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C Baraldi

Publications and source records attributed to C Baraldi.

32 records · Page 2Linked to original sources

Compton scattering profile for in vivo XRF techniques.

The contribution from single Compton scattered photons to the background in in vivo x-ray fluorescence analysis is evaluated by taking into account the energy broadening of the scattered photons which reflects the momentum distribution of the target electrons. A general-purpose Monte Carlo evaluation of multiple scattering components, as well as accurate experimental verifications with 59.54 keV photons impinging on various targets of interest for real-life irradiation, confirm that the single Compton scattering profiles of the elements composing the biological matrix dominate the trend and amplitude of the background in the region of interest with near-backscatter configurations. Step features are likewise explained in terms of single Compton phenomenology. Other probable sources of background, such as photoelectron Bremsstrahlung and pile-up distribution, are studied both theoretically and experimentally in order to compare their amplitude and features with those of single Compton scattered photon profiles.

Bone and Bones↗

[Modern technics of intracavitary curietherapy of cervical carcinoma].

The authors set out the technical innovations which are being used to comply with the three classical aims of endocavitary curietherapy for cervical cancer: the personalization of the irradiation device, protection of staff against exposure risks due to ionizing radiations, planning and control of the irradiation conditions. The personalization of the irradiation device is achieved by preparing a specially shaped vaginal applicator for each patient, and staff protection is ensured by the use of remote-loading techniques and closed circuit television control for in-patients. The planning of the treatments answers to the logic of reproducing the usual curie therapy method with conventional radium-226 sources. In order to control the irradiation conditions, at least the essential part of the treatments must be recognized and expressed: equivalent radium milligrams per hour (MRA h), dose rate (Gy h-1), dimensions of the treated volume and space distribution of the dose.

Brachytherapy↗

Molecular coherent scattering data for tissue in photon transport Monte Carlo codes.

The suitability of introducing molecular interference effects into coherent scattering phenomenology is considered here in the case of X and gamma photon transport in biological tissues. In order to make its implementation practicable in most of the existing open user Monte Carlo codes, a self-consistent basic set of tabulations for the linear differential scattering coefficient was proposed. The tabulations were critically reviewed by testing their validity over the entire range of the momentum transfer variable from 0 to 10(10) nm(-1). Implementation in three different Monte Carlo codes was performed, and they proved to be reliable.

Adipose Tissue↗

Endogenous benzodiazepines.

The existence of endogenous benzodiazepines such as diazepam and nordiazepam has been provided in human blood and brains as well as in medicinal plants and foods. It must be stressed, however, that in plasma and brain tissue there are also other benzodiazepine-like compounds termed 'endozepines' which are not halogenated. A synthetic pathway for the production of benzodiazepine-like compounds and endozepines has not yet been found, hence it may be surmised that these compounds could be of exogenous source. Changes in the level of endogenous circulating benzodiazepines due to food or drug ingestion could be responsible for pathological conditions. Clinical experiments were designed in order to study the levels of the endogenous benzodiazepines in vegetables and in the blood of control subjects and of cirrhotic patients. These patients accumulate benzodiazepines because of decreased liver metabolization capacity and impaired renal secretion, reaching plasma concentrations similar to those recorded in commercial benzodiazepine consumers.

Anti-Inflammatory Agents, Non-Steroidal↗

[Vascular access validity and treatment efficiency in hemodialysis].

The vascular access is the "Achille's heel" of the modern hemodialysis. In order to obtain a good depuration, the blood flow in dialysis must be of 250-300 mL/min, at least. The procedures for the preparation and their complications are cause of the 25% of the hospital admissions in patients with chronic uremia in substitutive therapy. Gold standard is still represented from the distal arteriovenous fistulas of Cimino and Brescia. The alternatives to the native veins as the syntetic graft and the tunneled central venous catheteters or the Dialock system, revealed useful in the patients that have exausted the superficial veins, but are of second choice. The native fistula has an advanced validity, demonstrated from lower risk of mortality in the patients who use it, diabetic or not. These affirmations come just from USA, where the arteriovenous grafts prevail and the percentage of central venous catheters is elevated. Thrombosis, infections and reduced depurative efficiency are the main causes. In the Dialysis Unit of Mantova we adopted an aggressive approach to the construction of distal fistula. Out of 172 patients in chronic hemodialysis, 165 use an arterovenous fistula, 4 an arterovenous grafts (PTFE) and 3 a tunnelled central venous catheters (2 Permcath and 1 Tesio). The surgical activity between 1987 and 2001 included 858 procedures on 516 patients (medium ages 59.1 years): Among these, 815 are created from native veins, 28 by arterovenous graft fistulas and 15 with tunnelled hemodialysis catheters. Our current strategy recommended to candidate to permanent venous catheter only patients on chronic hemodialysis with exhausted periferal vascular bed and only when peritoneal dialisys is'nt possible. Generally, the management of the vascular access must preview one tight collaboration between nephrologists, nurses, patient, vascular surgeons and radiologists.

