PubMed Health⌕ Search

Biomedical subjects

C Martins

Publications and source records attributed to C Martins.

At least 19 recordsLinked to original sources
PubMed2007

Cytogenetic abnormalities in MALT lymphomas and their precursor lesions from different organs. A fluorescence in situ hybridization (FISH) study.

AIMS: To analyse the possible activation of distinct molecular pathways in mucosa-associated lymphoid tissue (MALT) lymphoma, we determined the prevalence of trisomies 3, 12, 18 in MALT lymphomas from different organs, as well as the prevalence of translocations of the MALT1 gene in a subset of primary breast MALT lymphomas. We compared the numerical cytogenetic alterations in lymphomas, precursor lesions and in normal non-haematolymphoid tissue from the same organs. METHODS AND RESULTS: Forty-two samples of paraffin-embedded tissue (29 MALT lymphomas from stomach, breast, parotid and thyroid; two Sjögren's syndrome; two Hashimoto's thyroiditis and nine reactive samples) were studied by fluorescence in situ hybridization (FISH). Analysed together, the cases of gastric, parotid and thyroid MALT lymphomas presented trisomy 3 in 46%, trisomy 12 in 28% and trisomy 18 in 21% of the cases. In contrast to other locations, trisomy 3 was not present in the majority of the cases of primary breast MALT lymphomas. None of the nine breast cases presented MALT1 gene rearrangements. Half of the cases of preneoplastic lesions exhibited trisomy 3 and trisomy 12; none exhibited trisomy 18. CONCLUSIONS: Trisomy 3 is the most frequent numerical abnormality in gastric, parotid and thyroid but not in primary breast MALT lymphomas. MALT1 gene rearrangements are also rare in this location, suggesting that distinct molecular pathways may be activated in breast cases.

Chromosome Aberrations↗
PubMed2006

Genomic organization and evolution of the 5S ribosomal DNA in Tilapiini fishes.

5S rDNA sequences present an intense dynamism and have proved to be valuable as genetic markers to distinguish closed related species and also in the understanding of the evolutionary dynamic of repetitive sequences in the genomes. In order to identify patterns of 5S rDNA organization and their evolution in the genome of fish species, such genomic segment was investigated in the tilapias Oreochromis niloticus and Tilapia rendalli, and in the hybrid O. urolepis hornorum x O. mossambicus. A dual 5S rDNA system was identified in the three analyzed tilapia samples. Although each 5S rDNA class was conserved among the three samples, a distinct 5S rDNA genome organization pattern could be evidenced for each sample. The presence of a dual 5S rDNA system seems to be a general trait among non-related teleost fish orders, suggesting that evolutionary events of duplication have occurred before the divergence of the main groups of teleost fishes.

Animals↗
PubMed2006

Two sporadic cases of adult-onset progressive mucinous histiocytosis.

Progressive mucinous histiocytosis is a rare, benign, non-Langerhans' cell histiocytosis limited to the skin. Ten cases--all women--in four families and one sporadic case have been described in the literature. The disorder usually begins in childhood and progresses slowly. We report two sporadic cases of adult-onset progressive mucinous histiocytosis in unrelated African-American women, aged 48 and 55 years, respectively, who developed red-brown and flesh-coloured, asymptomatic papules on the face, the arms and the legs without truncal, mucosal or visceral involvement. The lesions showed no spontaneous regression. Both patients lacked associated systemic symptoms, including polyuria, polydipsia or seizures. There was no underlying hyperlipidaemia, paraproteinaemia or lymphoproliferative disease. No family history of similar lesions could be identified. Light microscopy revealed dermal proliferation of spindle-shaped histiocytes with abundant mucin deposition. Electron microscopy demonstrated a high number of myelin figures or zebra bodies in the cytoplasm of histiocytes. On immunohistochemistry, positive staining with macrophage markers--CD68, HAM56 and lysozyme--and factor XIIIa, a transglutaminase present in dermal dendrocytes, and negative staining with Langerhans' cell markers--CD1a and S100--and CD34, a marker present in dermal dendritic cells derived from uncommitted mesenchymal cells, were observed.

