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R Martins

Publications and source records attributed to R Martins.

At least 19 recordsLinked to original sources
PubMed2004

VOLUS--a visualization system for 3D ultrasound data.

The main goal of this paper is the description of a computer based system for medical applications to estimate the half-ellipsoid model that fits the left ventricle on its two phases of cardiac cycle: diastole and systole. Techniques for registration and rendering of ultrasound images will be presented using 2D freehand spatial calibrated echocardiography images in order to represent the 3D reconstructed data equivalent to the scanned volume. The 3D reconstruction will be used to estimate and measure parameters of the half-ellipsoid model fitted to the left ventricle.

Echocardiography, Three-Dimensional↗
PubMed2003

Early olfactory involvement in Alzheimer's disease.

BACKGROUND: In Alzheimer's disease (AD) the olfactory system, including the olfactory bulb, a limbic paleocortex is severely damaged. The occurrence of early olfactory deficits and the presence of senile plaques and neurofibrillary tangles in olfactory bulb were reported previously by a few authors. The goal of the present study was to analyze the occurrence of AD-type degenerative changes in the peripheral part of the olfactory system and to answer the question whether the frequency and severity of changes in the olfactory bulb and tract are associated with those of the cerebral cortex in AD. MATERIAL AND METHODS: In 110 autopsy cases several cortical areas and the olfactory bulb and tract were analyzed using histo- and immunohistochemical techniques. Based on a semiquantitative analysis of cortical senile plaques, neurofibrillary tangles and curly fibers, the 110 cases were divided into four groups: 19 cases with severe (definite AD), 14 cases with moderate, 58 cases with discrete and 19 control cases without AD-type cortical changes. RESULTS: The number of cases with olfactory involvement was very high, more than 84% in the three groups with cortical AD-type lesions. Degenerative olfactory changes were present in all 19 definite AD cases, and in two of the 19 controls. The statistical analysis showed a significant association between the peripheral olfactory and cortical degenerative changes with respect to their frequency and severity (P < 0.001). Neurofibrillary tangles and neuropil threads appear in the olfactory system as early as in entorhinal cortex. CONCLUSION: The results indicate a close relationship between the olfactory and cortical degenerative changes and indicate that the involvement of the olfactory bulb and tract is one of the earliest events in the degenerative process of the central nervous system in AD.

Adult↗
PubMed2001

Isolation, characterization and quantification of microcystins (heptapeptides hepatotoxins) in Microcystis aeruginosa dominated bloom of Lalla Takerkoust lake-reservoir (Morocco).

This paper presents the first data on the identification, characterization and quantification of microcystins isolated from both an extract of a cyanobacteria natural bloom, collected from a eutrophic Moroccan reservoir (Lalla Takerkoust, Marrakesh) and an isolated strain cultivated under laboratory conditions. The isolation and purification of toxins was performed by reverse phase HPLC and then characterized by amino acid analysis and fast atom bombardment mass spectrometry (FAB-MS). Chemical characterization of the toxins from the bloom revealed variants of microcystins such as Mcyst-LR, Mcyst-RR, Mcyst-YR and [D-Asp3]Mcyst-LR. However, the Microcystis aeruginosa strain produced only Mcyst-RR. Using an ELISA assay the total microcystin contents of eight bloom samples collected from 1994 to 1997 ranged from 0.7 to 8.8 microg/mg of lyophilized material. The two isolated Microcystis strains contained higher amounts of microcystins (0.65 microg/ mg of dry weight) than the Pseudanabaena strains (0.021 microg/mg of dry weight). Our results show that the presence of cyanobacteria toxins in water used for drinking in a North African country may be regarded as an health hazard. These results are a contribution to the knowledge of the biogeography of toxic cyanobacteria and their toxins, namely in north African countries.

Bacterial Toxins↗
PubMed2001

[Mitral flow propagation velocity assessed with M-mode color Doppler in patients with dilated cardiomyopathy].

