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Biomedical subjects

A Piffanelli

Publications and source records attributed to A Piffanelli.

At least 37 records · Page 2Linked to original sources
PubMed1998

Cerebral hypoperfusion detected by SPET in early neuro-Behçet syndrome.

We used brain single-photon emission tomography (SPET) to detect hypoperfused areas in 15 consecutive Behçet syndrome patients. Five were suspected of having neuro-Behçet syndrome, having at least one neurological symptom. For these patients, SPET was performed within 1 month of the onset of nervous system involvement. The 15 patients fulfilled the criteria of the International Study Group for Behçet syndrome. Neurological assessment and SPET were complemented by EEG in all five patients with suspected neuro-Behçet syndrome and by magnetic resonance imaging in three. Brain SPET detected hypoperfused regions in all five neurological patients; EEG showed abnormalities in three. Magnetic resonance imaging was normal in the three patients in whom it was performed. SPET was negative in all patients without neurological involvement and 20 healthy controls. SPET detected a reduction in brain blood flow in early neuro-Behçet syndrome, but there was no definitive correlation between the hypoperfused brain regions and the clinical features. Further studies are required to evaluate the significance of brain hypoperfusion and the value of SPET in the early diagnosis of neuro-Behçet syndrome.

Adult↗
PubMed1997

Technetium-99m sestamibi leg scintigraphy for non-invasive assessment of propionyl-L-carnitine induced changes in skeletal muscle metabolism.

Carnitine derivatives, such as propionyl-l-carnitine (PLC), have been shown to improve walking distance in patients with obstructive peripheral artery disease (PAOD). The aim of this study was to ascertain whether technetium-99m sestamibi leg scintigraphy may be a useful tool in the evaluation of changes in skeletal muscle metabolism induced by chronic therapy with PLC. Twenty patients with clinical and instrumental evidence of PAOD were randomly assigned to a 3-month period of therapy with either PLC or placebo. Rest 99mTc-sestamibi leg scintigraphy and echo-Doppler sonography were performed on all subjects immediately before and upon completion of the treatment period. At the end of the protocol the following results were observed in patients who underwent PLC administration: (a) a significant increase in both thigh and calf 99mTc-sestamibi uptake, in comparison with baseline values (P<0.001); (b) the absence of statistically significant modifications of Doppler blood flow indices of the lower limbs. In conclusion, after chronic administration of PLC, a significant increment in skeletal muscle uptake of 99mTc-sestamibi was demonstrated without any apparent change in regional blood flow. This fact, if proven in further studies, may suggest a role for this tracer as a non-invasive probe of tissue bioenergetics.

Arterial Occlusive Diseases↗
PubMed1997

Prognostic significance of ras/p21 alterations in human ovarian cancer.

Ras/p21 oncoprotein expression and K-ras mutations were analysed by Western blot and/or K-ras oligonucleotide hybridization in 78 primary ovarian cancers, 20 omental metastases, two low malignant potential tumours (LMP), nine benign ovarian tumours and 10 normal ovaries. A cut-off value of an integral of absorbance (i.a.) of 2.20, obtained by receiver operating characteristic (ROC) curve, was shown to be the best cut-off for defining p21 positivity. p21 levels were higher in malignant tumours than in benign tumours (median 2.10 i.a. vs median 1.22 i.a.; P = 0.014) and in omental metastases than in primary ovarian carcinomas (median 2.54 i.a. vs median 2.1 i.a.; P = 0.0089). p21 overexpression did not correlate with any of the clinicopathological parameters examined. Follow-up data were available for 63 patients. A significant relationship was shown between p21 positivity and a shorter overall survival (OS) (P < 0.03) and progression-free survival (PFS) (P < 0.03). In multivariate analysis only the presence of ascites, p21 levels and epidermal growth factor receptor status retained an independent prognostic role. K-ras gene mutations were frequently detected in benign and low malignant potential tumours (71.4%), which were mostly mucinous (P = 0.0152).

Animals↗
PubMed1997

Brain perfusion SPET and proton magnetic resonance spectroscopy in the evaluation of two systemic lupus erythematosus patients with mild neuropsychiatric manifestations.

