Intrinsic and selective activity of functionalized carbon nanotube/nanocellulose platforms against colon cancer cells.

Given their large surface area and versatile chemical reactivity, single-walled carbon nanotubes (SWCNTs) are regarded as the basis of new pharmacological complexes. In this study, SWCNTs are chemically functionalized with fluorescein, folic acid, and capecitabine, a drug that is commonly used against colorectal cancer. These functionalized SWCNTs are dispersed in water by taking advantage of their synergistic interaction with type-II nanocrystalline cellulose (II-NCC), and the resulting colloidal system is tested in vitro on both normal (differentiated) and cancerous (proliferative) human colon cells (Caco-2). The functionalized SWCNT/II-NCC hybrids show a higher activity than the reference (capecitabine) against the Caco-2 cancer cell line. However, this effect appears to be intrinsically associated with the SWCNT/II-NCC complex, particularly boosted by fluorescein, as the presence of capecitabine is not required. In addition, confocal microscopy fluorescence imaging using cell cultures highlights the enormous potential of this nanohybrid platform for colon cancer theranostics.

Highly sensitive electrochemiluminescence detection of a prostate cancer biomarker.

Prostate-specific membrane antigen (PSMA), a glycoprotein expressed in the prostatic epithelium endowed with enzymatic activity, is a very promising diagnostic marker for the early detection of prostate cancer. In this study, we report a novel electrochemiluminescence ELISA-like immunosensor based on carbon nanotubes and a highly specific sandwich immunoassay for the PSMA detection. To fabricate the device, an optically transparent electrode was modified with doubly functionalized multi-walled carbon nanotubes carrying amine groups and a monoclonal anti-PSMA antibody. Subsequently, to complete the sandwich immunosensing device, a second specific monoclonal anti-PSMA antibody was labelled with a electrochemiluminescent probe. Under optimized experimental conditions, the proposed sensing device exhibits a performance exceeding that of the state of-the-art in terms of the limit of detection (LOD) and limit of quantification (LOQ) as good as 0.88 ng mL-1 and 2.60 ng mL-1, respectively, in real complex samples such as cell lysates. In addition, the unique role of carbon nanotubes is also discussed by comparison with an analogue sensor assembled without the nanocarbon-based material.

RNASET2 is required for ROS propagation during oxidative stress-mediated cell death.

RNASET2 is a ubiquitously expressed acidic ribonuclease that has been implicated in diverse pathophysiological processes including tumorigeneis, vitiligo, asthenozoospermia, and neurodegeneration. Prior studies indicate that RNASET2 is induced in response to oxidative stress and that overexpression of RNASET2 sensitizes cells to reactive oxygen species (ROS)-induced cell death through a mechanism that is independent of catalytic activity. Herein, we report a loss-of-function genetic screen that identified RNASET2 as an essential gene for lipotoxic cell death. Haploinsufficiency of RNASET2 confers increased antioxidant capacity and generalized resistance to oxidative stress-mediated cell death in cultured cells. This function is critically dependent on catalytic activity. Furthermore, knockdown of RNASET2 in the Drosophila fat body confers increased survival in the setting of oxidative stress inducers. Together, these findings demonstrate that RNASET2 regulates antioxidant tone and is required for physiological ROS responses.

Influence of storage time on pleural fluid adenosine deaminase activity.

BACKGROUND: Storing pleural fluid samples for research purposes is a common practice, but whether adenosine deaminase (ADA), an enzyme used for the diagnosis of tuberculous pleuritis, is stable over long periods of time is unknown. METHODS: We evaluated the stability of pleural ADA concentrations in 223 samples frozen at -800C as compared to values obtained immediately following the initial thoracentesis. Sample storage time ranged from several months to slightly more than 10 years. RESULTS: ADA activity was stable for up to 2.6 years. Afterwards, it decreased 6 to 8 U/L, enough to drop 2 (3.3%) tuberculous patients below the diagnostic ADA cutoff. CONCLUSIONS: As far as ADA enzymatic activity is concerned, pleural fluid samples are viable for extended periods of time. However, some caution in interpreting results from specimens stored for > 2.6 years is prudent.