BACKGROUND: The role of diastolic disfunction in the setting of severe left ventricular (LV) disfunction is usually forgotten due to difficulties in quantification and interpretation. The propagation velocity (PV) of mitral inflow into the left ventricle has been proposed as a load independent indicator of LV diastolic function. Our aim was to correlate PV with age, body surface, chambers dimensions, wall thickness and with classic parameters of systolic and diastolic function. We had in mind the validation of this index in the quantification of LV filling and in risk stratification of patients with dilated cardiomyopathy (DC). MATERIAL AND METHODS: We prospectively studied 32 consecutive patients, mean age 56.1 +/- 15.7 years, 22 (68.75%) male, mean ejection fraction 28.1 +/- 7.5%. All of them were in NYHA class < or = II and on ACE inhibitors. Eight (25%) were on beta-blockers. Patients without sinus rhythm, paced or with significant hypertensive, congenital or valvular heart disease were previously excluded. The following parameters of LV systolic function were assessed by echocardiography: fractional shortening, ejection fraction and cardiac output. LV filling was assessed by transmitral flow pulsed Doppler analysis: isovolumic relaxation time (IVRT), peak E and A wave velocities, E wave deceleration time (DT). We also evaluated a new Doppler index of combined systolic and diastolic myocardial performance (Tei index). PV (cm/s) was calculated by Color M-mode. Univariate regression analysis was performed (PV as dependent variable). RESULTS: We detected a high prevalence of diastolic function disturbances: 25 (78.1%) patients with a delayed relaxation pattern and only 3 (9.4%) with a restrictive pattern. PV did not correlate with age, body surface and LV geometry. There was a significant correlation between PV and E/A ratio (r = 0.61; p < 0.0001), IVRT (r = -0.50; p = 0.006), DT (r = -0.41; p = 0.01) and Tei index (r = -0.36; p = 0.04). CONCLUSIONS: Our results indicate that, in patients with a predominance of delayed relaxation, there is a strong relationship between PV and the classic parameters of LV filling. For similar levels of systolic impairment, PV could be an easy, fast and reproducible quantitative indicator of severity on DC.

Cardiomyopathy, Dilated↗
PubMed2001

A phase II study of weekly paclitaxel in elderly patients with advanced non-small cell lung cancer.

PURPOSE: Our aim was to evaluate the efficacy, toxicity, and pharmacokinetic behavior of single-agent paclitaxel given weekly to elderly patients with lung cancer. EXPERIMENTAL DESIGN: Previously untreated patients with stage IIIB/IV non-small cell lung cancer were eligible for the study if they were at least 70 years of age and had preserved organ function. Paclitaxel was administered over 1 h at a dose of 90 mg/m(2) for 6 consecutive weeks on an 8-week cycle. The pharmacokinetics of paclitaxel were assessed during the first and sixth week of therapy in a subgroup of eight patients. RESULTS: A total of 35 patients (median age, 76 years; range, 70-85) were enrolled. The overall response rate was 23%. Median time to failure was 5.2 months, whereas the median survival time was 10.3 months. Survival rates after 1 and 2 years were 45 and 22%, respectively. Grade 3/4 toxicities included neutropenia (5.8%), hyperglycemia (17.6%), neuropathy (5.8%), and infection (8.8%). Two patients died from treatment-related toxicity. There was no significant difference (P = 0.18) between the total body clearance of paclitaxel on the first (17.4 +/- 2.9 liters/h/m(2), mean +/- SD) and sixth (15.8 +/- 4.1 liters/h/m(2)) week of therapy. CONCLUSION: Paclitaxel administered as a weekly 1-h infusion at a dose of 90 mg/m(2) is a safe and effective therapy for elderly patients with advanced non-small cell lung cancer. Its pharmacokinetics in elderly patients do not appear to differ from historical data for younger patients, and there was no suggestion of a change in drug clearance after repeated weekly dosing.

