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Biomedical subjects

G Parenti

Publications and source records attributed to G Parenti.

At least 55 records · Page 3Linked to original sources
PubMed1997

Combined transcranial Doppler and electrophysiologic monitoring for carotid endarterectomy.

The results of carotid endarterectomy can be improved by reducing the perioperative embolic and hemodynamic risks. Electrophysiologic monitoring, although reliable, cannot provide full information. In this study, we report on the combined use of transcranial Doppler (TCD) and electrophysiologic monitoring in 153 patients undergoing 166 carotid endarterectomy procedures. TCD monitoring confirmed the low incidence of intolerance to cross-clamp (1.8%), showing a good correlation with electrophysiologic monitoring. In addition, it frequently showed embolic signals immediately after clamp release, but never during carotid dissection or in the final operative phases. Furthermore, TCD allowed the detection of hyperperfusional flow patterns in four cases, making immediate and aggressive control of arterial pressure possible.

Aged↗
PubMed1997

Carotid plaque features on angiography and asymptomatic cerebral microembolism.

We studied 110 carotid arteries of 55 patients with unilateral or bilateral carotid stenosis diagnosed with selective angiography, by using Transcranial Doppler to detect high intensity transient signals (HITS) in the middle cerebral arteries (MCAs). HITS identified as embolic signals were prevalent (P < 0.05) in the MCAs on the same side as severe (70-99%) stenosis (22 of 51 = 43.1%) compared to moderate (30-69%) stenosis (5 of 37 = 13.5%). No HITS were observed in the MCA on the same side as normal control carotid arteries (n = 17) [occluded arteries (n = 5) were not considered]. HITS were more prevalent (P < 0.05) in the MCAs on the same side as ulcerated plaques (14 of 23 = 60.9%) compared to non-ulcerated plaques (13 of 65 = 20%), and all moderate stenoses producing HITS presented ulceration of the plaque. Ulcerated plaque groups showed a higher mean number of HITS than non-ulcerated plaque groups and no significant difference was noted between moderate and severe stenosis, between superficial or deep ulcerations and between ulcerations with flap or without flap. Therefore, severe carotid stenosis and moderate stenosis with plaque ulceration result in angiographic findings most frequently associated with HITS. Further studies are necessary to evaluate the clinical significance of this finding.

Aged↗
PubMed1997

Silent cerebral microembolism in asymptomatic and symptomatic carotid artery stenoses of low and high degree.

124 carotid arteries of 62 patients with unilateral or bilateral carotid stenosis proven by selective angiography were investigated by transcranial Doppler to detect high-intensity transient signals (HITS) in the middle cerebral arteries (MCAs). HITS identified as embolic signals were detected in 29 of 124 (23.3%) MCAs and in all cases were asymptomatic. HITS were more common in the MCAs on the same side as high-degree (> 70%) carotid stenoses (24 of 57 = 42.2%) compared with low-degree (< 70%) carotid stenoses (5 of 28 = 17.9%, p < 0.05). No HITS were detected in the MCAs on the same side as normal (24) and occluded (15) carotid arteries. About the clinical features related to the stenoses, HITS were detected with a nonsignificant prevalence in the MCAs on the same side as symptomatic stenoses (16 of 43 = 37.2%) compared with asymptomatic stenoses (13 of 42 = 30.9%) and a relationship between HITS number and time elapsed from symptoms was observed. All symptomatic carotid stenoses > 70% (33) underwent endarterectomy and none of them showed HITS after surgical treatment. These results encourage the feasibility of prognostic studies to evaluate the clinical significance of embolic signals and suggest that silent microembolism could be helpful in selecting a high-risk group of asymptomatic or < 70% carotid stenoses for endarterectomy.

Aged↗
PubMed1997

Radiation-induced cerebral meningiomas. Case reports.

Two cases are presented of meningiomas following external cranial irradiation in which several features clearly indicate a causal relationship between radiotherapy and tumour development. In one patient multiple recurred meningioma was diagnosed 30 years after low-dose X-ray treatment of Tinea capitis; in the other patient the meningioma was diagnosed approximately 18 years after high-dose radiation therapy for astrocytoma. The features distinguishing radiation-induced meningiomas from other meningiomas are reviewed. The use of radiation therapy only in those cases in which there is clear evidence that it will have beneficial effects and that these effects will outweigh the risks is emphasized.

Adult↗
PubMed1996

Resection of single brain metastasis in non-small-cell lung cancer: prognostic factors.

