Biomedical subjects

C Coelho

Publications and source records attributed to C Coelho.

13 recordsLinked to original sources

PubMed2005

Application of the MAS-J-HMQC experiment to a new pair of nuclei {29Si,31P}: Si5O(PO4)6 and SiP2O7 polymorphs.

We report the results of the two-dimensional MAS-J-HMQC experiment providing scalar correlations between 29Si and 31P nuclei in solid state NMR, and we give the first evaluation of the 2JSi-O-P coupling constants (approximately 15 Hz) for a crystalline silicophosphate phase Si5O(PO4)6. The experiment is applied to the characterization of complex mixtures of SiP2O7 phases, through editing of 31P spin pairs by the heteronuclear 2JP-O-Si interaction.

Journal Article↗

PubMed2005

Indoor air pollution in old people's homes related to some health problems: a survey study.

UNLABELLED: The present research reports on a survey of 96 subjects between the ages of 60 and 95 years, living close to Paris in a social collective habitat. The aim was to show, using goodness-of-fit statistical tests (P < 0.1), how old people lifestyles can subject them to generated chemical or bacteriological indoor pollutants. Risk factors due to lifestyles were analyzed in relation to complaints and to health condition. There are many ways that old people are exposed to pollutants: difficulty in maintaining the residence, preference for staying in the kitchens, substantial use of cleaning chemicals. However, the principal risk for health problems is arguably inadequate ventilation (unclean screens, blocked air vents, etc.), which increases the concentration of indoor pollutants. These risks are amplified by ignorance about the hazards of inadequate ventilation. PRACTICAL IMPLICATIONS: The present investigation suggests that the lifestyle and the behavior of old people could be the cause of an interior air pollution of their housing. Measures realized in representative dwellings selected in relation to results must confirm that these risks would require the installation of an automatic monitoring system of the indoor air near these people.

Activities of Daily Living↗

PubMed2003

Comparison between specific and multiplex reverse transcription-polymerase chain reaction for detection of hepatitis A virus, poliovirus and rotavirus in experimentally seeded oysters.

Outbreaks of gastroenteritis have occurred among consumers of raw or undercooked shellfish harvested from faecally polluted waters. A multiplex reverse transcription-polymerase chain reaction (RT-PCR) was applied for the simultaneous detection of hepatitis A virus (HAV), poliovirus (PV) and simian rotavirus (RV-SA11) and compared with specific primers for each genome sequence. Three amplified DNA products representing HAV (192 bp), PV (394 bp) and RV (278 bp) were identified when positive controls were used. However, when tested on experimentally contaminated raw oysters, this method was not able to detect the three viruses simultaneously. This is probably due to the low concentration of viral RNAs present in oyster extract which were partially lost during the extracts preparation.

Animals↗

PubMed2003

Hepatitis A virus detection in oysters (Crassostrea gigas) in Santa Catarina State, Brazil, by reverse transcription-polymerase chain reaction.

Shellfish are readily contaminated with viruses present in water containing sewage because of the concentration effect of filter feeding. Hepatitis A virus (HAV) is the main cause of acute hepatitis worldwide and may lead to severe illness or even death. It is transmitted through fecal and oral routes and causes widespread endemic and asymptomatic infections in young children. Here we describe a method for the detection of HAV RNA in shellfish involving the extraction of total RNA from oyster meat followed by reverse transcription-polymerase chain reaction (RT-PCR). Virus recovery from oyster extracts artificially seeded with HAV strain HM 175 was examined by RT-PCR. The minimum detection limit was 3.3 focus-forming units of HAV, and the recovery rate was 75.7%. This method was used to assess the viral contamination of four shellfish beds in Santa Catarina State, Brazil, over a 1-year period. Six (22%) of 27 samples collected in autumn and winter from one shellfish bed tested positive for HAV.

Animals↗

PubMed2002

Treatment of Papillon-Lefèvre syndrome periodontitis.

