Biomedical subjects
Publications and source records attributed to A Pfister.
The authors report an observation of acute myocarditis characterized by an interstitial inflammatory cell infiltrate associated with patchy acute cell damage. Two consecutive endomyocardial biopsies have been performed which allowed to correlate myocardial alteration with ventricular hemodynamic modifications.
The present report concerns a 10-year-old boy in whom diabetes insipidus and short stature were the first manifestations of a suprasellar germinoma. Neuroradiological investigations performed when these symptoms appeared were negative. 2 years later, a rapid and early pubertal development was observed and related to secretion by the germinoma of human chorionic gonadotropin (hCG) identified immunohistochemically. This clinical evolution is unusual and indicates that plasma hCG measurements in patients with so-called idiopathic diabetes insipidus can be of clinical value in predicting the presence of an hCG-secreting tumor.
This study reports the nuclear alterations during ventricular hypertrophy of human heart. The nuclear length is increased while its diameter remains normal. A large spectrum of morphological alterations was observed: increased foldings and convolutions of the membrane; irregular shape of the nuclei, some of them being dumbbell-shaped; intranuclear pseudo-inclusions; intranuclear tubules. These alterations are related to excessive synthesis of membrane during nuclear growth.
The distribution of skin calcium-binding protein in squamous cell metaplasia of human endocervix, in normal human skin, and in ovarian cancer was determined by the immunofluorescence technique. A rabbit antiserum specific to rat SCaBP was characterized by Ouchterlony immunodiffusion and by immunoprecipitation of 125I-labeled SCaBP. The specificity of antibody labeling was demonstrated by using preimmune rabbit serum and SCaBP antiserum competitively absorbed with purified SCaBP. In normal human skin SCaBP was found exclusively in the basal layer cell cytoplasm. This protein was not detected in normal columnar epithelium of endocervix. Epithelial tissues in the zone of transition between the cylindrical epithelium of the endocervical mucosa and the stratified squamous epithelium of the exocervix were obtained from 14 patients with a wide variety of squamous cell metaplasia. In the early stage of metaplasia SCaBP was detected exclusively in the cytoplasm of reserve undifferentiated cells. In the terminal stage of metaplasia the SCaBP was present only in the basal cell layer. SCaBP was found in several layers of dysplastic tissue, and this distribution appeared to be related to the loss of normal maturation of the epithelium. SCaBP was also present in squamous cell carcinoma of endocervix especially in the least differentiated regions of the tumor. No SCaBP was detected in any ovarian cancer cells. These findings are potentially useful as a means of early detection of squamous metaplasia and of distinguishing premalignant anaplastic lesions from those that are benign and nonproliferative. In addition, the presence of SCaBP in tumors derived from metaplastic epithelia and its absence in the ovarian cancer indicate that immunohistochemical search for this protein might be of value in tumors in which an epidermoid origin is a possibility.
Isolated glomeruli and tubular and medullary cells obtained from perfused kidneys from Wistar rats were stimulated with ionophore A 23187 (0.5 to 6 microM) or kept overnight at pH 9.5. The amount of platelet-activating factor (Paf-acether) formed was measured in the ethanolic cell extracts using aggregation of washed rabbit platelets. 2-Lyso Paf-acether present in cells was transformed into Paf-acether by chemical acetylation and measured in the same manner as Paf-acether. Microsomes from glomeruli and medullary and tubular cells were prepared, and the acetyltransferase activity was measured. Paf-acether was formed in a dose-dependent fashion by glomeruli and medullary cells, and maximal formation with 3 microM ionophore A 23187 was 1.9 +/- 0.2 and 1.1 +/- 0.2 pmoles/mg of protein, respectively. Paf-acether was not recovered from tubular cells. Three cell types produced large amounts of 2-lyso Paf-acether when incubated at alkaline pH. Only glomeruli generated appreciable quantity of 2-lyso Paf-acether upon ionophore A 23187 stimulation. The acetyltransferase specific activities in ionophore A 23187-stimulated glomeruli and medullary and tubular cells were 3.8 +/- 0.8, 0.3 +/- 0.1, and 0.2 +/- 0.1 nmoles of Paf-acether/10 min/mg of protein, respectively. This study demonstrates the formation of Paf-acether by two distinct populations of kidney cells, pointing out the glomerular cells, besides the already known medullary cells, as capable of forming Paf-acether.
