Challenges in Application of Langmuir Monolayer Studies To Determine the Mechanisms of Bactericidal Activity of Ruthenium Complexes.

The effects induced by antibiotics on the bacterial membrane may be correlated with their bactericidal activity, and such molecular-level interactions can be probed with Langmuir monolayers representing the cell membrane. In this study, we investigated the interaction between [Ru(mcbtz)2(PPh3)2] (RuBTZ, mcbtz = 2-mercaptobenzothiazoline) and [Ru(mctz)2(PPh3)2] (RuCTZ, mctz = 2-mercaptothiazoline) with Langmuir monolayers of a lipid extract of Escherichia coli, an extract of lipopolysaccharides (LPSs), and a zwitterionic phospholipid, dioleoylphosphatidyl choline (DOPC). RuBTZ and RuCTZ had little effects on DOPC, which is consistent with their negligible toxicity toward mammalian cells that may be approximated by a zwitterionic monolayer. Also little were their effects on LPSs. In contrast, RuBTZ and RuCTZ induced expansion in the surface pressure isotherms and decreased the compressional modulus of the E. coli lipid extract. While the more hydrophobic RuBTZ seemed to affect the hydrophobic tails of the E. coli extract monolayer to a larger extent, according to polarization modulation infrared reflection absorption spectroscopy results, evidence of a stronger RuBTZ interaction could not be confirmed unequivocally. Therefore, the interaction with the E. coli cell membrane cannot be directly correlated with the observed higher bactericidal activity of RuBTZ, in comparison to that of RuCTZ. This appears to be a case in which Langmuir monolayer studies do not suffice to determine the mechanisms responsible for the bactericidal activity.

The Hall Technique 10 years on: Questions and answers.

It is ten years since the first paper on the Hall Technique was published in the British Dental Journal and almost 20 years since the technique first came to notice. Dr Norna Hall a (now retired) general dental practitioner from the north of Scotland had, for many years, been managing carious primary molar teeth by cementing preformed metal crowns over them, with no local anaesthesia, tooth preparation or carious tissue removal. This first report, a retrospective analysis of Dr Hall's treatments, caused controversy. How could simply sealing a carious lesion, with all the associated bacteria and decayed tissues, possibly be clinically successful? Since then, growing understanding that caries is essentially a biofilm driven disease rather than an infectious disease, explains why the Hall Technique, and other 'sealing in' carious lesion techniques, are successful. The intervening ten years has seen robust evidence from several randomised control trials that are either completed or underway. These have found the Hall Technique superior to comparator treatments, with success rates (no pain or infection) of 99% (UK study) and 100% (Germany) at one year, 98% and 93% over two years (UK and Germany) and 97% over five years (UK). The Hall Technique is now regarded as one of several biological management options for carious lesions in primary molars. This paper covers commonly asked questions about the Hall Technique and speculates on what lies ahead.

Plantas medicinais conhecidas na zona urbana de Cajueiro da Praia, Piauí, Nordeste do Brasil / Known medicinal plants found in the urban Cajueiro da Praia urban area, Piauí state, Northeast Brazil

RESUMO A utilização de plantas com fins medicinais para tratamento, cura e prevenção de doenças é considerada uma das mais antigas formas de prática medicinal da humanidade. O presente estudo teve como objetivo identificar as espécies de plantas medicinais usadas dentro da comunidade de Cajueiro da Praia, Piauí, bem como a parte da planta utilizada, o modo de preparo, a sua importância relativa, o valor de uso e o consenso em relação às propriedades terapêuticas das espécies citadas. Foram aplicadas 12 entrevistas semiestruturadas com especialistas locais indicados, utilizando o método de amostragem por “bola-de-neve” e a técnica de “turnê-guiada” para coleta das espécies citadas. Análises quantitativas tais como Valor de Uso, Importância Relativa e Fator de Consenso dos Informantes foram associadas à análises qualitativas. As coletas botânicas seguiram a metodologia usual. Foram citadas 43 espécies, distribuídas em 24 famílias botânicas, sendo Lamiaceae a mais representada em número de espécies (oito espécies), seguida de Euphorbiaceae, Fabaceae, Myrtaceae e Rutaceae (todas com três). Chenopodium ambrosioides L. (mastruz) obteve o maior valor de uso (VU=1,58), sendo portanto, a planta com elevado potencial de uso para a comunidade. Quanto ao uso terapêutico, observou-se que um maior número de espécies foi indicado no combate à gripe, seguido por má digestão. O IR demonstrou que planta mais versátil foi Chenopodium ambrosioides L. (mastruz), com IR=2, referido em cinco categorias de uso e o FCI apontou que os sistemas corporais que apresentam maior importância local são: sistema circulatório (FCI=0,57), seguido por lesões e consequências de causas externas (FCI=0,50), sistema endócrino (FCI=0,50) e respiratório (FCI=0,40). No âmbito geral, verificou-se que a diversidade de plantas medicinais conhecida e a obtenção das plantas na comunidade estudada sugerem uma correlação entre uso/conhecimento de plantas medicinais e disponibilidade das mesmas; que a flora medicinal é representada, em boa parte, por plantas exóticas cultivadas nos quintais e que a transmissão do conhecimento tradicional feito localmente e por via oral demonstra uma herança cultural na cidade.

