Relapsing myelitis.
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Adrenal Cortex Hormones↗
Biomedical subjects
I Ziv
Publications and source records attributed to I Ziv.
Human facet cartilage: swelling and some physico-chemical characteristics as a function of age. Part 1: Swelling of human facet joint cartilage.
The hydration of cartilage from human facet joints was measured after the joints had been subjected to different treatments. One group of facets was opened and directly exposed to physiologic saline solution before extraction of cartilage plugs. The plugs were weighed, re-equilibrated in fluid, and weighed again. The swelling results obtained under these conditions were compared with those when similar plugs of cartilage were excised from joints that had not been exposed to solution or had been exposed to solution while still closed. It was found that swelling was least (and similar in value to hip cartilage) for joints that had been exposed open to saline solution, highest for joints that had not been exposed to solution, and intermediate for joints that had been exposed to solution while still closed. The same trends were observed whether the cartilage on the joint was intact or fibrillated, although in each group the swelling and the final hydration were higher for fibrillated than for intact tissue. It was concluded that facet cartilage, unlike human hip or knee cartilage, is underhydrated when excised from the joint. This underhydration is thought to reflect the permanent presence of stresses in vivo on some part of the facet joints, the position of the loaded site changing with time. The authors attempted to distinguish between the swelling caused by this underhydration and that from disruption of the collagen network in the case of fibrillated specimens.
Aging↗
Effects of food and mates on time budget in Aplysia fasciata: integration of feeding, reproduction, and locomotion.
This study examines the time budgeted to different behaviors in Aplysia fasciata under three conditions: (1) animals have constant access to food and mates: (2) there is access to food, but not to mates; (3) neither food nor mates are present. The data suggest a number of rules underlying behavioral integration: (1) Feeding, reproductive behaviors, and activity seem to be natural categories for behavioral choice. Feeding and reproductive behaviors are controlled in tandem by a common arousal mechanism, while time left over after animals feed and reproduce is distributed in a fixed ratio between locomotion (crawling and swimming) and inactivity (immobility and movement in place). (2) Relative distribution between different forms of locomotion and inactivity is modified by changes in motivational state. More time is spent swimming than crawling when feeding and/or mating is prevented, while more time is spent moving in place than immobile when the arousal level is increased. (3) Feedback control of feeding and reproduction is asymmetric. Satiation of feeding inhibits the common arousal. In the absence of food, time spent on reproductive behaviors increases due to disinhibition of the common arousal. By contrast, positive feedback arising from sexual behavior excites the common arousal. When mating is prevented by removing potential mates, time spent feeding decreases. (4) Generally, animals choose between performing the three main categories of behavior. Although Aplysia simultaneously can feed and mate, or locomote and mate, they do so infrequently. By contrast, different types of reproductive behaviors (male mating, female mating, egg-laying) are commonly performed simultaneously.
Animals↗
Daily variation of multiple behaviors in Aplysia fasciata: integration of feeding, reproduction, and locomotion.
Daily variations in feeding, reproductive behaviors, and activity level were examined under three conditions: (1) animals had access to food and mates; (2) there was access only to food; (3) neither food nor mates were present. Behaviors differed in amplitude of variations from their daily mean value. Egg-laying had the strongest tendency to be clustered. Amplitude of variations in courtship and swimming was larger than those of immobility, crawling, and feeding, while moving in place was the least clustered behavior. Changes in state affected the tendency to be clustered. When food and mates were present, amplitude of variations became progressively larger for immobility, moving in place, crawling, and swimming. Behaviors differed in the degree to which variations were patterned as a 1/day oscillation. Relatively little of the variability in crawling, moving in place, courtship, and egg-laying was due to a 1/day oscillation under any condition. By contrast, a large proportion of the variability of immobility, swimming, mating, and eating was modulated by a 1/day oscillation in at least one condition. The contribution of a 1/day oscillation to variability differed in the conditions examined. For immobility and swimming, when food and mates were present, the 1/day component of variability became smaller. By contrast, presence of mates led to an increase in the 1/day component of variability modulating feeding. Daily peaks of swimming and feeding were in phase with one another, and out of phase with mating and feeding. The ratio of locomotion to inactivity is constant, independent of change in external conditions. However, this ratio varied throughout the day. When food and mates were absent, variations of immobility and swimming were strongly related to variations in the inactivity ratio. When food and mates were added, this tendency decreased. The data suggest that daily variations in occurrence of behaviors can be accounted for by interactions between oscillators affecting Aplysia behavior and motivational variables. A 1/day oscillator has strong effects on mating, swimming, and immobility. The effect of the oscillator is modified by changes in motivational state.
Animals↗
Effects of conspecifics on feeding in Aplysia fasciata.
The presence of other Aplysia in the environment increases the time spent feeding. This finding is consistent with the hypothesis that a common arousal mechanism modulates feeding and reproductive behaviors. The arousal level is presumably increased by pheromones released by additional animals.
