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Biomedical subjects

G Mancini

Publications and source records attributed to G Mancini.

At least 37 records · Page 2Linked to original sources
PubMed1995

High-quality compression of echographic images by neural networks and vector quantisation.

A compression method is presented for medical images based on neural networks and vector quantisation (VQ). The neural net is a perceptron and it is followed by some expressly designed VQ algorithms. The method devotes special attention to the quality of the reconstructed images and to the reduction of artefacts. The compression ratio obtained in the long run with echographic images is greater than 50:1 with good quality.

Algorithms↗
PubMed1995

Spontaneous middle cerebral artery reperfusion in ischemic stroke. A follow-up study with transcranial Doppler.

BACKGROUND AND PURPOSE: The aim of this study was to investigate by means of transcranial Doppler (TCD) ultrasonography how many spontaneous reperfusions of the middle cerebral artery (MCA) occurred during the first week after onset of acute ischemic stroke in the carotid territory. METHODS: TCD examination, computed tomographic scan, and arterial digital angiography were performed in 56 patients with acute ischemic stroke within 6 hours of the onset of symptoms. The TCD examination was repeated within 24 hours, 48 hours, and 7 days after stroke; a further TCD examination was performed within 3 to 9 months in 27 patients. RESULTS: At 6 hours, 33 patients presented abnormal TCD findings in the symptomatic MCA (16 "no flows" and 17 asymmetries). Of these, 4 patients (3 no flows and 1 asymmetry) died before the 7-day follow-up was completed, whereas of the 29 remaining patients undergoing all the TCD control examinations, only 14 presented permanently abnormal TCD findings (7 asymmetries and 7 no flows). These data are consistent with an MCA reperfusion occurring at any level of the MCA, although most frequently in the distal part, and in the majority of cases during the first 48 hours. One patient who showed MCA asymmetrical flow velocity at the day-7 TCD examination was normal at the TCD follow-up at 3 to 9 months. CONCLUSIONS: TCD examination offers an easy and reliable way of monitoring MCA reopening and might be useful to identify subgroups of patients who may benefit most from pharmacological reperfusion.

Acute Disease↗
PubMed1995

[Colon volvulus].

The authors report a clinical case and review the international literature. After an analysis of the incidence and the predisposing factors causing this disorder, they focus attention on the question of therapy. In forms with vital loop non-surgical derotation must be attempted. In the event of the failure of non-invasive treatment and to prevent recidivation these forms are treated surgically, also using videolaparoscopy. In forms with non-vital loop, surgery consists of the section of the necrotic segment and preparation of anastomosis which may be immediate or deferred depending on general and local conditions.

Adult↗
PubMed1994

Ataxia, mental deterioration, epilepsy in a family with dominant enamel hypoplasia: a variant of Kohlschütter-Tönz syndrome?

We describe 3 sibs, their father, and paternal grandfather with amelogenesis imperfecta. In 2 sibs and the father the defect is associated with a neurological syndrome which has a wide range of phenotypic variability. The proposita has ataxia, EEG abnormalities, moderate dementia, and enamel hypoplasia. This case and the affected relatives are discussed in relation to Kohlschütter-Tönz syndrome and neuroectodermal diseases. The syndrome described here, characterized by the association of a genetic enamel defect and neurological impairment, may be of considerable interest in advancing genetic and clinical knowledge on ectodermal tissues and their development.

Abnormalities, Multiple↗
PubMed1994

Maternal serum markers. Estimation of the risk of Down's syndrome: a prospective study.

The risk of Down's syndrome pregnancies can be estimated by quantitation of maternal serum markers, namely alpha-fetoprotein, unconjugated estriol and human chorionic gonadotropin (triple test). A prospective study of 2892 pregnant women (median age 33.5 years) is reported. The detection rate of Down's syndrome pregnancies was 80% (confidence intervals 45%-100%) when a risk of 1:380 or greater was considered "screen positive", the false positive rate was 13.3% (confidence intervals 12.0%-14.5%). The importance of the accurate assessment of gestational age and the time of blood sampling are emphasized. Our findings are compared with similar studies performed in other laboratories.

Adult↗
PubMed1994

[An outpatient regimen for dental improvements in patients with valvular cardiopathies and oral anticoagulant therapy (a preliminary note)].

The purpose of this paper is to verify the level of confidence of a new approach to the management of patients with cardiovalvular prosthetic and oral treatment with anticoagulants during high level risk oral surgery procedures. The new protocol includes: interrupted oral anticoagulant treatment; ambulatory regimen instead of hospital regimen; special dentistry management. No hemorrhagic complications occurred in the study sample. This paper concludes with a review of the role of Quick test in the management of patients with cardiac prostheses.

Administration, Oral↗
PubMed1993

Comparison of clinical treatment decisions with US National Institutes of Health consensus indications for lower third molar removal.

