Biomedical subjects

M Monteiro

Publications and source records attributed to M Monteiro.

At least 19 recordsLinked to original sources

PubMed2006

Impact of chemical exposure on the fish Pomatoschistus microps Krøyer (1838) in estuaries of the Portuguese Northwest coast.

Juveniles of the estuarine fish Pomatoschistus microps were collected from autumn 2001 to summer 2002 in five stations along the Portuguese Northwest coast with different types and/or levels of environmental contamination: two reference sites with low levels of contamination (R1 and R2) and three differently impacted areas with higher levels of contamination. UI is located in an estuary under the influence of urban and industrial effluents, AA in a channel that receives intensive agriculture run-off and IE in a highly impacted industrial area. The activity of the enzymes acetylcholinesterase (AChE), lactate dehydrogenase (LDH), 7-ethoxyresorufin O-deethylase (EROD) and glutathione S-transferases (GST) were used as environmental biomarkers on P. microps. A significant seasonality effect on all the enzymatic activities was found, lower levels being registered in winter and spring on AChE, in autumn on LDH, and in winter on GST and EROD. The battery of biomarkers used was capable of discriminating sites with different types and/or levels of contamination, R1 and UI being the highest discriminated (91.7% and 66.7%, respectively). At R1 significantly lower levels of AChE and LDH were found, and EROD was significantly inducted at UI. Furthermore, IE presented higher levels of GST, and R2 and AA an inhibition of AChE in winter and spring. The results indicated that the battery of biomarkers used in this study seems to be a useful tool to distinguish between different types of environmental contamination in estuarine systems, and that P. microps is a suitable species to be used as bioindicator.

Acetylcholinesterase↗

PubMed2006

Environmental pollution and natural populations: a biomarkers case study from the Iberian Atlantic coast.

The degradation of estuaries is a result of human activities which overloads the environment with substances of both industrial and/or natural origins. Bioindicators have been consistently used to interpret effects of contaminants in the environment. In this study, the use of biomarkers (particular measurable characteristics of a bioindicator organism) was used to evaluate the contamination by xenobiotics of Crangon crangon natural populations. The central aim was to evaluate the capability of a battery of biomarkers to discriminate sites with different types of contamination. The activity of the enzymes cholinesterases (ChE), lactate dehydrogenase (LDH) and glutathione S-transferases (GST) were used as biomarkers. In addition, the ChE form(s) present in the cephalotorax of C. crangon were characterised. Organisms were seasonally sampled from winter 2001/2002 to autumn of 2002, at "reference" sites and at sites that receive agricultural, industrial and/or urban effluents. Results obtained in the characterisation of ChE with different substrates and selective inhibitors demonstrate that the form of ChE present in the cephalotorax of C. crangon shows proprieties of vertebrates' AChE and therefore it may be classified as true AChE-like ChE. The battery of biomarkers exhibited seasonal and local variations, apparently related to agricultural, industrial or urban effluent contamination. The tested biomarkers proved to be able to discriminate sources of environmental contamination, and confirms C. crangon as a sensitive species suitable to be used as a bioindicator.

Analysis of Variance↗

PubMed2006

Evaluation of a new IOL scleral fixation technique without capsular support.

PURPOSE: The purpose of this study was to compare a new intraocular lens (IOL) scleral fixation technique (scleral incision) with the scleral flap surgical technique as regards to efficacy, surgical complications, advantages, disadvantages, and surgery costs in cases with no capsular support. MATERIAL AND METHODS: This was a retrospective study conducted on thirty patients (30 eyes), ten of whom were aphakic, eleven had traumatic cataract, seven had post-phacoemulsification complications, and two had lens luxation. The patients were divided into two groups (I - scleral incision technique and II - scleral flap technique) of fifteen patients each, during a study period lasting eighteen months. The great majority of the procedures were performed under general anesthesia and by the same surgeon. Statistical analysis was done using SPSS. The numerical variables were compared using the t test and the categorical ones using the Fisher exact test. We performed multifactorial analysis to build a model that could predict and compare the complications associated with each technique. An explicative model was built using logistic regression. RESULTS: We observed a threefold higher rate of complications associated with the scleral flap technique when compared to the scleral incision technique. This difference was particularly relevant as regards the occurrence of free scleral flap and hyphema. No statistically significant differences were observed regarding vitreous hemorrhage, choroidal hemorrhage, retinal detachment, difficulty in the external pulling of the Prolene suture, breaking of the Prolene suture, and anterior chamber collapse. We found a significant association between intraoperative complications and the technique used (higher number of complications with the scleral flap) and also with some systemic diseases (patients with hypertension had more intraoperative complications). The number of late complications resulting from the scleral flap technique was much higher than those observed with the scleral incision technique; however, the number of the cases we studied is insufficient to reach statistical significance. CONCLUSION: The duration of the procedure using the IOL scleral incision technique is significantly lower than using the scleral flap technique. Intraoperative complications were significantly associated with the technique used: more frequent with scleral flap. Late complications were mainly associated with systemic and previous ocular diseases.

