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Biomedical subjects

M Palmieri

Publications and source records attributed to M Palmieri.

At least 19 recordsLinked to original sources

p125FAK tyrosine phosphorylation and focal adhesion assembly: studies with phosphotyrosine phosphatase inhibitors.

p125FAK is a major tyrosine kinase phosphorylated in response to integrin-dependent adhesion. In this study we use vanadate and phenylarsine oxide (PAO), known inhibitors of phosphotyrosine phosphatases (PTPases), as a tool to artificially modulate p125FAK phosphorylation in human endothelial and in Chinese hamster ovary cells. Vanadate treatment strongly upregulates in a dose-dependent manner the level of tyrosine phosphorylation of several proteins in adherent cells. PAO induces a more restricted profile of tyrosine-phosphorylated proteins, increasing primarily a broad band of 120-140 kDa. Maximal stimulation of p125FAK tyrosine phosphorylation is reached at 10 microM PAO. In contrast, in vanadate-treated cells the p125FAK tyrosine phosphorylation shows a biphasic curve, being increased at high doses of vanadate (100 microM) and downregulated at low doses (25 microM). Immunofluorescence analysis of cells treated with PTPase inhibitors showed a direct correlation between the level of p125FAK tyrosine phosphorylation and the assembly of focal adhesions and actin stress fibers. Downregulation of p125FAK tyrosine phosphorylation is observed by treating cells with cytochalasin D (CD), a drug known to rapidly disrupt the actin cytoskeleton. When PTPase inhibitors are added in combination to CD, the level of tyrosine phosphorylation of p125FAK remains high and focal adhesions and actin stress fibers are preserved from the CD-mediated disruption. Based on these data we suggest that assembly of actin cytoskeleton plays an important role in inhibiting PTPases involved in p125FAK tyrosine phosphorylation.

Actins

Sequences related to the ox pancreatic ribonuclease coding region in the genomic DNA of mammalian species.

Mammalian pancreatic ribonucleases form a family of homologous proteins that has been extensively investigated. The primary structures of these enzymes were used to derive phylogenetic trees. These analyses indicate that the presence of three strictly homologous enzymes in the bovine species (the pancreatic, seminal, and cerebral ribonucleases) is due to gene duplication events which occurred during the evolution of ancestral ruminants. In this paper we present evidence that confirms this finding and that suggests an overall structural conservation of the putative ribonuclease genes in ruminant species. We could also demonstrate that the sequences related to ox ribonuclease coding regions present in genomic DNA of the giraffe species are the orthologues of the bovine genes encoding the three ribonucleases mentioned above.

Amino Acid Sequence

The effect of dietary fruits and vegetables on urinary galactitol excretion in galactose-1-phosphate uridyltransferase deficiency.

Even on a lactose-restricted diet, urinary galactitol excretion and erythrocyte galactose-1-phosphate levels are persistently elevated in patients with galactose-1-phosphate uridyltransferase deficiency. In order to determine the contribution of galactose in dietary fruits and vegetables to this phenomenon, (1) the content of galactose in a lactose-free diet was directly measured when a galactosaemic patient's diet was specifically enriched in those fruits and vegetables which contain relatively large amounts of free galactose and (2) galactitol excretion was determined during ingestion of this diet for 3 weeks and while on a synthetic diet for 1 week that provided < 8 mg galactose/day. For comparison the effect of a 3-week supplementation of 200 mg galactose/day was determined. The measured intake in total foodstuffs matched the theoretical content of galactose in the patient's diet based on amounts in fruits and vegetables alone, thus supporting the concept that fruits and vegetables are primarily responsible for galactose intake in a lactose-free diet. All of the dietary manipulations, however, had relatively little effect on metabolite levels, suggesting that endogenous galactose production is primarily responsible for the elevated levels of galactose metabolites routinely detected in patients on lactose-restricted diets.

Adolescent

Protein-DNA interactions in the 5'-flanking region of the bovine pancreatic ribonuclease gene.

In the 5'-flanking region of the bovine pancreatic ribonuclease gene a sequence has been identified which specifically binds one or more factors present in nuclear protein extracts prepared from bovine pancreas. The binding site, as delineated by footprinting analysis, is located in a region extending from positions -113 to -146 relative to the transcription initiation site of the ribonuclease gene. This region contains consensus sequences for known control transcriptional elements. The observed pattern of protein-DNA interactions is likely to be pancreas-specific as it could not be detected with nuclear extracts prepared from HeLa or bovine aorta endothelium cells.

