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Biomedical subjects

A Colombo

Publications and source records attributed to A Colombo.

At least 19 recordsLinked to original sources
PubMed2006

Optical devices used for image analysis of pigmented skin lesions: a proposal for quality assurance protocol using tissue-like phantoms.

Different technological tools have been developed to aid in the diagnosis of pigmented skin lesions, including cameras working with conventional RGB colour systems, epiluminescence microscopy and spectrophotometric methods using visible and near infrared wavelengths. All the different procedures should provide in an objective and reproducible fashion quantitative measurements of the colour and shape features of a given skin mole. At present, many devices have been introduced in experimental stages for clinical diagnosis, mainly used to provide to the clinicians an objective, computer-assisted second opinion. As for any diagnostic instruments, optical devices should also be subjected to a dedicated quality assurance protocol in order to evaluate the response repeatability of each device (intra-instrument agreement) and to check the accordance among the responses of different devices (inter-instrument agreement). The aim of this study was to design a quality assurance protocol for optical devices dedicated to image analysis of pigmented skin lesions and, in case, to detect cutaneous melanoma by using suitable tissue-like phantoms as standard references that enable testing of both hardware and software components. As an example, we report the results of intra-instrument and inter-instrument agreement when the protocol was applied on a series of 30 SpectroShade instruments, a novel optical device based on multi-spectral image analysis of colour and shape features of pigmented skin lesion.

Biophysical Phenomena↗
PubMed2006

Adjuvant chemotherapy vs radiotherapy in high-risk endometrial carcinoma: results of a randomised trial.

Patients with high-risk endometrial carcinoma (stage IcG3, IIG3 with myometrial invasion >50%, and III) receive adjuvant therapy after surgery but it is not clear whether radiotherapy (RT) or chemotherapy (CT) is better. We randomly assigned 345 patients with high-risk endometrial carcinoma to adjuvant CT (cisplatin (50 mg m(-2)), doxorubicin (45 mg m(-2)), cyclophosphamide (600 mg m(-2)) every 28 days for five cycles, or external RT (45-50 Gy on a 5 days week(-1) schedule). The primary end points were overall and progression-free survival. After a median follow-up of 95.5 months women in the CT group as compared with the RT group, had a no significant hazard ratio (HR) for death of 0.95 (95% confidence interval (CI), 0.66-1.36; P = 0.77) and a nonsignificant HR for event of 0.88 (95% CI, 0.63-1.23; P = 0.45). The 3, 5 and 7-year overall survivals were 78, 69 and 62% in the RT group and 76, 66 and 62% in the CT group. The 3, 5 and 7-year progression-free survivals were, respectively, 69, 63 and 56 and 68, 63 and 60%. Radiotherapy delayed local relapses and CT delayed metastases but these trends did not achieve statistical significance. Overall, both treatments were well tolerated. This trial failed to show any improvement in survival of patients treated with CT or the standard adjuvant radiation therapy. Randomised trials of pelvic RT combined with adjuvant cytotoxic therapy compared with RT alone are eagerly awaited.

Aged↗
PubMed2006

The ratio between arterio-venous PCO2 difference and arterio-jugular oxygen difference as estimator of critical cerebral hypoperfusion.

AIM: The aim of this study was to evaluate the arterio-venous difference in carbon dioxide tension (DPCO2) and the ratio between DPCO2 and arterio-jugular oxygen difference (AJDO2) as indicators of compensated or uncompensated cerebral hypoperfusion. METHODS: Cerebral blood flow (CBF) was reduced stepwise in 6 pigs by inducing intracranial hypertension with consequently cerebral perfusion pressure (CPP) reduction: CBF 100%, 50-60 % of baseline, 20-30% of baseline. Intracranial pressure (ICP), mean arterial pressure (MAP), CPP and CBF (laser-Doppler method) were continuously recorded. Superior sagittal sinus was punctured for the determination of AJDO2 and DPCO2. RESULTS: CBF impairment was accompanied by changes in AJDO2 from 6.03 +/- 1.21 vol% to 7.32 +/- 1.30 vol%, up to 8.07 +/- 1.32 vol% (P < 0.01), in DPCO2 from 12.17 +/- 3.25 mmHg to 16 +/- 4.12 mmHg, up to 26.5 +/- 6.41 mmHg (P < 0.01), and DPCO2/AJDO2 ratio from 2.05 +/- 0.39 to 2.06 +/- 0.72 up to 3.41 +/- 1.09 in the 3 phases (P < 0.05). CONCLUSIONS: When CBF declines AJDO2 increases, indicating greater extraction of O2 to satisfy aerobic metabolism. However, this mechanism can no longer compensate once a critical CBF threshold is reached. DPCO2 rises slowly during moderate CBF reduction because of defective washout; the rise is steeper during marked CBF impairment when anaerobic metabolism takes place. During cerebral hypoperfusion the venous blood gases and acid base variables mirror the degree of cerebral perfusion. In particular the DPCO2, and the DPCO2/ AJDO2 ratio may be useful markers of critical brain hypoperfusion.

