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Query: UMLS:C0344329 (collapse)
 28,634 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a previous study of newborn infants we observed overall rib cage collapse during active sleep and postulated that the lungs also could be deflated, leading to reduced oxygen stores and circumstances favoring the rapid development of hypoxemia during apnea. In this study, thoracic gas volume (TGV) has been measured directly by occlusion plethysmography in six normal babies during behavioral quiet and active sleep and related to the different movements of the rib cage and abdomen-diaphragm that occur during each sleep state. TGV was significantly reduced in each baby during active sleep and was associated with rib cage deflation and increased abdomen-diaphragm excursions. The average reduction of TGV was 31% when compared with the volume in quiet sleep and did not depend on the order in which the sleep states were tested. The reduced lung volume in active sleep could have implications for the regulation of breathing in that state. A reduction of lung oxygen stores in active sleep suggests an age-related vulnerability of the young infant to hypoxemia.
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PMID:Reduced lung volume during behavioral active sleep in the newborn. 22 15

Fluorescently labeled desmin was incorporated into intermediate filaments when microinjected into living tissue culture cells. The desmin, purified from chicken gizzard smooth muscle and labeled with the fluorescent dye iodoacetamido rhodamine, was capable of forming a network of 10-nm filaments in solution. The labeled protein associated specifically with the native vimentin filaments in permeabilized, unfixed interphase and mitotic PtK2 cells. The labeled desmin was microinjected into living, cultured embryonic skeletal myotubes, where it became incorporated in straight fibers aligned along the long axis of the myotubes. Upon exposure to nocodazole, microinjected myotubes exhibited wavy, fluorescent filament bundles around the muscle nuclei. In PtK2 cells, an epithelial cell line, injected desmin formed a filamentous network, which colocalized with the native vimentin intermediate filaments but not with the cytokeratin networks and microtubular arrays. Exposure of the injected cells to nocadazole or acrylamide caused the desmin network to collapse and form a perinuclear cap that was indistinguishable from vimentin caps in the same cells. During mitosis, labeled desmin filaments were excluded from the spindle area, forming a cage around it. The filaments were partitioned into two groups either during anaphase or at the completion of cytokinesis. In the former case, the perispindle desmin filaments appeared to be stretched into two parts by the elongating spindle. In the latter case, a continuous bundle of filaments extended along the length of the spindle and appeared to be pinched in two by the contracting cleavage furrow. In these cells, desmin filaments were present in the midbody where they gradually were removed as the desmin filament network became redistributed throughout the cytoplasm of the spreading daughter cells.
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PMID:Visualization of intermediate filaments in living cells using fluorescently labeled desmin. 265 44

The optimal methods of prophylaxis and therapy of postoperative respiratory complications in surgical patients are still open to discussion. In spite of numerous recent clinical investigations, there is still no specific and universally acceptable therapeutic concept. In our department, we identify patients at risk of pulmonary complications by adequate screening, i.e. medical history, physical examination, chest X-ray, and spirometry. In the postoperative period there are a sequence of stages starting with early mobilization, respiratory therapy (including incentive spirometry and IPPB), and when necessary, controlled mechanical ventilation. We have measured and documented the flows and volumes required of patients using various types of incentive spirometer. In addition, we review on the literature and describe our experience with the technique, handling, and organization of sustained maximal inspiration (SMI). After thoracic or major upper abdominal surgery, all lung volumes decrease due to impairment of rib cage movement, changes in chest wall muscle tone, an increase in lung recoil, and airway closure. At the end of each expiration some of the smallest airways collapse either partly or totally. This process continues to some extent until, normally, a deep breath recruits the alveoli. Sighs to the limit of total lung capacity or oscillations of the expiratory baseline ought to be responsible for this effect in healthy humans; the same purpose is intended in incentive spirometry. For this therapy, it is mandatory that the central airways are not occluded by mucus and that the patient is able to breath volumes exceeding his normal tidal volume.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Postoperative respiratory therapy using incentive spirometry]. 265 75

