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Biomedical subjects

A Rinaldi

Publications and source records attributed to A Rinaldi.

At least 37 records · Page 2Linked to original sources
PubMed2000

Cloning of PC3B, a novel member of the PC3/BTG/TOB family of growth inhibitory genes, highly expressed in the olfactory epithelium.

We identified in the EST database murine and human sequences similar, but not identical, to the members of the PC3/BTG/TOB family of cell cycle inhibitors. A conserved domain (aa 50-68) of the PC3 protein, the prototype member of the family, was used as a query. That domain has been shown by us to be necessary for the antiproliferative activity of PC3. A murine EST clone and a highly homologous human EST clone, containing the entire ORF, were chosen for sequencing. Comparison to databases and a phylogenetic tree analysis indicated that these EST clones are the mouse and human homologues of a gene that represents a novel member of the PC3/BTG/TOB family. This gene, named PC3B, is endowed with marked antiproliferative activity, being able to induce G(1) arrest, and is highly expressed in testis, in oocyte, and in preimplantation embryos. Analysis of its expression during murine development indicated a specific localization in the olfactory epithelium at midgestation, suggesting that PC3B might be involved in the differentiation of this neuronal structure. Human PC3B mapped to chromosome 11q23, as indicated by radiation hybrid analysis.

Amino Acid Sequence↗
PubMed2000

Long-term transgene expression in mice infected with a herpes simplex virus type 1 mutant severely impaired for immediate-early gene expression.

The role of viral immediate-early (IE) gene expression in herpes simplex virus type 1 (HSV-1) latency was investigated. The HSV-1 multiple mutant in1312, defective for the expression of the virion transactivator VP16 and the IE proteins ICP0 and ICP4, was used as the parent for these studies. The coding sequences of the Escherichia coli lacZ gene, preceded by the encephalomyocarditis virus internal ribosome entry site, were inserted into the region of in1312 that encodes the latency-associated transcripts (LATs) such that transcription of the transgene was controlled by the LAT promoter. This insert has previously been shown to direct long-term latent-phase expression of beta-galactosidase in a wild-type HSV-1 genome (R. H. Lachmann and S. Efstathiou, J. Virol. 71, 3197-3207, 1997). The resulting recombinant, in1388, was apathogenic after inoculation into mice via the footpad and did not detectably replicate in dorsal root ganglia (DRG) or footpads. Mutant in1388 established latency in DRG, and beta-galactosidase was expressed in increasing numbers of neurons over the first 25 days of infection. During latency, more than 1% of neurons in ganglia that innervate the footpad expressed beta-galactosidase, with the number of positive cells remaining constant for at least 5 months. Rescue of the VP16, ICP0, or ICP4 mutations of in1388 did not affect the number of beta-galactosidase-expressing neurons detected during latency. The results demonstrate that HSV-1 mutants severely impaired for IE gene expression are capable of establishing latency and efficiently expressing a foreign gene product under control of the LAT promoter.

Animals↗
PubMed2000

Acoustic intrameatal meningiomas.

BACKGROUND: The sporadic finding of an acoustic intrameatal meningioma stimulated the authors to the present study. An analysis of the cases previously reported in the literature aimed to outline a preliminary account about biological, radiological and surgical specific hallmarks of these tumours. METHODS: Eight previous cases of meningiomas, meeting the prerequisite of origin and situation within the internal acoustic canal, have been discovered in the known literature since 1975. A further case was recently observed in our experience. The cases in the series showed no sex prevalence and in most of them the age of incidence was comprised between the fifth and sixth decade of life. Hearing loss was the prevalent symptom, lasting 1 month to 7 years before presentation. Myelocisternography, myelo-CT or high resolution CT/MR revealed no specific radiological features to distinguish small intrameatal meningiomas from the more frequently occurring vestibular schwannomas, while CT scan with bone algorithm could point out valuable indirect details for differential diagnosis. Various surgical approaches, i.e. middle fossa, translabyrinthine and retromastoid, were utilized by the different authors. RESULTS: Basing on apparent individual surgical preference, one of three different surgical routes (translabyrinthine, middle fossa, retromastoid) was chosen for 10 procedures in 9 patients. In all, except two cases the impression at surgery was of complete tumour removal. CONCLUSIONS: The possibility for meningiomas to recur and invade the surrounding bone requires a differential diagnosis from vestibular schwannomas. In the absence of intrinsic distinctive signs, radiological evaluation of peritumoral bone alterations could help diagnosis. Although the various surgical routes have often proved effective, temporal bone invasion justifies more extensive approach even in small tumours.

