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Biomedical subjects

L Raffaele

Publications and source records attributed to L Raffaele.

33 records · Page 2Linked to original sources
PubMed1994

Incidence of seroconversion for hepatitis C virus in chronic haemodialysis patients: a prospective study.

We conducted a prospective study in HD patients of our unit to evaluate the incidence of seroconversion for HCV in this high-risk group. Two hundred and thirty-five patients were observed during the average follow-up of 29.4 months: 183 were seronegative and 52 seropositive for anti-HCV antibodies at the start of the study. During the observation period two of 183 patients developed anti-HCV antibodies late in the study, while the other 181 patients remained seronegative throughout the observation period; anti-HCV antibodies persisted through the follow-up in the 52 HCV-positive patients at the beginning of the study. Our results showed a very low incidence of HCV seropositivity (0.44% per year) after implementation of our operative protocol including 'universal precautions' and other infection control procedures. Once infected, there is no disappearance rate of anti-HCV. The 4-RIBA results did not change during the follow-up period. Prevalence of HCV RNA by PCR technique was 41% (22 of 54) among anti-HCV-positive patients. Future investigations are warranted to clarify the exact route of transmission of HCV among HD patients and to reduce the rate of HCV transmission in this clinical setting.

Adolescent↗
PubMed1993

Antibodies to hepatitis C virus (HCV) and transaminase concentration in chronic haemodialysis patients: a study with second-generation assays.

We used first- and second-generation assays such as Ortho 1, Ortho 2 and 4-RIBA to define prevalence and risk factors for anti-HCV antibodies in haemodialysed patients. Forty-nine (24%) subjects were found to be anti-HCV positive. Anti-HCV positivity was related to duration of dialysis and past or current elevations of GOT and GPT; the frequency of transfused patients was greater in HCV-positive than in HCV-negative subjects; there were 31 patients (prevalence of 20%) with anti-HCV antibodies among non-transfused patients. These findings show that, tested by second-generation assays, HCV infection is detected more than twice as commonly in haemodialysis patients and may be responsible for a significant proportion of liver disease in this clinical setting. Acquisition of hepatitis C virus by dialysis patients is not only through blood transfusions but also secondary to hepatitis C virus presence within the unit itself.

Adolescent↗
PubMed1993

Absorbed dose from contaminant electrons inside and outside megavoltage photon beams.

Megavoltage photon beams interactions with any object on their path give rise to secondary photons and electrons. This fact is particularly important in Radiotherapy. These secondary particles produce an unwanted dose contribution both on beam path and outside the geometrical edges of the irradiation field. The goal of this report is to investigate the dose contribution due to secondary electrons. Ionization measurements were made in a polystyrene phantom by means of a Markus ionization chamber, with X-ray beams produced by a "SL5" Philips and by a "Saturne 43" GE CGR linear accelerators. Specific fields for nasopharynx treatment and for supra-diaphragmatic lymphatic chains treatment ("mantle" fields) were investigated. Both depth ionization values on beam path and depth and surface ionization values outside the geometrical edges of the field were obtained. These measurements were made with and without specific electron filters for 6, 15, 25 MV X-ray beams. The results obtained prove that, both on the beam path and outside the geometrical borders of the field, electron contamination reduction by means of specific filters is important only for lower energy X-ray beams. For this sort of beams, the percentage reduction of electron contamination was found. Moreover, the amount of electron contamination outside the field geometrical edge versus field size was evaluated.

Absorption↗
PubMed1990

[Cerebral metabolism and permeability of the hemato-encephalic barrier in an experimental model for brain radiotherapy].

Whole brain irradiation (WBR) can produce acute and chronic neurological adverse effects, which are usually divided into acute, early delayed and late delayed reactions according to the time of onset. To assess the impact of WBR on brain functional parameters during the early-delayed phase, we employed the [14C]-2-deoxyglucose (2-DG) and the [14C]-alfa-aminoisobutyric (AIB) acid quantitative autoradiographic techniques to study local cerebral glucose utilization and blood-brain barrier permeability, respectively. Sprague-Dowley albino rats were exposed to conventional fractionation (200 Gy/day 5 days a week) for a total dose of 4000 Gy. Experiments were made 3 weeks after completion of the radiation exposure. In comparison with control and sham-irradiated animals, cerebral metabolic activity was diffusely decreased following irradiation. As a rule, brain areas with the highest basal metabolic rates showed the highest percentage drop in glucose utilization. Changes in blood-brain barrier function, as assessed by an increased transcapillary transport of AIB, were also demonstrated in specific brain regions. This study illustrates how moderate doses of WBR induce well-defined changes in brain metabolism and BBB function, which are possibly involved in the pathogenesis of the early-delayed radiation-induced cerebral dysfunction in humans.

Aminoisobutyric Acids↗
PubMed1988

[Optimization of the radiographic technic in parotid sialography. Experimental findings and clinical evaluation of the selection of the film-screen combination].

