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Biomedical subjects

E Garcia

Publications and source records attributed to E Garcia.

At least 127 records · Page 7Linked to original sources
PubMed1995

An integrated metric physical map of human chromosome 19.

A metric physical map of human chromosome 19 has been generated. The foundation of the map is sets of overlapping cosmids (contigs) generated by automated fingerprinting spanning over 95% of the euchromatin, about 50 megabases (Mb). Distances between selected cosmid clones were estimated using fluorescence in situ hybridization in sperm pronuclei, providing both order and distance between contigs. An average inter-marker separation of 230 kb has been obtained across the non-centromeric portion of the chromosome. Various types of larger insert clones were used to span gaps between contigs. Currently, the map consists of 51 'islands' containing multiple clone types, whose size, order and relative distance are known. Over 450 genes, genetic markers, sequence tagged sites (STSs), anonymous cDNAs, and other markers have been localized. In addition, EcoRI restriction maps have been generated for > 41 Mb (approximately 83%) of the chromosome.

Base Sequence↗
PubMed1995

Long-term cultured CD40-activated B lymphocytes differentiate into plasma cells in response to IL-10 but not IL-4.

We compared the effects of IL-10 and IL-4 on the functions of B lymphocytes triggered through their CD40. During the initial phase, IL-10 was as potent as IL-4 in inducing the expansion of viable B cells. Then, cellular expansion slowed down and after approximately 3 weeks the number of B cells started to decline. While the combination of IL-10 and IL-4 was synergistic during the first 2 weeks of culture, B cell recovery declined after 3 weeks, indicating that IL-10 prevails over IL-4. Those effects were not restricted to a specific B cell subset as both sIgD+ B cells and sIgD- B cells behaved in a similar way, though the latter population responded with a slightly accelerated kinetic. Inverted microscope examination and scanning electron microscopy showed that in response to IL-10, CD40-activated B cell cultures were heterogeneous with loose aggregates of cells as well as free floating large ovoid cells. In contrast, in the presence of IL-4, CD40-activated B cell cultures were essentially composed of tight cell clumps. IL-10 progressively induced all B cells to differentiate into non-replicating cells with intracytoplasmic Ig that secreted Ig at a high rate. Cytologic analysis indicated that IL-10 cultured cells display a basophilic cytoplasm with an arcoplasm and a low nucleus/cytoplasm ratio. Transmission electron microscopy demonstrated that when IL-10 was added to the culture, B cells displayed structures for excretion with extended endoplasmic reticulum and dilated cisternae containing paracrystalline structures, typical of plasmablasts cells. Taken together, these results indicate that IL-10 acts as a plasma cell differentiation factor for CD40-activated B cells.

Antibody-Producing Cells↗
PubMed1995

Antigens from Taenia crassiceps cysticerci used in complement fixation, enzyme-linked immunosorbent assay, and western blot (immunoblot) for diagnosis of neurocysticercosis.

Antigens from Taenia solium cysticerci for the immunodiagnosis of cysticercosis are scarce and difficult to obtain. We studied the reliability of antigens from Taenia crassiceps cysticerci as a substitute for those from T. solium in three diagnostic tests: complement fixation, enzyme-linked immunosorbent assay, and Western blot (immunoblot). Precision rates of the three tests of 93, 99, and 96%, respectively, were found. Cysticerci from T. crassiceps can be easily obtained in large quantities and can be effectively used for the diagnosis of human neurocysticercosis.

Animals↗
PubMed1995

Diagnosis of American trypanosomiasis (Chagas' disease) by the new complement fixation test.

A new immunodiagnostic method of complement fixation was used for serodiagnosis of American trypanosomiasis; 92% sensitivity and 99% specificity were obtained, for an overall accuracy of 97%. This test can be used in field studies, obviating the use of most laboratory equipment and imported reagents; places where economic limitations hinder the use of other immunodiagnostic procedures; and in association with other tests for confirmation of the diagnosis.

Animals↗
PubMed1995

FISH analyses of a newly established thyroid tumor cell line showing a t(1;19)(p35 or p36.1;q13) reveal that the breakpoint lies between 19q13.3-13.4 and 19q13.4.

Translocations involving the long arm of human chromosome 19 are specific chromosomal alterations found in a subset of benign thyroid tumors. In the present communication we describe the establishment of an SV40-transformed cell line derived from a thyroid adenoma with a t(1;19)(p35 or p36.1;q13). Cytogenetic studies were carried out on this cell line, using a series of cosmids mapping along the long arm of chromosome 19. In situ hybridization with probes for RYR1, ATP1A3, BCKDHA, ERCC1, POLD1, and TRPT revealed that only TRPT mapped distal to the breakpoint of the translocation. The results indicated that the breakpoint is located between POLD1 and TRPT at the boundary between chromosome bands 19q13.3 and 19q13.4.

