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Biomedical subjects

E Monteiro

Publications and source records attributed to E Monteiro.

At least 19 recordsLinked to original sources
PubMed2006

Liver enzymes and ultrastructure in rabbit haemorrhagic disease (RHD).

Rabbit haemorrhagic disease (RHD) is caused by a calicivirus infection that kills most adult rabbits 24-72 h after viral inoculation. Two liver enzymes (AST, aspartate aminotransferase, and ALT, alanine aminotransferase) were monitored in blood samples of calicivirus-infected rabbits during the short course of RHD. Values of AST were used to differentiate three stages of hepatocellular degeneration in RHD: mild (up to 20-fold increase in AST), moderate (150-200-fold elevation of AST) and severe (more than 1000-fold elevation in AST). Liver samples of rabbits from these three biochemical stages of hepatocellular degeneration of RHD were studied by transmission electron microscopy to define the fine structure of the hepatocytes. In the mild hepatocellular degeneration there was proliferation (microvesiculation) of the smooth endoplasmic reticulum and swelling of mitochondria into spheroid bodies with loss of cristae. In moderate hepatocellular degeneration, vacuolization of cytoplasm and mitochondrial damage continued to be present, and there was also formation of autophagic vesicles. In the severe hepatocellular degeneration of RHD, the altered mitochondria also showed loss of density of their matrix; rupture of cytoplasmic vacuoles led to the formation of large vesicles. Marked depletion of liver glycogen was also found in this late stage of RHD. These data offer a correlation between biochemical and cytological features of the liver during the hepatocellular degeneration of RHD.

Animals↗
PubMed2005

Crohn's disease: increased mortality 10 years after diagnosis in a Europe-wide population based cohort.

BACKGROUND: No previous correlation between phenotype at diagnosis of Crohn's disease (CD) and mortality has been performed. We assessed the predictive value of phenotype at diagnosis on overall and disease related mortality in a European cohort of CD patients. METHODS: Overall and disease related mortality were recorded 10 years after diagnosis in a prospectively assembled, uniformly diagnosed European population based inception cohort of 380 CD patients diagnosed between 1991 and 1993. Standardised mortality ratios (SMRs) were calculated for geographic and phenotypic subgroups at diagnosis. RESULTS: Thirty seven deaths were observed in the entire cohort whereas 21.5 deaths were expected (SMR 1.85 (95% CI 1.30-2.55)). Mortality risk was significantly increased in both females (SMR 1.93 (95% CI 1.10-3.14)) and males (SMR 1.79 (95% CI 1.11-2.73)). Patients from northern European centres had a significant overall increased mortality risk (SMR 2.04 (95% CI 1.32-3.01)) whereas a tendency towards increased overall mortality risk was also observed in the south (SMR 1.55 (95% CI 0.80-2.70)). Mortality risk was increased in patients with colonic disease location and with inflammatory disease behaviour at diagnosis. Mortality risk was also increased in the age group above 40 years at diagnosis for both total and CD related causes. Excess mortality was mainly due to gastrointestinal causes that were related to CD. CONCLUSIONS: This European multinational population based study revealed an increased overall mortality risk in CD patients 10 years after diagnosis, and age above 40 years at diagnosis was found to be the sole factor associated with increased mortality risk.

Adolescent↗
PubMed2005

Severe leukopenia and liver biochemistry changes in adult rabbits after calicivirus infection.

Calicivirus infection is the major cause of the severe decrease in the stocks of wild and farm rabbits that has occurred worldwide during the last two decades. Adult rabbits (10-weeks-old) were experimentally infected with a calicivirus inoculum that killed all animals by causing rabbit haemorrhagic disease (RHD) within 24-62 h of infection. The rabbits were used to evaluate blood cell numbers and serum biochemistry every 6h, starting 12h after the inoculation of the caliciviruses. No significant changes in blood parameters were observed in most of the rabbits up to 18 h of infection. Severe leukopenia was seen 6h before death of the infected rabbits; both heterophils and lymphocytes contributed to the decrease in circulating white blood cells. Platelets were also severely decreased in number. Marked enhancement in liver enzymes was seen 6-12 h before death of the infected rabbits. There was also evidence both for cholestasis, as expressed by the elevated levels of direct (conjugated) bilirubin, and for hypoglycemia, an alteration that it is likely to contribute for the seizures that rabbits show during the late stages of RHD. Liver ultrastructure of rabbits that died from RHD revealed extensive hepatocyte vacuolization, severe changes in mitochondrial structure, and depletion of glycogen granules. We conclude that: (i) severe leukopenia characterizes the final hours of calicivirus-induced RHD; (ii) hypoglycemia and cholestasis precede death of rabbits from RHD; (iii) the kinetics of liver enzymes allows an accurate prediction of the time of death of rabbits from calicivirus-induced RHD.

