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Biomedical subjects

D Giorgi

Publications and source records attributed to D Giorgi.

At least 73 records · Page 4Linked to original sources
PubMed1997

Increased myocardial echo density in left ventricular pressure and volume overload in human aortic valvular disease: an ultrasonic tissue characterization study.

Quantitatively assessed ultrasonic backscatter is an index of ultrasonic tissue characterization directly related to morphometrically evaluated collagen in human beings. Our objective was to assess myocardial reflectivity pattern of patients with severe left ventricular hypertrophy caused by either aortic stenosis (AS) or aortic regurgitation (AR). Ten patients with AS, 10 patients with AR, and 10 closely age- and gender-matched healthy controls were studied by two-dimensional Doppler echocardiography. By using an echocardiographic prototype, we performed a radiofrequency analysis to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and the posterior wall (integrated backscatter index: IBI, expressed in percentage). All patients with stenosis or aortic insufficiency showed a normal regional and global resting systolic function (fractional shortening: AS = 36.0 +/- 6.6 versus AR = 40.3 +/- 6.2 versus control = 40.2 +/- 8.7; p = not significant [NS]) Left ventricular mass index (Devereux's formula) was markedly increased in patients with stenosis or aortic insufficiency (AS = 199.3 +/- 18 versus AR = 208.8 +/- 60 versus control = 97.3 +/- 11 g/m2; p < 0.0001). Myocardial echo density was increased in patients with stenosis or aortic insufficiency in comparison with controls, both in the septum (IBI%: AR = 40.7 +/- 7.9 versus AS = 33.4 +/- 4.2 versus control = 23.0 +/- 6.2; p < 0.0001) and in the posterior wall (IBI%: AR = 27.1 +/- 4.3 versus AS = 23.0 +/- 2.6 versus control = 15.0 +/- 4.2; p < 0.0001). No significant correlations were found between septal and posterior wall IBI and their thickness. Abnormally increased myocardial echo density--possibly related to disproportionate collagen deposition--can be detected in patients with pressure or volume overload caused by aortic valve disease and without overt systolic dysfunction.

Aged↗
PubMed1997

Risk of breast cancer subsequent to histological or clinical diagnosis of fibroadenoma--retrospective longitudinal study of 3938 cases.

BACKGROUND: The widespread belief that fibroadenoma is associated with an increased risk of subsequent breast cancer is based on studies of histologically-confirmed fibroadenomas. In current practice only a minority of fibroadenomas are excised; most of them are diagnosed on the basis of palpation and imaging, and are not surgically removed. The decision for surgical excision may be influenced by the presence of individual risk factors, and this can act as a confounder and bias studies that are based only on surgically excised fibroadenomas. PATIENTS AND METHODS: To investigate this hypothesis we linked data from a consecutive series of 3938 fibroadenomas diagnosed histologically (n = 1335) or clinically (n = 2603) in women aged 30 to 69 years to the Tuscany Cancer Registry database. After exclusion of concurrent breast cancers or cancers occurring within six months after the diagnosis of fibroadenoma, the observed and expected incidence of subsequent breast cancer were compared. RESULTS: The overall Standardized Incidence Ratio (SIR) for excised and non-excised fibroadenomas was 1.38 (95% CI = 1.1-1.7). The SIR for histologically-confirmed fibroadenomas was 2.0 (95% CI 1.4-2.7) whereas there was no apparent risk for non-excised fibroadenomas (SIR = 0.97, 95% CI = 0.7-1.4). CONCLUSION: This study suggests that assessment of breast cancer risk subsequent to a diagnosis of fibroadenoma may be biased if the analysis is limited to surgically-excised fibroadenomas.

Adult↗
PubMed1997

Ultrasonic videodensitometric analysis of two different models of left ventricular hypertrophy. Athlete's heart and hypertension.

