Biomedical subjects
Publications and source records attributed to J Simon.
Urinary infection is found in less than 10% of renal stone formers. It is three times more common in women than in men. Urea-splitting bacteria (Proteus, Klebsiella, pyocyaneus, staphylococcus) leading to stone formation are identified in two thirds of the cases. The percentage of the different bacteria varies depending upon the sex and degree of resistance to therapy. The sensitivity of bacteria to eight commonly used drugs was investigated.
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Experimental allergic encephalomyelitis (EAE) was induced in guinea-pigs and rats by sensitization with encephalitogenic antigens and adjuvant. Treatment of the experimental animals by daily intraperitoneal injections with human fibrinopeptides A and B proved to produce significant changes in the course of EAE. In the treated animals as compared to controls the clinical neurological signs of the disease wuch as the number, the severity and the duration of pareses were diminished. Furthermore, the inflammatory alterations of vasopermeability associated with extravasation of plasma proteins and oedema of the neuroparenchyma were significantly less pronounced in the fibrinopeptide-treated animals. Finally, a significantly higher titre of circulating immune complexes was observed in the serum of these animals. However, the treatment with fibrinopeptides A and B did not alter the specific immune response to the antigenic challenge. No differences in anti-basic protein and anti-brain antibody production were observed. The characteristic cellular infiltrates of EAE also showed no significant qualitative or quantitative differences between fibrinopeptide-treated animals and the saline-treated controls. These results suggest that fibrinopeptides A and B act primarily on the immunologically non-specific phase of EAE development by reducing the severity of vascular permeability alterations.
This paper confirms the finding that rheumatoid factor (RF) can cause non-specific fluorescence in fluorescent-antibody tests for toxoplasmosis carried out with IgM antiserum (Remington test). There is a 20 to 25 p. cent risk of such error, depending on the conditions under which the test is read. Elimination of the risk by the subjection of all sera to preliminary absorption, as proposed by Camargo et al., does not seem justified as the proportion of positive Remington tests is very low in France (approximately 1,5 of every 1000 sera tested) and the work involved would be wasted is most cases. What is proposed here is to tackle the problem at the other end by taking every serum with a positive response to the Remington test, testing it for RE, absorbing it on heat-aggregated human globulin of placental origin, and determining its IgM toxoplasma antibody titre again.
More than a thousand bone calcium content measurements were made in a group of children by means of densitometry, using the Norland-Cameron apparatus. The region chosen was that dividing the middle from the lower third of the radius, and the method used ensures that only a very weak dose is delivered to a limited field of the forearm. Errors occur more frequently in children than in adults because of lack of immobility and the large amounts of fatty tissue present. Normal curves were established as a function of age and sex in 405 control children of French nationality. These were similar to those obtained in a group of children from the Cameron but French children appear to have lower mineral levels than American children. This method is reproducible and suitable for surveillance of changes in mineral levels in the same subject.
Bone calcium content was studied in 200 children who had received long-term therapy with anticonvulsants or corticoids, or who presented retarded growth (more particularly, pituitary deficiency treated with somatotropin, thyroid deficiency treated with thyroid extracts, or Turner's syndrome). It was demonstrated that 25 p. cent of children on anticonvulsant therapy, 30 p. cent of those on corticoid treatment, and nearly all those with retarded growth had a mineral content much below normal levels. Bone densitometry by absorption of a monochromatic iodine-125 beam is a rapid, precise method, which is not dangerous at the dose delivered, and appears to be well adapted for surveillance of children with anomalies in calcium content.
We report a 10-year-old boy who has Fanconi's anemia and was admitted because of acute hemiplegia of the left side. Internal carotid arteriography disclosed a moyamoya cerebrovascular pattern on the right side. Although this condition may be acquired, it is suggested that in this case the moyamoya might pertain to the array of congenital malformations associated with Fanconi's anemia. Intracranial accidents occurring in Fanconi's anemia are generally ascribed to the bleeding tendency; however, the possibility of an underlying vascular anomaly should also be considered.
The macrocyclic amine, cyclam, has been found to be an efficient complexing agent for Tc-99m. Complexes can be formed in yields of higher than 95% at pH 11 in 10(-3) M cyclam using 5 x 10(-6) M SnC4H4O6 as a reducing agent. The complex is positively charged and is stable in air. It is not decomposed by dilution, by 0.05 M NaOH, or 0.05 M H2O2, but does show slight decomposition in 0.05 M HCl. In unanesthetized mice the complex is cleared rapidly from the blood by the kidneys and liver. Preliminary studies show that derivatives of cyclam also complex Tc-99m.