Animals↗
PubMed2005

Human microvascular endothelial cells from different fetal organs demonstrate organ-specific CAM expression.

In this work, we isolated and produced long-term cultures of human fetal endothelial cells (fECs) deriving from different organs of the same 12-week-old embryos. Highly pure endothelium cultures were obtained from specimens of brain, heart, lung, liver, aorta and kidney by using magnetic microspheres coated with CD31 or CD34 specific endothelial antibodies. The endothelial nature of these cells was confirmed by the presence of von Willebrand Factor (vWf), Flk-1/VEGFR2 and CD31. The fECs cultures showed organ-specific differences as regards to the morphological appearance, the growth rate and the expression of cellular adhesion molecules (CAMs) before or after stimulation by the inflammatory cytokines IL-1beta and TNF-alpha. For instance, TNF-alpha showed a specific effect on fetal heart ECs by stimulating E-selectin expression. Our findings indicate that fECs may represent an innovative tool to study differences among ECs of different vascular districts of the same individual, thus increasing the possibility to compare many pathological aspects of human adult and fetal microvasculature.

Antigens, Surface↗
PubMed2005

Treatment of bifurcation lesions with two stents: one year angiographic and clinical follow up of crush versus T stenting.

OBJECTIVES: To compare long term outcomes of the crush versus the T technique in bifurcation lesions. DESIGN: 182 consecutive patients were identified who underwent percutaneous coronary interventions for bifurcation lesions with drug eluting stents between April 2002 and January 2004. Two techniques were used according to the operator's discretion: crush (group C, n = 121) or T (group T, n = 61). RESULTS: In-hospital outcome differed significantly between the two groups. Angiographic follow up was available for 142 (78%) patients. Groups C and T did not differ significantly regarding late loss (0.42 (0.39) mm v 0.34 (0.35) mm, p = 0.52) and rate of restenosis (16.2% v 13.0%, p = 0.80) in both the main and the side branch without final kissing balloon post-dilatation. However, when final kissing balloon post-dilatation was performed, group C had significantly lower late lumen loss (0.23 (0.21) mm v 0.37 (0.33) mm, p = 0.02) and restenosis rate (8.6% v 26.5%, p = 0.04) in the side branch. At one year's clinical follow up, group C compared with group T had lower rates of target lesion revascularisation (14.0% v 31.1%, p = 0.01) and target vessel revascularisation (16.5% v 32.8%, p = 0.02). CONCLUSIONS: In non-selected bifurcation lesions treated with drug eluting stents, the restenosis rate remains relatively high in the side branch. Compared with the T stenting technique, crush stenting with kissing balloon post-dilatation is associated with a reduced rate of restenosis in the side branch.

Catheterization↗
PubMed2005

TNF-alpha modulates angiopoietin-1 expression in rheumatoid synovial fibroblasts via the NF-kappa B signalling pathway.

Angiopoietin-1 (Ang-1) is one of a family of ligands for the Tie-2 receptor which has been demonstrated to be involved in angiogenesis. Little is known about the regulation of Ang-1 gene expression. We have previously demonstrated that TNF-alpha is able to up-regulate the expression of Ang-1 mRNA in synovial fibroblasts. This present study investigated the signal transduction pathways involved in the TNF-alpha induced expression of Ang-1. TNF-alpha signals primarily through the p38, JNK, MAP kinase, and IKK pathways resulting in the activation of the transcription factors AP-1 and NF-kappa B. Experiments with inhibitors and siRNA for these various signal transduction pathways revealed that TNF-alpha stimulation of Ang-1 expression occurs via the NF-kappa B signal transduction pathway.

