Singlet molecular oxygen quenching by the antioxidant dimethylmethoxy chromanol in solution and in ex vivo porcine skin.

Singlet-oxygen is a non-radical reactive oxygen species believed to play a major role in many photooxidation processes in connection with diverse photo-biological processes such as skin ageing or photocarcinogenesis. Dimethylmethoxy chromanol (3,4-dihydro-6-hydroxy-2,2-dimethyl-7-methoxy-1(2H)-benzopyran) is a potent antioxidant used in cosmetic and pharmaceutical formulations. We have assessed the singlet oxygen quenching ability of dimethylmethoxy chromanol, by monitoring the near-IR phosphorescence of singlet-oxygen in solution and in ex vivo porcine skin samples. Dimethylmethoxy chromanol quenches singlet oxygen with a rate constant of (1.3 ± 0.1) × 108 M⁻¹ s⁻¹ in solution. Consistent with this, a clear reduction in the singlet oxygen lifetime and emission intensity was observed when ex vivo porcine skin samples were treated with dimethylmethoxy chromanol.

Experimental study of an asymmetric valveless pump to elucidate insights into strategies for pediatric extravascular flow augmentation.

Asymmetric pumping is a sub-category of valveless pumping in which a flexible tube is rhythmically compressed in the transverse symmetry plane. Due to the resulting asymmetry between the suction and discharge pipes, a net pumping head is achieved. Asymmetric pumping is regarded as one of the main mechanisms responsible for the Liebau effect in addition to impedance pumping. However, there remains a paucity of research surrounding the governing parameters of asymmetric pumping. Here, we conducted an experimental study of the performance of an asymmetric pump, with an aim to assess its potential for extravascular flow augmentation. A custom flexible latex tube and experimental platform were developed for this purpose. We tested various tube thicknesses and pinching frequencies. Our results demonstrate that the performance is within the range of physiological requirements for pediatric circulatory devices (~ 1 L/min and < 30 mmHg). We conclude that due to the absence of reverse flow and its mechanical simplicity, pure asymmetric pumping is promising for selected cardiovascular applications with less complexity than other valveless techniques.

Nuclear DNA polymerase beta from Leishmania infantum. Cloning, molecular analysis and developmental regulation.

We have identified a novel polymerase beta (Pol beta)-like enzyme from Leishmania infantum, a parasite protozoon causing disease in humans. This protein, named Li Pol beta, shows a nuclear localization that contrasts with the mitochondrial localization of Pol beta from Crithidia fasciculata, a closely related parasite, the only polymerase beta described so far in Trypanosomatidae. Li Pol beta, that belongs to the DNA polymerase X family, displays an evolutionarily conserved Pol beta-type DNA polymerase core, in which most of the key residues involved in DNA binding, nucleotide binding, dRPase and polymerization catalysis are conserved. In agreement with this, Li Pol beta, overproduced in Escherichia coli, displayed intrinsic DNA polymerase activity. Cell synchronization experiments showed a correlation between both Li Pol beta mRNA and protein levels along the parasite cell cycle. Analysis of these parameters at the different growth phases of the parasite, from the proliferative (non-infective) logarithmic phase to the non-dividing (highly infectious) stationary phase, showed high levels of Li Pol beta at the infective phase of the parasite. The data suggest a role of Li Pol beta in base excision repair in L.infantum, a parasite usually affected by oxygen stress environments into the macrophage host cells.

Oesophageal motility disorders in infected immigrants with Chagas disease in a non-endemic European area.

BACKGROUND: Immigration-related new diseases pose a growing challenge for healthcare services in receptor countries. Following Latin American migration, Chagas disease has inevitably appeared in Europe. AIM: To determine the prevalence and characteristics of oesophageal motility disorders in immigrants infected with Trypanosoma cruzi, using high resolution oesophageal manometry (HREM). METHODS: In all newly-diagnosed cases with chronic Chagas infection referring upper digestive symptoms, a protocolized clinical evaluation and complementary tests including barium oesophagogram and HREM were carried out. As control group, 14 healthy subjects from the same endemic areas were studied with HREM. RESULTS: We included 61 patients (46 female, 15 male; age range 26-63 years). Only seven patients (11%) had a minor alteration on barium oesophagogram. By contrast, 23 (37%) patients showed an alteration in oesophageal manometry, mainly minor motility disorders (34%). Only one healthy control (7%) had a minor motility disorder at HREM (p = 0.029 vs. patients). CONCLUSIONS: Oesophageal motor disorders in infected immigrants with Chagas disease are common, and mainly characterized by a minor motility disorder that is not detected by barium oesophagogram. Hence, as well as barium oesophagogram examination, HREM should be considered, to assess oesophageal damage in this specific group of patients.