Increasing importance is being given to the residual effects of hypnotics on the day following absorption; with zopiclone, a new hypnotic, we have studied vigilance 9, 12 and 15 hours after a single evening dose of 10 mg, on a double-blind basis in comparison with 10 mg of nitrazepam and a placebo. The assessment of vigilance is based on responses to self-rating questionnaires and psychometric tests. Twenty-one healthy subjects forming a homogeneous group as regards age, I.Q., and vigilance were included in this study. Each subject received the three products in random distributed order, with an interval of three months between each trial. The results of these tests reveal modifications which, particularly 9 hours after administration, reflect a modification in vigilance, appearing to be more marked with nitrazepam than with zopiclone. Thus, from the point of view of the residual effects of hypnotics on vigilance, it is possible to position the products tested in the following order: placebo -- zopiclone -- nitrazepam.
The authors describe a technique for injecting the placenta, using an iodine contrast solution which allows a radiographic picture to be obtained. The vascular supply of the placenta can be shown up by this method accurately and cotyledons can be identified so that their number and their surface can be measured. The preliminary results show that there is a significant difference between the placentas of normal infants and of those with growth retardation. This should give rise to a new approach of the syndrome of intra-uterine growth retardation.
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Microembolization from an ulcerated carotid artery to both occipital lobes via a persistent trigeminal artery was observed in a patient presenting with episodic bilateral central scotomata. Symptomatic relief was obtained following carotid endarterectomy. This unique pathway which resulted in occipital lobe ischemia has not been previously reported.
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In chicken thymocytes isolated from 15--40 day-old chickens, after a 2 h incubation at 37 degrees C, insulin stimulated amino isobutyric acid uptake (maximal response: 40--50% of increase at 1 microgram insulin/ml and half maximal response at 60 ng/ml) by specifically stimulating the influx without altering the efflux. Insulin also stimulated glucose oxidation (maximal response: 11% of increase at 1 microgram insulin/ml). Binding of 125I-labelled chicken insulin to thymocytes was rapid and higher at 15 degrees C than at 37 degrees C. At steady state, (90 min at 15 degrees C), chicken, porcine and goose insulins were equipotent in inhibiting the binding of 125I-labelled chicken insulin. Maximal binding capacity was estimated at 1250 pg insulin/10(8) cells, i.e., 1250 binding sites/cell with an apparent dissociation constant of 200 ng insulin/ml at 15 degrees C. Degradation of 125I-labelled chicken insulin in the incubation medium was negligible at 15 degrees C but very noticeable at 37 degrees C. Therefore, the low level of insulin binding at 15 degrees C reflects a true scarcity of insulin receptors in chicken thymocytes as compared to rat thymocytes.
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This paper reports the effect of polyunsaturated phospholipids (Lipostabil, Nattermann, Cologne) on the severity of experimental allergic encephalomyelitis (EAE) in guinea pigs. A dose of 100 mg/kg of Lipostabil solution, containing about 50 mg of unsaturated fatty acids (UFA), was inoculated i.v. beginning on the 3rd day after sensitization with 100 microgram of basic protein (BP) in complete Freund's adjuvant (CFA). A series of 7--14 daily injections either completely inhibited EAE or reduced its severity. The production of anti-BP antibodies, detected by indirect immunofluorescence and radioimmunoassay, was not affected, whereas cellular reaction as measured by a skin test was markedly reduced. These findings confirm previous reports on the immunoregulative effect of UFA, even if a potentiating effect of additional components of Lipostabil (vitamin B6, nicotinic acid and adenosine-5-monophosphoric acid) cannot be excluded. Serological findings support the assumption that the regulative effect mainly influences the cellular response. In this way deviation in the immune reaction leading to cellular immunopathology might be prevented or decreased.
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The effects of training to various rhythms of intermittent total starvation (ITS) or intermittent protein starvation (IPS) on the plasma glucose and the plasma insulin levels were studied in the growing chicken. Both types of feeding improved the glucose tolerance in spite of a decrease in the insulin response. After an oral glucose load, plasma free fatty acids showed opposite variations to plasma insulin and plasma glucose. The insulin released in response to a test meal was unchanged. In the ITS 1-1 group (1 day fasting-1 day feeding cycles), low glycemia-low insulinemia were observed during the fasting period of the cycle and high glycemia-hyperinsulinemia during the repletion period in response to the "adaptive hyperphagia." In the IPS 1-1 group (1 day feeding with the protein free diet-1 day feeding with the balanced diet cycles), glycemia was sustained at a high level during both periods of the cycle and insulinemia was depressed by feeding with the protein-free diet and highly stimulated by refeeding with the balanced diet. Therefore, in the chicken, intermittent feeding increases the insulin sensitivity of target tissues and modifies the B-cell sensitivity to glucose. The highest decrease in B-cell sensitivity to glucose was obtained with the protein free diet which further emphasizes the glucose-amino acid synergism previously observed for insulin release.