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Biomedical subjects

P Conforti

Publications and source records attributed to P Conforti.

At least 19 recordsLinked to original sources
PubMed2006

Dioxygenation of naphthalene by Pseudomonas fluorescens N3 dioxygenase: optimization of the process parameters.

The bioconversion of naphthalene to the 1,2-dihydro-1,2-dihydroxy derivative was performed in good yield using an Escherichia coli recombinant strain carrying Pseudomonas fluorescens N3 dioxygenase. However, the efficiency of such transformation is affected by many process parameters, and their optimization is essential to the scaling up of the process. The following process parameters were considered for optimization: cell concentration together with the corresponding glucose concentration (DCW/L); pH of medium; temperature; stirring speed; air flow; substrate concentration; Fe(2+) concentration; microelements concentration; reaction volume. We used a two-step multivariate experimental design to select important variables and assign them optimal values. The most significant parameters were selected by adopting a Plackett-Burman design, and were then correlated, using a full factorial design, with the experimental results. The experimental results illustrate that the optimized process of recombinant whole cell biotransformation in two-liquid phase systems enhances the naphthalene dihydrodiol yield threefold. This biotransformation opens the way to future experiments involving different substrates.

Bacterial Proteins↗
PubMed2001

Comparison of two cysteine endopeptidases from latices of Morrenia brachystephana Griseb. and Morrenia odorata (Hook et Arn.) Lindley (Asclepiadaceae).

The properties of morrenain b II, a proteinase isolated from the latex of Morrenia brachystephana, were compared with those of morrenain o II, a proteinase obtained from the latex of Morrenia odorata. Both peptidases were purified to homogeneity by acetone precipitation followed by cation exchange chromatography. The enzymes have pI values higher than 9.3 and similar molecular masses (close to 26 kDa) as determined by SDS-PAGE. They display maximum proteolytic activity within an alkaline pH range, and also exhibit esterolytic activity. The N-terminal sequences of morrenain o II and morrenain b II show a high degree of homology between each other and to other cysteine plant proteinases.

Amino Acid Sequence↗
PubMed2000

What is the cost of a healthy diet in terms of achieving RDAs?

OBJECTIVE: Assessing how the Italian average food pattern would be affected in terms of consumption structure and expenditure by the adoption of nutritional prescriptions. DESIGN: A linear programming model with nutritional and food habits constraints was employed to generate a pattern following recommended daily allowances (RDAs) and nutritional guidelines provided for the Italian population. SETTING: Food consumption data from ISTAT Household Budget Survey of Italian population. SUBJECTS: Italian families investigated by the Family Budget Survey of the National Institute of Statistics. RESULTS: Compared to actual behaviour, the pattern generated by the model implies an increased consumption of vegetables, pasta, rice and fresh fish, and a decreased consumption of meats, bread, sugars and cakes, and especially fats and oils. At given prices, total expenditure is lower than actual expenditure. CONCLUSIONS: Differences between actual behaviour and the generated pattern are consistent with long-term trends in food consumption. The adoption of RDAs is unlikely to result in an increased food expenditure.

Budgets↗
PubMed1994

Use of multivariate analysis to compare antimicrobial agents on the basis of in vitro activity data.

Multivariate techniques such as principal component analysis or similar factor analysis help in analyses of the simultaneous interrelationships among several variables. A comparative multivariate analysis on the in vitro activities of eight antimicrobial agents, including the novel molecule daptomycin, is presented. Multivariate analysis detects components or factors and establishes connections among antimicrobial agents on the basis of their different levels of participation in each factor. The first principal component was dominated by vancomycin, teicoplanin, and rifampin (0.94344, 0.92792, and 0.72127, respectively). The second principal component showed strong effects from imipenem, gentamicin, and cephalothin (0.87922, 0.86126, and 0.68870, respectively). Daptomycin stood out alone in the third principal component (0.83983). The first three components defined 81.5% of the total variance and could easily be represented graphically in a three-dimensional scatter plot. In this graphic representation, the eight antimicrobial agents clustered in three different spatial regions; daptomycin occupied a separate spatial position. The use of multivariate analysis offers a different approach to determination of the in vitro activities of new antimicrobial agents and adds some new data on the relationships among different classes. Notwithstanding its limitations, the application of these methods in microbiology and drug development could be an additional tool for use in processing information.

Anti-Bacterial Agents↗
PubMed1992

Clinical economics: a method for prospective health resource data collection.

Information about the economic benefit of new drugs is becoming increasingly important for formulary considerations, reimbursement policies and related considerations. Although economic benefits of drugs have been analysed and reported, the economic benefits of drugs have rarely been examined in the course of randomised therapeutic trials. We designed a modular survey instrument, the Resource Utilisation Survey (RUS), to collect economic outcomes in prospective trials. A pilot test of the RUS was conducted using clinical trial methods in a study of nizatidine versus placebo in preventing ulcers induced by nonsteroidal anti-inflammatory drugs. The purpose of the pilot study was to evaluate the RUS instrument and corresponding study design issues in clinical trials for either acute or chronic diseases. With the lessons learned from the pilot study, the RUS has been used successfully in other ongoing clinical trials.

Economics, Pharmaceutical↗
PubMed1991

Microsurgical management of suprasellar and intraventricular meningiomas.

A series of 78 intracranial meningiomas (68 suprasellar, 10 intraventricular) were operated on in our Institute after the advent of the operating microscope. In our review, we discuss the microsurgical technical problems related to the preservation of vascular and brain structures in the removal of intraventricular and parasellar meningiomas. Basic diagnostic criteria to plan correctly the surgical approach will be emphasized. Mortality and morbidity in parasellar meningiomas is, in our opinion, related to the experience of the surgeon in using the operating microscope rather then in using the laser and CUSA. We will also discuss the utility of preoperative embolization of the lesion as well as the indications for intraoperative EC/IC bypass. Finally, morbidity and mortality related to different approaches for intraventricular meningiomas will be discussed.

