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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 119 (1994), S. 185-190 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A model that helps explain the mysterious long-distance migration of the Japanese eel (Anguilla japonica) is presented, based on oceanographic observations, satellite buoy drift experiments, and samplings of eel larvae taken in 1991. The trajectory of a 150 m depth buoy relased in the spawning area strongly suggests that A. japonica larvae spawned just south of the salinity front are transported westward by the North Equatorial Current (NEC). The larvae are then thought to be entrained into the Mindanao Current flowing southward along the Philippine Islands where A. japonica juveniles are scarcely distributed. These controversial results lead to the assumption that eel larvae are transferred from the NEC to the northward flowing Kuroshio, which distributes the eel larvae to the growth habitats of eastern Asia. In this eel larvae transfer model, a northward Ekman transport caused by trade winds plays an important role in explaining the wind-induced northward shift of the larvae together with the onset of diel vertical migration. Assuming that leptocephali greater than 20 mm initiate the vertical migration, a westward wind velocity greater than 5 to 10 m s-1 should be high enough to diminish the southward current velocity. When the physical and geophysical conditions — such as the salinity front for spawning activity, the water tunnel for westward larval transport, the Ekman transport by the trade wind for transfer of the larvae from the NEC to the Kuroshio, and the strong velocity of the Kuroshio for rapid transport to growth habitats — are well matched with the timing of the onset of vertical migration, large-scale eel migration could result.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 54 (1984), S. 266-274 
    ISSN: 1432-1106
    Keywords: Optic nerve ; Fiber count ; Axon diameter ; Myelin sheath thickness ; Albino and gray rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Comparative studies were made on albino and gray rats by measuring several morphological characteristics seen in cross-sections of the optic nerve. The total cross-sectional area of the optic nerve was about 30% smaller in the albino than in the gray rat, while the fiber density was 1.4 times higher in the albino than in the gray rat. The estimated total fiber count was about the same in the two strains: around 100,000 to 110,000 fibers. Except for a few unmyelinated fibers (less than 1%) all fibers were myelinated. Axon diameters of the optic nerve fibers were distributed in smaller values for the albino than for the gray rat, though the overall diameter range was similar (0.2–3.0 μm). The myelin sheath was also thinner in the albino than in the gray rat.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 51 (1983), S. 172-178 
    ISSN: 1432-1106
    Keywords: Uncrossed optic fibers ; Optic tract fiber counts ; Axonal cross section area ; Plasticity ; Synaptic delay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In albino rats with one eye removed at birth (NE rats), electron microscopic studies were made on the optic tract (OT) to count the fibers and to measure their thickness. In addition, experiments were made in NE rats to know the physiological properties of the optic pathway such as conduction velocity, synaptic delay and so on. The number of fibers in the OT of NE rats was compared with that constituting the crossed and uncrossed pathways of normal adult rats. In NE rats the fiber count increased by about 30,000 in the OT ipsilateral to the remaining eye while it decreased by about the same amount in the contralateral OT. The axonal cross section area of OT fibers was measured as an index for fiber thickness. No marked abnormalities were found in the OTs of NE rats with regard to the morphological dimension. Relay cells (P-cells) of the LGN were recorded by electrical stimulation of the optic pathway. The uncrossed projection of NE rats to the LGN was characterized by the following points: (1) P-cells responding to stimulation of the uncrossed fibers were encountered in NE rats much more frequently than in normal adult rats. (2) Synaptic delays assumed to be involved in trans-synaptic activation of P-cells by the uncrossed fibers were calculated at larger values than for P-cells activated by the crossed fibers in NE rats and normally grown rats.
