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Biomedical subjects

A Pfister

Publications and source records attributed to A Pfister.

At least 19 recordsLinked to original sources
PubMed1992

Melanotic neuroectodermal tumor of the skull and meninges in infancy.

Three cases of melanotic neuroectodermal tumors of infancy are presented. Two were localized on the midline, involving the skull and extending subdurally. One was located on the inner aspect of the dura and developed intracranially. Two had a benign course following gross total removal. One had a malignant course, recurring locally and spreading within the brain. The difficulties of removing these tumors when they are implanted on the midline are stressed. Histological features of prognostic value are pointed out. Further support for neural crest origin of these tumors is given.

Child, Preschool↗
PubMed1991

Effect of long-term infusion of platelet-activating factor on pulmonary responsiveness and morphology in the guinea-pig.

The effect of chronic administration of platelet-activating factor (PAF) on airway reactivity, cell recruitment and lung morphology in the guinea-pig has been investigated. Alzet osmotic minipumps delivering either PAF (7.2 mg/kg/14 days) in 0.25% (w/v) bovine serum albumin in saline (saline-BSA), acetylcholine or saline-BSA alone were implanted s.c. in the neck region of guinea-pigs and connected to the jugular vein. In some experiments, implanted and non-implanted animals were treated daily with the PAF antagonist, BN 52021 (15 mg/kg, twice a day, p.o.). On day 15 after minipump implantation, the animals were anesthetized with urethane (1.2 g/kg, i.p.) and tracheal cannula was inserted for mechanical ventilation. Pulmonary inflation pressure (PIP) was monitored and airway responsiveness was assessed by administration of increasing doses of histamine (0.2-100 micrograms/kg, i.v.). As compared to saline-BSA-treated or non-implanted guinea-pigs, chronic treatment of the animals with PAF induced a significant (p less than 0.01) increase in airway response. No significant change in airway responsiveness was observed following chronic acetylcholine administration. In contrast, regardless of the treatment of the animals, no change in the threshold dose of histamine inducing alteration in PIP was noted, suggesting that PAF induces bronchopulmonary hyperreactivity rather than hyperresponsiveness. In addition, no significant difference was observed in the in vitro responsiveness to histamine of lung parenchymal strips from animals having received PAF or saline-BSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Treatment of fresh muscle injury].

A prospective double-blind randomized study comparing the results of a protein-free-haemodialisate (Actovegin) with placebo was performed in 103 patients. There has been 68 patients in the haemodialysate group. In acute muscle injuries we find a dent in the muscle and a loss of function. There has been three injections in the injured muscle every three to four days. The follow up examination occurred at least three months after the beginning of the study. Full sports activity was reached in the haemodialysate group after 5.5 weeks, in the non-haemodialysate group after 8.3 weeks. There has been a significant difference in the time of rehabilitation between the shank and the thigh muscles. The results show a high statistic significance.

Adult↗
PubMed1989

Congenital ciliary aplasia in two siblings. A primitive disregulation of ciliogenesis?

Congenital ciliary aplasia was demonstrated in two siblings with clinical history of primary ciliary dyskinesia. Ultrastructural histochemistry of successive bronchial biopsies revealed the predominance of immature mucous cells and the total absence of ciliated or preciliated cells in the respiratory epithelium. This original disorder may represent a unique variant of primary ciliary dyskinesia with primitive disregulation of ciliogenesis.

Biopsy↗
PubMed1989

Effect of long-term administration of platelet-activating factor on pulmonary responsiveness and morphology in the guinea pig.

To further substantiate the possible role of platelet-activating factor (PAF) in the development of bronchial hyperreactivity, Alzet osmotic minipumps loaded with the autacoid or solvent alone were placed under the back skin of male Hartley guinea pigs and connected to the jugular vein for 15 days. As compared to the animals treated with solvent alone, guinea pigs receiving PAF (20 micrograms/kg/h, 15 days) exhibited a hyperresponsiveness to histamine that was not observed in those simultaneously treated with PAF and the PAF antagonist BN 52021. Lungs from PAF-treated animals were congestive in appearance, bronchi and bronchioli were contracted, Reisseisen muscles were markedly hypertrophied, and a muciparous metaplasia of the endothelium was observed. The number of eosinophils was significantly increased in the parenchyma, as was the number of mast cells in the peribronchial zones in the lungs from guinea pigs chronically treated with PAF. Lungs from control animals did not show morphologic alterations or eosinophil and mast cell infiltration. These data indicate that long-term treatment with PAF induces profound alterations in the respiratory system, resembling those observed in asthmatic patients. This result is in keeping with the possible role of this autacoid in the development of bronchial hyperreactivity.