The diagnosis of central nervous system (CNS) involvement appears to be a major problem in systemic lupus erythematosus (SLE), especially when the clinical signs are non-specific or neuroimaging is unremarkable. Two SLE patients with mild neuropsychiatric manifestations were studied with magnetic resonance imaging (MRI), single photon emission tomography (SPET) and localized proton magnetic resonance spectroscopy (H-1 MRS). MRI was normal in both patients. SPET revealed areas of hypoperfusion in both patients. H-1 MRS demonstrated metabolic abnormalities in the regions corresponding to the hypoperfused areas. A correlation between H-1 MRS and SPET was noted: patients with mild neuropsychiatric SLE may have disturbances evident on SPET and H-1 MRS in the presence of normal anatomy on MRI, suggesting that CNS involvement in SLE has very strong physiological and neurometabolic components in individual patients.

Adult↗
PubMed1996

Determination of ErbB2 protein in breast cancer tissues by different methods. Relationships with other biological parameters.

Four different methods to measure in parallel the erbB2 protein expression (p185neu) were evaluated in order to: a) compare two enzyme immunoassays with the immunohistochemical assays (IHC) and western blotting (WB) and b) extrapolate eventual relationships between erbB2 and biological parameters. Tissue samples from 248 patients with primary breast cancer were consecutively assayed. We used two different cut-off levels for WB, ELISA, and EIA, defined as follows: 1) the highest level of expression of non malignant tissue was chosen as the discriminant threshold between 'low' and 'elevated' samples: 2) the elevated group was further subdivided into two subgroups: 'intermediate' and 'high', according to their median value. According to the first cut-off, the results were considered 'elevated' in about 52% of cases with the three biochemical methods, while using the second cut-off the percentage lowered to about 26%. Considering this cut-off, the concordance rates between the paired biochemical methods ranged between: 78.4% (WB vs EIA), 93% (ELISA vs EIA), and 82.6% (ELISA vs WB). The comparison between biochemical and immunohistochemical methods gave these concordance rates: 82% (WB vs IHC), 90.5% (ELISA vs IHC), and 85.5% (EIA vs. IHC). According to the first cut off level, 27.5% of tumor samples showed IHC detectable p185 levels, in agreement with other immunohistochemical studies. The relationship between high erbB2 and estrogen and progesterone receptors showed an inverse association. No relationship was found between erbB2 and axillary lymph node positivity or tumor size. In short, the results of the four methods seem generally well correlated; nevertheless, it appears that different methodological approaches of measuring p185neu are not completely equivalent, and there is a need for an authoritative standardization and quality control for clinical applications.

Blotting, Western↗
PubMed1996

[Scintigraphy with radiogallium in oncologic and non-oncologic diseases. State of the art and main indications].

Gallium-67 citrate (67Ga) can be considered one of the most widespread viability radiotracers. Several papers have recently been published on the use of 67Ga in different diseases, with emphasis on its value in the management of lymphoma patients. This paper critically discusses the role of gallium scintigraphy in several diseases on the basis of our personal experience and of the latest literature data, to integrate the diagnostic knowledge of radiologists, oncologists, nuclear medicine and laboratory physicians. From a clinical point of view, the best application is in neoplastic diseases, particularly lymphoma, but also in inflammatory conditions. Gallium scan sensitivity is very high (80-90%) in the staging and follow-up of Hodgkin's and non-Hodgkin's lymphoma and this method is also of great importance during the follow-up of lymphoma patients. We recommend scintigraphy to study the residual mediastinal mass after treatment. The recent experience of the National Cancer Institute (Milan) in the follow-up of 189 lymphoma patient showed the major role of gallium scan, compared with MRI, in the study of the mediastinal region after treatment. Both sensitivity and specificity were very high (90 and 96.9% vs 88.7 and 89.2% respectively). Gallium scintigraphy can also be used to study the disease-free interval, post-treatment survival, the early signs of a recurrence and also of treatment response times. The comparison of the survival curves of 33 diffuse large cell non-Hodgkin's lymphoma patients, examined at the National Cancer Institute, showed a statistically significant difference (log-rank test: p = 0.0125) between patients with positive and negative gallium scan after 4-6 cycles of chemotherapy. As for inflammatory diseases, gallium scintigraphy can play a major diagnostic role in pulmonary conditions, e.g., sarcoidosis, in AIDS-related respiratory diseases, in pneumoconiosis and in some cases of "fever of unknown origin". The contribution of this technique consists in localizing an infection focus and assessing the inflammatory disease activity, thus permitting a better therapeutic approach.

