Intermittent claudication in older patients: risk factors, cardiovascular comorbidity, and severity of peripheral arterial disease.
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Age Factors↗
Biomedical subjects
G Oliva
Publications and source records attributed to G Oliva.
Human phosphoglucose isomerase: expression, purification, crystallization and preliminary crystallographic analysis.
Phosphoglucose isomerase (PGI) is the second enzyme in the glycolytic pathway and catalyzes an aldose-ketose isomerization. Outside the cell, PGI has been found to function as both a cytokine and as a growth factor. The human pgi gene was cloned and the expressed enzyme was purified to homogeneity. Isomorphous crystals were obtained under two conditions and belong to the P2(1)2(1)2(1) space group, with unit-cell parameters a = 80.37, b = 107.54, c = 270.33 A. A 94.7% complete data set was obtained and processed to a limiting resolution of 2.6 A. The asymmetric unit contains two hPGI dimers according to density calculations, a self-rotation function map and molecular-replacement solution.
Crystallization↗
Crystallization and preliminary crystallographic studies of a phospholipase A2 from the venom of the Brazilian snake Bothrops moojeni.
A phospholipase A(2) purified from the venom of the snake Bothrops moojeni has been crystallized by vapour-diffusion techniques in hanging drops at 291 K. The crystals, which were grown in the absence of Ca(2+), belong to the cubic system, space group P432, with unit-cell parameters a = b = c = 91.86 A, and contain one molecule in the asymmetric unit (V(M) = 2.71 A(3) Da(-1)). X-ray diffraction experiments provide data to 2.35 A resolution collected on a rotating-anode home source at cryogenic temperatures. The structure has been solved via molecular-replacement techniques using a single monomer of the crystallographic structure of the phospholipase from the Western diamondback rattlesnake (Crotalus atrox) as a search model.
Animals↗
[Survey on the preoperative evaluation in Catalonian surgical centers. II. What is the attitude and opinion of the professionals involved?].
OBJECTIVE: Previous studies have provided evidence of the existence of differences in preoperative assessment practices and have questioned the usefulness of generalized testing for all patients. The objective of this study was to determine the attitudes and opinions of anesthesiologists and surgeons about their application of preoperative assessment procedures and their knowledge of the scientific principles underlying their practice. SUBJECTS AND METHODS: A questionnaire was mailed to 227 specialists in anesthesiology and postoperative intensive care, general and gastrointestinal surgery, orthopedic surgery and traumatology of all hospitals in Catalonia (Spain) with active operating theaters. RESULTS: The overall response rate was 61% of the surveyed population, with 86% of the Catalan hospitals represented. The medical literature supports the routine performance of a chest x-ray and an ECG in the opinion of 17 and 26% of the respondents, respectively. Those two procedures are always ordered by 43 and 37%, respectively, even if they believe that the medical literature does not support generalized application. Legal protection was given as the reason for routine ordering of preoperative tests in asymptomatic patients, and 89% believed that a protocol for selective preoperative assessment procedures would improve efficiency. CONCLUSIONS: This study reveals a discrepancy between the opinions of professionals involved in preoperative assessment and their real practice in Catalan hospitals, probably influenced by perceived need for legal protection.
Anesthesiology↗
[Survey on the preoperative evaluation in Catalonian surgical centers. I. What is the preoperative routine?].
OBJECTIVE: To describe the preoperative assessment procedures currently used in hospitals in Catalonia (Spain). SUBJECTS AND METHODS: The study population consisted of all heads of departments of anesthesiology, general and gastrointestinal surgery, orthopedic surgery and traumatology of hospitals and clinics in Catalonia with active operating theaters. Information was obtained by self-administered questionnaire prepared by an interdisciplinary team. RESULTS: Of the 227 questionnaires sent, 139 (61%) were answered and returned. A preoperative assessment visit was programmed according to 112 (81%) of the respondents and 123 (89.8%) reported following a protocol that included ordering preoperative tests. The same tests were ordered for all patients by 25% of the respondents. A chest film and an ECG were always ordered according to 61 and 65%, respectively, and always when the patient was over a certain age according to 36 and 32%, respectively. Coagulation and blood sugar tests and a complete blood workup were always ordered according to 94%, 95% and 89%, respectively. Tests were considered valid for less than six months by most. CONCLUSIONS: This survey provides evidence of widespread use of preoperative assessment, although application falls short of including all scheduled patients. According to these results, selective protocols for ordering complementary preoperative tests are rarely applied.
