Phloroglucinols from anti-microbial deposit-resins of Australian stingless bees (Tetragonula carbonaria).

Stingless bees accumulate deposits of plant resins that are mixed with beeswax to produce propolis. Previous studies have reported anti-microbial constituents of stingless bee (Tetragonula carbonaria) propolis from East Australia, but several components remained to be characterized. In the search of natural products yet unreported for Australian propolis, four bee deposit-resins of T. carbonaria bees were analysed by gas and liquid chromatography mass spectrometry with accurate mass measurements. Ethanolic extracts of the deposit-resins were tested in vitro against Staphylococcus aureus ATCC 25983 and Pseudomonas aeruginosa ATCC 27853 by the agar diffusion method. Phloroglucinols, flavonoids and isoprenoids were identified in samples. The crude extracts showed strong anti-staphylococcal effects but were less active against the Gram-negative bacterium. The diagnostic data enabled the identification of markers that can be used for profiling other Australian propolis sources and to target the isolation of bioactive phloroglucinols in future studies against antibiotic resistant S. aureus strains.

In vitro antibacterial phenolic extracts from "sugarbag" pot-honeys of Australian stingless bees (Tetragonula carbonaria).

Australian stingless bee honeys have been shown to exert antioxidant and in vitro antimicrobial properties; however their bioactive factors remained unidentified. This study investigated the antibacterial properties of phenolic extracts from Tetragonula carbonaria honeys. Honeys were harvested from beehives in three sites of South East Australia. Liquid-liquid extractions yielded the phenolic concentrates, for analyses by liquid and gas chromatography mass spectrometry. Antibacterial assays were conducted against Staphylococcus aureus and Klebsiella pneumoniae by in vitro agar diffusion and broth dilution assays. The phenolic extracts averaged to 5.87 mg/100 g of raw honeys, and constituents were 3-phenyllactic acid, lumichrome, diglycosylflavonoids, norisoprenoids. The honeys did not contain methylglyoxal, dihydroxyacetone or phenolics characteristic of Leptospermum nectars. Hydrogen peroxide content amounted up to 155.8 µM in honeys. Beside the bactericidal effects of hydrogen peroxide at 760 µM, other antibacterial factors were the phenolic extracts of "sugarbag" honeys that were active at minimum bactericidal concentrations of 1.2-1.8 mg/mL.

Anti-staphylococcal activity of C-methyl flavanones from propolis of Australian stingless bees (Tetragonula carbonaria) and fruit resins of Corymbia torelliana (Myrtaceae).

Propolis of Australian stingless bees (Tetragonula carbonaria, Meliponini) originating from Corymbia torelliana (Myrtaceae) fruit resins was tested for its antimicrobial activities as well as its flavonoid contents. This study aimed at the isolation, structural elucidation and antibacterial testing of flavanones of C. torelliana fruit resins that are incorporated into stingless bee propolis. Flavanones of this study were elucidated by spectroscopic and spectrometric methods including UV, 1D and 2D NMR, EI-MS, ESI-MS and HR-MS. The results indicated known C-methylated flavanones namely, 1 (2S)-cryptostrobin, its regioisomer 2 (2S)- stroboponin, 3 (2S)- cryptostrobin 7-methyl ether, and 6 (2S)- desmethoxymatteucinol, and known flavanones 4 (2S)- pinostrobin and 5 (2S)- pinocembrin as markers for C. torelliana fruit resins and one propolis type. Ethanolic preparations of propolis were shown to be active against Staphylococcus aureus (ATCC 25923) and to a lesser extent against Pseudomonas aeruginosa (ATCC 27853). C. torelliana flavanones inhibited the growth of S. aureus therefore contributing to the antibacterial effects observed for Australian stingless bee propolis extracts.

Validation of fingernail fluoride concentration as a predictor of risk for dental fluorosis.