Citrates↗
PubMed1995

Brain single-photon emission tomography with 99mTc-HMPAO in neuropsychiatric systemic lupus erythematosus: relations with EEG and MRI findings and clinical manifestations.

Central nervous system (CNS) involvement in patients with systemic lupus erythematosus (SLE) is often difficult to evaluate because of protean neuropsychiatric (NP) manifestations and lack of reliable diagnostic markers. In the reported study the role of single-photon emission tomography (SPET) with technetium-99m hexamethylpropylene amine oxime (HMPAO) in the evaluation of CNS involvement in SLE was assessed and the relations between SPET perfusion defects, EEG examination, magnetic resonance imaging (MRI) findings and clinical presentation were examined. Twenty SLE patients with different NP manifestations were studied. Multiple areas of hypoperfusion, especially in the territory of the middle cerebral artery, were demonstrated by SPET analysis in all 20 patients. The number of hypoperfused areas and the degree of hypoperfusion, expressed by an asymmetry index (AI), were more marked in patients with multiple NP manifestations. MRI and EEG evaluations were positive for 14 of 18 and for 12 of 20 patients, respectively. In the patients with positive SPET and MRI, 87 MRI focal lesions and 63 hypoperfused areas were found, and for 51 of these 63 at least one MRI lesion was found in the same anatomical region. SPET examination of patients with a normal EEG showed fewer hypoperfused areas and a lower degree of asymmetry compared to patients with an abnormal EEG. SPET of patients with focal EEG abnormalities showed more hypoperfused areas (difference not statistically significant) and a higher AI than did SPET of the patients with diffuse EEG abnormalities. Seven of 11 anatomical regions with focal EEG abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Subcellular distribution of technetium-99m-N-NOEt in rat myocardium.

UNLABELLED: The aim of this study was to determine the subcellular distribution of bis(N-ethoxy N-ethyl)dithiocarbamato nitrido technetium(V) (99mTcN-NOEt) in rat heart by differential centrifugation techniques. Extraction of the activity from homogenized rat heart tissue was also performed to assess whether myocardial retention might induce changes in the chemical identity of the complex. METHODS: Anesthetized rats were intravenously injected with 99mTcN-NOEt, the heart tissue was extracted and homogenized and tissue fractions were obtained by differential centrifugation. The efficiency of organelle separation was determined by assay of each centrifugal fraction using enzyme markers. Lactate dehydrogenase (LDH), acid phosphatase (ACP), alkaline phosphatase (ALP) and 5'-nucleotidase (5'ND) activities were assayed using standard spectrophotometric methods. Succinic dehydrogenase (SDH) activity was determined using a p-iodo-nitrotetrazolium-linked assay. Severe cell membrane and organelle disruption were induced by prolonging the homogenization time and their effect on the subcellular distribution of 99mTcN-NOEt was studied. The activity from homogenized heart tissue was extracted using the Folch technique and analyzed by TLC and HPLC. RESULTS: Most of the 99mTcN-NOEt activity was found to be associated with the hydrophobic components of the cell. No evidence of specific association of activity with the cytosolic and mitochondrial components was observed. Organelle and membrane cleavage did not cause release of activity into the cytosol. Approximately 90% of 99mTcN-NOEt activity was extracted from ventricular tissue and the chemical nature of 99mTcN-NOEt was not altered by uptake by myocardium. CONCLUSION: Cell membranes are the most apparent site of localization of 99mTcN-NOEt in heart tissue.

Animals↗
PubMed1995

[The role of muscle scintigraphy with 201Tl in the morphofunctional assessment of obliterative arterial pathology of the lower limbs].

