RESUMO
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⻹ s⻹ 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.
Assuntos
Antioxidantes/química , Cromanos/química , Oxigênio Singlete/química , Pele/química , Animais , Soluções , SuínosRESUMO
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.
Assuntos
Sistema Cardiovascular , Coração , Humanos , Criança , Fluxo Pulsátil/fisiologia , Coração/fisiologiaRESUMO
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.
Assuntos
DNA Polimerase beta/genética , Leishmania infantum/genética , Sequência de Aminoácidos , Animais , Northern Blotting , Ciclo Celular/genética , Núcleo Celular/enzimologia , Clonagem Molecular , DNA Polimerase beta/química , DNA Polimerase beta/metabolismo , DNA Complementar/química , DNA Complementar/genética , Imunofluorescência , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Leishmania infantum/enzimologia , Leishmania infantum/crescimento & desenvolvimento , Dados de Sequência Molecular , Conformação Proteica , Estabilidade de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de AminoácidosRESUMO
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.
RESUMO
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.
Assuntos
DNA Polimerase Dirigida por DNA/metabolismo , Células Eucarióticas/enzimologia , Meiose , Sequência de Aminoácidos , Animais , Clonagem Molecular , Sequência Conservada , DNA Polimerase beta/química , DNA Polimerase beta/metabolismo , Reparo do DNA , DNA Polimerase Dirigida por DNA/química , DNA Polimerase Dirigida por DNA/genética , Células Eucarióticas/citologia , Éxons/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Humanos , Íntrons/genética , Masculino , Meiose/genética , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína , RNA Mensageiro/análise , RNA Mensageiro/genética , Saccharomyces cerevisiae/enzimologia , Alinhamento de Sequência , Espermátides/enzimologia , Espermatócitos/enzimologia , Testículo/citologia , Testículo/enzimologia , Testículo/metabolismoRESUMO
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.
Assuntos
Manipulação de Alimentos/métodos , Frutas/química , Temperatura Alta , Olea , Óleos de Plantas , Paladar , Azeite de Oliva , Fenóis/análise , ÁguaRESUMO
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.
Assuntos
Fígado/enzimologia , Pirofosfatases/metabolismo , Adenosina Difosfato Glucose/metabolismo , Adenosina Difosfato Ribose/metabolismo , Monofosfato de Adenosina/metabolismo , Animais , Fosfatos de Dinucleosídeos/metabolismo , Concentração de Íons de Hidrogênio , Magnésio/farmacologia , Manganês/farmacologia , NAD/metabolismo , Pirofosfatases/isolamento & purificação , Ratos , Especificidade por SubstratoRESUMO
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.
RESUMO
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.
Assuntos
Ascite/imunologia , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Cirrose Hepática/imunologia , Albumina Sérica/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Ascite/diagnóstico , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/imunologia , Proteínas Sanguíneas/metabolismo , Feminino , Humanos , Cirrose Hepática/diagnóstico , Masculino , Peritonite/diagnóstico , Peritonite/imunologia , Valores de Referência , Fatores de RiscoRESUMO
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.
Assuntos
Uremia/complicações , Verapamil/intoxicação , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Preparações de Ação Retardada , Relação Dose-Resposta a Droga , Bloqueio Cardíaco/induzido quimicamente , Humanos , Hipoglicemia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Verapamil/administração & dosagemRESUMO
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.
Assuntos
Injúria Renal Aguda/induzido quimicamente , Ácidos Aminossalicílicos/efeitos adversos , Anti-Inflamatórios não Esteroides/efeitos adversos , Doença de Crohn/complicações , Injúria Renal Aguda/diagnóstico , Adulto , Doença de Crohn/tratamento farmacológico , Feminino , Humanos , Testes de Função Renal , MesalaminaRESUMO
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.
Assuntos
Carcinoma de Células Escamosas/diagnóstico , Leucemia Linfocítica Crônica de Células B/diagnóstico , Neoplasias Pulmonares/diagnóstico , Segunda Neoplasia Primária/diagnóstico , Idoso , Humanos , MasculinoRESUMO
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.
Assuntos
Veia Axilar , Cateterismo Venoso Central/métodos , Ultrassonografia de Intervenção , Idoso , Clavícula , Feminino , Humanos , MasculinoRESUMO
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.
