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Biomedical subjects

A Miranda

Publications and source records attributed to A Miranda.

At least 37 records · Page 2Linked to original sources
PubMed2002

Stability study of flutamide in solid state and in aqueous solution.

A high-performance liquid chromatography (HPLC) assay has been developed for the determination of flutamide and its degradation products. Using this method, the influence of important formulation factors on the stability of flutamide has been estimated. The stability studies have been carried out in solid state as well as in aqueous solution. The results obtained have shown a good stability for flutamide in solid state. This drug remained practically unchanged after a four-month assay in adverse temperature and humidity conditions. On the other hand, the results obtained from the stability study in solution during 12 days have shown that flutamide in aqueous solution underwent a clear degradation at mean or high temperature (22 degrees C, 37 degrees C) and acidic pH conditions (1.1). With respect to the influence of ionic strength, it has been found that the presence of sodium chloride prevents the degradation of flutamide in aqueous solution. The second-order kinetics model provides the best fit for highly degraded solutions.

Analysis of Variance↗
PubMed2002

[Post-thyroidectomy hypocalcemia. Personal experience].

BACKGROUND: The study evaluates the incidence of both early and protracted post-thyroidectomy hypocalcemia over a 6-year period (1995-2000) in a series of 330 consecutive thryoid operations. The aim was to identify the profile of patients with the greatest risk of permanent parathyroid functional insufficiency and a suitable treatment protocol. METHODS: Having performed a statistical ana-lysis of all the variables, we divided the entire population of 330 patients into 4 groups based on the extent of demolition, the method of organotherapeutic replacement with L-Thyroxine and the (eco-radioguided) procedure used to identify the parathyroids: 59 patients undergoing subtotal thyroidectomy; 155 patients undergoing total thyroidectomy who commenced replacement organotherapy from postoperative day 15-30; 94 patients undergoing total thyroidectomy who commenced replacement organotherapy from postoperative day 1; 22 patients undergoing total thyroidectomy who underwent routine intraoperative parathyroid assay. RESULTS: The results show that the impact of more radical surgery in determining hypocalcemia, in particular protracted hypocalcemia, represents the most striking characteristic of patients with the greatest probability of permanent parathyroid insufficiency. We emphasise that early correction of postoperative hypothyroidism can drastically reduce the incidence of both early and protracted hypocalcemia. CONCLUSIONS: In conclusion, hypoparathyroidism is an exceptional event, whereas hypocalcemia is relatively common after total thyroidectomy. The effects of the early correction of postoperative hypothyroidism are undoubtedly beneficial, as is the use of eco- and radioguided methods for the intraoperative identification of the parathyroid glands, although they are not free from limits and criticism.

Adult↗
PubMed2002

[Factors modulating the efficacy of psychosocial treatment in children with attention deficit hyperactivity disorder].

INTRODUCTION: Treatment of patients with attention deficit hyperactivity disorder (ADHD) in recent decades has not been in one way only but rather by using various approaches (pharmacological, behavioural, cognitive, etc.). It is becoming increasingly obvious that hyperactivity requires a multi-disciplinary approach with clear instructions for parents and teachers. Teachers need most information regarding ADHD and its treatment so as to use the techniques which are most effective for directing behaviour in the classroom. OBJECTIVES: This study had two objectives. Firstly, we wished to analyze the efficacy of a psychosocial programme with multiple components (programme for individualized treatment in the classroom) in 50 children with ADHD using the methodology of significant clinical change analysis of Jacobson and Truax (1991). Secondly, to try to define the variables which may modulate cognition and behaviour and possibly affect the results and success or failure of the programme. DEVELOPMENT: Regarding the first objective, it was found that a much more significant proportion improved after following the hyperactivity/impulsivity programme, in the opinions of parents and teachers. Regarding the second objective the results show that the variables which may modulate the efficacy of treatment are deficits in inhibitory control, anxiety, disobedience, isolation and social inadaptation.

Attention Deficit Disorder with Hyperactivity↗
PubMed2001

Evaluation of the trifluoromethanosulfonic acid/trifluoroacetic acid/thioanisole cleavage procedure for application in solid-phase peptide synthesis.