ABSTRACT The use of medicinal plants for the purposes of treating, curing and preventing diseases is considered one of the oldest forms of humanity’s medical practices. This study aimed to identify the species of medicinal plants used in the Cajueiro da Praia community, Piauí state, the part of the plant used, the method of preparation, their relative importance, the use value and the consensus on the therapeutic properties of the species mentioned. 12 semi-structured interviews with indicated local experts were performed, using the “snow-ball” sampling method and the “guided tour” technique to collect the aforementioned species by a standardized method. Quantitative analyzes such as Use value, relative importance and informant consensus factor were performed alongside qualitative analyzes. 43 species belonging to 24 botanical families were cited, Lamiaceae being the most represented in number of species (eight species) followed by Euphorbiaceae, Fabaceae, Myrtaceae and Rutaceae (with three each). Chenopodium ambrosioides L. (mastruz) had the highest use value (UV = 1.58), and therefore was the plant with the highest potential for use by the community. For therapeutic use, it was observed that a greater number of species have been shown to combat influenza, followed by maldigestion. The RI showed that the most versatile plant was Chenopodium ambrosioides L. (mastruz) with RI = 2, found in five usage categories and the ICF pointed out that the bodily systems that have greater local importance are: the circulatory system (ICF = 0.57), followed by lesions and consequences by external causes (ICF = 0.50), the endocrine (ICF = 0.50), and the respiratory system (ICF = 0.40). Within the general framework, it was found that the diversity of known medicinal plants and plants obtained from the population studied, suggested a correlation between the use/knowledge of medicinal plants and the availability there of; the medicinal flora is largely represented by exotic plants that are grown in backyards andby the transmission of traditional knowledge made locally and orally demonstrates a cultural heritage in the city.

Correlation of [RuCl3(dppb)(VPy)] cytotoxicity with its effects on the cell membranes: an investigation using Langmuir monolayers as membrane models.

One of the major challenges in drug design is to identify compounds with potential toxicity toward target cells, preferably with molecular-level understanding of their mode of action. In this study, the antitumor property of a ruthenium complex, mer-[RuCl3(dppb)(VPy)] (dppb = 1,4-bis(diphenylphosphine)butane and VPy = 4-vinylpyridine) (RuVPy), was analyzed. Results showed that this compound led to a mortality rate of 50% of HEp-2 cell with 120 ± 10 µmol L(-1), indicating its high toxicity. Then, to prove if its mode of action is associated with its interaction with cell membranes, Langmuir monolayers were used as a membrane model. RuVPy had a strong effect on the surface pressure isotherms, especially on the elastic properties of both the zwitterionic dipalmitoylphosphatidylcholine (DPPC) and the negatively charged dipalmitoylphosphatidylglycerol (DPPG) phospholipids. These data were confirmed by polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS). In addition, interactions between the positive group from RuVPy and the phosphate group from the phospholipids were corroborated by density functional theory (DFT) calculations, allowing the determination of the Ru complex orientation at the air-water interface. Although possible contributions from receptors or other cell components cannot be discarded, the results reported here represent evidence for significant effects on the cell membranes which are probably associated with the high toxicity of RuVPy.

Vena cava thrombosis associated with nephrotic syndrome in the puerperal gestational cycle.

CONTEXT: The puerperal gestational cycle is accompanied by a state of physiological hypercoagulability. Thromboembolic phenomena may occur at this time. OBJECTIVE: To report on a clinic case involving a patient that presented a family history of thromboembolism and developed deep vein thrombosis in a lower limb and vena cava thrombosis during the puerperal gestational cycle, displaying nephrotic syndrome as the main complication. DESIGN: Case report.

Electrodiagnosis in compression neuropathies of the upper extremities.

Compression neuropathies may occur at several points along the course of a nerve. Electrodiagnostic studies are helpful in the evaluation of nerve compression. Nerve conduction studies are the most useful of these techniques in determining the site of compression. Compression neuropathies of the upper extremities are common, and a well planned study is important to localize the site of involvement and the severity of the nerve damage.

