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At least 1,405 records · Page 78Linked to original sources
PubMed1984

[Indications and significance of esthetic plastic surgery].

The motivations of aesthetic operations for achievement of a more harmonious appearance or for treatment of the external signs of aging are, besides purely aesthetic reasons, the desire to increase professional opportunities, to better adapt to the social environment or to improve affective relations. Aesthetic surgery has therefore a mainly psychic indication: the aim is to improve the self-esteem, which, on the other hand facilitates the social integration. A responsible execution of aesthetic surgery requires, besides a basic knowledge of psychology and sensitivity for aesthetics, a complete training in general surgery and in reconstructive plastic surgery as well as a continuing education in the aesthetic field. It is therefore not advisable to divide the specialty of plastic surgery. The advancements in both fields have a mutual positive influence and both have to consider function as well as appearance, although with different emphasis. The adequate treatment of eventual complications also requires a basic knowledge in both fields. The intensive advertising made by commercial, so-called "cosmetic clinics" is in contrast to the plastic surgeon's possibilities of public relations, restricted for ethical considerations. Undoubtedly it is not sufficient, at least on a medium-term basis, to achieve better results--in benefit of the patient--unless this is also made known to the public. The necessary information of the public should therefore be taken over or be directed by the National Societies of Plastic Surgery, on an anonymous basis.

Adaptation, Psychological↗
PubMed1983

[On a newly modified method for plastic reconstruction of the face using the skull (based on Kollman data)].

Since Kollmann & Büchly (1898) presented for the first time a plastic reconstruction of the face on the skull, which was based on empiric data, this method has been improved continuously. Up to now, however, doubts on its reliability could not be removed completely. While in the meantime the reconstruction of the large organs of the face could be based on a more secured empiric basis, this was not possible concerning the remaining surface of the face. This could be surmounted using the measurements of the soft parts of the living body (34 items) proposed by Helmer (1980). Basing on these measurements the author presents a newly modified method for the plastic reconstruction of the face on the skull. Among others he accepts as basic pattern the principle of parallel profile lines suggested by Helmer (to identify skulls by means of superposition of electronic pictures). By that the author is of the opinion that he has improved the possibility of verifying and reproducing acquired results. It is recommended to fill still uncertain methodological gaps by distinct working hypothesis. However, on plastic reconstructions unclear details should be treated in such a way that they are standing out against the remaining surface. The potential scope of the plastic reconstruction of the face on the skull has been limited by Helmer's method (identification of skulls), but is basically still unchanged.

Cephalometry↗
PubMed1983

Microsurgery and the community-based plastic surgeon.

1. The majority of our residents who completed their training since 1974 use a microscope for nerve repairs. A majority of those doing microscopic nerve repairs also repair noncritical vessel injuries with the microscope. 2. Half of the respondents who completed training in 1974 or before do not use the microscope for any operative procedures. 3. Successful replantation or revascularization procedures are not uncommon early in the practice of a community-based plastic surgeon. The tendency is to do fewer of these procedures the longer the period of practice. 4. For most of the community-based plastic surgeons, the boundary line of community practice versus the University practice is at the level of replantation, revascularization, and free flaps. 5. This boundary was modified by the strategy of having a University microsurgeon (from the same respondent group) assist the community-based plastic surgeon on replants and free flaps in a community hospital. 6. All of the residents who completed training since 1978 used loupes on a frequent (daily or weekly) basis. 7. Only half of the residents who completed training before 1975 used loupes. 8. Other uses of the microscope in the community were vasectomy reversal, nailbed repair, individual transplantation of hairs for eyelashes, canaliculus repairs, and the prevention of traumatic tattoos. Otologic and laryngologic procedures were carried out under the microscope by two respondents who had had otorhinolaryngologic training prior to their plastic surgery residencies.

Amputation, Traumatic↗
PubMed1980

[The abrasion resistance of dental materials. 2. Improvement of abrasion resistance of tooth-colored plastics by means of combination with dental ceramics].