Combined resection of primary non-small-cell lung cancer and single brain metastasis is reportedly superior to other treatments in prolonging survival and disease-free interval. To identify prognostic factors that influenced survival we reviewed clinical records and follow-up data of 52 consecutive patients with non-small-cell lung cancer and single brain metastasis who had been evaluated for combined lung and brain operation: 19 had synchronous and 33 metachronous non-small-cell lung cancer and single brain metastasis. Seven patients were excluded from combined operation because of either early brain relapse after craniotomy or single brain metastasis localization in deep brain structures. Forty-one of the 45 patients who underwent combined operation had complete remission of neurologic symptoms. Actuarial 5-year survival from the second surgical intervention was 16% (median 19 months, range 1 to 104 months). N0 status and lobectomy were the only variables associated with longer survival. Actuarial 5-year survivals in patients with synchronous and metachronous presentation were 6.6% and 19%, respectively. In patients with metachronous presentation the length of survival was significantly associated with N0 status, lobectomy, and interval between lung and brain operation equal to or longer than 14.5 months. The subset of patients with N0 status and interval between operations longer than 14.5 months had a 61% 5-year survival. None of the patients with N1-2 disease and shorter interval between operations was alive at 20 months. These data indicate that prognostic factors may help to identify subsets of patients with markedly different outcomes after combined lung and brain operation.

Adult↗
PubMed1996

Clinical and biochemical screening for Smith-Lemli-Opitz syndrome. Italian SLOS Collaborative Group.

Smith-Lemli-Opitz syndrome (SLOS) is a multiple congenital anomalies/mental retardation disorder possibly due to a defect of delta 7-sterol reductase, leading to low plasma cholesterol levels and to the accumulation of 7-dehydrocholesterol (7-DHC) and other cholesterol precursors. This study aimed to identify clinical features that could potentially be specific indicators for the clinical diagnosis of SLOS, and to test the reliability of ultraviolet spectrophotometry (UVS) as a biochemical screening procedure for the syndrome. Twenty patients with clinical suspicion of SLOS, referred to 11 Italian paediatric and clinical genetic centres, were collected during 1994. In 10 patients the diagnosis was confirmed biochemically by gas chromatography/mass spectrometry (GC/MS) analysis of serum sterols, whereas in the other 10 patients the serum sterol profiles were normal. A comparison between confirmed SLOS patients and biochemically negative subjects did not show clinical signs specific for the syndrome. UVS measurement of 7-DHC correlated well with GC/MS profiles, showing 100% sensitivity and specificity. Four out of five patients had serum bile acid concentrations below the normal range of controls.

Adolescent↗
PubMed1996

Early detection of lung involvement in lysinuric protein intolerance: role of high-resolution computed tomography and radioisotopic methods.

Pulmonary disease of unknown etiology is a potentially fatal complication in patients with lysinuric protein intolerance (LPI), an autosomal recessive disorder caused by the defective transport of cationic amino acids. Lung involvement was investigated in nine Italian LPI patients through pulmonary function tests and lung imaging studies consisting of conventional chest radiography, high-resolution computed tomography (HRCT), and perfusion and ventilation scintigraphy. One 10-yr-old patient died of severe respiratory insufficiency from alveolar proteinosis. All of the remaining patients were asymptomatic at the time of the study, although HRCT scans revealed signs of lung involvement defined by the presence of acinar nodules, inter- and/or intralobular thickening of the interstitial septa, and subpleural cysts in five of the patients. Radioisotope studies showed an uneven distribution of perfusion and ventilation, and confirmed the presence of segmental and/or diffuse pulmonary functional defects. No abnormalities of pulmonary function were evident, and answers to a questionnaire excluded primary coexisting lung disease. In patients with LPI, including those without clinical and functional impairment, HRCT and radioisotopic studies appear to be the most sensitive methods for the early diagnosis of lung disease and correct assessment of its progression.

Adult↗
PubMed1995

Variable penetrance of hypogonadism in a sibship with Kallmann syndrome due to a deletion of the KAL gene.

We report on the clinical and molecular characterization of 3 sibs with X-linked ichthyosis and variable expression of Kallmann syndrome. One of the affected brothers had mild hyposmia and showed normal pubertal progression. However, we demonstrated the same partial deletion of the X-linked Kallmann gene, sparing the first exon in the mildly affected patient as well as in one of his severely affected brothers.

Adolescent↗
PubMed1995

A cluster of sulfatase genes on Xp22.3: mutations in chondrodysplasia punctata (CDPX) and implications for warfarin embryopathy.

X-linked recessive chondrodysplasia punctata (CDPX) is a congenital defect of bone and cartilage development characterized by aberrant bone mineralization, severe underdevelopment of nasal cartilage, and distal phalangeal hypoplasia. A virtually identical phenotype is observed in the warfarin embryopathy, which is due to the teratogenic effects of coumarin derivatives during pregnancy. We have cloned the genomic region within Xp22.3 where the CDPX gene has been assigned and isolated three adjacent genes showing highly significant homology to the sulfatase gene family. Point mutations in one of these genes were identified in five patients with CDPX. Expression of this gene in COS cells resulted in a heat-labile arylsulfatase activity that is inhibited by warfarin. A deficiency of a heat-labile arylsulfatase activity was demonstrated in patients with deletions spanning the CDPX region. These data indicate that CDPX is caused by an inherited deficiency of a novel sulfatase and suggest that warfarin embryopathy might involve drug-induced inhibition of the same enzyme.

