Preparation of riboflavin 4',5'-cyclic phosphate by incubation of flavin-adenine dinucleotide with Mn2+ in the absence of riboflavin 5'-phosphate cyclase.
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Animals↗
Biomedical subjects
R M Pinto
Publications and source records attributed to R M Pinto.
On the rugose area and caudal papillae distribution in Dirofilaria immitis (Leidy, 1856) Railliet & Henry, 1911, by scanning electron microscopy.
The objective of this study was to obtain a better characterization of Dirofilaria immitis (Leidy, 1856) Railliet & Henry, 1911, in Brazil, ratifying previous accounts and adding new data on the rugose area on the ventral surface of the spiralled posterior portion of males observed by scanning electron microscopy, which presents a different arrangement compared to other species of the genus, and differs also from the genera Litomosoides Chandler, 1931, and Wuchereria Silva Araújo, 1877, adding another taxonomic character to Dirofilariinae and Onchocercinae. Scanning electron microscopy studies also showed some aspects of the distribution of caudal papillae in D. immitis that have not been described before.
Animals↗
Enzymic formation of riboflavin 4',5'-cyclic phosphate from FAD: evidence for a specific low-Km FMN cyclase in rat liver1.
An enzyme activity splitting FAD to AMP and riboflavin 4',5'-cyclic phosphate (4',5'-cFMN), with a Km of 6-8 microM, was partially purified from the cytosolic fraction of rat liver homogenates. 4', 5'-cFMN was characterized by enzyme, HPLC, UV-visible and NMR spectroscopic analyses. The data suggest that a novel enzyme, tentatively named FAD-AMP lyase (cyclizing) or FMN cyclase, is involved. Also, 4',5'-cFMN was hydrolysed to 5'-FMN by a rat liver cyclic phosphodiesterase. The results indicate a novel enzymic pathway for flavins in mammals, and support the biological relevance of 4',5'-cFMN, perhaps as a flavocoenzyme or a regulatory signal.
Adenosine Monophosphate↗
Nitric oxide and human thermal injury short term outcome.
Nitric oxide (NO) is an important mediator in numerous physiological and pathophysiological events. After thermal injury an increase in plasma and urinary levels has been observed. The real importance of this fact is unknown. The stable NO derivatives (NO2-/NO3-) plasma concentrations were determined in 27 burned patients admitted to the Burn Unit at Santa Maria Hospital in Lisbon at first, third, fifth, seventh, ninth and 15th days and the values were compared with healthy controls (n=9). A significant increase (P<0.05) in burn patient determinations upon admission was found. The patients with inhalation injury revealed greater values compared to the other patients with statistical significance at 5th day (P<0.05). The patients who died showed a NO increase (0.397+/-0.138 vs. 0.267+/-0.017, P> 0.1, day 1) with significance at day 5 (0.615+/-0.223 vs. 0.154+/-0.048, P<0.05). The determinations in patients with sepsis were higher than in the other patients (P<0.01) at day 3. No relation with total burned surface area (TBSA) was found. For the first time, considering burned patients, a significant increase of NO was found in patients who died, in patients with inhalation injury and in patients in sepsis. The possible role of NO in burn injury is discussed. The authors suggest the possible role of NO determination as an indicator of sepsis. The role of NO synthesis inhibitors is discussed. Further studies are needed to clarify these questions.
Adolescent↗
Treatment of acute idiopathic thrombocytopenic purpura in children. A retrospective evaluation of 120 cases.
Acute idiopathic thrombocytopenic purpura (AITP) in children is generally a benign disease with a high frequency of spontaneous remission. Nevertheless the debate over treating or not is still open, because of the high risk of hemorrhage as long as the platelet count remains below 20 x 10(9)/l. We have retrospectively evaluated 120 pediatric cases from our center, receiving different treatments at diagnosis: no treatment (76); IVIG: 400 mg/kg/d for 5 days (28); continuous oral PDN: 1-1.5 mg/kg/d for at least two weeks (16). No patients had been previously treated for AITP. Follow-up is up to fifty months. We found no significant differences as to the percentage of responses among the three groups. We conclude that waiting without treatment is safe and appropriate in most cases; whether the hemorrhagic risk suggests treatment, standard dose continuous oral PDN and IVIG may be equally effective, but IVIG may achieve a significantly faster rise in the platelet count. The timing of treatment and the cost/benefit ratio are discussed.
