Biomedical subjects
Publications and source records attributed to S Palmieri.
A case of prenatal diagnosis of 22q11 microdeletion in a fetus with a conotruncal heart defect is described. This type of chromosomal aberration has been shown to be present in up to 30% of isolated conotruncal anomalies and in most cases of DiGeorge and velocardiofacial syndromes. The implications of such a diagnosis on prenatal counselling are discussed.
The prenatal diagnosis of various forms of left ventricular outflow tract obstruction has been reported in detail. However, the appearance and the characteristics of fetal aortic insufficiency have been described only in association with complete absence of the value. We report here a case of aortic insufficiency associated with severe aortic stenosis. Features characteristic of insufficiency were severe cardiomegaly due to left ventricle dilatation and the hypocontractility of the myocardium. The aortic root was enormously dilated and the semilunar valve showed thick and dysplastic cusps. On color Doppler, the retrograde high-velocity regurgitant jet was clearly visible.
Viruses are recognized to be the major cause of respiratory infections. Clinical and experimental evidence also supports an important role for viruses in the pathogenesis of lower airway disease and asthma exacerbation. In prospective epidemiological studies, 80% of asthma exacerbations in school-aged children and half of all asthma exacerbations in adults have been associated with viral upper respiratory infections. Human rhinovirus (HRV) has been implicated as the principal virus associated with asthma exacerbation. In our studies on respiratory viruses, we have observed two clinical patterns of presentation. The viruses can either be a precipitating factor of respiratory illness characterized by a typical clinical onset, or can induce an atypical clinical onset such as haemoptysis, pleuritis, spontaneous pneumothorax and asthmatic syndrome. Thus the observed clinicoradiological and functional features during atypical viral respiratory infection may be correlated to the long-term biological effects induced by previous and concurrent infections.
BACKGROUND: Myrosinase is the enzyme responsible for the hydrolysis of a variety of plant anionic 1-thio-beta-D-glucosides called glucosinolates. Myrosinase and glucosinolates, which are stored in different tissues of the plant, are mixed during mastication generating toxic by-products that are believed to play a role in the plant defence system. Whilst O-glycosidases are extremely widespread in nature, myrosinase is the only known S-glycosidase. This intriguing enzyme, which shows sequence similarities with O-glycosidases, offers the opportunity to analyze the similarities and differences between enzymes hydrolyzing S- and O-glycosidic bonds. RESULTS: The structures of native myrosinase from white mustard seed (Sinapis alba) and of a stable glycosyl-enzyme intermediate have been solved at 1.6 A resolution. The protein folds into a (beta/alpha)8-barrel structure, very similar to that of the cyanogenic beta-glucosidase from white clover. The enzyme forms a dimer stabilized by a Zn2+ ion and is heavily glycosylated. At one glycosylation site the complete structure of a plant-specific heptasaccharide is observed. The myrosinase structure reveals a hydrophobic pocket, ideally situated for the binding of the hydrophobic sidechain of glucosinolates, and two arginine residues positioned for interaction with the sulphate group of the substrate. With the exception of the replacement of the general acid/base glutamate by a glutamine residue, the catalytic machinery of myrosinase is identical to that of the cyanogenic beta-glucosidase. The structure of the glycosyl-enzyme intermediate shows that the sugar ring is bound via an alpha-glycosidic linkage to Glu409, the catalytic nucleophile of myrosinase. CONCLUSIONS: The structure of myrosinase shows features which illustrate the adaptation of the plant enzyme to the dehydrated environment of the seed. The catalytic mechanism of myrosinase is explained by the excellent leaving group properties of the substrate aglycons, which do not require the assistance of an enzymatic acid catalyst. The replacement of the general acid/base glutamate of O-glycosidases by a glutamine residue in myrosinase suggests that for hydrolysis of the glycosyl-enzyme, the role of this residue is to ensure a precise positioning of a water molecule rather than to provide general base assistance.
Epidemiological and pharmacological studies have shown that colorectal cancer development could be reduced by consuming vegetables that contain glucosinolates. In view of this the effect of some glucosinolates and their isothiocyanate (ITC)-derived products on in vitro cell growth was studied. We report the isolation and characterization of ITCs derived from glucosinolates by using HPLC, GC-MS, and NMR techniques. The in vitro activity of ITCs on human erythroleukemic K562 cells has been investigated by using two alternative approaches: the in situ and pre-mix methods. No differences in antiproliferative activity were found comparing the effect of ITCs produced either of these methods. In the experimental conditions used, the production of ITCs from glucosinolates is almost quantitative as confirmed by HPLC or GC-MS analysis. The ITCs' inhibitory activity on K562 cells growth is particularly evident in the cases of ITCs derived from sinigrin, progoitrin, epi-progoitrin, glucotropaeolin and glucocheirolin. Finally, the antiproliferative activity of the ITCs obtained from glucoraphenin, taken as an example, was determined on other tumor cell lines with a different origin and hystotype. Considering the antiproliferative activity found for ITCs these compounds could be considered potentially responsible for the reduction of colorectal cancer associated with diets rich in cruciferous vegetables. Further studies will be aimed at the possible application of glucosinolate-derived products as chemopreventive cancer agents.
