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Biomedical subjects

C García

Publications and source records attributed to C García.

At least 73 records · Page 4Linked to original sources
PubMed2000

Development in lipid analysis: some new extraction techniques and in situ transesterification.

The development of methods for analyzing fatty acids that provide rapid and reliable results is currently in great demand. Recently, different lipid extraction procedures such as microwave or supercritical fluid extraction have heen researched. Both procedures avoid the use of large volumes of solvents and provide rapid lipid isolations. Only a few papers have reported work on microwave extraction, hut many studies ahout supercritical fluid extraction have heen carried out and have heen gaining acceptance within the scientific community. Avoiding the lipid isolation step, hy synthesizing fatty acid esters hy simultaneous lipid extraction and derivatization through in situ reactions, has also heen proposed. The saving of time and reagents is significant. Owing to the differences among the procedures, some knowledge of their characteristics is essential in order to improve methods and achieve reliable and accurate results. Clearly, results depend on factors such as the type of catalysis selected, the use of nonpolar solvents, heating applied during the synthesis, and the degree of suitability of the procedure chosen for the particular features of each sample.

Animals↗
PubMed2000

p16(INK4a) gene alterations are frequent in lesions of mycosis fungoides.

Mycosis fungoides is usually an indolent disease that, after a variable period of time in a stable phase, evolves into a tumoral form with aggressive behavior. The molecular events that mark this progression remain essentially unknown to date, and this prompted us to investigate the hypothetical role of p16(INK4a) silencing in mycosis fungoides progression. We analyzed the three most frequent mechanisms of inactivation of the p16(INK4a) gene (deletion, promoter hypermethylation, and mutation) in nine cases with patch/plaque and tumoral lesions of mycosis fungoides. The existence of alterations was investigated by microsatellite analysis, methylation-specific polymerase chain reaction, and direct sequencing. Alterations of the p16(INK4a) gene were found in four of nine of the plaque lesions (hypermethylation in three samples and allelic loss in one sample) and seven of nine in the tumor lesions (hypermethylation in five samples and allelic loss in three samples). No case presented point mutations. Although a higher incidence of p16(INK4a) hypermethylation was observed in the cases that failed to achieve a complete remission, the limited size of our series prompted us to evaluate this finding cautiously. The results of this study therefore showed a common genetic alteration that is found more frequently in tumoral lesions than it is in plaque lesions of mycosis fungoides. It also offers data that could suggest a relationship between p16(INK4a) hypermethylation and unfavorable clinical outcome. Broader studies are needed to confirm both relationships.

Adult↗
PubMed2000

Clinical, physical, sperm and hormonal data in 251 adults operated on for cryptorchidism in childhood.

OBJECTIVE: To determine the clinical, physical, sperm and hormonal status during adulthood in cryptorchid patients operated on during childhood, and to assess these variables according to the age at surgery and preoperative testicular position. PATIENTS AND METHODS: A letter was sent to all 890 patients > 18 years old who underwent surgery for cryptorchidism during childhood; 274 responded and were assessed using a sexual history, physical examination, pituitary axis study and sperm analysis. Data were complete for 251 patients (mean age 21 years, range 18-30); 196 had unilateral (25 anorchic) and 55 had bilateral cryptorchidism. Clinical, surgical and anatomopathological records at surgery during childhood were also reviewed. RESULTS: The mean (SD) age at orchidopexy was 6.4 (3.3) years and the mean age at assessment 21.1 (2.7) years. Semen samples generally showed abnormalities; 10 patients (4%) with bilateral and 57 (23%) with unilateral cryptorchidism had semen values within the normal range. There was no correlation between the sperm count and age at surgery for unilateral or bilateral cases (Spearman test). There was a significant correlation (r = - 0.41) between the sperm count and level of follicle-stimulating hormone (FSH). There were no significant differences in the sperm count for patients with different testicular locations (ANOVA) or in those treated or untreated with human chorionic gonadotrophin (Student's t-test). The only significant relationship (P < 0.001) was between the sperm count and unilateral or bilateral cryptorchidism. CONCLUSIONS: The sperm quality of adults operated on for cryptorchidism during childhood is independent of the age at surgery or testicular location, but is influenced by whether the cryptorchidism was unilateral or bilateral. FSH levels were negatively correlated with sperm density.

Adolescent↗
PubMed2000

Microbial populations and volatile compounds in the 'bone taint' spoilage of dry cured ham.

'Bone taint' is one of the most important causes of spoilage of dry cured ham. This alteration is characterized by a foul-smelling odour. The microbial population and volatile compounds associated with incipient 'bone taint' were evaluated. Enterobacteriaceae species were found at levels of 7.94 x 10(5) cfu g(-1) in spoiled hams and were not detected in unspoiled hams. Serratia sp. and Proteus sp. are the main organisms characterized. The volatile compounds from the spoiled hams give rise to higher levels of ketones, alcohols and esters than unspoiled hams, that could be originated by microbial metabolism of the above bacteria. Thus, volatile and Enterobacteriaceae analyses should be used to determine this incipient spoilage in the meat industry.