Animals↗
PubMed2005

Leukocyte-hepatocyte interaction in calicivirus infection: differences between rabbits that are resistant or susceptible to rabbit haemorrhagic disease (RHD).

Calicivirus infection is lethal for adult rabbits, whereas young rabbits (less than 8-weeks-old) are resistant to the same infectious agent. The virus replicates in the liver and causes a fulminant hepatitis in adult rabbits leading to rabbit haemorrhagic disease (RHD); this is in contrast with the mild and transient hepatitis observed in infected young rabbits. We have used electron microscopy to compare liver leukocyte infiltrates between young (resistant) and adult (susceptible) rabbits, 36-48 h after inoculation of the animals with caliciviruses. In adult rabbits, liver infiltrates were made up mostly of heterophils, and they were located near hepatocytes showing severe cellular damage. In contrast, liver leukocyte infiltrates of RHD-resistant young rabbits were dominated by lymphocytes that depicted membrane contacts with the cell surface of undamaged hepatocytes. We conclude that: (i) the cellular inflammatory response of the liver to calicivirus infection is different in rabbits that are susceptible (adult) or resistant (young) to RHD; (ii) leukocyte infiltration of the adult liver by heterophils is probably directed at the removal of dead hepatocytes, whereas the liver lymphocytic infiltration of young rabbits suggests the expression of viral antigens on the surface of liver cells of the RHD-resistant animals.

Age Factors↗
PubMed2005

Polymorphisms of the human OGG1 gene in laryngeal cancer: implications in radiotherapy response and survival.

UNLABELLED: The human OGG1 (hOGG1) gene encodes a DNA glycosylase involved in the excision repair of 8-hydroxy-2'-deoxyguanine (8-OH-dG) from oxidatively-damaged DNA. Ser326Cys polymorphism in the hOGG1 gene is involved in the repair of 8-hydroxyguanine in oxidatively damaged DNA, and appears to be related to susceptibility to certain smoking and alcohol-related orolaryngeal cancers. OBJECTIVE: To analyse if hOGG1 Ser326Cys (exon 7: m6) polymorphism is associated with tumour localization, T, stage and histologic differentiation, and if radiotherapy results were influenced by this polymorphism. MATERIAL AND METHOD: Blood samples were obtained before treatment from seventy one patients with laryngeal cancer and screened by a PCR-RFLP method. RESULTS: Although hOGG1 gene is important in DNA repair mechanisms, no significant association was observed between hOGG1 Ser326Cys (exon 7: m6) polymorphism, tumour characteristics and radiotherapy results. CONCLUSION: So the analysis of this polymorphism is not important for treatment decision in laryngeal cancer patients.

Adult↗
PubMed2004

Transient decrease in blood heterophils and sustained liver damage caused by calicivirus infection of young rabbits that are naturally resistant to rabbit haemorrhagic disease.

