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Biomedical subjects

C Pastor

Publications and source records attributed to C Pastor.

90 records · Page 5Linked to original sources
PubMed1986

Prophylaxis of postoperative infections after open-heart surgery by administration of human pepsinated immunoglobulin.

The present controlled study examines the effect of intravenously administered human pepsinated immunoglobulin G (HPIG, Gamma-Venin) on the postoperative incidence of infections in patients undergoing heart surgery supported by extracorporeal circulation. This particular form of surgery normally produces markedly diminished serum IgG levels, but the results of the study showed that these recovered more rapidly after treatment with HPIG. A statistically significant difference in the number of infections between the group treated with HPIG and the control group (p less than 0.05) was found. It may be concluded that, with regard to postoperative infection, patients undergoing open-heart surgery may benefit from the administration of HPIG.

Adolescent↗
PubMed1985

Quantification of choline and ethanolamine phospholipids in rabbit myocardium.

To facilitate evaluation of the influence of myocardial phospholipid metabolites on the development of electrophysiologic abnormalities induced by ischemia, a method for the quantification of choline and ethanolamine phospholipids suitable for accurate and reproducible analysis of small amounts of myocardium was developed. The procedure combines chloroform and methanol extraction of phospholipids after tissue homogenization with subsequent separation by sequential thin-layer and high-performance liquid chromatography. Phosphorus in purified lipid classes was determined with the correction for recovery based on 14C-labeled internal standards.

Animals↗
PubMed1984

[Immunologic responses following surgical resection of gastrointestinal carcinomas].

The amount of IgG, IgM, IgA, C3, C4 and C5 in serum, and the response to delayed hypersensitivity tests with PPD, varidase, candidin and mumps antigens were estimated in patients submitted to radical surgery for gastric and colorectal cancer (group I), before and at intervals after the operation was performed, and compared with cancer patients undergoing palliative abdominal surgery (group II), and with patients submitted to major abdominal surgery for diseases other than cancer (group III). Group I showed a decrease of all the immunoglobulins (Igs) and complement fractions (F) during the first week after operation, and a significant increase after one month. Similar changes were observed in group III, the augmentation of Igs and F after one month being somewhat smaller. Group II showed a larger number of positiveness than either group I or II in both the preoperative and early postoperative periods (p = 0.001). After 2 and 3 months, the number of positive cases was larger in group I than in group II (p = 0.05). According to these results, the immune response is recovered one month after the excision of gastric and colorectal malignant tumors, being this the best moment to receive a complementary cytoreductive therapy.

Complement C3↗
PubMedDate not supplied

The covalent interaction of C3 with IgG immune complexes.

Antigens (Ags) are converted into immune complexes (antigen-antibody complexes, IC) as soon as they encounter their specific antibodies (Abs). In fluids containing complement, the process of IC formation and fixation of complement components occur simultaneously. Hence, the formation of Ag-Ab-complement complexes is the normal way of eliminating Ags from a host. C3b-C3b-IgG covalent complexes are immediately formed on interaction of serum C3 with IgG-IC. These C3b-C3b dimers constitute the core for the assembly of C3/C5-convertase on the IC, which are subsequently converted into iC3b-iC3b-IgG by the complement regulators. These complexes are detected on SDS-PAGE by two bands of molecular composition, C3alpha65-C3alpha43 (band A) and C3alpha65-heavy chain of the Ab (band B), which correspond to C3b-C3b and C3b-IgG covalent interaction respectively, and that identify opsonized IC (C3b-IC). C3b can attach to Fab and Fc regions of the Ab molecule with similar efficiency. The presence of multiple C3b binding regions on IgG is considered an advantageous characteristic that facilitates the elimination of Ags in the form of C3b(n)-IC. Ab molecules on the IC recognize the Ag, and also serve as a very good acceptor for C3b binding. In this way, Ags, even if they have no acceptor sites for C3b, can be efficiently processed and removed. When C3 is activated in serum by IC or other activators, secondary C3b-IgG covalent complexes are generated, with bystander monomeric circulating IgG, and thus constitute, physiological products of complement activation. These complexes gain importance when IgG concentration is extremely high as in cases of infusion of intravenous IgG (IVIG) in several pathologies. The covalent attachment of activated complement C3 (C3b, iC3b, C3 d,g) to Ags or IC links innate and adaptative immunity by targeting Ags to different cells of the immune system (follicular dendritic cells, phagocytes, B cells). Hence C3b marks Ags definitively, from the earliest contact with the innate immune system until their complete elimination from the host.

