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Biomedical subjects

J Gil

Publications and source records attributed to J Gil.

At least 91 records · Page 5Linked to original sources
PubMed2000

Identification of a new HLA-DRB4 allele (DRB4*01033) by PCR-SSP and direct sequencing.

In this report, we describe the identification of a novel DRB4*01 allele, DRB4*01033, found in two Spanish Caucasian individuals. The new allele was detected during routine HLA typing by an unusual pattern of amplification obtained by polymerase chain reaction using sequence-specific primers (PCR-SSP) that did not match with any of the previously described DRB4 alleles. In order to establish the polymorphism responsible for this pattern exons 2 and 3 of the DRB4 locus were amplified and directly sequenced. The new DRB4*01 allele is identical to DRB4*0103101 except for a single nucleotide substitution in codon 78 (TAC-->TAT). This nucleotide change does not cause an amino acid change as both triplets code for a tyrosine.

Alleles↗
PubMed2000

Prodigiosin from the supernatant of Serratia marcescens induces apoptosis in haematopoietic cancer cell lines.

The effects of supernatant from the bacterial strain Serratia marcescens 2170 (CS-2170) on the viability of different haematopoietic cancer cell lines (Jurkat, NSO, HL-60 and Ramos) and nonmalignant cells (NIH-3T3 and MDCK) was studied. We examined whether this cytotoxic effect was due to apoptosis, and we purified the molecule responsible for this effect and determined its chemical structure. Using an MTT assay we showed a rapid (4 h) decrease in the number of viable cells. This cytotoxic effect was due to apoptosis, according to the fragmentation pattern of DNA, Hoechst 33342 staining and FACS analysis of the phosphatidylserine externalization. This apoptosis was blocked by using the caspase inhibitor Z-VAD.fmk, indicating the involvement of caspases. Prodigiosin is a red pigment produced by various bacteria including S. marcescens. Using mutants of S. marcescens (OF, WF and 933) that do not synthesize prodigiosin, we further showed that prodigiosin is involved in this apoptosis. This evidence was corroborated by spectroscopic analysis of prodigiosin isolated from S. marcescens. These results indicate that prodigiosin, an immunosuppressor, induces apoptosis in haematopoietic cancer cells with no marked toxicity in nonmalignant cells, raising the possibility of its therapeutic use as an antineoplastic drug.

3T3 Cells↗
PubMed2000

Iterative thresholding for segmentation of cells from noisy images.

We introduce an iterative thresholding algorithm for the segmentation of cells from noisy cell images. The thresholding image, which is initially a constant, changes iteratively with both the previous segmentation and image local activity. Experimental results for both synthesized and real cell images are provided to demonstrate the performance of the algorithm.

Algorithms↗
PubMed2000

Subcellular distribution of pyroglutamyl-peptidase I activity in the developing rat cerebellum.

In this work we analyzed the activity of pyroglutamyl (pGlu)-peptidase I in several subcellular fractions of the rat cerebellum during its development. The aim of this study is to determine if there is a developmental redistribution of this enzyme activity and if this fact could indicate changes in the role of the enzyme as age progresses. Results show that pGlu-peptidase I is widely distributed, but not homogeneously, in all the subcellular fractions that were studied, in both soluble and particulate forms. Significantly the distribution of the enzyme changes with development. Thus, in the soluble synaptosomal fraction, the pGlu-peptidase I activity is low until PD9 and the activity increases significantly from PD9 to PD15, when it reaches adult levels. In contrast, in the cytosolic fraction, the pGlu-peptidase I activity is high from fetal day 22 to postnatal day 6, and then decreases significantly until postnatal day 90.

Animals↗
PubMed2000

Morphometric and electron microscopic analyses of the effect of gonadotropin-releasing hormone agonist treatment on arteriole size in uterine leiomyomas.