Eye Diseases↗

PubMed2006

Subcutaneous administration of ghrelin stimulates energy intake in healthy lean human volunteers.

BACKGROUND: The gastric hormone ghrelin appears a useful agent to stimulate food intake in people with anorexia of illness. The loss of ghrelin's acyl group renders it inactive, thus it has been thought that subcutaneous administration may be problematic. OBJECTIVE: To investigate whether human subjects are sensitive to the effects of ghrelin administered by single subcutaneous injection. STUDY DESIGN: Randomized, double-blind, placebo-controlled trial. SUBJECTS: Sixteen healthy lean volunteers (eight men and eight women). PROTOCOL: Fasted subjects received subcutaneous injections of ghrelin (3.6 nmol/kg) or saline. After 30 min, a buffet breakfast was served. RESULTS: Ghrelin injection increased energy intake by 27% (ghrelin 5076 +/- 691 kJ versus saline 4230+/-607 kJ, P = 0.04). Ghrelin appeared to enhance the perceived palatability of the food offered (palatability score: ghrelin 81.1 +/- 3.6 versus saline 70.0 +/- 4.4; P = 0.03). CONCLUSIONS: These results suggest that subcutaneous ghrelin is effective at stimulating energy intake and improving palatability and may be of direct use in the treatment of appetite loss.

Adult↗

PubMed2005

Acute effects of 3,4-dichloroaniline on biomarkers and spleen histology of the common goby Pomatoschistus microps.

The aromatic amine 3,4-dichloroaniline (DCA) is a model environmental contaminant, precursor for synthesis and degradation product of several herbicides, which is commonly found in European estuarine ecosystems. In this work, the possibility of using biochemical and histological markers to assess sub-lethal effects of DCA in natural populations of Pomatoschistus microps juveniles was investigated. Alterations on the activities of the enzymes acetylcholinesterase (AChE), lactate dehydrogenase (LDH) and glutathione S-transferase (GST) and histological alterations on spleen were investigated after 96 h of exposure to sublethal concentrations of DCA (0.50-1.49 mg/l). At the concentrations tested, DCA had no effect on AChE activity. LDH and GST activities were significant altered in treated animals when compared to control groups. As already described for mammals, DCA induced splenic histological alterations in P. microps, including expansion of red pulp and deposition of hemosiderin granules in a concentration-dependent manner. This suggests that DCA is a xenobiotic of concern in estuaries receiving agricultural effluents.

Acetylcholinesterase↗

PubMed2005

Identification of oligomers in polyethyleneterephthalate bottles for mineral water and fruit juice. Development and validation of a high-performance liquid chromatographic method for the determination of first series cyclic trimer.

Cyclic oligomers were identified in PET bottles used for mineral water and fruit juice using MS and (1)H and (13)C NMR: a first series cyclic trimer, a first series cyclic tetramer, a first series cyclic dimmer and a second series cyclic trimer. An analytical method to determine first series cyclic trimer in these bottles was developed and validated, using HPLC. The first series cyclic trimer levels were 316-462 mg/100g of PET bottle.

Beverages↗

PubMed2005

Migration of diethylhexyl phthalate from PVC bags into intravenous cyclosporine solutions.

