Search PubMed⌕ Search

Biomedical subjects

C Martins

Publications and source records attributed to C Martins.

At least 55 records · Page 3Linked to original sources
PubMed1999

In vitro transformation of cell lines from human salivary gland tumors.

Explanted cells from salivary gland tumors are particularly difficult to propagate in vitro and not efficiently immortalized by agents such as simian virus 40. Human papillomavirus 16 (HPV16) has been widely used to transform cells of epithelial origin, but its use for salivary gland cell transformation has not been described. In this study, we employed viral constructs containing the E6/E7 genes of HPV16 to infect and stably transform 9 salivary gland tumor cell cultures. Four of the tumor cell cultures were derived from benign tumors and 5 from malignant tumors. All of the original cell cultures were diploid; however, 6 contained subpopulations of cells with structural abnormalities. All 9 cell cultures were successfully transformed, and 8 were immortalized. The resulting cell lines have decreased serum requirements, exhibit a high proliferation rate, are E6/E7-positive and form colonies in soft agar. Immuno-histochemical and molecular studies confirmed that the transformed cells were indeed epithelial/myoepithelial in origin. All of the transformed cell lines had a diploid or near-diploid karyotype, and 2 contained the original translocated chromosomes in all cells. Our report represents a new application of the E6/E7 system in immortalizing salivary gland cell cultures, resulting in retention of the cellular features found in the native tissue without a general destabilization of the karyotype. These types of tissue culture resources should prove useful for positional cloning and functional studies of genes involved in salivary gland oncogenesis.

Antigens, Differentiation↗
PubMed1999

Nonrandom karyotypic features in squamous cell carcinomas of the skin.

We report the finding of clonal chromosome abnormalities in 13 short-term cultured squamous cell carcinomas (SCCs) of the skin. Intratumor heterogeneity, in the form of cytogenetically related (subclones) or unrelated clones, was detected in six tumors. Whereas clones with complex karyotypic changes were found in 6 tumors, clones with simple anomalies were observed in 10 tumors, and sometimes these clones coexisted with highly abnormal clones. Rearrangement of chromosome 8, in the form of isochromosome i(8q) or whole arm translocation, was the most common aberration, found predominantly in complex clones. Another recurrent feature, i.e., the centromeric rearrangement of chromosome 1, as isochromosome i(1q) or i(1p), or whole arm translocations, was always part of a complex karyotype. Homogeneously staining regions were found in two cases, one with a highly complex karyotype and the other with a simple karyotype. In order to obtain an overall karyotypic picture in SCC of the skin, the cytogenetic findings in 10 SCCs reported earlier were reviewed. The chromosomes most commonly affected were, in decreasing order, chromosomes 1, 11, 8, 9, 5, 3, and 7. Chromosomal sites most frequently rearranged were almost all pericentromeric: they were 8q10-q11, 1p10-q12, 5p10-q11, 11p15, and 9p10-q10. Recurrent anomalies were i(1q), i(8q), i(5p), i(1p), i(9p), and i(9q). Among them, only i(8q) and i(9q) might be assumed to be early genetic events, considering the fact that they could occasionally be identified in simple clones. The most frequent losses included part of or the entire chromosomes 2, 4, 9, 11, 14, 18, and 21, arm 8p, and chromosomes X, Y, and 13. Overrepresentation most frequently involved 1q, chromosome 7, and 8q. The characteristic karyotypic pattern observed in skin SCC was in line with the experience in several other carcinomas. Genes Chromosomes Cancer 26:295-303, 1999.

Aged↗
PubMed1999

Lifetime prevalence of mental disorders among homeless people in a southeast city in Brazil.