BACKGROUND, AIMS: Conventional mechanical treatment of Papillon-Lefèvre syndrome periodontitis has a poor prognosis. This report describes an effective antimicrobial treatment of rapidly progressing periodontitis in an 11-year old girl having Papillon-Lefèvre syndrome. METHOD: Clinical examination included conventional periodontal measurements and radiographic analysis. Occurrence of major suspected periodontopathic bacteria was determined by selective and non-selective culture and by polymerase chain reaction (PCR) identification. Presence of cytomegalovirus and Epstein-Barr type 1 virus was determined by a nested-PCR detection method. Therapy included scaling and root planing, oral hygiene instruction, and systemic amoxicillin-metronidazole therapy (250 mg of each/3 times daily/10 days) which, based on follow-up microbiological testing, was repeated after 4 months. Supportive periodontal therapy took place at 2 visits during a 16-month period. RESULTS: At baseline, 10 of 22 available teeth demonstrated severe periodontal breakdown. At 16 months, probing and radiographic measurements revealed no teeth with additional attachment loss, and several teeth exhibited significant reduction in gingivitis and pocket depth, increase in radiographic alveolar bone height and clinical attachment level, and radiographic evidence of crestal lamina dura. Baseline subgingival microbiota included Actinobacillus actinomycetemcomitans (3.4% of total isolates), Prevotella nigrescens (16.4%), Fusobacteriumnucleatum (14.3%) and Peptostreptococcus micros (10.6%), as well as cytomegalovirus and Epstein-Barr type 1 virus. At termination of the study, culture and PCR examinations showed absence of A. actinomycetemcomitans, P. micros and herpesviruses, and P. nigrescens and F.nucleatum each comprised less than 0.1 % of subgingival isolates. CONCLUSION: This study suggests that controlling the periodontopathic microbiota by appropriate antibiotic and conventional periodontal therapy can arrest Papillon-Lefèvre syndrome periodontitis.

Aggregatibacter actinomycetemcomitans↗

PubMed2001

Diffusion-weighted MR imaging of cystic lesions of neurocysticercosis: a preliminary study.

Neurocysticercosis is an endemic disease in some developing countries. It has pleomorfic clinical and imaging findings, which are variable from patient to patient. In this preliminary note, we studied the magnetic resonance (MR) diffusion-weighted images (DWI) of sixteen patients presenting with cystic lesions of this disease diagnosed by clinical and laboratorial findings. All the lesions had hypointense signal and the similar apparent diffusion coeficient (ADC) values as the cerebrospinal fluid (CSF).

Adult↗

PubMed2000

[Acute effects of tobacco and vascular risk modulated by genetic factors].

Most studies regarding the acute effects of cigarette smoking refer to the higher sympathetic and adrenomedullary activity as a result of sympathetic ganglia and adrenal medulla nicotinic receptor activation. Although it is reasonable to suppose that the renin-angiotensin system might be activated, this possible effect of nicotine has not been studied. We have studied the effects of cigarette smoking on blood pressure, cardiac output, pulse pressure, renin-angiotensin system, kinins-NO, oxidative stress and insulin. Also, we have investigated if the variability of the biochemical parameters was dependent on genetic polymorphisms of the angiotensin converting enzyme and the acute phase protein haptoglobin. 39 normotensive individuals, 18 males and 21 females, of mean age 35.4 +/- 8.9 years were included in this study. Oxidative stress was dependent on the ACE I/D and Hp1/2 polymorphisms, with the ACE DD genotype and the Hp2-2 phenotype not showing variation in the anti-oxidant defense systems, and the ACE II-ID genotypes and Hp1-1 + 2-2 phenotypes showing a higher anti-oxidant response, hence a lower cardiovascular risk being predictable in the latter individuals.

Adult↗

PubMed1999

Microbiological features of Papillon-Lefèvre syndrome periodontitis.

