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L Bordi

Publications and source records attributed to L Bordi.

At least 19 recordsLinked to original sources
PubMed2001

In vivo binding and hierarchy of assembly of the yeast RNA polymerase I transcription factors.

Transcription by RNA polymerase I in Saccharomyces cerevisiae requires a series of transcription factors that have been genetically and biochemically identified. In particular, the core factor (CF) and the upstream activation factor (UAF) have been shown in vitro to bind the core element and the upstream promoter element, respectively. We have analyzed in vivo the DNAse I footprinting of the 35S promoter in wild-type and mutant strains lacking one specific transcription factor at the time. In this way we were able to unambiguously attribute the protections by the CF and the UAF to their respective putative binding sites. In addition, we have found that in vivo a binding hierarchy exists, the UAF being necessary for CF binding. Because the CF footprinting is lost in mutants lacking a functional RNA polymerase I, we also conclude that the final step of preinitiation-complex assembly affects binding of the CF, stabilizing its contact with DNA. Thus, in vivo, the CF is recruited to the core element by the UAF and stabilized on DNA by the presence of a functional RNA polymerase I.

Binding Sites↗
PubMed2000

[The effect of cardiovascular rehabilitation on the variability of the RR cycle after a first uncomplicated acute myocardial infarct].

BACKGROUND: The aim of this study was to verify the changes in the autonomic balance by means of heart rate variability assessment in patients with myocardial infarction referred for cardiac rehabilitation. METHODS: We studied 122 patients (79 males, 43 females, mean age 56 +/- 5 years), with a first uncomplicated myocardial infarction (anterior 48, thrombolysis 72), Killip class 1, preserved left ventricular function (ejection fraction 49 +/- 6%). All patients were free of inducible residual ischemia. Four weeks after myocardial infarction, patients were randomized into two groups; Group 1 (n = 58) referred for an 8 week cardiac rehabilitation program (scheduled: 24 sessions); Group 2 (n = 64): normal daily physical activity. During a 24-hour Holter ECG monitoring the following parameters were calculated in pharmacological wash-out at randomization (T0) and at the end of cardiac rehabilitation/control period (T1): mean value of RR intervals (RR), its standard deviation (SDNN), pNN50, rMSSD in the time domain; low frequency (LF) and high frequency (HF) value and the LF/HF ratio in the frequency domain. T1-T0 changes in percent values (delta %) were considered and compared between the two groups. RESULTS: Thirty-one patients were excluded from the study either for insufficient adhesion to the cardiac rehabilitation program (< 13 sessions, 22 patients) or recurrent ischemia (3 Group 1 patients and 3 Group 2 patients) and non-assessable 24-hour Holter ECG monitoring (3 patients). Thirty-one Group 1 patients and 60 Group 2 patients completed the study with a first and a second 24-hour Holter ECG monitoring performed at 30 +/- 3 days and 60 +/- 4 days respectively. At the same time an ergospirometric test was performed to evaluate cardiopulmonary function by means of exercise time, maximum oxygen consumption, anaerobic threshold, exercise time at the anaerobic threshold, and maximum oxygen consumption at the anaerobic threshold. Twenty-eight Group 1 patients and 44 Group 2 patients completed the study with a first and a second ergospirometric test. Baseline heart rate variability parameters were comparable in the two groups. During the observation period only in Group 1 patients heart rate variability parameters changed significantly: RR (Group 1 = +18.3 +/- 21.3; Group 2 = +4.2 +/- 5.2, p = 0.000), pNN50 (Group 1 = 45.0 +/- 38.9; Group 2 = +24.2 +/- 34.7, p = 0.011), HF (Group 1 = +81.6 +/- 124; Group 2 = -28.7 +/- 75.4, p = 0.014) and LF/HF ratio (Group 1 = -26.0 +/- 16.1; Group 2 = -4.9 +/- 6.1, p = 0.062). There were no significant differences in SDNN, rMSSD and LF. A linear correlation between delta LF/HF ratio and baseline LF/HF ratio values was found in Group 1 (r = 0.489, p = 0.006), whereas no correlation was found between this parameter and age, ejection fraction, creatine phosphokinase, and infarct localization. Group 1 patients had a significant improvement in exercise tolerance compared to Group 2 patients. CONCLUSIONS: A cardiac rehabilitation program positively modifies the sympatho-vagal balance in patients with uncomplicated myocardial infarction, increasing the parasympathetic tone and exercise tolerance.

