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Biomedical subjects

G Parenti

Publications and source records attributed to G Parenti.

At least 73 records · Page 4Linked to original sources
PubMed1995

Ruptured cerebral aneurysms operated on with only MRA. Reports of two cases.

Two cases of ruptured aneurysms of anterior communicating artery were reported. The aneuryms were showed only by means of MR angiography and operated on without conventional angiography, since patients' allergy to drugs and medium contrast. The MRA showed precisely the sites of the aneurysm and the directions of the sac, but underestimated the size of the sac. In spite of the lack of angiograms induced a great caution during the dissection of the aneurysm and made necessary a larger operative field, anyway clipping of the aneurysm's neck was performed without great difficulties.

Adult↗
PubMed1995

Spinal cavernous angioma producing subarachnoid hemorrhage. Case report.

A case of subarachnoid hemorrhage due to intramedullary cavernous angioma at the T9 level is presented. Literature dealing with subarachnoid hemorrhage due to intraspinal lesions is reviewed. The majority of cases of spinal subarachnoid hemorrhage are due to arteriovenous malformations, whereas bleeding by cavernous angioma is extremely rare. The subarachnoid hemorrhage is rare event (1.8%) in our series too. The clinical presentation of severe back pain with radicular component associated with signs of meningism (Fincher's syndrome) led us to carry out magnetic resonance imaging. This gave accurate diagnosis for surgical treatment. Laminectomy at T9-T10 level and total microsurgical removal of the vascular malformation were performed with total functional recovery.

Adult↗
PubMed1995

[Pulmonary carcinoma and solitary intracranial metastasis: results of the combined surgical treatment].

Previous reports have shown the utility of combined lung and brain surgery in patients with a primary non small cell lung cancer (-NSCLC) and solitary brain metastasis. This paper reports our recent data with the aim to rationalize the indication of this surgical approach. Over a period of eighteen years (1975-1992), 50 patients with NSCLC and solitary brain metastasis underwent combined lung and brain surgery. Fifteen of these patients had a synchronous presentation while the remaining 35 had a metachronous presentation of lung cancer and single brain metastasis. There were no operative deaths and complete remission of neurological symptoms was obtained in 46 patients (92%). Actuarial overall five year survival was 16% with a median survival of 21 months. Age, gender, histology, T status, size and site of NSCLC, site and location of brain metastasis and the association with adjuvant therapy did not significantly affect survival. The variables that were associated with a significantly prolonged survival were type of lung surgery, N status and interval between the two operations. Patients with synchronous presentation had a five-year survival of 6.6%. By contrast the actuarial five-year survival of those patients with the diagnosis of brain metastasis after the removal of NSCLC was 19%. In this subset of patients those with N0 status and a median interval between lung and brain surgery longer than 14.5 months had a significantly longer survival. We may conclude that combined lung and brain surgery is recommended both for relieving neurological symptoms and for prolonging survival. This is particularly true in those patients with limited loco-regional involvement and a late single brain metastasis.

Adult↗
PubMed1995

[111In-DTPA-D-Phe]-octreotide scintigraphy in functioning and non-functioning pituitary adenomas.

Scintigraphy with [111In-DTPA-D-Phe]-octreotide is a recently developed technique for imaging somatostatin receptors in many neuroendocrine tumors. A good correlation between high [111In-DTPA-D-Phe]-octreotide uptake and the response to octreotide therapy has been proved in TSH- and GH-secreting pituitary adenomas, while few and conflicting scintigraphic data on somatostatin receptors in non-functioning tumors have been reported in the literature. The present study presents the results obtained with [111In-DTPA-D-Phe]-octreotide scintigraphy in thirteen patients with GH-secreting pituitary adenoma, four patients with inappropriate TSH-secretion and twelve patients with non-functioning pituitary adenoma. Twelve out of the 13 patients with GH-secreting pituitary adenomas had a positive scan; moreover, in 5/6 patients with a GH-secreting microadenoma (tumor size range 5-8 mm) a positive scan was found. Two TSH-secreting macroadenomas had a positive scan while a negative scan was obtained for a TSH-secreting pituitary microadenoma and in a patient with non-neoplastic, inappropriate secretion of TSH. Finally, only 2/12 patients with non-functioning pituitary adenoma showed a positive scan. In conclusion, [111In-DTPA-D-Phe]-octreotide scintigraphy is a useful tool to confirm the presence of somatostatin receptors in selected patients with GH- and TSH-secreting pituitary adenoma. The role of [111In-DTPA-D-Phe]-octreotide scintigraphy in non-functioning pituitary tumors remains to be established, but it could be useful for octreotide treatment in patients who refuse surgery or who are poor surgical candidates.

