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Biomedical subjects

C Soler

Publications and source records attributed to C Soler.

At least 73 records · Page 4Linked to original sources
PubMed1997

The role of technetium-99m sestamibi single photon emission tomography in the follow-up of malignant melanoma and the detection of lymph node metastases.

In the follow-up of patients with malignant melanoma treated by surgical resection of the cutaneous tumour, it is important to achieve early detection of possible lymph node metastasis. In many cases, clinical examination alone will not be sufficient. In our study, single-photon emission tomography (SPET) with technetium-99m sestamibi (MIBI) was used in the assessment of 30 patients with previously resected malignant melanoma when the clinical examination raised the suspicion of lymph node metastasis. Using MIBI, 16 out of 17 lymph node metastases were detected and confirmed by histology. No false-positive results were obtained during this prospective study. It is concluded that MIBI scintigraphy may be useful in the early detection of lymph node metastases of malignant melanomas. If our preliminary results are confirmed, early detection of lymph node metastasis of previously resected malignant melanoma by 99mTc-MIBI scintigraphy may have a significant impact on the management of these patients.

Evaluation Studies as Topic↗
PubMed1997

Prevalence and clinical significance of IgG isotype anti-beta 2-glycoprotein I antibodies in antiphospholipid syndrome: a comparative study with anticardiolipin antibodies.

To investigate the prevalence, significance, and specificity of IgG isotype anti-beta 2-Glycoprotein I antibodies (a-beta 2-GPI) in antiphospholipid syndrome (APS), we developed an enzyme-linked immunosorbent assay (ELISA) for the detection of IgG-a-beta 2-GPI and tested sera from 61 patients with autoimmune disorders (AID), 39 patients with APS and 22 patients with systemic lupus erythematosus without APS, 139 patients with various infectious diseases (hepatitis C virus infection, human immunodeficiency virus infection, Q fever, Mediterranean spotted fever, syphilis) and 97 healthy control subjects. Using irradiated plates coated with human beta 2-GPI, we showed that in the sera of patients with AID, optical densities from the coated wells were significantly higher than those from the noncoated ones (p = 0.0001). In this assay, intra-assay and inter-assay variation coefficients ranged between 4% and 10%. Clinical evaluation showed that IgG-a-beta 2-GPI were found in 23 of 61 patients with AID but in only one patient with an infectious disease. The presence of the IgG-a-beta 2-GPI in association with APS (p = 0.005) was statistically significant with high specificity (98%) and positive predictive value (87.5%) but with low sensitivity (54%), and was significantly associated with venous thrombosis (p = 0.0025). In addition, the IgG-a-beta 2-GPI levels were highly correlated with those of anticardiolipin antibodies (aCL) (p < 0.001). In contrast to a-beta 2-GPI, aCL were found with a high prevalence (40%) in patients with infectious diseases. Because of their high specificity, anti-beta 2-GPI antibodies appear to be useful tools in the evaluation of the risk of APS. However, because of their low sensitivity, their detection needs to be associated with that of aCL.

Adolescent↗
PubMed1997

Sperm morphological abnormalities appearing in the male rabbit reproductive tract.

The role of the excurrent duct system in producing and/or eliminating morphologically abnormal spermatozoa may modify the semen parameters and interfere with sperm fertilizing capacity. To study this process, changes in the morphology of spermatozoa during their transit through the reproductive tract in sexually mature rabbits were investigated. The incidence of head, midpiece and tail abnormalities as well as of multiple defects in a single spermatozoon, and the position of the cytoplasmic droplet along the sperm midpiece were evaluated in samples from the testis, 6 regions of the epididymis and the vas deferens. Spermatozoa were characterized by rapid migration of the cytoplasmic droplet when passing from the proximal to the distal caput of the epididymis, and spermatozoa with no droplet predominated in the distal epididymis and vas deferens. In passing from the testis to the proximal caput of the epididymis, the incidence of spermatozoa with an abnormal midpiece and those with multiple defects decreased significantly. The proportion of spermatozoa with abnormal heads was also lower in the testis, but no statistically significant differences were found, whereas there was no change in the proportion of those with abnormal tails. These results indicate that there must be a mechanism for the disposal of defective spermatozoa. No evidence of spermiophagy by luminal macrophages was observed in the extracts, although a few spermatozoa exhibited signs of degeneration, suggesting, that although intraepithelial phagocytosis has not been clearly demonstrated in the nonexperimental rabbit, sperm cells may undergo a form of autolysis within the lumen of the duct.