Adult↗
PubMed1989

Biosynthetic human growth hormone: current status and future questions.

Human growth hormone derived from human pituitaries resulted in excellent growth in children with growth hormone deficiency but limited supplies in many countries prevented treatment of all children, delayed the onset of therapy, and/or forced the use of doses that may have been less than optimal. Recent advances in technology allow the production of byosynthetic human growth hormone (hGH) by recombinant methods resulting in increased supplies of hormone. More than 200 previously untreated children with growth hormone deficiency have been evaluated for two years or longer while receiving biosynthetic natural sequence hGH (somatropin). The mean growth velocity of 3.6 cm/yr prior to therapy increased to 8.8 cm/yr after one year and 7.25 cm/yr in the second year. Growth response was inversely related to age when calculated as cm/yr. This response paralleled the normal decrease in growth velocity as children approach puberty. Children with hGH deficiency who had previously received replacement hGH were enrolled in a double-blind study using either 0.06 or 0.10 mg/kg thrice weekly for 12 months. Growth rate was significantly greater with the higher dose during the first six months but not during the second six month period. The use of a higher dose of hGH must be individualized as not all patients have accelerated growth with the increased dose and the mean group response is not permanent. Multiple questions remain unanswered after three decades of treating growth hormone deficiency. Are the current criteria for diagnosis of growth hormone deficiency appropriate? What dose of hGH is correct? Do children need increases in replacement therapy as their height approaches normal?(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1988

Quantitative assessment of blood-brain barrier permeability in multiple sclerosis using 68-Ga-EDTA and positron emission tomography.

Fifteen patients with definite multiple sclerosis were examined with high volume delayed (HVD) CT scan and positron emission tomography (PET) using 68-Ga-EDTA as a tracer. The passage of 68-Ga-EDTA across the blood-brain barrier (BBB) was measured by using multiple graphical analysis. This method permits the simultaneous calculation of a blood to brain influx constant Ki (ml/g-1 min-1) and of the plasma volume Vp (ml/g-1). Focal areas of abnormal CT enhancement and pathological accumulation of 68-Ga-EDTA were visualised in four patients who were all examined during a clinical exacerbation of the disease. The mean Ki value measured in these areas was 12.5, SD 3.4 indicating a moderate but significant increase of BBB permeability compared with the value found in normal tissue (3.2, SD 0.9). No parallel increase in Vp values was found in these pathological areas. Quantitative data obtained with PET seems to provide further insight into the study of BBB function in multiple sclerosis.

Adolescent↗
PubMed1982

Relation of cerebral vasospasm to operative findings of subarachnoid blood around ruptured aneurysms.

An investigation was carried out in 28 patients in order to evaluate the relationship between angiographically documented vasospasm, amount of subarachnoid blood found at surgery around ruptured intracranial aneurysms, and delayed ischaemic deficits. Angiography was performed at time intervals ranging between 5 and 17 days, and surgery not later than 21 days following subarachnoid haemorrhage. The absence of subarachnoid clots was associated in ten patients, with no or minor vasospasm and no or mild neurological deficits. Thin clots were found in eight patients; one of them had no vasospasm, six had minor vasospasm, and one showed severe vessel narrowing. Major clinical signs were absent in these cases. All ten patients with thick clots developed severe vasospasm, and eight of them severe neurological signs. The important aetiological role of local subarachnoid clots developed severe vasospasm, and eight of them severe neurological signs. The important aetiological role of local subarachnoid clots in determining vasospasm in emphasized in view of surgical timing.

Adult↗
PubMed1981

Dynamics of endothelial repair in end-to-side microsurgical carotid anastomoses in rats: a scanning electron microscopic evaluation.

A scanning electron microscopic (SEM) investigation of endothelial behavior, following carotid end-to-side microsurgical anastomoses, was carried out in twenty-four Sprague-Dawley rats. From the hemodynamic point of view, the experimental model used in this study involved a bidirectional flow in the recipient vessel. Following surgery, specimens were collected at intervals varying from 15 minutes to 14 days. The thrombus formation was particularly evident in the first 45 minutes, and then gradually disappeared. Evidence showed that the new endothelial cells, covering the defect at the site of the suture, originate from the normal endothelium. Regenerated endothelial cells showed particular morphological features which are expressions of high metabolic rate and of active cell movement. Endothelial repair on the suture line began 3 days after the operation, and was completed there earlier than it was on the stitches. An accurate microsurgical technique is needed to avoid an increased thrombus formation and delayed re-endothelialization.

Animals↗
PubMed1981

SEM evaluation of endothelial changes following end-to-side microvascular anastomoses in rats.

A scanning electron microscopic (SEM) study was carried out to evaluate the endothelial changes in carotid end-to-side microsurgical anastomoses. This procedure, associated with occlusion of the brachiocephalic trunk, was performed in 24 Sprague-Dawley rats. The animals were sacrificed at time intervals ranging between 15 minutes and 14 days after surgery. The specimens were collected after perfusion-fixation in vivo and treated for SEM observations. The findings show that the first 45 minutes are the most critical time for thrombus formation. Reendothelialization could be detected at 3 days after the microsurgical procedure. Endothelial regeneration occurred earlier on the suture line than on the stitches, documented by the migration and morphological changes of the endothelial cells advancing from the normal endothelium to cover the defect and the suture material. The repair was usually completed within 14 days. Damage of the inner vascular wall, related to minor failures of the microsurgical technique, appears to be a cause of delayed reendothelialization.

Animals↗