Gene symbol: NAGLU. Disease: Sanfillipo syndrome B.
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Biomedical subjects
Publications and source records attributed to D Vitale.
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Arabidopsis thaliana is an important model system for plant biologists. In 1996 an international collaboration (the Arabidopsis Genome Initiative) was formed to sequence the whole genome of Arabidopsis and in 1999 the sequence of the first two chromosomes was reported. The sequence of the last three chromosomes and an analysis of the whole genome are reported in this issue. Here we present the sequence of chromosome 3, organized into four sequence segments (contigs). The two largest (13.5 and 9.2 Mb) correspond to the top (long) and the bottom (short) arms of chromosome 3, and the two small contigs are located in the genetically defined centromere. This chromosome encodes 5,220 of the roughly 25,500 predicted protein-coding genes in the genome. About 20% of the predicted proteins have significant homology to proteins in eukaryotic genomes for which the complete sequence is available, pointing to important conserved cellular functions among eukaryotes.
Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI, MPS VI) is an autosomal recessive disorder due to the deficiency of the lysosomal enzyme N-acetylgalactosamine-4-sulfatase (arylsulfatase B, ASB). Mutation analysis in Maroteaux-Lamy syndrome resulted in the identification of approximately 40 molecular defects underlying a great genetic heterogeneity. Here we report five novel mutations in Italian subjects: S65F, P116H, R315Q, Q503X, P531R; each defect was confirmed by restriction enzyme or amplification refractory mutation system (ARMS) analysis. We also performed a three-dimensional (3-D) structure analysis of the alterations identified by us, and of an additional 22 point mutations reported by other groups, in an attempt to draw helpful information about their possible effects on protein conformation.
We report a novel case of multiple endocrine neoplasia type 2A (MEN 2A) associated with two mutations of the protooncogene RET. One affects codon 634 and causes a cysteine to arginine substitution; the second at codon 640 causes an alanine to glycine substitution in the transmembrane region. The two mutations were present on the same RET allele and were detected in germline and tumor DNA. Both mutations were de novo, i.e. they were not found in the DNA of the parents or relatives. Immunohistochemical and RT-PCR analysis showed that the pheochromocytoma expressed calcitonin as well as both RET alleles. A cell line established from the tumor and propagated in culture sustained the expression of RET and calcitonin, as did the original pheochromocytoma. Because the patient presented with medullary thyroid carcinoma and pheochromocytoma without parathyroid gland involvement, we speculate that this clinical picture could be correlated with the two RET mutations and to the unusual calcitonin production. This is the first report of a MEN 2A case due to two mutations of the RET gene and associated with a calcitonin-producing pheochromocytoma.
AIM: The authors evaluate the value of hepatic intrarterial chemotherapy (HAC) as an alternative treatment for hepatic metastases from colo-rectum cancer unsuited to radical surgery. METHODS: This study evaluates the physiopathological and pharmacodynamic bases for this type of treatment, the correct procedure for patient staging and selection, the surgical technique used to insert the infusional system, surgical complications and those linked to endoarterial treatment, the evaluation of response and the results. Complications correlated to the infusional system were evaluated in a total of 1223 patients in 10 non-randomised studies and 7 randomised studies taken from the literature. Complications correlated to chemotherapy were analysed in a total of 777 patients from 8 randomised studies and 7 randomised using FUDR. Special emphasis was placed on the possible association of locoregional and systemic treatment in order to prevent extrahepatic progression, the main cause of death in patients undergoing a single cycle of HAC. RESULTS: By comparing locoregional and systemic treatment taken from a number of randomised and non-randomised studies, the results were evaluated in terms of objective response and survival. CONCLUSIONS: There was no proportional increase in survival rates compared to systemic treatment only, in spite of the large proportion of objective responses achieved using locoregional treatment alone.
The recently-identified Wiskott-Aldrich syndrome protein gene (WASP) is responsible for the Wiskott-Aldrich X-linked immunodeficiency as well as for isolated X-linked thrombocytopenia (XLT). To characterize the regulatory sequences of the WASP gene, we have isolated, sequenced and functionally analyzed a 1.6-Kb DNA fragment upstream of the WASP coding sequence. Transfection experiments showed that this fragment is capable of directing efficient expression of the reporter chloramphenicol acetyltransferase (CAT) gene in all human hematopoietic cell lines tested. Progressive 5' deletions showed that the minimal sequence required for hematopoietic-specific expression consists of 137 bp upstream of the transcription start site. This contains potential binding sites for several hematopoietic transcription factors and, in particular, two Ets-1 consensus that proved able to specifically bind to proteins present in nuclear extracts of Jurkat cells. Overexpression of Ets-1 in HeLa resulted in transactivation of the CAT reporter gene under the control of WASP regulatory sequences. Disruption of the Ets-binding sequences by side-directed mutagenesis abolished CAT expression in Jurkat cells, indicating that transcription factors of the Ets family play a key role in the control of WASP transcription.