Several studies have shown a high prevalence of mental disorders among homeless people. Data from developing countries, like Brazil, are conspicuously lacking, making it difficult to plan interventions targeted to this group's mental health. The sample was selected from street dwellers in Juiz de Fora, a city with 424,479 inhabitants in the Southeast of Brazil. People of 18 years of age or more who had been living outdoors for at least 12 months were eligible for the study. The psychophathology was assessed by using SCAN (Schedule for Clinical Assessment in Neuropsychiatry). After 3 months, it was possible to assess 83 persons. All but one had at least one psychiatric diagnosis according to ICD-10. The most frequent diagnoses were alcohol abuse/dependence (82%), mood disorders (32.5%), drug abuse/dependence (31.3%), and schizophreniform psychosis (9.6%), with a high rate of comorbidity (78.3%). The occurrence of mental disorders was present in almost the entire sample. The authors link this to sampling framing and weakness of the homeless care network system, due to economic constrain and social inequality within the country.

Adolescent↗
PubMed1999

Fluorescent in situ hybridisation (FISH) characterisation of pericentromeric breakpoints on chromosome 5 in head and neck squamous cell carcinomas.

Pericentromeric rearrangements, such as isochromosomes and whole-arm translocations, are frequently encountered in short-term cultures from head and neck squamous cell carcinomas (HNSCC). To characterise further the localisation of the breakpoints in such rearrangements, metaphase cells from seven HNSCC known to carry structural rearrangements of the pericentromeric region of chromosome 5 were investigated using fluorescent in situ hybridisation (FISH) techniques. With a whole chromosome painting probe it could be confirmed that all chromosome 5 rearrangements identified at cytogenetic analysis contained chromosome 5 material. By using a centromere-specific alpha satellite probe it could be shown, however, that cytogenetically identical derivative chromosomes had different breakpoints. Thus, we conclude that the results of the present investigation add further support to the hypothesis that the essential outcome of near-centromeric chromosome rearrangements is the creation of genomic imbalances, i.e. gain and/or loss of neoplasia-associated genes.

Aged↗
PubMed1999

Chromosomal localization of 5S rDNA genes in Leporinus fish (Anostomidae, Characiformes).

The large 45S rDNA chromosome sites have often been analyzed in fish. In contrast, little is known about the 5S genes in this animal group. In the genus Leporinus, the NOR chromosomal location has been shown to be very diverse. In the present work, chromosome mapping of 5S rDNA in three anostomids, Leporinus elongatus, L. obtusidens and L. friderici, is investigated using fluorescence in-situ hybridization (FISH) with PCR-obtained 5S probes and primed in-situ labeling (PRINS). Major 5S rDNA chromosomal sites were found to be subterminally located in a small metacentric pair, while minor ones were detected near the centromeric region of a medium-sized submetacentric pair in all studied species. The 5S rDNA genes were not associated with the NORs or sex chromosomes. A highly conserved chromosomal location of these genes appears to characterize the karyotype evolution of this fish group.

Animals↗
PubMed1999

Characterization of six tumor suppressor genes and microsatellite instability in hepatocellular carcinoma in southern African blacks.

AIM:To analyse cumulative loss of heterozygosity (LOH) of chromosomal regions and tumor suppressor genes in hepatocellular carcinomas (HCCs) from 20 southern African blacks.METHODS: p53,RB1, BRCA1, BRCA2, WT1 and E-cadherin genes were analysed for LOH, and p53 gene was also analysed for the codon 249 mutation, in tumor and adjacent non tumorous liver tissues using molecular techniques and 10 polymorphic microsatellite markers.RESULTS:p53 codon 249 mutation was found in 25% of the subjects,as was expected, because many patients were from Mozambique, a country with high aflatoxin B-1 exposure. LOH was found at the RB1, BRCA2 and WT1 loci in 20%(4/20) of the HCCs, supporting a possible role of these genes in HCC. No LOH was evident in any of the remaining genes. Reports of mutations of p53 and RB1 genes in combination, described in other populations, were not confirmed in this study. Change in microsatellite repeat number was noted at 9/10 microsatellite loci in different HCCs, and changes at two or more loci were detected in 15%(3/20) of subjects.CONCLUSION:We propose that microsatellite/genomic instability may play a role in the pathogenesis of a subset of HCCs in black Africans.

Journal Article↗
PubMed1999

Management of childhood diarrhea and use of oral rehydration salts in a suburban West African community.