BACKGROUND: Few studies have been performed on the vascular changes in leiomyomas from patients treated with gonadotropin-releasing hormone agonists (GnRHAs). OBJECTIVE: To measure luminal diameter and wall thickness of arterioles in uterine leiomyomas using a quantitative stereologic method of analysis. DESIGN: Thirty leiomyomas from 3 study groups were used: (1) patients treated with GnRHAs (10 patient samples), (2) age-matched controls (10 patient samples), and (3) postmenopausal women (10 patient samples). Measurements of arteriolar luminal diameter and wall thickness were made using a video-based, computerized system attached to the microscope, for which a morphometric ad hoc program was written. Electron micrographs were made of random arterioles from the first 2 groups (GnRHA-treated patients and age-matched controls). SETTING: Department of Pathology, Mount Sinai School of Medicine, New York, NY. PATIENTS: A total of 30 patient samples were studied, with 3 groups comprising 10 samples each, including patients treated with GnRHAs, age-matched control patients, and postmenopausal women. RESULTS: Arterioles in myomas from patients treated with GnRHAs had slightly larger luminal diameters and significantly thicker walls than age-matched controls and resembled arterioles from postmenopausal women. The thickening was due to smooth muscle cell hyperplasia in the muscularis media. CONCLUSIONS: Treatment with GnRHAs causes a thickening of the walls of intramyomatous arterioles, which resemble those of postmenopausal women. This thickening may play a role in the decreased flow of blood reported in GnRHA treatment.

Adult↗
PubMed2000

Inhibition of cyclooxygenase-2 decreases DNA synthesis induced by platelet-derived growth factor in Swiss 3T3 fibroblasts.

NS-398 [N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide], a selective inhibitor of cyclooxygenase-2 (COX-2), inhibited proliferation induced by platelet-derived growth factor (PDGF) in Swiss 3T3 fibroblasts. The effect of NS-398 was found to be concentration-dependent. The half-maximal effect occurred at approximately 0.1 microM. NS-398 decreased mitogenesis at subsaturating PDGF concentrations and the inhibitory effect of NS-398 was overcome by increasing PDGF concentration. SC-236, another COX-2 selective inhibitor, also inhibited PDGF-induced proliferation. In contrast, two selective COX-1 inhibitors, valeryl salicylate and ketorolac, had no significant inhibitory effect on PDGF-stimulated DNA synthesis. The inhibition was obtained when NS-398 was added during the first hour after PDGF addition. At 1 h, PDGF induced COX-2 protein and prostaglandin (PG)E(2) synthesis, and NS-398 blocked the synthesis of PGE(2). The inhibitory effect of NS-398 on PDGF-stimulated DNA synthesis was counteracted by 280 nM PGE(2). The antimitogenic action of NS-398 and SC-236 suggests that selective inhibition of COX-2 may produce antiproliferative effects with substantial safety advantages over nonselective COX inhibitors.

3T3 Cells↗
PubMed1999

Ontogeny of puromycin-sensitive and insensitive aminopeptidase activities in several subcellular fractions of the rat brain.

Puromycin-sensitive and insensitive aminopeptidase (aminopeptidase M) activities are measured in several subcellular fractions of the rat brain cortex and subcortex during the first postnatal month. Tyr-beta-naphthylamide has been used as substrate and 20 microM puromycin as selective inhibitor. We have found that puromycin-sensitive aminopeptidase activity increases twofold in the synaptosomal and mitochondrial fractions in the first 6-9 postnatal days, just during the period of axonal and dendritic growth. This enzyme also has significant age-related changes in the nuclear fraction. The developmental pattern is different, depending on the subcellular fraction analyzed. Significant developmental changes of puromycin-insensitive aminopeptidase (aminopeptidase M) are only found in the myelinic and microsomal fractions and they are less significant than those found in the puromycin-sensitive aminopeptidase. It has been suggested that these enzyme activities could be involved in processes of cell proliferation, differentiation, and maturation.

Analysis of Variance↗
PubMed1999

In vitro evaluation of fludarabine in combination with cyclophosphamide and/or mitoxantrone in B-cell chronic lymphocytic leukemia.