Aged↗
PubMed1998

Surgical treatment of intracranial aneurysms in patients aged over 70: 25 years of experience.

Many references and communications regarding neurosurgical topics in elderly patients underline the interest of our Unit for this subject. We already presented in 1978 a series of 75 patients over 60 years of age operated on for intracranial aneurysms; we reported a 90% of success in all the cases operated with clinical grade 1 or 2 according to Botterel grading system on admission. In 1986, during the XXXV Congress of the Italian Neurosurgical Society, we presented other 15 cases operated for intracranial aneurysm over 70 years of age. We present an upgrading of our casistic.

Aged↗
PubMed1997

Two-step development of a pituitary adenoma: from hyperprolactinemic syndrome to Cushing's disease.

In this report we describe the case of a young female patient with amenorrhea-galactorrhea syndrome apparently due to pituitary PRL-secreting adenoma who, after three years of dopaminergic therapy without any shrinkage of the tumor, developed true Cushing's disease. Progression from hyperprolactinemia to hypersecretion of ACTH has been rarely described and it may be due to different possibilities. However, histopathological and immunohistochemical studies of the adenoma showed a pattern of PRL negative and ACTH positive cells, excluding mixed pituitary tumor. In order to explain the progression from hyperprolactinemia with amenorrhea-galactorrhea to an ACTH hypersecretion syndrome, it must be hypothesized either pituitary stalk compression or the influence of paracrine regulation factor(s) (such as Galanine) due to an "initially silent" corticotropinoma. This case confirms that the presence of hyperprolactinemia in a patient with pituitary tumor and amenorrhea-galactorrhea syndrome is insufficient to confidently conclude for prolactinoma. Furthermore, it underlines the importance both of clinically monitoring the patient with prolactin pituitary adenoma if dopaminergic therapy does not reduce tumor volume, and of accurately and repeatedly measuring the other pituitary hormonal secretions.

Adult↗
PubMed1997

Prognostic value of residual ischaemia assessed by exercise electrocardiography and dobutamine stress echocardiography in low-risk patients following acute myocardial infarction.

BACKGROUND: Risk stratification after uncomplicated myocardial infarction is major clinical problem. In particular, the prognostic value of residual inducible ischaemia is still controversial. We compared the relative prognostic value of exercise ECG and dobutamine stress echocardiography performed in the early post-infarction period. METHODS: Four hundred and six patients (53 female) aged 57 +/- 9 years, undergoing maximal exercise ECG and dobutamine stress echocardiography within 10 days of an uncomplicated myocardial infarction off therapy, were prospectively followed-up for 8.8 months. Age, sex, diabetes, smoking habit, hypertension, dyslipidaemia, infarct location, thrombolysis and resting wall motion score index were taken into account among clinical variables. Prognostic correlations were made vs spontaneous events (cardiac death, non-fatal reinfarction and unstable angina requiring hospitalization) whilst patients undergoing revascularization (by means of percutaneous transluminal coronary angioplasty or coronary artery bypass surgery) at the time of the procedure were censored. RESULTS: One hundred and twenty-seven events occurred during the follow-up: 41 (10%) were spontaneous (five deaths, 12 reinfarctions and 24 unstable angina) and 86 procedural (27 angioplasty and 59 bypass surgery). Spontaneous events were not predicted by any clinical, exercise ECG or dobutamine stress echocardiography variable, but the negative predictive value of both tests was excellent (91% and 90% respectively). With a multivariate Cox analysis, male gender, positive low-workload (< 100 W) exercise ECG (P < 0.0001), positive low-dose dobutamine stress echocardiography (P < 0.0001) and rest-stress wall motion score index variation (P < 0.001) were found to predict cumulative cardiac events with an independent and additive value. Dobutamine stress echocardiography was significantly more sensitive (P < 0.05) and less specific (P < 0.01) in predicting the outcome of patients with anterior infarction, whilst exercise ECG was significantly more sensitive (P < 0.05) in patients with non-Q wave infarction. CONCLUSIONS: (1) Spontaneous events are poorly predicted by provocative tests in low-risk patients after uncomplicated myocardial infarction. (2) However, both exercise ECG and dobutamine stress echocardiography can predict a favourable outcome with a very high negative predictive value. (3) Dobutamine stress echocardiography should be considered a secondary option in cases where the exercise ECG is equivocal or when the location of ischaemia is a relevant issue. (4) The possibility that the two tests have a differential utility depending on the infarct location and type (Q wave vs non-Q wave) may be clinically relevant and deserves further evaluation.