In a household survey in Guinea-Bissau, 319 episodes of diarrhea in children were followed by interviews every second day with the aim of investigating perceived morbidity and subsequent actions taken. The majority of the mothers had good knowledge of oral rehydration salts (ORS). However, only 58% of the episodes were treated with ORS and the amount given was insufficient. Mothers with no knowledge of ORS did not use it during the observed attack of diarrhea regardless of contact with a health center, which suggests that maternal knowledge is an important determinant of whether health personnel provide ORS. Children with diarrhea considered to be caused by teething were less likely to receive ORS in the acute phase (risk ratio = 0.6, 95% confidence interval [CI] = 0.5-0.9). Univariate analyses showed that the use of ORS was related to number of reported symptoms, the mother being the care taker, consultations, previous use of ORS, good knowledge of ORS, and having ORS sachets at home. Multivariate Cox regression analyses showed that the presence of ORS sachets at home at the onset of diarrhea was the strongest predictor of use (hazard ratio = 3.3, 95% CI = 1.9-3.6). Improved health education should focus more on the quantity of ORS needed, early signs of dehydration, treatment of teething diarrhea, and breast feeding, and address mothers who have no prior knowledge of ORS. Management of diarrhea may be improved by a more liberal distribution of ORS sachets.

Administration, Oral↗
PubMed1999

Malaria parasitemia and childhood diarrhea in a peri-urban area of Guinea-Bissau.

To examine the association between diarrhea in early childhood and malaria parasitemia, we conducted a nested case-control study in Guinea-Bissau of 297 children with diarrhea and a similar number of children without diarrhea matched for age, season, and residential area. There were no associations between diarrhea and parasite rate, parasite density, or clinical malaria. However, anti-malarials were easily available and frequently used, which was reflected by a 0.7% prevalence of children with a parasite density > 100/200 leukocytes. Thus, the findings do not preclude that diarrhea may be a sign of clinical malaria or high-parasite density in endemic areas with lower use of antimalarials.

Animals↗
PubMed1999

Pleomorphic adenoma gene 1 is expressed in cultured benign and malignant salivary gland tumor cells.

The pleomorphic adenoma gene 1 (PLAG1) is activated by reciprocal chromosomal translocations involving 8q12 in a subset of salivary gland pleomorphic adenomas. PLAG1 encodes a zinc finger protein and was initially reported to be expressed in placenta and fetal tissues, with no detectable expression in other normal adult tissues. By Northern blotting we have detected PLAG1 expression in a wide set of normal adult tissues, including heart, placenta, spleen, prostate, testis, ovary, and small intestine. We have performed reverse transcriptase-PCR and Northern blot analyses to study the expression of PLAG1 in normal salivary gland tissues and in primary cultures and cell lines derived from salivary gland tumors. PLAG1 was expressed in all tumor-derived primary cultures and cell lines, irrespective of their histological type or the presence of genomic rearrangements involving PLAG1, but was not detected by our assays in normal salivary glands. Our data indicate that the presence or absence of PLAG1 expression is not an unequivocal marker for the differential diagnosis of benign versus malignant salivary gland tumors, and that a simple de novo activation of this gene does not fully explain the involvement of this gene in salivary gland tumors.

Adenoma, Pleomorphic↗
PubMed1998

A refined localization of two deleted regions in chromosome 6q associated with salivary gland carcinomas.

Deletions within chromosome 6 (6q25 to 6qter) are the most consistent structural change observed in salivary gland carcinomas. To better define the location of these deletions we investigated loss of heterozygosity (LOH) for 23 polymorphic markers within 19 salivary gland carcinomas covering several histological subtypes. LOH was observed in 47% of tumors, confirming previous reports that such losses are frequent and occur in almost all histological subtypes of tumors. The highest frequency of LOH was found at, or distal to, D6S437. Seven tumors had allelic losses for D6S297 and/or D6S37. A second peak of loss was also observed at D6S262 and D6S32. In some tumors we observed LOH in one or the other of these two regions. In other tumors we observed loss of both regions with retention of intervening loci. These data suggest that two small deletions commonly occur, one between D6S262 and D6S32 (estimated to cover less than 1.5 Mb) and another between D6S297 and D6S446 (estimated to cover approximately 2 Mb). These results extend previous studies by sublocalizing the regions of LOH and suggest that inactivation of one or more tumor suppressor genes located in these regions may be an important step in salivary gland carcinogenesis.