Journal Article↗
PubMed1997

Repression mechanisms of the I-A beta gene of the major histocompatibility complex.

The mechanisms of regulation of I-A beta gene expression in the murine major histocompatibility complex by transcriptional repression are reviewed. Active and passive repression mechanisms are presented. The transcription factor PU.1 actively inhibits the expression of I-A beta through the binding to a DNA sequence near the Y box, a cis-element in the promoter necessary for transcription. This interaction probably interferes with the preinitiation complex assembly. NF-Y is a transcription factor that binds to the Y box and has two constituents: NF-YA (that binds weakly to DNA) and NF-YB (that increases the binding of NF-YA to DNA). The dbpA protein represses the expression of I-A beta by a quenching mechanism, forming a complex with NF-YA and the dbpB protein by sequestering the NF-YB protein. A similar mechanism is observed with the glucocorticoid receptor that binds to the X-box binding proteins and inhibits their interaction with the X box. These results are examples of cross-talk between proteins, which may help us to understand the regulation of I-A beta gene expression.

Animals↗
PubMed1997

[Chronic recurrent multifocal osteomyelitis. A diagnosis to be called to mind].

Chronic recurrent multifocal osteomyelitis is a rare disorder that affects children and teenagers. Clinically, it is characterized by insidious onset of local swelling and pain in several metaphyses. A symmetric, recurrent and multifocal pattern is usual. Spinal involvement is possible. Inconstant association with a cutaneous affection (palmoplantar pustulosis, acne fulminans, psoriasis), or less frequently with an inflammatory chronic gut disorder is described. Pathogenesis usually recognized is an enthesopathy. Enthesitis may progress to the osseous part of the enthese and produce an aseptic chronic osteomyelitis. Biopsy specimen with culture is certainly necessary to rule out bacterial osteomyelitis and bone tumor. It is particularly true when the bone lesion is isolated. Disease course is benign and self-limited. The clinical course is characterized by recurrences and remission occurring for 6 to 10 years. Treatment based on non steroid antiinflammatory drugs is usually effective.

Adolescent↗
PubMed1996

The transcription factor PU.1 is involved in macrophage proliferation.

PU.1 is a tissue-specific transcription factor that is expressed in cells of the hematopoietic lineage including macrophages, granulocytes, and B lymphocytes. Bone marrow-derived macrophages transfected with an antisense PU.1 expression construct or treated with antisense oligonucleotides showed a decrease in proliferation compared with controls. In contrast, bone marrow macrophages transfected with a sense PU.1 expression construct displayed enhanced macrophage colony-stimulating factor (M-CSF)-dependent proliferation. Interestingly, there was no effect of sense or antisense constructs of PU.1 on the proliferation of the M-CSF-independent cell line, suggesting that the response was M-CSF dependent. This was further supported by the finding that macrophages transfected with a sense or an antisense PU.1 construct showed, respectively, an increased or a reduced level of surface expression of receptors for M-CSF. The enhancement of proliferation seems to be selective for PU.1, since transfections with several other members of the ets family, including ets-2 and fli-1, had no effect. Various mutants of PU.1 were also tested for their ability to affect macrophage proliferation. A reduction in macrophage proliferation was found when cells were transfected with a construct in which the DNA-binding domain of PU.1 was expressed. The PEST (proline-, glutamic acid-, serine-, and threonine-rich region) sequence of the PU.1 protein, which is an important domain for protein-protein interactions in B cells, was found to have no influence on PU.1-enhanced macrophage proliferation when an expression construct containing PU.1 minus the PEST domain was transfected into bone marrow-derived macrophages. In vivo, PU.1 is phosphorylated on several serine residues. The transfection of plasmids containing PU.1 with mutations at each of five serines showed that only positions 41 and 45 are critical for enhanced macrophage proliferation. We conclude that PU.1 is necessary for the M-CSF-dependent proliferation of macrophages. One of the proliferation-relevant targets of this transcription factor could be the M-CSF receptor.

Animals↗
PubMed1996

Cloning of a Bacillus sp. BP-23 gene encoding a xylanase with high activity against aryl xylosides.