[Sedation in surgical procedures using regional anesthesia in adult patients: results of a survey of Spanish anesthesiologists]. / Sedación para procedimientos quirúrgicos realizados con anestesia regional en pacientes adultos. Resultados de una encuesta entre anestesiólogos españoles.

OBJECTIVE: To analyze the frequency and methods of sedation used in the context of regional anesthesia in adults by means of a national survey. MATERIAL AND METHODS: We carried out a survey of participants at the courses of an anesthesiology training organization (Fundación Europea de Enseñanza en Anestesiología), held in Spain in 2006. The survey questionnaires asked about indications for sedation used during surgery under regional anesthesia as well as the form of administration, follow-up, and complications. RESULTS: A total of 375 questionnaires were sent out and 185 responses were received (49.3%). Sedation is always used to accompany regional anesthesia by 69.2% of the respondents; 13.5% of them discuss the technique to be used with the patient and come to an agreement. The same type of sedation, regardless of the regional block performed, is used by 49.2% of respondents, and 64.3% use a scale to evaluate the level of sedation. The most favored sedation technique is continuous infusion, followed by target controlled infusion and boluses on demand. The most commonly used technique is sedation with bolus injections. Sixty percent use a single agent and 38.9% use combinations. The most commonly reported adverse effects are variability of patient response (53.5%) and respiratory complications (27%). In cases of ineffective regional blockade, 49.2% of those surveyed switch to general anesthesia. CONCLUSIONS: Sedation is very often used to complement regional anesthesia in adult patients. Even though continuous infusion is considered to be the most appropriate form of administration, the most commonly used form is injection of boluses. Sedation with a single drug is used more frequently than drug combinations. Variability of individual response is the complication most commonly reported by the respondents.

[Hafnia alvei in a rare case of severe pneumonia in a postanesthesia recovery unit]. / Hafnia alvei: una causa infrecuente de neumonía grave en la unidad de reanimación.

An 85-year-old man with a history of moderate chronic obstructive pulmonary disease in treatment with anticholinergic drugs was admitted to the recovery unit for postoperative monitoring after right inguinal herniorrhaphy surgery and removal of a strangulated intestinal section. On the third day after surgery the patient developed radiographic signs consistent with pneumonia and required mechanical ventilation. Two blood cultures and a respiratory secretion sample grew a microorganism identified as Hafnia alvei. H. alvei is a gram-negative bacillus that colonizes the digestive tract of humans and animals and in immunodepressed patients it can colonize the mouth and pharynx. Isolation of H. alvei is described in the literature on pediatric patients and those with a history of immune deficiency or chronic disease. Infection has a severe impact on general health. We report a rare and interesting case of pneumonia and bacteremia from H. alvei infection acquired by an immunocompetent patient soon after arrival in the postoperative recovery unit. The patient died of the infection.

[Hospital registry of pancreatic tumors. Experience of the Hospital Clínic in Barcelona (Spain)]. / Registro hospitalario de tumoraciones pancreáticas. Experiencia del Hospital Clínic de Barcelona.

OBJECTIVE: To describe the characteristics of patients included in the pancreatic tumor registry of the Hospital Clínic of Barcelona. PATIENTS AND METHOD: All patients with pancreatic tumors attended between July 1990 and March 2003 were registered. Data collection included: age, gender, date of diagnosis, diagnosis, histology, size, location and tumor stage, and treatment. The correlation between tumor stage and age, date of diagnosis, and tumor location was also evaluated. RESULTS: Six hundred thirty patients with pancreatic tumors were included, representing an incidence of 60 patients/year. The mean age was 66 years and the male-to-female ratio was 1,18:1. The most frequent lesion was malignant tumor of the pancreas (92%), and the most frequent histological type was pancreatic ductal adenocarcinoma (73%). The most frequent location was the head of the pancreas (64%). In 28% of the patients, pancreatic cancer was diagnosed in stage I and II. Resection was performed in 31% of patients, whereas 48% of the patients received no treatment. The ratio between local (stage I)/disseminated (stage IV) disease was 0,34. The ratio between stage I/IV increased with age, diagnosis prior to 1994, and tumor location in the head of the pancreas. CONCLUSION: Hospital tumor registries can be used to define the profile of the attended population, which can help to delineate the best diagnostic-therapeutic strategy and can be useful in clinical research.

