Complete Blood Count Collected Via Venipuncture Versus Peripherally Inserted Central Catheter in Hematological Patients: A Comparison of 2 Methods.

BACKGROUND: The use of peripherally inserted central catheters (PICCs) in cancer care is increasing over traditional central venous catheters. Nurses frequently collect blood by venipuncture when a PICC is inserted, as there is no available evidence to confirm the reliability of blood tests collected through PICCs in adults. OBJECTIVE: The aim of this study was to assess the reliability of blood samples for complete blood count (CBC) obtained through PICCs as an alternative to venipuncture. METHODS: A cross-sectional design was used to recruit adult hematological patients. The blood samples were collected within 5 minutes of each other by a specialist nurse. Hemoglobin, hematocrit, and platelet count were evaluated. To determine method comparison, Passing-Bablok regression, test of linearity, Pearson product-moment correlation coefficient, and Bland-Altman plots were used. RESULTS: Thirty paired blood samples were collected in 29 hematological patients with a mean age of 66.8 years. A statistical difference was found for hemoglobin (P = .001) and hematocrit (P = .001) levels, but no clinical difference. The regression models revealed no systematic differences and no proportional differences with a linear relationship between the methods. Bland-Altman plots highlighted a good agreement between methods. CONCLUSION: Blood samples for CBC drawn by PICCs are as reliable as those collected via venipuncture. Blood sampling via PICC could be recommended in people with hematological malignancies in needs of frequent blood tests. IMPLICATIONS FOR PRACTICE: Sampling through a PICC provides reliable laboratory results for CBC, and it could reduce patients' discomfort and increase the safety of professionals reducing the risk of accidental percutaneous needlestick injuries.

Ciprofloxacin-intercalated layered double hydroxide-in-hybrid films as composite dressings for controlled antimicrobial topical delivery.

Films based on biopolymers and loaded with antimicrobial agents are convenient pharmaceutical dosage forms for topical application. Inorganic carriers loaded with these agents lead to composite materials, which combined with polymers produce further functionality. Here, hybrid composite films based on layered double hydroxide (LDH) and hyaluronan (HS) as ciprofloxacin (Cip) delivery systems were studied as an alternative for prophylaxis and treatment of opportunistic infections in wounds. Cip-intercalated Zn-Al LDH (LDH-Cip), with high drug loading and crystallinity, were obtained by a precipitation at variable pH method, and then included in a HS dispersion for obtaining the hybrid composite films by solvent casting. Physicochemical characterization of films showed that a composite material where the HS acted as matrix and LDH-Cip aggregates acted as filler were obtained. LDH-Cip were uniformly dispersed along the (LDH-Cip)/HS films, which exhibited roughness in their surface, increasing their swelling capacity in PBS pH = 5.8. Controlled releases of Cip toward PBS at pH = 5.8 and 7.4 were obtained, and the best fits for the release profiles were found with Higuchi and Korsmeyer-Peppas models, respectively. (LDH-Cip)/HS films exhibited antimicrobial activity against S. aureus. These films would then provide sustained release of Cip after topical administration, maintaining a suitable level of antibacterial activity, combined with the wound healing properties of the HS. The interesting properties shown by the (LDH-Cip)/HS films make them a promising alternative for application in skin wounds.

A simple surface biofunctionalization strategy to inhibit the biofilm formation by Staphylococcus aureus on solid substrates.

Staphylococcus aureus is an important opportunistic pathogen that causes a broad range of infections due to the bacteria capacity to form biofilms on medical devices. This work is aimed at inhibiting the biofilm formation by S. aureus on solid substrates using a simple surface biofunctionalization strategy. We previously found that surface biofunctionalization with structural perturbed albumin inhibited the initial stage of S. aureus adhesion. The current work extends this strategy with other plasma protein, fibrinogen, which in addition can be bond specifically to the cell wall-anchored proteins of S. aureus. The study of fibrinogen adsorption indicates that the fraction of surface-perturbed molecules is enlarged at long adsorption times and low protein concentration. In these conditions, a significant diminution of ca.60% of alive adhered bacteria were observed after 40 min and the biofilm formation was completely prevented. Thus, it seems that the inhibition of bacterial adhesion on substrates with surface-perturbed proteins represents a general trend even when specific interactions are present. On this basis, we developed a simple strategy to inhibit the formation of S. aureus biofilm, using thermally treated albumin or fibrinogen molecules prior to the substrate biofunctionalization. This strategy shows an excellent performance since the alive adhered bacteria diminishes ca. 90% at short incubation time, followed by the fully inhibition of biofilm formation. This novel and simple resource represents a change of the usual notion in avoiding post-surgery infections, mostly related to the use of medical devices.