Adenoma↗
PubMed1994

Bilateral traumatic abducens nerve palsy. Case report.

Bilateral traumatic abducens nerve palsy after head injury is a rare event. We present a case associated with skull fractures and intracranial hematoma, with complete recovery of abducens nerve palsy after six months. The mechanism of the lesion, the clinical conditions and the radiological findings are presented.

Abducens Nerve↗
PubMed1993

Spontaneous regression of intracranial arteriovenous malformation.

Spontaneous regression of an arteriovenous malformation is rare. When complete or partial regression occurs, an associated factor is usually involved, such as intracranial hemorrhage, surgery, radiation therapy, or a new neurological deficit. Another case in which the resolution was totally spontaneous is presented here. We discuss the importance of transcranial doppler revealing the hemodynamic changes in the cerebral arteries in the presence of an AVM and when the latter is thrombosed. Several mechanisms for regression are considered, and we focus on the dissection of the afferent vessel, pointing out the role of such an event in the natural history of AVM.

Adult↗
PubMed1993

In vivo radiofrequency-based ultrasonic tissue characterization of the atherosclerotic plaque.

BACKGROUND AND PURPOSE: The ultrasonic image can offer unique information on the composition of atherosclerotic plaque, ie, the relative content of lipids, fibrous tissue, and calcific deposits. To date, however, the echographic assessment of plaque structure is based on a subjective, qualitative evaluation of the bidimensional images. We evaluated the feasibility and accuracy of assessing, in vivo, the acoustic properties of arterial carotid plaques by means of a suitably modified echographic apparatus allowing direct access to the radiofrequency signal. METHODS: In 15 patients undergoing carotid thromboendarterectomy, the ultrasonic findings in 70 discrete sites (within the plaque, n = 54; normal sites, n = 11; or intraluminal thrombi, n = 5) were correlated with the histological analysis (hematoxylin-eosin and Mallory trichrome stains) independently performed on the arterial samples. The pathological examination was carried out at a similar level of the insonation; the sites analyzed within the plaque were chosen because of their uniform echoic characteristics. In each ultrasonic region of interest selected from the echographic image, the integrated amplitude of the rectified radiofrequency signal was measured as the integrated backscatter index. RESULTS: The intimal-medial layer of normal carotid wall (n = 11) exhibited values of -32.5 +/- 9.4 dB. The integrated backscatter index in fatty sites (n = 11, -40.3 +/- 5.4 dB) differed from that of fibrous (n = 12, -23.8 +/- 5.0 dB) and calcified (n = 26, -11.5 +/- 5.2 dB, P < .01 for all intergroup differences) sites. Intraluminal thrombotic sites (n = 5, -42 +/- 5.1 dB, P < .01) differed from fibrous and calcified subsets (P < .01) but overlapped (P = NS) with fatty sites. Histological sampling also showed two sites of intraplaque hemorrhage that exhibited very low backscatter values (-53 and -58 dB) and three fibrofatty sites showing backscatter values (-28, -28, and -32 dB) intermediate between the fibrous and the fatty subsets. CONCLUSIONS: Quantitative analysis of integrated backscatter of the arterial wall is feasible in humans and provides an operator-independent assessment of plaque echoic structure. In particular, integrated backscatter is effective in distinguishing lipidic, fibrotic, and calcific components in human atherosclerotic plaques.