Papillon-Lefevre syndrome patients exhibit hyperkeratosis palmo-plantaris and severe periodontitis. The syndrome is an autosomal recessive trait, but the mechanism of periodontal destruction is not known. This report presents the clinical and microbiological features of an 11-year old girl with Papillon-Lefèvre syndrome. Clinical examination included conventional periodontal measurements and radiographic analysis. In samples from 3 deep periodontal lesions, the occurrence of major suspected periodontopathic bacteria was determined by selective and non-selective culture and polymerase chain reaction (PCR) identification, and the presence of cytomegalovirus and Epstein-Barr type 1 virus by a nested-PCR detection method. 10 of 22 available teeth demonstrated severe periodontal breakdown. Major cultivable bacteria included Actinobacillus actinomycetemcomitans (3.4% of total isolates), Prevotella nigrescens (16.4%), Fusobacterium nucleatum (14.3%) and Peptostreptococcus micros (10.6%). A. actinomycetemcomitans, P. nigrescens, Porphyromonas gingivalis and Eikenella corrodens were identified by PCR analysis. The patient's non-affected parents and older brother revealed several periodontal pathogens but not A. actinomycetemcomitans. The viral examination demonstrated cytomegalovirus and Epstein-Barr type 1 virus in the subgingival sample of the Papillon-Lefèvre syndrome patient. The father and brother yielded subgingival cytomegalovirus but not Epstein-Barr type 1 virus. We hypothesize that human herpesviruses in concert with A. actinomycetemcomitans play important rôles in the development of Papillon-Lefèvre syndrome periodontitis.

Aggregatibacter actinomycetemcomitans↗

PubMed1999

A low protein diet alters the balance of islet cell replication and apoptosis in the fetal and neonatal rat and is associated with a reduced pancreatic expression of insulin-like growth factor-II.

A programmed turnover of pancreatic beta cells occurs in the neonatal rat involving a loss of beta cells by apoptosis, and their replacement by islet cell replication and neogenesis. The timing of apoptosis is associated with a loss of expression of a survival factor, insulin-like growth factor-II (IGF-II), in the pancreatic islets. Offspring from rats chronically fed a low protein isocalorific diet (LP) exhibit a reduced pancreatic beta cell mass at birth and a reduced insulin secretion in later life. This study therefore investigated the impact of LP on islet cell ontogeny in the late fetal and neonatal rat, and any associated changes in the presence of IGFs and their binding proteins (IGFBPs). Pregnant Wistar rats were fed either LP (8% protein) or normal (C) (20% protein) chow from shortly after conception until the offspring were 21 days postnatal (PN). Bromo-deoxyuridine (BrdU) was administered 1 h before rats were killed and pancreata removed from animals between 19.5 days fetal life and postnatal day 21. Offspring of rats given LP diet had reduced birthweight, pancreatic beta cell mass, and pancreas insulin content, with smaller islets compared with control fed animals, which persisted to weaning. Histological analysis showed that islets from pups given LP diet had a lower nuclear labeling index with BrdU in the beta cells, although, paradoxically, more beta cells showed immunoreactivity for proliferating cell nuclear antigen (PCNA). Because PCNA is present in G1 as well as S phase of the cell cycle, we quantified the number of beta cells immunopositive for cyclin D1, a marker of G1, and NEK2, an indicator of cells in G2 and mitosis. More beta cells in islets from LP-fed animals contained cyclin D1, but less contained NEK2 than did those in controls. This suggests that the beta cell cycle may have a prolonged G1 phase in LP-fed animals in vivo. Offspring of rats given C diet had a low rate of islet cell apoptosis detected by the TUNEL method in fetal and neonatal life (1-2%), with a transient increase to 8% at PN day 14. Offspring of rats receiving LP diet demonstrated a significantly greater level of islet cell apoptosis at every age, rising to 15% at PN 14. IGF-II mRNA was quantified in whole pancreas and was significantly reduced in LP-fed animals at ages up to PN day 10. IGF-II immunoreactivity within the islets of LP-fed rats was also less apparent, but no changes were seen in immunoreactive IGF-I or IGFBPs-2 to -5. These findings show that LP diet changes the balance of beta cell replication and apoptosis in fetal and neonatal neonatal life, which may involve an altered length of beta cell cycle, and contribute to the smaller islet size and impaired insulin release seen in later life. A reduced pancreatic expression of IGF-II may contribute to the lower beta cell proliferation rate and increased apoptosis seen in the fetus and neonate after feeding LP diet.