On the abrasion resistance of dental materials. Part II: Reduction of the abrasion of tooth-colored plastics as achieved by the simultaneous use of dental ceramic materials In vitro experiments showed that dental plastics being in contact with dental ceramic materials are abraded to a lesser extent than dental plastics in contact with dental plastics.

Dental Materials↗
PubMed1982

Plasticity in the oculomotor system.

The oculomotor system, responsible for the control of eye movement, is capable of a number of kinds of plasticity. The demonstration of such plasticity has been aided by several factors, including the present delineation of the system's major subsystems and their purposes; the relatively simple relationships between the system and the mechanical apparatus on which it acts, the eyeball and its muscles; and the development of techniques for studying central nervous system (CNS) activity in awake, behaving animals. Plasticity has been demonstrated by using noninvasive techniques to disturb the normal relationship between vision and eye movements, thereby creating a need for adjustment by the oculomotor system. Current studies are concerned with the location and identity of the responsible modifiable synapses. The cerebellum and the olivocerebellar pathways are definitely involved in several forms of oculomotor plasticity. However, it remains to be determined whether the responsible changes reside within these structures or are located elsewhere in the CNS.

Accommodation, Ocular↗
PubMedDate not supplied

Toxicity of plastic materials as evaluated by means of bull semen (preliminary report).

In the study preliminary results concerning the toxicological testing of plastics, applying a new biological method, are presented. The method worked out consists in the use of fresh, diluted bull semen and water extracts of plastics. The results of laboratory findings have demonstrated bull spermatozoa to be sensitive to slight amounts of toxic compounds contained even in some medical grade plastics. The described bull semen toxicity test is a new approach to the safety testing of plastic materials destined for medical and pharmaceutical purposes.

Animals↗
PubMed1981

Long custom-made plastic tracheostomy tube in severe tracheomalacia.

Tracheomalacia occasionally occurs after repair of esophageal atresia and distal tracheoesophageal fistula. It is usually mild, and tracheostomy is rarely necessary. In severe cases of tracheomalacia after repair of esophageal atresia and distal tracheoesophageal fistula, the tracheomalacia may extend below the tip of a regular plastic tracheostomy tube. A patient with just such a problem is presented. A custom-made long plastic tracheostomy tube was designed. A method of gluing the upper portion of a standard plastic tracheostomy tube to an uncuffed thin-walled polyvinyl chloride endotracheal tube was discovered and the technique is described in detail. The literature is reviewed concerning custom-made long plastic tracheostomy tubes and tracheomalacia in relation to esophageal atresia and distal tracheoesophageal fistula.

Esophageal Atresia↗
PubMed1994

Plastic-adherent cells in human bone marrow generate long-term hematopoiesis in vitro.

This study demonstrates that the human bone marrow mononuclear cell fraction that adheres to plastic during a 2-h incubation period includes stromal precursors and hematopoietic progenitor cells that can sustain hematopoiesis for at least 5 weeks in a long-term culture (LTC) system. Delta (delta) assays were performed on the 2-h plastic-adherent fraction of mononuclear cells, by assaying the numbers of CFU-GM released into the culture supernatant during 1 week of incubation, to investigate the properties of the original progenitor cells. The plastic-adherent delta (P delta) progenitor cells all express CD34, and a variable proportion express Thy-1. The numbers of CFU-GM produced are directly related to the numbers of mononuclear cells used to initiate the cultures, and limiting dilution experiments indicate a frequency for P delta cells of 2.5-10/10(5) mononuclear cells. The numbers of CFU-GM produced by individual P delta cells at limiting dilution vary considerably within experiments but the distributions of CFU-GM per P delta progenitor show little variation between samples. On average, P delta cells generate 6-9 early CFU-GM scored on day 21 of culture; 10-23 CFU-GM scored on day 14, and 18-40 mature CFU-GM scored on day 7. These results show that plastic-adherent cells in human bone marrow are capable of sustained hematopoiesis in vitro and of producing a spectrum of clonogenic progeny. They form the basis of an assay for investigating the kinetics of early human hematopoietic progenitor cells.

