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J Lloreta

Publications and source records attributed to J Lloreta.

At least 19 recordsLinked to original sources
PubMed2006

Expression of androgen, oestrogen alpha and beta, and progesterone receptors in the canine prostate: differences between normal, inflamed, hyperplastic and neoplastic glands.

The expression of receptor for androgen (AR), oestrogen alpha and beta (ERalpha and ERbeta) and progesterone (PR) was examined immunohistochemically in canine prostate specimens (normal, hyperplastic, inflamed [prostatitis] or neoplastic). AR immunolabelling was seen in 100% of epithelial cells of normal and hyperplastic tissue, the corresponding figures for inflamed and carcinomatous tissue being 74% and 65%, respectively. ERalpha labelling was seen in 85% of epithelial cells in normal prostate glands, the corresponding figures for hyperplastic, inflamed and neoplastic glands being 35%, 22% and 12%, respectively. ERbeta labelling was seen in 85% of epithelial cells of normal glands and in about 70% of such cells in glands showing pathological changes. On the other hand, PR expression (weak) in normal glands was observed in fewer epithelial cells (44%) than in hyperplastic (70%), inflamed (62%) or neoplastic (64%) glands.

Animals↗
PubMed2005

Erythrokeratoderma variabilis-like ichthyosis in Chanarin-Dorfman syndrome.

Neutral lipid storage disease (Chanarin-Dorfman syndrome) is an autosomal recessive metabolic disorder associated with congenital ichthyosis and a multisystemic accumulation of neutral lipids (lipid droplets) in various types of cells. The clinical presentation has been reported to correspond to that of nonbullous congenital ichthyosiform erythroderma. We report a 4-year-old boy presenting a generalized ichthyosiform disorder manifested by migrating scaly plaques alternating with areas of normal-looking skin, showing erythematous borders with sharp margins, clinically suggestive of erythrokeratoderma variabilis (EKV). A peripheral blood smear revealed cytoplasmic vacuoles in most granulocytes. Genetic studies from the patient and his parents revealed that the patient carried two different and novel mutations of the ABHD5 gene: a nonsense mutation in exon 6 (transmitted by the father) and an insertion/deletion in exon 4 (transmitted by the mother). Our observation demonstrates the clinical heterogeneity of the ichthyosiform dermatoses observed in Chanarin-Dorfman syndrome and widens the clinical range of conditions presenting migrating scaly plaques mimicking EKV.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗
PubMed2003

Alendronate and etidronate do not regulate interleukin 6 and 11 synthesis in normal human osteoblasts in culture.

Bisphosphonates exert a potent inhibitory effect on bone resorption. Several studies have been performed, with contradictory results, to ascertain whether the effect of bisphosphonates on osteoclasts could be produced, at least in part, by modulation of the synthesis of resorption-promoting factors by osteoblasts. The aim of this study was to evaluate the effect of etidronate (10-4-10-9 M) and alendronate (10-7-10-12 M) on the production of IL-6 and IL-11 using human osteoblast cultures. Cytokines were quantified by ELISA, and mRNA expression was tested. Treatment with alendronate and etidronate had no effect on the synthesis of IL-6 or IL-11, and IL-6 and IL-11 mRNA levels. These results were obtained both in nonstimulated cultures and in cultures stimulated by means of TNF-a, IL-1b, and TNF-a+IL-1b, with or without FCS. In conclusion, a possible indirect osteoclast-mediated effect of alendronate and etidronate on bone resorption would not be exerted through reduction in osteoblastic synthesis of IL-6 and IL-11.

Aged↗
PubMed2002

[Fiber-optic bronchoscopic biopsy of bronchial smooth muscle. Efficacy of the technique in individuals with normal lung function and patients with COPD].

BACKGROUND AND OBJECTIVES: The epithelium and airway smooth muscles of patients with chronic obstructive pulmonary disease (COPD) or bronchial asthma undergo certain structural changes that are probably related to increased expression of inflammatory molecules and cell growth factors. Studying the relation between disease and changes in bronchial smooth muscle is difficult if investigation is restricted to samples from autopsies or thoracotomies. This study was designed to evaluate the probability of obtaining bronchial smooth muscle by endoscopic bronchial biopsy in patients with COPD and from individuals with normal lung function, the relation of disease to bronchial epithelial histology, and the potential usefulness of studying airway muscle remodeling events. METHODS: Forty-two patients undergoing diagnostic fiberoptic bronchoscopy were enrolled. Bronchial biopsies were taken systematically from the lobar and segmental dividing ridges. The epithelial structure was analyzed by conventional histology. The smooth muscle was identified by immunohistochemistry (anti-desmin antibody assay) and Western-blot analysis (anti-desmin, actin and myosin antibodies). RESULTS: Sixty-nine percent of the biopsies contained bronchial smooth muscle. The probability of obtaining smooth muscle was higher in segmental than in lobar biopsies (72 vs 30%, p < 0.05). This probability was unrelated to the presence of COPD or to signs of epithelial inflammation. The fragments allowed us to use electrophoresis to identify protein structures (myosin, actin, desmin) involved in muscle remodeling processes. CONCLUSIONS: Endoscopic biopsy of the bronchi allows us to obtain bronchial smooth muscle samples in a large percentage of patients, particularly when performed on segmental bronchi. The technique may be useful for future studies examining the processes of airway smooth muscle remodeling.