Age Factors↗
PubMed2000

Mitochondrial DNA variants in inclusion body myositis.

Mitochondrial DNA variants have been shown to be associated with many diseases. Mutations at mitochondrial DNA nucleotide positions 3192, 3196, 3397 and 4336 have been described in association with late-onset Alzheimer's disease. The pathological similarities between inclusion body myositis and Alzheimer's disease prompted an analysis of the relationship between the reported mutations and sporadic inclusion body myositis. The 4336G variant was not significantly increased in patients with inclusion body myositis or Alzheimer's disease when compared to controls. None of the patients with inclusion body myositis carried mutations at nucleotide positions 3192, 3196 and 3397. A transition at nucleotide position 4580 was detected in some patients with inclusion body myositis and Alzheimer's disease but was not significantly higher in frequency when compared to controls. Phylogenetic analysis showed that the 4336G and 4580A variants clustered together in their respective group. A group of patients with inclusion body myositis also clustered together on a separate branch of the phylogenetic tree. Closer investigation of this group revealed a common polymorphism at nucleotide position 16311. The frequency of the 16311C variant was higher in inclusion body myositis than in Alzheimer's disease and controls, although when only caucasian patients were considered the increased frequency was not statistically significant. Further studies will be required to determine whether this variant plays a role in the pathogenesis of inclusion body myositis.

Adult↗
PubMed2000

[Isolated non-compaction of left ventricular myocardium].

Noncompaction of the ventricular myocardium, also known as "spongy myocardium", is a rare congenital abnormality resulting from an arrest in the normal endomyocardial embryogenesis. The echocardiographic findings consist of multiple, prominent myocardial trabeculations and deep intratrabecular recesses in communication with the left ventricular cavity. This entity is a not well known cause of dilated cardiomyopathy. Some cases were described as X-linked familial forms. We report the clinical case of a 13-year-old female patient with severe left ventricular disfunction, a very trabeculated left ventricle on echocardiography and two admissions in class IV heart failure.

Adolescent↗
PubMed2000

[Effect of programming different AV intervals on mitral insufficiency in patients with DDD pacemaker].

OBJECTIVE: To study the effect of programming three different atrioventricular intervals (AVI) on mitral insufficiency (MI) in patients with permanent pacemaker due to complete atrioventricular block. METHODS: We included 9 patients (mean age 62 +/- 11 years; 6 men), with permanent DDD pacemaker, isolated MI and normal ventricular function. We evaluated MI (in a quantitative way) and cardiac output (CO) through echocardiographic examination with three different AVI (100, 150 and 200 ms). RESULTS: We observed a reduction in the severity of MI with the reduction of the AVI (best results obtained with AVI of 100 ms). We also observed an increase in the CO in 4 patients (those with MI of greater degree) with AVI of 100 ms. CONCLUSIONS: We observed a correlation of longer AVI with greater degree of MI; our results point to the possibility of increasing the CO of patients with greater degrees of MI with shortening of the AVI (probably due to a partial recovery of the regurgitant volume).

Aged↗
PubMed1999

Alzheimer disease: curly fibers and tangles in organs other than brain.

