Medical Express

ISSN (print): 2318-8111

ISSN (online): 2358-0429

Issue: 2(5)2015 - 7 Articles


1 - Clinical pharmacology of gentamicin in neonates: regimen, toxicology and pharmacokinetics

Gian Maria Pacifici

MEDICALEXPRESS 2015;2(5):M150501

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Gentamicin is an aminoglycoside antibiotic. It kills bacteria by inhibiting protein synthesis and to some extent by lysing the cell envelope. Gentamicin is frequently the first choice drug because of its reliability, but also because of the long experience with its use. In combination with β-lactam antibiotics it is recommended for the treatment of sepsis or pneumonia and is active against P. aeruginosa, Enterobacter, Klebsiella and Serratia. However, gentamicin is ototoxic and nephrotoxic. The human mitochondrial genetic variant m.1555A > G has been reported to be an important cause of non-syndromic hereditary hearing dysfunction and may cause permanent hearing loss. Even short courses of gentamicin therapy in healty newborn infants can lead to abnormalities of auditory function. It is active against very resistant bacteria at peak concentrations (> 10 mg/l) that are high enough to be potentially toxic. For safe therapeutic efficacy, peak plasma concentrations of gentamicin should range from 4 to 10 mg/l; but trough concentrations, immediately before a new drug administration, must be lower that 2 mg/L to avoid toxic effects. Pharmacokinetic parameters vary considerably in infants. Half-life ranges from 5.4 to 10.0 hours, clearance 0.50 to 1.71 ml/h/kg and distribution volume from 0.4 to 0.7 l/kg. Preterm infants have a longer half-life than full-term infants. Thus, it is mandatory to monitor gentamicin serum concentrations whenever infants are treated for 48 hours or more.

Keywords: Gentamicin; Neonate; Nephrotoxicity; Ototoxicity; Pharmacokinetics, Toxicity.


2 - Hyposalivation, acidic saliva, decayed teeth and oral yeast prevalence in children with mucopolysaccharidosis

Sara Ponciano; Cristina Areias; Elisa Leão-Teles; Benedita Sampaio-Maia

MEDICALEXPRESS 2015;2(5):M150502

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OBJECTIVE: Patients with mucopolysaccharidosis present several alterations of the stomatognathic complex, however, no data is available on saliva biochemistry and yeast colonization. The aim of the study was to evaluate caries experience as well as saliva biochemistry and microbiology parameters in patients with mucopolysaccharidosis.
METHOD: The sample consisted of twelve participants with mucopolysaccharidosis followed in the Metabolic Disease Unit of the Centro Hospitalar de S. João and twelve healthy participants followed at the Faculty of Dental Medicine, University of Porto. To all participants, Decayed, Missing, Filled Teeth (DMFT) index was evaluated. In addition, saliva was collected to evaluate biochemical parameters (flow rate, pH, sodium, potassium, chloride, calcium, phosphate, α-amylase and IgA) and the microbiological profile (total microorganisms, mutans streptococci and yeasts) of all participants.
RESULTS: In comparison to controls, the mucoplysacharidosis patients presented a higher prevalence of decayed teeth, lower salivary flow and pH values. They also presented also lower calcium and higher phosphate ions in saliva. No differences were found between groups regarding oral microbial load for total microorganisms, mutans streptococci and yeasts as well as oral prevalence of mutans streptococci. However, MPS patients presented higher prevalence of oral Candida in comparison to controls.
CONCLUSION: The higher prevalence of decayed teeth and higher oral yeast colonization in MPS patients may be related to the lower saliva calcium concentration, pH and flow.

Keywords: mucopolysaccharidosis; oral health; pediatrics; candida, salivary pH.

3 - Effects of a transdermal testosterone metered-dose nanoemulsion in peri- and postmenopausal women: a novel protocol for treating low libido

Marco Antonio Botelho; Dinalva Brito Queiroz; Celso Felício Carvalho; Allan Freitas; Gisele Barros; Julia Gouvea; Lia Patrus; Mariane Bannet; Amália Cinthia Rego; Irami Araújo-Filho; Ivaldo Silva

MEDICALEXPRESS 2015;2(5):M150503

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OBJECTIVE: To investigate the efficacy of a transdermal nanoemulsion testosterone associated with transdermal estrogen therapy as a novel protocol treatment for emergent loss of libido.
METHODS: Twenty-four women, aged 31-75 years (mean age, 51.7), with emergent loss of libido were allocated to treatment with a novel transdermal formulation of 500 µg/day of testosterone (Biolipid/B2®-testosterone) for 12 weeks, as part of an open label prospective study on peri- and post-menopausal women. Subjects applied the formulation on the right forearm. Clinical and laboratorial parameters including the sexual complaints; serum concentrations of testosterone, insulin, C-reactive protein, weight, blood pressure; body mass index and waist circumference were compared between baseline and 12 weeks after treatment.
RESULTS: The mean total serum testosterone increased significantly (p = 0.009) after 12 weeks of treatment. No adverse or androgenic events were observed. There were positive and significant differences (p < 0.05) on sexual complaints, blood pressure, body mass index and waist circumference after transdermal nanoemulsion testosterone treatment.
CONCLUSION: This protocol is effective in increasing testosterone levels in peri- and postmenopausal women with low libido.

Keywords: androgen deficiency; menopause; nanotechnology; transdermal delivery; testosterone; nanoparticles.