DNA polymerase lambda (Pol lambda), a novel eukaryotic DNA polymerase with a potential role in meiosis.

A new gene (POLL) encoding a novel DNA polymerase (Pol lambda) has been identified at mouse chromosome 19. Murine Pol lambda, consisting of 573 amino acid residues, has a 32% identity to Pol beta, involved in nuclear DNA repair in eukaryotic cells. It is interesting that Pol lambda contains all the critical residues involved in DNA binding, nucleotide binding and selection, and catalysis of DNA polymerization, that are conserved in Pol beta and other DNA polymerases belonging to family X. Murine Pol lambda, overproduced in Escherichia coli, displayed intrinsic DNA polymerase activity when assessed by in situ gel analysis. Pol lambda also conserves the critical residues of Pol beta required for its intrinsic deoxyribose phosphate lyase (dRPase) activity. The first 230 amino acid residues of Pol lambda, that have no counterpart in Pol beta, contain a BRCT domain, present in a variety of cell-cycle check-point control proteins responsive to DNA damage and proteins involved in DNA repair. Northern blotting, in situ hybridization analysis and immunostaining showed high levels of Pol lambda specifically expressed in testis, being developmentally regulated and mainly associated to pachytene spermatocytes. These first evidences, although indirect, suggest a potential role of Pol lambda in DNA repair synthesis associated with meiosis.

Hot water dipping of olives (Olea europaea) for virgin oil debittering.

Olives (Olea europaea L.) of the Manzanilla, Picual, and Verdial varieties harvested at the green mature stage of ripening were dipped in hot water at a range of temperatures between 60 and 72 degrees C for 3 min. Immediately after treatment, oils were physically extracted from the olives. Olive heating promotes a reduction of oil bitterness in direct relationship to the temperature used. Fruit heating at > or =60 degrees C for 3 min did not cause significant changes in acidity, UV absorption, peroxide index, and panel test score of the oils obtained but decreased its oxidative stability. Oils extracted from heated fruit showed higher concentrations of chlorophylls and carotenes and lower total phenol content.

A specific, low Km ADP-ribose pyrophosphatase from rat liver.

Two rat liver ADP-ribose pyrophosphatases (ADPRibases) were partially purified. ADPRibase-I hydrolyzed ADP-ribose (Km = 0.5 microM) giving AMP as a product, required Mg2+ or, less efficiently, Mn2+ (Ca2+ was not active), its activity changed little between pH 7 and 9, and was specific for ADP-ribose as it did not hydrolyze ADP-glucose, NAD+, NADH or diadenosine 5',5"'-P1,Pn-n-phosphates (Ap2A, Ap3A). ADPRibase-II showed similar properties, except that the Km for ADP-ribose was 50 microM and may be non-specific, as the same preparation hydrolyzed ADP-glucose, NADH and Ap2A. ADPRibase-I fulfills the requirements of a specific turnover pathway consistent with a cellular role for free ADP-ribose.

Temperature and oxygen regulation of oleate desaturation in developing sunflower (Helianthus annuus) seeds.