Absolute or relative increases in intramyocardial fibrosis accompany hypertrophy development in human hypertension. Myocardial texture analysis of two-dimensional echocardiographic gray-level distribution has been shown to identify alterations attributed to abnormal collagen content in several conditions. Therefore, this echocardiographic tool might help to identify those hypertensive individuals with abnormal interstitial collagen deposition, a condition that may promote and/or aggravate morbidity in this group of people who are at high risk for cardiovascular events. We compared male essential hypertensive subjects who had marked cardiac hypertrophy (left ventricular mass index adjusted for height > 2 SD of mean of control group) (group 1) with normotensive elite veteran athletes who had comparable cardiac hypertrophy (group 2) and sedentary normotensive subjects as controls (group 3). The groups (n = 14 each) were matched for age (+/- 2 years) and sex. We analyzed echocardiographic digitized data quantitatively by means of a calibrated 256 gray level digitization system to calculate midseptal and midposterior end-diastolic and end-systolic mean gray levels and to derive the so-called cyclic variation index, ie, the percent mean gray level variation during the cardiac cycle. Echocardiographic parietal and septal thicknesses and masses were evaluated according to the Penn convention. Left ventricular mass index (adjusted for height) overlapped between groups 1 and 2 (187.1 +/- 17.5 and 181.3 +/- 19.3 g/m, respectively; P = NS), whereas it was obviously smaller in control subjects (93.1 +/- 18.6 g/m; P < .001 for both). According to inclusion criteria, both septal and posterior wall thicknesses were comparable in athletes and hypertensive subjects, and they were higher than in the control group (P < .0001). The hypertensive subjects showed a significantly lower cyclic variation index than the control and athlete groups for both the septum (P < .001) and posterior wall (P < .001); no statistical difference was found between athletes and control subjects for this parameter. In conclusion, abnormalities of two-dimensional echocardiographic gray-level distribution are present in hypertensive hypertrophied individuals but seem unrelated to the degree of echocardiographic hypertrophy as such. An altered collagen network distribution or a decrease in capillary distribution in severe myocardial hypertrophy, secondary to pressure-volume overload in hypertension with other yet unknown mechanisms, could help to explain our findings. Further work is needed to establish the prognostic, clinical, and therapeutic implications of these findings.

Analysis of Variance↗
PubMed1997

Ischemic optic neuritis in Churg-Strauss syndrome.

There are few reports of neuro-ophthalmologic involvement in Churg-Strauss syndrome (CSs). We described a case of unilateral optic atrophy in a 46-year-old-white man with CSs. The patient had severe bronchial asthma, allergic rhinitis, hypereosinophilia (8%) and peripheral neuropathy. The visual acuity in his right eye was light perception. At the biomicroscopy there were no corneal and conjunctival lesions. Ophthalmoscopy showed a pale right optic disc and fluorangiography revealed a marked hypofluorescence of the disc at early phase of angiogram. We suggested that the optic atrophy was most probably due to vasculitis of the ciliary arteries.

Atrophy↗
PubMed1997

[Nonsteroidal anti-inflammatory agents: their topical use in the treatment of xerophthalmia secondary to Sjögren's syndrome].

The authors, in a case-control study, analyzed the topical application of nonsteroidal anti-inflammatory drug (flurbiprofene drops) in patients affected by keratoconjunctivitis sicca in Sjögren's syndrome. The variation of break-up-time values, and xerophthalmia grade were analyzed. A mild increase of mean values of break-up-time (two seconds in the treated group), and a mild decrease of xerophthalmia grade were found.

Administration, Topical↗
PubMed1996

Simultaneous dobutamine stress echocardiography and dobutamine scintigraphy (99mTc-MIBI-SPET) for assessment of coronary artery disease.

BACKGROUND: Simultaneous dobutamine stress echocardiography (DSE) and 99Tc-MIBI-SPET (DMS) for the evaluation of the presence and the extent of coronary artery disease (CAD) were assessed for a head to head comparison regarding the diagnostic acuracy of the two rests. METHODS AND RESULTS: Forty-five consecutive patients (33 males and 12 females: 53 +/- 6.8 yr.) underwent exercise electrocardiography and simultaneous dobutamine stress echocardiography and MIBI-SPET imaging. Coronary angiography was performed in all patients (significant coronary stenosis > 50%). On the basis of the results of exercise electrocardiogram the pre-test probability for coronary artery disease (Diamond's algorithm) was low (45.6 +/- 12.7%). The overall specificity, sensitivity and predictive accuracy of Echo-dobutamine stress test for diagnosis of the presence or absence of CAD were: specificity 82%, sensitivity 76%, diagnostic accuracy 80%, positive predictive value 90%, negative predictive value 40%. The overall specificity, sensitivity and predictive accuracy of MIBI-SPET-dobutamine test for diagnosis of the presence or absence of CAD were: specificity 86%, sensitivity 87%, diagnostic accuracy 84%, positive predictive value 97%, negative predictive value 54%. MIBI-SPET-dobutamine test showed a significantly higher sensitivity in comparison with ECHO-dobutamine test (P < 0.05). CONCLUSION: Both noninvasive methods for the detection of CAD showed a good diagnostic accuracy. Nevertheless the SPET model showed a higher sensitivity in comparison with DSE model, essentially in the presence of a lower extent of CAD and during submaximal test.