Acute Disease↗
On the "let-down" procedure in septorhinoplasty.
In septorhinoplasty, the classical modified and Cottle's technique may complement each other. The maxilla-premaxilla approach of Cottle can be an utmost tool. Combined "let-down" and "push-down" (LD/PD) procedures can be advantageous in case of: (1) lowering a prominent pyramid while preserving the original profile of the dorsum; (2) lowering a pyramid that, after removal with a rasp knife and scissors, remains too prominent; (3) equalizing a deviated bony vault; and (4) eliminating a cartilaginous hump while preserving the integrity of the upper lateral cartilage. Septum excisions should be done to provide space for LD/PD manoeuvres.
Female↗
Specific ADP-ribose pyrophosphatase from Artemia cysts and rat liver: effects of nitroprusside, fluoride and ionic strength.
One specific ADP-ribose pyrophosphatase (ADPRibase) has been identified in Artemia cysts, following a protocol that in rat liver allows the identification of three ADPRibases. Artemia ADPRibase resulted similar, but not identical, to rat liver ADPRibase-I with respect to known and novel properties disclosed in this work. In the presence of Mg2+, Artemia ADPRibase was highly specific for ADP-ribose and showed a low, 0.7 microM Km. Preincubation with the nitric oxide donor nitroprusside and dithiothreitol, elicited dose- and time-dependent, severalfold increase of Km and decrease of Vmax. At saturating ADP-ribose concentrations, fluoride was a strong inhibitor (IC50 approximately equal to 10-20 microM), whereas bringing ionic strength to 0.3-1.3 mol/l doubled the activity measured at lower or higher strengths. The novel fluoride and ionic strength effects were studied also with rat liver ADPRibase-I. Differences between the Artemia enzyme and ADPRibase-I concerned molecular weight (31,000 versus 38,500, respectively), Mn2+ ability to substitute for Mg2+ as the activating cation (better for the rat enzyme), and Vmax decrease by nitroprusside (not seen with the rat enzyme). The results are discussed in relation with the role of specific ADPRibases as protective factors limiting free ADP-ribose accumulation and protein glycation, and as targets for cytotoxic agents.
Animals↗
Probability of long-term disease-free survival for acute myeloid leukemia patients after first relapse: A single-centre experience.
BACKGROUND: Various polichemotherapy regimens, including either high- or intermediate-dose Ara-C, are generally utilized to reinduce remission in relapsed AML patients. After achieving second CR, bone marrow transplantation (either allogeneic or autologous) represents the treatment of choice for eligible patients, with the aim of prolonging remission duration and improving disease-free survival. PATIENTS AND METHODS: Fifty AML patients in first hematological relapse were treated with MEC regimen, consisting of a 6-day induction cycle [mitoxantrone 6 mg/m2/day, cytarabine (Ara-C) 1 g/m2/day and VP-16 80 mg/m2/day] followed by a 4-day cycle with the same drugs for patients achieving complete remission (CR); allogeneic or autologous bone marrow transplantation (BMT) were planned as post-consolidation treatment. RESULTS: Thirty-four patients (68%) achieved second CR, 3 (6%) died during induction and 13 were refractory. CR rate was significantly higher in patients with a first CR lasting > 6 months (82% vs. 41%, P < 0.001). Out of the 34 patients in CR after the 4-day cycle, 18 (53%) were not eligible to transplant and did not receive any further therapy and 16 (47%) received autologous (15 cases) or allogeneic (1 case) BMT at a median time of 2 months from second CR. Twenty-two patients relapsed after a median time of 6 months (range 1-31), 1 patient died from transplant-related toxicity and 11 are in continuous CR [7 out of 16 (44%) in the transplanted and 4 out of 11 (36%) in the non-transplanted group]. Overall survival and event-free survival for the 50 patients were 29% and 19% at 70 months, respectively. The disease-free survival for the 34 patients who obtained second CR is 29% projected at 69 months [41% at 69 months for 16 transplanted patients versus 18% at 49 months for the remaining 18 patients (P = 0.007)]. CONCLUSIONS: These results show that MEC followed by high-dose post-consolidation treatment is a promising approach in relapsed AML; however, alternative strategies are to be investigated for the relevant fraction of patients that, even achieving second CR, are not eligible for BMT.