The effect of low (10 degrees C) and high (30 degrees C) temperature on in vivo oleate desaturation has been studied in developing sunflower (Helianthus annuus L.) seeds under conditions of different oxygen availability (capitulum, detached achenes or peeled seeds). In seeds remaining in the capitulum, only a part of the oleate newly synthesized at high temperature was desaturated to linoleate, whereas more oleate than that synthesized de novo was desaturated at low temperature. Achenes were only able to significantly desaturate oleate at low temperatures. In contrast, oleate desaturation was detected in peeled seeds incubated at low and high temperatures, showing the highest rate at 20 degrees C. Hull removing dramatically increased the activity of the microsomal oleate desaturase (FAD2, EC 1.3.1.35) at all studied temperatures, although a long-term inactivation of the enzyme was observed at high temperatures. Low oxygen concentration (1-2%) obtained by respiration of peeled seeds incubated in sealed vials, brought about the inactivation of the enzyme. All these data suggest that temperature regulates oleate desaturation controlling the amount of oleate and the FAD2 activity. In addition, this enzyme seems to be also regulated by the availability of oxygen, which is affected inside the achene by its diffusion through the hull, and the competition with respiration, both factors being temperature-dependent.

Low protein concentration in cirrhotic ascites is related to low ascitic concentrations of immunoglobulins G and A.

OBJECTIVE: To analyse the differences in ascitic and serum levels of immunoglobulins and albumin between two groups of cirrhotic patients (with ascitic total protein levels higher and lower than 10 g/l). DESIGN: A prospective study. PATIENTS AND METHODS: We studied 39 cirrhotic patients with sterile ascites. The patients were classified into two groups: group A (18 patients) comprised those with an ascitic total protein level less than 10 g/l and group B (21 patients) those with an ascitic total protein level higher than 10 g/l. Ascitic and serum levels of albumin and immunoglobins G, A and M were analysed. RESULTS: Ascitic immunoglobulin G and A levels in group B were higher than ascitic immunoglobulin G and A levels in group A. Ascitic levels of these immunoglobulins correlated linearly with ascitic total protein levels. The serum levels of immunoglobulins G and A in groups A and B were not significantly different. Ascitic and serum immunoglobulin M concentrations in the two groups were similar. Transfer of immunoglobulins G and A and albumin from plasma to ascites seemed to be similar in group B. Transfer of immunoglobulins G and A seemed to be impaired in group A. Differences in ascitic immunoglobulin levels between groups A and B were also observed in the presence of diuretic treatment. Differences in ascitic immunoglobulin levels were related to the Child-Pugh score. CONCLUSION: Patients with a low ascitic total protein level show low ascitic immunoglobulin G and A concentrations. The low ascitic immunoglobulin G and A levels could be related to an impairment in the transfer of these immunoglobulins from plasma in those patients who have poor liver function. Ascitic immunoglobulin M is not related to ascitic total protein, and its origin is not clear. The putative transfer of immunoglobulin M to the peritoneal cavity is not related to the mechanism of transfer of albumin or of immunoglobulins G and A from serum. The physiological significance of ascitic immunoglobulin M is unclear.

[Poisoning by delayed-release verapamil in an uremic patient]. / Intoxicación por verapamilo de liberación lenta en un enfermo urémico.

The appearance of toxic effects upon consumption of delayed release verapamil at therapeutic doses (120 mg/12 h) in a 64 year old patient with renal failure is described. The patient presented hypotension, bradycardia due to auriculoventricular block, hepatotoxicity, slight hyperglycemia, hyperpotassemia and metabolic acidosis with increased anionic gap. The picture remitted spontaneously with support treatment following discontinuation of the medication. The pathogenesis of the syndrome and the possibility that the hepatotoxicity was the triggering factor are discussed. Extreme precaution is recommended when this type of drugs is used in severe uremic or diabetic patients.

[Acute renal failure associated with 5-aminosalicylic acid in inflammatory bowel disease]. / Insuficiencia renal aguda asociada a ácido 5-aminosalicílico en la enfermedad inflamatoria intestinal.

A case of acute renal failure with characteristics of interstitial nephritis associated to treatment with mesalazine (5-ASA bound to resin) in a 26-year old patient with a 7-year history of Crohn's disease is presented. The patient had been previously treated with 5-ASA with no alterations in renal function being observed. Renal failure became manifest several days after initiation of maintenance therapy with 5-ASA during the latest outbreak of intestinal inflammatory disease and disappeared upon suppression of the drug.