Animals

Bone marrow transplantation for Niemann-Pick type IA disease.

Bone marrow transplantation has been undertaken with encouraging results as therapy for a wide variety of lysosomal storage diseases. We report a case of Niemann-Pick disease Type IA in which, despite the presence of only mild hypotonia with depressed reflexes, the clinical course of the disease appeared to be only slightly modified by this procedure, which was performed at the earliest practical opportunity. The patient was diagnosed early when asymptomatic, because of a family history of an affected sibling who died at 14 months. He received a bone marrow transplant from an HLA-identical, MLC non-reactive sibling donor, whose leukocyte sphingomyelinase activity was in the homozygote normal range. There was adequate engraftment as evidenced by persistently normal leukocyte sphingomyelinase activities, and there was no evidence of graft-versus-host disease. Visceral storage and neurological impairment were less rapidly progressive than in his untreated sibling but he eventually died at 30 months. Autopsy confirmed that this was essentially due to the effects of the underlying Niemann-Pick disease. We conclude that despite some success in other neurovisceral lysosomal storage disorders, bone marrow transplantation is not likely to be an adequate treatment for Niemann-Pick disease Type IA.

Bone Marrow Transplantation

A pancreatic-like ribonuclease is synthesized in rat brain.

The distribution and cell localization of a pancreatic-like ribonuclease (RNAase) in the rat brain has been studied by RNA blot analysis and in situ hybridization using as a probe the cDNA coding for the rat pancreas RNAase, and by immunocytochemistry using an antiserum raised against the rat pancreas RNAase. RNA blot analysis and in situ hybridization experiments have shown that the RNAase mRNA is present in all the cerebral areas investigated and that neurons appeared to be actively expressing RNAase mRNA while glial cells were devoid of hybridization signals. In agreement with these results the immunocytochemical analysis has shown that neurons are specifically immunostained. These experiments demonstrate that a pancreatic-like ribonuclease is synthesized in the neurons of the rat brain.

Animals

[The clinical and prognostic significance of symptomatic and silent ischemia on the exercise test in patients with a prior myocardial infarct].

The aim of the study was to assess clinical/prognostic significance of exercise-induced ischemia in patients with healed myocardial infarction. From May 1988 to January 1991, 777 consecutive patients underwent a symptom-limited (Bruce protocol) treadmill test at least 1 year after myocardial infarction. Clinical and ergometric data were entered in a prospective way in our data base. The exercise-test was positive in 231 out of 777 patients and 2 different subgroups were retrospectively identified depending on criteria of interruption: 156 patients with painless exercise-ST depression; 75 patients with painful exercise-ST depression. The main results (mean +/- SD) were analyzed with Student t test and chi 2 test. Patients with silent ischemia had longer exercise duration (547 +/- 153 s versus 395 +/- 173 s; p < 0.001) and higher double product (22.98 +/- 0.5 versus 19.71 +/- 0.4; p < 0.001) than symptomatic patients. Ischemic threshold was lower (double product: 17.98 +/- 0.4 versus 21.22 +/- 0.4; p < 0.001 with onset of ST depression at 297 +/- 148 s versus 448 +/- 147 s; p < 0.001) and time to ST normalization was longer (368 +/- 155 s versus 234 +/- 212 s; p < 0.001) in patients with painful ischemia. Patients with angina and ST depression had significantly higher prevalence of downsloping ST depression in the recovery phase (68% versus 37%; p < 0.001) and a higher prevalence of treadmill exercise score indicating high risk (49% versus 3.2%; p < 0.001). The 2 groups when compared with 99 patients with negative test post-AMI were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Molecular cloning of the gene encoding the bovine brain ribonuclease and its expression in different regions of the brain.

In this paper we report the molecular cloning of the gene encoding the bovine brain ribonuclease. The nucleotide sequence determined in this work shows a high degree of identity to the homologous gene encoding the bovine pancreatic ribonuclease. Processing of the primary transcripts of these genes also follows a similar pathway, splicing of the unique intron in the 5' untranslated region occurs at corresponding positions. Expression of the bovine brain ribonuclease gene can be detected both at the transcriptional and translational levels in all the regions of the brain examined.