4 - Globally chaotic analysis of Heart Rate Variability during acute auditory stimulus by heavy metal music

Marcela Leme Nogueira; David M. Garner; Elaine Osório; Luiz Carlos de Abreu; Vitor Engrácia Valenti

MEDICALEXPRESS 2015;2(5):M150504

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OBJECTIVE: Auditory stimulation with relaxing style music can improve cardiac autonomic regulation in subjects treated with a cardio-toxic medication. We assess the acute effect of heavy metal music on cardiac autonomic regulation, through novel high spectral chaotic global analysis techniques: (a) high spectral detrended fluctuation, (b) high spectral entropy (c) spectral multi-taper method.
METHOD: We investigated young adult women between 18 and 30 years old exposed to heavy metal (75-84 dB) music for 20 min. Normality tests were applied: (i) Anderson-Darling, (ii) Ryan-Joiner (similar to Shapiro-Wilk); (iii) Lilliefors for low number of subjects. They all indicated a non-normal data distribution. Consequently we applied the Kruskal-Wallis non-parametric test. Also because of the small population, we used a broader than usual level of significance (critical p = 0.1).
RESULTS: The application of the three tests for normality and the non-parametric test of significance by the Kruskal-Wallis technique showed that acute musical auditory stimulation with heavy metal music lead to a significant increase (p < 0.07) in one of the seven combinations of chaotic globals. The most significant combination of chaotic globals is the Chaos Forward Parameter One (CFP1), which includes all three studied chaotic globals (high spectral detrended fluctuation, high spectral entropy, spectral multi-taper method). We found significantly increased values during musical auditory stimulation for this specific CFP1.
CONLCUSION: It is suggested that acute musical stimulation with heavy metal influences cardiac autonomic regulation at a more complex level than previously reported and that this may be beneficial to heart function.

Keywords: Cardiovascular system; Autonomic nervous system; Auditory; Acoustic stimulation; High spectral chaotic globals.

5 - The impact of interleukin-13 receptor expressions in cell migration of astrocytomas

Isabele Fattori Moretti; Roseli Silva; Sueli Mieko Oba-Shinjo; Priscila Oliveira de Carvalho; Lais Cavalca Cardoso; Isac de Castro; Suely Kazue Nagahashi Marie

MEDICALEXPRESS 2015;2(5):M150505

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INTRODUCTION: Astrocytomas are common brain tumors. Increased expression levels of Interleukin-13 Receptor α2 (IL-13RA2) have been reported in astrocytomas. The Interleukin-13 signaling pathway may be associated with cell migration when binding to Interleukin-13 Receptor α1.
OBJECTIVE: To investigate Interleukin-13 Receptor α1 (IL-13RA1) and IL13RA2 expression levels in human diffusely infiltrative astrocytomas and test the involvement of Interleukin-13 levels in cell migration in two glioblastoma cell lines.
METHODS: IL13RA expression levels were accessed by quantitative real time PCR in 128 samples of astrocytomas and 18 samples of non-neoplastic brain tissues from temporal lobe epilepsy surgery. The impact of IL-13 levels (10 and 20 ng/mL) on cell migration was analyzed by the wound assay in U87MG and A172 cells.
RESULTS: Glioblastoma presented higher IL13RA1 and IL13RA2 expression levels compared to lower grades astrocytomas and to non-neoplastic cases. U87MG and A172 cells presented higher expression levels of IL-13RA1 vs. IL-13RA2. A significant difference in migration rate was observed in A172 cells treated with 10 ng/mL of IL-13 vs. control: treated cells presented slower migration than non-treated cells. U87MG cells treated with IL-13 20ng/mL presented slower migration than non-treated cells. This indicates that the IL13Rα1 signaling pathway was not activated, indeed inhibited by the decoy IL-13Rα2, slowing cell migration. This impact occurred with a lesser concentration of IL-13 on the A172 than on the U87MG cell line, because A172 cells have a higher IL-13RA2/A1 ratio.
CONCLUSION: The present results suggest IL-13 receptors as possible targets to decrease tumor cell migration.

Keywords: Astrocytoma; Interleukin-13; Interleukin-13 Receptors.

6 - The biochemistry of saliva throughout pregnancy

Rute Rio; Álvaro Azevedo; Liliana Simões-Silva; Jorge Marinho; Mário Jorge Silva; Benedita Sampaio-Maia

MEDICALEXPRESS 2015;2(5):M150506

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BACKGROUND & OBJECTIVE: Sialometric and sialochemical analyses during pregnancy are not consistent, and frequently contradictory in terms of salivary flow rate, pH, and concentration of calcium, phosphorous, sodium, potassium, chloride, glucose and α-amylase. We, therefore, measured the evolution of these parameters throughout pregnancy.
METHOD: A cross-sectional study compared sialometric and sialochemical analyses of 30 pregnant women vs. 30 age-matched non-pregnant women, and a longitudinal study evaluated the pregnant women in the first and third trimester of pregnancy.
RESULTS: Pregnant women presented acidic non-stimulated saliva, but neutral stimulated saliva pH, and no relevant changes in salivary flow rate. Scialochemical analysis showed decreased calcium levels, increased phosphate levels, and a progressive decrease in glucose levels throughout pregnancy.
CONCLUSION: Pregnancy significantly changes the oral biochemical milieu, creating a favorable environment for the development of oral pathology, in particular, dental caries.

Keywords: Saliva; pregnancy; pH; calcium; phosphorous; glucose


7 - MEDICALEXPRESS has been accepted for inclusion in SciELO and LILACS

Mauricio Rocha-e-Silva

MEDICALEXPRESS 2015;2(5):M150507