    Type of Medium: Electronic Resource
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  • 14
    ISSN: 1432-1106
    Keywords: Thalamostriatal projections ; Putamen ; Caudate nucleus ; Posterior thalamus ; Superior colliculus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Projections from the posterior thalamic regions to the striatum were studied in the cat by the anterograde tracing method after injecting wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) into the caudalmost regions of the lateroposterior thalamic nucleus (caudal LP), suprageniculate nucleus (Sg) and magnocellular division of the medial geniculate nucleus (MGm). The results were further confirmed by the retrograde tracing method after injecting WGA-HRP into the regions of the caudate nucleus (Cd) and putamen (Put) where afferent fibers from the caudal LP, Sg and MGm were distributed. Fibers from the MGm, Sg or caudal LP were distributed mainly in the medial, middle or lateral part of the caudal half of the putamen (caudal Put), respectively. Although there was a considerable overlap, thalamostriatal fibers from the caudal LP terminated more caudally than those from the MGm. On the other hand, thalamocaudate fibers from the MGm, Sg and lateral part of the caudal LP overlapped with each other in the ventrolateral part of the caudal half of the caudate nucleus (caudal Cd). Fibers from the medial part of the caudal LP were distributed in the ventral part of the caudal Cd. In the superior colliculus (SC) of the cats with WGA-HRP injections in the caudal LP, retrogradely labeled neuronal cell bodies were mainly seen ipsilaterally in the superficial SC layer, and simultaneously, anterogradely labeled axon terminals were observed in the striatum. On the other hand, when WGA-HRP was injected into the Sg or MGm, labeled SC neurons were mainly located in the intermediate and deep SC layers. Thus, ascending impulses from the superficial SC layer may possibly be conveyed ipsilaterally via the caudal LP to the ventral and ventrolateral parts of the caudal Cd and the lateral part of the caudal Put, whereas those from the intermediate and deep SC layers may be relayed via the Sg and/or MGm to the ventrolateral part of the caudal Cd and the middle and medial parts of the caudal Put.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 26 (1984), S. 657-658 
    ISSN: 1432-1041
    Keywords: verapamil ; maternal milk level ; maternal blood level ; excretion of milk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 36 (1989), S. 575-578 
    ISSN: 1432-1041
    Keywords: bunazosin ; hypertension ; alpha1-adrenoceptor blocker ; blood pressure ; renal blood flow ; renal function ; renin ; aldosterone ; atrial natriuretic peptide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The renal and hormonal effects of the α1-adrenoceptor blocker bunazosin were examined in 6 patients with essential hypertension. Oral bunazosin for 4 to 12 weeks significantly decreased mean blood pressure by 10%, increased effective renal blood flow and creatinine clearance by 34% and 37%, respectively, the plasma norepinephrine concentration was elevated by 60%, and the plasma atrial natriuretic peptide level was lowered by 22%. The plasma renin activity and aldosterone concentration were unchanged. Thus, a moderate reduction in blood pressure was produced by bunazosin treatment while maintaining renal perfusion.
    Type of Medium: Electronic Resource
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  • 17
    ISSN: 1432-1041
    Keywords: Atrial fibrillation ; disopyramide ; thyrotoxicosis ; cardioversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Rhythm conversion in patients with post-thyrotoxic atrial fibrillation (AF) has been performed with disopyramide in order to evaluate the conversion rate and to test its effect on the maintenance of sinus rhythm after cardioversion. The duration of AF ranged from 9 to 122 months (mean 31.8 months). Of 81 patients, 12 (15%) with relatively short duration AF were converted to sinus rhythm with disopyramide. The remaining 69 patients required DC cardioversion, which restored sinus rhythm in 58 patients. The 58 DC-converted patients were divided into two groups: a disopyramide group (D group) and a non-disopyramide group (non-D group). The D group received disopyramide 300 mg per day for 3 months after DC cardioversion and the non-D group did not receive anti-arrhythmic drugs. During the early observation period, only one patient relapsed in the D group into AF, but 5 successive patients in the non-D group reverted to AF, forcing discontinuation of the non-D protocol. A second DC cardioversion performed on 3 of those 5 patients was followed by maintenance therapy with disopyramide 300 mg per day, and they remained in sinus rhythm. With the inclusion of those three subjects, sinus rhythm was still present in 44 of the total of 58 patients converted by DC (76%) at the time of follow-up (64 months). Thus, disopyramide was effective in rhythm conversion and it was essential for the maintenance of sinus rhythm after cardioversion in patients with post-thyrotoxic AF.