Chromosomes, Human, Pair 1↗
PubMed1995

Molecular analysis of a novel subtelomeric repeat with polymorphic chromosomal distribution.

DNA from a 50-kb yeast artificial chromosome (YAC) containing one human telomere was characterized. Cloned sequences from the centromeric end of this YAC (designated yRM2001) localized to several human chromosomes by somatic hybrid panel mapping. The telomeric end of the YAC contained both (TTAGGG)n sequences and the previously characterized TelBam3.4 subterminal repeat element. A novel low-copy repeat element (designated HC1103) mapped 19 kb from the telomeric end of the YAC. This repeat was shown by fluorescence in situ hybridization to be present in several subtelomeric regions (3q, 12p, 15q, 19p, and 20p) and at an interstitial site (2q13-->q14) in all individuals studied, but to be polymorphically distributed at several other telomeres. The YAC vector-insert EcoRI cloning site was positioned 50 kb to 70 kb from chromosome termini in human genomic DNA using RecA-assisted restriction endonuclease (RARE) cleavage analysis. Our results suggest that the DNA segment cloned in yRM2001 contains a novel block of low-copy DNA consistently present at some human telomeres, but polymorphically distributed at others.

Base Sequence↗
PubMed1995

Growth hormone (GH) responses to the combined administration of GH-releasing hormone plus GH-releasing peptide 6 in adults with GH deficiency.

In recent years the health problems of adults with growth hormone deficiency (GHD) and the benefits of GH replacement therapy have received considerable attention. However, the reliability of conventional GH tests in the assessment of pituitary GH reserve in this group of patients is still controversial. In this study, we assessed GH secretion after the combined administration of GH-releasing hormone (GHRH) (1 microgram/kg iv) and GH-releasing peptide 6 (GHRP-6, 1 microgram/kg iv) in adult patients diagnosed with GHD by conventional GH testing, and correlate this response with insulin-like growth factor I levels. Twenty-one subjects (13 male, 8 female) with long-standing diagnosis of GHD aged 21-54 years were studied. In 13 subjects GH responses to GHRH plus GHRP-6 were markedly reduced (peak GH response < 10 mU/l), whereas in the remaining eight the response was greater (range 11-100 mU/l). In conclusion, our data show that combined administration of GHRH plus GHRP-6 elicited a significant increase in plasma GH levels in about 40% of patients diagnosed with GHD by conventional GH testing.

Adult↗
PubMed1994

The relationship between pes cavus and idiopathic scoliosis.

STUDY DESIGN: The incidence of pes cavus and scoliosis was studied in three groups of patients. Group A contained 130 patients with idiopathic scoliosis, Group C contained 210 patients with idiopathic pes cavus, and Group B (control) contained 200 patients of similar age. OBJECTIVES: To investigate the joint presentation of pes cavus and idiopathic scoliosis, because both deformities may share a common etiology linked to muscle imbalance. SUMMARY OF BACKGROUND DATA: Sixty five percent of Group A patients (85 of 130) had an abnormally high plantar arch, compared to only 9.5% (19 of 200) of Group B control subjects. Nine percent (20 of 210) of the patients in Group C had scoliosis curves, compared to only four patients in Group B. METHODS: Radiographs were taken to determine the type of scoliosis curve, its location, and its magnitude, and to identify the incidence of spina bifida occulta in the three groups. The incidence and degree of pes cavus were established by means of foot prints. Statistical analyses were performed on all results. RESULTS: A statistically significant relationship (P < 0.01) was found for the incidence of pes cavus between Group A (scoliosis) and Group B (control), and for the incidence of scoliosis between Group C (pes cavus) and Group B (control). No statistical significance was observed for the other relationships investigated (sex, curve location, magnitude, spina bifida). CONCLUSIONS: There was a significant correlation between scoliosis and pes cavus--spina bifida was not an etiologic factor. Therefore, in certain patients where scoliosis and pes cavus present jointly, deformity may be secondary to altered balance or to disorders of the central nervous system.

Adolescent↗
PubMed1994

Risk and benefit of low systemic heparinization during open heart operations.