Abnormalities, Drug-Induced↗
PubMed1995

Lysinuric protein intolerance characterized by bone marrow abnormalities and severe clinical course.

STUDY OBJECTIVE: To evaluate phenotypic variability of lysinuric protein intolerance in a cohort of nine Italian patients. DESIGN: Retrospective analysis of patient records. SUBJECTS: Nine Italian patients (seven independent families), all originating from southern Italy, observed during the last 14 years. RESULTS: Some of the patients had unique clinical features, including bone marrow abnormalities featuring erythroblastophagocytosis (five patients) and clinical course and the outcome of the disease, have also been observed: respiratory involvement was present in five cases, with a lethal picture of "alveolar proteinosis" in one. Severe kidney involvement, with both glomerular and tubular damage and rapidly progressing to chronic renal failure, has been observed in one case. CONCLUSION: Lysinuric protein intolerance may cause severe multisystem involvement, which requires early and careful monitoring. Some peculiar clinical findings observed in Italian patients point to a genetic heterogeneity of lysinuric protein intolerance.

Adolescent↗
PubMed1995

Anterior fossa dural arteriovenous malformation discovered by means of PW-Doppler examination.

One case of dural arteriovenous malformation in the base of the anterior cranial fossa is reported. It was discovered by means of a PW-Doppler examination of angular branch of the ophthalmic artery in a patient under observation for hypertrophy of a superficial temporal artery. The nidus was located in the region of the cribriform plate and fed by the anterior ethmoidal arteries of both sides, draining into the superior sagittal sinus, via pial enlarged veins. The patient successfully underwent surgical treatment and a post-operative PW-Doppler confirmed normalization of the flow pattern in the angular branches of both ophthalmic arteries.

Cerebral Angiography↗
PubMed1995

Electrophysiological monitoring for selective shunting during carotid endarterectomy.

Selective shunt during carotid endarterectomy is more and more widespread, but it requires a monitoring system able to identify severe brain ischemia correctly. In 255 endarterectomies for severe carotid stenosis, we evaluated cerebral activity by means of sequential use of computerized two-channel electroencephalogram (EEG) and somatosensory evoked potentials (SSEPs). In 1.96% of cases, we observed changes referable to severe cerebral ischemia: in one case, in spite of shunting, EEG asymmetry persisted till the end of the operation, and the patient awoke with irreversible aphasia. In two other cases, a progressive disappearance of the cortical wave (N20) occurred in spite of a normal EEG pattern. None of the unshunted patients had postoperative deficit. Computerized EEG is an easily interpretable method of monitoring and reveals rapidly developing cerebral ischemia, but severe SSEP changes can occur in spite of a normal EEG pattern when cerebral ischemia has a slow onset. Although SSEP monitoring is a slower method of recording, it can give a finer distinction of less severe cerebral ischemia.

Adult↗
PubMed1995

The role of pulse-wave Doppler sonography in quantifying internal carotid stenosis.

To determine the accuracy of pulse-wave Doppler (PWD) sonography in quantifying cervical internal carotid artery (ICA) stenosis, we compared results of PWD with conventional digital subtraction angiography (DSA). A total of 202 carotid arteries were evaluated by means of these two techniques. The patients were divided into four groups according to the percentage of angiographic carotid stenosis as suggested by NASCET. A mathematic model of quadratic relationship between DSA stenosis and blood flow velocity, recorded by PWD, was worked out; peak systolic velocity and mean velocity values, corresponding to 70% DSA stenosis, were employed as key values to check PWD ability to detect high-grade stenosis. Finally, for each case, the correlation between the two techniques was evaluated. PWD well correlates with DSA, making it possible to detect and correctly quantify high-grade ( > 70%) ICA stenosis. In 4 cases with moderate ICA stenoses, blood flow velocity values were over the key values: in cases of moderate angiographic ICA stenosis, PWD identifies those patients in whom the haemodynamic pattern is comparable to the higher group, providing further matter for discussion in order to define surgical selection criteria.

Adult↗
PubMed1995

Immunological disorder and Hirschsprung disease in round femoral inferior epiphysis dysplasia.

We describe a case of semi-lethal chondrodysplasia with skeletal manifestations, detectable at birth, typical of the round femoral inferior epiphysis dysplasia (RFIED) or 'Glasgow' variant. Immunological abnormalities and Hirschsprung disease, so far described only in cartilage hair hypoplasia (CHH), were documented during the first months of life in our patient. These findings confirm the hypothesis that RFIED is a form of CHH with early infantile onset.

Epiphyses↗