B-chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of long-lived CD5(+) B lymphocytes. We have analyzed the effect in vitro of the combination of fludarabine with cyclophosphamide and/or mitoxantrone on cells from 20 B-CLL patients. Mafosfamide, the active form of cyclophosphamide in vitro, increased the cytotoxicity of fludarabine in all of the patients studied and produced a significant synergistic effect (P <.01) after 48 hours of incubation. The addition of mitoxantrone to this combination increased the cytotoxic effect in cells from 8 patients, but in the remaining 12 patients no significant increase was observed. The effect of fludarabine and mafosfamide was dose-dependent. Mafosfamide and fludarabine had a synergistic effect in inducing apoptosis of B-CLL cells as determined by DNA staining with propidium iodide and analysis of phosphatidylserine exposure. Mafosfamide significantly increased the apoptosis induced by fludarabine on CD19(+) cells (P =.007), but not on CD3(+) cells (P =. 314). Cell viability was correlated with a decrease in Mcl-1 levels and an increase in p53 levels. These results support that fludarabine in combination with cyclophosphamide and/or mitoxantrone can be highly effective in the treatment of B-CLL.

Adult↗
PubMed1999

Ovarian dysplasia in prophylactic oophorectomy specimens: cytogenetic and morphometric correlations.

BACKGROUND: Ovarian dysplasia, a potential precursor to ovarian carcinoma, has been described in ovarian tissue obtained by prophylactic oophorectomy and also adjacent to ovarian carcinoma. Women with a family history of ovarian carcinoma, especially those of Jewish Ashkenazi descent, often test positive for BRCA mutant genes. Prophylactically removed ovaries, generally described as normal on macroscopic examination, can exhibit a "preneoplastic phenotype" and unsuspected neoplasm. METHODS: Histologic slides of ovarian tissue from 54 Ashkenazi Jewish women were reviewed. All had a family history of ovarian carcinoma and all were tested for BRCA mutations. Forty-four women tested positive. Thirty-one women underwent prophylactic oophorectomy and 23 underwent oophorectomy for ovarian carcinoma. Normal, dysplastic, and ovarian carcinoma epithelial cells were analyzed morphometrically combining nuclear area measurements with chromatin texture assessment using a novel method based on the computation of autocorrelation coefficients and a derived parameter (Beta). Discriminant analysis between classificatory algorithms was used to obtain results. RESULTS: Ovarian dysplasia was identified in 77.6% of the prophylactic oophorectomy specimens. An unsuspected ovarian carcinoma was diagnosed in one prophylactic oophorectomy specimen. Of 10 women who underwent prophylactic oophorectomy and were negative for BRCA mutations, three had ovarian dysplasia. The average nuclear measurements of the dysplastic cells were similar to those published previously. The new autocorrelation-based method evaluating nuclear texture, as revealed by tridimensional surface plots, demonstrated high discriminatory potential. Discriminant analysis based on nuclear area and nuclear texture information resulted in the correct classification of nearly all the cases in the three diagnostic categories. CONCLUSIONS: Ovaries removed by prophylactic oophorectomy examined in their entirety often reveal ovarian dysplasia and occasionally ovarian carcinoma. The new morphometric method used was highly discriminatory in the evaluation of nuclear texture. Ovarian dysplasia in women with risk factors for ovarian carcinoma is significant in early ovarian carcinogenesis.

Adult↗
PubMed1999

Caspase inhibition protects nigral neurons against 6-OHDA-induced retrograde degeneration.

6-Hydroxydopamine (6-OHDA) administered intrastriatally to adult rats in a single injection causes neurodegeneration of the nigrostriatal pathway and loss of > 50% of dopamine neurons in substantia nigra pars compacta 30 days after administration. The death of nigral neurons occurs, at least partially, by a caspase-mediated mechanism. The nigral loss of dopaminergic neurons could be prevented by stereotaxical administration of zVAD.fmk, a caspase inhibitor, into the substantia nigra, indicating that 6-OHDA-induced nigrostriatal degeneration involves caspase activation. These results suggest that caspases are probably involved in neurodegenerative chronic processes such as Parkinson's disease and might be considered as possible targets in the treatment of such neurological disorders.