Aged↗
PubMed2002

Procion orange tracer dye technique vs. identification of intrafibrillar fibronectin in the assessment of sarcolemmal damage.

BACKGROUND: The use of Procion orange dye (POD) is one of the most widely accepted techniques to assess sarcolemmal damage. This phenomenon has been related to functional adaptation in skeletal muscles. The POD method includes intravenous injection of this colorant in vivo, enabling its identification inside those fibres with membrane leaks (fluorescence). However, the safety of the use of POD has not been proven. AIM: This study was designed to compare POD with a safer alternative, involving the identification of intracellular fibronectin using specific antibodies. METHOD: Eight Swiss mice were submitted to electrical stimulation of the lower limbs at different frequencies (10-80 Hz). Subsequently, the POD solution was infused, and samples from the vastus medialis muscle were obtained 24 h later. Samples were processed and serial sections were analysed using immunohistochemistry (monoclonal antibodies against fibronectin) and epifluorescence microscopy. RESULTS: Ninety-eight per cent of the fibres were equally classified by both techniques, which in addition showed good correlation (percentages of damaged fibres, r = 0.998, P < 0.001) and concordance (R1 = 0.82) in quantitative terms. CONCLUSIONS: Although the two techniques compared here are based on different principles, both are comparable in assessing sarcolemmal damage. This would facilitate comparisons between human and experimental studies. In addition, the fibronectin technique appears to be a suitable alternative for long-term studies including repeated biopsies.

Animals↗
PubMed2001

Injury of the human diaphragm associated with exertion and chronic obstructive pulmonary disease.

Injury of the diaphragm may have clinical relevance having been reported in cases of sudden infant death syndrome or fatal asthma. However, examination of diaphragm injury after acute inspiratory loading has not been reported. The purpose of this study was to determine whether an acute inspiratory overload induces injury of the human diaphragm and to determine if diaphragm from chronic obstructive pulmonary disease (COPD) is more susceptible to injury. Eighteen patients with COPD and 11 control patients with normal pulmonary function (62 +/- 10 yr) undergoing thoracotomy or laparotomy were studied. A threshold inspiratory loading test was performed prior to surgery in a subset of seven patients with COPD and five control patients. Samples of the costal diaphragm were obtained during surgery and processed for electron microscopy analysis. Signs of sarcomere disruption were found in all diaphragm samples. The range of values of sarcomere disruption was wide (density: 2-45 abnormal areas/100 microm(2); area fractions: 1.3-17.3%), significantly higher in diaphragm from patients with COPD (p < 0.05) and with the greatest injury after inspiratory loading. We conclude that sarcomere disruption is common in the human diaphragm, is more evident in patients with COPD, and is higher after inspiratory loading, especially in the diaphragm of those with COPD.

Aged↗
PubMed2001

Renal cell carcinoma with syncytial giant cell component.

We report a case of clear cell renal cell carcinoma in which a prominent multinucleated giant cell component was intermingled with clear, granular, and spindle cells. Histological, ultrastructural, cytometric, and cytogenetic features of giant cells were similar to those of mononucleated cells in the tumor, and therefore they were not from stromal or osteoclast derivation. These giant cells had homogeneous, finely granular, abundant cytoplasm, often with scalloped cell borders, and contained from 5 to more than 50 nuclei, all of them very similar in size and shape, with prominent central nucleoli. Occasionally, surrounding inflammatory cells were also engulfed in the cytoplasm. This syncytial appearance was more similar to that of some giant cell carcinomas from the lung than to the pleomorphic giant cells often encountered in high grade renal cell tumors. Although the patient is alive and free of disease 6 years after diagnosis, a longer follow-up will be required to assess the potential prognostic influence of this peculiar histological appearance.

Carcinoma, Giant Cell↗
PubMed2001

Fine-needle aspiration of chromophobe renal-cell carcinoma metastatic to the thyroid gland.

