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Biomedical subjects

S Ferretti

Publications and source records attributed to S Ferretti.

At least 37 records · Page 2Linked to original sources
PubMed2000

Optical biosensing of nitrite ions using cytochrome cd1 nitrite reductase encapsulated in a sol-gel matrix.

Nitrite is an important human health and environmental analyte. As such, the European Union (EU) has imposed a limit for nitrite in potable water of 0.1 mg l-1 (2.18 microM). In order to develop an optical biosensing system for the determination of nitrite ions in environmental waters, cytochrome cd1 nitrite reductase has been extracted and purified from the bacterium Paracoccus pantotrophus. The protein has been spectroscopically characterised in solution and important kinetic parameters of nitrite reduction of the cytochrome cd1 enzyme, i.e., Km, Vmax and kcat have been determined. The influence of pH on the activity of the cytochrome cd1 has been investigated and the results suggest that this enzyme can be used for the determination of nitrite in the pH range 6-9. Biosensing experiments with the cytochrome cd1 in solution suggested that the decrease in intensity of the absorption band associated with the d1 haem (which is the nitrite binding site), at 460 nm, with increasing nitrite concentrations would enable the measurement of this analyte with the optimum limit of detection. The cytochrome cd1 has been encapsulated in a bulk sol-gel monolith with no structural changes observed and retention of enzymatic activity. The detection of nitrite ions in the range 0.075-1.250 microM was achieved, with a limit of detection of 0.075 microM. In order to increase the speed of response, a sol-gel sandwich thin film structure was formulated with the cytochrome cd1. This structure enabled the determination of nitrite concentrations within ca. 5 min. The sol-gel sandwich entrapped cytochrome cd1 enzyme was found to be stable for several months when the films were stored at 4 degrees C.

Biosensing Techniques↗
PubMed1999

Biochemical characterization and solution structure of nitrous oxide reductase from Alcaligenes xylosoxidans (NCIMB 11015).

Nitrous oxide reductase (N2OR) is the terminal enzyme involved in denitrification by microbes. No three-dimensional structural information has been published for this enzyme. We have isolated and characterised N2OR from Alcaligenes xylosoxidans (AxN2OR) as a homodimer of M(r) 134,000 containing seven to eight copper atoms per dimer. Comparison of sequence and compositional data with other N2ORs suggests that AxN2OR is typical and can be expected to have similar domain folding and subunit structure to other members of this family of enzymes. We present synchrotron X-ray-scattering data, analysed using a model-independent method for shape restoration, which gave a approximately 20 A resolution structure of the enzyme in solution, providing a glimpse of the structure of any N2OR and shedding light on the molecular architecture of the molecule. The specific activity of AxN2OR was approximately 6 mumol of N2O reduced.min-1. (mg of protein)-1; N2OR activity showed both base and temperature activation. The visible spectrum exhibited an absorption maximum at 550 nm with a shoulder at 635 nm. On oxidation with K3Fe(CN)6, the absorption maximum shifted to 540 nm and a new shoulder at 480 nm appeared. Reduction under anaerobic conditions resulted in the formation of an inactive blue form of the enzyme with a broad absorption maximum at 650 nm. As isolated, the enzyme shows an almost featureless EPR spectrum, which changes on oxidation to give an almost completely resolved seven-line hyperfine signal in the gII region, g = 2.18, with AII = 40 G, consistent with the enzyme being partially reduced as isolated. Both the optical and EPR spectra of the oxidized enzyme are characteristic of the presence of a CuA centre.

Alcaligenes↗
PubMed1999

Histological adaptation of orthotopic ileal neobladder mucosa: 4-year follow-up of 30 patients.