The filamentous brain lesions that define Alzheimer disease (AD) consist of senile plaques and neurofibrillary tangles. Undulated pathological filaments--curly fibers or neuropil threads--also occur in the neuropil. Beta-amyloid precursor proteins are synthesized by many cells outside the central nervous system and recently, deposition of beta-amyloid-protein was reported to occur in non-neuronal tissues. In addition, increasing data claim the importance of chronic inflammation in the pathogenesis of AD. These observations suggest that AD may be a widespread systemic disorder. Here we report that pathological argyrophilic filaments with histochemical properties of amyloid showing striking morphological similarity to curly fibers and/or tangles accumulate not only in ependymal layer and in epithelial cells of choroid plexus, but also in several other organs (e.g. liver, pancreas, ovary, testis, thyroid) in AD. The ependyma, choroid plexus, and various organs of 39 autopsy cases were analyzed. In search of curly fiber and tangle-like changes in organs other than brain, 395 blocks from 21 different tissues of 24 AD cases, 5 cases with discrete or moderate AD-type changes, and 10 control cases were investigated. We found in non-neuronal cells "curly fibers" or "tangles" immunoreactive with antibodies to P component, Tau-protein, ubiquitin, fibronectin, and Apolipoprotein-E, but lacking immunoreactivity with antibodies to neurofilament proteins. Ultrastructurally they consist of densely packed straight and paired helical filaments and closely resemble neurofibrillary tangles and neuropil threads. These observations indicate that the formation of "curly fibers" and "tangles" is not unique to the central nervous system. The results suggest that AD might be a systemic disorder or that similar fibrillary changes to tangles and curly fibers may also be associated with other amyloidosis than beta-amyloidosis. Further investigations are necessary to understand the pathogenetic interest of these fibrillary changes outside the CNS.

Adult↗
PubMed1998

Decreased lumbar spine bone mass and low bone turnover in children and adolescents with insulin dependent diabetes mellitus followed longitudinally.

The effects of insulin dependent diabetes mellitus (IDDM) on bone metabolism are still not well defined. We evaluated total bone mineral content (TBMC) and bone mineral density (BMD) at the lumbar spine and femoral neck using dual X-ray absorptiometry in 26 IDDM children (15 M, 11 F) with a mean chronological age of 12.1+/-3.1 yr (range 7.1-14.2 yr). Duration of diabetes was 4.3+/-2.9 yr, with a mean glycosylated hemoglobin of 9.2+/-0.4%. BMD and TBMC standard deviation scores (Z-scores) were determined by comparing our results to controls matched for age, sex and pubertal status. BMD and bone formation and resorption markers were determined at the beginning of the study and after one year of follow up. Mean lumbar spine Z-score was -1.06+/-0.2, with negative values in 24 of 26 children (92.6%); 14/26 patients (53.8%) had a lumbar spine Z-score >1.0 SD below the mean. Mean lumbar spine Z-score remained unchanged after one year of follow up (-1.02+/-0.3). No significant differences were obtained in femoral neck BMD or TBMC between groups. No correlation was observed between lumbar spine BMD Z-scores and duration of IDDM or degree of diabetes control, as assessed by the mean glycosylated hemoglobin. Daily urinary calcium excretion was elevated in our patients initially and after one year of follow up; however, no correlation was obtained between lumbar spine BMD and 24 h urinary calcium excretion. Carboxy-terminal propeptide of type 1 collagen values and levels of urinary cross-linked N-telopeptides of type 1 collagen in the diabetic children were significantly lower than those of the matched controls. Osteoblastic activity as assessed by serum osteocalcin and by the carboxy-terminal propeptide of type I collagen and bone resorption as measured by cross-linked N-telopeptides of type 1 collagen did not correlate with the lumbar spine Z-scores. When IDDM patients were subdivided into males and females and into children with more than or less than 2 yr duration of diabetes since diagnosis, no differences between groups were found. These results suggest that insulin dependent diabetes in children is associated with low bone turnover resulting in a deficit in bone mass which may be manifested as osteopenia in the growing bone. This defect is already present in trabecular bone early on in the disease and seems not to be related to glycemic control.

Adolescent↗
PubMed1998

Epidemiological aspects of centipede (Scolopendromorphae: Chilopoda) bites registered in greater S. Paulo, SP, Brazil.