This study was aimed at assessing the role of stress 201Tl leg scintigraphy, compared with digital angiography, in the diagnosis and prognosis of peripheral arterial obstructive disease (PAOD) before and after surgical treatment. Fifty-four patients with known PAOD in Fontaine stages IIb, III or IV submitted to revascularization (36) or lumbar ganglionectomy (18), were examined with both angiography and scintigraphy. A statistical analysis of 360 segments (thighs and calves) was performed; in particular, correlation values were derived from 216 preoperative and 144 postoperative segments (18 patients who underwent lumbar ganglionectomy were not submitted to postoperative angiography). Scintigraphy vs. angiography sensitivity (84%), specificity (80%) and diagnostic accuracy (90%) values obtained in this study are in agreement with those reported in international literature. Scintigraphy yields information on the locoregional perfusion of an angiography-demonstrated anatomic lesion, under physiologic stress, which is particularly useful in symptomatic patients with angiographically unimportant stenoses. At present, 201Tl leg scintigraphy is the only technique yielding semiquantitative data in the assessment of single muscle groups perfusion increase in Fontaine IV patients submitted to lumbar ganglionectomy. The original contribution of this study consists in the evidence of a high predictive value (p < 0.01) of scintigraphy in the calculation of pain-free intervals in the patients with successful revascularization at clinics and angiography. This finding, if confirmed, shows a possible role for 201Tl leg scintigraphy in the diagnosis of peripheral arterial obstructive disease.

Aged↗
PubMed1995

[Significance and usefulness of SPECT with Tc-99m HMPAO in the diagnosis of hemicrania with aura].

It is generally agreed upon that the attacks of migraine with aura are indicative of abnormal cerebral perfusion, while the permanence of such perfusion abnormalities during the pain-free intervals of migraine remains debated. This study was aimed at assessing: 1) the presence of cerebral perfusion abnormalities also during the interictal phase and 2) the role of SPET with 99mTc HM-PAO to diagnose migraine. Twenty-eight patients (22 women and 6 men), diagnosed as having migraine with aura according to the International Headache Society (Headache Classification Committee criteria), were submitted to SPET studies, within 10 days of the last attack. 99mTc HM-PAO was used as perfusion tracer and a single head rotating gamma camera equipped with a high-resolution collimator was used for data acquisition. The qualitative analysis of SPET images showed slight hypoperfusion areas in 22 of 28 patients (79%). In 12 of 22 patients (55%) a regional correlation was observed between hypoperfusion areas and the neurologic symptoms of aura. The results of the present study are in agreement with the current physiopathologic interpretation of migraine with aura, confirming the instability of cerebral perfusion control, even with instrumental evidence of perfusion abnormalities in the interictal period. Moreover, SPET with 99mTc Hm-PAO seems to be a useful tool in the diagnostic assessment of migraine.

Adolescent↗
PubMed1995

Immunoradiometric versus enzymatic renin assay: results of the Italian Multicenter Comparative Study. Italian Multicenter Study for Standardization of Renin Measurement.

OBJECTIVES: The measurement of plasma renin activity (PRA) is very convenient for estimating the action of the renin system, but its interlaboratory reproducibility is notoriously poor. This multicentre study aimed to examine whether an immunoradiometric assay which quantifies renin directly with monoclonal antibodies can reduce this limitation of the enzymatic assay. The study also aimed to establish the reference values of immunoreactive renin (IrR) in a large sample of normotensive subjects and patients with various pathophysiological conditions. DESIGN AND METHODS: PRA and IrR were measured once in each of the eight participant centres in eight pool plasma samples with a wide range of renin content; in seven centres these measurements were repeated twice more in order to compare the intralaboratory interassay reproducibility of both methods. Finally, PRA and IrR were measured in the supine and standing positions in 503 subjects including normal controls, patients with various forms of hypertension, patients with Cushing's and Bartter's syndromes, patients with hepatic cirrhosis and pregnant women. RESULTS: We found that both the inter- and intralaboratory coefficients of variation for PRA measurements were higher than those for IrR. In plasma samples from normal subjects and from patients, mean +/- SEM supine PRA and IrR ranged, respectively, from 0.08 +/- 0.03 ng/ml per h and 2.6 +/- 0.5 pg/ml in patients with Conn's syndrome to 7.2 +/- 2.5 ng/ml per h and 138 +/- 51 pg/ml in patients with hepatic cirrhosis. PRA and IrR were found to be significantly correlated in all laboratories (mean +/- SEM of correlation coefficients 0.84 +/- 0.03) and for all of the conditions (correlation coefficient ranging from 0.98 in patients with Cushing's syndrome to 0.50 in pregnant women). However, for the pregnant women the slope of the regression line depicting the PRA-IrR relationship was significantly steeper than for all of the other conditions. CONCLUSIONS: In our experience the inter- and intralaboratory reproducibilities of the immunoradiometric assay appear to be greater than can be achieved with the enzymatic assay, the difference being probably due to the greater complexity of the latter. The two methods provide superimposable information on the renin-angiotensin system activity, except in pregnancy, during which the PRA:IrR ratio is much higher than in the other conditions. Therefore, in this and other pathophysiological situations associated with marked angiotensinogen concentration alterations, the enzymatic assay may be still preferable for assessing the activity of the system accurately.