OBJECTIVE: For 4 years we have monitored the histological evolution of ileal neobladders in a single cohort of 30 patients in order to systematically describe the histological changes occurring after surgery. The aim of the study was to evaluate the long-term evolution of many histological parameters with functional relevance as to the metabolic outcome of the reservoirs. METHODS: Ileal samples were collected during surgery and by random biopsies during cystoscopy 6, 12, 18, 24, 36 and 48 months later. At each step qualitative and quantitative assessment of the histological and cytological conditions of the samples was carried out. RESULTS: Morphological changes develop relatively early but the situation tends to level out in about 1 year. The morphological changes are topographically uneven and, although mucosal flattening becomes progressively prevalent, areas with shortened villi persist indefinitely. Goblet cells prevail over enterocytes and the secretive pattern shifts towards sialomucins. The overall replication rate decreases initially but tends to restore in 1 year. Dysplasia or atrophy were never recorded. CONCLUSIONS: The 4-year systematic follow-up revealed a typical histological adaptation pattern in the ileal neobladder without signs of dysplasia. The changes seem to be induced by the aggressive environment and develop in the time lag required for functional adaptation of the epithelium.

Adult↗
PubMed1999

Quantitative immunoprofiles of breast cancer performed by image analysis.

OBJECTIVE: To determine the biopathologic profiles of breast cancer for greater knowledge of tumor natural history and clinical outcome. STUDY DESIGN: In 99 in situ (ISC) and 2718 infiltrating breast carcinomas (IC), biologic markers (estrogen receptor [ER], progesterone receptor [PR] proliferation index, cerbB-2/NEU, p53, bcl-2 and DNA ploidy) were evaluated with an image analysis system (CAS 200/486). In 105 mixed invasive cancers with size < or = 1 cm, a separate analysis of in situ (ISCm) and invasive component (ICm) was obtained. A clinical study of 836 invasive breast cancers was performed. RESULTS: Different biophenotypes were obtained: among ISCs, cribriform type exhibited biologic behavior similar to that of normal breast tissue (ER+, PR+, proliferation index [PI] low, NEU-, p53-, bcl-2+) the opposite profile was displayed by comedo type, and intermediate phenotypes were observed in noncomedo and lobular types. Comparing ISC and ISCm, PI and p53 expression had the highest levels in ISCm with respect to other groups. NEU overexpression exhibited a decreasing value from ICm to IC. Younger women (< or = 40 years) with IC demonstrated a worse biologic profile (high PI, p53+, ER- and size > 2 cm). In multivariate analysis, PI and NEU in node-negative patients, and NEU, PR and size in node-positive ones emerged as prognostic parameters. CONCLUSION: The results underline the importance of the quantitative biologic profile for defining tumor behavior and patient management.

Adult↗
PubMed1998

Modulation of biomarkers in minimal breast carcinoma: a model for human breast carcinoma progression.

BACKGROUND: The widespread use of diagnostic breast imaging has yielded an increase in the detection of in situ, microinvasive, and small invasive carcinomas and has provided opportunities to study the earliest stages of breast carcinoma development. The authors of this report analyzed the pathobiologic features of 577 minimal breast carcinomas (MBCs), including in situ carcinomas and invasive carcinomas < or =1 cm, according to the definition given by Hartmann in Cancer (1984;53:681-4). METHODS: Estrogen and progesterone receptors (ER and PR), proliferation index (PI), and p53 and neu expression were studied by immunohistochemical technique and measured by quantitative image analysis in 99 pure in situ carcinomas (ISCp); in 105 mixed invasive/in situ carcinomas, with a separate analysis of in situ (ISCm) and invasive (ICm) components; and in 373 invasive carcinomas < or =1 cm (IC). Follow-up data were available for 164 invasive carcinomas. RESULTS: A progressive increase in the levels of hormone steroid receptors, from the lowest in ISCm to the highest in IC, was observed (ER, P< 0.001; PR, P=0.005). Levels of PI and p53 expression were higher in ISCm than in the other categories (PI, P=0.007; p53, P=0.046). Overexpression of neu was greater in ICm than in IC (P=0.013). Younger women (< or =40 years) with invasive carcinoma had worse biologic profiles, with lower ER (P < 0.001) and higher PI (P=0.021), neu (P=0.008), and p53 (P=0.040). It was demonstrated clinically that PI and neu were the biologic markers with the highest predictive prognostic values in univariate analysis (PI for recurrence, P < 0.015; neu for recurrence and overall survival, P < 0.001 and P < 0.007, respectively) and in multivariate analysis (neu for recurrence and overall survival, P < 0.007 and P < 0.017, respectively). CONCLUSIONS: Biologic phenotypes of MBC can be interpreted as reflecting a dimension of neoplastic progression capacity that is independent of tumor size. This study suggests that biologic markers can be integrated with traditional pathologic indicators for accurate staging of patients.

