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Biomedical subjects

J Garcia

Publications and source records attributed to J Garcia.

At least 163 records · Page 9Linked to original sources
PubMed1997

Errors in the selection of dialysate concentrates cause severe metabolic acidosis during bicarbonate hemodialysis.

Severe metabolic acidosis occurred during bicarbonate hemodialysis as the result of an error made in the selection of the dialysate concentrate. We questioned whether or not it was possible for the dialysis equipment to regulate the proportions in the dialysate fluid using an incorrect dialysate concentrate and still obtain the proper conductivity. We simulated this situation in vitro and found that during bicarbonate dialysis an inappropriately acidic dialysate fluid could replace the normal dialysate with an adequate range of conductivity still being maintained and therefore no triggering of alarms. The investigation showed that the dialysis machines were not adequately adjusted for sensitivity to the concentrates being employed during dialysis. We concluded that dialysis equipment should be fitted with on-line pH meters with alarm systems.

Acidosis↗
PubMed1997

Predicting poor neonatal outcome: a comparative study of noninvasive antenatal testing methods.

OBJECTIVE: The assessment of fetal well-being in the third trimester of pregnancy depends on many variables including fetal size, amniotic fluid volume, umbilical cord arterial Doppler waveforms, the nonstress test, and the biophysical profile, yet little has been written that directly compares these variables. In this study, we compared amniotic fluid indexes, umbilical cord arterial Doppler waveforms, nonstress tests, and biophysical profiles for predicting poor neonatal outcomes in fetuses who are small for gestational age (SGA). SUBJECTS AND METHODS: From April 11, 1994, through August 1, 1995, a cohort of 108 SGA fetuses was identified. Follow-up was available in 97 of these cases. Receiver operating characteristic curves were constructed for Doppler systolic:diastolic ratios and for amniotic fluid indexes. Student's t test and logistic regression analysis were used to compare umbilical cord arterial Doppler imaging, amniotic fluid indexes, the nonstress test, and the biophysical profile for predicting poor neonatal outcome. RESULTS: Of the 30 fetuses who had poor outcomes, five were emergency cesarean deliveries, three died, three had intracranial hemorrhages, one had a cerebral infarct, 12 had prolonged admission to the neonatal intensive care unit (NICU) (> 10 days), and six had NICU admissions at term. Of the variables we assessed, the sensitivities for predicting poor outcome were as follows: cord Doppler imaging, 64%; low amniotic fluid volume (oligohydramnios), 32%; biophysical profile, 18%; and nonstress test, 14%. Receiver operating characteristic curves showed that a systolic:diastolic ratio of 4.0 and an amniotic fluid index of 5 cm (independent of gestational age) were the most accurate cutoff values for predicting poor outcome. Logistic regression analysis showed that amniotic fluid indexes and umbilical cord arterial Doppler imaging were independent predictors of poor outcome and that the predictive value of the biophysical profile varied according to the amniotic fluid index. CONCLUSION: Doppler waveform abnormalities were the most accurate predictor of poor neonatal outcome in a cohort of SGA fetuses. Umbilical cord arterial Doppler waveform analysis should be included in the surveillance of SGA fetuses.

Amniotic Fluid↗
PubMed1997

[Magnetic resonance imaging in meniscal bucket-handle tears].

PURPOSE: To define MR signs of meniscal bucket-handle tears and evaluate the diagnostic efficiency of this technique. MATERIALS AND METHODS: Retrospective study of 30 patients with a meniscal bucket-handle tear and 30 with a different type of tear, all proven by arthroscopy. The following MR signs of a bucket-handle tear were evaluated: "separate meniscal fragment", "double posterior cruciate ligament", "snake sign" and "double anterior hom". RESULTS: A correct diagnosis of a bucket-handle tear was only made in 18/30 of patients. Several of the MR signs were seen in the same patient in 17 cases. A double posterior cruciate ligament was present only in cases of medial meniscus tears. The 12 menisci without these signs, and therefore not diagnosed as bucket-handle tears, were all classified as meniscal tears on the basis of signal extending to the meniscal surface. Nine of these were not displaced into the intercondylar notch at arthroscopy. The interobserver agreement was excellent: kappa = 0.88. CONCLUSION: The diagnosis of a bucket-handle meniscal tear, if it is displaced, can be made when one or more of the four MR evaluated signs are present. Other forms of meniscal tears are only exceptionally diagnosed as bucket-handle tears.