Diagnosis, Differential↗
PubMed2005

Development of a nested PCR and its internal control for the detection of African swine fever virus (ASFV) in Ornithodoros erraticus.

A nested PCR assay, with an internal control, was developed to detect African swine fever virus (ASFV) DNA in Ornithodoros erraticus. The assay revealed a better analytical sensitivity than virus isolation and the OIE PCR protocol. All ticks collected from the field, which were positive by virus isolation, were also positive by PCR. Viral DNA was detected in a further 19 out of 60 ticks from which no virus was isolated. Our results show that this assay is reliable and can easily be used to screen large tick populations collected in the field for the presence of ASFV.

African Swine Fever↗
PubMed2005

Healthy diet in primary care: views of general practitioners and nurses from Europe.

BACKGROUND: Most of the national colleges of general practitioners (GPs) do not have their own dietary/nutritional tools, and GPs and nurses do not have the time, knowledge, or skills to advise their patients about desirable dietary practices. OBJECTIVE: To assess the usefulness of a simple and practical guide on healthy diet to be used by European GPs and nurses. DESIGN: A postal survey was mailed to 171 GPs and nurses from 12 European countries to obtain information about the usefulness of a guide on healthy diet developed by EUROPREV. RESULTS: The perception of health professionals is that the main source of information on healthy diet for the population was the media. In all, 95% of GPs and nurses reported that the guide was useful; 93, 95, and 82% reported that the concepts were concise, easy to understand, and realistic, respectively. Also, 77% reported that the type of counselling recommended was feasible and could be applied, 94% reported that the implementation measures proposed could be effective and 88% reported that the Traditional Mediterranean Diet Pyramid is useful, but some concerns about the content were mentioned. CONCLUSIONS: GPs and nurses from Europe think that a practical guide on healthy diet developed by EUROPREV could be used to advise patients in primary care, although the Traditional Mediterranean Diet Pyramid should be modified.

Adult↗
PubMed2005

Oncogene-dependent tumor suppression: using the dark side of the force for cancer therapy.

Cancers arise by an evolutionary process that involves the protracted acquisition by somatic cells of suites of interlocking mutations that uncouple proliferation, survival, migration, and damage responses from the mechanisms (selective pressures) that normally restrain or restrict them in time and space. The relative rareness of cancer cells within the soma, in the face of huge numbers of available cell targets, substantial rates of mutation, and an abundance of proto-oncogenes and tumor suppressor gene targets, indicates that the evolutionary space available to incipient tumor cells is highly restricted. The principal way in which this is achieved is through intrinsic tumor suppression pathways-innate growth arrest and apoptotic programs that fulfill an essentially analogous functional role to checkpoints in the cell cycle machinery by antagonizing the tumorigenic potential of oncogenic mutations. Using switchable transgenic and knockin mouse models, it is possible to identify these various tumor suppressor programs and establish where, when, how, and why they act to forestall neoplasia in each tissue type and, consequently, how and why their failure leads to cancer.

Animals↗
PubMed2005

Occurrence of salmonella in the ileum, ileocolic lymph nodes, tonsils, mandibular lymph nodes and carcasses of pigs slaughtered for consumption.