Adolescent↗
PubMed1995

Myocardial perfusion imaging with technetium-99m-Tc NOET: comparison with thallium-201 and coronary angiography.

UNLABELLED: We compared TcN-NOET [bis(N-ethoxy, N-ethyl dithiocarbamato)nitrido 99mTc] and 201Tl images to estimate the utility of this compound in the detection of coronary artery disease (CAD). METHODS: Twenty-five patients undergoing cardiac catheterization had stress-redistribution-reinjection 201Tl SPECT imaging, stress-delayed (2, 4 and 6 hr postinjection) and rest-delayed (4 hr postinjection) TcN-NOET SPECT imaging. RESULTS: Nineteen patients had coronary stenosis > or = 50% and six were normal. Stress TcN-NOET and 201Tl imaging were concordant for the presence of CAD in 22/25 patients (88%, kappa = 0.76 +/- 0.20). The overall sensitivity of TcN-NOET SPECT imaging was 74% (14/19 patients) and 68% (13/19 patients) for 201Tl SPECT imaging. The specificity was 100% (6/6 patients) for both techniques. The overall agreement of TcN-NOET and 201Tl for the presence of disease in individual coronary arteries was 96% (72/75 arteries, kappa = 0.92 +/- 0.16). Segmental analysis of stress images showed a concordance in 211/225 segments (94%, kappa = 0.82 +/- 0.09). Comparison of the 4-hr images showed a concordance between 201Tl and TcN-NOET in 21/23 patients. Following TcN-NOET injection at rest, seven patients had a defect on the initial images, which had normalized 4 hr postinjection in four patients (57%). CONCLUSION: Perfusion imaging with TcN-NOET and 201Tl gives comparable diagnostic information in patients undergoing exercise testing for assessment of CAD. Because of the normalization of myocardial activity 4 hr after injection in some patients, we conclude that TcN-NOET is a potential technetium compound equivalent to 201Tl.

Adult↗
PubMed1994

Expression of ras oncogene p21 protein in normal and neoplastic laryngeal tissues: correlation with histopathological features and epidermal growth factor receptors.

Western blotting analysis of the p21 ras oncoprotein was performed in seven normal laryngeal mucosa specimens and 43 primary laryngeal cancers. Varying p21 levels, expressed as optical density (OD), were found in normal mucosa (median 1.94 OD, range 0.90-2.17 OD) and in primary laryngeal tumours (median 1.74 OD, range 0.30-6.37 OD). When p21 expression in laryngeal cancer was compared with the normal counterpart, higher levels were found in neoplastic than in normal laryngeal tissue (median 2.54 OD, range 1.76-6.37 OD, vs median 1.94 OD, range 0.90-2.17 OD) (P = 0.023). Immunohistochemical analysis demonstrated that most of the tumour cells (more than 70%) were immunostained while the stromal component was unreactive. No correlation between p21 expression and tumour location, stage and histopathological grade was observed. The correlation between ras p21 protein expression and epidermal growth factor receptor (EGFR) levels was also investigated. EGFR-positive cases did not show any difference in p21 expression with respect to EGFR-negative cases (median 1.52 OD, range 0.30-6.37 OD, vs median 1.84 OD, range 0.93-3.71 OD). Our findings suggest that overexpression of p21 protein is associated with a malignant phenotype in laryngeal cancer. Further studies should be undertaken to evaluate whether the assessment of p21 protein expression may have clinical significance in laryngeal cancer.

Adult↗
PubMed1994

Quality assessment of tumor marker determinations: a proposal for a supraregional scheme.