Blotting, Southern↗
PubMed1998

[Squamous cell carcinoma of the face: therapeutic approach].

Cutaneous squamous cell carcinoma is the most common metastatic skin cancer. The importance of early recognition and thorough treatment of premalignant lesions as well as the recognition of risk factors of the neoplasms that are most likely to metastasize must also be emphasized. A retrospective study of 126 patients, treated for primary squamous cell carcinoma of the face, was undertaken over a 7-year period. An attempt is made to define the major therapeutic modalities chosen, taking into consideration the specific anatomic location.

Adult↗
PubMed1998

The use of bovine pericardium for pulmonary valve reconstruction or conduit replacement: long-term clinical follow up.

BACKGROUND AND AIMS OF THE STUDY: This study aimed to determine the clinical performance of bovine pericardial aldehyde-treated material alone or in combination with aortic leaflets of porcine origin. These were the porcine aortic stentless pulmonary valved bovine pericardial conduit (PSPVC), and porcine aortic monocusp attached to pericardial patch (PAMC), used to correct right-sided heart lesions. METHODS: Between November 1985 and October 1995, 33 patients underwent corrective congenital surgery with PSPVC. Mean patient age was 5.7+/-4.3 years (range: 15 days to 18 years). Pulmonary atresia with ventricular septal defect (VSD) was the most frequent disease (16/33, 48%). For PAMC, 45 patients with various congenital heart malformations underwent implantation between June 1989 and April 1996. Mean patient age was 4.8+/-4.7 years (range: 2 weeks to 18 years). RESULTS: With PSPVC, hospital mortality rate was 18.2% and related to poor preoperative clinical condition in six cases. Four patients were lost to follow up; 23 (85%) were followed for 3 months to 10 years (mean 4.8+/-3.0 years). Distal anastomotic scarring in four patients was probably due to retraction of the pericardial tissue. With PAMC, hospital mortality rate was 11% and related to patients' preoperative clinical condition. Three patients were lost to follow up; 37 survivors have been followed for 6 to 88 months (mean 38.5+/-19.0 months). There were no late deaths. Two patients underwent reoperation; intra-operative observation showed well-preserved monocusps with no signs of tissue degeneration. The remaining 35 patients remain asymptomatic by clinical examination and Doppler echocardiography. The monocusps remained mobile in every case. CONCLUSION: PSPVCs have shown excellent performance and durability in young patients with a low mean age (5 years). The monocusp graft has remained functional with good leaflet motion for up to seven years.

Adolescent↗
PubMed1998

Use of bovine pericardial tissue for aortic valve and aortic root replacement: long-term results.