The xynB gene encoding a xylanase from the recently isolated Bacillus sp. strain BP-23 has been cloned and expressed in Escherichia coli. The enzyme produced in this host shows a molecular size of 41 kDa and a pI of 4.5. The pH and temperature at which the highest activity was found were 5.5 and 50 degrees C respectively. Crude xylanase B showed activity on xylan, aryl xylosides, xylotetraose and xylotriose, while xylobiose was not hydrolyzed by the enzyme. Xylanase B showed high specific activity on aryl xylosides, probably as a result of the transxylosidase activity detected.

Bacillus↗
PubMed1996

Urinary excretion of methylated catecholamine metabolites in a child with neuroblastoma maturing into ganglioneuroma.

Neuroblastomas are malignant tumors derived embryonically from the neural crest. Biological diagnosis relies on assay of urinary excretion of homovanillic acid (HVA), vanillylmandelic acid (VMA), and dopamine (DA). Spontaneous regression of these neoplasms has been reported by numerous investigators. The authors report the case of a child with neuroblastoma that illustrates the relationship between catecholamine metabolites and tumor maturation. At 1 month of age, this infant presented an adrenal neuroblastoma with multiple metastases (stage IV); the initial histological diagnosis based on examination of cutaneous metastases was neuroblastoma. At the age of 6 months, after chemotherapy, the primary tumor was resected; hepatic metastases were discovered at laparotomy. The histological diagnosis for all lesions was highly differentiated, mature ganglioneuroma-like tissue. The main biochemical abnormality at the time of diagnosis was an elevation in normetanephrine (NMN). HVA was only slightly increased but rose progressively during chemotherapy; it dropped back to normal levels after the sixth course. This case illustrates the potential benefits of separate assays of urinary methylated catecholamine metabolites for biochemical diagnosis and therapeutic management of neuroblastoma in addition to assays of HVA, VMA, and DA. Case findings suggest existence of a transformation process with maturation of the tumor involving enzymatic regulation and expression of MAO.

Adrenal Gland Neoplasms↗
PubMed1996

Changes in the motility patterns of spermatozoa from the rabbit epididymis as assessed by computer-aided sperm motion analysis.

Sperm maturation in the epididymis includes changes in their potential for motility that enables spermatozoa to reach the egg and penetrate its investments. The motility characteristics of spermatozoa from the testis, the epididymis, and vas deferens of the rabbit were investigated by computer-assisted sperm analysis (CASA). Various forms of motility were displayed by sperm from different regions of the epididymis released into incubation medium. Testicular sperm were motile, although nonprogressive. The maximum percentage motility was expressed by sperm in the proximal cauda epididymidis, and forward progression was developed by spermatozoa from the distal caput. Once forward progression was established, the curvilinear velocity was about the same for sperm from all regions of the tract, whereas straight-line velocity increased between the mid-corpus and cauda and paralleled the decline in lateral displacement of the head. The maintenance of motility in vitro was best maintained by sperm from the distal regions of the tract although sperm from the distal caput maintained motility better than sperm from the proximal and midcorpus regions. Analysis of the motile sperm cells revealed several types of trajectories ("irregular," "small circular," "large circular and arcs," "jagged" and "straight-line") that were analyzed by discriminant analysis using the variables generated by CASA. Accuracy of classification varied from 70% to 96%, depending on the type of track. The classification function was then applied to the changes that occurred during incubation and showed that irregular trajectories gave way to small and then large circular tracks and progressive forms as sperm matured.

Animals↗
PubMed1996

Physical mapping of repetitive DNA sequences and 5S and 18S-26S rDNA in five wild species of the genus Hordeum.

The genetic relationships between several wild species and subspecies of the genus Hordeum were assessed using fluorescence in situ hybridization (FISH). Plant material included natural populations of wild barley growing in Spain of the annual species, H. marinum ssp. marinum (2n = 14) and gussoneanum (2n = 14), and H. murinum ssp. murinum (2n = 28), and leporinum (2n = 28) and the perennial species H. bulbosum (2n = 14) and H. secalinum (2n = 28), plus the South American perennial species H. chilense (2n = 14). FISH was used to locate the chromosomal sites of two rDNA multigene families 5S and 18S-26S (pTa71 and pTa794) and three repetitive DNA sequences (pSc119.2, pAs1 and pHch950) isolated from different species and genera. The seven chromosomes of the diploid species were readily distinguished by their external morphology and hybridization patterns to pTa71, pTa794, pSc119.2 and pAs1. These DNA probes were also useful for the identification of homologous chromosomes and in differentiating these from unidentified chromosomes in the tetraploid taxa. The use of the probe pHch950 permitted intergenomic differentiation in tetraploids and supports the diphyletic origin of H. murinum and H. secalinum. The in situ experiments yielded the following conclusions: (1) differences between the sub-species marinum and gussoneanum; (2) close relationships between the subspecies murinum and leporinum; and (3) major differences in physical mapping between H. bulbosum and the remaining taxa. The genomic and phylogenetic relationships between taxa, as inferred from the results, are discussed.