As an extension of our investigation of peptidyl-resin linkage stability towards different cleavage procedures used in the solid-phase peptide synthesis (SPPS) technique, the present paper evaluated the trifluoromethanesulfonic acid (TFMSA)/trifluoroacetic acid (TFA)/thioanisole method, varying the type of resin (benzhydrylamine-resin, BHAR; methylbenzhydrylamine-resin, MBHAR and 4-(oxymethyl)-phenylacetamidomethyl-resin, PAMR) and peptide resin-bound residue (Gly and Phe). The vasoactive angiotensin II (AII, DRVYIHPF) and its [Gly8]-AII analogue linked to those resins used routinely in tert-butyloxycarbonyl (Boc)-SPPS chemistry were submitted comparatively to a time course study towards TFMSA/TFA cleavage. At 0 degrees C, [Gly8]-AII was completely removed from all resins in less than 6 h, but the hydrophobic Phe8 moiety-containing AII sequence was only partially cleaved (not more than 15%) from BHAR or MBHAR in this period. At 25 degrees C, [Gly8]-AII cleavage time decreased to less than 2 h irrespective of the solid support, and quantitative removal of AII from PAMR and MBHAR occurred in less than 3 h. However, about 10-15 h seemed to be necessary for cleavage of AII from BHAR, and in this extended cleavage reaction a significant increase in peptide degradation rate was observed. Regardless of the cleavage temperature used, the decreasing order of acid stability measured for resins was BHAR>MBHAR>PAMR. Collectively, these findings demonstrated the feasibility of applying TFMSA/TFA solution as a substitute for anhydrous HF at the cleavage step in Boc-SPPS methodology. Care should be taken however, as the cleavage efficacy depends on multiple factors including the resin, peptide sequence, the time and temperature of reaction.

Amino Acids↗
PubMed2000

An association study of bipolar mood disorder (type I) with the 5-HTTLPR serotonin transporter polymorphism in a human population isolate from Colombia.

The short variant of a functional length polymorphism in the promoter region of the serotonin transporter has been associated with several behavioural and psychiatric traits, including bipolar mood disorder. The same short allele has also been implicated as a modifier of the bipolar phenotype. Here we evaluate the etiologic/modifier role of this polymorphism in a case (N=103) / control (N=112) sample for bipolar mood disorder (type I) collected from an isolated South American population. We did not detect an association between bipolar disorder and the 5-HTT promoter polymorphism in this sample. However, an excess of the short allele was seen in younger cases and in cases with psychotic symptoms. When combined with data from the literature, the increased frequency of the short allele in patients with psychotic symptoms was statistically significant.

Age of Onset↗
PubMed2000

Liver cirrhosis is reverted by urokinase-type plasminogen activator gene therapy.

Liver cirrhosis represents a worldwide health problem and is a major cause of mortality. Cirrhosis is the result of extensive hepatocyte death and fibrosis induced by chronic alcohol abuse and hepatitis B and C viruses. Successful gene therapy approaches to this disease may require both reversal of fibrosis and stimulation of hepatocyte growth. Urokinase-type plasminogen activator (uPA) may serve this function, as it is an initiator of the matrix proteolysis cascade and induces hepatocyte growth factor expression. In a rat cirrhosis model, a single iv administration of a replication-deficient adenoviral vector encoding a nonsecreted form of human uPA resulted in high production of functional uPA protein in the liver. This led to induction of collagenase expression and reversal of fibrosis with concomitant hepatocyte and improved liver function. Thus, uPA gene therapy may be an effective strategy for treating cirrhosis in humans.

Animals↗
PubMed2000

The heterogeneity of choanomastigote-shaped trypanosomatids as analyzed by their kDNA minicircle size: taxonomic implicaitons.

The kDNA minicircle size was analyzed in 15 species of choanomastigote-shaped trypanosomatids and four main groups of species were identified: (1) "Crithidia" deanei, "C." desouzai and "Herpetomonas" roitmani, which presented the largest molecules (> or = 3,800 bp), (2) "C." oncopelti with minicircles of at least four different sizes within 1,300-2,650 bp, (3) C. fasciculata, C. guilhermei and C. luciliae, having at least two sizes of minicircle (2,650 bp and 3,000 bp) and (4) a heterogeneous group of species presenting minicircles of a single size, including several Crithidia spp. (having 1,600 bp or 1,700 bp minicircles) and two Proteomonas spp. presenting the smallest minicircles (about 1,500 bp). These results were compared with other observations and discussed from a taxonomic point of view.