Amino Acid Sequence

Constitutively elevated levels of ornithine and polyamines in mouse epidermal papillomas.

Epidermal papillomas were induced in CD-1 mice by a single topical application of 7,12-dimethylbenzanthracene (DMBA) followed by twice weekly applications of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in acetone. Control groups consisted of mice treated singly or chronically with acetone or TPA. TPA induced a rapid, yet transient 500- to 1000-fold increase in ornithine decarboxylase (ODC) activity which resulted in a 2- to 8.4-fold elevation of putrescine in both singly or chronically TPA-treated mouse epidermis 4-6 h after its application. After 24 h, levels of spermidine, but not spermine, were also elevated. The ODC and arginase activities in the 11 individual papillomas studied averaged 400- and 26-fold higher respectively than basal levels in epidermis. The activity of ODC in most papillomas, unlike ODC in epidermis, could be stimulated by guanosine 5'-triphosphate (GTP). Putrescine and spermidine levels in papillomas, especially those exhibiting highly GTP-stimulated ODC, were substantially higher compared to either normal or TPA-treated epidermis. Although epidermis contains a relatively high ornithine content, its level is even further elevated in papillomas, in some cases as much as 70-fold. The consequences of the constitutively elevated polyamine levels in papillomas caused by the loss of control over the normally tightly regulated polyamine biosynthetic pathway are not known, but could be important in regulating the balance between proliferation and differentiation in this self-renewing epithelial tissue.

9,10-Dimethyl-1,2-benzanthracene

Parental smoking and asthma in childhood.

The effect of parental smoking on childhood asthma was investigated in which data from 302 asthmatic and 433 healthy children aged 1 to 12 years, were studied. All asthmatic patients received prick tests for common allergens. A significantly higher number of heavy parental smokers was found in asthmatic children under 6 years of age with negative prick tests (P = 0.02). A stepwise logistic regression was performed in order to verify interactions between parental smoking and other variables. It is concluded that parental smoking is an important risk factor for "prick test negative" asthmatic children aged 6 years or less.

Asthma

Genomic footprinting: detection of putative regulatory proteins in the promoter region of the interferon alpha-1 gene in normal human tissues.

Dimethyl sulfate (DMS) genomic footprinting revealed the presence of putative regulatory proteins attached to specific sequences of the promoter region of the interferon (IFN) alpha-1 gene in normal human tissue. The pattern of protein-DNA interactions observed for the human alpha-1 promoter in freshly isolated human spleen cells was identical to that seen in DNA from the B-cell line Namalwa. The protein interactions involving the human IFN alpha-1 promoter spanned a region from positions -38 to -174 relative to the cap site which encompasses that part of the IFN alpha-1 promoter previously shown by deletion analysis to confer virus inducibility on the IFN alpha-1 gene. DNase I footprinting performed on isolated nuclei revealed a pattern of protein-DNA interactions for the promoter region of the IFN alpha-1 gene similar to that obtained with DMS footprinting performed on whole cells, with the appearance or disappearance of only a few additional protected nucleotides outside the region identified by the use of DMS. These results provide the first direct evidence for the presence of proteins bound in vivo to those parts of the IFN alpha-1 promoter between positions -64 and -109 previously shown by deletion analysis to confer virus inducibility on the IFN alpha-1 gene. The pattern of protein-DNA interactions observed for the IFN alpha-1 promoter after virus induction was identical to that seen before induction, in keeping with the finding that many transcriptional activators are present in both induced and uninduced cells.

Base Sequence

[Comparison of vectorcardiography and echocardiography in the evaluation of the site and extent of necrosis in myocardial infarction without Q wave].

In order to improve the evaluation of the site and extent of the necrosis in acute myocardial infarction without Q wave (IMNQ), we used a multiparametric method taking into account the enzymatic values of the total CK, a score derived from Frank's VCG and a kinetic score of the VG segments estimated by echo-2D. The literature data have shown, according to the clinical and anatomical correlations, the frequency of the transmural lesions in the IMNQ cases and, on the contrary, of the lesions limited to the endocardial region and partially transmural in infarctions with new pathological Q waves. The heterogeneousness of the anatomo-pathological data can be explained by the mechanisms of the ischaemia, the site of the coronary occlusion, the presence or not of a spasm, the compensation by the collateral flux and eventually the effects of a treatment by fibrinolytic drugs.