The use of tumor marker tests has increased progressively in the last decade concomitant with the advent of new monoclonal antibodies and their growing use in clinical oncology for various follow-up programs. External quality assessment (EQA) schemes widely adopted in clinical chemistry, have been extended in the last decade to immunoassays of hormones and tumor markers. EQA results can provide realistic information on the quality of the assays, performed under routine conditions. The goal of this article is to report the main results and discrepancies encountered so far in External Quality Assessment programs on tumor markers.

Analysis of Variance↗
PubMed1994

Sister chromatid exchanges in cultured amniocytes exposed to diagnostic ultrasound in vitro.

An in vitro system has been set up to study the possible genetic effects of diagnostic ultrasound (US) on the developing fetus. Amniotic cells were cultured by the in situ technique. Well established clones were exposed to US for various lengths of time using a linear array transducer within a sound transparent apparatus. Cells were then grown in the presence of 5-bromo-2'-deoxyuridine and processed for scoring the number of sister chromatid exchanges (SCE) as the cytogenetic endpoint. There was no linear relationship between the SCE frequency and the duration of US exposure. Variance analysis showed that only interindividual variability was a significant component of total variation. Neither the main effect of treatment nor the interaction effect were statistically significant. The data suggest that US delivered from a diagnostic unit to actively growing cultured fetal cells in a system closely mimicking the conditions of US exposure during amniocentesis does not induce SCE.

Adult↗
PubMed1993

Expression of ras p21 oncoprotein in normal and neoplastic human endometrium.

The ras-encoded p21 protein expression was investigated in 18 normal endometrial tissues and in 37 human primary endometrial carcinomas by Western blotting analysis. Scattered p21 levels were found in normal specimens (mean = 1.29 OD; median = 1.10 OD; range = 0.33-2.65). The p21 levels were significantly higher in secretory (mean = 1.99 OD; median = 2.16 OD; range = 0.71-2.65) than in proliferative (mean = 0.97 OD; median = 1.07 OD; range 0.38-1.73) endometrium (P = 0.009) and higher in primary endometrial carcinomas (mean = 2.05 OD; median = 2.04 OD; range 0.21-4.36) than in normal proliferative tissues (P = 0.004). Immunohistochemical analysis showed that most of the tumor cells expressed p21 oncoprotein while the stromal component was unreactive. No correlation between p21 expression and histopathological characteristics of the tumors was observed. Moreover, estrogen receptor (ER)-positive tumors expressed higher p21 levels than did ER-negative tumors (77% vs 33%; P = 0.009). A similar trend, although not statistically significant, was found between p21 values and progesterone receptor expression (74% vs 44%; P = 0.060). On the other side, p21 levels were unrelated to epidermal growth factor receptor levels. Further studies should verify the possible significance of p21 expression in the prognostic characterization of patients with endometrial cancer.

Adult↗
PubMed1993

Expression of ras oncogene p21 protein in normal and neoplastic ovarian tissues: correlation with histopathologic features and receptors for estrogen, progesterone, and epidermal growth factor.

OBJECTIVE: The aim of the study was to investigate the biologic significance of p21 expression in normal and neoplastic ovarian tissues. STUDY DESIGN: Western blotting analysis of p21/ras oncoprotein was conducted in a group of 14 normal and cystic ovaries, six benign tumors, 42 primary ovarian cancers, and 15 omental metastases. RESULTS: Levels of p21 were similar in normal and cystic ovaries and in benign tumors, whereas they were significantly higher in malignant tumors than in control tissues (median 1.91, range 0.12 to 5.00 vs median 1.03, range 0.32 to 2.20; p = 0.023) and in omental metastases than in primary ovarian carcinomas (median 3.05, range 0.55 to 5.72 vs median 1.97, range 0.12 to 5.00; p = 0.14). We found no correlation between p21 expression and histopathologic or clinical characteristics. Estrogen receptor-positive and progesterone receptor-positive tumors expressed higher p21 levels than did estrogen receptor-negative and progesterone receptor-negative tumors (p < 0.05), but no correlation with epidermal growth factor receptor status was found. In the univariate analysis of survival p21 positivity showed a negative prognostic value. CONCLUSION: The enhancement of p21 protein is associated in the ovarian tissue with the malignant phenotype and the acquisition of metastatic potential.

Adult↗