Adolescent↗
PubMed2000

Cranio-orbital missile wound and bullet migration. Case report.

An unusual case of craniocerebral missile injury, with orbital roof perforation and spontaneous bullet migration into the maxillary sinus, is reported. Emergency treatment consisted in wide craniectomy around the bullet entry point, blood and foreign bodies debridement. Subsequent procedures were necessary for abscess evacuation, transmaxillary bullet removal and later cranial vault reconstruction. Challenging aspects were the treatment of the infectious complications, following cerebrospinal fluid fistula through the wound, and the onset of post-traumatic epilepsy, scarcely responsive to common antiepileptic drugs. The treatment of the abscess by combined systemic and intracavitary antibiotic therapy and of the chronic seizures by progressive adjustment with new protocols of antiepileptic drugs under EEG and brain mapping revealed successful.

Adult↗
PubMed2000

[Telemedicine in neonatal emergencies].

UNLABELLED: Telemedicine is the transmission of medical notices and images among remote sites, that uses adequate audio-video systems. OBJECTIVE: To increase the quality and the amount of medical informations, avoiding unnecessary carriages. Among main fields of interest in Telemedicine, monitoring of cardiovascular parameters and medical emergency represent situations that need to be promptly and appropriately approached. In such a similar conditions, a preliminary transmission to III level Health Institutions of informations as Electrocardiograms or even Echocardiograms may play an essential role in the diagnosis, prognosis and treatment of emergent cardiovascular disease. METHODS: Since March 1998, an Audio-Video PC-based system that uses integrated services digital network (ISDN) at a bandwith of 384 Kbps, was installed at Pediatric Cardiac Surgery Department of Giovanni XXIII Hospital, Bari, Italy. On July 1999, thanks to Research Funds of the Health Ministry of Italy, similar audio-video systems that use ISDN were installed in the main pediatric institutions of provinces of Puglia and linked in a wide area network. RESULTS: We report the experience of Telemedicine of a Department of Pediatric Cardiology and Cardiac Surgery, and we try to analyze its impact on improvement of quality of care, once employed in provincial field.

Emergencies↗
PubMed1999

Properties of the adenovirus type 40 E1B promoter that contribute to its low transcriptional activity.

The adenovirus type 5 (Ad5) E1B promoter contains two elements essential for maximal activity, a TATA box and a GC box. The enteric adenovirus type 40 (Ad40) E1B promoter has a TATA box sequence identical to that of Ad5 and a GC box that fits the Sp1 binding site consensus. Nevertheless, Ad40 E1B RNA synthesis is severely impaired in HeLa cells, attributable in part at least to the weak transactivating activity of Ad40 E1A. However, the responsiveness of Ad40 early promoters to E1A transactivation has not been directly demonstrated. Using a transient expression assay with a chloramphenicol acetyl transferase (CAT) reporter gene, the Ad40 E1B promoter was very poorly transactivated by E1A of both Ad40 and Ad5 and showed only a limited response to the promiscuous varicella zoster virus transactivator p140. Construction of Ad5 recombinant viruses expressing the CAT gene under the control of the Ad5 or Ad40 E1B promoter allowed detection and measurement of expression from the Ad40 E1B promoter in a well-defined background and showed that overall activity is some 100-fold lower than for the Ad5 E1B promoter. Deletion analysis revealed that sequences upstream of the Sp1 binding site down-modulated Ad40 E1B promoter responsiveness, and two protein binding sites, identified by DNase footprinting and gel retardation assay, may be implicated in this effect. Gel shift analysis also showed that the Ad40 Sp1 binding site had a reduced affinity for Sp1 protein, relative to the Ad5 site, and that the context as well as the core sequence had an influence on Sp1 recognition.

Adenovirus E1B Proteins↗
PubMed1999

A non-cytotoxic herpes simplex virus vector which expresses Cre recombinase directs efficient site specific recombination.