[Nutritional status of pre-school children of the semi-arid region of Bahia (Brazil): II--Vitamin A deficiency]. / Situação nutricional e alimentar de pré-escolares no semi-árido da Bahia (Brasil): II--hipovitaminose A.

A survey of 754 preschool children was undertaken in the urban areas of seven small towns of the semi-arid region of Bahia, Northeastern Brazil, to determine the prevalence of vitamin A deficiency, as well as its association with variables such as a age, family income, mother's schooling and dietary adequacy in vitamin A. Protein energy malnutrition and anemia were also studied and are reported separately. The clinical ophthalmological examination did not reveal any signs or symptoms of xerophthalmia amongst these children. In 563 children serum retinol was determined and the average value found was 20.3 micrograms/dl (SD = 10.8 micrograms/dl); the prevalence of deficient serum retinol (below 10.0 micrograms/dl) was of 15.3%. In all 7 localities studied, the prevalence of deficient retinol levels was above 5.0%, the criterion recommended by WHO for considering it a Public Health Problem. The distribution of serum retinol was similar between the sexes, but there was an age trend: the prevalence of deficient and low levels decreased with age. There was no association between deficient serum retinol and family income per capita or mother's education. Results from the 24 h food consumption survey revealed that only 8% of children had an adequate intake of vitamin A through the diet; 66% received less than 1/2 and 35% less than 1/4 of the recommended daily intake of vitamin A. Vitamin A deficiency should be considered a Public Health Problem in the region due to the high prevalence of deficient levels of serum retinol as well as the large dietary inadequacy.

Effect of vitamin A supplementation on diarrhoea and acute lower-respiratory-tract infections in young children in Brazil.

A beneficial effect of periodic vitamin A supplementation on childhood mortality has been demonstrated, but the effect on morbidity is less clear. We investigated the effect of vitamin A supplementation on diarrhoea and acute lower-respiratory-tract infections (ALRI) in children from northeastern Brazil in a randomised, double-blind, placebo-controlled community trial. 1240 children aged 6-48 months were assigned vitamin A or placebo every 4 months for 1 year. They were followed up at home three times a week, and data about the occurrence and severity of diarrhoea and ALRI were collected. Any child with cough and respiratory rate above 40 breaths per min was visited by a paediatrician. The overall incidence of diarrhoea episodes was significantly lower in the vitamin-A-supplemented group than in the placebo group (18.42 vs 19.58 x 10(-3) child-days; rate ratio 0.94 [95% Cl 0.90-0.98]). The benefit of supplementation was greater as regards severe episodes of diarrhoea; the incidence was 20% lower in the vitamin A group than in the placebo group (rate ratio 0.80 [0.65-0.98]). With the standard definition of diarrhoea (> or = 3 liquid or semi-liquid stools in 24 h) the effect of vitamin A on mean daily prevalence did not reach significance, but as the definition of diarrhoea was made more stringent (increasing number of stools per day), a significant benefit became apparent, reaching for diarrhoea with 6 or more liquid or semi-liquid stools in 24 h a 23% lower prevalence. We found no effect of vitamin A supplementation on the incidence of ALRI. The reduction in severity of diarrhoea may be the most important factor in the lowering of mortality by vitamin A supplementation.

Aneurisma de artéria renal / Renal artery aneurysm

Pacientes com história de hematúria devem ser submetidos a detalhado protocolo de investigaçäo para a obtençäo de um diagnóstico preciso. Assim, relatamos um caso de hematúria macroscópica e a seqüência de exames complementares que nos levaram ao diagnóstico desta patologia rara. Em uma breve revisäo de literatura, salientamos: classificaçäo (etiológica ou morfológica), diagnóstico, indicaçöes cirúrgicas e o tratamento (embolizaçäo ou cirúrgico). O diagnóstico de certeza é obtido através de arteriografia renal digital, após avaliaçäo morfológica do trato urinário (UGE e US renal) normal e a constataçäo de sangramento unilateral (cistoscopia)

[Renal artery aneurysm]. / Aneurisma de artéria renal.

Patients with haematuria should be submitted to deep investigative protocol, for a more accurate diagnosis. Thus, we report a case of macroscopic haematuria and the set of complementary examinations that led to the diagnosis of this rare pathological entity. The classification (etiological or morphological), diagnosis, surgical intervention indications and therefore the treatment (embolization or surgical) were pointed out. Accurate diagnosis is obtained through Renal Digitalis Arteriography after the morphological assessment of the normal urinary tract (UGE and renal US) and the evidence of unilateral bleeding (cystoscopy).