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Biomedical subjects

J Corominas

Publications and source records attributed to J Corominas.

17 recordsLinked to original sources
PubMed1998

Structure and function relationships of the respiratory muscles.

Potential relationships between the structure of the diaphragm and external intercostals and several indices of respiratory muscle function, lung function and nutrition in 27 patients (61+/-10 yrs of age) subjected to thoracotomy as a result of a lung neoplasm have been investigated. Prior to surgery the nutritional status of the patients was assessed and lung function (spirometry, lung volumes, transfer factor of the lungs for carbon monoxide, arterial blood gases) and respiratory muscle function (maximal inspiratory pressure (MIP) and diaphragmatic function were measured). Biopsies of the diaphragm (and external intercostals) were obtained during surgery. On average, patients showed mild airflow limitation (forced expiratory volume in one second (FEV1), 70+/-14% of predicted value, FEV1/forced vital capacity (FVC), 70+/-9%) with some air trapping (residual volume (RV), 139+/-50% pred) and normal gas exchange (arterial oxygen tension (Pa,O2), 11.3+/-1.33 kPa (85+/-10 mmHg)) and arterial carbon dioxide tension (Pa,CO2) 5.4+/-0.5 kPa (40.6+/-4 mmHg). MIP was 77+/-25% pred; maximal transdiaphragmatic pressure was 90+/-27 cmH2O. Most morphometric measurements of the diaphragm and external intercostals were within the range of values reported previously in other skeletal muscles. The size of the fibres of these two respiratory muscles was positively related (p<0.05) to MIP (% pred). There were no significant relationships between the structure of both muscles and nutritional status or any index of lung function. In conclusion, in the population studied, the fibre size of the diaphragm and external intercostals appears to relate to their ability to generate force.

Diaphragm↗
PubMed1997

Immunohistochemistry of minor salivary gland biopsy specimens from patients with Sjögren's syndrome with and without hepatitis C virus infection.

OBJECTIVES: To characterise phenotypically the minor salivary glands of patients with clinical and histological features of Sjögren's syndrome (SS) infected with hepatitis C virus (HCV). PATIENTS AND METHODS: 75 consecutive patients with SS (31 primary SS, 44 secondary SS) diagnosed by preliminary European classification criteria. The presence of anti-HCV antibodies was detected by commercial third generation ELISA and by a second generation immunoblot assay. Presence of HCV genome in serum was determined by polymerase chain reaction analysis. Expression of CD3, CD4, CD8, CD20, HLA-DR, and CD25 molecules in lymphocytic and epithelial cells on minor salivary glands was detected by immunohistochemical assays. Expression of interferon gamma and interleukin 4 cytokines was determined by in situ hybridisation. RESULTS: Six of 31 primary SS (19%) and one of 44 secondary SS (2%) serum samples were positive for anti-HCV by ELISA. Three samples were positive, three indeterminate, and one sample corresponding to a secondary SS patient was negative by immunoblot. The three immunoblot positive serum samples were also HCV-RNA positive by PCR assay. The study of lymphocytic cells in the diffuse infiltrate of minor salivary glands showed a predominance of the CD3 lymphocytic population. A predominance of CD4 over CD8 T cells (ratio 2:1) was observed in HCV and non-HCV infected patients. The analysis of the lymphocytic focus showed that the HCV infected patients had a predominance of CD20 positive cells. Activation molecules (CD-25 and HLA-DR) were expressed in HCV and non-HCV infected patients in lymphocytic and epithelial cells, however epithelial cell expression of CD25 was low in HCV infected patients. As expected, a pronounced Th1 response was observed in the lymphocytic foci of HCV patients. CONCLUSIONS: HCV infected patients may develop an autoimmune sialadenitis, similar to that described in primary SS.

Adult↗
PubMed1997

High prevalence of subclinical Sjögren's syndrome features in patients with autoimmune thyroid disease.