Angiopoietin-1↗
PubMed2005

New pharmacological protocols to prevent or reduce contrast media nephropathy.

Contrast media associated acute renal failure represents the third cause of in-hospital renal function deterioration after decreased renal perfusion and post-operative renal insufficiency. Although generally benign, this complication shows a mortality rate ranging from 3.8% to 64%, depending on the increase of creatinine concentration. The mechanism by which contrast-induced renal failure occurs is not well understood. Contrast agent-associated nephrotoxicity appears to be a result of direct contrast induced renal tubular epithelial cell toxicity and renal medullary ischemia. Furthermore, a key mechanism seems to be alteration in renal dynamics, probably caused by imbalances between vasodilator and vasoconstrictor factors, including the activities of nitric oxide, prostaglandins, endothelin and reactive oxygen species. Recommendations to prevent contrast-associated nephrotoxicity are: 1) periprocedural hydration, 2) use of a low osmolality contrast, and 3) limiting the amount of contrast agent. Recently, considerable interest has resulted from the preliminary positive data on the effectiveness of prophylactic administration of antioxidant compounds (such as acetylcysteine and ascorbic acid) and fenoldopam.

Acetylcysteine↗
PubMed2005

[Treatment of stage IIIB cervical carcinoma. A comparison between radiotherapy, concurrent chemo-radiotherapy and neoadjuvant chemotherapy].

AIM: The aim of this study is to evaluate the effectiveness of radiation, concomitant chemoradiation and primary chemotherapy in the treatment of FIGO stage IIIB cervical carcinoma. METHODS: Between January 1981 and December 2001 94 women with stage IIIB FIGO cervical carcinoma were observed. Exclusive radiotherapy was administered in 30 cases (32%), radiotherapy and radiosensitizing chemotherapy in 20 cases (21%) and primary chemotherapy in 44 cases (47%); among the latter patients 2 (4%) developed neoplastic progression, 28 (64%) underwent surgery and 14 (32%) underwent radiotherapy. RESULTS: After a median follow-up of 69 months, 5-year overall survival of the 3 groups is respectively 23%, 36% and 26% (p=0.7). Total dose to point A greater than 60 Gy and the use of brachyradiotherapy are suggestive for a better outcome among women treated with radiation therapy (5-year overall survival 31% versus 18%, p=0.8 and 33% versus 23%, p=0.4, respectively). Radiologically assessed nodal status is the only statistically significant risk factor (p=0.001). Although not statistically significant, vaginal involvement is a relevant factor influencing survival (p=0.1). Women treated with concomitant chemoradiation showed a better 5-year disease-free survival (45%) when compared to the other treatment groups (radiation alone 27%, primary chemotherapy 30%, p=0.4). CONCLUSIONS: Primary chemotherapy, although useful to allow subsequent surgery, does not yield a survival advantage with respect to the irradiated patients. Among these, concomitant radiosensitizing chemotherapy is likely to improve the disease-free survival.

Adult↗
PubMed2005

Applying intravascular ultrasound to optimize the placement of coronary drug-eluting stents.

Intravascular ultrasound (IVUS) has provided in the last 2 decades major insights into the pathophysiology of coronary artery disease, and the mechanisms of action of percutaneous revascularization devices, helping the widespread adoption of coronary stents. The introduction of drug-eluting stents (DES) has recently lead to a revolution in the field of interventional cardiology, by virtually eliminating restenosis in selected low-risk lesions and significantly reducing both restenosis and repeat revascularizations in higher risk lesions. At the moment, the role of IVUS in the DES era is not well defined. Clinical studies utilizing IVUS in DES implantation used this technology mainly to evaluate the endpoint of intimal hyperplasia and to study the problem of incomplete apposition. On a theoretical basis, a method able to better evaluate optimal placement of a local drug delivery system should have a high rationale. Despite this sound preamble, no specific investigation has been conducted to evaluate the clinical need and possible advantage of routine IVUS for DES implantation and uncertainty is still present. A major hindrance lays in the low incidence of restenosis in most randomized trials enrolling few selected lesions per patient, as this fact enlarges the number of patients who need to be treated to demonstrate a benefit and casts doubts on the cost effectiveness of a more expensive and time consuming approach. The situation is bound to change when more complex patients and lesions are being treated, a setting associated with a higher event rate even when DES are used. While waiting for a prospective study addressing such issue, we can only rely on indirect evidence to justify and support the usage of IVUS in complex clinical settings with implantation of DES.