Treatment decisions about lower third molar surgery have important clinical and cost implications. Although indications for surgery have been the subject of a National Institutes of Health (NIH) consensus conference at which several unambiguous criteria were agreed, no prospective investigations have been carried out to compare clinic treatment decisions with these consensus criteria. Treatment decisions made by six Hospital Service oral surgeons were therefore evaluated for 72 consecutive patients (28 men, 44 women) aged 15-44 years (mean age 25 years), referred for lower third molar assessment. The presence of local disease; recurrent pericoronitis; caries not amenable to restorative measures; follicular cyst formation; internal/external resorption and periodontal disease was recorded by an independent observer immediately after treatment planning had been completed. Of the 139 third molars present, 55 were unerupted, 79 partially erupted and 5 fully erupted. Thirty patients had been scheduled for surgery under general anaesthesia (GA), 36 under local anaesthesia and six patients had not been scheduled for surgery. A total of 42 teeth, according to NIH consensus criteria, had no indications for removal, of which 27 had been scheduled for surgery. These excluded disease-free contralateral teeth that had been scheduled for removal under GA. When a single episode of pericoronitis was excluded as a valid indication, 39 teeth did not meet criteria for removal but had been scheduled for surgery. It was concluded that two-thirds of lower third molars not meeting NIH consensus criteria for surgery had been scheduled for removal. The reasons for this, which may include inappropriate criteria, require further research.

Adolescent↗
PubMed1993

[The effects of protein-energy deficiency in candidates for gastric resection].

The nutritional status of patients subjects to surgical operations represent an important element in determining the incidence of morbidity and mortality. We have examined 19 patients suffering both from benign and from malignant pathology subjected to a gastric resection and treated in the preoperative period for 7-8 days and in the postoperative period for 8-10 days with parenteral nutrition. Nutritional valuation was carried on at the time of admission, in the postoperative period and in proximity to discharge; an accurate observation of possible associated was also carried on. The comparison with the not treated with a nutritional support has shown a smaller incidence in complications of a general character and also in those connected with the operation and a reduction in the postoperative stay in hospital.

Aged↗
PubMed1993

Induction of the murine "W phenotype" in long-term cultures of human cord blood cells by c-kit antisense oligomers.

The murine white (W) spotting locus is the site of the c-kit gene and encodes a tyrosine kinase receptor while the complementary Steel (Sl) locus encodes its ligand. Mutations at either locus have profound effects on hematopoiesis, particularly erythroid and mast cell proliferation. We added c-kit antisense oligonucleotides to long-term suspension cultures of enriched human umbilical cord progenitor cells. This resulted in the suppression of c-kit gene expression and the preferential suppression of the generation of erythroid burst-forming cells (BFU-E) which extended over the life of the culture (3 weeks). The results provide an in vitro model of the "W phenotype" in human hematopoiesis and confirm the importance of c-kit gene function in early erythropoiesis. Because the generation of BFU-E was suppressed even after c-kit gene expression had recovered, this gene product may be critical to the erythroid commitment process.

Animals↗
PubMed1993

Biparietal diameter and crown-rump length in fetuses with Down's syndrome: implications for antenatal serum screening for Down's syndrome.

OBJECTIVES: 1. To compare the ultrasound biparietal diameter and crown-rump length of fetuses with and without Down's syndrome in the first half of pregnancy; 2. To investigate the effect of estimation of gestational age using either measure on the detection rate of serum screening for Down's syndrome. DESIGN: Matched case-control study. Cases were singleton Down's syndrome pregnancies with a biparietal diameter or a crown-rump length recorded. Five controls were matched to each case on: medical centre; the date of the ultrasound scan examination (within two years); gestational age measured as the number of days since the first day of the last menstrual period; and the ultrasound measure used (ie the biparietal diameter (the measure of choice), or the crown-rump length otherwise). If a woman had a serum screening test for Down's syndrome, the biparietal diameter or crown-rump length measurement had to be taken prior to the screening test so that the result of the test could not influence whether a scan was performed. SETTING: Ten antenatal screening centres in seven countries in Europe and North America. SUBJECTS: Two hundred and one women with singleton Down's syndrome pregnancies and 1005 women with unaffected singleton pregnancies. RESULTS: The median biparietal diameter of fetuses with Down's syndrome was identical to that among the controls (median difference 0.0 mm, 95% confidence intervals (CI) -0.5 to 0.5 mm). The estimates of gestational age based on biparietal diameter yielded a median gestational age less than that based on the women's last menstrual period: three days less for cases and two days less for controls; small but statistically significant differences probably reflected a minor systematic difference in the conversion of a biparietal diameter to a gestational age estimate. The median crown-rump length of fetuses with Down's syndrome was also identical to that among controls (median difference 0.0 mm, 95% CI-1.5 to 2.0 mm). There was no significant difference between the median gestational age estimate based on crown-rump length and that based on the women's last menstrual period. CONCLUSION: In antenatal screening for Down's syndrome the routine use of an ultrasound biparietal diameter or crown-rump length measurement to estimate gestational age will not adversely affect the detection rate. To avoid differences in gestational age estimates using the last menstrual period and the biparietal diameter influencing screening performance, separate medians should be derived for each serum marker using the two methods of estimating gestational age. The appropriate set of medians can then be used to calculate the multiple of the median value for each woman screened depending on the method used to estimate her gestational age.