Animals↗
PubMed1989

Benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children.

The authors review 42 consecutive cases of benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children undergoing surgery in the pediatric service of the Hôpital des Enfants Malades between 1975 and 1987. Epilepsy was the presenting sign in 76% of the children and remained the only clinical sign at diagnosis in 62%. Partial or complex partial seizures were observed in half of the cases, but other seizure types were also frequent. Diagnosis of the tumor as the etiological agent rested upon the results of computerized tomography or magnetic resonance imaging. Postoperative mortality (5%) and morbidity (16%) rates were low. The postoperative intelligence quotient was above 80 in 71% of the patients, and 77% of the children had no major problem in school. Although only two of the 42 patients were given postoperative radiotherapy, there were no recurrences in 82% of the survivors. The actuarial probability of nonrecurrence of the tumor was 95% at 5 years. Three patients with recurrent tumor underwent further surgery and are, at the present time, recurrence-free. The incidence of epilepsy fell from 76% before surgery to 19% after removal of the tumor alone; therefore, intraoperative electrocorticography and resection of the electrically abnormal cortex at the time of the first surgical procedure do not appear necessary. It is possible that tumor removal restores a mechanism that limits the spread of seizures and, thus, the clinical manifestations of epilepsy. Benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children should not be treated with adjuvant radiotherapy, at least initially.

Adolescent↗
PubMed1989

[Histologic classification and prevalence of tumors of the central nervous system in infants. Study of 100 excision samples].

In order to assess the epidemiological and histological distributions of brain tumors in infants under 2 years of age, 100 cases collected in the Neurosurgery Department of Hôpital Necker-Enfants Malades in Paris during an 11 year period, were reviewed. Histopathological diagnoses were analyzed with special reference to age at the time of diagnosis, sex, topography and grading. Brain tumors were classified into 2 groups: under one year of age, and between 1 and 2 years of age. Certain neoplasms were reclassified after review of the slides. The male-to-female ratio was 1.09:1 for the first group, and 1.25:1 for the second one. In the group of tumors diagnosed under 1 year of age, 60% were supratentorial, and 40% were infratentorial. The percentages reversed after 1 year of age in favor of those of the posterior fossa. The histopathological distribution of these tumors was assessed in the two groups according to Rorke's classification. The three most common histological types were astrocytoma (27% under 1 year versus 36% after 1 year), ependymoma (25% versus 16%) and medulloblastoma (14% in each group). There was a significantly higher prevalence of some types of tumors in the first year of life as compared with those diagnosed after one year.: ependymomas (25% versus 16%), primitive neuroectodermal tumors (PNET) other than medulloblastomas (9% versus 3.5%), choroid plexus tumors (9% versus 17%), and teratomas (5% versus 1.7%). Craniopharyngiomas (2%) and non-tumoral lesions (vascular malformations) (7%) had similar distributions in both groups. There was a preponderance of malignant tumors in the first year of life. Our study demonstrates that brain tumors diagnosed during the first year of life have characteristic and specific features in terms of topography, histopathological distribution and grading.

Brain Neoplasms↗
PubMed1988

Nasal eosinophilia in children: its use in the nasal allergen provocation test.

This pediatric cytological and clinical study aimed at assessing the value of nasal eosinophilia during nasal provocation tests for identifying an offending allergen. The population studied comprised 50 children aged from 4 to 18 yr; 39 of these had well-characterized allergic rhinitis, which in 21 cases was combined with asthma, and the remaining 11 had nonatopic chronic rhinitis. Nasal secretions, collected by nose blowing, were stained with May-Grünwald-Giemsa or Wright stain. The percentage of nasal eosinophils was obtained by examining the cells in the whole slides. Counts were carried out on secretions collected before challenge, after insufflation of saline solution (for verification), and 40 min after insufflation into each nostril of an allergen (housedust mite extract). The nasal provocation test was considered positive when insufflation of the allergen increased nasal eosinophilia by more than 10%, provided that the prechallenge proportion of eosinophils was less than 50%. No increase in specific bronchial resistance was noted. These results indicate that nasal provocation tests are safe, even in asthmatic children.

Adolescent↗
PubMed1988

Eosinophil recruitment into guinea pig lungs after PAF-acether and allergen administration. Modulation by prostacyclin, platelet depletion, and selective antagonists.