A Patient with Graves' Disease Scheduled for Thyroidectomy with High Risk for Thyroid Storm Caused by Severe Medication Nonadherence: Anaesthetic and Surgical Considerations.

In patients with failed hormone regulation who are scheduled for indispensable total thyroidectomy, the risk of thyroid storm with severe end-organ complications has to be anticipated. This case report presents the successful surgical and anaesthesiological management of a patient with Graves' disease, without any signs of perioperative thyroid storm. Possible recommendations for treatment are presented.

Albumin biofunctionalization to minimize the Staphylococcus aureus adhesion on solid substrates.

Staphylococcus aureus has become the most common opportunistic microorganism related to nosocomial infections due to the bacteria capacity to form biofilms on biomedical devices and implants. Since bacterial adhesion is the first step in this pathogenesis, it is evident that inhibiting such a process will reduce the opportunity for bacterial colonization on the devices. This work is aimed at optimizing a surface biofunctionalization strategy to inhibit the adhesion of S. aureus on solid substrates. The first part of the work deals with the albumin adsorption-desorption process, studied by a factorial design of experiments to explore a wide range of experimental factors (protein concentration, pH, flow rate and adsorption time) and responses (initial adsorption rate, adsorbed amount, desorbed extent) for hydrophilic and hydrophobic substrates, with a reduced number of experiments. This approach allows the simultaneous evaluation of the factors affecting the albumin adsorption-desorption process to find a qualitative correlation with the amount of alive S. aureus adhered on albumin biofunctionalized substrates. The results of this work point to a relationship between bacterial adhesion and the degree of albumin relaxation on the solid substrate. In fact, the inhibition of bacterial adhesion on albumin biofunctionalized substrates is due to the surface perturbation on the native structure of the protein. On this base, a biofunctionalization strategy was designed using a solution of thermally treated albumin molecules (higher ß-sheet or unordered secondary structure elements) to biofunctionalize solid substrates by dipping. With these albumin biofunctionalized substrates S. aureus adhesion was minimized.

Unaffected features of BSA stabilized Ag nanoparticles after storage and reconstitution in biological relevant media.

Silver-coated orthopedic implants and silver composite materials have been proposed to produce local biocidal activity at low dose to reduce post-surgery infection that remains one of the major contributions to the patient morbidity. This work presents the synthesis combined with the characterization, colloidal stability in biological relevant media, antimicrobial activity and handling properties of silver nanoparticles (Ag-NP) before and after freeze dry and storage. The nanomaterial was synthesized in aqueous solution with simple, reproducible and low-cost strategies using bovine serum albumin (BSA) as the stabilizing agent. Ag-NP were characterized by means of the size distribution and morphology (UV-vis spectra, dynamic light scattering measurements and TEM images), charge as a function of the pH (zeta potential measurements) and colloidal stability in biological relevant media (UV-vis spectra and dynamic light scattering measurements). Further, the interactions between the protein and Ag-NP were evaluated by surface enhanced Raman spectroscopy (SERS) and the antimicrobial activity was tested with two bacteria strains (namely Staphylococcus aureus and Staphylococcus epidermidis) mainly present in the infections caused by implants and prosthesis in orthopedic surgery. Finally, the Ag-NP dispersed in aqueous solution were dried and stored as long-lasting powders that were easily reconstituted without losing their stability and antimicrobial properties. The proposed methods to stabilize Ag-NP not only produce stable dispersions in media of biological relevance but also long-lasting powders with optimal antimicrobial activity in the nanomolar range. This level is much lower than the cytotoxicity determined in vitro on osteoblasts, osteoclasts and osteoarthritic chondrocytes. The synthesized Ag-NP can be incorporated as additive of biomaterials or pharmaceutical products to confer antimicrobial activity in a powdered form in different formulations, dispersed in aqueous and non-aqueous solutions or coated on the surface of different materials.