Cardiotonic Agents↗
PubMed1996

Left ventricular function during exercise in athletes and in sedentary men.

Aim of this study was to evaluate left ventricular function during exercise in 10 male elite runners and in 10 sedentary males. End-diastolic (EDV) and end-systolic volume (ESV), left ventricular ejection fraction (EF), early peak transmitral flow velocity (peak E), time-velocity integral of mitral inflow (m-TVI); mitral cross sectional area (m-CSA); mitral stroke volume (SV), and cardiac output (CO) were measured by echo-Doppler. We simultaneously analyzed: VO2max by spirometric method, mean arterial blood pressure (MAP) by sphygmomanometer, and heart rate (HR) by ECG. The parameters were measured under basal conditions (level 1), at 50% of maximal aerobic capacity (level 2), at peak of exercise (level 3) and during recovery. Ejection fraction in athletes increased significantly at peak of exercise through Frank-Starling mechanism. Stroke volume and cardiac output increased significantly in athletes at peak of exercise. Left ventricular diastolic function was superior in athletes versus controls: in fact, higher peak E in athletes enhanced early diastolic ventricular filling. Therefore, the athletes showed complex cardiovascular adjustments induced by training, which allowed an higher peak working power, a greater cardiac output, and VO2max when compared with an untrained control population.

Adult↗
PubMed1996

Ultrasonic videodensitometric analysis in type 1 diabetic myocardium.

OBJECTIVE: To test the hypothesis that quantitative analysis of two-dimensional echocardiographic gray-level distributions could allow one to detect the early changes in acoustic properties of human diabetes myocardium differentiating it from normal myocardium. METHODS: We evaluated, by two-dimensional echocardiography, 28 asymptomatic type 1 insulin-dependent diabetic patients with normal ventricular function (group A) and 15 age- and sex-matched healthy controls (group B). By selection, all of the diabetics were normotensive and had a negative maximal exercise stress. Echocardiographic images were digitized by using a calibrated digitization system. Quantitative texture analysis was accomplished on data from the septum and posterior wall both at end-diastole and at end-systole. The following parameters were obtained: the mean gray level of the regions of interest, and its absolute SD, skewness, kurtosis, and cyclic variation index. RESULTS: The main result of this study was that the cyclic variation indices of the echo amplitudes of the septum and posterior wall in the diabetic group were significantly lower than those in controls (P < 0.001 and P < 0.002, respectively). Furthermore, the diabetic group had a significantly higher mean gray level of the septum [group A 54.3 +/- 22.5 (mean +/- SD) versus group B 39.7 +/- 9.8, P < 0.03] at end-diastole. The mean gray-level of the posterior wall was similar in the two groups, both at end-diastole and at end-systole. CONCLUSION: Alterations of cyclic echo amplitude (possibly related to collagen deposition) can be detected in asymptomatic diabetic patients with normal resting function. Theoretically, this finding might be considered an early preclinical alteration, potentially related to subsequent development of "diabetic cardiomyopathy'.

Adult↗
PubMed1996

A complex satellite DNA polymorphism flanking the human ryanodine receptor gene (RYR1).

We describe a new highly polymorphic DNA marker flanking the human ryanodine receptor gene (RYR1) at chromosome band 19q13.1. The marker is composed of a 25bp minisatellite sequence, a compound microsatellite (AC)(AT), and an oligo-T stretch. STS mapping of previously published markers from 19q13.1 helped to integrate the genetic and physical maps of this region. Together with D19S422, the new polymorphism forms a pair of markers closely flanking either side of the RYR1 gene which may be useful for linkage studies in families susceptible to malignant hyperthermia and central core disease.

Base Sequence↗
PubMed1995

Direct selection of cDNAs using whole chromosomes.

We have developed a method for direct selection of cDNAs using whole chromosomes as target DNA. Double-strand cDNAs were synthesized from human fetal brain polyadenylated mRNAs. Flow-sorted chromosomes 17 and 19 were amplified by degenerate oligonucleotide primed polymerase chain reaction (DOP-PCR) and used to capture ds cDNAs by an improved magnetic bead capture protocol. To demonstrate the capabilities of this method, the selected cDNAs were used as probes in FISH experiments. The selected cDNA populations specifically painted chromosomes 17 or 19 on metaphase spreads. These results demonstrate that it is possible to do chromosome painting using cDNA probes and that this method is a means to rapidly select expressed sequences encoded by any portion of the genome.