Adolescent↗
PubMed1997

[Aseptic osteonecrosis of the femoral condyle after meniscectomy by the arthroscopic approach].

Retrospective review of 10 patients who presented with avascular necrosis of the ipsilateral femoral condyle following arthroscopic meniscectomy (9 medial, 1 lateral). The bone lesions were evaluated by radiography and MRI, which were repeated for few patients. MRI allows earlier diagnosis of avascular necrosis of the femoral condyle and offers an evaluation of extent of the lesions whose evolution is variable: 3 patients required a knee prothesis, the other 7 patients were treated medically.

Aged↗
PubMed1997

Recurrent severe infantile cortical hyperostosis (Caffey disease) in siblings.

Infantile cortical hyperostosis (ICH), Caffey disease, is a multifocal, inflammatory skeletal process with classic onset before the fifth month of life and resolution by the age of 3 years. A severe phenotype with early prenatal onset has also been described. Inheritance is generally accepted a autosomal dominant with variable expression and penetrance. However, occurrence in siblings with no family history has been reported, raising the possibility of heterogeneity and the existence of a severe autosomal recessive form. We describe a third family with prenatally diagnosed ICH in two siblings, providing further evidence for this form of inheritance.

Adult↗
PubMed1997

Allergic reactions to ampicillin. Studies on the specificity and selectivity in subjects with immediate reactions.

BACKGROUND: Ampicillin (AMP) is a drug that has been prescribed extensively. Reactions that have been reported include exanthema, desquamative contact eczema, urticaria and anaphylaxis. Experimental evidence indicates that the side chain of AMP is a structure that may induce a selective immune response either at the humoral or lymphocyte T-cell level. With regard to IgE reactions, the selectivity and specificity of the response needs to be studied in humans. OBJECTIVES: To study the specificity of the IgE response in a group of subjects who had an immediate allergic reaction after the administration of AMP. METHODS: Subjects developing an immediate response (anaphylaxis or urticaria) after the administration of AMP or an aminopenicillin derivative with the same side chain as AMP were studied. Skin tests were made to determinants generated from benzyl penicillin (BP): benzyl penicilloyl (BPO) and minor determinant mixture (MDM), as well as amoxicillin (AX) and AMP. Specific IgE antibodies were determined to benzyl penicilloyl polylisine (BPO-PLL), amoxicilloyl-polylisine (AX-PLL) and ampicilloyl-polylisine (AMP-PLL). The specificity of the IgE antibody response was studied by RAST and RAST inhibition. Subjects were classified in three categories: group A: those who were skin test and/or RAST positive to determinants derived from benzylpenicillin, group B: those who were negative to determinants derived from benzylpenicillin but were skin test and/or RAST positive to determinants derived from AX and AMP and group C: those who were exclusively positive to determinants derived from AMP. RESULTS: A total of 48 subjects was included in the study. In group A there were 35 cases, in group B 10 cases, and in group C three cases. RAST inhibition studies showed that in some instances the side chain of AMP could induce specific responses with a variable degree of crossreactivity between BP and AX. CONCLUSIONS: Although AMP can induce an immediate IgE response in subjects allergic to betalactams and the structure of the side chain may contribute to the specificity of the response, our results indicate that in most instances crossreactivity with the other penicillins exists and that in the groups studied selective reactions to just AMP derived determinants were uncommon.

Adult↗
PubMed1996

Brachmann-de Lange syndrome: autosomal dominant inheritance and male-to-male transmission.