A suitable choice of film-screen combination is certainly the essential condition for achieving diagnostically reliable results together with the benefit of a low dosage for the patient. In parotid sialography, the choice of one particular film-screen combination depends on the different thickness of various glandular areas and on the particular anatomical site of the gland which inevitably causes the superimposition of the thinnest canalicular ducts with the adjacent areas. We have therefore performed an experimental-clinical study in order to evaluate the combination which can guarantee the most elevated diagnostic increase. The analysis of the results shows useful indication as far as the use of mammographic systems is concerned. These allow more diagnostic information together with a sufficiently low dosage for the patient.

Humans↗
PubMed1985

[Rapid identification of Enterobacteriaceae: evaluation of 3 commercial systems].

We have compared three rapid systems for the identification of Enterobacteriaceae: MS-2, Rapid 20E, Micro-ID. These methods allows to identifications of bacteria within 4-5 hours. We have chosen API 20E as reference system; because it is normally used in the clinical microbiology laboratories. We have noted good agreement of concordance for MS-2, Micro-ID and Rapid 20E towards API 20E, respectively 95, 90, 84%. We have, moreover, analysed significative difference about three systems biochemical tests in comparison with the same of API 20E.

Enterobacteriaceae↗
PubMed1981

[Triangular comparison of the agar diffusion method, the ABAC system and the Sensitre system for determination of bacterial sensitivity to aminoglycoside chemoantibiotics].

The in vitro activity of sisomicin, gentamicin, tobramycin and amikacin, four similar aminoglycosides, has been determined against 135 bacterial strains of Gram-negative bacilli representing 4 genera of common pathogens isolated from urinary tract infections. Comparison between three methods of antibiotic susceptibility tests: agar diffusion by Kirby-Bauer, semi-automatic technique using ABAC apparatus (Intertechnique, Sclavo) dilution method (MIC), has shown a considerable percentage of agreement, in almost all cases. The highest percentages of agreement have been shown for sisomicin and tobramycin. The authors analyze the role of the new techniques representing an advance in routine work.

Aminoglycosides↗
PubMedDate not supplied

[Carcinomatous neuropathy in recurrent rectal carcinoma. The results of radiotherapy and the role of CT].

More than 60% of the patients with recurrent rectal carcinoma complain of pain after radical surgery. Pelvic carcinomatous neuropathy (PCN) is a frequent cause of pain in such patients. Although the effectiveness of radiotherapy in the palliative treatment of local recurrences of rectal carcinoma is well recognized, its results in PCN are less known. The authors have evaluated the results of high-energy radiotherapy in 12 patients with recurrent rectal carcinoma and PCN, who were treated with doses between 35 and 55 Gy. Although the survival of these patients is always poor, about 50% of them achieved a significant and prolonged palliative result by radiation treatment. In patients with PCN, CT is an effective tool to detect recurrences, define their volume and relationship to critical organs, show sites of neural involvement, and optimize radiation treatment planning.

Female↗
PubMedDate not supplied

Supraclavicular lymph node metastases (SLM) from breast cancer as only site of distant disease: has radiotherapy any role?

BACKGROUND: Supraclavicular lymph node metastases (SLM) as the only site of metastatic disease from breast cancer is a rare and a poor prognostic event. In order to evaluate the role of Radiotherapy (RT) with "radical dose" to the supraclavicular fossa, we carried out a non randomized clinical trial comparing systemic therapy alone to integrated and aggressive treatment (systemic therapy plus radiotherapy). The primary end-point was time to progression (TTP). The second end-point was the overall survival (OS). METHODS: From 1/1/1989 to 31/12/1994 37 patients (with or without the presence of locoregional disease) were enrolled into two arms, of the study, but were allowed, when giving their consent, to change the arm of the study which they had been originally allotted to. Arm A, 18 patients, 15 evaluable: chemo +/- hormonotherapy for 6 courses; after the second course, if local progression disease was present, the pts. were submitted to RT and removed from the study (3 patients). Arm B, 19 patients all evaluable: chemo +/- hormonotherapy for 3 courses followed by RT with "radical" dose. Results were analyzed on 30/11/1995 and no interim analysis was performed. The potential median follow up for all patients was 56.5 months (range 11-83 months): for Arm A 61 months (range: 12-82); for Arm B 53 months (range: 11-83). The two groups were homogeneous and balanced, without statistical differences. RESULTS: Median TTP was 12.5 months in Arm A and 19.5 months in Arm B (p = 0.064). Median overall survival (OS) was 27.5 months in Arm A and 48 months in Arm B. T-status to the time of the diagnosis was found to be independent prognostic factor for TTP (p = 0.0029). Disease-free interval from diagnosis to recurrence was found to be a significant prognostic factor for OS (p = 0.009). CONCLUSION: The results in Arm B demonstrated the opportunity of a long term control in this subset of patients. Therefore we suggest the start of a wider multicenter study in order to define the biological significance of SLM, its importance in staging breast cancer and to consider the optimum treatment.

Adult↗