Antigens, CD↗
PubMedDate not supplied

[Development of a plastic capillary tube for Saling fetal blood analysis. Evaluation of pH-metry with standard references].

In order to avoid mouth suction and danger of glass breakage during collection and to avoid mixing of the sample with a piece of wire and an external magnet immediately after collection, an unbreakable plastic capillary tube was designed with increased heparin coating and surface and reduced diffusion distance. For assessing agreement between pH measurements of blood samples obtained with the new plastic capillary tube and a commercial glass capillary tube, umbilical blood pH-values of 41 births were analyzed simultaneously by both methods. The mean difference between paired pH-values, the corresponding 95%-confidence interval and the true limits of agreement were calculated. The pH-values obtained with the plastic capillary tube are systematically lower, with a mean pH decrease of 0.009 units, and there is an additional random variation with a standard deviation of 0.009 pH units. The true limits of agreement: [-0.031, 0.013] represent the interval of the worst expected pH difference. The increased heparin availability in the plastic capillary tube may be the reason for the systematic pH deviation of -0.009 units. However this difference does not seem to be clinically relevant and the statistical evaluation shows a sufficiently good agreement between the pH measurements.

Acid-Base Equilibrium↗
PubMedDate not supplied

[The effect of leukotrienes B4, C4, 12-hydroxyeicosatetraenoic acid and of the threo- and erythro-epimers of hepoxilin B3 on the plasticity of the neuronal cholinoreceptors in the snail].

Effects of several acyclic eicosanoids (which are formed from arachidonic acid under the action of 5- and 12-lipoxygenases) on desensitization of somatic cholinoreceptors of Helix lucorum RPa3 and LPa3 neurons were studied by means of two-electrode voltage clamp technique. The substances under study were: leukotrienes B4, C4, 12(S)-hydroxy-(5Z,8Z,10E,14Z)-eicosatetraenoic acid (12-HETE), threo- and erythro-epimers of hepoxilin B3. Cholinoreceptor plasticity was evaluated by a degree of depression of inward current, induced by rhythmical local ACh applications on the soma with intervals 55-180 sec. Leukotrienes B4 and C4 intensified cholinoreceptor plasticity. Inhibitor of inositol-1,4,5-trisphosphate-dependent (IP3-d) mobilization of deposited Ca2+, TMB-8, prevented the effect of leukotriene C4. 12-HETE, threo- and erythro-epimers of hepoxilin B3 did not change plasticity. A conclusion is made that cholinoreceptor plasticity is controlled by leukotrienes B4 and C4. One of the regulatory pathways includes IP3-d Ca-mobilization. Eicosanoids from 12-lipoxygenase pathway (12-HETE, threo- and erythro-epimers of hepoxilin B3) do not participate in this intracellular regulatory mechanism.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1994

Selection and preoperative preparation of plastic surgery patients.

There is no nursing specialty in which the marriage between physical and psychosocial care of the individual is so evident as in plastic surgery nursing. The patient's surgical outcome and adjustment to the body image change depend largely on nursing care. During the adjustment period, the patient is likely to confide in the nurse, and it is clear that the patient benefits from a knowledgeable and empathetic nurse. Nurses and patients have long recognized the value of nursing care in the treatment of the plastic surgery patient. As plastic surgery becomes more widespread in the next century, the unique skills of the plastic and reconstructive surgery nurse will be even more treasured.

Humans↗
PubMed1993

Reduction mammoplasty: comparison of results of plastic and general surgeons.