Aged↗
PubMed1996

[Prognostic value of echo-dobutamine test in patients with ischemic heart disease: comparison with exercise test].

BACKGROUNDS: The aim of the study was to assess the relative prognostic accuracy of dobutamine echocardiography (TED) vs maximal bicycle exercise electrocardiography (TE) in patients with proven coronary artery disease. METHODS: One hundred and thirty consecutive patients (70 patients with uncomplicated recent myocardial infarction, 19 asymptomatic patients with previous myocardial infarction and 41 patients with stable angina pectoris and previous myocardial infarction or previous myocardial revascularization procedure) underwent TED (incremental dobutamine infusion: 5 to 40 ncg/kg/min, continued with atropine 0.25 to 1 mg iv if necessary) and TE on different days and in random order. Criteria for positivity were: new or worsening regional dyssynergy for TED; ST segment shift > or = 1 mm from baseline for TE. End points were defined as spontaneous events (cardiac death, myocardial infarction and unstable angina) and total events (spontaneous events plus myocardial revascularization procedures). RESULTS: During 15.4 +/- 7.9 (range 1-33) months of follow-up, 33 events occurred: cardiac death (1), myocardial infarction (4) unstable angina (21) myocardial revascularization (7). Sensitivity, specificity, positive and negative predictive value, prognostic accuracy were similar for TED and TE (P = NS). Cumulative event-free survival curves as a function of TED and TE results were both statistically significant. A Cox stepwise regression analysis identified TED positivity obtained without atropine administration as the best predictor of spontaneous and total events (Odds ratio 5.33 and 4.38, respectively). Cumulative survival curves obtained by the combination of TED and TE results were statistically different (P < 0.05 and P < 0.001 for spontaneous and total events, respectively) and showed a poor clinical outcome in patients with both tests or only TED positive. TED correctly predicted clinical outcome in 24/39 patients in whom there was disagreement between the two tests. CONCLUSIONS: In patients with proven coronary artery disease, TED and TE have a similar accuracy for predicting clinical outcome. Where a discrepancy is seen between the two tests, TED appears to have a slightly higher prognostic value.

Aged↗
PubMed1995

Prognostic value of high dose dipyridamole echocardiography in patients with chronic coronary artery disease and preserved left ventricular function.

OBJECTIVES: The prognostic value of dipyridamole echocardiography was assessed in patients with chronic coronary artery disease and preserved left ventricular function. BACKGROUND: Few data are available on the prognostic value of dipyridamole echocardiography in patients with a low risk of cardiac events. METHODS: Two hundred sixty-eight consecutive patients with stable, proven or suspected coronary artery disease and ejection fraction > or = 0.40 underwent high dose (up to 0.84 mg/kg body weight) dipyridamole echocardiography. In 204 patients definite exercise electrocardiographic (ECG) results were also available. RESULTS: During a mean (+/- SD) follow-up period of 16 +/- 8 months (range 6 to 36), 33 spontaneous events occurred: 15 "hard" events (cardiac death [n = 6], myocardial infarction [n = 9]) and 18 "soft" events (unstable angina). Events occurred more frequently in patients with positive findings on dipyridamole echocardiography (59% vs. 3%, p < 0.001; hard events 24% vs. 2%, p < 0.01). A positive response at the low dose (up to 0.56 mg/kg) identified patients with a high incidence of hard events (7 of 16 patients, sensitivity 50%, specificity 96%). In patients with an exercise ECG, a comparable sensitivity for cardiac events was found (89% vs. 93%, p = NS), but dipyridamole echocardiography was more specific (91% vs. 61%, p < 0.01). A positive response on the low work load exercise ECG (< 8 min) and a positive response to low dose dipyridamole echocardiography had similar accuracy (82% vs. 90%, p = NS). Cox analysis identified dipyridamole echocardiography as the best predictor of cardiac events (odds ratio [OR] 20.9, 95% confidence interval [CI] 10.8 to 37.9); the highest risk of hard events was found in patients with a positive response to low dose dipyridamole echocardiography (OR 25.4, 95% CI 12.2 to 54.1). CONCLUSIONS: In patients with chronic coronary artery disease and a low incidence of cardiac events, dipyridamole echocardiography was effective in prognostic stratification, and positive low work load exercise ECG results were a reliable predictor of subsequent events. Consequently, dipyridamole echocardiography should be considered a complementary tool in the presence of high work load positivity or ambiguous exercise ECG results.

