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Biomedical subjects

A Bonifacino

Publications and source records attributed to A Bonifacino.

17 recordsLinked to original sources
PubMed2003

[New and old procedures in the diagnosis of dubious breast lesions].

In the last years the detection of early breast cancers (lesions less than one centimetre in diameter, with good prognosis) has consistently increased for the wide application of mammary screening programs. At the same time, an increasing number of radiographically detected unexpected lesions (nonpalpable breast lesions) has been evidenced. In those cases, often both mammography and ultrasound evaluation are dubious and a multidisciplinary diagnostic approach is mandatory. Fine-needle aspiration (FNA) and core biopsy (CB) are well established diagnostic methods but, in recent years, new microinvasive bioptic procedures (as the Mammotome and the ABBI systems) have been introduced. In this review the limits and the possibilities of the classical and new cytohistological techniques are evaluated. A possible multistep diagnostic approach is described on a cost-benefit basis and in consideration of the various procedures.

Biopsy, Needle↗
PubMed2001

Lentivirus vector-mediated hematopoietic stem cell gene transfer of common gamma-chain cytokine receptor in rhesus macaques.

Nonhuman primate model systems of autologous CD34+ cell transplant are the most effective means to assess the safety and capabilities of lentivirus vectors. Toward this end, we tested the efficiency of marking, gene expression, and transplant of bone marrow and peripheral blood CD34+ cells using a self-inactivating lentivirus vector (CS-Rh-MLV-E) bearing an internal murine leukemia virus long terminal repeat derived from a murine retrovirus adapted to replicate in rhesus macaques. In vitro cytokine stimulation was not required to achieve efficient transduction of CD34+ cells resulting in marking and gene expression of the reporter gene encoding enhanced green fluorescent protein (EGFP) following transplant of the CD34+ cells. Monkeys transplanted with mobilized peripheral blood CD34+ cells resulted in EGFP expression in 1 to 10% of multilineage peripheral blood cells, including red blood cells and platelets, stable for 15 months to date. The relative level of gene expression utilizing this vector is 2- to 10-fold greater than that utilizing a non-self-inactivating lentivirus vector bearing the cytomegalovirus immediate-early promoter. In contrast, in animals transplanted with autologous bone marrow CD34+ cells, multilineage EGFP expression was evident initially but diminished over time. We further tested our lentivirus vector system by demonstrating gene transfer of the human common gamma-chain cytokine receptor gene (gamma(c)), deficient in X-linked SCID patients and recently successfully used to treat disease. Marking was 0.42 and.001 HIV-1 vector DNA copy per 100 cells in two animals. To date, all EGFP- and gamma(c)-transplanted animals are healthy. This system may prove useful for expression of therapeutic genes in human hematopoietic cells.

Animals↗
PubMed2000

Cytotoxicity of liquid disinfectants.

This study was prompted by toxic responses to disinfecting agents reported in patients after surgical procedures and in sensitized health care personnel. We evaluated the cytotoxicity of seven substances used in the formulation of common liquid chemical disinfectants and sterilants. We found that a standard method based on direct microscopic examination of cell cultures was insensitive and may result in an underestimation of the risk that disinfectants pose to health care personnel or patients who are exposed to these substances. Using independent quantitative tests measuring the integrity of the cellular membrane, metabolic activity, or cell growth, we found that there is a several-hundredfold difference in the relative toxicity of various disinfecting substances. The concentration toxic in 50% of the cell population (TC(50)) that was found for each disinfectant was similar in a variety of cell lines from human, monkey, or mouse origin. Statistical analysis of TC(50)s suggests that liquid disinfecting agents could be classified in three main groups according to their relative toxicity, with: (1) mild (TC(50) > 1 mM, including phenol, hydrogen peroxide, and formaldehyde); (2) moderate (1mM > TC(50) > 0.1 mM, sodium hypochlorite); and (3) severe (TC(50) < 0.1 mM, glutaraldehyde, cupric ascorbate, and peracetic acid) toxicity. These data suggest a vast difference in the potential risk of various disinfectants and sterilants. The data presented in this study should help to define the relative toxic risk of different disinfecting substances to patients and health care personnel and assist in the selection of safer microbicidal formulations.