Brain↗
PubMed1995

Molecular cloning of a human genomic region containing the H blood group alpha(1,2)fucosyltransferase gene and two H locus-related DNA restriction fragments. Isolation of a candidate for the human Secretor blood group locus.

We have used the human H blood group alpha(1,2)fucosyltransferase (FUT1) cDNA to screen chromosome 19 cosmid libraries in a search for the human Secretor (Se) blood group gene (FUT2). One cosmid has been isolated that contains two distinct segments that cross-hybridize with FUT1. We have assembled a 100-kilobase (kb) cosmid contig, localized to 19q13.3, encompassing FUT1 and the two FUT1-related sequences, termed Sec1 and Sec2, for Secretor candidate 1 and 2. Sec1 and Sec2 are separated by 12 kb and are 65.5 kb and 35 kb apart, respectively, from the FUT1 gene. We used a cosmid-dependent direct cDNA selection method to clone a cDNA corresponding to a transcript that emanates from Sec2. This cDNA detects a 3.35-kb transcript in human tissues known to express the Se locus. Together with sequence and expression data reported in the accompanying article (Kelly, R. J., Rouquier, S., Giorgi, D., Lennon, G. G., and Lowe, J. B. (1995) J. Biol. Chem. 270, 4640-4649), these data demonstrate that Sec2 corresponds to the human Se blood group locus (FUT2). Our results furthermore define the physical relationship between the H and Se loci and confirm a hypothesis that these two loci represent distinct but closely linked alpha(1,2)fucosyltransferase genes.

Animals↗
PubMed1995

Sequence and expression of a candidate for the human Secretor blood group alpha(1,2)fucosyltransferase gene (FUT2). Homozygosity for an enzyme-inactivating nonsense mutation commonly correlates with the non-secretor phenotype.

Synthesis of soluble A, B, H, and Lewis b blood group antigens in humans is determined by the Secretor (Se) (FUT2) blood group locus. Genetic, biochemical, and molecular analyses indicate that this locus corresponds to an alpha(1,2)fucosyltransferase gene distinct from the genetically-linked H blood group alpha(1,2)fucosyltransferase locus. The accompanying paper (Rouquier, S., Lowe, J. B., Kelly, R. J., Fertitta, A. L., Lennon, G. G., and Giorgi, D. (1995) J. Biol. Chem. 270, 4632-4639) describes the molecular cloning and mapping of two human DNA segments that are physically linked to, and cross-hybridize with, the H locus. We present here an analysis of these two new DNA segments. One of these, termed Sec1, is a pseudogene, because translational frameshifts and termination codons interrupt potential open reading frames that would otherwise share primary sequence similarity with the H alpha(1,2)fucosyltransferase. The other DNA segment, termed Sec2, predicts a 332-amino acid-long polypeptide, and a longer isoform, that share 68% sequence identity with the COOH-terminal 292 residues of the human H blood group alpha(1,2)fucosyltransferase. Sec2 encodes an alpha(1,2)fucosyltransferase with catalytic properties that mirror those ascribed to the Secretor locus-encoded alpha(1,2)fucosyltransferase. Approximately 20% of randomly-selected individuals were found to be apparently homozygous for an enzyme-inactivating nonsense allele (Trp143-->ter) at this locus, in correspondence to the frequency of the non-secretor phenotype in most human populations. Furthermore, each of six unrelated non-secretor individuals are also apparently homozygous for this null allele. These results indicate that Sec2 corresponds to the human Secretor blood group locus (FUT2) and indicate that homozygosity for a common nonsense allele is responsible for the nonsecretor phenotype in many non-secretor individuals.

Alleles↗
PubMed1995

A model-based prediction of the impact on reduction in mortality by a breast cancer screening programme in the city of Florence, Italy.

The efficacy of breast cancer screening for women older than 50 years has been shown in several studies. Service screening is now ongoing or planned in several countries in Europe. MISCAN, a computer simulation programme, has been used to analyse data from the Florence District Programme (FDP) breast cancer experience. First, the model was fitted to the screening results for the period 1975-1986. A good correspondence between the model outcomes and the FDP results was achieved. It was then used to predict the impact on mortality of the new starting programme of the city of Florence (63,000 women, 50-69 years old). Assuming a 70% attendance rate, then for the city of Florence, 2563 screen-detected breast cancers are predicted for the period 1991-2020 out of the total number of 9095 breast cancers for all ages (28%). A total of 3720 deaths for breast cancer are expected without screening. An absolute reduction of 472 deaths (13%) is predicted for the whole population. The estimated number of years of life gained by screening until 2020 is 4354. Simulation by MISCAN has previously been a useful support tool for decision-making about screening. The present paper is the first based on a southern European experience. The possibility of applying MISCAN to predict the impact of a national programme in Italy is discussed.