Amino Acid Sequence↗
PubMedDate not supplied

Continuous pleural infusion of bupivacaine offers better postoperative pain relief than does bolus administration.

BACKGROUND AND OBJECTIVES: To determine whether continuous pleural analgesia offers better postoperative pain relief than does bolus administration in postcholecystectomy patients. METHODS: Eighty postcholecystectomy patients with a subcostal incision were randomly allocated to receive pleural analgesia with either a bolus regime of 20 ml 0.375% bupivacaine with 1:200,000 epinephrine at four-hour intervals (bolus group), or a loading dose of 20 ml 0.375% bupivacaine with 1:200,000 epinephrine immediately followed by a continuous infusion at a rate of 6 ml/hour during the first 24 hours postoperatively (infusion group). A 10-cm linear visual analog scale was used and recorded before performing pleural analgesia and at 1,6,12,18, and 24 hours subsequently. Plasma levels of bupivacaine were determined in eight patients of the infusion group. Samples were taken at 5,15,30, and 60 minutes and at 6 and 18 hours after the start of infusion. RESULTS: Mean visual analog scale values were significantly lower (p less than 0.001) at 6, 12, 18, and 24 hours in the infusion group. PaCO2 decreased significantly (p less than 0.001) after the block in both groups, with no difference between the groups. Plasma levels were well below toxic levels in the infusion group. CONCLUSIONS: Continuous pleural analgesia offers better postoperative pain relief than does bolus administration. Pneumothorax was observed in two patients during the study.

Adult↗
PubMedDate not supplied

[In vitro stability of amikacin and ciprofloxacin administered through a Y-shaped catheter connection with 2 total parenteral nutrition formulations with different pH].

We studied the stability of amikacin and ciprofloxacin in in vitro coinfusion with two total parenteral nutrition. The antibiotic concentrations were determined by EMIT and HPLC for amikacin and ciprofloxacin, respectively. There were not significant differences between theoretical and measured concentrations. The emulsion stability were analyzed by visual inspection, Coulter-Counter and optic microscopy. The emulsion was stable and we didn't find any particle of size greater than 6 microns.

Amikacin↗
PubMedDate not supplied

[Stability of a lipid emulsion in formulations for total parenteral nutrition].

The complex nature of "all in one" formulas for TPN, makes it difficult to ensure the stability of the lipid emulsions in these preparations. Despite the fact that studies on this issue are increasing, official guidelines on maximum acceptable particle size and the methods to control it are still lacking. The objective of this study was to assess the stability of a lipid emulsion in four standard mixtures also containing amino acids, glucose or F-G-X, electrolytes and vitamins or trace elements. Lipid stability was assessed visually through electronic counts and microphotographs. The pH of mixtures ranges between 5.3 and 5.9, not changing with time nor storage temperature. Visual observation showed a possible rupture of the emulsion in one mixture after storing 96 hours at room temperature, but not when stored at 4 degrees C. Mean diameter of fat particles did not change. The percentage of droplets having a diameters under 1.2 micron was higher than 90%, although particles greater than 6 micron appeared in all mixtures. Micrographic observation revealed the presence of aggregates with a diameter greater than 8 microns in one mixture. According to the results obtained, one of the mixtures may be considered physically unstable. The clinical viability of this mixture and of the other three stable mixtures, depends on the limits considered acceptable regarding particle size. Due to the slight composition differences of the mixtures studied, it is difficult to explain the difference in behavior observed. Therefore, it would be adviceable to study standard "all in one" mixtures of known stability, while waiting for more conclusive studies to be performed, especially in the case of critical mixtures.

Drug Stability↗