Alcohols↗
PubMed2000

Subchronic toxicity of the new quinolone antibacterial agent irloxacin in beagle dogs.

The subchronic oral toxicity of the new quinolone antibacterial agent irloxacin (6-fluorine-7-(pyrrol-1-yl)-1-ethyl-1,4-dihydro-4-oxo-quinolone- 3-carboxylic acid, CAS 91524-15-1) in Beagle dogs was investigated in studies of 4 and 29 weeks of duration. In both studies animals received dosages of 10, 120 and 1400 mg/kg/d. Pale coloured faeces were seen on animals receiving 1400 mg/kg/d. Animals receiving 1400 mg/kg/d for 29 weeks showed an increased incidence of wax in the ears during the latter half of the treatment period, and one male and one female experienced transitory locomotive difficulties at the end of the first week of treatment. The liver was identified as the target organ for toxicity with presence of lipofuscin in the hepatocytes of animals receiving 120 or 1400 mg/kg/d for 29 weeks. Slight increases in liver weights were observed in animals receiving 120 or 1400 mg/kg/d for 4 weeks, and in all groups receiving irloxacin for 29 weeks. However, no histopathological findings were observed in the liver of animals receiving irloxacin for 4 weeks or those receiving 10 mg/kg/d for 29 weeks. Other relevant findings observed in the 29 week study were increased triglyceride, phospholipid and cholesterol levels in males receiving 120 mg/kg/d and animals receiving 1400 mg/kg/d, increased albumin and decreased beta-globulin concentrations in females receiving 1400 mg/kg/d, and prolonged activated partial thromboplastin time in animals receiving 1400 mg/kg/d. On the basis of the results obtained it is concluded that 10 mg/kg/d can be considered as the non-toxic dose after 29 week oral administration of irloxacin in dogs.

Animals↗
PubMed2000

Energy requirements in Chilean infants.

AIM: To evaluate the energy requirements of breast fed infants. METHODS: The study was conducted in 17 healthy exclusively breast fed infants of normal birth weight (mean (SD) 3332 (280) g). Energy expenditure by the doubly labelled water method and milk intake by the dose to infant method were measured at 34 (4) days. A dose of 0. 2 g/kg deuterium oxide (99.8%) and 2.0 g/kg 10% (18)O labelled water was given to the infants, and urine samples were collected for seven consecutive days after dosing. RESULTS: The mean (SD) weight of the infants during the period of evaluation was 4617 (343) g and weight gain 34.0 (7.5) g/day. Daily milk intake was 728 (101) g and its metabolisable energy content 2.71 kJ/g. The energy expenditure of the infants was 1205 (312) kJ/day and energy required for growth was 607 (130) kJ/day. When combined this produced an energy requirement of 391 kJ/kg/day for these infants. CONCLUSION: These data agree with those from other studies in the United Kingdom and the United States and suggest that adequate growth can be achieved with 19.4% less energy than recommended by FAO/WHO/UNU.

Body Composition↗
PubMed2000

Effect of early versus late administration of human recombinant erythropoietin on transfusion requirements in premature infants: results of a randomized, placebo-controlled, multicenter trial.

OBJECTIVE: The administration of recombinant human erythropoietin (rHuEPO), started after the first 2 weeks of life, reduces the transfusion requirement in premature infants. However, its use throughout the first 2 weeks of life, when anemia results predominantly from phlebotomy losses, remains controversial. We investigated whether early use of rHuEPO would reduce the total transfusion requirement and/or the number of transfusions throughout the first 2 weeks of life. METHODS: We randomized 114 infants with birth weight (BW) <1250 g to receive rHuEPO (1250 units/kg/week; IV; early group: n = 57) or placebo (late group: n = 57) from day 2 to day 14 of life; subsequently, all the patients received rHuEPO (750 units/kg/week, subcutaneously) for 6 additional weeks. All infants were given oral iron (6 mg/kg/day) and folic acid (2 mg/day). RESULTS: The early group showed higher hematocrit and reticulocyte counts than the late group in the first 3 weeks of life, but there was no difference in the total number of transfusions (early: 1.8 +/- 2.3 vs late: 1.8 +/- 2.5 transfusion/patient) or the transfusion requirement throughout the first 2 weeks of life (early:.8 +/- 1.1 vs late:.9 +/- 1.3) could be demonstrated. In infants with BW <800 g and total phlebotomy losses >30 mL/kg (n = 29), a lower number of transfusions was received by infants in the early group, compared with late group, from the second week to the end of the treatment (early: 3.4 +/- 1.1 vs late: 5.4 +/- 3.7 transfusion/patient). No clinical adverse effects were observed. Thrombocytosis was detected during the treatment with rHuEPO in 31% of the infants. CONCLUSIONS: In the whole population, the early administration of rHuEPO induced a rise of reticulocyte counts, but not enough to reduce the transfusion requirement. The most severely ill infants (BW <800 g and phlebotomy losses >30 mL/kg) seemed to benefit from early use of rHuEPO, and this deserves additional study.