Assuntos
Assistência ao Convalescente , Alta do Paciente , Educação de Pacientes como Assunto , Barreiras de Comunicação , Compreensão , Aconselhamento , Estudos Transversais , Comportamento Alimentar , Hospitais Gerais , Humanos , Idioma , Estilo de Vida , Medicina , Estudos de Amostragem , EspanhaAssuntos
Colestase/etiologia , Equinococose/complicações , Pancreatopatias/complicações , Diagnóstico Diferencial , Equinococose/diagnóstico , Equinococose/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Cisto Pancreático/diagnóstico , Pancreatopatias/diagnóstico , Pancreatopatias/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico , Tomografia Computadorizada por Raios XRESUMO
Introducción: la mononucleosis infecciosa (MI) es una enfermedad frecuente en la infancia. Nos planteamos comparar la serie blanca de niños con sospecha de MI, en función de la serología positiva/negativa para virus Epstein-Barr (VEB), citomegalovirus (CMV) y Paul-Bunnell. Material y métodos: estudio descriptivo transversal. Se revisaron niños atendidos en Urgencias en 2010-2011, con diagnóstico de síndrome mononucleósico y serología positiva para VEB o CMV e igual número de niños con serologías negativas como grupo de control. Se compararon variables epidemiológicas, clínicas y serológicas. Resultados: se obtuvieron 50 niños con serologías positivas y 50 niños con serologías negativas (edad media de 5,81 años). Tuvieron serología positiva para VEB 44 niños, 2 para CMV y 4 para ambos. De los 48 niños con serología positiva para VEB, 26 eran Paul-Bunnell negativos y 22 positivos, siendo estos 22 niños el total de Paul-Bunnell positivos. La media de linfocitos, monocitos y basófilos fue mayor en niños con serología positiva para VEB y los neutrófilos fueron más bajos. En los dos casos con CMV positivo encontramos cifras de neutrófilos totales mayores. Ninguna edad se asoció con mayor probabilidad de VEB y Paul-Bunnell positivos. Conclusiones: existe predominio de linfocitos, monocitos y basófilos en niños con MI por VEB. El descenso de neutrófilos es la única variación analítica en los niños con MI por CMV. Estos valores analíticos pueden orientarnos en el diagnóstico de MI. Todos los niños con Paul-Bunnell positivo tenían positividad para el VEB sin relación con la edad (AU)
Introduction: the infectious mononucleosis (IM) is a common disease in childhood. We propose to compare the white series of children with suspected IM, based on serology positive/negative for Epstein -Barr Virus (EBV), Cytomegalovirus (CMV) and Paul- Bunnell. Material and methods: descriptive study. Children were reviewed, taken to hospital in 2010-2011, diagnosed with mononucleosis syndrome and positive serology for EBV or CMV, and equal number of children who were seronegative control group. Epidemiology, clinical and serological variables were compared. Results: there were 50 children with positive serology and 50 negative children (mean age 5.81 years ). EBV serology were 44 children, 2 and 4 both CMV. Of the 48 children with positive serology for EBV, 26 were negative Paul- Bunnell and 22 positive, and these 22 children total positive Paul-Bunnell. The average number of lymphocytes, monocytes and basophils was higher in children with positive serology for EBV and neutrophils were lower. Children were CMV negative but elevated neutrophils. No age was associated with increased likelihood of EBV and Paul- Bunnell positive. Conclusions: there is a predominance of lymphocytes, monocytes and basophils in children with EBV IM. The increase in neutrophils is the only analytical variation in children with CMV IM. These analytical values can guide the diagnosis of IM. All children with positive Paul- Bunnell positive for EBV had no relation with age (AU)
Assuntos
Humanos , Masculino , Feminino , Criança , Herpesvirus Humano 4/isolamento & purificação , Mononucleose Infecciosa/diagnóstico , Diagnóstico Diferencial , Infecções por Vírus Epstein-Barr/diagnóstico , Citomegalovirus/isolamento & purificação , Imunoglobulina M/isolamento & purificação , Sorologia/instrumentação , Sorologia/métodos , Proteínas do CapsídeoRESUMO
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.
Assuntos
Dor de Ombro , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Atenção Primária à Saúde , Dor de Ombro/diagnóstico , Dor de Ombro/terapiaRESUMO
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.