Age Factors↗
Influence of the histidine tail on the structure and activity of recombinant chlorocatechol 1,2-dioxygenase.
We present two efficient expression systems for the chlorocatechol 1, 2-dioxygenase (CCD) from Pseudomonas putida. In the first, CCD (encoded by the clcA gene) was expressed in the pETCLCA vector with the addition of an N-terminal histidine tail. After purification, the enzyme (CCD 6xHis) was proteolytically cleaved with thrombin to remove the His tail. The CD spectra of the cleaved and uncleaved enzymes present only minor differences, indicative of correct protein folding. However, the activity of CCD 6xHis, over a wide range of pH, was typically five times lower. This may be the result of steric hindrance caused by the histidine tail. These data are consistent with results obtained using an alternative construct employing a vector which produces a protein product devoid of the His tail. These results suggest that the His tail may induce subtle effects close to the active site which compromise the recovery of full biological activity.
Amino Acid Sequence↗
Combination antiretroviral therapy in human immunodeficiency virus-infected pregnant women.
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Antiviral Agents↗
Pyrano chalcones and a flavone from Neoraputia magnifica and their Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase-inhibitory activities.
The fruits of Neoraptua magnifica var. magnifica afforded three new flavonoids: 2'-hydroxy-4,4',-dimethoxy-5',6'-(2'',2''-dimethylpyrano)chalcone, 2'-hydroxy-3,4,4'-trimethoxy-5',6'-(2'',2''-dimethylpyrano)chalcone, and 3',4'-methylenedioxy-5,7-dimethoxyflavone which were identified on the basis of spectroscopic methods. The known flavonoids 2'-hydroxy-3,4,4',5-tetramethoxy-5',6'-(2'',2''-dimethylpyrano)chalcone, 2'-hydroxy-3,4,4',5,6'-pentamethoxychalcone, 3',4'-methylenedioxy-5,6,7-trimethoxyflavone, 3',4'-methylenedioxy-5',5,6,7-tetramethoxyflavone, 3',4',5',5,7-pentamethoxyflavanone and 3',4',5'5,7-pentamethoxyflavone were also identified. The latter flavone was the most active as glyceraldehyde-3-phosphate dehydrogenase-inhibitor.
Animals↗
Biochemical indicators of bone metabolic activity in buffalo (Bubalus bubalis) during late pregnancy and early lactation.
Blood levels of calcium, inorganic phosphorus, magnesium, osteocalcin, intact parathyroid hormone, calcitonin, alkaline phosphatase activity, creatinine and thyroid hormones were estimated in 10 healthy buffalo during late pregnancy (30, 15 days and 7 days before calving), within 12 h after calving and 7-15-30-45 and 60 days after calving. The almost constant serum levels of calcium, phosphorus, intact parathyroid hormone, and the low calcitonin concentration indicate that these buffalo need to utilize only a little of their endogenous mineral resources. Bone-turnover could be demonstrated by variations in the serum levels of osteocalcin and alkaline phosphatase activity. A study of these bone markers could be useful for other research purposes and for future clinical application in pathological conditions.
Alkaline Phosphatase↗
Crystallization and preliminary crystallographic analysis of N-acetylglucosamine 6-phosphate deacetylase from Escherichia coli.
N-Acetylglucosamine 6-phosphate deacetylase (E.C. 3.5.1.25), an enzyme from Escherichia coli involved in aminosugar catabolism, has been crystallized by the vapour-diffusion technique using phosphate as precipitant. X-ray diffraction experiments show the crystals to belong to the orthorhombic crystal system, with space group P2(1)2(1)2. The unit-cell parameters are a = 82.09 (2), b = 114.50 (1), c = 80.17 (1) A. The crystals diffract to a maximum resolution of 1.8 A and an initial data set was collected to 2.0 A.
Amidohydrolases↗
[Is total parenteral nutrition necessary in patients subjected to radical cystectomy?] .
