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Biomedical subjects

A Ferrari

Publications and source records attributed to A Ferrari.

At least 415 records · Page 23Linked to original sources
PubMedDate not supplied

Identification of [14C]carmoisine metabolites in bacterial suspension of rat faeces.

An in vitro system consisting of a bacterial suspension of human or rat faecal microflora brought about the biological reduction of the red azo dye [14C]carmoisine to 1-naphthyl-amine-4-sulphonic acid (NA) and 2-amino-1-naphthol-4-sulphonic acid (ANA). These metabolites have been unequivocally identified by radio-HPLC, spectroscopic methods, dilution with cold authentic standards and evidence that the specific activity of the diluted compounds remained constant throughout repeated crystallization, acetylation and purification. The results clearly indicated that samples derived from anaerobic incubations have to be processed for analysis in the complete absence of oxygen. In the presence of oxygen, the formation of a complex pattern of compounds in addition to NA was observed as a consequence of the chemical decomposition of ANA.

Adult↗
PubMedDate not supplied

Nasopharyngeal carcinoma in a boy with fragile X syndrome.

The authors report on what they believe to be the first case of nasopharyngeal carcinoma in a patient with fragile X syndrome. In the literature, a few cases of fragile X syndrome associated with malignancies are described. Although this association seems more than coincidental, the molecular correlation between this syndrome and cancer is yet unclear.

Adolescent↗
PubMedDate not supplied

Childhood liposarcoma: a single-institutional twenty-year experience.

A retrospective observational study was performed on a series of 12 consecutive pediatric patients treated over a 20-year period at the Istituto Nazionale Tumori, Milano. Conservative surgery was the treatment of choice in all patients; radical excision was obtained at diagnosis in 9 cases and after primary chemotherapy in 1 case. Five patients were subjected to surgery alone, and one to postoperative radiotherapy. After a median follow-up of 11 years (range 1-20), all the patients were alive without evidence of disease, 11 in first complete remission, and 1 after local relapse. In agreement with other reports, the authors underline the unquestionable pivotal role of radical surgery in the treatment of liposarcoma. The high proportion of resectable tumors accounts for the excellent survival of the patients in this study. The role of both adjuvant chemotherapy and radiotherapy is uncertain and awaits multicentric cooperative prospective studies.

Adolescent↗
PubMedDate not supplied

Evaluation of a slow-release clonidine preparation by direct continuous blood pressure recording in essential hypertensive patients.

The antihypertensive effect of a slow-release (SR) clonidine preparation was evaluated in hypertensive patients not confined to bed using a 24-h intraarterial blood pressure monitoring (Oxford) method. The monitoring was carried out during placebo administration and after 7-10 days of daily administration of SR clonidine in a single oral dose (250 or 500 microgram). An analysis of all the blood pressure values obtained was performed by computer. The results were as follows: (a) SR clonidine significantly reduced the 24-h systolic and diastolic arterial pressure by 16 and 10 mm Hg, respectively (mean +/- SE). (b) The reduction was well evident throughout the 24-h period, the average decrease in mean arterial pressure observed during the first, second, and third 8-h period after the administration of the drug being 11, 14, and 14 mm Hg, respectively. (c) The blood pressure reduction was similar during the daytime and the nighttime, despite the lower base-line value that occurred in the latter condition. (d) There was no consistent change in blood pressure variability, as measured in each patient by the standard deviation of the blood pressure values, with SR clonidine. SR clonidine caused a reduction in heart rate that, as that in blood pressure, was well evident throughout the 24 h. It is concluded that SR clonidine is an effective antihypertensive agent and that a single administration of this drug can produce a clear-cut reduction in the blood pressure values of hypertensive patients for a 24-h period.

Adult↗
PubMedDate not supplied

Disseminated Burkitt's lymphoma after kidney transplantation: a case report in a boy with Drash syndrome.

PURPOSE: We discuss the clinical, laboratory findings and treatment of a boy who developed Burkitt's lymphoma (BL) after renal transplant and some issues about lymphoproliferative disorders after transplantation. METHODS: A 6-year-old boy with Drash syndrome developed disseminated Burkitt's lymphoma 38 months after transplantation for renal failure. Immunosuppressive therapy had consisted of prednisolone and cyclosporine. Polychemotherapy was initiated. RESULTS: Polychemotherapy induced rapid and complete remission of the disease without major side effects despite the renal transplant allograft and prolonged immunosuppression. CONCLUSIONS: A child with posttransplantation B-cell high-grade lymphoma can be successfully treated with the same chemotherapy regimen used for ordinary cases.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Palliative care for intestinal obstruction in recurrent ovarian cancer: a multivariate analysis.