The aim of this study was to validate the use of fingernail fluoride concentrations at ages 2-7 years as predictors of the risk for developing dental fluorosis in the permanent dentition. Fifty-six children of both genders (10-15 years of age) had their incisors and premolars examined for dental fluorosis using the Thylstrup-Fejerskov index. Fingernail fluoride concentrations were obtained from previous studies when children were 2-7 years of age. Data were analyzed by unpaired t test, ANOVA, and Fisher's exact test when the fingernail fluoride concentrations were dichotomized (≤ 2 or >2 µg/g). Children with dental fluorosis had significantly higher fingernail fluoride concentrations than those without the condition, and the concentrations tended to increase with the severity of fluorosis (r(2) = 0.47, p < 0.0001). Using a fingernail fluoride concentration of 2 µg/g at ages 2-7 years as a threshold, this biomarker had high sensitivity (0.84) and moderate specificity (0.53) as a predictor for dental fluorosis. The high positive predictive value indicates that fingernail fluoride concentrations should be useful in public health research, since it has the potential to identify around 80% of children at risk of developing dental fluorosis.

Infección del torrente circulatorio en una unidad de neonatología de Medellín-Colombia, 2008-2009 / Bloodstream infection in a neonatology unit of Medellín-Colombia, 2008-2009

Bloodstream infection (BSI) is one of the main causes of sepsis and death in newborns. The relative importance of nosocomial and non-nosocomial agents in developing countries is not clear. We conducted a prospective study of newborns hospitalized with a first episode of BSI in order to classify it as early, late or nosocomial, describe the clinical and microbiological charateristics, and explore risk factors between hospital-acquired vs commu-nity-acquiered BSI (HA-BSI vs CA-BSI). Twenty-seven newborns with a first episode of BSI were identified. Streptococcus agalactiae and coagulase negative Staphylococcus were the main agents in CA-BSI and HA-BSI, respectively. The only significant intrinsic risk factor between HA-BSI and CA-BSI was gestational age. The frequent finding of S. agalactiae warrants routine screening and prophylaxis in pregnant women. The risk factors for HA-BSI were mostly extrinsic, and thus, susceptible of being modified.

La infección del torrente circulatorio (ITC) es una de las principales causas de sepsis y muerte neonatal. Su etiología en países en vía de desarrollo, entre agentes no nosocomiales vs nosocomiales no está suficientemente esclarecida. Estudio prospectivo que incluyó neonatos hospitalizados que presentaron un primer hemocultivo positivo, con el propósito de describir características clínicas, microbiológicas, clasificar la ITC en temprana, tardía y nosocomial, y explorar factores de riesgo entre ITC adquirida en la comunidad vs ITC adquirida en el hospital (ITC-AC vs ITC-AH). Se identificaron 27 neonatos con un primer episodio de ITC. Streptococcus agalactiae y Staphylococcus coagulasa negativa fueron los principales agentes en ITC-AC e ITC-AH, respectivamente. El factor de riesgo intrínseco que mostró una diferencia significativa entre ITC-AC vs. ITC-AH fue la edad gestacional. La presencia de S. agalactiae permite plantear el tamizaje y profilaxis a la gestante. Los factores de riesgo para ITC-AH fueron en su mayoría extrínsecos, es decir, susceptibles de ser modificados.

[Bloodstream infection in a neonatology unit of Medellín-Colombia, 2008-2009]. / Infección del torrente circulatorio en una unidad de neonatología de Medellín-Colombia, 2008-2009.

Bloodstream infection (BSI) is one of the main causes of sepsis and death in newborns. The relative importance of nosocomial and non-nosocomial agents in developing countries is not clear. We conducted a prospective study of newborns hospitalized with a first episode of BSI in order to classify it as early, late or nosocomial, describe the clinical and microbiological characteristics, and explore risk factors between hospital-acquired vs community-acquired BSI (HA-BSI vs CA-BSI). Twenty-seven newborns with a first episode of BSI were identified. Streptococcus agalactiae and coagulase negative Staphylococcus were the main agents in CA-BSI and HA-BSI, respectively. The only significant intrinsic risk factor between HA-BSI and CA-BSI was gestational age. The frequent finding of S. agalactiae warrants routine screening and prophylaxis in pregnant women. The risk factors for HA-BSI were mostly extrinsic, and thus, susceptible of being modified.