Antihistamines are being increasingly administered in combination with various other agents, with adverse drug reactions the frequent result. The present study consisted of two experiments. Experiment 1 examined the toxicological response of rats to nicotine tartrate (0.0, 2.0, 4.0, and 8.0 mg/kg) in combination with either of two H1-histamine receptor antagonists, the ethylene diamine tripelennamine HCl (0.0, 16.0, 32.0, and 64.0 mg/kg) or the aminoethyl ether diphenhydramine HCl (0.0, 32.0, 64.0, and 96.0 mg/kg). Adult female rats received intraperitoneal injections when housed 12 per cage and toxicological response (number dead per group) was assessed 24 hours post-treatment. The results showed that over the dose ranges employed, and when given alone, nicotine was completely non-lethal, tripelennamine was virtually non-lethal and diphenhydramine was toxic only at the highest dose (5 of 12, at 96.0 mg/kg). However, when nicotine and the antihistamines were delivered in combinations, the toxicological response was markedly altered. Tripelennamine in combination with nicotine yielded supra-additive interaction, with the degree of potentiation being a simple linear function of nicotine within each dose of tripelennamine. The interaction between nicotine and diphenhydramine was more complicated, with certain dose combinations yielding supra-additivity, yet with others yielding antagonism. It was suggested that seizure-precipitated cardiopulmonary collapse was the immediate cause of death, plausibly mediated by central mechanisms. As such, Experiment 2 examined the influence of adding the proconvulsant pentylenetetrazole (PTZ) (0.0, 10.0, and 20.0 mg/kg) to nicotine (0.0, 2.0, 4.0, and 8.0 mg/kg)-tripelennamine (0.0 and 32.0 mg/kg) combination treatments. Effects were assessed both at 1.0 and 24.0 hours post-injection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Supra-additive toxic interaction of nicotine with antihistamines, and enhancement by the proconvulsant pentylenetetrazole. 285 8

Two cases of fractures of the sternum and T12 vertebra are presented, which appear to be a characteristic combination of injuries to farmers when hay bales fall on them. The mechanism of injury proposed is a severe forward flexion, producing vertebral collapse at the dorsolumbar junction, and fracture of the sternum from direct trauma against the steering wheel. These fractures should always be suspected in persons injured while baling hay. It is proposed to call this complex of injuries hay balers' fractures. Preventive measures suggested are: operator caution when hay bales are lifted; addition of locks to the loader forks; increasing the size of the loader, or placing a screen or cage over the operators to keep hay bales from falling on them.
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PMID:Hay balers' fractures. 670 48

The ultrasonographic features of osteogenesis imperfecta lethalis (OI Type II), including those not reported previously (*), are: In the skull: *Abnormal compressibility of the vault by the transducer, which may alter measurements of biparietal diameter. *Unusually good visualization of the orbits. *Increased visualization of arterial pulsations. *Increased through-transmission of the ultra-sound beam due to extremely poor mineralization. In the remainder of the skeleton. *Diminished visualization and increased through-transmission of the remainder of the skeleton, particularly of the spine, ribs and long bones due to defective mineralization. *Abnormally short limbs and poor visualization of the long bones due to defective mineralization. *Abnormally small thorax due to collapse of the rib cage. *Reduced fetal movement. Recognition of fetal fractures and deformities. Prenatal radiographs can be used to confirm the diagnosis and differentiate between osteogenesis imperfecta lethalis and other forms of neonatal dwarfism.
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PMID:The prenatal ultrasonographic diagnosis of osteogenesis imperfecta lethalis. 672 74

An infant born with multiplex congenita (Larsen's) syndrome developed respiratory distress 30 days following tracheostomy for relief of upper airway obstruction. The infant had structural and functional abnormalities of the thoracic cage. Tracheobronchoscopy revealed excessive compliance of the trachea with a tendency for collapse of the tracheal rings and obliteration of the tracheal lumen. Continuous positive airway pressure in the range of 20-25 cm H2O was used to maintain patency of the tracheal lumen and assure adequate ventilation. Hemodynamic and pulmonary barometric complications often observed when high levels of positive airway pressure are utilized in infants were not observed.
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PMID:Tracheomalacia in an infant with multiplex congenita (Larsen's) syndrome. 727 Nov 38