Deficiency of the R-type pyruvate kinase (R-PK) causes an autosomal recessive, hereditary, nonspherocytic hemolytic anemia (HNSHA). We screened seven unrelated patients from the south of Italy for the known mutations and found one patient homozygous for the 1529A (R510Q) mutation, two others bearing the 1456T (R486W) mutation, one homozygous and another heterozygous, and two heterozygotes for the 994A mutation (G332S). We also found three novel mutations at the heterozygote status: a G to C transversion in position 1010 (1010C; R337P) and a C to T transition in position 1492 (1492T; R498C), which are missense, and a T to G transversion in position 1523 (1523G; L508Z), which produces a stop codon with a subsequent loss of the C-terminal protein domain. The structural features of R-PK in the mutation-bearing regions were examined. In all cases the mutations altered the local conformation of the enzyme. Both G332S and R337P are in highly conserved sequence regions. In particular, the R337P mutation significantly affects the intersubunit interactions, because it is located in a region subjected to a large conformational change that occurs during the R-->T allosteric transition, which is essential for the enzyme activity. The R486W mutation affects an external pocketlike region, producing only a local conformational change; the R498C mutation changes the interactions among neighbouring residues; the R510Q mutation involves the loss of interdomain interactions that may reduce enzyme stability and activity. Our data also indicate that in patients from Southern Italy, pyruvate kinase deficiency is heterogeneous, the 1529A mutation, which is the most frequent mutation in the U.S. Caucasian population, having a lower frequency.
PURPOSE: We analyzed the blood of patients with lung cancer at different stages of presentation for the presence of carcinoembryonic antigen (CEA) mRNA detected by reverse transcriptase-polymerase chain reaction (RT-PCR) combined with the dot-blot procedure as an indicator of micrometastatic malignant cells. PATIENTS AND METHODS: We studied 24 lung cancer patients (10 with distant metastases and 14 with no evidence of distant metastases), eight age- and sex-matched patients affected by nonneoplastic respiratory diseases (four smokers), and eight healthy subjects. We used immunohistochemistry and RT-PCR dot-blot analysis to evaluate CEA expression in the neoplastic tissue, and the RT-PCR dot-blot procedure to analyze CEA mRNA in circulating cells. RESULTS: The RT-PCR dot-blot procedure was highly sensitive aspecific: it detected CEA mRNA in samples of RNA from lung cancer diluted 10(6)-fold with RNA extracted from normal blood cells, and sequence analysis confirmed that the amplified product was CEA. CEA mRNA was found in circulating cells from eight of 10 lung cancer patients with distant metastases (diagnostic sensitivity, 80%) and in four of 14 patients with no evidence of distant metastases. Two of the latter had distant metastases within 6 months of analysis. Thus, the diagnostic specificity of the analysis toward lung cancer without distant metastases was 86%. The analysis was negative in the eight nonneoplastic patients and in the eight healthy controls. CONCLUSION: The RT-PCR dot-blot analysis of CEA mRNA in blood cells seems to be a promising tool for the early detection of micrometastatic circulating cells in patients with lung cancer.
A multicenter, double-blind, randomized, placebo-controlled trial was conducted to assess the effects of verapamil on total mortality, cardiac mortality, reinfarction, and angina after an acute myocardial infarction. All patients, aged 30 to 75 years, consecutively admitted for acute myocardial infarction between 1985 and 1987 to the participating centers, and without contraindications to verapamil or history of severe heart failure were enrolled. Seven to 21 days (mean 13.8) after myocardial infarction, 531 patients were randomized to verapamil retard 360 mg/day, and 542 patients to placebo. At baseline, the 2 groups of patients had similar characteristics. Mean age was 55.5 years and 91% were men. During a mean follow-up of 23.5 months, 5.5% of the patients died. No differences between verapamil and placebo were observed in total mortality (n = 30 and 29, respectively) and cardiac death (n = 21 and 22, respectively). The verapamil group had nonsignificant lower reinfarction rates (n = 39 vs 49). The number of patients developing angina was significantly less in the verapamil group (n = 100 vs 132, RR = 0.8, 95% confidence interval 0.5 to 0.9). There were no differences in discontinuation of therapy caused by adverse reactions. This trial showed no effect of verapamil on mortality. The lower reinfarction rates found in the verapamil group are in agreement with the results of other studies.