Arteriosclerosis↗
PubMed1993

Primary cauda equina tumors.

During the last seven years (1985-91) 28 primary tumours in the cauda among 104 intraspinal tumors were observed. The largest group (71%) comprised ependymomas and neurinomas. The rest included 5 lipomas, 2 astrocytomas and 1 epidermoid. Low-back pain without or with sciatic or crural irradiation was the most common initial symptom. The length of symptomatology is generally measured in months, because pain is erroneously referred to discal pathology for long time. The X-ray standard test and the CT scan have been of modest utility in the diagnosis of these lesions, but however they have been necessary for diagnostic screening. The MNR, a bloodness test, showed an important diagnostic value for the identification of these tumors; it is also useful in follow-up to exclude recurrence. The lipoma's and ependymoma's surgery, although performed by microsurgical techniques, showed great problems. Total removal of the ependymomas assured no recurrence at the follow-up. Sphincter disturbances were frequent after the operation, but they disappeared after some months. In most patients with lipomas the resection was partial, but at follow-up they were symptomless. Neurinomas' surgery presented less technical difficulties and the postoperative course was more favorable. Astrocytomas underwent to radiotherapy but their prognosis is not favorable.

Adolescent↗
PubMed1992

Phenobarbital in the prophylaxis of late posttraumatic seizures.

390 patients with severe head injuries were treated with phenobarbital (PB) orally for a period of 12 months in order to determine whether this drug could reduce the incidence of posttraumatic epilepsy (PTE). An intramuscular PB dose of 2.5-3 mg/kg body weight per day was administered within 24 hours after the trauma; after 5 days, or longer if the coma persisted, the drug was administered orally. Maintenance dosage adjustments, when necessary, were based on serial plasma concentrations of the drug, sustained at between 5 and 30 micrograms/ml. 293 patients completed the study. 66% of these presented one risk factor, while 34% presented two or more. 6 patients (2.04%) had at least one seizure during the twelve months. Plasma drug levels at the time of the seizure, with one exception of 15 micrograms/ml, ranged from 20 to 28 micrograms/ml. The results of the study indicate that PB administered during the first twelve months after the trauma, even at relatively low doses, can have a prophylactic effect on PTE.

Adolescent↗
PubMed1992

Assessment of intracranial circle after carotid endarterectomy.

To evaluate haemodynamic effects of carotid endarterectomy on cerebral circulation, transcranial Doppler sonography was performed on 69 patients operated for unilateral carotid stenosis greater than 70%. Pre- and post-operative Vm and PI on bilateral middle-cerebral arteries, Vm PI and flow direction on ipsilateral anterior cerebral artery and Vm on basilar artery were evaluated. All patients presented more or less evident preoperative haemodynamic alterations of cerebral circulation and after surgery showed a normal distribution of cerebral blood supply.

Brain Ischemia↗
PubMed1992

Clinical variability of cardio-facio-cutaneous syndrome: report of two additional cases.

We describe two new cases of cardio-facio-cutaneous (CFC) syndrome, and underline the clinical variability of the CFC phenotype in our two patients presenting with border-line psychomotor development. The first patient showed some additional clinical manifestations, such as cryptorchidism and scoliosis, and the second one had atypical skin lesions.

Cryptorchidism↗
PubMed1992

Intracranical aneurysm and cerebral embolism.

Embolism from the aneurysmal sac is a rare but possible manifestation of intracranial aneurysm; thrombus formation is probably related to the combined action of turbulent flow and a 'stagnant zone'. Three cases are presented: 2 with giant aneurysms (1 internal carotid and 1 sylvian) and 1 with a large aneurysm of the middle cerebral artery. In the latter, surgical treatment was performed, while in the others a conservative therapy was preferred. No ischemic manifestations were observed in the follow-up.

Aged↗
PubMed1992

Identification of point mutations in the steroid sulfatase gene of three patients with X-linked ichthyosis.