Biomarkers↗
PubMed1998

Biological profile of in situ breast cancer investigated by immunohistochemical technique.

In 74 in situ breast cancers an immunohistochemical study for estrogen (ER) and progesterone (PR) receptors, proliferation index (PI), and c-erbB-2, p53, and bcl-2 overexpression was performed. Cases were categorized as ductal carcinoma in situ (DCIS) comedo: 24.3% of cases; DCIS non comedo: 27% of cases; DCIS cribriform: 5.4% of cases; lobular carcinoma in situ (LCIS): 16.3% of cases; mixed carcinoma in situ: 27% of cases. Quantitation of immunohistochemical results was obtained with an image analysis computerized system (CAS 200). The cutoff values used were: 10% of positive area for ER, PR, NEU, and bcl-2; 5% of positive area for p53; 13% of PI for proliferative activity. DCIS cribriform and LCIS displayed a higher positivity for ER (92.6 and 93.8% of cases); DCIS cribriform and DCIS non comedo a higher for PR (89 and 75.3%); DCIS comedo presented the highest values for PI (65.4%), NEU (72.8%), and p53 expression (37.3%). All DCIS cribriform and DCIS non comedo and 99.6% of LCIS expressed bcl-2. The results underscore the importance of biological characterization of breast carcinoma in situ with the aim to define lesions natural history.

Adult↗
PubMed1998

Histomorphology of an ileal orthotopic neobladder: 24 Year's follow-up.

No morphological data are so far available about long-term (over 15 years) adaptation and outcome of ileal neobladders. In this single case report we have studied a 72-year-old man who underwent reconstruction of an ileal neobladder 24 years ago. The ileal epithelium shows changes toward a colonic aspect with villous atrophy and increased goblet cell number although, as in normal ileum, sialomucins are the most abundant secretory products. Neuroendocrine cells are reduced to a few elements of a single morphological class. Even in the presence of a low apoptotic rate reduced cell proliferation causes mucosal thinning. These adaptive mechanisms grant an excellent clinical and functional result even beyond 20 years after surgery. It is suggested that ileal neobladder can constitute an important model for the study of epithelial differentiation control.

Aged↗
PubMed1998

[The use of early enteral nutrition (EEN) after major urologic surgery].

PURPOSE: To evaluate the efficacy of early enteral nutrition in management of patients operated by major urologic surgery and to demonstrate her advantages versus total parenteral nutrition. MATERIALS AND METHODS: 20 patients, operated by radical cystectomy and urinary diversion by ureteroileocutaneostomy, Padua ileal bladder or ureterosigmoidostomy are inserted in our study: 12 were treated by early enteral nutrition for 8 days and eight by total parenteral nutrition for the same period: in each group nutritional and immunological parameters at day -1, +3 and +7, the length of postoperatory stay, the incidence of complications, with particular respect for infections have been evaluated and correlated one to each other. RESULTS: We have no death in each group; in the first group no gastroenteric allergy to the nutrient, less incidence of venous catheter and surgical wound infections (respectively p < 0.01 and p < 0.005); we have no significant decrease of postoperatory stay length; the effective problem in this group was the incidence of diarrhea, that in one case have made necessary the suspension of enteral nutrition. Enteral nutrition costs were about half of those of total parenteral nutrition. CONCLUSIONS: We believe that early enteral nutrition is an effective and safe nutrition method in patients operated by major urologic surgery: with this is possible a better nutrition, that reduce the incidence of postoperative complications, mainly infections, and maybe the length of postoperatory stay (our champion is too small for statistical evaluation), that may lead to a decrease in management costs of these patients.