This study evaluates the occurrence of Salmonella in pork carcasses and in some risk tissues (ileum, ileocolic and mandibular lymph nodes and tonsils), that can be involved in Salmonella contamination during slaughter. Salmonella was identified in 27 (26.7%) pigs and in 13 (12.9%) carcasses. From these positive carcasses, 69.2% presented the same serotype as that identified in the corresponding pig, which emphasize the pigs importance as a source of Salmonella during the slaughter, suggesting that measures should be taken at the level of pig production in order to reduce the slaughtering of Salmonella-positive animals. The highest value of Salmonella occurrence was reached in the ileocolic lymph nodes (18.8%) and in the ileum (13.9%), representing Salmonella potential faecal source during pork processing at the abattoir. In these samples, a high level of Salmonella was observed in the ileocolic lymph nodes in comparison with the ileum. The mandibular lymph nodes (12.9%) also presented a higher occurrence in comparison with the tonsils (9.9%). These results indicate that the lymph nodes analysis could be more sensitive in the detection of Salmonella than the closer drainage tissue. Otherwise, the presence of Salmonella in the lymph nodes indicates lymphatic spread of the organism, which reflects an increased risk of pork contamination. These results also indicate that, in order to achieve a better control of Salmonella contamination during the slaughter process, it is important to consider the improvement of the evisceration practices and the tonsils as well the extraction of mandibular lymph nodes after slaughter.

Abattoirs↗
PubMed2003

Haploidentical stem cell transplantation with purified CD34 cells after a chemotherapy-alone conditioning regimen.

We investigated whether a novel chemotherapy-alone conditioning regimen would permit durable engraftment of standard doses of CD34+ purified stem cell grafts from full-haplotype mismatched related donors. We also examined the role of infusing limited doses of donor leukocytes for prevention of leukemia relapse. Our conditioning regimen consisted of thiotepa, fludarabine, rabbit antithymocyte globulin, melphalan, cyclosporin, and prednisolone. Since October 1998, 14 patients with high-risk leukemia were treated; 13 donor-patient pairs shared 3 of 6 HLA antigens, and 1 pair shared 5 of 6 HLA antigens. A median of 5.4 x 10(6) CD34+ cells per kilogram, 1.62 x 10(4) CD3+ cells per kilogram, and 9.32 x 10(4) CD19+ cells per kilogram were infused. T-cell depletion was the only graft-versus-host disease (GVHD) prophylaxis. All patients had prompt engraftment, and no late graft rejections were observed. All surviving patients received at least 1 infusion of donor whole blood containing 5, 7, 10, 25, or 50 x 10(3) CD3+ cells per kilogram between days 25 and 95 after transplantation, after which 8 developed acute GVHD (3 grade I, 2 grade II, 2 grade III, and 1 grade IV) and 2 developed a bronchiolitis obliterans-like syndrome. After attaining complete remission, 5 patients relapsed and died with active leukemia. The estimated relapse-related mortality at 4 years is 38.1%. As of June 15, 2003, 6 of 14 patients have survived a median of 43.5 months after transplantation with 100% donor cells. All 6 surviving patients developed acute GVHD and had a natural killer cell mismatch with their donors in the direction of graft versus host. The estimated overall survival and event-free survival for the 14 patients at 4 years is 41.7% +/- 13.5%.

Adolescent↗
PubMed2003

Peripheral blood neutrophil function and lymphocyte subpopulations in cycling mares.

The purpose of this study was to evaluate different parameters of the immune status in the mare, during the follicular and the luteal phases of the oestrous cycle, in two consecutive years. Functional competence of peripheral blood neutrophils, such as chemotaxis, phagocytosis and oxidative burst was assessed under physiological cyclic conditions (Exp. I). In the second year of this study (Exp. II), besides peripheral blood neutrophil phagocytosis and oxidative burst analysis, circulating lymphocyte subsets were also characterized. The reproductive status in a total of 17 adult cycling mares was evaluated by ultrasonography and further confirmed by plasma progesterone levels. Chemotaxis tests were performed using porous membranes inserted in transwell chambers. Lipopolysaccharide (LPS) from Escherichia coli and N-formyl-Met-Leu-Phe (fMLP) were used as chemoattractants. Measurement of phagocytosis and oxidative burst in blood neutrophils were assessed by flow cytometry using commercially available kits. Quantification of T-lymphocyte subsets was assessed by indirect immunofluorescence staining after incubation with monoclonal antibodies specific for CD2, CD3, CD4 and CD8 cell markers by flow cytometry. Natural killer cells and B cells were estimated mathematically. No significant difference was found in migration, phagocytosis and oxidative burst at either phase of the oestrous cycle. Statistical analysis of total white blood cell counts also showed no significant difference between either phase of the oestrous cycle, although there was a tendency for blood neutrophils to increase in number under the progesterone influence (p = 0.09). Lymphocytic subpopulations did not differ throughout the oestrous cycle. Overall, our results suggest that luteal and follicular phases in cycling mares may not influence the immune status of the mare.