The migration of diethylhexyl phthalate (DEHP) from PVC bags into LVPS (0.9% NaCl) and LVPS with cyclosporine at concentrations of 2.5 and 0.5mg/ml was studied. PVC bags were placed in contact with these solutions and stored at 25+/-1 degrees C. They were taken for analysis each 30 min during 6 h and after this period at each 1 h until 12 h of contact. Water was used as reference, and exposed and analyzed under the same conditions. After contact, the solutions were submitted to extraction with hexane and analyzed by GC-FID. The results showed that DEHP did not migrate into water and LVPS during all the time. Also, no measurable amount of DEHP was detected during the first 3 h of contact between the PVC bag and the diluted cyclosporine solution. However, the amount of released DEHP reached a detectable level after 4 h of contact, increased until 6 h, stabilized, and increased again after 9-10 h. The 12 h of contact showed the highest DEHP levels for both cyclosporine concentrations. The DEHP migrated was 0.02-0.08% of that present in the bag.

Chromatography, Gas↗

PubMed2005

Intravascular large B-cell lymphoma of the breast.

The case of an 80-year-old woman with symmetrical breast engorgement and nonspecific systemic symptoms progressively developing over 3 months and confirmed on surgical biopsy to be due to an intravascular large B-cell lymphoma (ILBCL) is presented. To our knowledge, ILBCL has never been reported in the breast before and its mammography and ultrasound appearances are described.

Aged↗

PubMed2005

Characterization of the cholinesterases present in head tissues of the estuarine fish Pomatoschistus microps: application to biomonitoring.

In recent years biomarkers have been widely used for the assessment of effects and/or exposure to environmental contaminants. One of the most frequently used biomarkers is the inhibition of cholinesterases (ChE), which is a useful indicator of organophosphate and carbamate exposure and/or effects. Recent studies indicated that more than one ChE may be present in tissues of fish and that different forms may vary in their sensitivity to anticholinesterase agents. Cholinesterase activity of the juvenile of the common goby (Pomatoschistus microps), a widespread fish in estuaries of the Atlantic coast of northwestern Europe, was characterized using four substrates (acetylthiocholine iodide, acetyl-beta-metylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulfate, BW284C51, and iso-OMPA) in different tissues of the fish head. In addition, the range of ChE activity that may be considered as "normal" for non-exposed P. microps was determined. The results suggest the presence of two types of ChE in the whole-head homogenate. The present study underscores the relevance of ChE characterization before its use as a biomarker in biomonitoring studies.

Animals↗

PubMed2002

Molecular analysis of collagen XVIII reveals novel mutations, presence of a third isoform, and possible genetic heterogeneity in Knobloch syndrome.

Knobloch syndrome (KS) is a rare disease characterized by severe ocular alterations, including vitreoretinal degeneration associated with retinal detachment and occipital scalp defect. The responsible gene, COL18A1, has been mapped to 21q22.3, and, on the basis of the analysis of one family, we have demonstrated that a mutation affecting only one of the three COL18A1 isoforms causes this phenotype. We report here the results of the screening of both the entire coding region and the exon-intron boundaries of the COL18A1 gene (which includes 43 exons), in eight unrelated patients with KS. Besides 20 polymorphic changes, we identified 6 different pathogenic changes in both alleles of five unrelated patients with KS (three compound heterozygotes and two homozygotes). All are truncating mutations leading to deficiency of one or all collagen XVIII isoforms and endostatin. We have verified that, in exon 41, the deletion c3514-3515delCT, found in three unrelated alleles, is embedded in different haplotypes, suggesting that this mutation has occurred more than once. In addition, our results provide evidence of nonallelic genetic heterogeneity in KS. We also show that the longest human isoform (NC11-728) is expressed in several tissues (including the human eye) and that lack of either the short variant or all of the collagen XVIII isoforms causes similar phenotypes but that those patients who lack all forms present more-severe ocular alterations. Despite the small sample size, we found low endostatin plasma levels in those patients with mutations leading to deficiency of all isoforms; in addition, it seems that absence of all collagen XVIII isoforms causes predisposition to epilepsy.

Adolescent↗

PubMed2002

Case report: sacrococcygeal teratoma with malignant transformation in an adult female: CT and MRI findings.

