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Biomedical subjects

J Coll

Publications and source records attributed to J Coll.

At least 19 recordsLinked to original sources
PubMed1992

Human endothelial cells transfected by SV40 T antigens: characterization and potential use as a source of normal endothelial factors.

A putative role for the vascular endothelium as target for autoantibodies has been suggested in several autoimmune disorders and connective-tissue diseases. However, there are some difficulties linked to the use of cultured endothelial cells (EC) that limit considerably the extensive studies on the nature of endothelial target antigens involved. To overcome this problem, human EC, derived from umbilical veins, were transfected with recombinant plasmid pSV1 which contained the early genes of simian virus SV40. These transfected cells, called EC-pSV1, are able to grow without EC growth supplement and demonstrate a population doubling time of about 50 h. Among the EC properties, EC-pSV1 retain intracellular content of angiotensin-converting enzyme activity, exhibit constitutive production of interleukin 6 and of a growth-promoting activity on early passage EV, express intercellular adhesion molecule 1 (ICAM-1) and its up-regulation by tumor necrosis factor alpha, but have lost the expression of factor VIII-related antigen. Moreover, EC-pSV1 express a 55-kDa antigen found on EC and human platelets, and presumably acting as an antibody target in some cases of non-allergic asthma. However, at the 50-55th generation, morphological changes and altered growth behavior were visible. This work demonstrates that transfection of EC with SV40 T antigens may be of interest, particularly in areas of research including the study of EC targets involved in different human diseases.

Antigens, Polyomavirus Transforming↗
PubMed1992

Evolution of the nuclear receptor gene superfamily.

Nuclear receptor genes represent a large family of genes encoding receptors for various hydrophobic ligands such as steroids, vitamin D, retinoic acid and thyroid hormones. This family also contains genes encoding putative receptors for unknown ligands. Nuclear receptor gene products are composed of several domains important for transcriptional activation, DNA binding (C domain), hormone binding and dimerization (E domain). It is not known whether these genes have evolved through gene duplication from a common ancestor or if their different domains came from different independent sources. To test these possibilities we have constructed and compared the phylogenetic trees derived from two different domains of 30 nuclear receptor genes. The tree built from the DNA binding C domain clearly shows a common progeny of all nuclear receptors, which can be grouped into three subfamilies: (i) thyroid hormone and retinoic acid receptors, (ii) orphan receptors and (iii) steroid hormone receptors. The tree constructed from the central part of the E domain which is implicated in transcriptional regulation and dimerization shows the same distribution in three subfamilies but two groups of receptors are in a different position from that in the C domain tree: (i) the Drosophila knirps family genes have acquired very different E domains during evolution, and (ii) the vitamin D and ecdysone receptors, as well as the FTZ-F1 and the NGF1B genes, seem to have DNA binding and hormone binding domains belonging to different classes. These data suggest a complex evolutionary history for nuclear receptor genes in which gene duplication events and swapping between domains of different origins took place.

Amino Acid Sequence↗
PubMed1992

Pulmonary tuberculosis in HIV-infected patients with normal chest radiographs.

SUBJECTS: Three HIV-infected patients with active pulmonary non-disseminated tuberculosis and normal chest radiograph at clinical presentation and during follow-up are reported. Patients had cough and fever but no other specific symptoms. Löwenstein cultures of specimens from bronchoalveolar lavage in two cases and induced sputum in one yielded Mycobacterium tuberculosis. CONCLUSIONS: The diagnosis of tuberculosis in HIV-infected patients depends greatly on clinical suspicion by the physician, because of its atypical presentation. Failure to perform appropriate diagnostic tests in HIV-infected patients who present with suspected pulmonary disease will result in underdiagnosis and undertreatment of tuberculosis.

Adult↗
PubMed1992

Human irritant response to different qualities and concentrations of cocoamidopropylbetaines: a possible model of paradoxical irritant response.