Animals↗
PubMed2002

Centrosomal abnormalities, multipolar mitoses, and chromosomal instability in head and neck tumours with dysfunctional telomeres.

Carcinomas of the head and neck typically exhibit complex chromosome aberrations but the underlying mutational mechanisms remain obscure. Evaluation of cell division dynamics in low-passage cell lines from three benign and five malignant head and neck tumours revealed a strong positive correlation between multipolarity of the mitotic spindle and the formation of bridges at anaphase in both benign and malignant tumours. Cells exhibiting a high rate of mitotic abnormalities also showed several chromosome termini lacking TTAGGG repeats and a high frequency of dicentric chromosomes. Multicolour karyotyping demonstrated a preferential involvement in structural rearrangements of chromosomes with deficient telomeres. The majority of malignant, mitotically unstable tumours expressed the reverse transcriptase subunit of telomerase. These data indicate that some of the genomic instability in head and neck tumours is initiated by telomere dysfunction, leading to the formation of dicentric chromosomes. These form chromosome bridges at mitosis that could prevent the normal anaphase-telophase transition. In turn, this may cause an accumulation of centrosomes and mitotic multipolarity. Telomerase expression does not confer total stability to the tumour genome but could be crucial for moderating the rate of chromosomal evolution.

Adenoma, Pleomorphic↗
PubMed2002

Dynamics of 5S rDNA in the tilapia (Oreochromis niloticus) genome: repeat units, inverted sequences, pseudogenes and chromosome loci.

In higher eukaryotes, the 5S ribosomal DNA (5S rDNA) is organized in tandem arrays with repeat units composed of a coding region and a non-transcribed spacer sequence (NTS). These tandem arrays can be found on either one or more chromosome pairs. 5S rDNA copies from the tilapia fish, Oreochromis niloticus, were cloned and the nucleotide sequences of the coding region and of the non-transcribed spacer were determined. Moreover, the genomic organization of the 5S rDNA tandem repeats was investigated by fluorescence IN SITU hybridization (FISH) and Southern blot hybridization. Two 5S rDNA classes, one consisting of 1.4-kb repeats and another one with 0.5-kb repeats were identified and designated 5S rDNA type I and type II, respectively. An inverted 5S rRNA gene and a 5S rRNA putative pseudogene were also identified inside the tandem repeats of 5S rDNA type I. FISH permitted the visualization of the 5S rRNA genes at three chromosome loci, one of them consisting of arrays of the 5S rDNA type I, and the two others corresponding to arrays of the 5S rDNA type II. The two classes of the 5S rDNA, the presence of pseudogenes, and the inverted genes observed in the O. niloticus genome might be a consequence of the intense dynamics of the evolution of these tandem repeat elements.

Animals↗
PubMed2002

[Visceral lesions in mammals and birds exposed to agents of human cercarial dermatitis].