Adolescent↗
Detection of infectious astroviruses in water.
A method based on the infection of CaCo-2 cells and molecular hybridization with a specific cDNA probe has been developed for the detection of infectious astroviruses in environmental samples. By this procedure wild-type astroviruses have been detected in water from an area where a concurrent gastroenteritis outbreak was reported.
Journal Article↗
Detection of infectious astroviruses in water.
Volume 62, no. 5, p. 1811, column 2, line 2: Reference "(16)" should read "(15)." Page 1812, column 1, line 17: "Willcocks and Carter (15)" should read "Willcocks et al. (14)." [This corrects the article on p. 1811 in vol. 62.].
Journal Article↗
Interpersonal deficits and time spent in exercise or active recreation.
This study was designed to investigate the hypothesis that people with interpersonal deficits would spend less time in exercise or active recreation. Participants completed a questionnaire about the time spent per week in exercise or active recreation as well as in other activities such as reading and watching television. They also completed a questionnaire designed to measure both interpersonal and cognitive-perceptual deficits. Interpersonal deficits measured were social anxiety, constricted affect, and lack of close friends. Cognitive-perceptual deficits measured were perceptual aberration, magical ideation, and ideas of reference. Analysis showed that interpersonal deficits were related to reduced time spent in exercise or active recreation. Cognitive-perceptual deficits were not associated with time spent in exercise or active recreation.
Adolescent↗
Inhibition and ADP-ribose pyrophosphatase-I by nitric-oxide-generating systems: a mechanism linking nitric oxide to processes dependent on free ADP-ribose.
Rat liver ADP-ribose pyrophosphatase-I (ADPRibase-I; EC 3.6.1.13) hydrolyzes ADP-ribose with high specificity and a low Km. Thus it can participate in the control of free ADP-ribose and nonenzymatic ADP-ribosylation of proteins. Here we show that ADPRibase-I was inactivated by acidified nitrite, whereas sodium nitroprusside (SNP) or 3-morpholinosydnonimine (SIN-1) at pH 7.5 produced a dose- and time-dependent Km increase from 0.5 microM to 2 microM. The effects of SNP and SIN-1 depended on the presence and concentration of dithiothreitol, pointing to S-nitrosylation of enzyme thiols. It is suggested that, by inhibiting ADPRibase-I, NO can stimulate nonenzymatic ADP-ribosylation of targets susceptible to micromolar free ADP-ribose. This is discussed in relation to apparently contradictory earlier reports on the role of NO in the ADP-ribosylation of actin.
Adenosine Diphosphate Ribose↗
Rat liver nucleoside diphosphosugar or diphosphoalcohol pyrophosphatases different from nucleotide pyrophosphatase or phosphodiesterase I: substrate specificities of Mg(2+)-and/or Mn(2+)-dependent hydrolases acting on ADP-ribose.
Three rat liver nucleotides(5') diphosphosugar (NDP-sugar) or nucleoside(5') diphosphoalcohol pyrophosphatases are described: two were previously identified in experiments measuring Mg(2+)-dependent ADP-ribose pyrophosphatase activity (Miró et al. (1989) FEBS Lett. 244, 123-126), and the other is a new, Mn(2+)-dependent ADP-ribose pyrophosphatase. They are resolved by ion-exchange chromatography, and differ by their substrate and cation specificities, KM values for ADP-ribose, pH-activity profiles, molecular weights and isoelectric points. The enzymes were tested for activity towards: reducing (ADP-ribose, IDP-ribose) and non-reducing NDP-sugars (ADP-glucose, ADP-mannose, GDP-mannose, UDP-mannose, UDP-glucose, UDP-xylose, CDP-glucose), CDP-alcohols (CDP-glycerol, CDP-ethanolamine, CDP-choline), dinucleotides (diadenosine pyrophosphate, NADH, NAD+, FAD), nucleoside(5') mono- and diphosphates (AMP, CMP, GMP, ADP, CDP) and dTMP p-nitrophenyl ester. Since the enzymes have not been purified to homogeneity, more than three pyrophosphatases may be present, but the co-purification of activities, thermal co-inactivation, and inhibition experiments give support to: (i) and ADP-ribose pyrophosphatase highly specific for ADP(IDP)-ribose in the presence of Mg2+, but active also on non-reducing ADP-hexoses and dinucleotides (not on NAD+) when Mg2+ was replaced with Mn2+; (ii) a Mn(2+)-dependent pyrophosphatase active on ADP(IDP)-ribose, dinucleotides and CDP-alcohols; (iii) a rather unspecific pyrophosphatase that, with Mg2+, was active on AMP(IMP)-containing NDP-sugars and dinucleotides (not on NAD+), and with Mn2+, was also active on non-adenine NDP-sugars and CDP-alcohols. The enzymes differ from nucleotide pyrophosphatase/phosphodiesterase-I (NPPase/PDEaseI) by their substrate specificities and by their cytosolic location and solubility in the absence of detergents. Although NPPase/PDEaseI is much more active in rat liver, its known location in the non-cytoplasmic sides of plasma and endoplasmic reticulum membranes, together with the known cytoplasmic synthesis of NDP-sugars and CDP-alcohols, permit the speculation that the pyrophosphatases studied in this work may have a cellular role.