Animals↗
PubMed1999

Antimicrobial activity of a bovine hemoglobin fragment in the tick Boophilus microplus.

Antifungal and antibacterial activities were detected in the hemolymph and gut contents of the cattle tick, Boophilus microplus. A peptide with antibacterial activity from the tick gut contents was purified to homogeneity by reversed-phase chromatography. The molecular mass of the purified peptide was 3,205.7 Da, measured by matrix-assisted laser desorption/ionization mass spectrometry. The amino acid sequence was obtained by Edman degradation and showed that the peptide was identical to a fragment of the bovine alpha-hemoglobin. A synthetic peptide based on the sequence obtained showed characterization data identical to those of the isolated material, confirming its structure. The synthetic peptide was active in micromolar concentrations against Gram-positive bacteria and fungi. These data led us to conclude that the antibacterial activity detected in tick gut contents is the result of enzymatic processing of a host protein, hemoglobin. This activity may be used by ticks as a defense against microorganisms.

Amino Acid Sequence↗
PubMed1999

Natural evolution of skin test sensitivity in patients allergic to beta-lactam antibiotics.

BACKGROUND: Subjects with immediate reactions to penicillins and positive skin test responses may lose sensitivity if penicillin is avoided. The longer the interval between the reaction and the skin test, the greater the likelihood of having a negative result. OBJECTIVE: We sought to study prospectively the evolution of skin test sensitivity in a group of subjects allergic to penicillin with positive skin test responses to different penicillin determinants. METHODS: Skin tests were performed with major and minor determinants of benzylpenicillin (BPO/MDM), amoxicillin (AX), and ampicillin at the initial evaluation and repeated 1, 3, and 5 years later if the responses were still positive. Subjects were divided into 2 groups. Group A consisted of patients with a positive skin test response to benzylpenicilloyl or minor determinant mixture, and group B consisted of those with a selective response to amoxicillin and good tolerance to benzylpenicillin. RESULTS: In group A (n = 31) after 1 year, 25 patients continued to have positive responses and 6 began to have negative responses; after 3 years, 18 continued to have positive responses, 5 began to have negative responses, and 2 were lost to follow-up; and after 5 years, 12 continued to have positive responses, 5 began to have negative responses, and 1 was lost to follow-up. In group B (n = 24) 12 had positive responses, and 12 had negative responses after 1 year; 6 had positive responses, 5 had negative responses, and 1 was lost to follow-up after 3 years; and no patients had positive responses, 5 had negative responses, and 1 was lost to follow-up after 5 years. Survival analysis showed significant differences between groups (log-rank test = 12.8; P <. 0003). CONCLUSION: Patients with a selective response to amoxicillin tended to lose sensitivity faster than those who responded to several penicillin determinants, supporting the existence of at least 2 distinct types of IgE response in patients allergic to beta-lactam.

Adult↗
PubMed1999

Riding the waves of change in health system material management: team building in times of uncertainty.

Within the health care industry, reorganization brings new challenges and opportunities for improving work-related processes. This article examines one Midwestern health system's response to the systemic change that may occur after restructuring. The consolidation of diverse and separate material management departments within one integrated material management division prompted a concerted team development and training effort. In this model, management and non-management staff worked collaboratively to achieve a unified work group that will continue to evolve and grow with the needs of the organization.

Group Processes↗
PubMed1999

[Psychopedagogic rehabilitation of learning disorders in school children].

In this paper we discuss the main contributions of the three theoretical perspectives of psychology--conductual, cognitive and socio-historical--of education when there are learning difficulties. Finally, we emphasize the inefficacy of interventions and the need for implication in both the cognitive and meta-cognitive problems, and the socio-effective and conductual problems of these students.

Child↗
PubMed1999

[Attention deficit hyperactivity disorders: current controversy regarding definition, epidemiology, etiology and treatment].

In this paper a review of the current literature is carried out to provide information of consensus and divergence points from the Scientific Community, about interesting questions in the hyperactivity disorder. The core and traditionally debated questions are boarded, including the concept, assessment, prognosis and etiology to finish up with the comment concerning the treatment approaches. It's a concluded that although there aren't definitive answers, the different approaches of conceptualization are getting closer, a better understanding of neurobiological disorder basis, and the need of facing its assessment and treatment from multidisciplinary and multi-methodological assumptions is taking place.

Attention Deficit Disorder with Hyperactivity↗