This report describes a case of sacrococcygeal teratoma with adenocarcinomatous transformation in a 45-year-old woman. This is an infrequent location for teratoma in adults and malignant transformation has rarely been described. Prognosis depends on complete excision. Clinical manifestations, imaging aspects and histological findings of this case are presented. CT and MRI adequately document the mixed cystic and solid nature of the tumour, its extension and relations with adjacent structures, allowing accurate pre-operative planning.

Adenocarcinoma↗

PubMed2001

Measles antibody responses after early two dose trials in Guinea-Bissau with Edmonston-Zagreb and Schwarz standard-titre measles vaccine: better antibody increase from booster dose of the Edmonston-Zagreb vaccine.

In Guinea-Bissau, children were randomised at 6 months of age to receive either two doses of standard-titre measles vaccine at 6 and 9 months of age or an inactivated polio vaccine at 6 months and standard-titre measles vaccine at 9 months of age. During the first 5 months, children received Edmonston-Zagreb (EZ) vaccine and during the following 11 months, the Schwarz (SW) vaccine. Five percent of the mothers, 74% of children at 6 months of age, and 92% of unvaccinated children at 9 months of age had unprotective levels (<125 mIU/ml) of measles antibodies. Among children receiving EZ vaccine, 1% were unprotected at 18 months of age after either two (3/240) or one (3/211) doses of vaccine, the geometric mean measles antibody titre (GMT) being approximately 1550 mIU/ml in both groups. Among those receiving SW vaccine 9% (34/365) and 3% (9/310) were unprotected at 18 months of age in the two-dose and the one-dose groups (RR = 3.21 (95% confidence interval (CI) 1.56-6.58)), respectively. The GMT was higher after one dose of SW vaccine at 9 months of age (2491 mIU/ml) than after two doses of SW vaccine (1125 mIU) (P < 0.001). In the EZ vaccine group, there was no significant difference in antibody level for children vaccinated in the presence of high or low levels of maternal antibodies, whereas there was a marked difference in the SW group. The second EZ vaccine induced a significant antibody increase between 9 months of age (1191 mIU) and 18 months of age (1602 mIU, P=0.011), whereas antibody levels tended to decline from 9 months (1243 mIU) to 18 months of age (998 mIU, P = 0.124) after the second dose of SW vaccine. Conclusively, after two doses of EZ measles vaccine more children were protected at 18 months of age than after two doses of SW. One dose of SW provided the highest antibody response, but a higher proportion of unprotected than one or two doses of EZ. The EZ vaccine was less sensitive to maternal antibodies, and able to increase the antibody response by revaccination, while the second SW vaccine resulted in an unchanged or lower antibody response.

Age Factors↗

PubMed2001

Substance abuse policy and peace in the Middle East: a Palestinian and Israeli partnership.

This paper describes the working exchange between Israelis, Palestinians and international experts who engaged in a process to promote communications, cooperation and coordination of efforts directed toward peace as well as the prevention and treatment of drug abuse in the region. From 1997 to 1999, a program of training workshops and courses, drug prevention and treatment skills development and collaborative research was conducted on the basis of mutual respect and cooperation among Palestinians and Israelis. By tapping into the issue of substance abuse and by focusing on its professional and academic dimensions, this initiative engaged representative delegations of the police force, academia, treatment centers and various government ministries. While events of this period underscored the dependence of "bottom-up" peace initiatives on the prevailing political situation, the experience revealed the vital role of NGO frameworks in providing a safety net for promoting and sustaining relations as well as addressing an issue of common concern. This case study shows that addiction professionals, both clinicians and researchers, can be instrumental in conflict resolution as well as the prevention and treatment of drug abuse.

Health Policy↗

PubMed2001

Therapeutic exercise in the treatment of patients with lumbar spinal stenosis.

Lumbar spinal stenosis is a condition that may cause significant pain and associated disability, especially in older patients. It is being recognized with increasing frequency as the population continues to age, and is the most common diagnosis associated with lumbar spine surgery in patients older than 65 years of age. The natural history of lumbar spinal stenosis is not necessarily one of progressive deterioration. Conservative treatment is advocated in patients with mild to moderate symptoms of lumbar spinal stenosis, and may include therapeutic exercise. The therapeutic exercise program must be prescribed with a thorough understanding of the contributing pathoanatomic and pathophysiologic factors, and should be tailored to each patient based on his or her history and physical examination. Components of the program are described in detail and include specific stretching and strengthening exercises, general conditioning exercises, and education in proper posture and body mechanics. Randomized controlled studies are needed to help clarify the indications for conservative versus surgical treatment, to determine which components of the therapeutic exercise program are the most beneficial, and to compare outcomes after conservative or surgical measures.