Heparin surface-coated perfusion equipment with improved thromboresistance was evaluated in 104 consecutive patients undergoing open heart operation in a prospective, randomized trial with low versus full systemic heparinization. Surgical procedures included coronary artery revascularization in 47 of 54 (87%) for low versus 44 of 50 patients (88%; not significant [NS]) for full, valve repair/replacement in 8 of 54 (15%) for low versus 5 of 50 patients (10%; NS) for full, left ventricular aneurysm repair in 1 of 54 (2%) for low versus 2 of 50 patients (4%; NS) for full, and other in 3 of 54 (6%) for low versus 3 of 50 patients (6%; NS) for full. Cross-clamp time was 39.2 +/- 10.7 minutes for low versus 39.5 +/- 10.5 minutes for full (NS). Cardiopulmonary bypass time was 68.6 +/- 20.1 minutes for low versus 69.3 +/- 16.6 minutes for full (NS). Lowest activated coagulation time during perfusion was 255 +/- 75 seconds for low versus 537 +/- 205 seconds for full (p < 0.0005). In the low group, the target activated coagulation time of more than 180 seconds was not reached during perfusion in 4 of 54 patients (7%), the lowest value being 164 seconds. No oxygenator failure occurred. Hospital mortality was 0 of 54 (0%) for low versus 1 of 50 patients (2%) for full (NS). Bleeding required surgical revision in 0 of 54 (0%) for low versus 4 of 50 patients (8%) for full (p = 0.05). Drainage (24 hours) was 790 +/- 393 mL for low versus 1,039 +/- 732 mL for full (p < 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation↗
PubMed1994

Chromatographic resolution of the type II estrogen binding site and a tyrosinase-like enzymatic activity from rat uterine nuclei.

Nuclear extracts from estradiol-treated rat uteri which contain type II estrogen binding sites have recently been found to also contain a tyrosinase-like estradiol metabolizing activity. A recent study suggested that both the binding and enzymatic activities are significantly increased in the presence of micromolar concentrations of copper and ascorbate, display a number of common biochemical sensitivities, and share similar ligand/substrate binding affinities. Levels of both activities are significantly increased in uterus in response to hormone (estrogen) stimulation. These and other similarities indicate a possible relationship between the enzymatic and binding activities. A detailed chromatographic examination of these two activities in the present study revealed that while the type II sites and estradiol metabolizing activity exhibited virtually identical chromatographic properties on DEAE-high-performance liquid chromatography they are readily resolved on other chromatographic matrices, including phosphocellulose, DNA-cellulose, and S-Sepharose. These results demonstrate that type II binding sites are distinct from the tyrosinase-like enzyme activity previously described in rat uterine nuclear extracts.

Animals↗
PubMed1994

Tryptophan and its metabolites in patients on continuous ambulatory peritoneal dialysis and following renal transplantation.

Plasma tryptophan (Trp) concentration in its total (TTrp) and non-protein-bound free form (FTrp) and its metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) as well as muscle Trp contents (MTrp) were studied in 12 uraemic patients undergoing continuous ambulatory peritoneal dialysis (CAPD), 10 renal transplant patients, and 10 healthy control subjects. The CAPD patients exhibited signs of muscle weakness, as assessed by dynamometry, and signs of protein malnutrition with a decreased ratio of alkali-soluble protein relative to DNA in muscle as well as low serum albumin concentration. In the uraemic patients TTrp was markedly reduced, whereas in the transplant patients it did not differ from the controls. The FTrp, which was separated by the process of equilibrium dialysis, was less in the uraemic (P < 0.01) as well as transplant patients (P < 0.01) than in the controls. The plasma FTrp/TTrp ratio was increased in the uraemic patients (40 +/- 8%) but less in the transplant patients (16 +/- 4%), as compared to the controls (25 +/- 5%). The uraemic patients had increased plasma concentrations of 5-HIAA, whereas this metabolite could not be found in the plasma of renal transplant patients and healthy controls. MTrp was increased by an average of 33% in the uraemic patients whereas it did not differ between the transplant patients and the controls. The results indicate that the abnormal Trp metabolism in uraemic patients is to a large extent corrected by a successful renal transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Chronic eosinophilic pneumonia as a presenting feature of Churg-Strauss syndrome.

We report on a case of Churg-Strauss syndrome in a 30 year old male with a history of perennial rhinitis. The syndrome began nine months earlier with clinico-radiological features typical of chronic eosinophilic pneumonia. Diagnosis of vasculitis was made by skin biopsy, and at that time there was multisystemic involvement with pulmonary, cardiac, renal, cutaneous and muscular disease, and right vocal chord paralysis, which improved with corticosteroids and cyclophosphamide. This case report illustrates the possible overlap of chronic eosinophilic pneumonia and the Churg-Strauss syndrome.

Adult↗
PubMed1993

Electroconvulsive shock does not modify striatal contents of dopamine in MPTP-treated mice.

It has been suggested that the therapeutic response to electroconvulsive therapy in depressed patients could be mediated by functional changes in the dopaminergic pathways; a favorable response to electroconvulsive therapy was also observed recently in patients with Parkinson's disease. To study a possible interference of electroconvulsive shock in the course of MPTP-induced parkinsonism in rodents, we measured the striatal content of dopamine in MPTP-treated mice that received electroconvulsive shock at various intervals in the course of MPTP neurotoxicity. Our results showed no immediate or delayed differences in striatal dopamine content of animals that received MPTP and electroconvulsive shock when compared with animals that received only MPTP, thus suggesting that the strong biological effects of MPTP and electroconvulsive shock on the brain may follow different biochemical mechanisms.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