Histoplasmosis pulmonar: infección pulmonar primaría: histoplastoma / Pulmonary histoplasmosis: primary pulmonary infection: histoplasmoma

La histoplasmosis es una micosis de origen pulmonar primario, adquirida por vía inhalatoria. En la mayoría de los casos, la infección pasa inadvertida o se manifiesta por síntomas respiratorios leves. El histoplasmoma es una forma relativamente común de histoplasmosis pulmonar aguda, de aspecto nodular, generalmente acompañada de calcificación, la cual puede aumentar en tamaño y simular una neoplasia pulmonar. presenta un caso de un paciente inmunosuprimido con esta forma de micosis pulmonar.

Physico-chemical properties and degradability of non-woven hyaluronan benzylic esters as tissue engineering scaffolds.

The development of biocompatible materials which can be processed into three-dimensional scaffolds and the design of appropriate configurations in order to enable the cellular infiltration and proliferation is a major issue in the tissue engineering. The hyaluronan total benzyl ester (Hyaff 11) has been found to be suitable substrate to grow a variety of cell types. Since structural, physical, chemical and biological data can help for tailoring appropriate scaffold for tissue engineering, information on chemicophysical properties on degradability of hyaluronan total benzyl ester non-woven has been obtained. The thermal analysis, the evaluation of the surface chemical composition, the morphology, the mechanical behaviour and the swelling tests were carried out on these materials. The hyaluronan total benzyl ester non-woven showed a thermal stability up to 220 degrees C and the surface composition differed from that of the bulk for C-O and C-C contribution. No contaminant were detected. The non-woven swelled in culture medium. Moreover the mechanical tests showed that when submitted to a press treatment, the samples have best mechanical properties. The pressed Hyaff 11 non-woven undergoes degradation when exposed to DMEM. The frying and breaking of the fibres, a decrease of the mechanical properties and a molecular weight loss have been observed. First, the ester bond of the Hyaff 11 non-woven is hydrolysed and the benzylic alcohol is released and the low molecular weight values indicate that a cleavage of the polymer is promoted by the components of the culture medium. After 11 days, some fragments, constituted by hyaluronic acid with a molecular weight of 23,000 Da became soluble in the medium. No oligomer was detected.

Comparative investigation of the surface properties of commercial titanium dental implants. Part I: chemical composition.

The surfaces of five commercially available titanium implants (Brånemark Nobel Biocare, 3i ICE, 3i OSSEOTITE, ITI-TPS, and ITI-SLA) were compared by scanning electron microscopy, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectroscopy. All five implant types were screw-shaped and fabricated from commercially pure (cp) titanium, but their surface properties differed both as regards surface morphology and surface chemical composition. The macro- and microstructure of the implant surfaces were investigated by scanning electron microscopy. The surfaces chemical composition was determined using the surface-sensitive analytical techniques of X-ray photoelectron spectroscopy and time-of-flight secondary ion spectrometry. Surface topographies were found to reflect the type of mechanical/chemical fabrication procedures applied by the manufacturers. The titanium oxide (passive) layer thickness was similar (5-6 nm) and typical for oxide films grown at or near room temperature. A variety of elements and chemical compounds not related to the metal composition were found on some implant types. They ranged from inorganic material such as sodium chloride to specific organic compounds believed to be due to contamination during fabrication or storage. The experimental findings are believed to make a contribution to a better understanding of the interplay between industrial fabrication procedure and physico-chemical implant surface properties.

Surface and biological evaluation of hydroxyapatite-based coatings on titanium deposited by different techniques.