Chromosome Mapping↗
PubMed1996

Serologic reactivity of a synthetic peptide from human immunodeficiency virus type 1 gp41 with sera from a Mexican population.

The reactivities of 1,172 serum samples obtained from asymptomatic human immunodeficiency virus type 1 (HIV-1)-positive and HIV-1-negative individuals residing in Mexico to a synthetic disulfide-looped peptide from the HIV-1 gp41 (amino acids 602 to 616 [IWGCSGKLICTTAVP] were examined by an enzyme-linked immunoadsorbent assay (ELISA) procedure. Antibodies to the synthetic peptide were detected in 261 of 268 serum samples from HIV-positive individuals (sensitivity, 97.4%). The peptide also reacted with 12 of 904 serum samples from control HIV-negative individuals (specificity, 98.7%). Western blots (immunoblots) of four of the seven serum samples that produced false-negative results in the ELISA showed that three of them reacted weakly with gp41 and strongly with gp120, p55, and/or p24. Potential diagnostic difficulties raised by the reported C1q binding capacity of this peptide were also evaluated: few and weak false-positive results were found among sera from patients with rheumatoid arthritis (1 of 31) and neurocysticercosis (2 of 111). In fact, strong reactivity with the peptide spotted an undetected HIV infection underlying clinical neurocysticercosis.

Amino Acid Sequence↗
PubMed1996

Thirteen cystic fibrosis patients, 12 compound heterozygous and one homozygous for the missense mutation G85E: a pancreatic sufficiency/insufficiency mutation with variable clinical presentation.

To study the severity of mutation G85E, located in the first membrane spanning domain of the CFTR gene, we studied the clinical features of 13 Spanish patients with cystic fibrosis (CF) carrying this mutation. G85E accounts for about 1% of Spanish CF alleles. One patient was homozygous G85E/G85E and the rest were compound heterozygotes for G85E and other mutations (delta F508 nine patients, delta I507 two patients, and 712-1G > T one patient). The characteristics of the pooled G85E/any mutation group were compared with those of 30 delta F508 homozygotes. Mean age at diagnosis and percentage of ideal height for age were higher in the G85E/any mutation group (4.2 (SD 4.7) v 2.4 (SD 2.3), p < 0.05, and 102.8 (SD 4.7) v 97.8 (SD 4.1), p < 0.01), both probably related to the greater prevalence of pancreatic sufficiency (70% v 0%, p < 0.01). The G85E homozygote was pancreatic sufficient. Sweat sodium levels were slightly higher, and salt loss related problems more frequent, in the G85E/any group. Two of the G85E patients died of respiratory failure aged 6 and 14 years. Striking discordance in the phenotype was observed in two pairs of sibs, one of them dizygotic twins, suggesting that factors, genetic and environmental, other than CFTR genotype are important in determining CF phenotype.

Child↗
PubMed1996

Is sperm motility maturation affected by static magnetic fields?

Kinematic parameters were evaluated in mouse epididymal extracts to monitor maturation of sperm movement in animals exposed to static magnetic fields using the Sperm-Class Analyzer computerized image analysis system. For this purpose, animals were exposed to a field of 0.7 T generated by a permanent magnet over 10 or 35 days for either 1 or 24 hr/day. The values of the motion endpoints were similar in animals used as controls and in those exposed to the nonionizing radiation, whatever the period of exposure or daily dosage. Changes in motility were observed in all groups: the percentage of total motile and progressive motile spermatozoa increased during passage through the epididymis, with major changes between the caput and corpus epididymides, and the pattern of swimming changed clearly towards more rapid and straighter trajectories. The processes of initiation of sperm motility and maturation of displacement patterns were not then affected by magnetic treatment. Moreover, it appears that sperm production is unaffected because no changes were observed in testicular or epididymal weights after exposure to static magnetic fields.