Chromophobe renal cell carcinoma is an unusual variant of renal carcinoma that has less aggressive behavior than clear cell carcinomas. There are few documented cases of metastases, none of which occurred in the thyroid gland. A case is presented of chromophobe renal cell carcinoma metastatic to the thyroid eight years after right nephrectomy, suspected by FNA-biopsy and confirmed histologically. Although metastases of chromophobe renal cell carcinoma are rare, they may also present in thyroid, even many years after primary tumor diagnosis, just like clear cell carcinomas. Even though the FNA cytology of chromophobe renal cell carcinoma has distinctive features, in the context of the thyroid, it can be mistaken for a primary tumor of that organ. In our case, the history of a previous renal tumor was essential in suggesting a metastatic lesion, and histologic and ultrastructural features allowed its precise identification.

Aged↗
PubMed2001

Bone metaplasia in a case of bilateral renal cell carcinoma.

We present a case of synchronous, bilateral renal cell carcinoma with osseous metaplasia. In renal cell carcinoma, bone can originate through two different processes: osseous differentiation or osseous metaplasia. The case we report here represents the second process. We discuss pathological differential diagnosis and prognosis of the infrequent tumor.

Aged↗
PubMed2001

Mucins as differentiation markers in bronchial epithelium. Squamous cell carcinoma and adenocarcinoma display similar expression patterns.

UNLABELLED: Highly glycosylated apomucins are important to maintain the viscoelastic properties of the mucus. Changes in their expression are frequently associated with inflammatory and neoplastic conditions. We analyzed the expression of apomucins in normal respiratory tract (n = 8) and compared it with distal, peritumoral, and tumoral epithelia from patients with squamous cell carcinoma (n = 20), adenocarcinoma (n = 13), and small cell carcinoma (n = 12). Squamous metaplasia (n = 16) was also analyzed. MUC1, MUC2, MUC4, MUC5AC, MUC6, and MUC8 apomucins were detected by immunohistochemistry, and mucin transcripts by in situ hybridization and reverse transcriptase polymerase chain reaction. Bronchial epithelium from normal individuals and distal epithelium from cancer patients showed a similar expression pattern: MUC1, MUC4, and MUC8 were always present, MUC2 and MUC5AC showed more variability, and MUC6 was focally detected. MUC5AC was downregulated in peritumoral epithelium and in squamous metaplasia, and MUC6 was upregulated in peritumoral epithelium. A reduced expression of MUC4, MUC5AC, and MUC8 was observed in non-small cell carcinomas, regardless of their histologic subtype. In small cell tumors, only MUC1 was consistently expressed. CONCLUSIONS: (1) peritumoral epithelium and squamous metaplasia show an abnormal pattern of mucin expression; (2) squamous cell carcinomas and adenocarcinomas display a similar pattern of mucin gene expression, supporting the concept of a common cellular origin.

Adenocarcinoma↗
PubMed2000

Reactive vascular lesion of nasal septum simulating angiosarcoma in a cocaine abuser.

We report the case of an exuberant ulcerative angiomatoid nasal lesion in a cocaine abuser. The lesion was made up of polymorphous endothelial cells with occasional mitoses, arranged in a lobular pattern with infiltrative-looking areas. There were extensive areas of thrombosis with focal recanalization. Intravascular proliferation was not observed. The clinical, radiological, and histological features suggested hemangiosarcoma as the main differential diagnosis, but the lobular architecture of the lesion and the widespread thrombosis favoured the diagnosis of a benign reactive process.

Adult↗
PubMed2000

Malignant pigmented clear cell epithelioid tumor of the kidney: clear cell ("sugar") tumor versus malignant melanoma.

A 73-year-old woman presented with an hemorrhagic kidney tumor initially interpreted as a renal cell carcinoma (RCC). A retroperitoneal recurrence infiltrating the duodenal wall was made up of clear cells, some of which contained Fontana-Masson positive pigment, immunopositive for HMB-45, S-100 protein, actin, and vimentin. The same immunohistochemical profile was retrospectively reproduced in the kidney tumor, where melanosomes were also found ultrastructurally. Lipomatous differentiation was not observed. There was no history of malignant melanoma (MM), or stigmata of tuberous sclerosis. The patient died of disease 5 years after the initial diagnosis. This neoplasm can be considered as a malignant, pigmented, clear-cell epithelioid variant of angiomyolipoma, or "sugar" tumor of the kidney, with the peculiarity of having a previously unreported component of pigmented cells visible on light microscopy. This finding raises the possibility that the exceptional cases of MM reported in renal parenchyma may be pigmented variants of epithelioid angiomyolipoma rather than true MM.

Aged↗
PubMed1999

Independent regulation of adherens and tight junctions by tyrosine phosphorylation in Caco-2 cells.

