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Biomedical subjects

M A Gutierrez

Publications and source records attributed to M A Gutierrez.

At least 19 recordsLinked to original sources
PubMed2007

Multiscale representation for automatic identification of structures in medical images.

The identification of structures is a key step in several applications of medical imaging. In this work we propose a method for the identification of structures using a multiscale approach with inclusion of a priori information about the searched objects. After describing the image structures in the multiscale representation, a matching step determines which structure most likely corresponds to the target. Patterns are generated by previous application of the method to a set of images. We present a prototype for identifying structures in 2D images. A set of experiments was carried out to evaluate the prototype leading to encouraging results.

Humans↗
PubMed2005

Heparan sulfate levels in mucopolysaccharidoses and mucolipidoses.

Glycosaminoglycans are accumulated in both mucopolysaccharidoses (MPS) and mucolipidoses (ML). MPS I, II, III and VII and ML II and ML III patients cannot properly degrade heparan sulphate (HS). In spite of the importance of HS storage in the metabolic pathway in these diseases, blood and urine HS levels have not been determined systematically using a simple and economical method. Using a new ELISA method using anti-HS antibodies, HS concentrations in blood and urine were determined in MPS and ML II and ML III patients. HS concentrations were determined in 156 plasma samples from MPS I (n = 23), MPS II (n = 26), MPS III (n = 24), MPS IV (n = 62), MPS VI (n = 5), MPS VII (n = 5), ML II (n = 8) and ML III (n = 3), and 205 urine samples from MPS I (n = 33), MPS II (n = 33), MPS III (n = 30), MPS IV (n = 82), MPS VI (n = 7), MPS VII (n = 9), ML II (n = 8) and ML III (n = 3). The ELISA method used monoclonal antibodies against HS. MPS I, II, III and VII and ML II and III patients had significant elevation in plasma HS, compared to the age-matched controls (p < 0.0001). Eighty-three out of 89 (93.3%) of individual values in the above MPS types and ML were above the mean +2SD of the controls. In urine samples, 75% of individual values in patients with those types were above the mean +2SD of the controls. In contrast to the previous understanding of the HS metabolic pathway, plasma HS levels in all five MPS VI and 15% of MPS IV patients were elevated above the mean +2SD of the controls. These findings suggest that HS concentration determined by ELISA, especially in plasma, could be a helpful marker for detection of the most severe MPS I, II, III, VI and VII and ML II, distinguishing them from normal populations.

Adolescent↗
PubMed2005

Keratan sulphate levels in mucopolysaccharidoses and mucolipidoses.

The mucopolysaccharidoses (MPS) is characterized by accumulation of glycosaminoglycans (GAGs), and mucolipidosis (ML) by accumulation of GAGs and sphingolipids. Each type of MPS accumulates specific GAGs. The lysosomal enzymes N-acetylgalactosamine-6-sulphate sulphatase and beta-galactosidase involve the stepwise degradation of keratan sulphate (KS). Deficiency of these enzymes results in elevation of KS levels in the body fluids and in tissues, leading to MPS IV disease. In this study, we evaluated blood and urine KS levels in types of MPS and ML other than MPS IV. Eighty-five plasma samples came from MPS I (n = 18), MPS II (n = 28), MPS III (n = 20), MPS VI (n = 3), MPS VII (n = 5) and ML (n = 11) patients while 127 urine samples came from MPS I (n = 34), MPS II (n = 34), MPS III (n = 32), MPS VI (n = 7), MPS VII (n = 9) and ML (n = 11) patients. KS levels were determined using the ELISA method. Plasma KS levels varied with age in both control and patient populations. In all age groups, the mean values of plasma KS in MPS and ML patients were significantly higher than those in the age-matched controls. Plasma KS values in four newborn patients were above the mean + 2SD of the age-matched controls (mean, 41 ng/ml). Overall, 85.9% of individual values in non-type IV MPS and ML patients were above the mean + 2SD of the age-matched controls. For urine KS levels, 24.4% of individual values in patients were above the mean + 2SD of the age-matched controls. In conclusion, KS in blood is elevated in each type of non-type IV MPS examined, in contrast to the conventional understanding. This finding suggests that measurement of KS level provides a new diagnostic biomarker in a wide variety of mucopolysaccharidoses and mucolipidoses in addition to MPS IV.

Adolescent↗
PubMed2002

Dehydroepiandrosterone sulfate and growth axis hormones in patients with ischemic heart disease.

BACKGROUND: The present study aimed to determine whether decreases in dehydroepiandrosterone sulfate (DHEA-S) and growth axis components precede cardiovascular disease or are a consequence of it. METHODS: We measured the concentrations in serum of DHEA-S, ACTH, cortisol, growth hormone, insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 in 30 male controls and also in 37 male patients on days 0, 2, 5, 7 and 9 after suffering a myocardial infarction (MI). RESULTS: There was no significant variation in any of these parameters between the controls and the patients on day 0. However, we found a significant (p < 0.001) reduction in the DHEA-S concentrations of the patients between day 0 and subsequent days (days 2, 5, 7 and 9). CONCLUSION: We conclude that the decrease in DHEA-S in patients with MI is a consequence and not a cause of the disease.