Young rabbits are naturally resistant to rabbit haemorrhagic disease (RHD) caused by the same calicivirus that kills, within 3 days, nearly all adult animals. We have investigated changes in blood leukocytes, and in the morphology and biochemistry of the liver (the organ where caliciviruses replicate) of young rabbits undergoing benign infection by the RHD virus. Four-week-old rabbits were infected with a calicivirus inoculum having a titre of 2(12) haemagglutination units either sacrificed 18, 24, 48 and 72 h later, or kept for follow-up studies up to 21 days after inoculation. The infection caused an acute and transient decrease in blood heterophils, and sustained enhancement in hepatic transaminases. Inflammatory infiltrates of the liver were seen in all animals after 24 h of infection; they had a predominant midlobular location. Hepatocytes could present different degrees of cell damage, including cell death; these lesions were limited to the liver cells located around the inflammatory infiltrates. Liver transaminases peaked 24-48 h after calicivirus infection; this was the same timing when liver infiltration and hepatocyte damage were more evident. No alterations of other parameters of liver biochemistry were observed. We conclude that calicivirus infection of young rabbits causes a subclinical disorder characterised by an acute and transient decrease in circulating heterophils, and focal liver damage that is expressed by intralobular infiltration by heterophils, initially, and, later on, by mononuclear cells. Our finding of persistence of increased values of liver transaminases suggests chronicity of the infection in young rabbits. We propose that, although resistant to RHD, young rabbits infected by calicivirus may be long-term carriers of the infectious agent and, thus, become a major source of transmission of the virus.

Animals↗
PubMed2003

CYP1A1 and XRCC1 gene polymorphisms in SCC of the larynx.

The present study was undertaken to examine CYP1A1 and XRCC1 polymorphisms as potential genetic susceptibility markers for laryngeal squamous cell carcinoma (SCC). Eighty-eight patients with laryngeal SCC and 178 randomly selected healthy blood donors from the same Caucasian population (Porto, Northern Portugal) were analysed for CYP1A1 (MspI and NcoI) and XRCC1 (Arg194Trp and Arg399Gln) polymorphisms, using PCR-RFLP techniques. CYP1A1 MspI MH (mutant homozygous) and CYP1A1 NcoI HT (heterozygous) genotypes were more frequent in patients than in controls, with those carrying a CYP1A1 NcoI HT genotype having a 2.3-fold higher risk for tumour development. On the other hand, polymorphisms in XRCC1 codon 399 and codon 194 do not seem to play a role in the aetiology of smoking-related laryngeal SCC, once its distribution was similar in both analysed groups. All the significant associations observed were exclusively due to differences between controls and larynx glottic cancer patient subgroup. Furthermore, lower lifetime tobacco consumption was observed in laryngeal SCC patients carrying the MspI and NcoI polymorphisms, than in those who did not show the polymorphic variants. This investigation seems to support the importance of CYP1A1 gene polymorphism as a potential genetic marker of laryngeal cancer development, specially concerning smokers who have inherited the at-risk genotypes CYP1A1 MspI MH or CYP1A1 NcoI HT, who do appear to be more susceptible to the development of SCC of the glottic larynx.

Adult↗
PubMed2003

Big is beautiful: electronic patient records in large Norwegian hospitals 1980s-2001.

OBJECTIVES: This paper aims to describe and analyze the prolonged efforts - spanning close to two decades - of developing and using electronic patient records in the large, university-based hospitals in Norway. METHODS: This study belongs to an interpretative approach to the development and use of information systems. RESULTS: The increase in organizational, institutional, political and technological complexity has been seriously underestimated. This paper describes and analyses the prolonged efforts - spanning close to two decades - of developing and using EPRs in the large, university-based hospitals in Norway. The investments involved were considerable, implying that a crucial aspect of these efforts has been the way alliances have been forged with public institutions and agendas. CONCLUSIONS: The conditions for small-scale, bottom-up and evolutionary approaches never succeeded in constructing themselves as a viable alternative to the larger, more sweeping electronic patient record initiative, reiterating a more general tendency to privilege the more comprehensive and daring projects.

Diffusion of Innovation↗
PubMed2003

Integrating health information systems: a critical appraisal.

OBJECTIVES: The aim of this paper is to critically assess some of the underlying assumptions behind these initiatives and analyze the dominant expressions, forms and mechanisms of integration. METHODS: This paper employs a discourse analysis to elicit the notion of integration of information systems and its consequences for electronic patient record systems. RESULTS AND CONCLUSIONS: An alternative strategy is outlined, encouraging a more decentralized, multi-vocal approach acknowledging the productive role of related and duplicated information and preserving the existing variety of information systems.

Ergonomics↗
PubMed2003

Cyfra 21.1, TPS and SCC in squamous cell carcinoma of larynx.