Animals↗

PubMed1998

The Drosophila protein Dof is specifically required for FGF signaling.

Receptor tyrosine kinases (RTKs) transmit signals to the cell nucleus via the MAP kinase (MAPK) cascade, using specific molecules to link the activated receptors to the MAPK cascade activator, Ras. We have identified a component of the FGF receptor (FGFR) signal transduction pathway, Downstream of FGFR (Dof). Dof is an intracellular protein that is essential for signal transmission by the FGFR and acts downstream of the receptor and upstream of Ras. Unlike other signaling molecules that act downstream of RTKs, Dof is not expressed ubiquitously but is present exclusively in cells that express FGFRs. Dof is needed in these cells for activation of the MAPK cascade via FGF signaling, but not for activation via other RTK ligands. Dof therefore appears to be committed exclusively to FGFR-mediated signal transduction.

Amino Acid Sequence↗

PubMed1996

ERECT WING, the Drosophila member of a family of DNA binding proteins is required in imaginal myoblasts for flight muscle development.

The erect wing locus of the fruit fly Drosophila melanogaster encodes a protein, EWG, that shares extensive homology with the P3A2 DNA binding protein of sea urchin and a recently identified mammalian transcription factor. Loss-of-function erect wing alleles result in embryonic lethality. Viable alleles of erect wing cause severe abnormalities of the indirect flight muscles. We have analyzed the spatial pattern of erect wing expression in the developing indirect flight muscles during postembryonic development. EWG is detected, 10 hours after puparium formation, in myoblasts that will form the indirect flight muscles. The early events of muscle development are normal in ewg mutants. However, a few hours after the onset of erect wing expression in myoblasts, defects are seen in the developing indirect flight muscles which subsequently degenerate. We present results that show that the normal development of the indirect flight muscles requires erect wing expression in the progenitor myoblasts themselves. Finally, we examine the role of target muscles in the arborization of motor axons by studying the developing innervation to the flight muscle in erect wing mutants. Our study demonstrates, for the first time, a role for a regulatory gene expressed in imaginal myoblasts in Drosophila.

Animals↗

PubMed1995

Normal genetic response to gamma irradiation in familial adenomatous polyposis.

The present study, a co-operative project between three European institutes, was aimed at elucidating whether the APC gene in carriers of familial adenomatous polyposis coli (FAP) also causes some genetic sensitivity revealed by DNA damage and the yield of chromosome aberrations in peripheral blood lymphocytes exposed to gamma rays. In addition, it seemed of interest to study whether DNA repair is modified after irradiation of lymphocytes from FAP patients compared to controls. To this end, we have used the inhibition of the poly(ADP-ribose) polymerase (ADPRP) by 3-aminobenzamide (3ABA) and studied the effect of 3ABA on the frequency of DNA strand breaks and chromosome aberrations. The data indicate that FAP is not associated with an increased chromosomal sensitivity towards ionising radiation.

Adenomatous Polyposis Coli↗

PubMed1995

Laryngeal function in postpolio patients.

Of the 250,000 survivors of the polio epidemics, approximately 25% experience progressive muscle weakness known as postpolio syndrome (PPS). Laryngeal function in postpolio patients previously has not been studied. This paper presents data detailing laryngeal function in a group of postpolio patients who had been evaluated for swallowing complaints. Nine patients underwent comprehensive history and physical exam, acoustical voice analysis, and laryngeal videostroboscopic endoscopy. Three patients underwent laryngeal electromyography (EMG) evaluation. Results indicated some degree of phonatory or laryngeal deficit in all subjects. Subjects with dysphagia also demonstrated vocal fold paralysis. EMG revealed decreased recruitment and increased amplitude, findings consistent with EMG studies in skeletal muscle in postpolio patients. Results suggest that postpolio patients who complain of swallowing difficulties are at risk for laryngeal pathology.

Aged↗