The pathophysiological basis for the use of metabolic therapy in the treatment of heart failure is analyzed. Bioenergetical processes related to ATP bioavailability play a central role in regulating myocardial contractility at rest and on effort. Furthermore, a significant correlation has been demonstrated in diseased heart between ATP content, revealed at endomyocardial biopsy, and systolic and diastolic left ventricular indexes evaluated with invasive and noninvasive methods. Several international investigations demonstrate the beneficial effects of ubiquinone (coenzyme Q10) in the treatment of heart failure. Here the results of a study are reported that was conducted on patients with heart failure treated with ubiquinone. After 7 months of oral drug administration (100 mg/day), a significant improvement was observed in echocardiographic indexes of systolic function, cardiothoracic ratio, and clinical signs and symptoms of congestive heart failure. In conclusion, the introduction of metabolic drugs, such as ubiquinone, in the treatment of heart failure opens new horizons in the therapeutic approach to an ailment that entails substantial human and social costs.
In a study of 87 patients with chronic hepatitis C, 12 months' treatment with interferon alfa-2b at a dose of 6 million units (MU) three times per week seemed to be more effective than treatment with 3 MU three times a week for two months plus 1.5 MU three times a week for 10 months in increasing the percentage of long term responders. The percentage of patients in whom alanine amino-transferase activities returned to normal was highest in the 6 MU group, as was the percentage of responders who sustained this normal activity after treatment. Side effects were moderate and self-limited in most patients.
BACKGROUND: We studied the effect of intracoronary administration of arginine-8-vasopressin on blood flow in nondiseased coronary arteries and determined whether this vasoconstriction was severe enough to produce ischemia in 30 dogs. METHODS AND RESULTS: In group 1 (n = 6), after vasopressin administration coronary blood flow was decreased by 41% (p less than 0.002) without changes in heart rate or aortic pressure, and left ventricular ejection fraction measured by radionuclide angiocardiography was decreased by 18% (p less than 0.0005). In group 2 (n = 6), ischemia was confirmed by measurement of transmural pH changes. Administration of vasopressin decreased subendocardial pH of the infused zone from 7.40 +/- 0.03 to 7.31 +/- 0.07 (p less than 0.01). The subendocardial pH of the zone not infused with vasopressin did not change. To overcome the intrinsic regulation of blood flow, operating primarily in small coronary arteries, we hypothesized that vasopressin must increase resistance primarily in large rather than small coronary arteries. After intracoronary infusion in group 3 (n = 6), however, most (94%) of the increase in resistance during vasopressin administration was explained by an increase of resistance in small coronary arteries. In group 4 (n = 9), vasopressin decreased coronary blood flow by 50% and decreased local shortening by 90% at a time when systemic hemodynamics were unchanged. Coronary constriction induced by vasopressin, or the recovery from it, also was not altered by cyclooxygenase blockade. CONCLUSIONS: Thus, vasopressin produces myocardial ischemia by constricting small, nondiseased coronary arteries severely enough to overcome the competition from normal coronary regulation, and this ischemic event is not mediated by prostaglandin products.