Adolescent↗

[A good vascular access allows an effective treatment].

Vascular access (VA) for dialysis is defined as the 'Achilles heel', but also the 'Cinderella' of dialysis, indicating the poor consideration of the problem whether in the surgical environment, or in incomprehensible way in that nephrologic. It can only aspire to the definition 'Fundamental detail'. However, presupposed effective dialysis is a blood flow rate of 300-350 mL/min. Good VA must be easy to prepare, long lasting, free from complications, and aesthetically acceptable and economical. The arteriovenous fistula (AVF) of Cimino and Brescia, from 1966, represents the gold standard and the model of comparison for other systems, more technologically advanced. It must be programmed with an adapted margin (1-2 months) to allow maturation and access certainty for the first puncture, and never carried out sooner than 14 days from the operation. It is known from hemodynamic studies that the good functional flow of the new fistula can already regain 400-500 ml/min in the first week, with cardiological implications like the increase in cardiac throw, in ejection fraction and in the cardiac index. Health workers, patients and dialysis staff must follow a continuous educational program to protect the VA and avoid 'routine and absent-minded management', a basis for its premature failure. The nephrologist must take the responsibility upon himself not to carry out 'medical malpractice'. In the Dialysis Center of Mantova, the VA 'road map' previews all patients (young and old, affections from mono or pluropathology), first the fistula to the wrist, then the cephalic proximal. It follows the basilic vein transposition, the vascular graft to the arm or to the groin, as an alternative to peritoneal dialysis. The permanent central venous catheter (CVCp) is the last choice in patients with reduced life expectancy, heart failure, neoplastic patients with vascular patrimony destroyed by chemotherapy and ischemic lesions produced by the fistula. There were 180 afferent prevailing patients at the Mantova Dialysis Center . The natural fistula rate was 91%, grafts 7% and CVCps 2%. Between 2000 and 31 March 2004 we prepared 367 VAs. Average patient age was 65 yrs, range 20-90 yrs; 59% male and 41% female. Eighty-eight percent of operations were performed by the nephrologist (distal fistula, rescue and cephalic proximal) and 12% by the vascular surgeon (basilic vein transposition, graft in PTFE stretch to the arm and to the groin and permanent catheter in the jugular vein). The fistula with native veins was the better solution, the graft must be prepared after the exhaustion of natural possibilities, and the CVCp, for serious complications (inadequate flow and infections), must be the last alternative.

Catheterization↗

[Use of high-dose intravenous immunoglobulins in pediatric hematology].

High-dose intravenous immunoglobulin play a critical role in a lot of pediatric hematologic diseases. In our experience we studied the effects of IVIG treatment in 63 children. They all tolerated IVIG preparations in every infusions; no trouble caused the interruption of treatment. The efficacy is evident in immunomediated diseases, most of all ITP, and controlling septic episodes in immunocompromised patients (ALL, AIDS, marrow bone transplantation). An important problem is the cost of preparation; but we may consider that this treatment, for example in ITP, reduces hospitalization for children, necessity of platelets' transfusions, use of steroids and, therefore, their collateral effects. Hence, we assert that the social cost of the management of ITP disease is not higher in children treated with IVIG. Furthermore, short hospitalization for IVIG therapy contributes to accept this disease. It should be advisable to make controlled studies to define with more accuracy the role of this preparation and the modality of its use in the different clinical conditions in which it is employed.

Adolescent↗