Factores de riesgo sexual y parenteral en los encuestados durante la campaña contra hepatitis virales 2013, Rosario, Argentina / Sexual and parenteral risk factors in subjects surveyed during a campaign against viral hepatitis (2013), Rosario, Argentina

La enfermedad hepática viral constituye un problema y un desafío para los médicos y sus pacientes. En agosto de 2013 en la ciudad de Rosario se efectuó la Campaña de Detección y Vacunación de Hepatitis Virales. Este trabajo tiene como objetivo caracterizar los principales factores de riesgo sexual (FRS) y parenteral (FRP) de los voluntarios asistentes a dicha campaña. Se llevó a cabo un estudio de corte transversal utilizando como instrumento un cuestionario validado. Se encontró que el 37,1%(IC 95%: 32,8-41,6%) de los encuestados refería al menos un FRS, siendo el más prevalente la presencia de relaciones sexuales inseguras con el 68,9% (61,6-75,6%). El 35,7% (31,4-40,1%) presentó al menos un FRP, destacándose aquí la utilización de piercings y tatuajes con el 74,6% (67,4-80,9%) y el 48% (40,3-55,7%) respectivamente. En los individuos mayores de 60 años,los hombres hicieron referencia a mayor exposición a FRS que las mujeres (37,2% vs 16,2%; p= 0,019); mientras que para los menores de 40 años las mujeres presentaron mayor exposición a FRP (64,5% vs 45,0%; p= 0,016). La prevalencia de factores de riesgo aumentó al disminuir la edad de los respondedores. Los jóvenes entre 18 y 30 años mostraron además, asociación entre los FRS y FRP (p= 0,01). Los factores de riesgo estudiados resultan diferenciarse según grupos etarios y género. Es necesario contemplar una educación dirigida a distintos grupos poblacionales, focalizando en las debilidades propias de cada uno

Viral liver disease is a problem and a challenge for physicians and their patients. A campaign for the detection and vaccination againstviral hepatitis was performed in August 2013 in the city of Rosario, Argentina. This work aims to characterize the main sexual (SRF)and parenteral (PRF) risk factors among those volunteers attending the campaign. A cross-sectional study was conducted using avalidated questionnaire. It was found that 37.1% (95% CI: 32.8-41.6%) of the respondents mentioned at least one SRF; the mostprevalent factor was the presence of unsafe sex with 68.9% (61.6-75.6%). On the other hand, 35.7% (31.4-40.1%) referred atleast one PRF, of which the most frequent were the use of piercings and tattoos with 74.6% (67.4-80.9%) and 48% (40,3-55.7%)respectively. Men reported higher exposure to SRF than women (37.2% vs 16.2%, p= 0.019) among individuals older than 60 years;while for those under 40 years, women were more likely to show PRF (64.5% vs 45.0%, p= 0.016). The prevalence of risk factorswas increased while decreasing age of respondents. Young people between 18 and 30 also showed association between SRF and PRF(p = 0,01). Risk factors studied varied according to age groups and genders. It is necessary to provide education targeted to differentpopulation groups, focusing on their particular characteristics and weaknesses of each of them

Factores de riesgo sexual y parenteral en los encuestados durante la campaña contra hepatitis virales 2013, Rosario, Argentina / Sexual and parenteral risk factors in subjects surveyed during a campaign against viral hepatitis (2013), Rosario, Argentina