We report on familial occurrence of the Brachmann-de Lange syndrome (BDLS): a mildly affected father and his severely affected son and daughter who have different mothers. Both children are severely affected while the father has a much milder but definite BDLS phenotype. Our report documents the third example of male-to-male transmission and adds to the argument against exclusively maternal transmission in familial cases. In addition, our findings illustrate the occurrence of severe manifestations in cases of familial BDLS.

Adult↗
PubMed1996

[Endoscope-assisted laparoscopic resection of the gastric wall].

The early gastric carcinomas measuring 10-25 mm in diameter, macroscopically I-II/C types and benign gastric tumours are relegated to laparoscopic wedge resection of the stomach. Authors report on the use of a new endoscopic assisted--"double-lifting"--laparoscopic resection of the gastric wall, in the course of removal of an early stage gastric carcinoma (13 mm in diameter, macroscopically II/C type) and a gastric lipoma (21 mm in diameter). The advantage of this method: the affected gastric wall could be removed safely far from the lesion and all layers of the gastric wall are available for histological examination.

Adult↗
PubMed1996

[Epidemiology of acute bronchopulmonary infections in children].

In infants and young children acute lower respiratory infection is the most common cause of morbidity and death especially in developing countries. Factors that contribute to the increased susceptibility to respiratory pathogens include young age, season, sex, indoor pollution, large family size, malnutrition, low immunocompetence, socioeconomic disadvantage. The epidemiology of acute respiratory infections in childhood seems similar worldwide. In all countries, respiratory syncytial virus, parainfluenzae virus 1 and 3 influenzae A and B viruses and adenovirus are reported to be the main causes of acute respiratory infections. Six microorganisms are responsible of 90% of documented acute bacterial pulmonary infections, Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia trachomatis, Haemophilus influenzae, Staphylococcus. Mixed viral and bacterial infections occur frequently (30%). The role of respiratory viruses in predisposing to colonization and invasion of bacterial organisms has often been suggested. In recent years acquired resistance against antibiotic for H. influenzae and S. pneumoniae has emerged.

Acute Disease↗
PubMed1996

Quantitation of the density of cell surface carbohydrate antigens on cancer cells with a sensitive cell-suspension ELISA.

The density of carbohydrate epitopes on the surface of tumor cells is a governing factor for immune recognition and antibody-mediated targeting of tumor-associated carbohydrate antigens in cancer immunotherapy. A sensitive cell-suspension ELISA (cs-ELISA) is developed for quantitation of the functionally exposed carbohydrate epitopes on the cell surface. The factors affecting the measurement of tumor-cell surface glycoconjugates are evaluated using three human melanoma cell lines before and after exposure to various cell preservation treatments. The results of cs-ELISA are compared with the quantitative profile obtained by biochemical and flow cytometry assays. Cs-ELISA measures the density of the functionally exposed specific sugar epitopes on the surface of tumor cells, even in the presence of other similar carbohydrate antigens, provided that the monoclonal antibodies to carbohydrate epitopes are monospecific and sensitive, and that the cells are viable and present in optimal density. Of the three melanoma cell lines, M10-v and M101 expressed disialolactosyl residues of GD3 at concentrations of 5-6 pmol/10(6) cells and 2-3 pmol/10(6) cells, respectively. In both cell lines, the cell-surface GD2 was less than 1.0 pmol/10(6) cells. M24 melanoma cells expressed trace quantities (< 0.1 pmol/10(6) cells) of GD3 and GD2. Trypsinization of M10-v and M101 cells significantly reduced the cell-surface expression of GD3, suggesting GD3 loss, but increased the expression of GD2, suggesting crypticity of membrane-bound GD2. Cs-ELISA results showed that cryopreservation with 10% DMSO and irradiation at 15 krad decreased melanoma cell viability and ganglioside expression for M10-v but not M101 and M24. Formalinization did not affect cs-ELISA measurement of cell-surface carbohydrates. Cs-ELISA was used to monitor the quantity of incorporation of exogenous GD3 onto the surface of GD3-deficient M24 cells. Cs-ELISA for assessment of density of cell surface carbohydrate epitopes may be useful to characterize different types of tumors, to develop carbohydrate-based whole cell vaccines from tumor biopsies, to monitor the effects of cell preservation treatments commonly used in a whole cell vaccine preparation, and to evaluate the incorporation of a particular glycolipid (antigen or adjuvant) into glycolipid-deficient cells that are useful for carbohydrate-based active specific immunotherapy.