Adrenocorticotropic Hormone↗
PubMed2000

A voxel-based investigation of regional cerebral blood flow abnormalities in obsessive-compulsive disorder using single photon emission computed tomography (SPECT).

Several functional imaging studies have reported abnormalities of the orbitofrontal and anterior cingulate cortices, striatum and thalamus in obsessive-compulsive disorder (OCD). These studies have often been limited by small patient samples and image analysis methods that rely on region-of-interest (ROI) approaches. We have assessed resting regional cerebral blood flow with 99mTc-ECD SPECT in 26 unmedicated OCD patients and 22 healthy control subjects using the voxel-based Statistical Parametric Mapping method for data analysis. We found a significantly reduced ECD uptake in OCD patients relative to the control subjects in the right lateral orbitofrontal cortex, and in the left dorsal anterior cingulate cortex (P<0.001 two-tailed, uncorrected for multiple comparisons). There were significant positive correlations in the OCD group between the ECD uptake in the left lateral orbitofrontal cortex and ratings for obsessive-compulsive symptoms (OCS), and between the ECD uptake in the right medial orbitofrontal cortex and the ratings for both OCS and depressive symptoms. There were also unpredicted significant ECD uptake increases in the cerebellum in OCD patients, as well as a negative correlation between posterior cingulate ECD uptake and OCS severity (P<0.05, corrected for multiple testing). These results implicate specific subregions of the orbitofrontal and anterior cingulate cortices in the pathophysiology of OCD, as well as suggesting the involvement of other areas not usually included in ROI-based imaging studies. With the incorporation of voxel-based methods and the use of large patient samples, rCBF-SPECT studies may continue to provide valuable information about the functional anatomy of OCD.

Adult↗
PubMed1999

Management of and counseling for psychotropic drug-induced sexual dysfunction.

Clinicians are increasingly faced with the need to identify, treat, and counsel patients regarding psychotropic drug-induced sexual dysfunction. Antipsychotic and antidepressant drugs have both rational mechanisms to explain their effects on sexual function and established literature documenting these effects. The agents have potential for causing decreased libido, delayed ejaculation, and anorgasmia. Management and counseling can be highly effective for patients taking these agents.

Counseling↗
PubMed1998

Comparison of egg-yolk protein hydrolysate and soyabean protein hydrolysate in terms of nitrogen utilization.

Egg-yolk protein hydrolysate (YPp) is an alternative protein source in formulas for infants with intolerance to cow's milk or soyabean protein, or for patients with intestinal disorders. However, the nutritional value of YPp has never been investigated. YPp was prepared by enzymic hydrolysis of delipidated yolk protein, which led to an average peptide length of 2.6 residues. Three experiments were performed. In Expt 1, we compared the intestinal absorption rate of YPp and soyabean protein hydrolysate (SPp) in rats. YPp and SPp solutions were injected into the duodenum of anaesthetized rats and blood samples were taken from the portal vein at 7, 15, 30, 60, and 120 min. A higher amino acid concentration in the serum of the YPp group demonstrated that YPp was absorbed faster than SPp. In Expt 2, the effects of dietary YPp and SPp on body-weight gain, protein efficiency ratio (PER) and feed efficiency ratio (FER) were determined. At the end of the experiment, body weight had increased in both groups, while PER and FER were significantly higher in rats fed on YPp. In Expt 3, to investigate the effects of dietary YPp and SPp on N metabolism, we determined the biological value and net protein utilization. Yolk protein was the reference protein. Biological value and net protein utilization values were very similar between animals fed on yolk protein and YPp diets, and significantly higher than in rats fed on the SPp diet. The present findings demonstrate that there is no adverse effect of hydrolysis of yolk protein on N utilization, and that the nutritive value of YPp is similar to that of yolk protein and superior to that of SPp.

Animals↗
PubMed1997

Factors affecting mortality of crossbred and exotic chickens kept under backyard systems in Yucatan, Mexico.

Chicken mortality was studied in 24 randomly selected smallholder flocks in one village in Yucatan, Mexico between July and December 1993. Each family received a package of 10 to 12 chicks of 3 weeks of age. Approximately half of the chicks were purebred and the remainder were crosses produced by mating exotic with local breeds. All smallholders were visited twice a week. Feeding and management (except vaccination and medication) were left to smallholders. Data were processed by Chi-square, Mantel-Haenzel test and survival analysis. Before reaching 140 days of age 43.2% of the birds died. The highest mortality was observed during the 113 to 140 days of age period and the lowest was in the period between 22 and 56 days of age. Of all birds, 10.5% died from coccidiosis and 7.6% from Marek's disease. Of the risk factors investigated only medication and genotype showed significant effects on mortality. The effect of genotype was significant up to 112 days of age (P < 0.05). Crossbred birds lived longer than purebred; independently, medicated birds lived longer than non-medicated birds.