OBJECTIVE: To determine the prevalence of keratoconjunctivitis sicca and xerostomia related to Sjögren's syndrome (SS) in asymptomatic patients with diagnosed autoimmune thyroid diseases (AITD); and to investigate whether the immunopathologies of sialadenitis observed in AITD associated SS and primary SS are similar. METHODS: One hundred seventy-six patients diagnosed with AITD (88 with Graves' disease, 40 Hashimoto's thyroiditis, 48 primary myxedema) were tested for keratoconjunctivitis sicca (Schirmer's test and rose bengal staining) and for xerostomia (salivary scintigraphy and labial salivary gland biopsy). Immunohistopathological studies were performed on cryostat sections of bucal mucosa biopsies using antibodies to CD3, CD4, CD8, CD20, CD14, CD25, LFA-1, ICAM-3 HLA class II, tumor necrosis factor-alpha, interleukin 1, and interferon-gamma. RESULTS: Nineteen of 52 (37%) patients with AITD fulfilled the criteria for xerostomia and 39/170 (23%) for keratoconjunctivitis sicca. Features of SS were diagnosed in 43 of 176 (24%) patients with AITD, with similar prevalence in Graves' (20%). Hashimoto's thyroiditis (27%), and primary myxedema (29%). In AITD associated SS, infiltrating lymphocytes were mainly CD3+ T lymphocytes, with a CD4/CD8 ratio of 2:1. In most patients infiltrating lymphocytes expressed activation markers, HLA class II molecules, and interleukin 2 receptor (CD25). In some patients HLA class II was inappropriately expressed in the epithelial gland cells. CONCLUSION: The finding that a third of patients with AITD have SS features confirms that AITD and SS are mutually associated. Together with the similarity of immunopathology of sialadenitis in AITD associated SS in primary SS, this supports the theory that SS and AITD are 2 autoimmune diseases closely related pathogenetically.

Adolescent↗
PubMed1995

[Muscle relaxants in the morphometric study of the respiratory muscles in human beings].

The morphological examination of respiratory muscle can be affected by muscular contraction following biopsy. Most morphometric studies of respiratory muscles, however, have been carried out without taking into account this factor, the effect of which can be reduced by using relaxants when taking samples. Objective. To examine the effect of using a relaxant in the morphometric analysis of muscle fibers. We examined 31 muscle samples from 7 patients. Immediately after removal, each pipe was divided in half. One was placed in an isotonic physiological solution and the other in a solution of curare 0.02%. Later, both samples were processed for morphometric study with ATP-ase, NADTH and PAS tincture. Morphological data recorded for the different types of fibers included measurement of minimum diameter (Dmin), atrophy and hypertrophy indices (AI and HI) and heterogeneity of distribution (SDDmin). The Dmin was smaller in fibers transported in a curare solution than in those transported in physiological solution (67 +/- 2 microns vs. 71 +/- microns, p < 0.05). The same was true of SDDmin (13 +/- 3 vs. 12 +/- 3, p < 0.05), HI (300 +/- 88 vs. 457 +/- 107, p < 0.05). Likewise, we found a similar direct correlation between size of fibers processed with physiological solution and those processed in curare (Dmin, r = 0.731, p < 0.001; HI, r = 0.827, p < 0.001; SDDmin, r = 0.636, p < 0.0001). The use of relaxants in processing muscle samples prevents contraction and should be used systematically in the morphological analysis of muscle fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1995

Interleukin-2 receptor expression in salivary glands of patients with Sjögren's syndrome.

OBJECTIVE: To study interleukin-2 receptor (IL-2R) expression in lymphocytic and epithelial cells in salivary glands of patients with Sjögren's syndrome (SS). METHODS: Minor salivary glands of 29 patients with primary SS, 28 with secondary SS, 19 with autoimmune diseases without SS, and 17 controls were studied using immunohistochemical techniques. Sections were analyzed with 3 different antibodies reacting with CD25 molecule. RESULTS: The presence of IL-2R (CD25) was observed in minor salivary gland lymphocytic infiltrate in 26 (89.6%) primary SS, 24 (85.7%) secondary SS, and 16 (84%) autoimmune diseases without SS. CD25 antibody was expressed in epithelial cells in 12 (41%) patients with primary SS and 11 (39%) with secondary SS, but was absent in the group of autoimmune diseases without SS and the control group. CONCLUSION: The lymphocytic infiltrate of minor salivary gland expressed IL-2R in patients with primary SS, secondary SS and autoimmune diseases without SS. IL-2R expression in epithelial cells was only present in patients with primary or secondary SS.

Antibodies, Monoclonal↗
PubMed1993

The gene PPG encodes a novel yeast protein phosphatase involved in glycogen accumulation.