Animals↗
PubMed1999

Bacterial spores survive treatment with commercial sterilants and disinfectants.

This study compared the activity of commercial liquid sterilants and disinfectants on Bacillus subtilis spores deposited on three types of devices made of noncorrodible, corrodible, or polymeric material. Products like Renalin, Exspor, Wavicide-01, Cidexplus, and cupric ascorbate were tested under conditions specified for liquid sterilization. These products, at the shorter times indicated for disinfection, and popular disinfectants, like Clorox, Cavicide, and Lysol were also studied. Data obtained with a sensitive and quantitative test suggest that commercial liquid sterilants and disinfectants are less effective on contaminated surfaces than generally acknowledged.

Bacillus subtilis↗
PubMed1996

Comparative sporicidal effect of liquid chemical germicides on three medical devices contaminated with spores of Bacillus subtilis.

BACKGROUND: The relatively limited variety of surfaces and geometries challenged in current sporicidal testing reduces the predictive value of these analyses when extrapolated to the wide variety of medical devices. The unknown spore load being challenged and the qualitative nature (growth/no growth) of those tests further prevent precise comparison among liquid chemical disinfectants. Hence, the relative activity of different chemical substances has not been clearly established, hindering selection of the best agent for each clinical situation. METHODS: A micromethod was developed to assess sporicidal activity against Bacillus subtilis spores deposited on three different medical devices; carbon steel dental burs, silicone-rubber medical catheters, and titanium-alloy dental abutment screws. The spore load on each device and the recovery after three analytical steps were quantitatively assessed with spores radiolabeled with carbon 14 methionine. RESULTS: The killing of 2 to 7 x 10(6) spores loaded on three different devices and exposed to glutaraldehyde, formaldehyde, copper ascorbate, hydrogen peroxide, peracetic acid, sodium hypochlorite, or phenol for 30 minutes at 20 degrees C ranged from a 10(3)-fold decrease for 10% hydrogen peroxide to zero decrease for 5% phenol. Our results suggest that the nature of the surface being challenged may affect the sporicidal activity of some chemical agents. CONCLUSION: The quantitative data presented allow comparison of the sporicidal effect of different liquid chemical agents. These findings may help prevent an overestimation of sporicidal activity and possible transmission of pathogens from the surface of improperly decontaminated medical devices.

Bacillus subtilis↗
PubMed1996

Comparative sporicidal effects of liquid chemical agents.

We compared the effectiveness of glutaraldehyde, formaldehyde, hydrogen peroxide, peracetic acid, cupric ascorbate (plus a sublethal amount of hydrogen peroxide), sodium hypochlorite, and phenol to inactivate Bacillus subtilis spores under various conditions. Each chemical agent was distinctly affected by pH, storage time after activation, dilution, and temperature. Only three of the preparations (hypochlorite, peracetic acid, and cupric ascorbate) studied here inactivated more than 99.9% of the spore load after a 30-min incubation at 20 degrees C at concentrations generally used to decontaminate medical devices. Under similar conditions, glutaraldehyde inactivated approximately 90%, and hydrogen peroxide, formaldehyde, and phenol produced little killing of spores in suspension. By kinetic analysis at different temperatures, we calculated the rate of spore inactivation (k) and the activation energy of spore killing (delta E) for each chemical agent. Rates of spore inactivation had a similar delta E value of approximately 20 kcal/mol (ca.83.68 kJ/mol) for every substance tested. The variation among k values allowed a quantitative comparison of liquid germicidal agents.

Ascorbic Acid↗
PubMed1994

Treatment of autonomous thyroid nodules with percutaneous ethanol injection: 4-year experience.

PURPOSE: To evaluate the long-term efficacy of treatment of autonomous thyroid nodules with percutaneous ethanol injection under ultrasound guidance. MATERIALS AND METHODS: Treatment was performed in 101 patients. The mean ratio of injected ethanol volume to nodule volume was approximately 1.5; ethanol was usually administered in four to eight sessions. RESULTS: Complete cure was achieved in 59 patients. Partial cure was achieved in 34 patients. Eight patients had remission of thyrotoxicosis but persistence of thyroid-stimulating hormone level suppression and radionuclide uptake only in the nodule. The extent of the response was inversely proportional to the nodule volume. Marked nodule shrinkage was observed in all groups. No recurrences were observed. Transient vocal cord paresis occurred in four patients, with full recovery in all cases. CONCLUSION: This method compares favorably with both surgery and radioiodine treatment, especially when the very low prevalence of posttreatment hypothyroidism is considered.

