sends inhibitory signals to every neuron in the X layer except one with the same receptive field. Under these conditions, the dynamics of neurons in the X layer is represented by a set of certain equations. From phase plane analysis and numerical integration, the model appears to have an ability to account for various experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00337143
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  • 10
    Electronic Resource
    Electronic Resource
    Biological oscillators can be stopped—Topological study of a phase response curve (1978)
    Springer
    Biological cybernetics 30 (1978), S. 241-248 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Many biological oscillators are stable against noise and perturbation (e.g. circadian rhythms, biochemical oscillators, pacemaker neurons, bursting neurons and neural networks with periodic outputs). The experiment of phase shifts resulting from discrete perturbation of stable biological rhythms was developed by Perkel and coworkers (Perkel et al., 1964). By these methods, they could get important insights into the entrainment behaviors of biological rhythms. Phase response curves, which are measured in these experiments, can be classified into two types. The one is the curve with one mapping degree (Type 1), and the other is that with zero mapping degree (Type 0) (Winfree, 1970). We define the phase response curve mathematically, and explain the difference between these two types by the homotopy theory. Moreover, we prove that, if a Type 0 curve is obtained at a certain magnitude of perturbation, there exists at least one lower magnitude for which the phase response curve cannot be measured. Some applications of these theoretical results are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00361045
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