BACKGROUND: The aim of the study is to evaluate the nutritional stats in candidates to radical cystectomy in order to minimize post-operative complications. METHODS: The evaluation is carried out on the basis of anthropometric, bio-humoral and immunologic indexes in a retrospective analysis of patients who underwent major urologic surgery during the last two years. Twenty cases of invasive bladder cancer (mean age 71 years) who underwent radical cystectomy have been studied: in 13 cases urinary diversion by Camey II technique, in 7 cases by Bricker technique has been performed. In 5 cases of orthotopic neo-bladder, endovenous parenteral protein sparing nutrition was carried out for 4 days, in the remaining 15 cases glucidic and saline solutions have been administered. RESULTS: In all the 20 evaluated patients post-operative complications have not been observed. CONCLUSIONS: On the basis of the data obtained, the conclusion is drawn that patients with bladder cancer are generally not so malnourished to need an artificial feeding regimen. Considering the urinary tract substitution effects on renal function and metabolism, particularly for the role of glucose on proximal and distal tubule the usefulness of administering only glucidic solutions and maintaining a good diuresis is underlined.
Aged↗
Isolation and structural characterization of a cytotoxic L-amino acid oxidase from Agkistrodon contortrix laticinctus snake venom: preliminary crystallographic data.
We have purified a cytotoxic L-amino acid oxidase (LAO) from Agkistrodon contortrix laticinctus snake venom by means of Superdex-200 gel filtration, followed by phenyl-Sepharose CL-4B chromatography. The purified enzyme (ACL LAO) is a dimer on gel filtration, with a M(r) of 60,000 for the monomer as estimated by SDS-PAGE. LAO activity was tested against 15 amino acids, but only 9 were oxidized by the enzyme, suggesting that it presents some degree of specificity. ACL LAO has apoptosis-inducing activity in an HL-60 cell culture assay. After 24 h treatment with 25 micrograms/ml of ACL LAO, the typical DNA fragmentation pattern of apoptotic cells was observed on agarose gel electrophoresis. NMR analysis showed the presence of a flavin mononucleotide prosthetic group. To solve its 3-D structure, crystals of the purified protein were grown in 0.1 M Tris-HCl, pH 8.5, and 2 M (NH(4))(2)SO(4). Diffraction data collected to 3.5 A showed that the protein crystallized in the tetragonal system, with unit cell a = b = 103.22 A, c = 183.45 A. This is the first report of preliminary crystallization data for a snake venom L-amino acid oxidase.
Agkistrodon↗
The allosteric transition of glucosamine-6-phosphate deaminase: the structure of the T state at 2.3 A resolution.
BACKGROUND: The allosteric hexameric enzyme glucosamine-6-phosphate deaminase from Escherichia coli catalyses the regulatory step of N-acetylglucosamine catabolism, which consists of the isomerisation and deamination of glucosamine 6-phosphate (GlcN6P) to form fructose 6-phosphate (Fru6P) and ammonia. The reversibility of the catalysis and its rapid-equilibrium random kinetic mechanism, among other properties, make this enzyme a good model for studying allosteric processes. RESULTS: Here we present the structure of P6(3)22 crystals, obtained in sodium acetate, of GlcN6P deaminase in its ligand-free T state. These crystals are very sensitive to X-ray radiation and have a high (78%) solvent content. The activesite lid (residues 162-185) is highly disordered in the T conformer; this may contribute significantly to the free-energy change of the whole allosteric transition. Comparison of the structure with the crystallographic coordinates of the R conformer (Brookhaven Protein Data Bank entry 1 dea) allows us to describe the geometrical changes associated with the allosteric transition as the movement of two rigid entities within each monomer. The active site, located in a deep cleft between these two rigid entities, presents a more open geometry in the T conformer than in the R conformer. CONCLUSIONS: The differences in active-site geometry are related to alterations in the substrate-binding properties associated with the allosteric transition. The rigid nature of the two mobile structural units of each monomer seems to be essential in order to explain the observed kinetics of the deaminase hexamer. The triggers for both the homotropic and heterotropic allosteric transitions are discussed and particular residues are assigned to these functions. A structural basis for an entropic term in the allosteric transition is an interesting new feature that emerges from this study.
Aldose-Ketose Isomerases↗
Iatrogenic reno-jejunal fistula.