To study the role of tyrosine phosphorylation in the control of intercellular adhesion of intestinal cells, we have generated several clones of Caco-2 cells that express high levels of pp60v-src only after addition of butyrate. Expression of this oncogene in cells 5 days after confluence induced beta-catenin and p120-ctn tyrosine phosphorylation, redistribution of E-cadherin to the cytosol and disassembly of adherens junctions. However, tight junctions of Caco-2 cells at 5 days after confluence were not altered by expression of pp60v-src. Similar results were obtained when Caco-2 cells were incubated with phosphotyrosine phosphatase inhibitor orthovanadate. Although addition of this compound to postconfluent cells disrupt adherens junctions, tight junctions remain unaltered, as determined measuring monolayer permeability to mannitol or hyperphosphorylation of Triton-insoluble occludin. Modifications in tight junction permeability of Caco-2 were only observed at high concentrations of orthovanadate (1 mM). Interestingly, this tyrosine phosphorylation-refractory state was achieved after confluence since early postconfluent cells (day 2) showed a limited but significant response to low doses of orthovanadate. These results suggest that tight junctions of differentiated Caco-2 cells are uncoupled from adherens junctions and are insensitive to regulation by tyrosine phosphorylation.

Caco-2 Cells↗
PubMed1999

In vitro synthesis of type I collagen: quantification of carboxyterminal propeptide of procollagen type I versus tritiated proline incorporation.

Radioimmunoassay of the carboxyterminal propeptide of human type I procollagen has been recently introduced to measure in vitro synthesis of type I collagen by osteoblasts and fibroblasts. However, it has not been assessed whether the equivalent results are obtained with this new assay and with tritiated proline incorporation to collagen protein. To this purpose, both methods were used to quantify synthesis of type I collagen in normal human osteoblast cultures to which fetal calf serum and human serum were added in order to stimulate protein synthesis. A positive correlation in the results obtained by both methods was obtained (r = 0.95, P = 0.0001). Given the technical advantages of detection of levels to carboxyterminal propeptide of type I procollagen, we consider that this is the technique of choice for the quantification of in vitro synthesis of type I collagen by normal human osteoblasts.

Aged↗
PubMed1999

[Capillary density and respiratory function in the external intercostal muscle].

UNLABELLED: Changes in lung function have been related to adaptive structural modifications in respiratory muscles. OBJECTIVE: To evaluate the capillary density (Dcap) of the external intercostal muscle in patients with chronic obstructive pulmonary disease (COPD), and its possible relation to respiratory function. METHODS: Forty-two individuals (61 +/- 9 years old) underwent conventional lung function testing and evaluation of respiratory muscles (maximum pressures at rest and a tolerance test using Martyn's technique). The sample included 10 subjects with normal lung function and 32 COPD patients (FEV1 between 13 and 78% of reference), in stable phase and with no respiratory insufficiency (PaO2 > 60 mmHg). A local biopsy of the external intercostal muscle was taken from all subjects at the fifth intercostal space (anterior axillary [correction of axile]) on the non-dominant side. The sample was processed for morphometry and fiber typing with ATPase staining and for quantifying capillarity with Gomori's trichrome staining. RESULTS: The mean diameter was 61 +/- 10 micrograms, with type I fibers predominating (56 +/- 11%). Dcap was 2.8 +/- 0.6 capillaries/fiber (equivalent to 1.02 +/- 0.37 capillaries/mm2 of fibrillary surface). The number of capillaries/fiber was significantly higher in patients with severe COPD (FEV1 < 50% ref) than in controls (3.0 +/- 0.6 versus 2.3 +/- 0.5, p < 0.01) and was inversely related to FEV1 (r = -0.395, p < 0.01). Muscle capillarity was unrelated to other function variables, including markers of respiratory muscle function and gas exchange. CONCLUSION: The structural remodelling of external intercostal muscles in COPD patients also includes an increase in density of interfibrillary capillaries. This increase is proportional to the severity of obstruction and probably reflects an adaptive phenomenon.

Aged↗
PubMed1999

DNA image cytometry. An alternative method in osteoblast proliferation assays.

OBJECTIVE: To assess whether DNA image cytometry can be used as an alternative method to tritiated thymidine uptake quantification in osteoblast proliferation assays. STUD DESIGN: Proliferation of normal human osteoblasts incubated with normal human serum at 0%, 2.5%, 5%, 10%, 20% and 40% was quantified by tritiated thymidine uptake quantification and DNA image cytometry. RESULTS: Tritiated thymidine uptake quantification showed that normal human serum stimulated the proliferation of normal human osteoblasts and that the degree of stimulation was directly related to the concentration of serum in the culture medium. Similar results were obtained when the DNA image cytometry assay was used. A highly significant linear relationship between the ranks of both methods was found (Spearman's r = 1.00, P = .0253). CONCLUSION: DNA image cytometry may be a valuable alternative when the use of radioactive material is not desired and/or subsequent morphologic or immunocytochemical characterization of cells under study is required.

Aged↗