Coronary Artery Disease↗
PubMed2004

The nonpsychoactive component of marijuana cannabidiol modulates chemotaxis and IL-10 and IL-12 production of murine macrophages both in vivo and in vitro.

Cannabidiol is the main nonpsychoactive component of marijuana. We examined the ability of in vivo and in vitro cannabidiol to interfere with the production of interleukin (IL)-12 and IL-10 by murine macrophages and to modulate macrophage chemotaxis. Cannabidiol added in vitro to peritoneal macrophages significantly increased IL-12 and decreased IL-10 production. The CB1 and CB2 receptor antagonists prevented this modulation. Macrophages from animals treated with cannabidiol at the dose of 30 mg kg(-1) either orally or i.p. produced higher levels of IL-12 and lower levels of IL-10 in comparison to controls, and the CB receptor antagonists did not prevent these effects. Cannabidiol dose-dependently decreased fMLP-induced chemotaxis of macrophages, and the CB2 receptor antagonist prevented this decrease.

Adjuvants, Immunologic↗
PubMed2004

Changes in some acute phase protein and immunoglobulin concentrations in cats affected by feline infectious peritonitis or exposed to feline coronavirus infection.

The possible role of some acute phase proteins (APPs) and immunoglobulins in both the pathogenesis and diagnosis of feline infectious peritonitis (FIP) has been investigated. Serum protein electrophoresis and the concentration of haptoglobin (Hp), serum amyloid A (SAA), alpha(1)-acid glycoprotein (AGP), IgG and IgM were evaluated in cats exposed to feline coronavirus (FCoV) and in cats with FIP. The highest concentration of APPs was detected in affected cats, confirming the role of these proteins in supporting a clinical diagnosis of FIP. Repeated samplings from both FIP affected and FCoV-exposed cats showed that when FIP appeared in the group, all the cats had increased APP levels. This increase persisted only in cats that developed FIP (in spite of a decrease in alpha(2)-globulins) but it was only transient in FCoV-exposed cats, in which a long lasting increase in alpha(2)-globulins was observed. These results suggest that changes in the electrophoretic motility of APPs or APPs other than Hp, SAA and AGP might be involved in the pathogenesis of FIP or in protecting cats from the disease.

Acute-Phase Proteins↗
PubMed2004

A European multi-center trial investigating the anti-restenotic effect of intravascular sonotherapy after stenting of de novo lesions (EUROSPAH: EUROpean Sonotherapy Prevention of Arterial Hyperplasia).

BACKGROUND: Intravascular sonotherapy (IST) reduces neointimal hyperplasia post-stenting in animal studies. Euro-SPAH is a multi-center, double blind, randomized trial investigating the efficacy of IST to reduce in-stent late loss. METHODS: Patients with angina or silent ischaemia with stented de novo lesions were randomised to sham or IST. The sample size had a 90% power to detect a late loss difference of 0.21 mm at 6 months. The secondary endpoints were MACE at 1, 6, 12 months and neo-intimal hyperplasia on IVUS at 6 months. RESULTS: At 23 sites in Europe, 403 patients were randomized, with successful treatment with sham or IST in 95.6%. There were no significant differences between the groups in terms of baseline demographics or lesion characteristics. Angiographic follow-up was obtained in 89%. In-stent late loss was not significantly different. The restenosis rate at 6 months was 23% in the IST group versus 25% in the sham group. The IVUS measurements confirm the absence of effect of IST on neointimal hyperplasia. At one year, the event-free survival did not significantly differ between the two groups. CONCLUSION: The use of sonotherapy following stent implantation in de novo lesions does not reduce intra-stent neointimal hyperplasia, or effect the angiographic restenosis rate compared to sham treatment.

Aged↗
PubMed2004

Effectiveness and efficiency of intensive care medicine: variable costs in different diagnosis groups.