INTRODUCTION: The lack of basic knowledge on venomous arthropods and the benignity of the clinical manifestations contribute to the centipede bite victims' not being taken to a treatment reference center, leading to underestimation of the number of cases and minimizing the possibility of a broader epidemiological view. An inventory of the centipede bite occurrences in Greater S. Paulo, Brazil, and the therapeutic methods employed, by the main Brazilian medical center for the notification of poisoning by venomous animals, is presented. METHOD: All patient cards of the period 1980-1989 have been checked as to place, month and time of occurrence; sex, age, affected part of the body, signs and symptoms have been observed, as well as the therapeutic methods employed. The centipedes that caused the accidents were identified at the Arthropods Laboratory. RESULTS: It was registered 216 accidents, with a 69% predominance of the Greater S. Paulo and in only 63% of the cases (136) was the agent brought in by the victim for identification. The genera most frequently represented were Cryptops (58%), Otostigmus (33%) and Scolopendra (4%). Of the 136 cases, 87% showed erythema, edema, hemorrhage, burns, cephalalgia, and intense pain. There was a predominance of accidents in the warm rainy season, in the morning and for females between 21 and 60 years of age. Hands and feet were the parts of the body most affected. The benign evolution of the clinical picture (54%) made therapeutical treatment unnecessary. Only the victims of Scolopendra and Otostigmus (46%) were medicated with anesthetics (51%), analgesics (25%), antihistamines and cortisone (24%). CONCLUSION: The reproductive period of the centipedes, associated with their sinanthropic habits, contributes to the greater incidence of accidents in urban areas in the warm rainy season. Only patients bitten by Scolopendra and Otostigmus require therapeutical treatment.

Adult↗
PubMed1998

Genital manifestations of schistosomiasis mansoni in women: important but neglected.

Egg-induced lesions in the upper and the lower female reproductive tract are important complications of the infection with Schistosoma mansoni. The understanding of the pathophysiology and pathology of genital lesions is only rudimentary, simple and reliable diagnostic tools are not at hand, epidemiological data do not exist and how to treat best the women affected, is not known. In view of recent advances in the understanding of genital lesions induced by S. haematobium the existing literature is critically analyzed and possible consequences of female genital schistosomiasis are outlined. We estimate that 6 to 27% girls and women with intestinal schistosomiasis, at least temporarily, suffer from pathology induced by eggs sequestered somewhere in their genital organs. This is a matter of concern and warrants more research into the epidemiology, pathology, diagnosis and therapy of this disease entity.

Adolescent↗
PubMed1997

DYSBOT: a single-blind, randomized parallel study to determine whether any differences can be detected in the efficacy and tolerability of two formulations of botulinum toxin type A--Dysport and Botox--assuming a ratio of 4:1.

BACKGROUND: Elston and Russell discovered a difference in the biological potency of the English formulation of botulinum toxin type A or BTX-A (Dysport) and the American formulation (Botox). Potency of both is expressed in LD50 mouse units, but because of assay differences, these units are not equivalent. Since the first warning by Quinn and Hallet on the clinical importance of this issue, it has been impossible to reach a consensus on the conversion factor for the potency of these formulations. OBJECTIVE: To test the hypothesis that the conversion factor for the clinical potency of Dysport to Botox is approximately 4:1. DYSBOT is an acronym that results from adding "DYS" from Dysport with "BOT" from Botox. PATIENTS AND METHODS DESIGN: A single-blind, randomized, parallel comparison. A total of 91 patients with blepharospasm or hemifacial spasm were randomized to treatment with Dysport or Botox using a fixed potency ratio of 4:1. Clinical evaluations: The patients were evaluated at baseline (day of the treatment). 1 month after treatment, and whenever the effect was judged to be fading. Objective and functional rating scales were used as quantitative measures of the change in clinical status. Adverse reactions were collected using a systematic questionnaire. RESULTS: Using this ratio between products, both Dysport and Botox groups produced similar clinical efficacy and tolerability. For patients showing a positive response without the need of a booster, the duration of effect was 13.3 +/- 5.9 weeks for the Dysport group and 11.2 +/- 5.8 weeks for the Botox group. Of 48 patients, 11 (23%) needed booster treatment in the Dysport group compared with five (12%) of 43 in Botox group. Adverse events were noted in 24 (50%) of 48 patients in the Dysport group and 20 (47%) of 43 of the Botox-treated group. CONCLUSIONS: Using a 4:1 conversion ratio for Dysport and Botox, similar results were obtained for the two treatments in an appropriately powered study, suggesting that this conversion factor is a good estimate of their comparative clinical potencies.