The complex anatomy of the vertebrate larynx shows a steady progression from the simple slit on the floor of the lungfish's pharynx to the fine-tuned mechanism of the human vocal apparatus. The frog's larynx acts as a check valve to prevent collapse of the lungs during a dive, since the animal has no rib cage. The crocodile's laryngeal framework has acquired an epiglottic analogue which fits snugly into the nasopharynx and protects the lower respiratory tract from inundation while the animal drowns its prey. The snake's larynx lies intraorally and can be extended beyond the lower teeth while the reptile leisurely swallows its prey intact. The mammal has acquired a cricothyroid joint, allowing its membranous vocal folds to be stretched during phonation. In Homo sapiens, vocal performance has reached its highest degree of versatility, with a vocal fold capable of adjustment in length, tension and shape. In the course of organic evolution, man appears to have chosen the ability to speak and sing over the security that an intranarial epiglottis would have given him.
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PMID:Joseph H. Ogura Memorial Lecture. The vertebrate larynx: adaptations and aberrations. 841 62

Problems associated with posterior lumbar interbody fusion (PLIF) have traditionally included the need for donor bone, prolonged healing time of donor bone, the difficulty of cutting precise bony channels, the risk of retropulsion of graft, postoperative collapse of the bone graft, and pseudarthrosis. To avoid these problems a carbon fiber reinforced polymer implant cage has been developed to facilitate interbody fusion. The aim of the present study was to evaluate the technical problems and fusion rate associated with these new device for PLIF. Between April 1991 and December 1993, 65 pairs of these implant cages were sold in Sweden. They were traced to six hospitals, where they had been used in the treatment of 51 patients operated on at a total of 65 levels. All PLIF were supplemented with VSP (Variable Screw Placement) instrumentation. All medical records were evaluated and all patients were examined with plain radiographs taken at least 1 year after surgery. If that investigation did not show a clear fusion they were also evaluated with CT (18 patients, 27 levels). No intraoperative problems with the device have been reported; 44 patients (86%) and 58 levels (89%) achieved successful fusion. All patients bar one maintained their immediately obtained postoperative disc height. CT with 1-mm slices and sagittal reconstruction is most helpful if radiographs are difficult to interpret.
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PMID:Fusion rate after posterior lumbar interbody fusion with carbon fiber implant: 1-year follow-up of 51 patients. 883 Nov 20

The breaking of the interalveolar septa represents, in the pathogenetic mechanism of emphysema, a final event, common to the different etiologic agents. This elementary injury causes a series of consequences, essentially of mechanic-structural type (intrapulmonary aerial spaces-confining parenchyma collapse, bronchial obstruction, dead space augmentation) on the thin and articulate bronchoalveolar architecture, whose final rearrangement determines, at least in part, the clinical picture. In short, the break of alveolar septa involves the formation of intraparenchymal aerial spaces with collapse of the confining lung; the compensatory mechanism to this situation, involves the hyperexpansion of the thoracic cage and flattening of the diaphragm, with the aim of allowing ventilation of the healthy residual parenchyma. Because of the finite capability of expansion of the thoracic cage and of the diaphragm in respect to the theoretical capability of the lung of large intraparenchymal aerial spaces formation, it is easy to imagine that emphysema can cause a serious functional respiratory deficit even before a significant quantity of pulmonary parenchyma is destroyed by the pathogenic process. It may then be hypothesized that a simple reduction of the volume of the lung, even sacrificing a part of "working" parenchyma, might allow the residual lung to come back to a normal ventilation, wholly ameliorating the respiratory exchanges. The clinically more remarkable consequence of lung volume reduction is the amelioration of ventilation mechanics with a decreased respiratory work due to the shift of the tidal volume toward values less proximal to the maximal expandability of the thoracic wall and of the diaphragm. On the other end, it is possible to anticipate an equally significant effect on bronchial obstruction, due to the more favorable matching of the compliance of the thoracic wall and that of the lung. LVRS has significant effect on the TV sharing ratio between emphysematous spaces and residual healthy parenchyma; the hyperexpansion of the residual lung in fact causes the distension of the emphysematous spaces, continuing in the natural compensatory mechanism of the emphysema. The decreased ventilation and thus re-breathing of the residual emphysematous spaces, together with the improved ventilation may ameliorate hypercapnia. Obviously no direct effects can be expected from LVRS on the conditions of the alveolar membrane and thus on gas diffusion capacity through it. The time duration of the amelioration achieved with the lung volume reduction is still to be demonstrated.
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PMID:[The surgical physiopathology of essential pulmonary emphysema and volume-reduction intervention]. 997 94


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