Adolescent↗
PubMed1993

[Role of color Doppler in the evaluation of the hyperfunctioning thyroid nodule treated with ethanol injection].

Color Doppler gives us the possibility to study autonomous thyroid nodules and their qualitative and morphological aspects and allows us to hit session by session the most vascular area of the nodule with alcohol (Percutaneous ethanol injection). The use of color gives an easier flowmeter analysis reducing its time of performance. Today this method with the latest up to date echographs can provide very good clinical pathology at relatively low costs. We studied 18 patients, with autonomous thyroid nodules. They were all treated by percutaneous echo-guided ethanol injection (PEI). Before the beginning we make sure that the rest of the thyroid gland may function normally. The color Doppler test was carried out by using the multidisciplinary ecotomograph AU 560 CFM supplied with a linear probe 7.5 mHz, AL 35 by Esaote Biomedica. Before the PEI treatment, with the eco color Doppler test we noticed that the hot nodules clearly presented a higher vascularization compared to the remaining parenchyma. The vascularization was more evident in the peripheral area of the nodule even if few signs of flow were present inside the nodule. During a 24 months followup, 10 patients showed an important reduction and sometimes even the extinction of the intranodular flow signs followed by a clear reduction of the nodule's volume.

Ethanol↗
PubMed1987

Abdominal hydatid disease: US findings during medical treatment.

The sonographic appearance of 141 hepatic and abdominal hydatid cysts was studied in 63 patients undergoing therapy with benzoimidazolic compounds. The cysts were evaluated for size, margins of the cyst wall, and echo pattern of cyst contents to establish the response to the drugs. Changes seen on ultrasound (US) scans were classified as decrease in size, detachment of the cyst membrane, and appearance of echogenic material (matrix) in the cyst cavity. These findings, particularly the diffusely hyperechoic pattern, are explained on the basis of the action of the drugs. Twenty-one patients underwent surgery at the end of treatment. The US patterns of treated hydatid cysts are similar to those seen, though more rarely, in cases of spontaneous parasite involution in long-standing hydatidosis.

Abdomen↗
PubMed1983

Intraoperative high-resolution hepatosonography in the detection of occult metastases in colorectal carcinoma.

During surgery of colorectal cancer, real time B-mode high resolution ultrasound scanning was employed intraoperatively in 25 consecutive patients free of metastases at preoperative evaluation, to localize hepatic deposits. Results showed that intraoperative ultrasonography is a safe and simple technique providing the surgeon with accurate informations which may affect surgical technique as for -) extended indications for hepatic resection -) reduction of resections oncologically useless -) a more correct staging of resected colorectal cancer -) reduction of false positives at second look guided by CEA elevation.

Colonic Neoplasms↗
PubMed1983

Intraoperative high-resolution ultrasonography in the localization of occult endocrine pancreatic tumours.

Intraoperative pancraticosonography was employed in six patients to localize suspected endocrine tumours and to study the specific ultrasonic features. The cases included four insulinomas, one case of occult G-cell apudoma and one case of beta-cell microadenomatosis. Endocrine tumours are generally hypoechoeic and well defined with smooth borders. The study confirms that real-time operative high resolution sonography is a reliable technique to assist in the diagnosis of occult endocrine tumours and to guide the surgical approach.

Adenoma↗
PubMedDate not supplied

[Interventional echography in senology].

The echographic investigation in senology represents a complement to the mammography in the early diagnosis of carcinoma, above all when it is still expressed through radiological indirect signs (glandular distortion and microcalcifications) in absence of a nodule. The echographic examination must be done with probes suitable to the superficial tissue: 7.5-10 MHz color and power Doppler. This examination has a greater significance in the identification of the benign lesions, in the control of the operated breast and in the guide of the interventional manoeuvres (FNAB, mammotome, core biopsy, preoperative localization of not palpable nodules).

Biopsy, Needle↗
PubMedDate not supplied

Topographic diagnosis and surgical treatment of insulinoma.