Aged↗
PubMed1997

[Infections of cerebrospinal fluid shunts in children. Review of 100 infections in 87 children].

An analysis of 100 infections in 87 children treated with shunts in the period of 1982 to 1995 is reported. The clinical presentation has been more frequently secondary to inflammatory signals. Staphylococcus were the most frequently microorganisms found. Infection by Gram negative agents was more aggressive and directly related with failure of therapy. Treatment included since only systemic antibiotics until withdrawal of shunt with use of systemic and intrathecal antibiotics. The best therapeutic results were obtained with withdrawal of shunt system and replacement by external shunt system associated to systemic antibiotics. In our experience this management must be accepted for treatment of this severe complication.

Bacterial Infections↗
PubMed1997

[Mail questionnaires. A useful strategy for the follow-up of patients with a cerebrovascular stroke?].

Although not frequently used in Portugal, postal questionnaires allow the collection of information on patient's follow-up. In this study we assessed the rate of response and the usefulness of a postal questionnaire in a sample of patients with acute stroke. A prospective study was designed and analysed as a case-control: postal questionnaires were sent to 138 patients together with a randomly assigned stamped or post-free return envelope. The percentage of responders was 60% (n=78) and we found no significant differences in response rates according to the mailing strategy (58% for stamped and 62% for post-free return envelopes, p = 0.786). The time gap between hospital discharge and sending of the questionnaire had no significant influence in the response rate. Elder patients and women tend to respond more frequently, but these characteristics also do not change the response rate. Analysing socio-demographic variables reported at the acute phase, we only found differences in response rate for the smoking status: smoking was associated with a lower participation. In conclusion, the present study showed that a postal questionnaire is a useful method for the follow-up of stroke cases and that we must pay special attention to smokers for whom alternative strategies of contact or information should be used to increase compliance with postal questionnaire follow-up.

Aged↗
PubMed1996

Altered oxidation and signal transduction systems in fibroblasts from Alzheimer patients.

Abnormalities in calcium regulation, amyloid-beta-protein (A beta) production and oxidative metabolism have been implicated in Alzheimer's disease (AD). The use of cultured fibroblasts complement post-mortem and genetic approaches in clarifying the interaction of these processes and the underlying mechanism for the changes in AD. Definition of gene defects in particular Alzheimer families (FAD) permits elucidation of the role of those genetic abnormalities in altered signal transduction in cell lines from those families. Abnormalities in calcium regulation, ion channels, cyclic AMP, the phosphatidylinositide cascade and oxidative metabolism are well documented in fibroblasts from patients with primary genetic defects in the presenilins. Recent studies in AD fibroblasts that demonstrate abnormal secretion of A beta, a protein known to form the characteristic extracellular amyloid deposits in AD brain, further supports the use of these cells in AD research. Comparison of changes in calcium signaling, mitochondrial oxidation and A beta production in these cells suggests that changes in signal transduction including calcium may be a more consistent observation than altered A beta production in fibroblasts from some FAD families. An understanding of these abnormalities in fibroblasts may provide further insights into the pathophysiology of AD, new diagnostic measures and perhaps innovative therapeutic approaches.

Aging↗
PubMed1996

Short report: association between leprosy and hepatitis C infection: a survey in a region of central Brazil.

Prevalence of antibodies to hepatitis C virus (HCV) was determined in 216 Brazilian lepromatous patients (83 outpatients and 133 institutionalized). The overall prevalence was 1.8% after confirmatory tests. No difference in the HCV infection was found between outpatients and institutionalized ones. Our results from this region of Central Brazil are lower than those found in leprosy patients in Africa and in Japan.

Adolescent↗