OBJECTIVE: To compare the results in patients who had reduction mammoplasty in a department of plastic surgery with those of patients who had the same operation in a department of general surgery. DESIGN: Retrospective study of casenotes, and questionnaire. SETTING: Department of Plastic Surgery, University Hospital, Linköping, and Department of General Surgery, County Hospital, Motala. SUBJECTS: All 250 patients who had undergone reduction mammoplasty during the five year period 1980-84 (Linköping, n = 173; Motala, n = 77). MAIN OUTCOME MEASURES: Correlation between symptoms and expectations, and the patients' subjective assessment of the results. RESULTS: There was no difference between the rates of response to the questionnaire (149/173, 86%, from those operated on in the department of plastic surgery compared with 68/77, 88%, in the department of general surgery). Median stay in hospital was 6 days in both groups, and the number of days of sick leave was 29 and 33 days, respectively. The most common histological diagnosis was hyperplastic breast tissue with or without fibroadenosis (149/173, 86%, compared with 64/77, 83%) and there was one carcinoma, which was detected before operation. The main reason for the operation in both groups was the weight of the breasts, which caused shoulder or back pain; in nearly half this interfered with activities of daily living. Most patients had high expectations of the operation, and in over 80% these were fulfilled. CONCLUSION: We could find no reason why reduction mammoplasty should not be done by general surgeons, particularly in view of the long waiting lists, but there are some groups (for example, young women and patients either with exceptionally large breasts or who require only small reductions) who should still be treated by specialist plastic surgeons.

Adult↗
PubMed1994

A day of day plastic surgery in a district general hospital.

In spite of the suitability of the day surgery environment for most patients undergoing elective plastic surgery, day plastic surgery has not been universally adopted in the United Kingdom. The experience of one plastic surgeon gained in treating 5970 patients as day cases out of a total of 12,461 patients over 10 years is described, with emphasis on the organisation of the service by only the consultant surgeon in collaboration with a medical secretary. Thus, neither the trainee surgeon nor GP clinical assistant in the team have any administrative duties. Within a day surgery unit with a twin theatre and 12 beds, it was possible on 1 day each week between July 1991 and June 1992 to treat 954 patients of whom 678 were treated under local anaesthesia and 276 under general anaesthesia. Three patients required admission to the main hospital overnight. By this day of day plastic surgery an effective service is provided to patients convenient to their home while also releasing facilities in the main regional centre which is equipped and staffed to a higher level of reconstructive expertise. However, the patients themselves should also play a part in improving the service intended for them, and a failure to attend for surgery without prior warning adds an avoidable element of inefficiency.

Adult↗
PubMed1995

Elementary forms of synaptic plasticity in the visual cortex.

The neocortex is an important site of memory storage, and memories are believed to be formed in the cortex by the activity-dependent modification of synaptic connections. However, in contrast to the hippocampus where there has been an increasingly sophisticated analysis of synaptic plasticity, relatively little is known about the mechanisms of synaptic modification in neocortex. Here we summarize the results of a series of experiments conducted on slices of visual cortex in vitro, aimed at elucidating the elementary mechanisms of synaptic plasticity in the superficial layers of neocortex. We show that long-term potentiation (LTP) and depression (LTD) result from high- and low-frequency conditioning stimulation, respectively, of the middle layers of cortex. Both forms of synaptic plasticity are input-specific and dependent on activation of postsynaptic N-methyl-D-aspartate (NMDA) receptors. The critical variable in determining the sign of the synaptic modification appears to be the level of postsynaptic depolarization during conditioning stimulation. The data support a model in which the state of correlation of pre- and post-synaptic activity is converted by the voltage-dependent NMDA receptor channel into a graded postsynaptic Ca2+ signal. LTD is triggered by a modest but sustained elevation in postsynaptic Ca2+, while LTP is elicited by larger changes in Ca2+. An important variable that regulates synaptic plasticity in the neocortex is intracortical inhibition, which constrains the patterns of activity that can reach the modifiable synapses in layer III.

Calcium↗
PubMed1994

[Proposal of JP standards for plastic containers for pharmaceuticals].

A new approach to standardization of plastic containers for pharmaceuticals in the Pharmacopoeia of Japan (JP) has been proposed, structured into the following three parts: (1) "Plastic Containers for Pharmaceuticals" in the GENERAL INFORMATION section that describes the general requirements and rationales for conformity; (2) "Test Methods for Plastic Containers" in the GENERAL TESTS section that describes various test methods applicable for verifying conformity; (3) Special requirements and/or limit values for special containers such as infusion bags in a MONOGRAPH section. New standards should be designed to cover plastic containers of any shape and volume made of any kind of material.