Antibodies, Monoclonal↗
PubMed1996

Effect of polyunsaturated fatty acids deficiency on oxidative phosphorylation in rat liver mitochondria.

Liver mitochondria isolated from controls or polyunsaturated fatty acid (PUFA) deficient rats were studied for oxidative phosphorylation. A PUFA-deficient diet led to a dramatic change in the fatty acid composition of mitochondrial lipid content, similar to that reported in the literature. Besides the changes in lipid composition, mitochondrial volume was enlarged (+45% in state 4 and two-fold in state 3). State 4 respiration was increased together with a decrease in protonmotive force. The non-ohmicity of the relationship between non-phosphorylating respiration and protonmotive force was more pronounced in the PUFA-deficient group. State 3 oxygen consumption as well as the rate of ATP synthesis showed no difference between the two groups, whereas the protonmotive force decreased substantially in mitochondria from PUFA-deficient animals. In contrast, ATP/O ratios were decreased in the PUFA-deficient group when determined at subsaturating ADP concentration. Taken together, these results are in agreement with both an increased non-ohmic proton leak and an increased redox slipping. The relative importance of these two effects on the overall efficiency of oxidative phosphorylation depends on both the rate of oxidative phosphorylation and the maintained protonmotive force. Hence, in isolated mitochondria the respective role of each effect may vary between state 4 and state 3.

Adenosine Triphosphate↗
PubMed1996

[Magnetic resonance imaging of the locomotor apparatus].

A multiplanar approach and a good tissue differentiation characterize magnetic resonance imaging which have a great role in exploring numerous musculo-skeletal lesions; review of main indications and limits. MRI is useful in diagnosing certain undisplaced fractures, fatigue and insufficiency fractures, and consequences. Fibrous cartilage and hyalin cartilage lesions, tears of tendons, ligaments and muscles are well appreciated. MRI is also very good for an early and correct diagnosis of avascular necrosis, spinal degenerative lesions, spinal consequences of rheumatoid arthritis and ankylosing spondylitis, and bone metastases. It is the technique of choice for local staging of bone and soft tissue sarcomas.

Bone Neoplasms↗
PubMed1996

Light microscopic detection of sugar residues in rabbit embryo teeth with lectin-horseradish peroxidase conjugates.

We investigated the binding of five HRP-conjugated lectins to rabbit tooth germs at the cap and late bell stages of development. The results revealed some changes in the glycosylation patterns of the glycoconjugates. Sugar residues, such as alpha-D-mannose, methyl-D-glucose, N-acetylglucosamine, beta-D-galactosamine, D-galactose, and sialic acid, were detectable in some components of the tooth germs. The most conspicuous developmental change was increased binding of Con A and WGA. These lectins showed, at the cap stage, moderate binding to the (pre)-ameloblasts and (pre)-odontoblasts. With further development to the late bell stage, but prior to the achievement of well-defined morphological-functional characteristics, the odontoblasts and ameloblasts displayed considerable amounts of alpha-D-mannose, alpha-D-glucose as well as beta-D-acetylglucosamine and sialic acid. Appropriate control studies confirmed the specificity of the binding of the lectins. Two lectins (DBA and PNA) with known specificity for N-acetylgalactosamine groups were bound by the basement membranes in tooth germs at the cap stage. A third lectin (RCA) with the same specificity did not produce any detectable staining in the same material. Further studies must be planned to determine the specific functions and significance of lectin-HRP-binding glycoconjugates in odontogenesis.

Animals↗