BACKGROUND: To establish the effectiveness of ICU treatment and the efficiency in the use of resources in patients stratified according to 10 diagnosis and two levels-of-care. To propose strategies aimed at reducing costs and improving efficiency in each patient group. METHODS: Multicentre prospective observational study. ICUs enrolled two cohorts of up to 10 consecutive patients with ICU stay >/= 48 h. Each with one of these diagnoses: trauma, brain-trauma, brain-hemorrhage, stroke, acute-on-chronic-obstructive-pulmonary disease, lung-injury/acute respiratory distress syndrome, heart failure, and scheduled/unscheduled abdominal surgery. The presence of active-life support divides high from low level-of-care treatments. Variable ICU costs were collected daily (bottom-up) for 21 days. We evaluated effectiveness (hospital survival) and efficiency (hospital-survivors variable-cost as a ratio of overall cost). RESULTS: Forty-two Italian general ICUs recruited 529 patients in 5 months. Mean ICU variable-costs significantly differed with diagnosis and level-of-care. Costs were positively affected by ICU length-of-stay, by duration of active-treatment. Outcome variably influenced costs. Medians of variable-costs per patient (1715 Euro) and patient-groups efficiencies (60.7%) identified four possible combinations between (low and high) cost and (low and high) efficiency groups. Moreover, efficiency was better than effectiveness in stroke, brain-hemorrhage and trauma, while it was worse in heart failure, acute-on-COPD or acute-lung injury. Overall ICU cost attributed only to survivors ranged from 699 (scheduled surgical) to 5906 (unscheduled surgical) Euro. Cost of non-survivors distributed to all patient was between 95 (scheduled-surgical) to 1633 (unscheduled-surgical) Euro. CONCLUSIONS: Analysis of variable patient-specific cost was used as a tool to assess intensive care performance in patient subgroups with different diagnosis and levels-of-care.

Adult↗
PubMed2004

The use of drug eluting stents in single and multivessel disease: results from a single centre experience.

OBJECTIVE: Drug eluting stents have been shown to reduce the rate of in-stent restenosis in cases where single lesions are treated. The performance of these stents, in patients with multivessel disease and complex lesions, however, remains unknown. Our experience with sirolimus eluting stents in such patients is presented. DESIGN AND PATIENTS: This study includes all consecutive patients treated at San Raffaele Hospital and EMO Centro Cuore Columbus, Milan, Italy treated with sirolimus eluting stents. RESULTS: Between April 2002 and March 2003, 486 patients with 1027 lesions were treated (437 males, 49 females) with a mean (SD) age of 62.2 (10.5) years. Of all patients studied, 19.1% had single vessel disease, 33.8% had two vessel disease, and 47.1% had three vessel disease. Of the whole study group, 20.3% of patients had diabetes mellitus. A mean (SD) of 2.3 (0.4) stents per patient and 1.1 (0.2) stents per lesion were implanted. The baseline mean reference diameter was 2.7 (0.6) mm with a mean minimal luminal diameter of 0.9 (0.5) mm. Post-stenting, the acute gain was 1.8 (0.6) mm. During hospital stay one patient died (0.2%) and 13 (2.7%) patients had in-hospital myocardial infarction (MI). One patient required urgent repeat percutaneous coronary intervention. Six months clinical follow up was performed in all 347 eligible patients. Six months mortality was 2.0% (n = 7) and acute MI occurred in 0.3% (n = 1). Target lesion revascularisation occurred in 9.5% (n = 33) of the patients and target vessel revascularisation (TVR) in 11.5% (n = 40) of the patients. Major adverse cardiac event rate was 13.8% (n = 48). TVR was 4.5% for single vessel disease and 13.2% for multivessel disease. Diabetes mellitus was the only significant predictor for TVR. CONCLUSION: The use of drug eluting stents in single and multivessel coronary disease produces good short and medium term results with a low rate of revascularisation. Longer term follow-up is required to confirm these observations.

Adult↗
PubMed2004

Microbiological evaluation of commercial probiotic products available in Italy.

Scientific evidence of the prevention and therapy of some intestinal diseases is accumulating in regard to probiotic products. However, sufficient information on the use of probiotics in specific therapies is not yet available and, above all, there is no clear legislation about these products in Europe. In this study, we evaluated five different probiotic products commercially available in Italy for their qualitative and quantitative microbial content after about 12 and 22 months of storage. We also evaluated the stability of lactobacilli to 0.3% bile salts and to pH of 3.58 and 7.98. There were discrepancies between the declared content and our results found after storage for 4 of the tested products. Bile salts and basic pH did not affect the growth of the lactobacilli tested, while for 2 tested products 6 hours at acid pH produced a complete inhibition of bacterial growth. Our results suggest the need for clear legislation and adequate control of the manufacturing of probiotic products.

Colony Count, Microbial↗