Anemia, Neonatal↗
PubMed2000

Pulpal evaluation of two adhesive systems in rat teeth.

Formocresol is the agent most frequently used with pulpotomies in primary teeth, but its use is currently under discussion in regard to its possible toxic effects. Some current works suggest the use of dentinal adhesives in cavities with minimal dentinal thickness and even in small pulpal exposures. Our objective was to evaluate pulpal response to the application of two dentinal adhesives Syntac and Prime & Bond NT in pulpal exposures in rat teeth. Sprague Dawley rats were used, male, 150 to 200 gm in weight. The maxillary first molar, left and right, was employed in each case, a total of twelve teeth. Duration of the study was 45 days. Sections were evaluated using a light microscope in order to determine pulpal response to the two adhesives. In both groups the persistence of chronic inflammation was associated with the absence of dentinal bridges in the affected specimens. Areas of necrosis and absence of regularity of the odontoblastic layer could also be seen.

Animals↗
PubMed2000

Biochemical characterization and inhibitory effects of dinophysistoxin-1, okadaic acid and microcystine 1-r on protein phosphatase 2a purified from the mussel Mytilus chilensis.

Protein phosphatases are involved in many cellular processes. One of the most abundant and best studied members of this class is protein phosphatase type-2A (PP2A). In this study, PP2A was purified from the mussel Mytilus chilensis. Using both SDS-PAGE and size exclusion gel filtration under denaturant conditions, it was confirmed that the PP2A fraction was essentially pure. The isolated enzyme is a heterodimer and the molecular estimated masses of the subunits are 62 and 28 kDa. The isolated PP2A fraction has a notably high p-NPP phosphatase activity, which is inhibited by NaCl. The hydrolytic p-NPP phosphatase activity is independent of the MgCl2 concentration. The time courses of the inhibition of the PP2A activity of p-NPP hydrolysis by increasing concentrations of three phycotoxins that are specific inhibitors of PP2A are shown. Inhibitions caused by Okadaic acid, dinophysistoxin-1 (DTX1, 35-methylokadiac acid) and Microcystine L-R are dose-dependent with inhibition constants (Ki) of 1.68, 0.40 and 0.27 nM respectively. Microcystine L-R, the most potent phycotoxin inhibitor of PP2A isolated from Mytilus chilensis with an IC50 = 0.25 ng/ml, showed the highest specific inhibition effect an the p-NPP hydrolisis. The calculated IC50 for DTX1 and OA was 0.75 ng/ml and 1.8 ng/ml respectively.

Animals↗
PubMed2000

[Abdominal compartmental syndrome in non-injured patients].

Abdominal compartment syndrome (ACS) is characterized by increased intraabdominal pressure and a set of secondary pathophysiological changes in the abdominal. ACS has reappeared in the literature recently in relation to the surgical concept to damage control, applied particularity in contexts of severe abdominal injury polytraumatized patients. We report two cases of ACS that appeared after scheduled abdominal surgery: one after repair of a large eventration and the other in the context of septic shock due to fecaloid peritonitis. Both patients died of multisystem organ failure in spite of surgical decompression. We wish to emphasize that ACS can appear in contexts other than surgery for damage control, and we stress the need to measure intravesical pressure as a reflection of intraabdominal pressure, particularly in certain high risk patients in the postoperative recovery ward. Finally, we review the pathophysiology of ACS and its management, which is based on early treatment to prevent multisystem organ failure with an associated high risk of death.

Abdomen↗
PubMed2000

[Study of macrolide-resistant genes in group C and G streptococci].

In the present study we investigated the macrolide-lincosamide-streptogramin B (MLSB) resistance in 47 clinical isolates of group C beta-hemolytic streptococci and 17 group G streptococci. Resistance to erythromycin was found in 31.6%; and 47%, respectively. On the basis of the erythromycin-clindamycin double-disk test, all strains were assigned to the MLSB phenotype. None of the strains were of the M phenotype. The distribution of the erythromycin-resistant genes were studied by dot blot hybridization and PCR. Resistance to erythromycin was due to the presence of mefA, ermB and ermTR genes. The ermTR gene was predominant among the group C and G streptococci (90% of the strains). Different mechanisms of erythromycin resistance predominate in group C and G streptococci than in Streptococcus pyogenes where there is an association between erythromycin resistance and active-efflux mechanism. Two of the strains harbored more than one erythromycin-resistant gene.