Aged↗
PubMed1997

[The mini-invasive surgery of stress urinary incontinence (SUI): the use of the Vesica kit].

From February 1996 to March 1997, we have performed with the Vesica system the percutaneous bladder neck suspension in 13 pts (group 1) and the vaginal wall sling in 7 pts (group 2). After a mean follow-up of 12 months for group 1, 10 patients (76.9%) were "dry", 1 pt "improved" and 2 "failed"; in the group 2 (mean follow-up of 5 months) 6 pts/7 were "dry". Overall morbidity has been minimal. The percutaneous bladder neck suspension and the vaginal wall sling with Vesica system are minimally invasive surgical procedures for the urinary stress incontinence (hypermobility of bladder outlet and intrinsic sphincter deficiency).

Aged↗
PubMed1997

[The conservative surgery of renal carcinoma].

In the period 1986-1997, 387 cases of renal carcinoma were operated upon, at the Department of Urology, Parma General Hospital (Italy). Among these, thirty patients (all together 31 operations, 26 men and 5 women, mean age 58 +/- 11.3 years) have had conservative, nephron-sparing surgery; in 8 patients, conservative procedure was mandatory, due to previous contralateral nephrectomy or renal unreliability (4 RCC, 1 TCC, 1 severe injury, 1 pyonephrosis, 1 end stage insufficiency); in 23 patients, with normal contralateral kidney, the tumor was less than 4 cm in diameter and unique. Preoperatively, all cases had been staged by abdominal TC, chest X-ray, bone scan, renal angiography. 23 of 30 cases showed pathological stages I-II (pT1-T2), while 8 patients had stage III (pT3) tumors. After dismissal we recommended: abdominal echography after three months; again US and TC, chest X-ray after further three months. Then US and/or TC every six months, should the former results suggest a relapse, either locally and/or at a distance. Mean follow-up was 40 months. 6/30 patients (19.3%) died of metastatic disease (mean survival time: 27 months). 25 patients are alive and tumor free after a mean follow-up of 43.1 months. Immediate postoperative complications were 2 cases of urinary fistula treated by ureteral stenting.

Adult↗
PubMed1997

[Major renal trauma. Therapeutic approaches and our experience].

METHODS: During a 12-year period, 110 patients with renal blunt trauma have been observed. Renal exploration was performed in 17 patients (15.45%). Absolute indications for exploration were bleeding and pulsatile perirenal hematoma and associated abdominal injuries. Salvage was successful in 76.48% of the kidneys explored and hemostatic nephrectomy was required in 23.52%. The success rate was based on early vascular control and reconstructive techniques of renorrhaphy, partial nephrectomy and coverage with omental pedicle flaps. RESULTS: At follow-up, hypertension occurred in only 3 patients and resolved spontaneously after 3-6 months. CONCLUSIONS: On the basis of personal experience, the conclusion is drawn in that when renal exploration is required, reconstruction can be successful in a high percentage of patients.

Adolescent↗
PubMed1997

[Major complications of percutaneous nephrolithotripsy (PCNL). Analysis of our cases].

The major complications occurred in 140 cases of percutaneous nephrolithotomy, from March 1988 to December 1996 are studied. They were: 1 important hemorrhage with secondary nephrectomy, 1 intestinal fistula resolved with parenteral therapy, 1 hyponatriemic syndrome which required an intraperitoneal drainage and 1 global kidney functional exclusion after 3 months. Etiopathogenesis and suggestions for prevention are discussed as well as the necessity of adequate training.

Aged↗
PubMed1996

Biophenotypes of breast carcinoma in situ defined by image analysis of biological parameters.