Amino Acid Chloromethyl Ketones↗
PubMed1999

Impairment of the proapoptotic activity of Bax by missense mutations found in gastrointestinal cancers.

We have reported previously that codon 169 of the proapoptotic gene BAX is a mutational hot spot in gastrointestinal cancer. Two different mutations were found in this codon, replacing the wild-type threonine by alanine or methionine. To compare the proapoptotic activity of these Bax mutants with wild-type Bax, we established an ecdysone (muristerone A)-inducible system in cultured human embryonal kidney 293 cells. Addition of muristerone A induced a dose-dependent decrease in the viability of cells transfected with wild-type BAX, but this loss of viability was inhibited in cells transfected with BAX mutants. Furthermore, muristerone A induced morphological changes characteristic of apoptosis, including cell shrinkage, rounding, formation of apoptotic bodies, detachment and nuclear condensation and fragmentation, in cells transfected with wild-type BAX. These hallmarks of apoptosis were clearly diminished in cells transfected with BAX mutants. Mutation of threonine 169 did not affect the binding of Bax to Bax, Bcl-2, or Bcl-X(L). These results demonstrate that missense mutations at codon 169 of BAX are functional because they inhibit its apoptotic activity. This is the first report of the functional significance of missense mutations in BAX, or any other proapoptotic member of the Bcl-2 family, in primary human tumors.

Alanine↗
PubMed1999

Human colon adenocarcinomas express a MUC1-associated novel carbohydrate epitope on core mucin glycans defined by a monoclonal antibody (A10) raised against murine Ehrlich tumor cells.

A monoclonal antibody (mAb; A10) raised against murine Ehrlich tumor cell surface carbohydrates was tested for reactivity with human normal and malignant tissues. A10 reacted strongly, with a high proportion of adenocarcinomas arising from colon and other tissues but not with breast carcinomas or other malignant tumors. Normal tissues were virtually A10 unreactive, except for the duct cells from breast and pancreas and some bronchial mucosae. Ultrastructural studies showed mAb A10 immunolabeling of both microvilli and mucin droplets in colon cancer cells but not in normal absorptive or globet cells. A10 reacted strongly with mucin-enriched fractions from colon cancer tissues and HT-29 xenografts but not from normal colon tissues. A10 epitope was carried on MUC1 derived from colon adenocarcinomas and probably on other mucin species, although not on MUC2 molecules. A10 epitope was resistant to exoglycosidases and periodate oxidation but sensitive to the Smith's degradation and beta-elimination, suggesting the involvement of O-linked carbohydrates in nonterminal reducing positions. A mucin-type glycosidic linkage was supported because of the lack of A10 reactivity with HT-29 cells grown with phenyl-N-acetyl-alpha-D-galactosaminide. Deglycosylation studies with trifluoromethanesulfonic acid pointed to the involvement of core mucin glycans in the A10 epitope. This epitope was resistant to protease, O- and N-glycanase treatments carried out on trifluoromethanesulfonic acid-deglycosylated mucins. Inhibition studies with core 1, core 2, core 3, and core 6 suggested the latter [GlcNAcbeta(1-6)GalNAc] as being involved in A10 epitope. Taken together, the present results point to A10 defining a core 6-related epitope on core mucin glycans expressed by colon cancer MUC1 not previously associated with human cancer.

Adenocarcinoma↗
PubMed1999

Effect of cooling rates on post-thaw sperm motility, membrane integrity, capacitation status and fertility of dairy bull semen used for artificial insemination in Sweden.