Adenosine diphosphate sugar pyrophosphatase prevents glycogen biosynthesis in Escherichia coli.

An adenosine diphosphate sugar pyrophosphatase (ASPPase, EC ) has been characterized by using Escherichia coli. This enzyme, whose activities in the cell are inversely correlated with the intracellular glycogen content and the glucose concentration in the culture medium, hydrolyzes ADP-glucose, the precursor molecule of glycogen biosynthesis. ASPPase was purified to apparent homogeneity (over 3,000-fold), and sequence analyses revealed that it is a member of the ubiquitously distributed group of nucleotide pyrophosphatases designated as "nudix" hydrolases. Insertional mutagenesis experiments leading to the inactivation of the ASPPase encoding gene, aspP, produced cells with marginally low enzymatic activities and higher glycogen content than wild-type bacteria. aspP was cloned into an expression vector and introduced into E. coli. Transformed cells were shown to contain a dramatically reduced amount of glycogen, as compared with the untransformed bacteria. No pleiotropic changes in the bacterial growth occurred in both the aspP-overexpressing and aspP-deficient strains. The overall results pinpoint the reaction catalyzed by ASPPase as a potential step of regulating glycogen biosynthesis in E. coli.

Two isoforms of a nucleotide-sugar pyrophosphatase/phosphodiesterase from barley leaves (Hordeum vulgare L.) are distinct oligomers of HvGLP1, a germin-like protein.

Two isoforms of ADPglucose pyrophosphatase/phosphodiesterase (AGPPase) have been characterized using barley leaves (Hordeum vulgare L.). Whilst one of the isoforms, designated as soluble AGPPase1 (SAGPPase1), is soluble in low ionic strength buffers, the other, SAGPPase2, is extractable using cell wall hydrolytic enzymes or high salt concentration solutions, thus indicating that it is adventitiously bound to the cell wall. Both AGPPase isoforms are highly resistant to SDS, this characteristic being utilized to purify them to homogeneity after zymographic detection of AGPPase activity in SDS-containing gels. N-terminal and internal amino acid sequencing analyses revealed that both SAGPPase1 and SAGPPase2 are distinct oligomers of the previously designated HvGLP1, which is a member of the ubiquitously distributed group of proteins of unknown function designated as germin-like proteins (GLPs).

[Anesthesia in a case of Holt-Oram syndrome]. / Anestesia en un caso de síndrome de Holt-Oram.

A 19-year-old man with Holt-Oram syndrome (HOS) underwent emergency surgical treatment of an occipital abscess. He presented total aplasia of the radius and first and second finger of the left hand, asymmetric thorax and complex cyanotic cardiopathy with double output of the right ventricle that had been treated on several occasions, malpositioning of the large vessels and interventricular conduction. He had been treated with digoxin for episodes of supraventricular tachycardia. After premedication with 0.4 mg of atropine, balanced general anesthesia was induced with etomidate and remifentanil and maintained with O2/air/desflurane and infused remifentanil. The patient remained hemodynamically stable during surgery and tubes were removed in the operating room with no complications. HOS, a hereditary disease characterized by congenital malformations of the upper extremities and the heart, is often associated with rhythm disorders. Problems that may develop in such patients during anesthesia include difficulty catheterizing vessels, difficult orotracheal intubation and ventilation, hemodynamic instability, and the presentation of arrhythmias and cardiac arrest.

Distinct isoforms of ADPglucose pyrophosphatase and ADPglucose pyrophosphorylase occur in the suspension-cultured cells of sycamore (Acer pseudoplatanus L.).