The objective of this study was to assess the feasibility of recording pulmonary venous blood flow in the human fetus, and to evaluate its relationship with gestational age. We studied 152 singleton pregnancies between the 19th and 40th weeks of gestation. One hundred and one cases were studied cross-sectionally to gather data on color flow visualization, and 51 were studied longitudinally. The upper right pulmonary vein was interrogated by pulsed wave Doppler to assess pulmonary venous blood flow. On color Doppler, the upper right pulmonary vein could be imaged in 89.6% of cases in the peri-atrial tract and in 75% of cases within the lung. The upper left pulmonary vein could only be imaged in 8% of cases close to the atrium and in 41% of cases within the lung. Reliable velocity waveforms were obtained in 91% of cases. The mean systolic peak velocity was 22.19 +/- 6.39 cm/s and the mean diastolic peak velocity was 22.1 +/- 6.35 cm/s. Both increased significantly with gestational age. Reversed end-diastolic blood flow was present in 18% of cases, regardless of gestational age and fetal heart rate. Expressed as a percentage of the forward flow velocity time integral, its value was 7.65 +/- 5.2%. Our data seem to confirm the presence of pulsatile pulmonary venous blood flow in the second- and third-trimester fetus. Normative data have been established for the second and third trimesters of pregnancy.
Arrested myocardial development, often described as spongiosum heart, has been reported in association with obstructive semilunar valve disease and, much more rarely, as a primary disease in adolescents and adults. To our knowledge, this condition has never been diagnosed in utero. We describe the echocardiographic and pathoanatomic findings of the 1st case of myocardial dysplasia detected in utero by ultrasound. A 28-year-old woman, gravida 2, para 1, was referred to our unit at 34 weeks of gestation due to severe fetal hydrops. On echocardiography, we observed gross fetal cardiomegaly (particularly of the septal and ventricular myocardium), an unusually bright myocardial echostructure, thick trabeculations in both ventricular chambers, and severe loss of myocardial contraction. There were normal ventriculoarterial connections and no signs of obstructive semilunar valve disease. After fetal death, necropsy confirmed the presence of spongiosum heart and the diagnosis of myocardial dysplasia--which term best describes this disorder in its various temporal expressions. Because this condition has never before been observed prenatally, no consideration has been given to intrauterine management. We recommend that fetal cardiac function be monitored echocardiographically whenever a pregnant patient has a positive family history of this disease. There is a possibility that the life of the affected fetus might be prolonged beyond the gestational period by avoiding intrauterine cardiac decompensation, through early delivery. We recommend further that the parents of these children be advised of the risks associated with future pregnancies. Little is known about the pattern of inheritance of myocardial dysplasia, but the disorder appears to be familial. Therefore, the possibility that it may recur within the same generation must be taken into account.
Using synthetic deoxy-glucotropaeolins (6d-GTL, 4d- GTL, 3d-GTL, 2d-GTL) as substrates, myrosinase activity was studied in comparison to that determined on native glucotropaeolin (GTL) isolated from ripe Lepidium sativum seeds. When the deoxy substrates were used, in addition to an overall strong reaction rate decline, a significant decrease in the reaction rate was observed in going from 6d- to 2d-GTL. This finding allows us to propose a mechanism of catalysis which appears to be similar in many respects to that established for beta-glucosidases. Finally, 2d-GTL was shown to be the first strong competitive inhibitor of myrosinase ever reported.
BACKGROUND: We describe a case of arteriovenous fistula of the middle and posterior cerebral arteries detected in a fetus. CASE: Fetal echocardiography revealed a high-output cardiac failure. Color Doppler ultrasound demonstrated an arteriovenous fistula, localized at the middle and posterior cerebral arteries, which drained in a large venous aneurysm occupying the posterior fossa. The aneurysm caused cerebellar dislocation and temporal lobe hypoplasia. Necropsy after pregnancy termination confirmed the ultrasound findings. CONCLUSION: This case demonstrates that malformation of a fetal cerebral artery can lead to brain hypoplasia and thus to severe mental handicap. This possibility needs to be considered in patient counseling.
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Congenital inguinal hernias, relatively common among infants, have rarely been reported in utero. In this brief report, the prenatal diagnosis of this condition based on movement of the intestinal content within the ileal loops is described. The differential diagnosis with other masses protruding from the abdominal wall (omphalocele) or the perineal region (sacrococcygeal teratoma, hydrocele) is discussed.
A case is presented in which the ultrasonographic detection of multiple congenital anomalies led to the diagnosis of Roberts syndrome in the fetus of a woman with a negative family history. The fetus had bilateral cleft lip and palate, bilateral amesomelia with ectrodactyly, a complex congenital heart disease and intrauterine growth retardation. These malformations are frequent in Roberts syndrome and, therefore, an amniocentesis was performed to detect the cytogenetic marker of this syndrome, premature centromere separation. This phenomenon could not be detected in metaphases from amniocytes, but it was present in peripheral lymphocytes cultured at birth. The clinical implications of these findings are discussed. Furthermore, to our knowledge, this represents the first case in which the suspicion of Roberts syndrome was raised by ultrasound in a family with a negative family history.