BACKGROUND: Serologic tumor markers are actually a valuable tool for diagnosis, management and follow up in some cancer types. The concentrations of Cyfra 21.1, SCC and TPS has been analysed in several groups of head and neck tumors, but exclusively in larynx there are no studies concerning this subject. AIMS: The purpose of the present study was to assess the expression of serum fragments of cytokeratins (CK's) 18/19, and squamous cell carcinoma antigen (SCCA) in a same group of patients with squamous cell carcinoma of larynx, and correlate the results with tumor localisation, T, stage, histology, presence of regional metastasis, and smoking habits. METHODS: Forty six patients treated at the Department of Otorhinolaryngology, Porto Center of the Portuguese Institute of Oncology were enrolled in the study. Blood samples were obtained before treatment, and determinations effectuated using standard commercial available kits. RESULTS: Although serum concentrations of Cyfra 21.1, TPS and SCC were not significantly elevated in patients with laryngeal cancer, more expressive levels namely for TPS were observed in advanced supraglotic and metastasis tumors independent of the differentiation degree.

Antigens, Neoplasm↗
PubMed2002

Tumour morphology and radiotherapy immediate response in laryngeal tumours.

Laryngeal cancer is relatively frequent in South Europe countries and its incidence suffered variations in last decades. Treatment options are usually based on histology, T category and stage. Tumors unchain in neighbour tissues the presence of cells that normally are associated to inflammatory response. A possible association between tumour inflammatory response and radiotherapy efficacy is focused in occasional papers. Several histological parameters (histologic type, nuclear grade, desmoplasia, necrosis, and cells normally involved in inflammatory response) were analysed in biopsy material obtained from 67 patients with laryngeal cancer treated with primary radiotherapy in our department. Statistical analyses were made in order to assess a possible association between tumour morphology and radiotherapy response.

Adult↗
PubMed2001

Tracheal transplantation: cytological changes studied by scanning and transmission electron microscopy in the rabbit.

OBJECTIVES: Our goal was to offer a comprehensive cytological study of the changes in the trachea after experimental transplantation of the organ. STUDY DESIGN: Autografting of four tracheal rings was done in rabbits and tracheal samples were observed by electron microscopy from 1 week to 6 months after the surgery was performed. METHODS: Transmission and scanning electron microscopy were used to investigate the fine structure of tracheal samples of rabbits submitted to autotransplantation, and quantitative methods were used to compare several cytological parameters of the different groups of animals. RESULTS: We found that tracheal autografting was associated with acute injury of ciliated cells expressed by loss of more than 90% of cilia density on the tracheal epithelium 1 week after the transplantation was performed. The loss of cilia was balanced by an increase in mucous cells present on the tracheal lumen. Recovery of ciliated cells was observed 1 month after the tracheal autografting was performed. In contrast, only mild cytological modifications were seen in the cartilage tissue of the autografted trachea during the first weeks of transplantation; the structural alterations of the cartilage progressed up to the third month after transplantation, resulting in a moderate tracheal stenosis. CONCLUSIONS: The data indicate that 1) autotransplantation of four tracheal rings is a viable surgical procedure; 2) tracheal grafting causes severe acute changes of the epithelium that are, however, reversible in nature; whereas 3) the initial mild alterations induced by the autografting in the cartilage may evolve into tracheal stenosis.

Animals↗
PubMed2001

PCR template preparation for capillary DNA sequencing.

Fluorescence-based capillary DNA sequencing has facilitated the early completion of several complex sequencing projects. While capillary systems offer great benefits in terms of ease of use and automation, we find that they are sufficiently different from slab gel separation methodologies, demanding re-examination of the protocols used to generate and use DNA sequencing templates. We have recently initiated a large-scale Human Open Reading Frame EST project involving 30 laboratories feeding 11 MegaBace 1000 capillary sequencers. The group has already produced more than 300,000 valid sequences. The most successful template preparation protocol we have found is described here. We have found that a crucial step is the standardization of the quantity and quality of the templates, which have been achieved by overnight bacterial culture followed by PCR using limiting amounts of primers. Using this protocol, there is no need for post-PCR purification, and the final preparation cost is US $0.09/template. After sequencing 10,848 templates using this protocol, 78% of the reads were accepted (after discarding vectors without inserts and inserts smaller than 100 nucleotides), and 85% of the total number of bases had Phred scores of 15 or above.