La enfermedad hepática viral constituye un problema y un desafío para los médicos y sus pacientes. En agosto de 2013 en la ciudad de Rosario se efectuó la Campaña de Detección y Vacunación de Hepatitis Virales. Este trabajo tiene como objetivo caracterizar los principales factores de riesgo sexual (FRS) y parenteral (FRP) de los voluntarios asistentes a dicha campaña. Se llevó a cabo un estudio de corte transversal utilizando como instrumento un cuestionario validado. Se encontró que el 37,1%(IC 95%: 32,8-41,6%) de los encuestados refería al menos un FRS, siendo el más prevalente la presencia de relaciones sexuales inseguras con el 68,9% (61,6-75,6%). El 35,7% (31,4-40,1%) presentó al menos un FRP, destacándose aquí la utilización de piercings y tatuajes con el 74,6% (67,4-80,9%) y el 48% (40,3-55,7%) respectivamente. En los individuos mayores de 60 años,los hombres hicieron referencia a mayor exposición a FRS que las mujeres (37,2% vs 16,2%; p= 0,019); mientras que para los menores de 40 años las mujeres presentaron mayor exposición a FRP (64,5% vs 45,0%; p= 0,016). La prevalencia de factores de riesgo aumentó al disminuir la edad de los respondedores. Los jóvenes entre 18 y 30 años mostraron además, asociación entre los FRS y FRP (p= 0,01). Los factores de riesgo estudiados resultan diferenciarse según grupos etarios y género. Es necesario contemplar una educación dirigida a distintos grupos poblacionales, focalizando en las debilidades propias de cada uno(AU)

Viral liver disease is a problem and a challenge for physicians and their patients. A campaign for the detection and vaccination againstviral hepatitis was performed in August 2013 in the city of Rosario, Argentina. This work aims to characterize the main sexual (SRF)and parenteral (PRF) risk factors among those volunteers attending the campaign. A cross-sectional study was conducted using avalidated questionnaire. It was found that 37.1% (95% CI: 32.8-41.6%) of the respondents mentioned at least one SRF; the mostprevalent factor was the presence of unsafe sex with 68.9% (61.6-75.6%). On the other hand, 35.7% (31.4-40.1%) referred atleast one PRF, of which the most frequent were the use of piercings and tattoos with 74.6% (67.4-80.9%) and 48% (40,3-55.7%)respectively. Men reported higher exposure to SRF than women (37.2% vs 16.2%, p= 0.019) among individuals older than 60 years;while for those under 40 years, women were more likely to show PRF (64.5% vs 45.0%, p= 0.016). The prevalence of risk factorswas increased while decreasing age of respondents. Young people between 18 and 30 also showed association between SRF and PRF(p = 0,01). Risk factors studied varied according to age groups and genders. It is necessary to provide education targeted to differentpopulation groups, focusing on their particular characteristics and weaknesses of each of them(AU)

Driving forces for the adsorption of a His-tag Chagas antigen. A rational approach to design bio-functional surfaces.

In order to rationally design a bio-functional surface based on the adsorption of a His-tag antigen, three requirements have to be considered: the bio-recognition element, the driving forces for the adsorption process and the detection mode of the bio-recognition event. This work is focused on the study of the adsorption mechanism of the His-tag H49 Chagas antigen on Ni(II) modified substrates. In order to construct the bio-functional surface, the gen of the H49 Chagas antigen was modified to incorporate His6 moiety at the N-terminal (His6-H49). Then, its physical adsorption and bio-affinity interaction with the solid substrate was studied by reflectometry. Besides His-Ni(II) bio-affinity interactions, His6-H49 was also physically adsorbed on Ni(II) modified substrates, leading to randomly oriented antigens. These loosely attached bio-molecules were partially removed using conditions of electrostatic repulsion. On the other hand, bio-affinity interactions, resulting in site-oriented molecules on the substrate, were only removable by specific competitors for Ni(II) surface sites. Finally, the surface bio-activity was determined from the peak separations of voltammetry waves due to the change of the electron transfer kinetics of a redox probe through the bio-functional surface (working electrode).

Ni(ii)-modified solid substrates as a platform to adsorb His-tag proteins.

This work investigated a simple and versatile modification to a solid substrate to develop electrochemical bio-recognition platforms based on bio-affinity interactions between histidine (His)-tagged proteins and Ni(ii) surface sites. Carboxylate (COO)-functionalized substrates were prepared in multiple steps, initiated with an amino-terminated self-assembled monolayer (SAM) on polycrystalline gold. Surface enhanced Raman spectroscopy (SERS), quartz crystal microbalance with dissipation monitoring (QCM-D) and contact angle measurements were used to follow the modification process. Upon completion of the modification process, the surface COO-Ni(ii) chelate complex and the coordination mode used to bind the His-tag proteins were characterized by X-ray absorption near-edge spectroscopy (XANES). Finally, the electrochemical stability and response of the modified substrates were evaluated. The versatility of the modification process was verified using silica as the substrate. QCM-D and SERS results indicated that two types of films were formed: a COO-terminated SAM, which resulted from the reduction of previously incorporated surface aldehyde groups, and a physically adsorbed polymeric glutaraldehyde film, which was produced in the alkaline medium. XANES spectral features indicated that COO-Ni(ii) formed a non-distorted octahedral complex on the substrate. The electrochemical stability and response towards a redox mediator of the COO-Ni(ii)-terminated SAM indicated that this platform could be easily coupled to an electrochemical method to detect bio-recognition events.