We studied the effects of 2 different cooling rates during equilibration of semen from room temperature to 4 degrees C, at 4.2 degrees C/min (control split sample) or at 0.1 degree C/min (treatment split sample) on in vitro sperm viability post thawing and fertility after AI. Forty batches of split-frozen semen from 14 dairy bulls (Swedish Red and White breed) aged 14 to 16 m.o. or 66 to 79 m.o. were evaluated post-thawing for sperm motility (visual and computer-assisted sperm analysis [CASA], membrane integrity (fluorescent microscopy and flow cytometry post-loading with the combined fluorophores Calcein AM/EthD-1 and SYBR-14/PI); acrosomal status (with Pisum sativum agglutinin [PSA] staining); and capacitation status (CTC-assay). Fertility values (56-d nonreturn rate) of the slow cooling batches (treatment) were 0.4% units higher than for faster cooled (control) batches, but the difference was not statistically significant. Fertility values for the older bulls were 1.6% units higher than for the group of younger sires. No statistically significant correlations were found between semen viability parameters assessed in vitro and 56-d nonreturn rate. Visually assessed sperm motility, membrane integrity, capacitation and acrosomal status post-thawing did not differ significantly between cooling procedures, however the percentage of motile spermatozoa and the kinetic characteristics of spermatozoa--average path velocity (VAP), straight path velocity (VSL) and curvilinear velocity (VCL)--assessed by CASA differed significantly between cooling procedures. The results indicate that most of the in vitro sperm viability parameters post-thawing and the fertility results for bulls after AI did not differ significantly between the 2 semen cooling procedures tested.

Acrosome Reaction↗
PubMed1999

[An anomalous origin of the left coronary artery in the right pulmonary artery with interventricular communication].

A six-month-old female baby with a left coronary artery of anomalous origin in the right pulmonary artery, associated with a interventricular septal defect and a slight mitral pathology, was operated on direct implantation of the left coronary artery with a small segment of the pulmonary artery in the posterior wall of the ascending aorta and closure of the perimembranous defect was performed. The patient has been asymptomatic for one year since surgery.

Coronary Vessel Anomalies↗
PubMed1999

Effect of imipramine on enkephalin-degrading peptidases.

In recent years, there has been increasing evidence of the involvement of the endogenous opioid system in mental depression and its treatment. In this work, we have measured the effect of imipramine on enkephalin-degrading peptidases in several rat brain areas. Aminopeptidase activities have been assayed using Tyr-beta-naphthylamide as substrate and puromycin as selective inhibitor. Dansyl-D-Ala-Gly-Phe(pNO2)-Gly has been the substrate for neutral endopeptidase 24.11. Imipramine in vitro inhibits puromycin-sensitive activities in all brain areas studied, without affecting the rest of the enzymes assayed. However, subacute imipramine treatment increases neutral endopeptidase activity in the hypothalamus and chronic treatment increases this activity in the hypothalamus and the striatum. These results suggest to us that enkephalin-degrading peptidases are involved in the acute and chronic action mechanism of imipramine and reinforce the idea that the central enkephalinergic activity is dynamically changed during the treatment of depressive illness.

Animals↗
PubMed1999

Aspirin induces cell death and caspase-dependent phosphatidylserine externalization in HT-29 human colon adenocarcinoma cells.

The induction of cell death by aspirin was analysed in HT-29 colon carcinoma cells. Aspirin induced two hallmarks of apoptosis: nuclear chromatin condensation and increase in phosphatidylserine externalization. However, aspirin did not induce either oligonucleosomal fragmentation of DNA, decrease in DNA content or nuclear fragmentation. The effect of aspirin on Annexin V binding was inhibited by the caspase inhibitor Z-VAD.fmk, indicating the involvement of caspases in the apoptotic action of aspirin. However, aspirin did not induce proteolysis of PARP, suggesting that aspirin does not increase nuclear caspase 3-like activity in HT-29 cells. This finding may be related with the 'atypical' features of aspirin-induced apoptosis in HT-29 cells.

Apoptosis↗