X-linked ichthyosis (XLI) is an inborn error of metabolism caused by steroid sulfatase (STS) deficiency. In more than 80% of XLI patients the enzyme deficiency is due to large deletions involving the entire STS gene and flanking sequences. However, some patients with the classical XLI phenotype and complete STS deficiency do not show any detectable deletions by Southern blot analysis using full-length STS cDNA as a probe. We have studied five unrelated patients who are such "nondeletion" mutants. Western blot analysis using anti-STS antibodies was performed on patients' fibroblast extracts and revealed absence of cross-reacting material. First-strand cDNA synthesis by reverse transcription from patients' RNA isolated from cultured fibroblasts and PCR amplification of overlapping segments of the entire STS polypeptide coding region were performed. Three point mutations were identified by chemical mismatch cleavage, sequenced by dideoxynucleotide chain-termination sequencing and confirmed by allele-specific oligonucleotide hybridization of the patients' genomic DNA. The mutations resulted in the substitution of a tryptophan for an arginine at codon 1319, changing a hydrophobic to a basic hydrophilic amino acid, the substitution of a cysteine for a tyrosine at codon 1542, potentially losing a disulfide bond, and the substitution of a serine for a leucine at codon 1237. These are the first point mutations to be documented in the STS gene and may allow insight into functionally important domains of the protein.

Amino Acids↗
PubMed1991

Antibodies against the antibiotics: an overview.

Antibiotics are small molecules used in the treatment of diseases due to pathogenic microorganisms such as bacteria, viruses, fungi. They have different mechanisms of actions and by exploiting their selective toxicity on the infecting microorganism they do not necessarily damage the host cell. Assay for antibiotic concentrations in blood, urine and other body fluids is motivated primarily in conjunction with antibiotic pharmacology and pharmacokinetics to: a) establish the therapeutic levels of the drug; b) monitor antibiotics with narrow toxic/therapeutic ratios; c) detect accumulation of the antibiotic metabolites. The assay used to measure a wide variety of antibiotics is based on the intrinsic capability of these molecules to inhibit the growth of a suitable microorganism. In the last few years other types of tests, e.g., enzyme immunoassays, have been developed based on polyclonal and monoclonal antibodies. Antibodies against non antigenic molecules like antibiotics can be raised by using as antigen the antibiotic (hapten), conjugated with a carrier protein. Polyclonal antibodies containing mixed populations of antibodies (against different antigenic sites of the hapten, the carrier and the site of conjunction between the hapten and the carrier) are largely used to set up enzyme immunoassays for antibiotics. Monoclonal antibodies by recognizing one antigenic site of the hapten have a better specificity but sometimes less affinity than polyclonals. In the case of antibiotics, to raise monoclonal antibodies with good affinity it is important to use targeted immunization and screening strategies that utilize the antibiotic conjugated in different ways to different carriers.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1990

Lysosomal tartrate sensitive acid phosphatase deficiency in cells which contain lysosomal "high uptake forms".

The catalytic and immunological properties of acid phosphatases (EC 3.1.3.2.) in different tissues were studied. It was demonstrated that high uptake forms of lysosomal enzymes like beta-galactosidase isolated from human platelets and bovine testis are mature enzymes, which have not lost their mannose-6phosphate marker. The results presented indicate that this phenomenon is related to a low activity or the complete absence of the lysosomal tartrate sensitive acid phosphatase activity in the tissues concerned.

Acid Phosphatase↗
PubMed1990

Detection of early abnormalities in the mucopolysaccharidoses by the use of visual and brainstem auditory evoked potentials.

Flash visual evoked potentials (FVEPs) and brainstem auditory evoked potentials (BAEPs) were performed in 13 children (aged 3-17 years) affected by mucopolysaccharidoses (MPSs). FVEPs and BAEPs were abnormal in 6 and 9 patients, respectively. The presence of these abnormalities in most neurologically normal patients suggests that electrophysiological techniques provide a useful tool for detecting early abnormalities.

Adolescent↗