This retrospective multicenter study represents an analysis of the intrauterine determinants of the prognosis for conotruncal anomalies. Data regarding reason for referral, presence of chromosomal or extracardiac anomalies, pregnancy and surgical outcome were recorded in 67 cases of conotruncal anomalies from three Italian referral units. Chromosomal aberrations effected 11 of the 60 (18.3%) fetuses in which a karyotype was available. Extra-cardiac malformations were present in 25/67 cases (37.3%). No chromosomal anomalies were present in fetuses with complete or corrected transposition of the great arteries. However, tetralogy of Fallot and double-outlet right ventricle were associated with chromosomal anomalies in 22% and 38% of cases, respectively, and with extracardiac anomalies in 45% and 46% of cases, respectively. Only 20 of the 67 (31%) cardiac malformations were associated with an abnormal four-chamber view. There were 28 (41.7%) terminations of pregnancy, six (8.9%) intrauterine deaths and 16 (23.8%) neonatal deaths. Seventeen neonates (25.3%) are currently alive, and 15 of these have undergone reparative surgery. The prognosis of conotruncal anomalies is poorer when the conditions is diagnosed in utero. This is mainly due to the frequent association with chromosomal and/or extracardiac anomalies, often leading to intrauterine or early neonatal death.
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A new serine proteinase inhibitor, rapeseed trypsin inhibitor (RTI), has been isolated from rapeseed (Brassica napus var. oleifera) seed. The protein inhibits the catalytic activity of bovine beta-trypsin and bovine alpha-chymotrypsin with apparent dissociation constants of 3.0 x 10(-10) M and 4.1 x 10(-7) M, at pH 8.0 and 21 degrees C, respectively. The stoichiometry of both proteinase-inhibitor complexes is 1:1. The amino acid sequence of RTI consists of 60 amino acid residues, corresponding to an M(r) of about 6.7 kDa. The P1-P1' reactive site bond has been tentatively identified at position Arg20-Ile21. RTI shows no similarity to other serine proteinase inhibitors except the low molecular weight mustard trypsin inhibitor (MTI-2). RTI and MTI-2 could be members of a new class of plant serine proteinase inhibitors.
A study was conducted into the exposure to atmospheric pollution caused by car traffic by measuring blood lead (PbB) levels in a sample of 657 adult individuals (shopkeepers) all living in Liguria. The mean level of blood lead in all examined individuals was 9.39 micrograms dl-1 (0.45 mumol per liter; C.I. 95%: 9.06-9.75 micrograms dl-1; 0.44-0.47 mumol per liter) with a range between 2.0 and 46.03 micrograms dl-1 (0.10-2.22 mumol per liter). The average Pb values in individuals working in streets with high and very high traffic was 8.30 micrograms dl-1 (0.40 mumol per liter; C.I. 95%: 7.41-9.31 micrograms dl-1; 0.36-0.45 mumol per liter) and 9.98 micrograms dl-1 (0.48 mumol per liter; C.I. 95%: 9.62-10.37 micrograms dl-1; 0.46-0.50 mumol per liter), respectively. These average blood lead levels were statistically greater than the average PbB values of those working in low traffic streets (7.06 micrograms dl-1; 0.34 mumol per liter; C.I. 95%: 6.22-7.94 micrograms dl-1; 0.30-0.38 mumol per liter). The percentile distribution (50th, 90th and 98th P) for all subgroups surveyed has always proved to be below the maximum limits specified by EC Directive No. 77/312.
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OBJECTIVE: To determine the incidence of aneuploidy among fetuses with congenital heart disease diagnosed in utero. METHODS: From June 1988 through December 1991, 502 fetuses at risk for congenital heart disease underwent fetal echocardiography. Fetal karyotyping was performed whenever a cardiac anomaly was diagnosed. Autopsy reports, postnatal echocardiograms, and angiograms were obtained to confirm the diagnosis. RESULTS: Congenital heart disease was found in 31 of 469 fetuses with complete follow-up. Fifteen of these 31 fetuses (48%) were found to have an abnormal karyotype: five of 17 (29.4%) with isolated cardiac anomalies and ten of 14 (71.4%) with cardiac and extracardiac anomalies. Detected chromosomal abnormalities included six trisomy 21, four trisomy 18, four trisomy 13, and one triploidy 69,XXX. Atrioventricular septal defects and ventricular septal defects were the cardiac malformations most often associated with abnormal karyotypes (77 and 71%, respectively). CONCLUSIONS: The risk of aneuploidy associated with fetal cardiac anomalies is much greater than that associated with elevated maternal age; therefore, fetal karyotyping should be offered whenever a cardiac defect is diagnosed. Advanced gestational age should not represent a deterrent, because the discovery of a lethal trisomy in a fetus with a cardiac malformation can affect dramatically the prognosis and the obstetric and neonatal management. We believe that a screening view such as the four-chamber view should now be included routinely in obstetric ultrasound examinations.