    Type of Medium: Electronic Resource
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  • 18
    ISSN: 0942-0940
    Keywords: Tumour consistency ; meningiomas ; MRI ; T 2-weighted image
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The findings on magnetic resonance imaging (MRI) in 73 surgically verified intracranial meningiomas were correlated with their histology and consistency during resection. T 1-weighted imaging was least useful since most of the tumours were iso-intense, similar to cortical grey matter regardless of histology or tumour consistency. The signal intensity on T 2-weighted images was found to best correlate with both the histology and consistency of the meningioma. Generally, the low intensity portion of the tumour on T 2-weighted images indicated a more fibrous and harder character, while the higher intensity portions indicated a more soft character. Most of the fibroblastic meningiomas showed the features of a hard tumour while angioblastic tumours showed the features of soft tumours. Tumours predicted to be harder on MR imaging generally took longer to resect than softer ones, and this relationship was shown best for the larger tumours. Using linear regression analysis, it appears that operative time for soft tumours is more affected by factors other than tumour consistency. Blood loss during surgery was also unrelated to the consistency of the tumour. These results suggest that the histology and consistency of meningiomas may be predictable from findings on T 2-weighted imaging, and this may also predict the difficulty and time required for resection.
    Type of Medium: Electronic Resource
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  • 19
    ISSN: 0942-0940
    Keywords: Brain death ; hypothalamic hormone ; hypothalamic-pituitary system ; pituitary-hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Hypothalamic hormones as well as anterior pituitary hormones were detected in the peripheral plasma after the diagnosis of brain death. It is possible that residual hypothalamic tissue was functioning after satisfying the usual criteria of total brain death. To examine this possibility, endocrinological and morphological alterations of the hypothalamic-pituitary system was evaluated in 28 brain dead patients. Intrinsic ADH was depleted in the plasma shortly after the diagnosis of brain death. Anterior pituitary hormones were initially detected in all patients, but gradually disappeared. The direct TRH (thyrotropin releasing hormone) stimulation to the anterior lobe was responded to well. Morphological studies showed a partial necrosis of the anterior lobe and the preservation of the posterior lobe for as long as a week. These data prove that the pituitary is partially preserved after brain death. LH-RH (luteinizing hormone releasing hormone) was detected in the peripheral plasma of all patients and GRF (growth hormone releasing factor) was detected in half of the patients for as long as 15 days, but autopsy revealed the fact that the brain tissue including the hypothalamus became extensively necrotic after the sixth day of brain death. In order to solve this controversy it is proposed that these hormones originate from extracranial tissues such as pancreas. The detection of hypothalamic hormones after the diagnosis of brain death therefore is not contradictory to the concept of total brain death.
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Acta neurochirurgica 86 (1987), S. 111-114 
    ISSN: 0942-0940
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report a new experimental model for the study of hydrocephalus. Hydrocephalus was produced in C 57 black mouse by transplanting human glioma cultured cells. 20% of the animals developed hydrocephalus while the incidence of spontaneous hydrocephalus is only 1%. The transplanted cells disappeared within 72 hours. The mouse developed progressive hydrocephalus. There was no evidence of blockage of CSF pathways. The only abnormal microscopic finding was a scattered collection of lymphoid cells in some of the animals, which may be a hypersensitivity reaction to the cells. A similarly hypersensitive reaction to the foreign maternal protein which may enter the foetal circulation is suggested as the cause of hydrocephalus in some of the cases of congenital hydrocephalus.
    Type of Medium: Electronic Resource
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