BACKGROUND AND AIMS OF THE STUDY: The study aimed to determine the clinical performance of bovine pericardial aldehyde-treated products alone or in combination with aortic leaflets of porcine origin. These included a composite porcine stentless aortic valve attached to a scalloped pericardial tube (BSAV), and valved and non-valved bovine pericardial conduits for use in left-sided heart lesions (BPG). METHODS: For BSAV grafts, between January 1990 and August 1996, 163 patients (119 males) had their aortic valves replaced by SJM Biocor BASV. Mean age was 37.9 +/- 17.6 years (range: 1 to 76 years). Rheumatic heart disease sequelae (n = 72) and replacement of a prosthetic heart valve (n = 46) were predominant. Preoperative NYHA functional class showed 90 patients (55.2%) in class III and 50 (30.7%) in class IV. BPVC and NVPC grafts were used in 166 patients: acute aortic dissection was the main indication in 52 (31.3%) and chronic in 36 (21/7%). The ascending aorta was involved in 141 patients (84.9%); grafts were seldom used at other sites. In most patients the graft implanted was either a non-valved (n = 79) or a valved (n = 75) pericardial conduit. Twelve patients had a localized lesion and required a patch repair. RESULTS: For BASV grafts, the non-valve-related hospital mortality rate was 4.9%. There were 14.7% non-fatal complications with full recovery of all patients. Mean follow up in 141 patients was 3.0 +/- 1.4 years (range: 1 month to 7.2 years); 14 patients were lost to follow up. Late, non-conduit-related, mortality occurred in seven patients (4.9%). Eight patients underwent reoperation. The current clinical follow up of 127 patients has shown 118 (92.9%) with competent valves and nine (7.0%) with mild stable aortic insufficiency. For BPVC and NVPC grafts, hospital mortality rate was 16.9%, death being related to poor preoperative clinical condition. Postoperative follow up was accomplished in 125 patients; reoperation was necessary in seven patients. Histology showed good tissue preservation up to five years; echocardiography revealed satisfactory findings. No valved conduit had to be reoperated for valve or pericardial tissue wear. CONCLUSIONS: Clinical results of left-sided heterologous pericardial grafts have shown excellent performance over time. The BASV (over seven years) and BPVC and NVPC (eight years) have demonstrated superior results as aortic valves alone or in combination with a pericardial conduit.

Adolescent↗
PubMed1998

FISH characterization of head and neck carcinomas reveals that amplification of band 11q13 is associated with deletion of distal 11q.

In order to characterize homogeneously staining regions (HSR) and other 11q13 rearrangements identified cytogenetically, we performed fluorescence in situ hybridization (FISH) using a CCND1 cosmid and five YAC clones spanning chromosomal bands 11q13-14 on metaphase cells from 14 primary and one metastatic head and neck carcinomas. At the cytogenetic level, a total of 17 HSR were detected in ten cases: five were in derivative chromosomes 11 in band 11q13, and 12 were located in other derivative chromosomes. Other forms of 11q13 rearrangements were observed in five cases, whereas two cases had normal chromosomes 11. FISH analysis demonstrated that all HSR but two were derived from the 11q13 band. The size of the amplicon varied from case to case, but the amplification always included the region covered by YAC 55G7, which contains the CCND1 locus. The amplification of CCND1 was confirmed by use of a CCND1 cosmid. We also showed that most of the cases (9 of 11) with 11q13 amplification had lost material from distal 11q. The breakpoints were mapped by FISH and were shown to cluster to the region between YACs 55G7 and 749G2. We conclude that loss of gene(s) in distal 11q may be as important as amplification of genes in 11q13 for the biological aggressiveness of head and neck carcinomas.

Adult↗
PubMed1998

[Direct coronary angioplasty versus thrombolysis in the acute phase of myocardial infarction--inpatient outcome].

Both thrombolysis and percutaneous transluminal coronary angioplasty (PTCA) are effective methods for the treatment of acute myocardial infarction (AMI). In our centre we perform primary PTCA during the available schedule of the hemodynamics laboratory. In this article we compare the predischarge evolution of patients submitted to each therapeutic procedure. From January 1996 to June 1997, 298 patients were admitted with the diagnosis of AMI. Eighty-four patients (28%) were thrombolysed (TB group) and 30 patients (10%) underwent primary PTCA (PTCA group). There were no significant differences among the two groups concerning demographic characteristics: age (61 +/- 13--TB and 59 +/- 12 years--PTCA); sex (male 81%--TB; 83%--PTCA), risk factors and previous cardiac history. The mean time since the onset of symptoms until arrival at the hospital was 156 +/- 156 minutes for TB and 202 +/- 210 minutes for PTCA (p < 0.02). The delay since admission until the beginning of treatment was 100 +/- 88 minutes for TB and 119 +/- 142 minutes for PTCA. The primary success rate of PTCA was 94% and there were no complications during the procedure. During the hospital stay, 12 patients developed post-infarction angina in the TB group and two patients in the PTCA group; in 15 patients of the TB group a revascularization procedure was performed (surgery in 5 and PTCA in 10 patients); one patient suffered reinfarction in the TB group. Two patients of the TB group (2.4%) had intracranial hemorrhage; the in-hospital mortality was 9.5% in the TB group and 3.3% in the PTCA (p < 0.001). The mean in-hospital stay was 11 +/- 5.6 in the TB group and 7.8 +/- 2.5 days in the PTCA group (p = 0.055). In our experience, primary PTCA in AMI appeared to be a safe procedure with lower occurrence of coronary events and hemorrhagic complication, with an earlier hospital discharge when compared to thrombolysis.