Drug Packaging↗
PubMed1996

Structural plasticity of the adult CNS. Negative control by neurite growth inhibitory signals.

The neuronal network of the adult central nervous system (CNS) retains a limited capacity for growth and structural change. This structural plasticity has been best studied in the context of lesion-induced growth and repair. More recently, structural changes underlying functional plasticity occurring under specific physiological conditions have also been documented, in particular in the cortex and the hippocampus. Areas known for their adult plastic potential retain high levels of the growth associated protein GAP-43, suggesting a persistence of important components of the intracellular growth machinery throughout life. Interestingly, a pronounced negative correlation exists between the levels of GAP-43 and myelination in the adult CNS. Because CNS myelin contains potent neurite growth inhibitory membrane proteins, neurite growth, sprouting and plasticity were investigated in the spinal cord and brain in areas where oligodendrocyte development and myelin formation was experimentally prevented, or in the presence of an inhibitor neutralizing antibody (mAB-IN-1). In all areas, lesion-induced or spontaneous sprouting was enhanced, in parallel with persistent high levels of GAP-43. Thus, spontaneous sprouting of side branches occurred from retinal axons in the optic nerve in the absence of myelin, and target-deprived retinal axons showed increased sprouting and innervation of the contralateral optic tectum in the presence of mAB IN-1. In experimentally myelin-free spinal cords collaterals from intact dorsal roots grew over long distances to innervate deafferented target regions following the section of three dorsal roots. Similarly, the corticospinal tract sprouted across the the midline and re-established a dense plexus of fibres on the contralateral side of the spinal cord following section of one corticospinal tract in juvenile rats. Following bilateral dorsal hemisection of the spinal cord including both corticospinal tracts in young and adult rats, long distance regeneration of corticospinal fibres leading to significant functional improvements of locomotion and certain reflexes was induced by the neurite growth inhibitor neutralizing antibody IN-1.

Age Factors↗
PubMed1996

Rapid tolerance to benzodiazepine modifies rat hippocampal synaptic plasticity.

Glutamate antagonists to N-methyl-D-aspartate (NMDA) receptors blocks the development of "rapid' tolerance to the sedative action of benzodiazepines (BZDs). This kind of glutamate receptors is closely related to synaptic plasticity in different areas of the brain such as hippocampus. In the present investigation, we studied the synaptic plasticity in dentate gyrus of the hippocampus during the development of tolerance to the hypomotility action induced by diazepam (DZ). The results show an increased hippocampal synaptic plasticity in slices from rats treated with diazepam (5 mg/kg per day) during 4 days, assessed as a decrease of the threshold in the stimulation frequency for long-term potentiation (LTP) elicitation. Thus, a single dose of DZ does not change the ease of induction of LTP but does change locomotor behavior: multiple DZ doses change LTP but not locomotor behavior. Our results reveal a positive correlation between the synaptic plasticity and development of BZD tolerance to locomotor activity.

Animals↗
PubMedDate not supplied

Adhesion of different Candida spp. to plastic: XTT formazan determinations.

Adhesion of synchronized yeast-phase Candida cells to tissue culture plastic was investigated using the tetrazolium salt, XTT. The procedure permits the direct enumeration of adherent yeasts following the metabolic conversion of the XTT tetrazolium salt, to its reduced formazan form, by mitochondrial dehydrogenases. Using this procedure, the formation of XTT formazan by Candida cells was typically related to the inoculum size. The adhesion of Candida yeast-phase cells from different Candida spp. to plastic was of the following order: C. krusei (n = 5) > C. albicans (n = 10) > C. glabrata (n = 6). Furthermore, preliminary experiments with several other species indicated that C. tropicalis (n = 2) may adhere as well as C. albicans and that one strain each of C. guilliermondii and C. parapsilosis appear to adhere to plastic in a similar fashion to C. glabrata. The data indicate the utility of the XTT tetrazolium based assay in enumerating the adhesion of different Candida spp. to plastic.

Adhesiveness↗