Aged↗

PubMed2001

Challenges and approaches to estimating mortality attributable to the use of selected illicit drugs.

A number of unique challenges are faced when attempting to estimate mortality attributable to illicit drugs. The hidden nature of illicit drug use creates difficulties in quantifying the prevalence of such use; identifying adverse health effects associated with exposure, and calculating the risk of these effects. The use of cohort studies of drug users allows the identification of causes of mortality associated with drug use and the determination of the risk of these causes. This risk estimate can then be used in conjunction with estimates of the prevalence of drug use to extrapolate the burden of mortality. We identify a number of such studies and present some solutions to the major challenges faced when attempting to estimate the global burden of mortality attributable to illicit drug use.

Cohort Studies↗

PubMed2001

Steps towards constructing a global comparative risk analysis for alcohol consumption: determining indicators and empirical weights for patterns of drinking, deciding about theoretical minimum, and dealing with different consequences.

In order to conduct a comparative risk analysis for alcohol within the Global Burden of Disease Study (GBD 2000), several questions had to be answered. (1) What are the appropriate dimensions for alcohol consumption and how can they be categorized? The average volume of alcohol and patterns of drinking were selected as dimensions. Both dimensions could be looked upon as continuous but were categorized for practical purposes. The average volume of drinking was categorized into the following categories: abstention; drinking 1 (> 0-19.99 g pure alcohol daily for females, > 0-39.99 g for males); drinking 2 (20-39.99 g for females, 40-59.99 g for males), and drinking 3 (> or =40 g for females, > or =60 g for males). Patterns of drinking were categorized into four levels of detrimental impact based on an optimal scaling analysis of key informant ratings. (2) What is the theoretical minimum for both dimensions? A pattern of regular light drinking (at most 1 drink every day) was selected as theoretical minimum for established market economies for all people above age 45. For all other regions and age groups, the theoretical minimum was set to zero. Potential problems and uncertainties with this selection are discussed. (3) What are the health outcomes for alcohol and how do they relate to the dimensions? Overall, more than 60 disease conditions were identified as being related to alcohol consumption. Most chronic conditions seem to be related to volume only (exceptions are coronary heart disease and ischemic stroke), and most acute conditions seem to be related to volume and patterns. In addition, using methodology based on aggregate data, patterns were relevant for attributing harms for men but not women.

Adolescent↗

PubMed2000

Cyclin' toward dementia: cell cycle abnormalities and abortive oncogenesis in Alzheimer disease.

Recent evidence has associated the aberrant, proximal re-expression of various cell cycle control elements with neuronal vulnerability in Alzheimer disease, a chronic neurodegeneration. Such ectopic localization of various cyclins, cyclin-dependent kinases, and cyclin inhibitors in neurons can be seen as an attempt to re-enter the cell cycle. Given that primary neurons are terminally differentiated, any attempted re-entry into the cell division cycle in this postmitotic environment will be dysregulated. Since successful dysregulation of the cell cycle is also the hallmark of a neoplasm, early cell-cycle pathophysiology in Alzheimer disease may recruit oncogenic signal transduction mechanisms and, hence, can be viewed as an abortive neoplastic transformation.

Alzheimer Disease↗

PubMed2000

Abortive oncogeny and cell cycle-mediated events in Alzheimer disease.

Alzheimer disease, the leading cause of senile dementia, is characterised by the degeneration of select neuronal populations. While the mechanism(s) underlying such cell loss are largely unknown, recent findings indicate inappropriate re-entry into the cell cycle resembling an abortive oncogeny. In postmitotic neurons, such mitotic re-entrance is deleterious and one that involves virtually the entire spectrum of the described pathological events in Alzheimer disease including, ultimately, cell death.

Alzheimer Disease↗