The development of a reno-jejunal fistula following a Roux-en-Y cystojejunostomy for an incorrectly diagnosed pancreatic pseudocyst is described. Up to now, this is the second case of iatrogenic reno-jejunal fistula reported in literature. Reno-jejunal fistulas are exceedingly rare and are usually consequences of urologic pathologies of infectious origin. Reno-jejunal fistulas of iatrogenic origin are even rarer, only one case being referred in literature [1]. Herein the second case is reported.
Adult↗
[Prevention and early diagnosis of testicular neoplasms].
Aetiology of testicular cancer is still poorly characterized, so the prevention is unlikely to achieve. A fundamental issue is early detection as delay in presentation is a common feature in patients affected by this disease. Moreover there is much evidence suggesting a significant association between delay in diagnosis and clinical stage at presentation particularly for nonseminomas. 176 valuable patients with non seminomatous germ cell tumors of the testis had a clearly identifiable interval from first symptoms until diagnosis; mean delay was 13.9 weeks, and there was a correlation between difference in delay of I clinical stage patients (mean: 10.0 weeks) and III stage patients (mean: 18.6 weeks) ANOVA: p < 0.035. These data suggest that encouraging programmes in order to provide more informations on testicular cancer and testicular self examination (TSE) may contribute to reduce the number of young men requiring toxic treatment and major surgery and even may reduce mortality.
Humans↗
[Synchronous and metachronous bilateral tumors of the testis: a single institution experience of 11 cases and review of the literature].
Bilateral testicular tumors represent a very rare event and account for 2.7% of all testicular neoplasms. 15% of bilateral testicular tumors occurs simultaneously in both testicles, but in 85% of cases the second neoplasia appears in the remaining testicles of patients affected by unilateral testicular tumor after a very variable period of time. The aim of this work was to value our experience on 11 cases of bilateral testis tumors: six arised simultaneously in both gonads (five germ cell tumors and one Leydig cell tumor) and five with metachronous appearance (all germ cell tumors). A comprehensive valuation has been made considering other cases reported in literature until 1996, in order to identify predisposing conditions to bilateral disease. Examining separately synchronous and metachronous neoplasms, as far as we know, only 218 cases of simultaneous bilateral testicular tumors are reported in literature, and most of them are pure seminomas; however, after 1988 this result has been reversed in favour of neoplasms with non-seminomatous elements: this data suggests inadequate classification in the past. Moreover, considering 243 cases of metachronous neoplasms, 126 of them (51.9%) began as non-seminomatous tumors: this disagrees with an old belief that patients affected by seminoma are more prone to develop a second tumor in the remaining testicle. It has been also possible to confirm that testis sparing surgery allows to maintain both fertility and endocrinous function. This technique can be used in any potentially benign neoplasms (as Leydig cell tumors) while the same treatment modality, although already reported in literature, needs more experience to be considered as a successful therapy for germinal tumors.
Adolescent↗
What high-risk women are telling us about access to primary and reproductive health care and HIV prevention services.
Focus group discussions on barriers to health care and attitudes toward family planning, reproductive health services, and condom use were conducted with 63 women at high risk for HIV due to their own injection drug use, sex with injection drug users, sex industry work, or a history of multiple sexually transmitted diseases. Barriers identified include the high cost of health care, perceived poor quality of care and experiences of discrimination and stigmatization, geographic accessibility, fear of legal/social services punitive actions, misperceptions about the efficacy of birth control methods and condom usage, lack of sterilization services, and lack of male involvement. Where possible, findings from the focus groups are supported with quantitative survey data from a sample of high-risk women (n = 723). Recommendations are made for improving care for high-risk women.
Adult↗
On the choice of an optimal wavelength in macromolecular crystallography.
Potential benefits of using short X-ray wavelengths for protein crystal data collection arise from a reduction in absorption errors and a decrease in radiation damage of a sample. On the other hand, at longer wavelengths one may benefit from an increase in scattering efficiency of a crystal and an increase in intensity of an incident beam at a given synchrotron beamline. For small and frozen crystals the negative effects of absorption and radiation damage would be minimized which may shift the balance of interests towards the use of longer wavelengths. Experiments carried out at EMBL beamlines at DESY (Hamburg) show an advantage of using wavelengths longer than 1 A for data collection from crystals of up to 0.5 mm.
Crystallography, X-Ray↗