Case-Control Studies↗
PubMed1993

Role of ageing, chronic renal failure and dialysis in the calcification of mitral annulus.

Mitral annulus calcification, a common lesion of the elderly (over age 60 years), has been detected with increased frequency and at younger ages in patients with uraemia. To date a pathogenic role for dialysis and secondary hyperparathyroidism has been suggested only on the basis of older dialytic age and increased serum iPTH observed in the affected individuals. Because this is a potentially dangerous lesion we deemed it useful to evaluate more completely the respective roles of possible pathogenetic factors in uraemic individuals. Evaluation included echocardiography, ECG, limb radiography, and serum assays. A total of 225 dialysis (HD) patients, 67 chronic renal failure (CRF) patients on conservative treatment and 67 normal subjects were studied. Mitral annulus calcification was detected in 87 of 225 (38.6%) HD patients, 11 of 67 (16.4%) CRF and six of 67 (8.9%) normals. In HD, patients with calcification were older and on longer-term renal replacement therapy compared to those without calcification. They also had greater values of iPTH, BGP, AP, and Rx score of secondary hyperparathyroidism. Mitral annulus calcification was associated more frequently (chi 2 = 14.8; P < 0.0001) with rhythm and cardiac conduction defects, but not with ectopic calcifications. Multiple stepwise regression analysis, with mitral annulus calcification score as dependent variable, selected dialysis duration, age, and iPTH (rm = 0.368) as the most predictive parameters, with the first two carrying most of the information. The stratification of patients according with these two parameters showed a progressive increase in the frequency of calcification both with HD duration and age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Aging on the waiting list: should it be a further criterion for cadaver kidney allocation?

Transplant recipients have been selected from our dialysis patients mainly according to the criteria of the best HLA match and the best clinical condition. We have observed that, in using these criteria, most of the patients who receive transplants in the first 2 years on the waiting list. The other patients remain on the waiting list with progressively less chance of transplantation due to a deterioration of their clinical condition and the related increase in risk factors.

Age Factors↗
PubMed1992

Fertility and semen quality of workers exposed to high temperatures in the ceramics industry.

The objective of this study was to test the hypothesis that chronic occupational exposure to high temperatures may be detrimental to male reproduction. The study was based on 92 healthy ceramics oven operators with a long exposure to high temperatures, and 87 controls, recruited from the shipment department of the same industry. Interviews with all subjects provided data on sociodemographic characteristics, health status, and fertility problems. Semen analysis was carried out on 46 of the workers exposed to high temperatures, and 14 of the controls, and included evaluation of the sperm concentration, morphology, and motility, including computer-assisted sperm motion analysis (velocity, linearity, ALH, BCF). The results of the questionnaire showed that exposed individuals had a higher incidence of childlessness and of self-reported difficulty in conceiving than controls. The semen analysis showed no significant differences except in sperm velocity. Although differences in semen parameters, taken singly, were not statistically significant, the overall evaluation of the sperm parameters indicated a higher prevalence of pathologic sperm profiles among the exposed compared to the controls.

Adult↗
PubMed1991

Screening for fetal Down's syndrome with maternal serum markers--an experience in Italy.

The effectiveness of maternal serum alpha-fetoprotein, unconjugated oestriol, and human chorionic gonadotrophin in screening for Down's syndrome (DS) was evaluated on 840 women who underwent amniocentesis for fetal karyotype on account of their age. The risk of a DS pregnancy was established using the method of Wald et al. (1988b), which combines the age-specific risk with that indicated by the levels of the three serum markers. In women over 35, at cut-off risk levels of 1:250 and 1:380, the false-positive rate was 24 and 34 per cent, respectively. In all nine cases of DS, the estimated risk was higher than 1:250. The best screening strategy with the lowest false-positive rate was obtained by combining the three serum markers. The results suggest that this kind of screening can be proposed during genetic counselling for women under 35 and older women wishing to avoid the risk of miscarriage induced by amniocentesis.

Adult↗
PubMed1991

MCS/SEL/BAS program--an overlapping clustering method with examples from mating type interactions of ciliated protozoa.

The MCS/SEL/BAS program provides a method for group recognition, based on a criterion of homogeneity within the groups. The basic aim of this clustering method is not to 'force' data into a number of separate groups, as it allows the possibility that a given element in the data set can be assigned to more than one group. Moreover, a parsimonious path through the groups is sought by selecting groups on the basis of two suitably chosen, peak-ordered criteria. This selection continues until a covering of the data set is obtained (i.e., until each element in the data set is assigned to at least one group). Then relationships occurring among the set of selected groups are investigated by means of two coefficients, called overlapping and cohesion coefficient, respectively. The utility of this program has been demonstrated here in elaborating large sets of data derived from mating type interactions of ciliates, but it can be used also for analyzing data derived from a wide spectrum of compatibility phenomena exhibited by other living organisms. Algorithms of this program are written in BASIC and formulated in a conversational mode for processing on a Macintosh. A computer program (MCS/SEL/BAS) is available from G. Mancini upon request.

Algorithms↗