Animals↗
PubMed1996

A possible role for human papillomaviruses and c-myc, c-Ha-ras, and p53 gene alterations in malignant cutaneous lesions from renal transplant recipients.

Several years after transplantation, renal transplant recipients develop numerous cutaneous squamous cell carcinomas (SCC), in which human papillomaviruses (HPV) may be detected. Alterations in c-myc, c-Ha-ras, and p53 genes were studied in 34 SCC, in correlation with the presence of HPV. In situ hybridization (ISH) and polymerase chain reaction (PCR) showed that many SCC contained several HPV types infecting different foci of epithelial cells. Using Southern blot and ISH, c-myc and/or c-Ha-ras gene amplification was detected in 7/13 SCC tested. With PCR and oligoprobe hybridization, a GGC -> GAC mutation was found at codon 12 of c-Ha-ras gene in 1/21 SCC tested, while no mutation was detected at codon 61. Using immunohistochemistry, p53 protein expression was detected either along the basal cell layer or spotted in foci of basal cells. Our results show an abnormal distribution of HPV types in SCC from renal transplant recipients, and alterations of c-myc, c-Ha-ras, and p53 genes without any direct link with the presence of any studied HPV type. Thus, viral infection and oncogene activation may represent factors involved in the etiology of skin SCC from transplant recipients.

Base Sequence↗
PubMed1995

The early stimulation of glycolysis by epidermal growth factor in isolated rat hepatocytes is secondary to the glycogenolytic effect.

We have studied the relationship between the effect of epidermal growth factor (EGF) on glycogen metabolism and its effect on glycolysis, in rat hepatocyte suspensions. Although 10 nM glucagon or 10 microM adrenaline increased glycogen degradation by more than 120%, 10 nM EGF increased glycogenolysis by less than 20% in hepatocytes incubated in glucose-free medium. Both glucagon and adrenaline increased phosphorylase a activity by more than 130%; EGF increased this activity by about 30%. Under basal conditions, 65% of the glucosyl residues were released as free glucose and about 30% ended up as C3 molecules (lactate and pyruvate). Both glucagon and adrenaline decreased the proportion of glucosyl units that rendered glycolysis end-products (to 2% for glucagon and 6% for adrenaline) and increased the proportion that ended up as free glucose (to 94% and 88% of the glucosyl residues for glucagon and adrenaline respectively). EGF increased the production of both free glucose and lactate+pyruvate, but the proportion of glucosyl residues that ended up as free glucose or glycolysis end-products was unchanged. In glycogen-depleted hepatocytes incubated in the presence of 25 mM glucose, EGF affected neither glycogen deposition nor glycolysis. EGF increased cytosolic free Ca2+, and neomycin decreased both the Ca2+ signal and the glycogenolytic effect. In conclusion, our results indicate that the effect of EGF on glycolysis is secondary to the Ca(2+)-mediated stimulation of glycogenolysis in rat hepatocyte suspensions.

Animals↗
PubMed1995

Primary bronchogenic squamous cell carcinoma in children: report of a case and review of the literature.

The authors report a case of primary bronchogenic squamous cell carcinoma (SCC) revealed by recurrent pneumonia in an 11-year-old boy. Four years after complete surgical resection followed by external radiotherapy, the patient is currently relapse- and metastasis-free. To our knowledge, this is only the sixth pediatric case of primary bronchogenic SCC reported to date.

Carcinoma, Squamous Cell↗
PubMed1995

[Prolonged neuromuscular block after mivacurium injection].

Mivacurium, a new short acting non depolarizing neuromuscular blocker, is metabolized, as suxamethonium, by plasma cholinesterase. Therefore its duration of action is increased in patients with reduced plasma cholinesterase activity. We report a case of prolonged neuromuscular block after an i.v. bolus of mivacurium (0.20 mg.kg-1) in a 69 year-old ASA II woman with an unrecognized cholinesterase deficiency undergoing a lumbar sympathectomy for arteriopathy of the lower limbs. The duration of the block was 6 h and plasma cholinesterase concentrations were very low (540 and 610 UI.L-1), as well as the dibucaine number (16%), which suggests an homozygous enzymatic deficiency. Mechanical ventilation and sedation were continued until spontaneous return of full neuromuscular function.

Aged↗