[Lung carcinoma and chronic lymphocytic leukemia: report of a synchronous diagnosis]. / Carcinoma de pulmón y leucemia linfoide crónica: a propósito de un diagnóstico sincrónico.

In the follow-up of patients with chronic lymphocytic leukemia seems to exist an increased risk to develop other neoplasms, as lung carcinoma. However it is exceptional that the lung carcinoma precede the chronic lymphocytic leukemia, or their simultaneous diagnosis, because there are only isolated references in the literature. We present a rare case of a man 75 years-old, very smoker, diagnosed of synchronous cancer of squamous cell carcinoma of the lung, and chronic lymphocytic leukemia upon-evaluating respiratory symptoms of two months of evolution. Also, they are discussed the possible pathogenesis of this association together with a review of the literature.

[Ultrasound-guided infraclavicular axillary vein cannulation]. / Canalización de la vena axilar infraclavicular guiada por ecografía.

BACKGROUND AND OBJECTIVE: Percutaneous central venous cannulation is a challenging procedure. Traditionally, an external landmark technique has been used to identify puncture site. We wanted to evaluate an ultrasound-guided technique for the axillary vein cannulation, looking specifically at the ease of use, success rate and decreased complications. METHODS: Sixty consecutive surgical patients scheduled for central venous catheter placement were registered. An ultrasound scanner made for guiding an in plane puncture of axillary vein was used. After locating the vessels, an echo-guided sterile procedure was performed to cannulate the vein. RESULTS: Cannulation was successful in all patients, and there were no complications during insertion of the catheters. Both axillary veins were cannulated, and the vein was punctured successfully at first attempt in 95% of the patients. The median time from the start of the first puncture (of the skin) until the aspiration of blood was 15 (7- 135) seconds. CONCLUSION: This ultrasound-guided technique for inserting central venous catheters in axillary vein was easy to apply. This procedure could increase precision and safety in patients undergoing axillary vein cannulation.

[Clarity of recommendations for patients in the hospital discharge report]. / Claridad de las recomendaciones al paciente en el informe de alta hospitalaria.

BACKGROUND: Recommendations for patients (RP) are one of the key parts of the hospital discharge report (HDR). The objective was to study the frequency of RP in the HDR of different specialties and the proportion of them considered to be easy to understand. MATERIAL AND METHOD: Observational and cross-sectional study. SETTING: General acute care hospital. INTERVENTIONS: Review of a sample of HDR, analysis of the frequency and types of PR based on their content and clarity. RESULTS: A total of 840 HDR and 2,097 PR were analysed with an average of 2.5 RP per report. The most common RP referred to the patient follow-up (46% of total), followed by specific recommendations for the days immediately following discharge (37%), with only 16% related to lifestyle. Reports by surgical specialties contained 3.2 RP compared to 2.3 in medical specialties. The large majority (90.3%) of the RP were considered clear to understand for a standard patient. CONCLUSIONS: The HDR analysed contained few RP, in particular those related to lifestyles. A substantial proportion of the RP were not expressed with enough clarity.

[Evolution and characteristics of primary care patients with painful shoulder]. / Evolución y características de los pacientes con hombro doloroso en atención primaria.

OBJECTIVES: To describe the population attending teaching health centres in Area V, Asturias, to consult for painful shoulder. To describe the examination, diagnosis, treatment and clinical response. DESIGN: Longitudinal, descriptive study. SETTING: Teaching health centres in Area V, Asturias. PARTICIPANTS: Patients consulting because of pain in their shoulders in October and November 2002. MAIN MEASUREMENTS: Two measurements, the first of which in December 2002 appraised age, sex, job, time off work, arc of pain, flection, internal-external rotation, and diagnostic impression. The second, in May 2003, assessed evolution, x-rays, echography, medication, infiltration, physiotherapy, exercises at home, referral to specialist, and final diagnosis. Bivariant and kappa index descriptive analyses were run. RESULTS: 110 cases, 58.2% women and 41.8% men, with an average age of 57 (95% CI, 54.17-59.79), were included. 52.7% were retired; no particular job predominated; 7.3% were off work; 30% had had no examination of arc of movement; 70% evolved satisfactorily. The most common diagnosis was cuff tendinitis, with initial and final diagnosis coinciding well. 77.4% of patients took NSAIDs; 16% were infiltrated; 32.1% did physiotherapy; and 36.8%, exercises at home. 65.1% had no x-ray and only 6.6% had echographies, all of which found something. There was no statistically significant relationship between medication or infiltration and favourable evolution; and there was, between physiotherapy or exercises and favourable evolution. CONCLUSIONS: Most patients were middle-aged, women, pensioners, and had little time off work. Two-thirds evolved well. Examinations were incomplete and few complementary tests were run.