Coronary Disease↗
PubMed1993

Surgical management of haemangioblastoma of the posterior fossa.

Fifty-one cases of posterior fossa haemangioblastoma have been seen in our department over a period of 23 years. Seven cases were associated with spinal cord lesions and one with a supratentorial lesion. There were 22 cases of Lindau's disease (43%). The onset was earlier and recurrences commoner than in isolated cases. In 10 cases the development of new tumours in different parts of the central nervous system (CNS) required re-operation, demonstrating the multicentric nature of this disease. The majority of the tumours occupying the fourth ventricle or medulla oblongata (8 cases) were macroscopically solid and had higher post-operative morbidity than the cystic tumours in the cerebellum. The recent development of magnetic resonance imaging (MRI) provides accurate anatomical information of the lesions (especially those of the brain stem and spinal cord) even while asymptomatic. The brilliant enhancement of these tumours on MRI with Gadolinium-diethyline-triamine-pentaacetic acid (Gd-DTPA) has proved to be particularly useful.

Adolescent↗
PubMed1993

Neuromas of the facial nerve: a report of 12 cases.

Twelve patients with facial nerve neurinoma have been treated at The National Hospital, Queen Square, London, during the last 20 years. Nine tumours lay in the middle fossa arising from the area of the geniculate ganglion, two lay in the posterior fossa arising from the segment of the facial nerve in the internal auditory canal, and one tumour arose from the vertical segment of the facial nerve with extracranial extension through the stylomastoid foramen. Two patients had neurofibromatosis. The clinical and radiographic features of those tumours, the operative approaches employed, and the postoperative outcome are described. Complete tumour excision was achieved in all patients; all 12 remain free of recurrence 3-80 months after surgery. Facial nerve function was restored at least in part in all cases by transposition with end-to-end anastomosis, placement of a cable graft from the sural nerve or hypoglosso-facial anastomosis. The major determinant of the outcome of facial nerve function was the duration of preoperative facial paralysis, the results being invariably poor when this was of long duration.

Adolescent↗
PubMed1991

Classification of supratentorial arteriovenous malformations. A score system for evaluation of operability and surgical strategy based on an analysis of 66 cases.

A classification of arteriovenous malformations (AVM) is proposed, which is based on a retrospective analysis of the records and results of radical operation in 57 patients between 1983 and 1990. It represents the new developments and more recent technical facilities which influence operability of supratentorial AVMs. Predictability of outcome has been settled upon three groups of factors: anatomical, haemodynamical, and clinical. Anatomical factors are localisation and sectorisation of AVM, determination, caliber and straightening of feeding arteries. Haemodynamical factors are volume of AVM and vascular autoregulation, circulatory velocity of red blood cells in the main arteries of the neck and brain tissue cellular steal. Clinical factors are age, previous rupture of AVM, associated diseases and malformations of vital organs. Each of these factor groups has been divided into parameters to which a code number from 0 to 5 according to the severity of the considered parameter has been attributed. When a contraindication for radical surgery was clearly obvious, as, for example, an AVM with extension to the upper brain stem, number 10 was given. This grading has been done by a team of four persons (3 neurosurgeons including the senior author, and one biophysicist). By adding up all code numbers an Operability Score for a given patient is defined by the number of points, with a minimum of 3 and a maximum of 69. In cases with a score higher than 30 surgery is not advisable. A score between 21 and 30 indicates that always several staged operations are required, whilst only some of the patients with a score between 11 and 20 may require two stage operative treatment. The AVM in patients with a score under 10 can always be radically excised in a single stage operation. We have been able to demonstrate that the Operability Score allows a reliable prediction of outcome, thus giving indications and contraindications for surgery, and also for the surgical strategy. Moreover, we have explained why surgery had been refused in 9 additional cases during the same period. The causes of 8 fatalities out of 57 surgical cases are analyzed. These 57 cases represent a systematically explored series of the senior author; his experience is based upon 295 personal AVM cases (1958-1990).