Animals↗
Common regulation of feeding and mating in Aplysia fasciata: pheromones released by mating and by egg cordons increase feeding behavior.
We examined whether pheromones released by reproductive behaviors (mating and egg-laying) affect feeding behavior. A preliminary experiment demonstrated that the quantity of food eaten can be used to measure the effects of pheromones on feeding. Using this measure, we then showed that Aplysia that were prevented from mating, but that were in the same aquarium as mating conspecifics, eat more food than do Aplysia in a medium lacking mating animals. Mating and feeding were not temporally correlated, indicating that pheromones released by mating probably do not initiate feeding, but rather modulate feeding after it has begun. Aplysia that were in the same aquarium as freshly deposited egg cordons also ate more than did animals in a medium lacking eggs.
Animals↗
Sequencing of behaviors in Aplysia fasciata: integration of feeding, reproduction, and locomotion.
To begin studying the neural basis of higher-order decision-making in Aplysia fasciata, we examined individual bouts of behavior in various conditions of access to food and/or mates. We then determined rules governing transitions between bouts. The data indicate that a single intermediate condition, moving in place, may be centrally related to transitions between behaviors. In all conditions, over 85% of all transitions between behaviors were via moving in place. Moving in place tended to precede and follow other categories of activity (crawling, swimming, immobile), and feeding. Also, moving in place apparently represents a fixed proportion of all bouts of behavior. In each condition, moving in place represented approximately 40% of all bouts, while the number of bouts of other behaviors varied markedly. After a bout of moving in place there was a strong tendency for the animal to return to the behavior performed before moving in place. Additional preferred sequences of behavior were also seen. Courtship tended to precede mating, and crawling preceded swimming.
Animals↗
Oscillations of cortical oxidative metabolism and microcirculation in the ischaemic brain.
A new in vivo model for studying brain metabolic and haemodynamic oscillatory phenomena during ischaemia is described. In this model acute or chronic occlusion of one or two carotid arteries in the rat is performed. Due to the partial ischaemia developed, oscillations in the level of intramitochondrial pyridine nucleotides (NADH) as well as flavoproteins (Fp) were recorded from the brain by monitoring the fluorescence of these respiratory chain components. The two fluorescent signals (NADH and Fp) were measured by using the time sharing or DC fluorometer/reflectometer. The changes in the reflected light at the excitation wavelengths (366 and 450 nm) were recorded simultaneously. Bilateral carotid artery occlusion induced immediate oscillations (6-9 waves per min) in the mitochondrial redox state as well as in tissue blood volume in both hemispheres. To verify the accuracy of the NADH monitoring system, including the correction technique for haemodynamic and other artifacts, we used the intracarotid artery saline bolus injection approach. The results could be summarized as follows: (1) unilateral carotid artery occlusion resulted in delayed development of oscillations, particularly in the ipsilateral hemisphere; (2) the oscillation phenomenon was reversible if recirculation restarted within 5 min. Occlusion for more than 30 min resulted in irreversible oscillations; (3) the oscillation appearances and intensities were affected by various physiological conditions. Vasoconstriction, induced by hyperoxia, stimulated the oscillations while vasodilation, induced by hypercapnia, depressed them. Anoxia, hypoxia and spreading depression (SD) abolished the oscillations. Glucose injection was not effective.(ABSTRACT TRUNCATED AT 250 WORDS)
Anesthetics↗
Osteoid osteoma of the scapula. A case report and review of the literature.
The scapula is a rare location for osteoid osteoma, which in most cases does not involve the flat bones. The en bloc excision in this uncommon location can be problematic since the surgical exposure is difficult, and shoulder joint function can be affected if the lesion is subchondral. In an 18-year-old man, an osteoid osteoma was located in the subchondral area of the glenoid. A guided needle biopsy of the nidus resulted in complete healing. This mode of treatment, with proper follow-up examination, is acceptable for a benign lesion situated in a problematic location.
Adolescent↗
[Aluminium and Alzheimer's disease].
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Aluminum↗
[Dexamethasone treatment in acute bacterial meningitis].
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Acute Disease↗
Spondylosis in sand rats: a model of intervertebral disc degeneration and hyperostosis.
This study defines gross, histopathologic, and radiologic changes associated with intervertebral disc degeneration in a spontaneously occurring form of the disease in aging sand rats (Psammomys obesus). Sand rats (male/female) fed lab chow supplemented with desert salt bush were sacrificed at periods of 3-30 months. Lateral thoracolumbar spine films were obtained. At sacrifice, spines were surgically exposed and gross findings were recorded; after fixation/decalcification, histopathologic studies were carried out using hematoxylin and eosin, and Safranin-O with fast green counterstain. Metabolic studies included correlations of pathologic and radiologic findings with blood glucose and insulin levels. Disc-space narrowing and subchondral endplate sclerosis increased radiologically with age, with more severe lower lumbar disc lesions. Ligamentous calcifications ventral to involved discs and caudal vertebrae were common. Disc thinning and anterior vertebral bony/cartilaginous spurs were more marked with age. Microscopy revealed loss of nucleus pulposus physaliform cells, chondrocyte replication, disc necrosis, and ossification. Hyperglycemia with and without hyperinsulinemia was common. No statistically significant differences in pathologic findings were noted, neither in diabetic versus nondiabetic nor in hyperinsulinemic animals. The sand rat is a model of disc degeneration; similarities with possible overlap with diffuse idiopathic skeletal hyperostosis syndrome were noted.