Over the past few years, the cercarial dermatitis has become a new problem of public health, obviously linked to the prolonged stay of migrant birds on our territory. This is a skin affection characterized by pruriginous and papulous eruptions caused by penetration of avian bilharzian larvae under the skin. These larvae are emitted by molluscs, mostly limneids. In aquatic birds, especially in migrating Anatidae, these larvae reach the visceral vessels, become adults in a few weeks, lay eggs, then degenerate. Corresponding miracidia contaminate new limneids. Since 1993, the total number of annual cases of cercarial dermatitis has increased from only ten to thousands in France and the affection rages in pools where limneids, migrating water birds and swimmers gather together. Fever, respiratory and/or digestive allergic symptoms appear in some cases. This clinical pattern has encouraged to undertake research on the future of these bilharzian larvae in mammals organism. A preliminary investigation on a rodent model showed that, once the skin barrier had been crossed, the schistosomulae migrated into the lungs of the host; there they survived a week and induced lesions. The goal of this study is to carry on the research, over a longer period, after exposure to cercariae, simultaneously in mammals and birds, with two species of bilharziae present in France. The selected models are the gerbil Meriones unguiculatus for mammals, and the ducks Anas platyrhynchos and Cairina moschata, for birds. 5 M. unguiculatus and 2 A. platyrhynchos were exposed to cercariae emitted by Radix auricularia; 2 gerbils and 5 A. platyryhnchos to larvae of R. peregra, 3 C. moschata to larvae emitted by two species of molluscs: 70-230 from R. auricularia and 330-585 from R. peregra. 5 gerbils died between 2 and 5 weeks after exposure, 2 gerbils sacrificed early, served as control animals for skin manifestations. Eight ducks were sacrificed between 2 and 4 weeks after; the 2 last ones, exposed several times, were sacrificed respectively 7 and 13 weeks after the first exposure. Visceral and skin samples were submitted to histological study. The control gerbils developed skin dermatitis. In ducks, R. auricularia was the vector of Trichobilharzia franki, whose selective dwelling site was the mesentery; R. peregra was the vector of an indeterminate species found in the lungs and nose. This species is called Bilharzia sp. in this study. The ducks, exposed to two kinds of larvae, displayed worms in these two main locations. In gerbils, T. franki induced lesions in the mesenteric veins and the peritoneum. Bilharzia sp. gave rise to lesions in lung arteries, pleura and liver veins. Vascular changes encompassed endothelitis and lymphocytic vasculitis, while serosa displayed mesothelial hyperplasia. The types of lesions observed in gerbils were noticed in ducks, and, according to the species of bilharzia, in the homologous viscera. Additional foreign body granulomas centred on worm's debris or their eggs, and vascular thromboses were present, too. In addition, ducks displayed lesions involving several other viscera including the intestine, the kidneys and the peripheral nerves. These changes were multiple and diffuse in C. moschata exposed to two species of bilharziae. They were observed mainly in mesenteric and intestinal vessels, pulmonary arteries and hepatic veins. In gerbils, the lesions persisted 2 to 5 weeks after exposure, but worms were not identified in the neighbouring tissues near the damaged vessels. In ducks, lesions were important between 2 and 7 weeks after exposure; they co-existed with live or dead worms, sometimes paired, with or without eggs. The hepatic lesions regressed 13 weeks, after exposure. In mammals and birds, young worms could migrate into the same visceral vessels, and stimulating formation of persistent lesions. In individuals exposed to the same cercariae, development of similar lesions would be probable.

Animals↗
PubMed2001

Karyotypic characterization of papillary thyroid carcinomas.

BACKGROUND: Cytogenetic studies performed in papillary thyroid carcinoma (PTC) identified chromosome 10q rearrangements with breakpoints at 10q11.2 as the most frequent aberrations in these tumors. In the current study, the authors aimed to identify other chromosomal abnormalities nonrandomly associated with papillary thyroid carcinomas. METHODS: Cytogenetic analysis was performed on 94 papillary thyroid carcinomas after short-term culture of the tumors sterile fragments. RESULTS: Clonal chromosomal changes were found in 37 tumors (40%). Structural cytogenetic abnormalities were observed in 18 carcinomas. Chromosomes 1, 3, 7, and 10 were the most frequently involved in rearrangements. Pooled results of the breakpoints detected in these tumors, as well as those described in the literature, allowed the authors to verify as the most common breakpoint loci 1p32-36, 1p11-13, 1q, 3p25-26, 7q34-36, and 10q11.2. The correlation between the karyotype features of the 94 PTCs and the histologic data revealed that some PTC follicular variants were characterized by chromosomal aberrations commonly found in thyroid follicular adenomas: a del(11)(q13q13), a t(2;3)(q13;p35), and gains of chromosomes 3, 5, 7, 9, 12, 14, 17, and 20. In the tall cell PTC variant group, 4 of the 7 tumors presented clonal cytogenetic changes, 3 (75%) of which were characterized by anomalies of chromosome 2 that lead to a overrepresentation of the long arm of this chromosome. Noted also in these series was an association between complex karyotypes and tumors with poorly differentiated histiotypes. CONCLUSIONS: In this study, the authors report chromosome 1p32-36, 1p11-13, 3p25-26, and 7q32-36 as novel breakpoint cluster regions in PTC, and they suggest that there are cytogenetic changes preferentially associated with the follicular and tall cell PTC variants.