Cocoamidopropylbetaines are surfactants frequently used in cosmetics. We have evaluated the irritant capacity of 3 different qualities of cocoamidopropylbetaine, using the following method: patch tests have been carried out with 5 different dilutions in 67 patients and the results read at 2 days by noninvasive methods (direct visualization, transepidermal water loss (TEWL), laser Doppler flowmetry (LDF)). The results with the 3 methods were concordant. However, the results with the different concentrations were paradoxical, as irritancy did not increase at higher concentrations. We have tried to explain this by the fact that these substances contain by-products (free amidoamine and sodium monochloroacetate), the concentrations tested all being above the critical micelle concentration and therefore containing both micelles and monomer. Finally, we believe that noninvasive methods such as TEWL and LDF could be of great use in the evaluation of irritant contact dermatitis.

Adult↗
PubMed1992

Sjögren's syndrome: a stepwise approach to the use of diagnostic tests.

One hundred and forty two patients (62 with definite Sjögren's syndrome, 24 with probable Sjögren's syndrome, and 56 in whom Sjögren's syndrome was finally ruled out) were studied. Schirmer's test and rose bengal staining for the diagnosis of keratoconjunctivitis sicca and salivary scintigraphy and a labial biopsy sample for the diagnosis of xerostomaia were studied in all patients. Rose bengal staining showed high specificity (98%) but low sensitivity (55%). All patients with positive rose bengal staining results had associated xerostomia. In the rose bengal staining positive patients, scintigraphy had 100% specificity. A labial biopsy sample showed high sensitivity in the rose bengal staining, salivary scintigraphy positive group, and high specificity in the rose bengal staining positive, salivary scintigraphy negative group. In patients with negative rose bengal staining, salivary scintigraphy showed 96% specificity and 36% sensitivity. A labial biopsy sample had a sensitivity and specificity greater than 90% in rose bengal staining negative patients. Only 29 biopsy samples were needed to achieve a diagnosis of Sjögren's syndrome in 142 patients (20%). Hence the suggested approach may make it unnecessary to take biopsy samples in approximately 80% of patients with suspected Sjögren's syndrome. Using the stepwise approach of first rose bengal staining, then salivary scintigraphy, and eventually a labial biopsy sample in patients with suspected Sjögren's syndrome, the diagnosis is relatively simple.

Adult↗
PubMed1992

Clinical and non-invasive evaluation of 12% ammonium lactate emulsion for the treatment of dry skin in atopic and non-atopic subjects.

Clinical dryness of the leg skin is a common problem among dermatological patients. The efficacy and safety of 12% ammonium lactate emulsion (Keratisdin) for the treatment of dry skin on the legs of atopic and non-atopic subjects has been assessed by clinical criteria and by five different non-invasive methods. These methods measure biophysical parameters such as electrical capacitance of stratum corneum, skin surface lipids, transepidermal water loss (TEWL), skin surface topography (scanning electron microscopy and image analysis) as well as the biomechanical properties of the skin. Treatment with the test emulsion significantly reduced the severity scores for dryness, desquamation and pruritus when measured 15 days later. All patients tested showed a significant increase in electrical capacitance, skin surface lipids, extensibility and firmness of the skin, and an improvement in the skin barrier function and skin surface topography. This study showed that non-invasive techniques are excellent complementary tools in clinical studies.

Adult↗
PubMed1992

Implementing total quality management in the Spanish health care system.

A Total Quality Management Programme for the Spanish Health Care System was set in motion in 1986. The first phase of the programme covers three areas: (1) information sources, (2) training, (3) Total Quality activities, through a cascade of four coordinated projects. The first one defines a basic nucleus of patient information and established two national standards: (a) a minimum basic data set, (b) the use of an ICD-9-CM Spanish translation for codification of diagnoses and procedures. The second is an open demonstration project implementing these two standards in National Health Service hospitals and carrying out intensive training on ICD-9-CM codifiers. The third project encompasses two pilot studies on case-mix measurements systems and cost analysis framework. Through the fourth project concepts, methods and tools for Total Quality Management are developed, setting up specific working groups on clinical and organizational indicators for hospitals and primary health care.