The coding sequences for the bacteriophage P1 recombinase Cre were cloned into the genome of a herpes simplex virus type 1 (HSV-1) mutant which is severely impaired for the synthesis of immediate early (IE) proteins. The resulting recombinant, virus in1372, expressed functional Cre which mediated the excision in trans of loxP-flanked sequences located in the HSV-1 genome, both in tissue culture cells and in vivo in mouse sensory neurons. Infection with in1372 also resulted in recombination, at high efficiency, between loxP sequences in the cellular genome without causing detectable cytotoxicity. Mutant in1372 is a versatile vector for the delivery of Cre in tissue culture and in vivo.

Animals↗
PubMed1999

Activation of herpesvirus gene expression by the human cytomegalovirus protein pp71.

The activation of gene expression by the human cytomegalovirus (HCMV) particle was investigated. The HCMV major immediate-early (IE) promoter was cloned upstream of the Escherichia coli lacZ coding sequences, and the resulting cassette was introduced into the genome of a herpes simplex virus type 1 (HSV-1) mutant lacking functional VP16. Upon infection with the HSV-1 recombinant in the presence of cycloheximide, to block de novo protein synthesis, expression of lacZ-specific transcripts was increased by fivefold when HCMV was included in the inoculum. Accumulation of HSV-1 IE RNAs was also stimulated by coinfection with HCMV, as was expression of the adenovirus 5 VAI transcript when the VAI gene was cloned into the HSV-1 genome. Coinfection with HCMV did not alter mRNA stability or uncoating of the HSV-1 genome. The coding sequences for the HCMV phosphoprotein pp71, controlled by the HCMV IE promoter, were cloned into an HSV-1 recombinant impaired for the production of the three major transactivators (VP16, ICP0, and ICP4) to yield a recombinant (in1324) which expressed pp71 but did not cause significant cytotoxicity. Infection with in1324 resulted in stimulation of HCMV IE, HSV-1 IE, and VAI expression, demonstrating that pp71 is responsible for the effects we observed when using the entire HCMV particle. Therefore, HCMV pp71 exhibits novel properties in its ability to stimulate gene expression from a range of promoters present in a herpesvirus genome.

Cell Line↗
PubMed1999

Conservative management of C5-C6 fracture-luxation in the elderly. Case report.

The case of a 86-year-old female victim of cervical trauma with C5-C6 fracture-luxation and bilateral locked facets is hereinafter described. The case was reputed representative of the complexity in deciding between conservative and surgical treatment in spine surgery. Conservative management would have been dictated by the additional risks linked to the age of the patient, whereas the surgical treatment would have been favored by the easy access to the anterior cervical spine for reduction and fixation. On the way to plan the definitive treatment, the patient died by pulmonary embolism. The controversial aspects and the indication to anticoagulant therapy in spinal surgery, frequently faced in the treatment of spine trauma in patients of this age group, are discussed in this case report.

Aged↗
PubMed1998

Effect of 3-hydroxyanthranilic acid on mushroom tyrosinase activity.

Tyrosinase is a copper containing protein which catalyzes the hydroxylation of monophenols and the oxidation of diphenols to o-quinones. The monophenolase activity of tyrosinase is characterized by a typical lag time. In this paper the influence of 3-hydroxyanthranilic acid on monophenolase activity of tyrosinase is reported. 3-Hydroxyanthranilic acid reduced the lag time of tyrosinase when the enzyme acted on N-acetyl-L-tyrosine and on 4-tert-butylphenol. In the presence of 3-hydroxyanthranilic acid, the reaction product 4-tert-butyl-o-benzoquinone, derived from 4-tert-butylphenol oxidation, was formed at a higher rate than in its absence. The results reported in this paper indicate that 3-hydroxyanthranilic acid could affect the enzymic activity of mushroom tyrosinase probably by acting as a diphenol substrate. A K(m) value of 0.78 mM was calculated for 3-hydroxyanthranilic acid as substrate. When tyrosinase acted on 4-tert-butylphenol, K(m) for 3-hydroxyanthranilic acid as a cofactor was estimated to be 37.5 microM. No effect was observed on the diphenolase activity of the enzyme acting on 4-tert-butylcatechol in the presence of 3-hydroxyanthranilic acid.

3-Hydroxyanthranilic Acid↗
PubMed1998

Biosynthesis of the topaquinone cofactor in copper amine oxidases--evidence from model studies.