The intracellular localizations of ADPglucose pyrophosphatase (AGPPase) and ADPglucose pyrophosphorylase (AGPase) have been studied using protoplasts prepared from suspension-cultured cells of sycamore (Acer pseudoplatanus L.). Subcellular fractionation studies revealed that all the AGPPase present in the protoplasts is associated with amyloplasts, whereas more than 60% of AGPase is in the extraplastidial compartment. Immunoblots of amyloplast- and extraplastid-enriched extracts further confirmed that AGPase is located mainly outside the amyloplast. Experiments carried out to identify possible different isoforms of AGPPase in the amyloplast revealed the presence of soluble and starch granule-bound isoforms. We thus propose that ADPglucose levels linked to starch biosynthesis in sycamore cells are controlled by enzymatic reactions catalyzing the synthesis and breakdown of ADPglucose, which take place both inside and outside the amyloplast.

Adenosine diphosphate glucose pyrophosphatase: A plastidial phosphodiesterase that prevents starch biosynthesis.

A distinct phosphodiesterasic activity (EC 3.1.4) was found in both mono- and dicotyledonous plants that catalyzes the hydrolytic breakdown of ADPglucose (ADPG) to produce equimolar amounts of glucose-1-phosphate and AMP. The enzyme responsible for this activity, referred to as ADPG pyrophosphatase (AGPPase), was purified over 1,100-fold from barley leaves and subjected to biochemical characterization. The calculated K(eq)' (modified equilibrium constant) value for the ADPG hydrolytic reaction at pH 7.0 and 25 degrees C is 110, and its standard-state free-energy change value (DeltaG') is -2.9 kcal/mol (1 kcal = 4.18 kJ). Kinetic analyses showed that, although AGPPase can hydrolyze several low-molecular weight phosphodiester bond-containing compounds, ADPG proved to be the best substrate (K(m) = 0.5 mM). P(i) and phosphorylated compounds such as 3-phosphoglycerate, PP(i), ATP, ADP, NADP(+), and AMP are inhibitors of AGPPase. Subcellular localization studies revealed that AGPPase is localized exclusively in the plastidial compartment of cultured cells of sycamore (Acer pseudoplatanus L.), whereas it occurs both inside and outside the plastid in barley endosperm. In this paper, evidence is presented that shows that AGPPase, whose activity declines concomitantly with the accumulation of starch during development of sink organs, competes with starch synthase (ADPG:1,4-alpha-d-glucan 4-alpha-d-glucosyltransferase; EC) for ADPG, thus markedly blocking the starch biosynthesis.

Atypical retroperitoneal fibrosis: MRI findings.

A case of retroperitoneal fibrosis with an unusual perirenal involvement diagnosed at MR imaging is reported. Other conditions, such as metastatic disease or lymphoma, may be considered especially when the initial presentation is not typical. Imaging modalities in this condition are discussed.

Warm ischemic time tolerance after ventilated non-heart-beating lung donation in piglets.

OBJECTIVE: The availability of lungs for transplantation could be ameliorated with the use of organs retrieved from ventilated non-heart-beating donors (VNHBD). The aim of this work is to determine the limit to tolerable in situ warm ischemia time (WIT) for lung grafts after circulation is stopped. METHODS: Twenty piglets underwent left lung allotransplantation. Animals were randomly allocated based on the donor's status before lung harvesting into the following study groups: Sham (n = 5), Heart-beating donors-non-warm ischemia; I-30 (n = 5), I-60 (n = 5) and I-90 (n = 5), VNHBD-WIT of 30, 60 and 90 min, respectively. Right pulmonary artery and bronchus were permanently occluded one hour after transplantation. Assessment of pulmonary function was monitored hourly by hemodynamic, oxygenation and pulmonary mechanic measurements during a period of 6 h after reperfusion. Lung grafts were weighed pre- and post-transplantation. RESULTS: Cold ischemic time was similar for all groups, and averaged 80.1+/-2.7 min. Final mean lung weight was significantly greater in VNHBD (92.5+/-3.1 g vs. Sham values 75.6+/-2.4 g, P < 0.01). After right lung exclusion, hemodynamic changes consisted of a sustained increase in pulmonary vascular resistance and a reduction in cardiac output. Lung mechanics also modified, with a rise in airway resistance and a fall in compliance. CONCLUSIONS: Post-transplantation lung graft function from VNHBD with up to 90 min of WIT, is equivalent to those achieved by grafts harvested after heart-beating donation. This method may be a promising strategy of increasing the pulmonary donor pool.