Delivery of Health Care↗
PubMed1991

Antigen shedding vs. development of natural suppressor cells as mechanism of tumor escape in mice bearing Ehrlich tumor.

C57BL/6J mice immunized with devitalized Ehrlich tumor (ET) cells produce high serum levels of IgM antibodies to ET cell-surface carbohydrates that are critical in the observed resistance against this tumor. However, this response is not found in ET-bearing mice at any stage of tumor development. Since previous studies had shown splenic natural suppressor (NS) cells in ET-bearers, their role in such IgM impairment was assessed. Here we show that tumor-bearers' spleen cells (TBSC) are unable to produce IgM in vitro in response to LPS, due to the presence of NS cells. Nevertheless, TBSC do produce IgM antibodies to ET cell-surface carbohydrates in increasing amounts as the tumor progresses. Yet these antibodies are not detected in sera of ET-bearers and are greatly decreased in immunized mice with a growing tumor. Moreover, increasing amounts of circulating carbohydrates, able to absorb most specific IgM, are found in ET-bearing sera associated with a large molecular size structure(s). These carbohydrates are also found in ET cell-culture supernatants and cell-free ascites fluid derived from this tumor, indicating their tumor origin. Taken together, our results indicate that lack of specific IgM antibodies in ET-bearing mice is not due to faulty production, but to in vivo absorption by carbohydrates shed from ET cells in increasing amounts as the tumor progresses. Thus, NS cells are unable to suppress this IgM production in vivo, despite the strong suppressor activity they show for many responses in vitro.

Animals↗
PubMed1991

One-step purification of the major rainbow trout immunoglobulin.

Salmonid immunoglobulin purification has been hampered by time-consuming, labour-intensive, conventional chromatographic procedures. In this report we describe the use of immunoaffinity chromatography for the purification of immunoglobulins from trout serum in a single step. An anti-heavy chain monoclonal antibody (1G7) which reacts with more than 85% of total trout immunoglobulins was used to purify the trout immunoglobulin. The purity achieved was higher than 95%, and the immunoglobulins recovered were fully immunogenic. This method served equally well in isolating immunoglobulins from the sera of other salmonids (coho salmon and chinook salmon). The procedure should be useful in the standardization of salmonid immunoglobulin reagents.

Animals↗
PubMed1991

An alternatively spliced c-mil/raf mRNA is predominantly expressed in chicken muscular tissues and conserved among vertebrate species.

The chicken c-mil gene produces two mRNA species generated by an alternative splicing mechanism. These two transcripts differ at least by the presence or absence of a 60 nucleotide exon (E7a) localized at the splice junction of c-mil exons 7 and 8. By using RNAase protection assays, we have analysed the pattern of expression of these two mRNA species in several chicken tissues. Here we report that the two c-mil mRNAs are differentially expressed in chicken tissues: the mRNA lacking E7a is detected in all tissues tested, while the mRNA containing E7a is detected only in the skeletal muscle, heart and brain. Sequences homologous to E7a have also been detected in DNAs from quail, mouse and human cells and their sequencing revealed that the alternative E7a is structurally preserved in these species. By PCR analyses performed on RNAs extracted from muscular tissues of these species, we also show that the alternative splicing mechanism described in chicken also occurs in these species.

Amino Acid Sequence↗
PubMed1991

[Balance in deaf children].

The author notes the absence of vertigo in deaf children but, on the other hand, noted 7% instability in a group of 176 children. The electronystagmogram is modified rather often; 30 out of 68 cases of clear hypoexcitability or inexcitability. Dysrhythmia is frequent. Finally, the author emphasizes the relevance of associating posturography for exploring balance in deaf children.

Child↗