Intravenous administration of PAF-acether to the guinea pig induces bronchoconstriction, hypotension, intravascular platelet aggregation, endothelial disruption, and platelet and neutrophil diapedesis. These effects are followed within 1 h by an eosinophilic infiltration into the bronchial walls, which was also noted after the administration of antigen to passively sensitized guinea pigs. Bronchoconstriction and eosinophil infiltration are 2 major features of asthma, and selective bronchial eosinophilia characterizes late asthmatic reactions. We compared the histologic effects of PAF-acether 6 and 24 h after its intravenous injection with those of experimental passive anaphylactic shock, which is used as a model for asthma. Six hours after PAF-acether or antigen (ovalbumin) administration, a marked lung eosinophil infiltration, particularly in the bronchial walls, was noted, together with mucous plugs containing eosinophils in the bronchial lumen. Epithelial desquamation was followed after 24 h by mucous metaplasia of the bronchial epithelium. These effects were not observed when the inactive metabolite lyso-PAF was used. Our results agree fully with the suggestion that the eosinophil mediates the pathophysiology of bronchial asthma and releases materials toxic for the respiratory epithelium. Two PAF-acether antagonists (BN 52021 and WEB 2086) prevented the eosinophil infiltration triggered by PAF-acether and by antigen. When PAF-acether or ovalbumin were injected into guinea pigs after antiplatelet serum or prostacyclin, the eosinophil infiltration was significantly reduced, suggesting that platelets or another adenylate cyclase-sensitive cell are important for the subsequent PAF-acether-induced eosinophil infiltration. Our results support an essential role for PAF-acether in an experimental model of allergic asthma.

Allergens↗
PubMed1988

[Effect of long-term administration of platelet activating factor on pulmonary response and morphology in the guinea pig].

The possible role of PAF in the development of bronchial hyperreactivity was investigated using Alzet osmotic minipumps loaded with PAF or solvent alone and implanted in male Hartley guinea-pigs. Compared to animals treated with solvent alone, those receiving PAF (20 micrograms/kg/h for 15 days) exhibited a hyperreactivity to histamine. The lungs from PAF-treated were congestive in appearance, bronchi and the bronchioli were contracted, Reisseissen muscles were markedly hypertrophied and a muciparous metaplasia of the epithelium was observed. In addition, the number of eosinophils was significantly increased in the parenchyma, as was the number of mast cells in the peribronchial regions. These data indicate that long term-treatment with PAF induces profound alterations in the respiratory system resembling those observed in asthmatic patients. They also strengthen the also strengthen the role of PAF in the development of bronchial hyperreactivity.

Animals↗
PubMed1988

[Circadian variations in the incorporation of gamma-aminobutyric acid (GABA) and tritiated taurine into the pineal body of CD mice].

Pineal uptake of two putative neurotransmitters, gamma-aminobutyric acid (GABA) and taurine, was investigated during the 24 h-cycle in mice kept in long (14L/10D) or short (10L/14D) photoperiods. Tritiated mediators were intraperitoneally injected and their concentration both in pineal gland and cerebellum were measured at several times along the nycthemere. A circadian rhythm of exogenous GABA uptake was observed in mice kept in long photoperiods: GABA uptake was high during the night, when the gland was active and low during the day. It corresponded to the pineal cycle of indoleamine synthesis. It was particularly sensitive to sudden changes of lighting. In short photoperiods, a similar cycle was observed but the result was not significant because of individual variations. Taurine uptake did not show such a circadian rhythm either in long or in short photoperiods: it was constant and rather low with large variations from one animal to another.

Animals↗
PubMed1987

Left ventricular ultrastructure in pulmonary stenosis and in tetralogy of Fallot.