Anti-Bacterial Agents↗
PubMed2000

Bovine monocyte-derived macrophage function in induced copper deficiency.

The effect of molybdenum-induced copper deficiency on monocyte-derived macrophage function was examined. Five female calves were given molybdenum (30 ppm) and sulphate (225 ppm) to induce experimental secondary copper deficiency. Oxidant production by bovine macrophages was measured after stimulation with phorbol myristate acetate (PMA) and opsonized zymosan (OpZ). Lipoperoxidative effects inside of macrophage, superoxide dismutase activity, superoxide anion and hydrogen peroxide formation were determined. Copper deficiency was confirmed from decreased serum copper levels, and animals with values less than 5.9 micromol/l were considered deficient. The content of intracellular copper decreased about 40% in deficient cells compared with the controls. The respiratory burst activity determined by nitroblue tetrazolium reduction was significantly impaired with both stimulants used. Superoxide anion formation was less affected than hydrogen peroxide generation. In addition, increased lipid peroxidation was observed. It could be concluded that the effect of these changes may impair the monocyte-derived macrophage function in the immune system.

Animals↗
PubMed2000

[Medical-surgical experience of intestinal intussusception. Experience of a university institution].

BACKGROUND: Management of intestinal intussusception in children has evolved from exclusively surgical treatments to nonoperative reduction under fluoroscopic monitoring. AIM: To report a 10 year experience in a University Hospital in the management of intestinal intussusception. PATIENTS AND METHODS: Seventy two patients, aged 2 to 72 months of age, with an uncomplicated intussusception, that were treated by barium or air enema, were studied. RESULTS: The success rate was 73% with barium reductions, and 100% with air reductions. In 17 patients (24%), enema reduction was unsuccessful and were subjected to a surgical reduction. CONCLUSIONS: Nonsurgical reduction is safe and effective as the initial treatment of uncomplicated intussusception in children.

Air↗
PubMed2000

[Vegetal foreign body in the airway: an unusual cause of hemoptysis in childhood. Clinical case].

Hemoptysis is an infrequent symptom in childhood and potentially life threatening. The most common causes in this age group are bronchiectasis secondary to cystic fibrosis, cardiovascular and pulmonary congenital anomalies and a miscellaneous group of causes including retained intrabronchial aspirated foreign bodies. We report a previously healthy 5-year-old girl with recurrent pneumonias associated with episodes of hemoptysis. She was admitted in our institution to investigate the persistence of hemoptysis. Based on clinical history, aspiration of a vegetal foreign body was postulated as the etiology and it was confirmed in the pathological examination after surgical exploration, with pulmonary lobe resection. The importance of a good history taking in pediatric hemoptysis is emphasized.

Bronchi↗
PubMed2000

[Bronchiolitis obliterans with organizing pneumonia secondary to chemotherapy in a child with primary pericardial sarcoma].

The uncommon bronchiolitis obliterans organizing pneumonia can be idiopathic or caused by infection or medications. We report a 5 year old boy with pericardial sarcoma that was treated with chemotherapy (vincristine, doxorubicin, etoposide, cyclophosphamide) and radiotherapy. During the third cycle of chemotherapy, he developed progressive cough and dyspnea, needing oxygen therapy. Chest X-ray examination showed bilateral infiltrates. After discarding infectious etiologies, an open lung biopsy was performed, and the pathological examination showed a bronchiolitis obliterans organizing pneumonia. He was treated with prednisolone for 7 days, followed by prednisone for additional 45 days. He continued with fluticasone propionate as maintenance and remains in good condition with a chest X-ray showing mild interstitial images, after seven months of follow up.

Antineoplastic Agents↗
PubMed2000

[Presence of conjugative transposon Tn1545 in strains of Streptococcus pneumoniae with mef(A), erm(B), tet(M), catpC194 and aph3'-III genes].

We studied the association of MLS resistance genes (erm(B) and mef(A) with others non-MLS resistance genes: tet(M) (tetracycline and minocycline), catpC194 (chloramphenicol) and aph3'-III (kanamycin) in order to know how is selected the multiresistant in Streptococcus pneumoniae. The tet(M) and catpC194 genes were present very often in the pneumococci with the erm(B) gene but the aph3'-III was found only in four strains. Tn1545 was nearly always the responsible for the dissemination of these genes. In contrast, mef(A) was not associated with tet(M) and and catpC194 and is disseminated in a different conjugative transposon. The linkage of multiple antibiotic resistance genes on the same mobile element is of importance for public health, because the use of one antibiotic selects for the transposon which carries multidrug resistance genes.

Anti-Bacterial Agents↗