Adolescent↗
PubMed2001

Cytogenetic similarities between two types of salivary gland carcinomas: adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma.

Adenoid cystic carcinoma (ACC) and polymorphous low-grade adenocarcinoma (PLGA) are low-grade adenocarcinomas of salivary glands with a putative common histogenesis from the intercalated ducts but featuring distinct histological appearances. Hybrid tumors containing areas with histological patterns of both neoplasms have been reported but, to our knowledge, the question of their genotypic similarity has not yet been approached. As part of an ongoing study on cytogenetic characterization of salivary gland tumors, from a group of 24 malignant neoplasms, three out of five cases of ACC and three of four cases of PLGA were selected for their similar karyotypic changes. All of them displayed chromosome 12 abnormalities, affecting the 12q12-q13 region in four (all ACC cases and one PLGA case), 12q22 in one PLGA case, and 12p12.3 in the remaining. From this group of neoplasms, one PLGA and one ACC showed the same t(6;12)(p21;q13). Our findings favor the concept that tumors of salivary glands displaying epithelial and myoepithelial phenotypes share a common histogenesis.

Adenocarcinoma↗
PubMed2001

Nonrandom karyotypic features in basal cell carcinomas of the skin.

Cytogenetic analysis of short-term cultured 44 basal cell carcinomas (BCC) revealed clonal karyotypic abnormalities in 38 tumors. Relatively complex karyotypes (at least four structural and/or numerical changes per clone) with unbalanced structural as well as numerical aberrations were found in eight (approximately 21%) of the BCC, while the remaining BCC (79%) had simple karyotypes (1 to 3 aberrations per clone). Numerical changes only were found in 16 tumors, 15 BCC displayed both numerical and structural aberrations, and the remaining 7 BCC showed only structural aberrations. Extensive intratumoral heterogeneity, in the form of cytogenetically unrelated clones, was found in 21 tumors, whereas related subclones were present in 10 tumors. In order to obtain an overall karyotypic picture in BCC, the findings of our previously published 25 BCC have been reviewed. Our combined data indicate that BCC are characterized by nonrandom karyotypic patterns. A large subset of BCC is characterized by nonrandom numerical changes, notably, +18, +X, +7, and +9. Structural rearrangements often affect chromosomes 1, 4, 2, 3, 9, 7, 16, and 17. A number of chromosomal bands are frequently involved, including 9q22, 1p32, 1p22, 1q11, 1q21, 2q11, 4q21, 4q31, 1p36, 2q37, 3q13, 7q11, 11p15, 16p13, 16q24, 17q21, and 20q13. When the genomic imbalance is assessed, it has been shown that several chromosome segments are repeatedly involved in losses, namely loss of the distal part of 6q, 13q, 4q, 1q, 8q, and 9p. A correlation analysis between the karyotypic patterns and the clinico-histopathologic parameters has been undertaken in the 44 BCC of the present series. The cytogenetic patterns show a significant correlation with tumor status (P=.025), that is, that cytogenetically more complex tumors are also those clinically the most aggressive. Also, the frequency of cytogenetically unrelated clones is significantly higher in recurrent BCC than that in primary lesions (P=.05). No clear-cut association has been found between the karyotypic patterns and histologic subtypes or tumor sites.

Aged↗