Alcohol esterification reactions and mechanisms of snake venom 5'-nucleotide phosphodiesterase.

In a previous study we have shown that snake venom 5'-nucleotide phosphodiesterase (SVP) catalyzes methanol-esterification reactions [García-Díaz, M., Avalos, M. & Cameselle, J. C. (1991) Eur. J. Biochem. 196, 451-457]. Now we have demonstrated that SVP catalyzes AMP transfer from ATP to propanol, ethanol, methanol, ethylene glycol, glycerol, 2-chloroethanol or 2,2-dichloroethanol. The AMP-O-alkyl ester products were identified by HPLC, enzyme analysis, ultraviolet and NMR spectroscopy. Those results show the potential of SVP as a tool to prepare 5'-nucleotide esters and agree with the formation of a covalent 5'-nucleotidyl-SVP intermediate susceptible to nucleophilic attack by short-chain (poly)alcohols as acceptors alternative to water. To test the kinetic influence of the solvent nucleophile in SVP mechanisms, initial rates of ATP solvolysis were assayed in different water/alcohol mixtures. Relatively high alcohol concentrations inactivated SVP but lower concentrations gave proportional rates of alcoholysis. An efficiency parameter (EA), defined as the ratio of the mole fraction of AMP-O-alkyl ester as a product to that of alcohol as an acceptor in water/alcohol mixtures, made possible the comparison of alcohols and water as AMP acceptors at low concentrations, as it could be reasoned that EA = 1 for water. Rates of hydrolysis (VH) of substrates yielding AMP and different leaving groups were also assayed. The higher EA and VH values corresponded, respectively, to those acceptors and leaving-group conjugate acids with lower pKa and higher polar-substituent constants (sigma*). The results support the occurrence of general acid-base catalysis in the active center of SVP and the identification of rate-limiting steps. A model is proposed for the mechanisms of SVP-catalyzed hydrolysis and alcoholysis which accounts for the influence of the acid-base properties of alcohols on the kinetic profile of SVP reaction sequences.

Methanol esterification reactions catalyzed by snake venom and bovine intestinal 5'-nucleotide phosphodiesterases. Formation of nucleoside 5'-monophosphate methyl esters from guanosine 5'-triphosphate and other nucleoside 5'-polyphosphates.

It is not known whether the enzymes 5'-nucleotide phosphodiesterase/nucleotide pyrophosphatase (EC 3.1.4.1/EC 3.6.1.9) catalyze the transfer of nucleotides to acceptors other than water. We have investigated the action of snake venom and bovine intestinal mucosa phosphodiesterases on nucleoside 5'-polyphosphates in the presence of methanol. In those conditions, GTP was converted by snake venom phosphodiesterase to a mixture of GMP and another compound with a different retention time in reverse-phase high-performance liquid chromatography. That compound, by ultraviolet, 1H- and 13C-nuclear magnetic resonance spectroscopic analysis, and by enzyme analysis, was characterized as the methyl ester of GMP (GMP-OMe). The molar fraction [GMP-OMe]/[GMP + GMP-OMe] formed was higher than the molar fraction of methanol as a solvent in reaction mixtures. Similar reactions took place at comparable rates with snake venom and bovine intestinal mucosa phosphodiesterases using several nucleoside 5'-polyphosphates as substrates. The ability of 5'-nucleotide phosphodiesterases to catalyze transfer reactions to a non-water acceptor is relevant to the mechanism of the enzymes, to their use as analytical tools, and to their possible use/role in the preparative/in vivo synthesis of nucleotide esters.