Twelve patients underwent haemodynamic studies and myocardial biopsies: 7 with pulmonary stenosis (PS) and 5 with tetralogy of Fallot (TOF). Their ages ranged between 2 and 43 years. Right ventricular pressure was 128 +/- 43 mmHg in PS and 98 +/- 8 mmHg in TOF. Aortic blood oxygen saturation was 97.0% +/- 1.4% in PS, and 88.4% +/- 6.3% in TOF. Left ventricular (LV) weight was normal in TOF while it was increased in PS: 140.7 +/- 74.3 vs 74.0 +/- 8.7 g/m2 (P less than 0.001). Contractility was altered in both PS and TOF: ejection fractions were 56% +/- 7% vs 65% +/- 6% (P less than 0.001). Light microscopy showed abnormal transverse diameter of left ventricular myocytes in both PS and TOF: 18.6 micron +/- 4.0 micron vs 19.4 micron +/- 4.9 micron. The percentage of interstitium was normal: 29.6% +/- 3.9% vs 26.2 +/- 5.1%. Transmission electron microscopic examination revealed hypertrophic changes in all patients and degeneration in 7 of them. Hyperfunctional alterations of the myocytes were characterized by the increased number and reduced size of mitochondria, the enlarged Golgi complex, the increased number of ribosomes, the marked folding and convolutions of the nuclear membrane, the dilatation and tortuosity of T tubules. Myofibrillar lysis was the major degenerative change, which was also observed in the right ventricle (RV) of the same patients. No correlation was observed between these alterations and the patient ages, RV pressures, aortic blood oxygen saturations and ejection fractions. These findings led us to conclude that: (1) suprasystemic pressure overload of the RV induces macroscopic LV hypertrophy; (2) mild and suprasystemic pressure overload of the RV induces hyperfunctional changes in the LV; (3) myocardial degeneration is not related to hypertrophy nor to hypoxia, but is part of a more widespread cardiovascular fetopathy.

Adolescent↗
PubMed1987

[Experimental and clinical results of ultrasound imaging in sports orthopedic soft tissue diseases].

Ultrasound scanning of the shoulders, knee joints, Achilles' tendon and muscles is presented as a noninvasive technique for the diagnosis of joint and soft tissue disorders. In experimental ultrasound studies on shoulders, knee joints, tendons and muscles of cadavers the diagnostic value of the method is assessed. The experimental observations were compared with clinical results collected in three years from 610 patients. Particularly characteristic findings in sports-induced soft tissue lesions are reviewed as examples.

Achilles Tendon↗
PubMed1987

Interactions between granulocytes and platelets with the guinea-pig lung in passive anaphylactic shock. Correlations with PAF-acether-induced lesion.

To compare the bronchopulmonary effects of anaphylactic shock with those of platelet-activating factor (PAF-acether), antigen (ovalbumin) was administered intravenously to passively sensitized guinea-pig. Subsequent lung alterations were assessed histologically. Within 1 min following ovalbumin, bronchial and arterial constrictions were observed, accompanied by platelet thrombi in the pulmonary microcirculation, intravascular leucocyte accumulation with diapedesis, disruption of endothelium and alterations of type II pneumocytes. Free eosinophilic granules were scattered in the bronchial submucosa. One h after the infusion of ovalbumin, platelet aggregates had disappeared, bronchoconstriction was over, and denudation of the bronchial epithelium was observed. These alterations resemble to those induced by intravenous PAF-acether, which led us to compare the effects of inhaled PAF-acether and antigen at bronchoconstrictor concentrations. In both cases, leucocytes were aggregated in the microcirculation within 2 min and persisted 1 h later. Massive infiltration of eosinophils and activation and clumping of alveolar macrophages were also noted. Our findings support the involvement of PAF-acether in acute anaphylaxis in the guinea-pig.

Anaphylaxis↗
PubMed1987

[Demonstration of Langerhans cells in the human bronchial epithelium].

Ultrastructural and immunohistochemical analysis of six specimens revealed for the first time a small number of Langerhans cells in non-neoplastic bronchial epithelium. These cells were usually found either interspersed perpendicularly between columnar epithelial cells or just above the basal lamina with extending cytoplasmic processes. Usually few Birbeck granules, especially located in the Golgi region, were present throughout the cytoplasm. Immunohistochemical studies were performed on semi-thin sections with a polyclonal anti-S-100 protein. The population of S-100 positive cells represented about 1% of all the epithelial cells. Not all ultrastructurally identified Langerhans cells were shown to be positive for S-100 antigen. Our results suggest that Langerhans cells could be a constant cellular constituent for the normal bronchial epithelium. The exact function of Langerhans cells in the respiratory epithelium remains to be investigated, but they may have an immunologic function, such as antigen presentation to T lymphocytes.

Bronchi↗
PubMed1987

[Solid cold thyroid nodule. Current data].

Attitudes adopted when confronted with a solid cold thyroid nodule are analyzed in the light of recent developments in paraclinical data represented essentially by results of immunological, ultrasound and fine needle cytopuncture examinations. The use of these new surveillance technics frequently allows surgery to be deferred, while if on the contrary operation is decided then it usually now involves both thyroid lobes to avoid nodular recurrence and repeat surgery. Postoperative follow up surveillance is essential to ensure individual adaptation of attitude: therapeutic abstention, suppressive or possibly compensatory treatment.

Biopsy, Needle↗