Adult↗
PubMed1995

Evaluation of maximal left ventricular performance in elite bicyclists.

Aim of this work was to study in a group of elite cyclists, undergoing laboratory testing, the trend of the left ventricular systolic and diastolic function, echocardiographically and Doppler derived, simultaneously with the evaluation of ergospirometric parameters during maximal exercise. We studied a group of male subjects, consisting of 10 professional elite bicyclists (mean age: 25.1 +/- 3.2 years) during competitive activity (VO2/kg max: 78.5 +/- 7.7 ml.kg.min-1). The maximal exercise test, conducted with Wind Loaded Simulator for optimisation of ergometric capacity, showed, at the end of exercise, at a speed of 49.2 +/- 2.4 km/h, a VO2max of 5365 +/- 543.4 ml/min, with a calculated Cardiac Output (CO) of 19.3 +/- 3.7 l/min. A linear regression relationship was found between VO2max and CO (r = 0.84; p < 0.0001) as well as between VO2max and maximal reached speed (r = 0.97; p < 0.0001). During the aerobic period a slight but significant increase in End Diastolic Volume (EDV) was observed due to the greater venous return from exercising muscles. At stop, in anaerobic period, the EDV remained substantially constant. Ejection Fraction (EF) also increased during exercise through the Frank-Starling mechanism activation. The slight, but not significant, increase in EF at stop level may be explained by an activation of homeometric control of contractility with a sympathetic modulation on myocardial fibres. The early diastolic mitral flow velocity (Peak E) increased significantly during exercise, in comparison with basal upright values. The left ventricular diastolic compliance observed in athletes permits a good left ventricular filling, particularly in early diastolic phase; this allows an excellent left ventricular systolic performance. Based on echocardiography and pulsed Doppler measurements, calculated cardiac output is underestimated by approximately 20%.

Adult↗
PubMed1995

Accuracy and reliability of frozen section diagnosis in a series of 672 nonpalpable breast lesions.

Frozen section (FS) diagnosis was routinely performed in a large series of nonpalpable breast lesions from 1977 through 1991. The original FS diagnoses of 672 patients were classified in four categories (1 = benign lesion, 2 = in situ carcinoma, 3 = invasive carcinoma, 4 = deferred diagnosis) and compared with the diagnoses obtained at review of the permanent paraffin sections to estimate the accuracy of FS. A review of the mammographic pattern of the lesion was also performed. Frozen section diagnostic conclusion was deferred to permanent paraffin sections in only 22 cases (3.3%). Benign or malignant (grouping in situ and invasive carcinomas) FS diagnoses were accurate in 623 of 650 cases (95.8%). Overall, the prevalence of malignant lesions was 44.8% with a benign/malignant ratio of 1.2. The diagnosis was modified on the basis of permanent sections in 27 cases (4.2%) with three false positives and 24 false negatives. Sensitivity and specificity of FS diagnoses were 91.7 and 99.2%, respectively. When the comparison between FS and histologic diagnoses was analyzed according to the mammographic pattern, sensitivity among patients with microcalcifications as the only alteration was lower (88.8%) than among patients with opacities (94.9%). On the basis of these results, FS is to be considered a feasible and reliable diagnostic procedure in nonpalpable breast lesions, particularly in cases excised because of a mammographic opacity that is identifiable on gross examination of the surgical specimen.

Breast Neoplasms↗
PubMed1995

The influence of age on the flash visual evoked potentials.

The effect of age on flash visual evoked potentials was investigate in 148 normal subjects aged 6 yo 84 years. The occurrence of the P1 wave progressively increased with age, while the P2 wave was recordable in all the subjects. There were significant effects of age on the P2 latency (p < or = 0.01). The latency of the N1 and N2 waves significantly changed with age. In particular, the N2 wave that occurred in the absence of the P1 wave had a latency similar to that of the N1 wave was present. We suggest that the cases apparently without the P1 wave could be explained with a merging of this was with the P2 wave in a major single deflection.

Adolescent↗