Hydroxyapatite coatings have been deposited on titanium cp by plasma spray, sol-gel, and sputtering techniques for dental implant applications. The latter two techniques are of current interest, as they allow coatings of micrometer dimensions to be deposited. Coating morphology, composition, and structure have been investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). All coatings were homogeneous and exhibited a rough morphology suitable for implant applications. The sputtered (after annealing), plasma spray, and sol-gel coatings all showed diffraction peaks corresponding to hydroxyapatite. The surface contaminants were observed to be different for the different coating types. The sputtered coatings were found to have a composition most similar to hydroxyapatite; the sol-gel deposits also showed a high concentration of hydroxyl ions. A discrepancy in the Ca/P ratio was observed for the plasma spray coatings, and a small concentration of carbonate ions was found in the sputter-deposited coatings. The in vitro cell-culture studies using MG63 osteoblast-like cells demonstrated the ability of cells to proliferate on the materials tested. The sol-gel coating promotes higher cell growth, greater alkaline phosphatase activity, and greater osteocalcin production compared to the sputtered and plasma-sprayed coatings.

Preparation and characterisation of titania/hydroxyapatite composite coatings obtained by sol-gel process.

In the present work a titania network encapsulating a hydroxyapatite particulate phase is proposed as a bioceramic composite coating. The coating on a titanium substrate was produced starting from a sol containing a mixture of titania colloidal particles and hydroxyapatite submicron particles using the dip-coating technique. The microstructure, the morphology and the surface chemical composition of the coating were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Adhesion tests were also performed. These analyses showed that the obtained coating was chemically clean, homogeneous, rough, porous, with a low thickness and well-defined phase composition as well as a good adhesion to the substrate.

Chemico-physical properties of hyaluronan-based sponges.

The aim of this study was to obtain information on the chemico-physical and surface properties of the hyaluronan total benzylic ester sponges to evaluate their stability, surface "cleanliness" and handling for the applications in the tissue engineering. The thermal analysis, the characterization of surface chemical composition and the swelling test were performed on these materials. Moreover, the morphological changes, the rheological behavior, and the molecular weight loss in function of the time were monitored when the sponges were incubated in cell culture medium. The results showed that the sponges were thermally stable up to 220 degrees C and the surface composition was different from that of the bulk for C-O contribution. No contaminants were detected. In culture medium, the samples swelled assuming the rheological properties of biopolymer gel. When the sponges were in contact with the culture medium, their molecular weight remained stable for the first day and a loss of 11% and 31% was recorded for samples removed from culture medium after 3 and 7 days, respectively. With the scanning electron microscopy analysis, the spongy structure appeared with open interconnecting pores. The micrographs related to the samples after incubation in culture medium showed that the degradation was evident on the surface after 1 day. The deterioration of the pore walls and the presence of craters increased with time and, after 3 days, the phenomena were present also in the section.

[Brain aging and calcium antagonist drugs. A preliminary open study with nimodipine]. / Invecchiamento cerebrale e farmaci calcio-antagonisti. Studio preliminare in aperto con la nimodipina.

Forty patients aged 65-80 with minor-medium signs of brain aging were treated for 6 months with daily 90 mg doses of nimodipine. Treatment was well tolerated in that the minor side effects reported by a few of the patients never required withdrawal of the drug. Treatment proved useful, as shown by a variety of mental tests, in 69.5% of cases. In 20% conditions remained unchanged and in 9.5% further deterioration was observed. The authors conclude that nimodipine may be considered a useful therapeutic resource for phenomena of brain aging.

[On the frequency of primary hepatic carcinoma in the sector of Venice from 1906 to 1988]. / Sulla frequenza del carcinoma epatico primitivo nel settorato di Venezia dal 1906 al 1988.

Of about 56000 autopsies carried out in Venice (between 1906 and 1988) there is a frequency 1.15% of hepatic primary carcinoma. In the pre-1946 period, the frequency is 0.59%, whereas in the post-1946 period it rises to 1.88%. There is a marked increase of cirrhosis related carcinoma, most notably in women. The main risk factors would appear to be alcohol and HBV. In the same period, there were 3 cases of hepatoblastoma (0.005%) and one case of hepatocellular carcinoma in early infancy.