[Predictive factors of inotropic support in myocardial revascularization surgery]. / Factores predictivos de soporte inotrópico en cirugía de revascularización miocárdica.

OBJECTIVES: The use of perioperative inotropics in myocardial revascularization surgery can be considered a marker of ventricular dysfunction, the etiology of which involves a variety of pre- and intraoperative factors. Knowledge of the risk factors and their relative importance can allow them to be modified for improved outcome. This study aims to determine the incidence of and factors that predict the need for inotropic support in order to finalize extracorporeal circulation and in the first 6 hours after myocardial revascularization. PATIENTS AND METHODS: Two hundred forty-two patients who underwent myocardial revascularization were studied retrospectively. The parameters collected were age, sex, NYHA classification, left ventricular telediastolic pressure at baseline and after contrast, ejection fraction, collateral circulation, number of distal anastomoses, time of clamping, time of extracorporeal circulation, need for inotropic support to end extracorporeal circulation and during the first 6 hours after surgery. RESULTS: Inotropics were used in 27.6% of the sample. The need for inotropic support was related to female sex (odds ratio [OR] 3.85 with 95% confidence interval [CI], 1.56-9.49); NYHA class III (OR 2.13 with 95% CI, 1.05-4.32) or IV (OR 10.16 with 95% CI, 3.22-32.13); low injection fraction (OR 2.41 with 95% CI, 1.22-4.76); and prolonged extracorporeal circulation (OR 2.97 with 95% CI, 1.54-5.76). CONCLUSIONS: The independent variables associated with the need for inotropic support during the perioperative period in myocardial revascularization are NYHA functional class III and IV, female sex, low injection fraction and prolonged extracorporeal circulation. New techniques for myocardial protection during extracorporeal circulation, plus adequate peroperative stabilization of patients and shorter time of extracorporeal circulation will probably diminish short term morbidity in revascularization surgery.

[Latex allergy in anesthesiology]. / Alergia al látex en anestesiología.

Allergy to latex, described 15 years ago, is increasing. It affects mainly certain risk groups, such as health-care workers and patients with spina bifida or genitourinary malformations. Symptoms vary in intensity from mild to life-threatening and can present during any medical procedure involving skin or mucosal contact, or inhalation, of the allergen in a previously sensitized patient. The most serious cases reported have generally involved patients undergoing surgery. Prevention is based mainly on tentative diagnosis made when the patient's history is taken, followed by laboratory tests and consultation with an allergist. Because prophylactic drug protocols have proven ineffective, the patient must be offered a latex-free environment in keeping with standard recommendations.

[Electromyographic response to precurarization with vecuronium bromide]. / Respuesta electromiográfica de la precurarización con bromuro de vecuronio.

OBJECTIVE: To analyze electromyographic response and clinical effects after precurarization with vecuronium bromide (0.01 mg/Kg), also noting intubation conditions and the presence or not of fasciculations after administration of succinylcholine (1.5 mg/Kg). PATIENTS AND METHODS: A single precurarization dose of vecuronium was administered to 20 patients 5 minutes before anesthetic induction for general surgery. During this period we monitored neuromuscular transmission of the cubital nerve in the wrist by electromyography with a series of 4 stimuli, expressing each as the percentage of the first response and of the ratio T4/T1. We also recorded clinical repercussions. General anesthesia was then induced; after administration of succinylcholine, the presence or not of fasciculations was noted and intubation conditions were evaluated. RESULTS: The electromyographic response after precurarization was highly variable, as 4 different responses were recorded. We found potentiation phenomena in 20% of our patients, diminished response in 60%, fatigue phenomena in 15% and no change in 5%. Clinical signs noted were blurred vision and heavy eyelids. Fasciculations disappeared in 95% of the patients and intubation conditions were excellent. CONCLUSIONS: Vecuronium at a precurarization dose produces highly varied but well-tolerated electromyographic responses. The drug is effective in eliminating fasciculations produced by succinylcholine and does not affect intubation conditions.