Copper amine oxidases utilize 2,4,5-trihydroxyphenylalanine quinone (topaquinone) as a cofactor in enzymatic catalysis. This cofactor is formed from a tyrosine residue through a self-catalytic mechanism with the participation of the copper ion at the active site. Although pathways have been postulated for topaquinone biogenesis, portions of this scheme are still unclear. We utilized 4-tert-butyl-derived models for the putative intermediates of topaquinone generation and studied the effect of Cu(II) and Zn(II) ions on each autoxidative step from dopa- to topaquinone-like compounds at physiological pH (7.4). Several polyvinyl-alcohol-based soluble resins bearing mono- and di-hydroxyphenolic moieties were also prepared, and their tendency to give hydroxyquinonic structures when incubated at alkaline pH values was investigated. Our results confirm (although indirectly) the formation of dopa and dopaquinone during topaquinone biosynthesis. Moreover, we collected evidence that, following the formation of dopa, the role of the active-site copper ion in topaquinone biogenesis would be limited to the catalysis of the two subsequent quinonization steps (i.e. from dopa to dopaquinone and from topa to topaquinone), thus disfavoring the possibility of a direct intervention of the metal ion in the hydroxylation of dopaquinone. In particular, Cu(II) was shown to influence deeply the autoxidation of 1,2,5-trihydroxy-4-tert-butylbenzene, used as model of topa, both increasing the reaction rate and changing its mechanism. The mechanistic implications of these findings for the biogenesis of topaquinone and its analogs at the active site of various amine oxidases are discussed.

Aldehydes↗
PubMed1998

Stereotactic-guided microsurgical removal of lesions without cortical appearance planned by three-dimensional CT reconstruction: limits and advantages of the frame-based technique.

Intraoperative positioning still constitutes a basic problem in the microsurgical removal of intracerebral lesions, either deep-seated or without cortical appearance. We treated different types of lesions (cavernous angiomas, intraventricular tumors, gliomas, and metastases), by combining stereotactic targeting with the standard microsurgical technique. The dedicated software for the three-dimensional reconstruction of stereotactic CT images allowed us to determine the least traumatic surgical trajectory and the exact location of the lesion intraoperatively, with minimum manipulation of healthy cerebral tissue. We believe that the main indication for this technique is the removal of small, encapsulated or well-defined lesions without cortical appearance or in critical areas, while a direct inspection of the area is still essential in order to evaluate surgical removal in the case of infiltrating tumors.

Adolescent↗
PubMed1998

Herpes simplex virus type 1 immediate early gene expression is stimulated by inhibition of protein synthesis.

Herpes simplex virus type 1 (HSV-1) transcription can be arrested at the immediate early (IE) stage by continuous treatment of cells with inhibitors of protein synthesis, usually cycloheximide, from the time of infection. We have analysed the effect of cycloheximide on IE gene expression with HSV-1 mutants deficient in the production of functional levels of the three major transactivators, the virion protein (VP16) and two IE proteins (ICP0 and ICP4). Expression from the HSV-1 IE promoters that control synthesis of ICP0 and ICP27 was, unexpectedly, stimulated by inhibition of protein synthesis. The effect was observed for the ICP0 promoter in its normal genome location and also when cloned upstream of the Escherichia coli lacZ coding sequences and inserted into the viral thymidine kinase locus. Expression from the human cytomegalovirus major IE promoter, when cloned into the genome of HSV-1 mutants, was also increased by inhibition of protein synthesis. Cycloheximide did not affect the intracellular stability of lacZ-specific RNA, suggesting that the response represented an increase in mRNA production. Activation of the ICP0 promoter was observed when protein synthesis was blocked by alternative agents. Since inhibitors of protein synthesis are known to activate cellular signal transduction pathways, our findings demonstrate new mechanisms for the regulation of HSV-1 IE gene expression which may be important during latency and reactivation. The results also highlight previously unrecognized difficulties in analysing the intrinsic activities of promoters when cloned into the HSV-1 genome.

Animals↗
PubMed1996

Premutation for the Martin-Bell syndrome analyzed in a large Sardinian family: III. Molecular analysis with the StB12.3 probe.

This report complements a series of clinical, cytogenetical, and psychological studies previously reported on a large Sardinian pedigree segregating for premutations and full mutations associated with the Martin-Bell syndrome (MBS). Using the StB12.3 probe, we report now the molecular classification of all of the critical members of the pedigree. These molecular findings are evaluated against the variable phenotypic manifestations of the disease in the course of a six-generation segregation of an MBS premutation allegedly present in a common female progenitor of 14 MBS male patients and 9 female MBS heterozygotes seen in the last two generations. The nature and stepwise progression of MBS-premutations toward the fully manifested Martin-Bell syndrome and the possibility of reverse mutational events toward the normal allele are discussed with respect to the application of the presently available diagnostic tools in genetic counselling.