Animals↗
Anti-hepatitis A virus antibody response elicited in mice by different forms of a synthetic VP1 peptide.
Peptide VP1 (11-25) of the capsid of hepatitis A virus was synthesized by the Fmoc-polyamide solid phase method, and administered to mice in different forms: (1) free, (2) encapsulated in multilamellar liposomes, (3) coupled to keyhole limpet hemocyanin (KHL), and (4) incorporated into a tetrameric branched lysine core. The highest anti-VP1 peptide responses were generated by synthetic peptides entrapped into liposomes and coupled to KLH. No anti-HAV response was generated with the free peptide, while all the other forms induced both anti-HAV and HAV-neutralizing antibodies. Maximum neutralization indices were observed in ascites from mice treated with liposome-entrapped and KLH peptides.
Adjuvants, Immunologic↗
Rat liver mitochondrial ADP-ribose pyrophosphatase in the matrix space with low Km for free ADP-ribose.
A study involving markers of subcellular and submitochondrial fractions, gradient centrifugation, latency measurements and extraction with digitonin, demonstrates the association of a specific ADP-ribose pyrophosphatase with rat liver mitochondria and its localization in the matrix space. The enzyme hydrolyses ADP-ribose to AMP, with a Km of 2-3 microM. The results support the occurrence of a specific turnover pathway for free ADP-ribose and its relevance in mitochondria.
Adenosine Diphosphate Ribose↗
Structures associated with the expression of rabies virus structural genes in insect cells.
When rabies virus structural genes were expressed in insect cells, major observed alterations were a high level of cytoplasmic vacuolization caused by the matrix protein M2 and the glycoprotein G. Ring-like structures, 16 nm in diameter, were observed in cell-free extracts from insect cells that expressed the N protein alone. Hexagonally shaped structures, 16-20 nm in diameter, and regular lattice aggregates of the same structures appeared on co-expression of N and M1 proteins. Co-expression of the four structural proteins led to the formation of cell surface blebs containing the structures corresponding to N and M1 proteins.
Animals↗
Malignant fibrous histiocytoma secondary to allogeneic bone marrow transplantation.
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Bone Marrow Transplantation↗
What does one do for the CML patient in relapse after allogeneic bone marrow transplantation?
The management of CML patients with some evidence of disease after BMT depends on the molecular, cytogenetic and hematological findings of relapse. Presently, a number of technical and biological problems do not allow to draw any definitive conclusion on the prognostic significance of Minimal Residual Disease detected by PCR. A positive PCR, particularly if observed late after BMT, leads to increase the frequency of cytogenetic examinations, but a therapeutic intervention is not justified. The criteria to define the cytogenetic relapse are not still established. Therefore it is difficult to interpret the reappearance of Ph-1 chromosome after BMT as disease recurrence invariably progressing towards the hematological phase. However, alpha-Interferon, donor buffy-coat infusion or their association should be considered in the treatment of patients for whom the cytogenetic relapse has been confirmed. The therapeutic approach to patients with hematological relapse is mainly depending on the phase of disease. The single, sequential or combined use of chemotherapy, alpha-IFN, donor buffy-coat infusion and second transplant has been shown to be effective in restoring donor hematopoiesis in several patients who relapsed either in chronic or advanced phase. Prospective, randomized, multicentre trials on CML relapse after BMT should be planned.
Antineoplastic Agents↗