Adult↗
PubMed1991

Cavernous angioma of the cerebello-pontine angle: a case report.

A case of cavernous angioma involving the facial nerve is described. The patient presented with decreased hearing on one side and after investigation a small mass was discovered enlarging the internal auditory meatus. The final diagnosis was made at operation. The pathology of this type of malformation is discussed.

Adult↗
PubMed1991

[Unruptured intracranial saccular aneurysms less than 20 mm in diameter in adults. Radical surgery in 89 cases].

Between 1972 and 1989, 131 unruptured intracranial saccular aneurysms were clipped in the Neurosurgical Department of La Pitié Hospital, Paris. Only 89 of these are considered here, the remaining 42 aneurysms having been discovered and clipped during surgery for a ruptured aneurysm. All isolated unruptured aneurysms were detected by angiography, computerized tomography or magnetic resonance imaging. Twenty out of the 89 aneurysms were asymptomatic ("incidental") while 69 were accompanied by clinical symptoms indicating radiological examination. It is generally accepted that in ruptured aneurysms the mortality rate during 3 days following the rupture is about 50 percent, and for this reason many neurosurgeons are in favour of unruptured aneurysms being treated either by open surgery with clipping of the aneurysmal neck or by inserting a balloon into the aneurysmal sac. The results obtained in 377 published cases, including ours, justify this approach: no recurrent bleeding was observed after open surgery and the mortality rate was nil when the contra-indications of surgery were respected. There was a permanent morbidity of less than 2 per cent directly related to the surgeon's experience.

Adult↗
PubMed1990

Haemostatic clips and clamps used in surgical neurology with special reference to non ferro magnetic Phynox spring clips by Aesculap.

This paper concerns the historical developments and technical properties of haemostatic devices used in neurosurgery with the exception of coagulation. Therefore there are described haemostatic clips designed for the scalp, clips used on arteries and veins, a clamp for the reduction of the carotid diameter in the neck, and a clamp for closing the venous dural sinuses. Special reference will be made regarding non ferro magnetic Phynox clips by Aesculap.

Hemostasis, Surgical↗
PubMed1990

Hypoglossal neuroma following excision of a huge recurrent acoustic neuroma and facio-hypoglossal anastomosis. A complex management problem.

A case of neuroma of the intracranial part of the hypoglossal nerve, not associated with neurofibromatosis, is presented. The patient had previously undergone surgery for the removal of a contralateral acoustic neuroma, and subsequent facio-hypoglossal anastomosis. The importance of early diagnosis, pre-operative clinical assessment and post-operative care is stressed.

Adult↗
PubMed1990

Jugular foramen neuromas: a review of 14 cases.

We present 14 patients with jugular foramen neuromas treated in the professorial unit at the National Hospital, Queen Square, in the 20-year period from 1969 to 1989. The growth characteristics and associated symptomatology of these tumors are variable, and often they do not give rise to a typical jugular foramen syndrome, making differentiation from other low cerebellopontine angle tumors difficult and occasionally impossible. One tumor presented mainly in the neck, but the remaining 13 were predominantly intracranial and their anatomical relationships as defined radiologically determined the surgical approach used. Nine tumors were resected using a posterior fossa approach, three required a combined posterior fossa and neck dissection, and one a combined supratentorial and infratentorial craniotomy. The aim of operation was total excision of the tumor, which was achieved in 10 patients; the remaining three all suffered recurrence. There was no operative mortality and little long-term disability.

Adolescent↗