Adult

Long-term treatment after acute myocardial infarction: antiarrhythmic therapy and prophylaxis. Which drug for which patient?

Even if the prognostic significance of ventricular arrhythmias (VA) has been documented in post-AMI CAD, which post-AMI patient showing VA should be treated is still controversial, because no beneficial effects of antiarrhythmic treatment has ever been proved in clinical trials using phenytoin, aprindine, tocainide, mexiletine, and the drugs recently utilized in the CAPS for EVBs. Probably, the rationale for antiarrhythmic therapy is more conclusive in patients with ventricular arrhythmias other than EVBs, and the need for antiarrhythmic drugs should be evaluated in each case, considering other clinical variables of prognostic importance (EF%, extent of coronary lesions, etc.). The type of antiarrhythmic drugs to be used is discussed, considering that, while many traditional antiarrhythmic agents are undoubtedly effective in the treatment of an acute arrhythmia, in the chronic setting, most of the time, a significant reduction in ventricular arrhythmias on Holter monitoring can be proved, without a significant reduction in total mortality. Conversely, we comment on the positive results of some empirical studies showing beneficial effects of antiarrhythmic therapy in high-risk patients reported by Lown's group. Furthermore, it can be stated that patients showing efficacy of antiarrhythmic therapy by both noninvasive and invasive evaluation of antiarrhythmic therapy efficacy had better long-term outcomes. To confirm these data, we report the results of a clinical study of the treatment of complex and frequent EVBs in cardiac patients. A different mortality on follow-up was observed in responders and nonresponders vs. patients not receiving drugs (2.2, 28, and 24%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease

[Paroxysmal tachycardia with long QRS (left branch block type) in a female patient with accessory nodo-ventricular pathway. Role of the anomalous pathway in the electrogenesis of the arrhythmia].

The authors report a case of paroxysmal tachycardia with widened QRS (left bundle branch block morphology), where the electrophysiologic investigation shows an accessory nodo-ventricular pathway and suggests its involvement, as descendent (anterograde) pathway in a circular movement, the ascendant (retrograde) limb of which is the nodo-hisian pathway.

Adult

Structure of the bovine pancreatic ribonuclease gene: the unique intervening sequence in the 5' untranslated region contains a promoter-like element.

Although pancreatic ribonucleases are extensively studied proteins, little information is available on nucleic acids coding for these enzymes. Here, for the first time, the structure of a gene coding for such an enzyme, the well known bovine pancreatic ribonuclease, is reported. The coding region of this gene is devoid of introns, whereas the 5' untranslated sequence of the pancreatic transcript contains an intron of 735 nucleotides. This intervening sequence is endowed with signals (CAAT and TATA boxes) which might act as regulatory elements. The structural organization of this gene suggests that the sequence coding for the bovine pancreatic ribonuclease might be expressed under the control of two different promoters.

Amino Acid Sequence

Expression of opioid genes in bovine seminal vesicles.

In seminal vesicles, the organ producing most of seminal plasma in the bovine species, the pro-opiomelanocortin and the proenkephalin genes are transcribed and translated, and their translation products processed into opioid peptides, which are secreted into the seminal plasma. By using a micro-organ preparation of seminal vesicles we found that, after 20 h of incubation with labelled methionine, a multiplicity of opioids was produced. Among these, [Met]enkephalin and beta-endorphin were positively identified, whereas in the newly formed secretion only [Met]enkephalin was detected. This may be correlated to the finding that the concentration of beta-endorphin in an extract of seminal plasma was one order of magnitude lower than that of [Leu]enkephalin and [Met]enkephalin. These findings expand the picture of the presence of opioid peptides in the male reproductive tract, indicating that they should have a role(s) in the physiology of reproduction, not only in the hypothalamus-pituitary-gonadal axis, determining the reproductive potential, but also in the so-termed sex accessory glands, determining the actual events leading to reproduction. To our knowledge this is also the first case studied of opioid peptides produced as exocrine hormones.

Animals