B-Lymphocytes↗
PubMed1996

Further linkage evidence for localization of mutational sites for nonsyndromic types of X-linked mental retardation at the pericentromeric region.

We used several microsatellite markers scattered along the X chromosome to search for linkage relationships in a large Sardinian pedigree segregating for nonspecific X-linked mental retardation (MRX). Markers DXS573 and AR, located at chromosomal subregions Xp11.4-p11.22 and Xq11.2-q12, respectively, were found to segregate in full concordance with the disease, leading to a LOD score of 4.21 at zero recombination value. Recombination with the disease was found with markers MAOB and DXS454 located at Xp11.4-p11.3 and Xq21.1-q22, respectively; accordingly, markers distal to Xp11.4 and Xq22 also segregated independently of the disease. These findings provide strong linkage evidence in favor of the localization of one MRX mutational site in the pericentromeric region of the human X chromosome, justifying the assignment of a new symbol (MRX26) to our pedigree. Finally, on the basis of the recombinational events observed in the Xq21-q22 region, we have been able to refine the assignment of marker DXS456 to Xq21.33-q22.

Chromosome Mapping↗
PubMed1996

Dopaquinone hydroxylation through topaquinone cofactor in copper amine oxidases: a simplified chemical model.

A simple model, 4-tert-butyl-1,2-benzoquinone, was chosen to study the hydroxylation step of the tyrosine-derived Dopaquinone residue at the active site of copper amine oxidases in the self-catalytic generation of the Topaquinone cofactor. This hydroxylation step was studied both in the presence and absence of free copper(II), and was found to be dependent on pH value but not on the presence of metal ions. It is therefore proposed that, hydroxide ion and not water should be the true reactive species in this key biosynthetic step of the Topaquinone cofactor, and that the active site Cu2+ is implied, at this point of cofactor biosynthesis, in the quinonisation of Topa rather than in the hydroxylation of Dopaquinone.

Amine Oxidase (Copper-Containing)↗
PubMed1996

Detection of Chlamydia pneumoniae but not Helicobacter pylori in atherosclerotic plaques of aortic aneurysms.

Recent reports suggest an association between Chlamydia pneumoniae and Helicobacter pylori bacteria and atherosclerosis. We studied 51 patients (mean age, 68.3 years) who underwent abdominal aortic aneurysm surgery. For each patient we performed a microimmunofluorescence test for immunoglobulin G (IgG), IgA, and IgM antibodies to C. pneumoniae specific antigen (TW-183). Anti-H. pylori antibodies were determined by means of an EIA-G test. Each aortic aneurysm surgical specimen was sampled into multiple sections of 0.3 cm2 each and frozen at -20 degrees C. Two samples of each aneurysm were used for a nested PCR with two sets of C. pneumoniae and two sets of H. pylori specific primers. Specimens were treated with a solution containing 20 mM Tris-HCl, Tween 20-Nonidet P-40 (0.5% [vol/vol] each), and 100 micrograms of proteinase K per ml and incubated at 60 degrees C for 1 h and at 98 degrees C for 10 min. DNA was extracted twice with phenol-chloroform-isoamylic alcohol and precipitated with sodium acetate-ethanol by standard methods. Forty-one patients were seropositive for C. pneumoniae with past-infection patterns in 32 patients (16 < or = IgG < 512; 32 < or = IgA < 256) and high antibody titers in 9 patients (IgG > or = 512). In 26 of 51 patients, C. pneumoniae DNA was detected in aortic aneurysm plaque specimens. Of these patients, 23 had a serologic past-infection pattern, 2 had an acute reinfection pattern, and 1 was seronegative. Forty-seven of 51 patients were seropositive for H. pylori. In all cases PCR showed no evidence of H. pylori presence in plaque specimens. This study provides data on a possible C. pneumoniae involvement in the pathogenesis of aortic aneurysm and additional evidence for an association between this agent and atherosclerosis. Conversely, notwithstanding a high H. pylori seroprevalence observed, our results tend to rule out the possibility of a direct involvement of H. pylori in atherosclerosis.

Aged↗