Polymerase Chain Reaction↗
PubMed2001

Prognosis in patients with heart failure and preserved left ventricular systolic function.

BACKGROUND: It is recognized that heart failure patients with preserved left ventricular systolic function have better prognosis; nevertheless, there are some studies with conflicting results. Also, there is a paucity of data concerning the prognostic factors in this group of patients. OBJECTIVES: To determine possible variables with prognostic relevance in heart failure patients with preserved left ventricular systolic function (ejection fraction > 40%). METHODS: 157 consecutive ambulatory patients with heart failure were assessed; those patients with ejection fraction > 40% were included in the study (n = 46). All patients were evaluated by clinical interview and physical examination, ECG, echocardiogram (M-mode, 2D and pulsed Doppler of mitral flow), biochemical study and determination of type B natriuretic peptide (BNP). The patients were grouped according to the rhythm presented on ECG: Group I--patients with atrial fibrillation; Group II--patients in sinus rhythm Group II was further subdivided in two groups according to the presence or absence of restrictive left ventricular filling pattern. All patients had a clinical follow-up, with recording of events (death or hospitalization from cardiac cause). The mean follow-up time was 682.2 +/- 55 days. RESULTS: The mean age of the patients was 70.4 +/- 1.2 years; 54.3% were women; mean ejection fraction was 49.6 +/- 1%; mean BNP levels were 202.9 +/- 41.3 pg/ml. Mortality was 19.6% and the combined event death or hospitalization from cardiac cause) occurred in 26.1% of the patients. Among the clinical, demographic, biochemical, echocardiographic and neurohumoral parameters, only BNP levels had prognostic significance in the whole population. In Group II patients, BNP levels, heart rate and restrictive left ventricular filling pattern were identified as having prognostic significance. Kaplan-Meyer curve analysis showed that both BNP and restrictive left ventricular filling pattern seemed to be important prognostic markers. CONCLUSIONS: This preliminary study suggests thar neurohumoral activity (determined by plasma BNP levels) and a restrictive ventricular filling pattern may be important factors in prognostic stratification of heart failure patients with preserved left ventricular systolic function.

Aged↗
PubMed2001

Echocardiographic patterns and prognosis in heart failure.

BACKGROUND: There are many variables with prognostic value in patients with heart failure (HF). Those related to left ventricular function are among the most important. Recently, the evaluation of the patterns of ventricular filling by pulsed Doppler echocardiography has been studied as a variable with prognostic value. OBJECTIVES: To evaluate the prognostic value of echocardiography variables (diastolic and systolic) in patients with HF. These variables were analysed in respect to hospital admission for cardiovascular reasons or death. MATERIAL AND METHODS: We evaluated 157 consecutive patients with HF and included 110 patients who were in sinus rhythm. The mean age was 68.2 +/- 0.9 years. HF was ischemic in 52.7%. Patients underwent echocardiography examination within the week of reference. The patients were grouped according to left ventricular (LV) systolic dysfunction (LV ejection fraction < 40%). We also classified patients in two groups according to the presence of a restrictive pattern in diastolic transmitral flow profile. Finally, we classified all patients in four groups according to their systolic function and diastolic pattern: Group I--systolic dysfunction and restrictive ventricular filling pattern. Group II--systolic dysfunction without restrictive ventricular filling pattern. Group III--without systolic dysfunction with restrictive ventricular filling pattern. Group IV--without systolic dysfunction without restrictive ventricular filling pattern. The events were death or hospital admission. The mean follow up time was 625 +/- 55 days. We did a statistical analysis and for all tests a p value < 0.05 was considered statistically significant. RESULTS: We found impaired LV systolic function (systolic HF) in 73.6% and restrictive ventricular filling pattern in 45.5%. During the follow-up 41.8% died or were admitted to hospital. Patients with systolic HF had lower admission free survival rate. Patients with restrictive ventricular filling pattern had lower admission free survival rate than those without. Group I had lower admission free survival rate than Group II and Group IV. Group IV had a higher admission free survival than all other Groups. CONCLUSIONS: These results support and expand previous observations that diastolic function variables, such as the pattern of ventricular filling (namely the restrictive) have independent prognostic value in patients with HF.

Aged↗