Infrared study of trifluoroacetic acid unpurified synthetic peptides in aqueous solution: trifluoroacetic acid removal and band assignment.

Synthetic peptide or protein samples are mostly unpurified with trifluoroacetic acid (TFA) used during the synthesis procedure, which strongly interferes with structure determination by infrared (IR) spectroscopy. The aim of this work was to propose a simple strategy to remove TFA contribution from attenuated total reflection (ATR)-IR spectra of the hexahistidine peptide (His6) in aqueous solution to study the conformation of this synthetic peptide without previous purification. Such a strategy is based on the subtraction mode widely employed to remove water contribution, and it is tested with TFA unpurified histidine as a model system. The subtraction is based on eliminating the strong TFA bands at 1147 and 1200cm(-1) by applying a scaling factor (as in buffer correction). The proposed modes represent excellent strategies that do not modify spectral features, and they provide reliable routines to obtain the synthetic peptide spectrum without TFA contribution. The conformational information from the corrected spectra at different pH values is deduced from semiempirical calculated IR spectra of different His6 conformers. The spectral features and the band positions of the corrected spectrum suggest that the peptide molecules mainly adopt an intermolecular ß-sheet structure.

The adsorption-desorption process of bovine serum albumin on carbon nanotubes.

The aim of this work is to study the adsorption-desorption process of bovine serum albumin (BSA) on carbon nanotubes (CNT) by reflectometry. The effect of the surface properties was analyzed by comparing the behavior of BSA on silica. The experiments were performed by reflectometry at different BSA concentrations, at pH 3.0, 4.8, and 7.0 and at two ionic strengths. Protein desorption was induced by either dilution with buffer or the addition of SDS. The initial adsorption rate is controlled by the attachment of BSA molecules to the surface, and strongly diminishes at pH 7. Adsorption isotherms reflect the high affinity of BSA for both sorbent surfaces and reach well-defined plateau values that depend on the pH, being the highest at pH 4.8 on CNT. Experiments performed at different ionic strengths (NaCl added) showed a less pronounced effect. Dilution does not induce desorption on either surface however, the addition of SDS removes protein only from the silica surface.

The binding of Ni(II) ions to hexahistidine as a model system of the interaction between nickel and His-tagged proteins.

The aim of this work is to study the binding of nickel ions to hexahistidine (His(6)) combining potentiometric titrations and spectroscopic (UV-Vis and circular dichroism) determinations in order to establish the species distribution as a function of the pH, their stoichiometry, stability and geometry. For comparative purposes, the same procedure was applied to the Ni-histidine (His) system. His behaves as a tridentate ligand, coordinating the carboxyl group, the imidazole and the amino nitrogen atoms to Ni(II) ions in an octahedral coordination and a bis(histidine) complex is formed at pH higher than 5. For the Ni-His(6) system, the complex formation starts at pH 4 and five different species (Ni(His(6))H, Ni(His(6)), Ni(n)(His(6))(n), Ni(n)(His(6))(n)H(-n/2), Ni(n)(His(6))(n)H(-n)) are formed as a function of the pH. Ni(His(6))H involves the coordination of the imidazole nitrogen and a deprotonated amide nitrogen (N(Im), N(-)) resulting in an octahedral geometry. In Ni(His(6)), an imidazole nitrogen is deprotonated and coordinated (2N(Im), N(-)) to the metal ion with a square planar geometry. The aggregated forms result from the extra Ni-N(Im) coordination, resulting in a 4N square planar geometry that is stabilized by inter/intramolecular hydrogen bonds. This coordination mode is not altered during the deprotonation steps from Ni(n)(His(6))(n).