Aging↗
Optimal needle length of automatic injectors.
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Adolescent↗
Defining the viability of avulsed skin flaps by the split-thickness skin excision (STSE) test.
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Humans↗
Immediate care of crush injuries and compartment syndromes with the split-thickness skin excision.
Prospective evaluation of the one-stage procedure in 32 patients who suffered from 37 severe friction-avulsion injuries was carried out. Most injuries (81%) were in the lower extremity. Split-thickness skin excision was used for immediate diagnosis of flap vascularity and wound coverage. Split-thickness skin was harvested from the avulsed flap surfaces after they were temporarily sutured back to their original bed. Dermal capillary bleeding served as an indicator for tissue viability, thus delineating a clear line for debridement. All compartments were decompressed, and debridement of all devascularized tissues was performed. Most fractures were fixed with interfragmentary screws and external fixators. Viable parts of the avulsed flaps were sutured back to their original bed and exposed bones were covered with transposed muscles. Skin defects were grafted with the split-thickness skin that was harvested in the first stage and was meshed 1:3 to allow drainage. Most patients (26 out of 32) had only one surgical procedure for their extensive injuries. The split-thickness skin excision is effective in the establishment of debridement borders and helps in saving maximal viable flap area (49.4%). All wounds healed with no major wound complications. The split-thickness skin excision can be used immediately in the care of severe crush injuries, compartment syndromes, and open fractures as a one-stage procedure with the following advantages: (1) reliable diagnosis of flap vascularity, (2) immediate wound coverage with the possibility of drainage, (3) elimination of further debridements procedures, (4) elimination of distant skin donor wounds, and (5) less hospitalization.
Adolescent↗
Motivational control of sexual behavior in Aplysia fasciata: sequencing and modulation by sexual deprivation and by addition of partners.
Variables similar to those affecting feeding behavior also modulate sexual behavior in Aplysia fasciata, indicating that mating is under motivational control. Motivated behaviors are often patterned into appetitive and consummatory components. Courtship, the appetitive phase of male sexual behavior, was temporally related to subsequent mating. Although many bouts of courtship failed to lead to mating, most incidents of mating were preceded by courtship. Motivation is also characterized by satiation after the goal of the behavior is achieved. We found an increase in likelihood to mate following a period of sexual isolation. Motivated behaviors are also modulated by environmental stimuli that induce arousal. Time spent mating was found to be a function of the number of potential mates accessible for mating. Number of A. fascinata participating in a mating group was also found to be a function of number of potential mates available.
Animals↗
Crush injuries of the foot with compartment syndrome: immediate one-stage management.
Severe crush injuries with compartment syndrome were treated in five patients by an immediate one-stage procedure. This procedure included the assessment of skin flap viability with accurate debridement of devascularized tissues. It was performed according to the split-thickness skin excision technique. Compartment pressures were measured and the fasciotomies were performed through open wounds or separate medial and lateral incisions. The medial incision was extended to release the tarsal tunnel. Fractures were reduced and internally fixed and exposed bones were covered with locally transposed muscles. Skin grafts, taken earlier for the skin viability assessment, were meshed and applied to replace skin loss. All wounds and fractures healed uneventfully with no major functional loss. In multiple trauma, the physician should maintain a high index of suspicion for early diagnosis and treatment of severe foot injuries. Early treatment leads to more desirable results, shorter hospitalization, and faster rehabilitation.
Adult↗
Split-thickness skin excision in severe open fractures.
Split-thickness skin excision can be used as a one-stage procedure for the accurate diagnosis of flap viability and the immediate treatment of friction-avulsion injuries in severe open fractures. After cleaning the wound, the avulsed flap is temporarily sutured back to its original bed and a split thickness graft is taken from it and meshed to a 1:3 ratio. Surface dermal capillary bleeding then serves as an indicator of viability, clearly displaying a line for the excision of devascularized skin and correlating well with a concomitant fluorescein test. The wounds are re-opened and, after fixation of the fracture, the viable part of the flap is returned to its original bed and the remaining defects are covered with the meshed graft. We have treated 16 patients with extensive degloving injuries in this way, 15 needing only the single surgical procedure. All retained flaps survived, no other donor sites were needed and the split-thickness grafts took with 90% to 100% success.
Adolescent↗