Degenerate oligonucleotides were used to selectively amplify yeast genomic sequences related to Ser/Thr protein phosphatases. Among the sequences obtained, clone ST4-2 was found to code for a novel sequence related to previously known phosphatases. A size-selected yeast genomic library was constructed and screened using clone ST4-2 as probe, and one positive clone, named PPG, was isolated. DNA sequencing of a 1.8-kilobase pair fragment of this clone revealed an open reading frame of 1104 base pairs which codes for a 368-amino acid protein. On the basis of its amino acid sequence, the product of gene PPG would be an acidic protein, structurally more related to type 2A than to type 1 or 2B phosphatases, and is characterized by an extension of about 50 amino acids at the carboxyl terminus. The gene, which is located in chromosome XIV, is expressed as a 1.3-kilobase mRNA and is not essential for growth. Haploid mutants carrying a disrupted copy of the gene were able to grow in glucose as well as in other carbon sources, but they accumulated less glycogen than the wild type strain. However, the state of activation of glycogen synthase was essentially identical in wild type and mutant cells. The finding that, in early exponential phase, mutant cells contain higher levels of glycogen phosphorylase a, in addition to a lower amount of total glycogen synthase activity observed in medium-late exponential phase, could account for the difference found in glycogen accumulation.

Amino Acid Sequence↗
PubMed1992

Glycogen metabolism in a Saccharomyces cerevisiae phosphoglucose isomerase (pgil) disruption mutant.

Disruption of the gene pgil of Saccharomyces cerevisiae, which codes for phosphoglucose isomerase, results in a dramatic increase in the amount of intracellular glycogen in early exponential cultures. The level of glucose 6-phosphate was much higher in mutant than in wild-type cells. Phosphorylase a activity and the state of activation of glycogen synthase were also investigated. Phosphorylase a activity was rather low along the culture in wild-type cells, whereas it was consistently higher in mutants. Glycogen synthase was mostly in the active form in early-medium exponential cultures in wild-type cells whereas the activation state of this enzyme in mutant cells, although lower at the earlier steps of the culture, did not differ from wild-type cells at later stages. The fact that the intracellular levels of UDP-glucose are markedly increased in mutant cells suggest that the observed accumulation of glycogen results from a rise in substrate availability rather than from the activation of the enzyme responsible for the synthesis of the polysaccharide.

Enzyme Activation↗
PubMed1991

[Eosinophilic cystitis as a special form of response to mitomycin C. Analysis and comments on our cases].

We analyzed 29 cases of eosinophilic cystitis in a group of 80 patients with lower urothelial carcinoma who had been treated with mitomycin-C. Only 6 cases (20.7%) had presented symptoms and signs compatible with acute cystitis. The remaining patients had been diagnosed histopathologically by routine follow-up bladder biopsy. Urine cytology revealed abundant eosinophils in 58.6% of the patients with eosinophilic cystitis while urine culture was negative for all patients. No patient had a previous history of allergy or asthma. We discuss the possible etiopathogenic mechanisms of this rare nosologic entity, the relationship to the immune system and the role of the foregoing in the capacity to control urothelial carcinoma locally.

Administration, Intravesical↗
PubMed1991

[Mitochondrial myopathy and leukoencephalopathy in twins of different sexes].

Two 30-year old twins, one male, the other female, were followed up for 20 years for predominantly proximal muscular deficit without increase of muscle enzymes. The lactic acid level was elevated at rest and further increased during exercise. Muscle biopsy revealed mitochondrial abnormalities. Encephalopathy was also present. The female patient had been treated, at the age of 10 years, for myoclonic attacks which regressed when she was over 18 years. None of the two patients had dementia. CT and MRI showed very extensive and symmetrical lesions of the white matter which did not involve the basal ganglia. These two cases are interesting on three scores: (1) clinically, the woman exhibited symptoms of the MELAS syndrome (without cerebral vascular accidents) and symptoms of the MERRF syndrome, which suggests the existence of borderline cases; (2) genetically, our cases were in favour of a so-called "maternal" heredity (boys are affected in all cases): here both sexes were involved but the phenotype varied; (3) biochemically, we found no enzyme activity deficit likely to explain the clinical features. The significance of a selective increase of cytochrome c oxidase in both mother and daughter is unclear.

Adult↗