The ability of Paf-acether to induce increased plasma protein extravasation (IPPE) was assessed in the skin of rats by measuring extravasation of 125I-bovine serum albumin. Paf-acether elicited dose-dependent IPPE with a threshold of 0.04 pmol and a maximum at 4.5 nmol, with an effective concentration (EC50) of 23 pmol. The EC50 of the 1-0-ester Paf-acether analog was 1.5 nmol whereas 2-lyso Paf-acether was ineffective in inducing IPPE. Serotonin and histamine were respectively 100 and 1,00-fold less potent than Paf-acether. High doses of Paf-acether also resulted in a dose related accumulation of III-indium oxine labeled platelets. Ultrastructural and radioisotopic studies showed that Paf-acether-induced IPPE was not dependent upon platelet accumulation. In addition, platelet release products were ruled out in this phenomenon, since a "cocktail" of indomethacin, methysergide and pyrilamine-maleate failed to significantly reduce Paf-acether-induced IPPE. Neutrophils were not involved in Paf-acether -induced IPPE since nitrogen mustard-treated animals presented with IPPE not significantly different from controls. Finally, the specificity of Paf-acether on IPPE formation was demonstrated by its complete prevention by prior intravenous injection of Paf-acether (6 ug/kg), but not of Paf-acether analogs, histamine or serotonin.
The authors report 47 cases of intracranial ependymomas occurring in children less than 15 years of age, who were operated on from 1969 to 1979. The aim of the study was to study the incidence of intraspinal metastases and to suggest a logical protocol for postoperative radiotherapy. The operative mortality rate was 17%. The 5 year survival rate, after exclusion of postoperative mortality, was 51%. Recurrences developed in 41% of cases and metastases in 20%. Among these, intraspinal metastases occurred in 14.5% and were found only in infratentorial ependymomas, whether benign or malignant. The results and those in the literature suggest that a protocol of irradiation adapted to the site and the histological grading of these tumors should be discussed with the teams of radiotherapy; in infratentorial ependymomas, the irradiation should include the whole craniospinal axis.
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This work outlines the endocrine abnormalities associated with intracranial germinomas (14 patients before treatment). Diabetes insipidus of various intensity was present in all cases. Adipsia is often present as well. In six patients, the first neuroradiologic examination after the onset of DI was normal. Growth hormone secretion was deficient in 11 of 13 patients. Abnormalities of TSH response to TRH were present in nine of ten (four insufficient and five exaggerated responses to TRH). Anterior pituitary dysfunction could not be predicted by the tumor site as determined by radiologic criteria. Tumoral markers have also been studied. Elevated plasma tumoral markers were found in four patients of 11 studied. Tumoral germinoma cells were present in CSF in five patients of ten, in one of them before radiologic confirmation. Pertinent endocrine evaluation and search for tumoral markers was of great value in systematic follow-up of patients with central diabetes insipidus, and could lead to early diagnosis and treatment of the tumor.
Lesions of the talar cartilage are extremely difficult to diagnose clinically or roentgenologically. Often they are masked by accompanying lesions of the bone or the capsular ligaments, so that arthrotomy will be necessary to obtain information on the condition of the cartilage. Reconstruction of the articular surface is a most important prerequisite für restoring the ability of the cartilage to cope with physiological load. Hence, the aim of the treatment is the replantation of abraded cartilaginous fragments. The use of concentrated fibrinogen as a biological tissue adhesive has been gaining in importance as an alternative to the methods of refixation practised so far. The actual process of gluing is technically simple. 7 patients in whom gluing of the cartilage at the talus had been performed, remained free from complaints for a follow-up period of three years.
After horseradish peroxidase was injected into the rat pineal gland, isolated and rare labelled perikarya appeared in the central nervous system, particularly in the habenula, colliculi, amygdala, paraventricular and suprachiasmatic nuclei, preoptic area and olfactive centers. This indicates that the innervation of the pineal gland is not only orthosympathetic but that some stimuli can be directly transmitted from the brain to the pineal stalk.
Besides the l-ascorbic acid (C1 factor), we put in evidence the l-epi-3',4',5',5,7-pentahydroxyflavan-3-ol (C2 factor) in the blood capillary wall. It was mainly located and found in the endothelial cell membranes. To reach that results, we used an original method using a specific polyphenoloxydase extracted from Psaliota campestris.
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Histamine chlorhydrate was intravenously injected to Guinea pigs (7 microgram/kg). Alterations of the alveolar walls capillaries were by electronic microscopy studied 1.5, 12 and 15 minutes after injection. It was observed a rapid dilator effect associated with an opening of the endothelial cells tight junctions, an increasing in the size and turnover of pinocytic vesicles, an enlargement and a loss of homogeneity of the basal membrane and an edema of type I pneumocytes. In the last group of animals, lesions reversibility is characterized by a beginning of closing of endothelial cells junctions and of edema resorption. These morphological findings point out the local effect of histamine on the pulmonary capillary microcirculation and show the decrease of resistance and the increase of permeability of the capillaries.
The part of ascorbic acid in the blood capillary wall is shown by deficiency experiment. The pictures obtained by electron microscopy show that, non only is the ascorbic acid needed for the structure integrity of the basement membrane, but also for the permeability of the capillary wall, which when this compound is lacking becomes too important.
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