Several studies have demonstrated that physiological aging significantly affects cardiovascular function. Experimental researches, conducted on cardiac muscle of senescent animals, have shown a prolongation of both contraction and relaxation times. This phenomenon was explained by a reduced Ca(++)-stimulated ATPase pump activity, responsible for the reduced sarcoplasmic reticulum Ca++ uptake rate. The myofilament response to Ca++ in the aging heart is normal as are peak contractile force production and post-extrasystolic twitch potentiation during continual paired stimulation. On the other hand, the inotropic response to cardiac glycosides and beta-adrenoceptor stimulation is diminished in senescent compared to adult myocardium. This decreased contractility could result mainly from mechanisms controlling Ca++ reuptake from sarcoplasmic reticulum and relaxation time (diastolic phase) rather than those determining force generation and contraction time (systolic phase). Age-related physiologic structural changes are not associated with significant variations in left ventricular diastolic and systolic sizes, but they seem a direct consequence of the rising systolic blood pressure observed in these age decades. Myocardial hypertrophy should not be considered a specific marker of the senescent heart, but rather an adaptive response to increased afterload conditions. As regard the relationship between age and diastole, it is important to underline that the alterations in aging cardiac muscle function primarily involve the isovolumic relaxation time and diastolic phase. With age, the early diastolic phase declines while the contribution of atrial contraction to ventricular diastolic filling increases as well as the isovolumic relaxation time.(ABSTRACT TRUNCATED AT 250 WORDS)
Natural history and prognostic factors of dilated cardiomyopathy in pediatric age are not well identified so far. The course of the disease, often, presents "odd" characteristics: some of the patients show clinical improvement, someone remains unchanged and some of them have a negative evolution in a very short time. It is necessary to identify the group of patients having a poor outcome in order to define prognostic factors of impending death so that a cardiac transplant could be offered to them as a reasonable therapeutic choice. Twenty-two children, 9 males and 13 females (median age 5 +/- 5 years) with dilated cardiomyopathy were studied. Their natural history was followed for a period of 40 +/- 30 months. Clinical data, laboratory studies (electrocardiogram, Holter monitoring, echocardiogram M-mode, 2-D, Doppler and chest X-ray) were taken into consideration. At the end of follow-up period 7 patients showed improvement in cardiac status (31.8%), 7 remained unchanged (31.8%) and 8 (36%) got worse; 9 died. The survival curve showed a rate of 72% at 12 months and of 59.3% at 60 months. Of 9 died patients, 2 died suddenly and seven for congestive heart failure. Clinical findings and laboratory investigations of 13 survived patients (Group I) and 9 died patients (Group II) were compared to establish the risk factors of poor outcome. The fractional shortening is the only significant factor of poor outcome (p less than 0.025). Other negative factors were identified more in Group II than in Group I.(ABSTRACT TRUNCATED AT 250 WORDS)
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Although alpha-adrenergic stimulation can increase coronary vascular resistance, it remains unknown whether the vasoconstriction can override intrinsic coronary regulatory influences to produce ischemia. Methoxamine, 2 to 4 mg, was infused into the circumflex coronary artery of 23 chloralose-anesthetized open chest dogs, and resulted in a 68% increase in coronary vascular resistance. The functional consequence of this increased coronary vascular resistance was assessed by gated radionuclide ventriculography and ST-T wave changes on the electrocardiogram. In six dogs (Group I), aortic pressure changed trivially (less than 5 mm Hg) to allow distinction between direct effects of the flow reduction and indirect effects of increased aortic pressure. In this group, coronary blood flow decreased 33% from a control value of 44 +/- 10 ml/min (p less than 0.001) and left ventricular ejection fraction decreased from 0.54 +/- 0.12 to 0.46 +/- 0.10 (p less than 0.025). In eight dogs (Group II) in which aortic pressure increased by more than 5 mm Hg, left ventricular ejection fraction decreased from 0.46 +/- 0.07 to 0.39 +/- 0.09 (p less than 0.002). Pressure gradients were measured between the aorta and a distal coronary artery branch to calculate small and large vessel resistances separately in four other dogs (Group III). The resistance of small coronary arteries accounted for 92% of the total increase in coronary vascular resistance produced by methoxamine. In five other dogs (Group IV), intracoronary methoxamine, 2 mg, produced ST-T wave changes suggestive of ischemia as it increased coronary vascular resistance by 33%.(ABSTRACT TRUNCATED AT 250 WORDS)
We evaluated the protective effect of Diltiazem from pacing-induced myocardial ischemia in 9 patients (pts) with coronary heart disease (CAD) and stable effort angina by studying the changes in systemic and coronary hemodynamics during pacing. Hemodynamic parameters were evaluated at baseline and at peak pacing before and after Diltiazem, 25 mg i.v. Diltiazem prevented angina in 6 of 7 pts who presented angina in the control pacing. This beneficial effect was accompanied at peak pacing rate by a significant fall in ST depression, arterial pressure, rate-pressure product and left ventricular (LV) end-diastolic pressure, while no significant changes were observed in LV dp/dt max, coronary blood flow and coronary vascular resistance. Therefore, Diltiazem exerts a protective effect from pacing-induced myocardial ischemia in pts with CAD and stable effort angina, without impairing LV function. This beneficial effect is due to a reduction in myocardial metabolic requirements, rather than to an improvement of blood supply to the ischemic myocardium.
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