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Biomedical subjects

I Gil

Publications and source records attributed to I Gil.

At least 55 records · Page 3Linked to original sources

Immunomodifying activity of some amphiphilic compounds from pathogenic Pseudomonas aeruginosa strains.

Molecules of polysaccharide, lipopolysaccharide, and peptidoglycane from Pseudomonas aeruginosa were assayed as immunogens and immunomodifiers. The kinetics of humoral responses, phagocytic activity, splenic index variations, and immunomodulating ability of these molecules were studied. Their protective and immunomodifying effects were compared to those similarly produced by heat-killed bacteria suspensions. The influence of the nature and doses of these molecules as well as the intervals between their administration and the SRBC immunization were also studied. Results showed that higher IgM and IgG levels were produced by lower doses of lipopolysaccharide and peptidoglycane, respectively. Using these amphiphilic molecules at doses of 160 micrograms/mouse, a variable immunodepressive activity was observed. This dose-dependent effect which particularly altered the IgM synthesis, was also observed in phagocytic responses. The exopolysaccharide showed to be the most immunodepressive molecule, and this activity appeared to be dependent of dose and time of administration.

Animals↗

[Proliferative response of murine lymphocytes caused by the activity of amphiphilic molecules from Propionibacterium acnes].

Splenic lymphocytes from mice treated with Propionibacterium acnes cells as well as with their cell walls were found to be variably active on the lymphoproliferative responsiveness. Furthermore, the effect of these bacterial agents on the ex vivo Con A response of the lymphocytes showed a certain stimulation that was higher with oral treatments. In the same conditions the influence of these agents on the LPS lymphocytes stimulation was almost without any statistical significance. In vitro blastogenesis experiments were undertaken in order to elucidate the influence of different amphiphilic molecules from peripheric bacterial structures on the lymphoproliferative response of murine splenocytes. Stimulation rates were also determined as a function of the (3H) thymidine incorporation. Combined effects of mitogens (Con A and LPS) with bacterial amphiphilic molecules were also evaluated as a function of the DNA synthesis variations. All cases resulted in a variable inhibition of the mitogenic response which appeared dose-dependent and more active for associations of Con A and amphiphilic molecules. The most effective intrinsic mitogenic activities were detected with teichoic acids and intracellular polysaccharides. These last molecules without purification, assayed as cytoplasmic fractions, appeared modified in the intensity of their action, depending on their carbohydrate/protein ratios.

Animals↗

Septicemia due to Corynebacterium haemolyticum.

A 65-year-old man in generally good health presented with symptoms of sepsis and mental confusion. Corynebacterium haemolyticum was isolated from three blood cultures, and a significant increase in the titer of immunofluorescent antibodies to the infecting organism was observed. Antigen of C. haemolyticum was demonstrated by double immunodiffusion in samples of cerebrospinal fluid and urine. The patient recovered after i.v. administration of 20 Mu/day penicillin. This is, to the best of our knowledge, the third reported human infection with C. haemolyticum with involvement of the central nervous system.

Aged↗

Growth of Propionibacterium acnes strains on semisynthetic medium; antigenic polysaccharide production.

A semisynthetic medium, containing yeast extract as the only non defined component and glucose, glycerol, Tween 80 and mineral salts, has been developed to grow the strains of Propionibacterium acnes Beck 2037, Gerrath 2038 and Vogel 2039, at a rate comparable to that of complex media. An average of 10(12) cells per 1 (equivalent to approximately 1.5 g/l dry weight) was usually achieved. These yields are appropriated for biochemical and immunological studies, e.g. cell wall preparation, polysaccharides isolation, etc. In this work, some properties of the cell walls (sugar and amino acid composition) and the antigenic polysaccharides (neutral and amino sugar components) are described.

Amino Acids↗

Diagnostic value of distended urinary bladder pyelography in adults.

Intravenous pyelography carried out with a previously distended bladder in order to produce partial urinary flow obstruction offers superior delineation of the pelvi-caliceal system and ureters. Often, these structures are visible in their entirety on a single film. In 100 adult patients of both sexes who had undergone conventional i.v. pyelography, a second examination was carried out without external compression, after preliminary distension of the urinary bladder (DUB). DUB was achieved by three different methods. In 25 patients the urinary bladder was distended by retrograde instillation of saline. Another 25 patients retained their overnight urine and 50 others retained their urine following a water load of 1,000 ml. Best results were obtained in patients examined by the retrograde and water-load methods. The vast majority of examinations in these groups were of superior quality compared with that obtained by the routine technique. Pyelography with a distended bladder proved to be a valuable diagnostic adjunct in all instances in which application of external compression is undesirable, particularly in cases of trauma.

Adolescent↗

Radionuclide cystography: the significance of retention time of the refluxed radioisotope.

We studied 36 patients with vesicoureteral reflux into 45 renal units by means of isotope cystography and a dynamic renal function scan performed 24 to 48 hours after the cystography. Functional impairment was found in 21 renal units. To evaluate the significance of the time between voiding and complete disappearance of the radioisotope that refluxed from the kidney (retention time) the presence of the labeled particles in the kidney was followed continuously and intermittently during a prolonged interval. There was a significant difference between the retention time found in the impaired kidneys and that in the normally functioning kidneys. In 91.7 per cent of the normally functioning kidneys retention time was less than 5 minutes, whereas in 86 per cent of the impaired kidneys it was more than 10 minutes and in 56 per cent it was more than 20 minutes. No significant correlation was found between the retention time and intrarenal reflux or dilatation of the collecting system (patients classified as having radiological grades III and IV reflux were not included in this study). A retention time greater than 10 minutes may be correlated with decreased renal function. The retention of technetium sulfur colloid particles may be analogous to the retention of similar size bacteria and suggests a possible pathophysiologic explanation for the development of renal dysfunction owing to the prolonged presence of bacteria in the kidney after reflux.

Adolescent↗

Right myocardial infarction with predominant right ventricular dysfunction.

Two patients with right ventricular myocardial infarction are described. In both cases, the hemodynamic criteria established for this diagnosis were fulfilled, namely, right-side pressure values (central venous pressure and right atrial pressure) equal to or higher than left-side pressure values (pulmonary capillary wedge pressure and left ventricular end-diastolic pressure). ECG tracings showed acute diaphragmatic myocardial infarction. The lungs were clear both clinically and radiologically. The diagnosis of right ventricular myocardial infarction was confirmed in the first patient by hemodynamic studies and at autopsy, and in the second patient, by hemodynamic and echocardiographic studies. Only in the second care was the administration of massive quantities of fluids and dopamine followed by good results. The importance of establishing a precise diagnosis of right ventricular myocardial infarction is emphasized, since therapy for this condition is different than that for left ventricular myocardial infarction.

Aged↗

Antibiotic production by defective cytoplasmic membrane mutants of Bacillus subtilis.

Eleven defective cytoplasmic membrane mutants of Bacillus subtilis were isolated. Their respective protoplasts presented different lytic behaviour when exposed to decreased concentrations of sucrose. Some relationship was found between the fragility of the protoplasts and the capacity of the mutants to produce antibiotic or to sporulate. The higher the fragility the lesser the capacity to produce antibiotic. The same applies to their amino acids requirements.

Amino Acids↗