AIM: Controversy continues to reign with regard to the need for preoperative localization of insulinomas and to which are the most sensitive and accurate diagnostic imaging modalities. Our aim was to determine the role of diagnostic procedures and suggest which of them are really useful. METHODS: Over a 12-year period 34 patients underwent several preoperative diagnostic procedures to localize the insulinoma: ultrasonography (US) in 20 cases, computed tomography (CT) in 26, magnetic resonance imaging (MRI) in 28, selective angiography in 8, arterial stimulation venous sampling (ASVS) in 23 and Octreoscan in 26. All patients underwent surgical palpation and in 32 cases intraoperative ultrasonography (IOUS) was performed. Twenty-six cases underwent enucleation, six had distal pancreatic resections and two patients had only exploratory laparotomy with liver biopsies. We compared the findings of the diagnostic procedures and analyzed the surgical treatment chosen according to the pancreatic site of the tumor. RESULTS: In 32 (94.1%) of the 34 patients with clinically suspected pancreatic insulinoma the tumor was found at surgery. Preoperative US achieved 5.2% sensitivity, CT 29.1%, selective angiography 28.5% and MRI 76.9%. ASVS achieved 91.3% sensitivity and diagnostic accuracy whereas Octreoscan achieved only 65.3% diagnostic accuracy. Surgical palpation performed before IOUS identified the tumors in 30/34 patients: in the other four cases, one was a false-positive result (a cyst in the pancreatic head), two were true negatives and one was a false negative. Surgical palpation therefore yielded 88.2% diagnostic accuracy. IOUS was performed in 32 cases and localized the tumors in 29/32 cases (sensitivity: 96.6%) with one false-negative result (diagnostic accuracy: 96.8%). The operative mortality was 2.9% and the morbidity 24.6% (30.7% in patients treated by tumor enucleation). CONCLUSIONS: No single diagnostic imaging modality is reliable for localizing insulinoma. We therefore suggest combined MRI, ASVS and IOUS. ASVS provides particularly useful information for planning manual palpation and intraoperative ultrasonography.

Adolescent↗
PubMedDate not supplied

Resistance of Pseudomonas aeruginosa to liquid disinfectants on contaminated surfaces before formation of biofilms.

A comparison was made of the effectiveness of popular disinfectants (Cavicide, Cidexplus, Clorox, Exspor, Lysol, Renalin, and Wavicide) under conditions prescribed for disinfection in the respective product labels on Pseudomonas aeruginosa either in suspension or deposited onto surfaces of metallic or polymeric plastic devices. The testing also included 7 nonformulated germicidal agents (glutaraldehyde, formaldehyde, peracetic acid, hydrogen peroxide, sodium hypochlorite, phenol, and cupric ascorbate) commonly used in disinfection and decontamination. Results showed that P. aeruginosa is on average 300-fold more resistant when present on contaminated surfaces than in suspension. This increase in resistance agrees with results reported in studies of biofilms, but unexpectedly, it precedes biofilm formation. The surface to which bacteria are attached can influence the effectiveness of disinfectants. Viable bacteria attached to devices may require dislodging through more than a one-step method for detection. The data, obtained with a sensitive and quantitative test, suggest that disinfectants are less effective on contaminated surfaces than generally acknowledged.

Biofilms↗
PubMedDate not supplied

Effects of salt and serum on the sporicidal activity of liquid disinfectants.

This study compares the effects of various concentrations of salt or serum in the killing of Bacillus subtilis spores by either glutaraldehyde, sodium hypochlorite, cupric ascorbate, hydrogen peroxide, peracetic acid, formaldehyde, or phenol. Salt affected only glutaraldehyde, its sporicidal activity increasing with an increase in concentration of sodium bicarbonate or sodium chloride. The sporicidal activity of glutaraldehyde was minimal when the concentrations of aldehyde groups and lysine residues from protein were similar. We present an equation describing the effect of serum on spore survival as a function of glutaraldehyde concentration that fits the data with a regression coefficient of 0.9. Cupric ascorbate and peracetic acid were inhibited by serum, but this effect was linked to a rise in pH. Sodium hypochlorite was the agent most sensitive to protein, with its sporicidal activity nearly disappearing in the presence of 2% serum or an equivalent amount of purified protein.

Bacillus subtilis↗