Adult↗
PubMed1998

[Is the stress test useful in the detection of post-angioplasty restenosis?].

Restetenosis is still the greatest limitation of coronary angioplasty (PTCA). The systematic use of ergometry (PE) with the objective of identifying restenosis is controversial and, namely, the ACC/AHA does not recommend its routine use. Our objective was to conduct a retrospective study of the use of PE when performed late (3 to 6 months) for the detection of restenosis. As a protocol, our group performed "late" PE on all the patients without contraindications, the patients with positive ergometry or CCS class II-IV angor submitted to angiographic control. Between January 1996 and July 1997, 121 patients (pts) were submitted to PTCA. Our study population was composed of patients submitted to complete revascularisation with follow-up in our centre: 59 pts (49%) with an average age of 58 +/- 12 years, 82% male. Eighty-three percent of the pts had revascularisation in a context of unstable angina, 10% in the acute phase of myocardial infarction and 7% due to chronic angina. Stents were implanted in 42% of the pts. In the follow-up after six months, 7 pts complained of CCS class II or III angor. The ergometry showed positive electrocardiographic criteria in 11 pts (18.6%). All pts with angor had positive PE. All these pts were submitted to angiographic control; restenosis (residual stenosis equal to or above 50%) was observed in all the patients who complained of angor (100% positive predictive value); restenosis occurred in 9 pts with positive ergometry (82% positive predictive value). In asymptomatic pts, PE indicated 2 pts with restenosis (2/59-3.4%) and two false positive (2/11-18%). At six months, PE detected 22% of the pts with restenosis. In conclusion, complete post-revascularisation angor due to coronary angioplasty has a higher positive predictive value than ergometry. However, the stress test, performed systematically, can identify an additional percentage of pts with restenosis with an acceptable percentage of false positives.

Angioplasty, Balloon, Coronary↗
PubMed1998

[Abciximab (ReoPro) in primary angioplasty].

UNLABELLED: The aim of the study was to evaluate the efficacy and safety of abciximab (ReoPro) in primary percutaneous transluminal coronary angioplasty (P.T.C.A.) in patients with myocardial infarction (M.I.). From June 96 to October 97, 16 patients with a mean age of 58 +/- 12 years, 86% males, with myocardial infarction (less than 12 hours of pain) were treated with ReoPro during P.T.C.A. The infarction was anterior in seven patients (44%), inferior in eight patients (50%) and non-Q wave in one patient (6%). Nine patients (47%) had a previous history of angina or myocardial infarction. The mean time from onset of symptoms to hospital arrival was 306 +/- 370 min and the mean time between hospital admission and the beginning of the procedure was 79 +/- 86 min. P.T.C.A. was performed on the anterior descending artery and right coronary in 44% and 56%, respectively. The success rate was 94%. Stents were used in 31%. In patients with angiographic success, we obtained TIMI III flow in 14 patients and TIMI II in one patient. No complications arose during P.C.T.A; no significant changes in platelets or hemoglobin were observed after the procedure. In this group of patients, one case of hematoma was found at the site of puncture with no need for transfusion. During hospitalization, no major coronary events were found. During the follow-up of 10.5 +/- 4.9 months, one patient died after non cardiac surgery and one patient was submitted to coronary artery bypass graft; there was no reinfarction nor new P.T.C.A. CONCLUSIONS: In our experience with ReoPro during direct angioplasty, we obtained good immediate and long term results, with no significant bleeding complications.

Abciximab↗