Animal Husbandry↗
PubMed1996

Development and implementation of drug use evaluation (DUE) criteria for risperidone in an outpatient psychiatric setting.

Risperidone is a recently approved atypical antipsychotic that offers the advantages over existing typical antipsychotics of improved efficacy against negative symptoms and a decreased incidence of extrapyramidal side effects. However, risperidone is much more expensive than other antipsychotics. A drug use evaluation (DUE) was undertaken to assess the prescribing practices of risperidone in a large public adult psychiatric outpatient clinic. After a through literature review, criteria describing the appropriate prescribing of risperidone were approved after consultation with the medical staff. Criteria were developed to delineate appropriate patient selection, laboratory and clinical monitoring parameters, documentation, and outcome measures. After a chart review was conducted to evaluate existing prescribing practices, the criteria and results were presented to the medical staff and the appropriateness of the criteria were discussed. After 1 month, a second chart review was conducted to evaluate changes in prescribing practices in response to these criteria. Risperidone was prescribed to 44 patients in the outpatient clinic. Sixteen of these patients were resistant to treatment with traditional antipsychotics, 19 had developed intolerable extrapyramidal side effects during treatment with traditional antipsychotics, 10 had developed tardive dyskinesia, and 11 were noncompliant with other treatment regimens (some patients fell into more than one category). In 35 patients able to be evaluated for side effects, the most common were termed "activating side effects" and included restlessness, anxiety, insomnia, and unspecified activation. These side effects occurred in 9 patients. Another 5 patients developed extrapyramidal side effects and 3 patients developed a tremor. The initial chart review showed deficiencies in several areas, including laboratory and clinical monitoring and documentation. After presentation of these results to the staff, a second review was conducted; the results demonstrated improvements in many of the areas that were originally deficient. In conclusion, it was shown that the criteria developed had an overall positive impact on the appropriate prescribing of risperidone.

Adult↗
PubMed1995

Hypermedia patient data retrieval and presentation through WWW.

WWW can be a helpful tool for PACS and HIS data retrieval and presentation. The use of gateways to access both text and hypermedia databases (images and video) enables fetched data to be presented in virtually any computer system. WWW browsers provide a very friendly interface and require little training to operate. This paper presents a prototype that uses a SQL gateway for accessing relational patient databases. The dataset used here include text data from reports of diagnostic procedures as well as pointers to the corresponding images. Images can be displayed by the browsers' viewers.

Computer Communication Networks↗
PubMed1993

Integrating Hospital Information Systems. The challenges and advantages of (re-)starting now.

With the new technologies available today, more complex and useful Hospital Information Systems (HIS) can be designed and implemented. These new technologies have allowed that information from different sources and nature such as documents, images and signals be integrated within a single environment. Open standards, reliable networks, powerful hardware and software and lower prices are among the issues that make all this possible. One of the main issues is what to do with old systems that do not adhere to this new HIS concept. At the Heart Institute (InCor), a decision was made towards starting developing a new system called I3S. This paper gives a brief description of that system.

Brazil↗
PubMed1991

Fluoroquinolones in the treatment of typhoid fever and the carrier state.

Typhoid fever remains an important public health problem throughout the world with a higher morbidity and mortality rate in the developing countries. Early establishment of the diagnosis and prompt initiation of treatment with chloramphenicol, ampicillin or trimethoprim-sulfamethoxazole is not necessarily followed by complete resolution of the infection. Between 1% and 6% of patients with typhoid fever become chronic biliary carriers of Salmonella typhi. These carriers are potential factors in the continued transmission of the disease. The increasing emergence worldwide of strains showing multiple resistance to the agents traditionally used in therapy has encouraged investigators to seek alternatives such as third generation cephalosporins and recently the new 4-quinolones, which have greater activity against Salmonella typhi including multi-resistant strains. The fluoroquinolones seem to be the treatment of choice in those regions where resistant strains of Salmonella typhi are prevalent.

4-Quinolones↗
PubMed1991

Acute traumatic midbrain hemorrhage: experimental and clinical observations with CT.

Traumatic brain stem hemorrhage (TBH) after blunt head impact is an uncommon injury and has historically been associated with high mortality. Retrospective clinical review identified 64 patients with TBH admitted during a 5-year period. Complete imaging and clinical records for 45 of these patients demonstrated that TBH could be categorized into three groups. The most frequent site of hemorrhage, in 31 (69%) of 45 patients (group 1), was the midline rostral anterior brain stem, posterior to the interpeduncular cistern, and this injury was associated with a 71% survival rate. This pattern was also associated with a predominantly anterior site of head and/or face impact. Eight (18%) patients (group 2) had miscellaneous foci of acute brain stem hemorrhage with seven (88%) surviving. Six (13%) patients (group 3) had brain stem hemorrhage associated with transtentorial herniation and brain stem compression, with 100% mortality. Experimental findings in a canine model and clinical results indicate that the anterior rostral midbrain is a common site of TBH and appears to arise from sudden craniocaudal displacement of the brain at impact. Survival is unexpected high with this location of traumatic midbrain hemorrhage.

Acute Disease↗