In 50 in situ breast cancers an immunohistochemical study, evaluating estrogen (ER) and progesterone (PR) receptors, Proliferation Index (PI), c-erbB-2/Neu and p53 expression was performed. According to histopathological diagnosis, cases were classified as follows: 14 comedo, 8 solid, 5 micropapillary, 6 lobular, 3 papillary, 1 apocrine and 12 mixed in situ carcinomas. The quantitation of immunohistochemical results was obtained with an image analysis computerized system (CAS 200) with a lesion-field method; tumors were subdivided in fields (1177) histologically homogeneous, with 40 x microscopic objective. For ER, PR, Neu and p53, 10% of the positive area was used as cut-off value; 13% was used for PI. Cribriform and lobular types showed a higher positivity for ER (92.1% and 95.5% of the fields); cribriform and papillary a higher for PR (92.6% and 93.9%). Comedo variant demonstrated the higher PI (52.7%), Neu and p53 expression (67.7% and 43%). A cluster analysis performed on 608 fields, defined two groups according to biological homogeneous criteria. The results obtained identify the different biophenotypes of in situ carcinomas, suggesting the possibility of multiple cancerogenetic ways with a different weight of biological events.

Adult↗
PubMed1996

p53 expression in colorectal cancer: relation to tumor type, DNA ploidy pattern and short-term survival.

p53 protein expression was evaluated in a series of 204 primary colorectal adenocarcinomas by immunohistochemistry using frozen tissue sections and monoclonal antibody DO-7. Nuclear staining of more than 5% of neoplastic cells was observed in 124 (60.8%) adenocarcinomas, which were classified as p53 positive. p53 immunoreactivity was found to he unrelated to several clinical and pathologic variables, including age and sex of patient, tumor site, tumor stage, grade of differentiation, pattern of growth, degree of peritumoral lymphocytic infiltration, and venous invasion. A strong association was demonstrated between p53 immunostaining and tumor type. Only 4 of 21 mucinous carcinomas examined (19%) were p53 positive. Conversely, 120 of 183 (65.6%) nonmucinous adenocarcinomas showed positive p53 immunostaining (P <.0001). p53 expression also was related to the flow cytometric DNA ploidy pattern, aneuploid carcinomas with DI >1.20 showing higher frequency of p53 overexpression than DNA diploid, and aneuploid tumors with DI < or = 1.20 (P = .0003). No relationship was found between p53 expression and the Ki-67 proliferation index. With respect to the total study population (mean follow-up 33.4 months; range 19-47 months) the duration of overall survival was independent of p53 expression. In the group of 141 patients with stage I, stage II, and stage III disease who had undergone curative resection, positive p53 immunostaining was associated with poorer overall survival (P = .029). Subgroup analysis showed that the reduced survival conferred by p53 overexpression was confined to patients with stage III tumors (P = .027). However, in multivariate analysis, p53 expression failed to demonstrate independent prognostic significance. Our results indicate that immunohistochemical analysis of p53 expression provides valuable information for the understanding of colorectal cancer biology and clinical behavior.

Adenocarcinoma↗
PubMed1996

MIB-1 proliferative activity in invasive breast cancer measured by image analysis.

AIMS: To determine cell proliferation in infiltrating breast carcinomas. METHODS: Using the MIB-1 monoclonal antibody, the proliferation index was measured in paraffin wax sections of 871 breast cancers. The MIB-1 proliferation index was compared with other markers of disease progression: size, lymph node status, histotype, oestrogen and progesterone receptor status, expression of p53 and Neu, and DNA ploidy. All parameters were measured using image analysis. In 347 tumours, the MIB-1 and Ki-67 proliferation indexes were compared. Follow up data were available for 170 cases (median 66.5 months). RESULTS: Of the tumours, 314 (36%) had a high proliferation index. The MIB-1 proliferation index was correlated directly with size, nodal status, overexpression of p53 and Neu, and the DNA index; and inversely with oestrogen and progesterone receptor status. The correlation between MIB-1 and Ki-67 proliferation indexes was statistically significant. In patients with pT1 tumours, a low proliferation index correlated with a longer relapse-free interval and overall survival; node negative patients with a low proliferation index had a longer overall survival. CONCLUSIONS: The MIB-1 proliferation index is a reliable, practical and useful method of measuring proliferative activity and is an important predictor of clinical behaviour.

Adult↗