Bowel obstruction is the most common complication in patients with ovarian cancer. Management of this situation is controversial. The aim of our retrospective study was to determine the best approach for managing bowel obstruction in recurrent ovarian cancer. A retrospective analysis of data on 47 patients with intestinal obstruction by ovarian cancer was performed. Twenty-seven patients were submitted to surgery, with 21 intestinal procedures performed, 2 gastrostomy tubes placed, and 4 patients deemed inoperable. Twenty patients were managed medically with Octreotide (mean dosage of 0.48 mg/day), of which 1 patient required a nasogastric tube. Age, performance status, diagnosis of tumor to occlusion time, obstruction site, previous chemotherapy or radiotherapy, presence of ascites, or palpable masses were the variables analyzed. Student's t-test and Pearson chi-square test were used to compare the two different groups of treatment (surgical vs medical therapy). Disease-free-survival curves were plotted according to the Kaplan-Meier method and analyzed by the log-rank test. Cox's proportional hazards model was used for multivariate analysis. Values less than or equal to 0.05 were considered significant. The mean age of the patients was 58.7 years. Perioperative mortality and morbidity were both 22%. All patients died with minimal distress. Performance status results were significantly different between the patients submitted to surgery and patients treated with Octreotide (P= 0.03). No significant differences were found in the other variables analyzed. In multivariate analysis, only type of treatment emerges as a strong predictor of poor outcome (P < 0.001). Both surgery and Octreotide therapy are able to control distressing symptoms in end-stage ovarian cancer. Survival was significantly longer in the surgical group, and surgical palliation should be considered first in patients with good performance status.

Adult↗
PubMedDate not supplied

Clonidine and carotid baroreflex in essential hypertension.

Clonidine is believed to reduce blood pressure by a neural action and animal experiments suggest that this consists in potentiation of baroreflexes. In 16 patients with essential hypertension we studied the effects of alterations in carotid sinus baroreceptor activity (neck chamber technique) on arterial blood pressure (catheter measurements) and heart rate, before and after intravenous administration of 150 microgram and 300 microgram of clonidine. The magnitude of the reflex responses was assessed by the slope of the linear regressions relating applied increase and decrease in tissue pressure at the carotid sinus (and therefore applied decrease and increase in carotid sinus transmural pressure) and resulting changes in mean arterial pressure and R-R interval. Clonidine caused a marked reduction in mean arterial pressure (-26 +/- 3 mm Hg) and a slight but significant reduction in heart rate (-5 +/- 1 b/min). There was no evidence for a potentiation of the baroreceptor influence on blood pressure, although a slight potentiation of the baroreceptor influence on heart rate was observed in few instances. We conclude that in man clonidine can exert a pronounced hypotensive effect without potentiating baroreceptor influence on blood pressure. Therefore this mechanism does not play a prominent role in the clinical antihypertensive action of the drug.

Adult↗
PubMedDate not supplied

Effects of prazosin on autonomic control of circulation in essential hypertension.

Prazosin, an antihypertensive agent that reduces blood pressure (BP) mainly through a blockade of alpha-adrenergic receptors, may, in theory, affect sympathetic control of circulation to an extent that impairs circulatory hemeostasis. This possibility was studied in subjects with essential hypertension by examining the cardiovascular effects of several stimuli that induce a powerful and diversified activation of the sympathetic noradrenergic activity (dynamic and isometric exercise, cold exposure) and of stimuli that exert a powerful inhibitory influence upon the sympathetic nervous system (carotid baroreceptor reflex). Before and after 15 days of continuous administration of prazosin (2-5 mg), 3 times a day, measurements were made of BP (intraarterial catheter), heart rate, cardiac output (thermodilution), and peripheral resistance. Prazosin reduced mean arterial pressure (10%) and peripheral resistance (9%) at rest, and it did not affect heart rate and cardiac output. Neurally mediated changes in arterial pressure, cardiac output, and peripheral resistance during dynamic or isometric exercise and cold exposure were unaffected by the drug; also unaffected were the cardiovascular responses to increase and decrease in carotid baroreceptor activity obtained by varying carotid transmural pressure through a variable neck pressure chamber device. Thus, the hypotensive and vasodilating effect of prazosin in essential hypertension is not accompanied by an impaired response to neural excitation influences upon the cardiovascular system. Also, the inhibitory influences originating from the carotid baroreflex are unchanged. These data indicate that circulatory homeostasis is largely preserved during administration of prazosin at clinically effective doses.

Adult↗
PubMedDate not supplied

Carotid sinus baroreceptor control of arterial pressure in renovascular hypertensive subjects.

We used the neck chamber technique to study carotid baroreceptor control of blood pressure in 18 renovascular hypertensive subjects. Carotid baroreceptors were stimulated or deactivated for 2 minutes by applying graded reductions or increases in the neck tissue pressure (NTP) outside the carotid sinuses. The sensitivity of the baroreflex was separately calculated for these two conditions by the coefficients of the linear regressions relating the changes in NTP to the resulting changes in mean arterial pressure (MAP, catheter measurement). Baroreceptor deactivation increased MAP, and the sensitivity of the baroreflex was 0.12 /+- 0.07 in an early (5 to 1 seconds) and 0.32 /+- 0.05 in a late (90 to 120 seconds) phase of the stimulus application. Baroreceptor stimulation reduced MAP, and the baroreflex sensitivity was in this instance 0.66 /+- 0.08 and 0.05 /+- 0.08 respectively. Both these sensitivities were significantly greater than those obtained for the baroreceptor deactivation. These response entirely reproduced those of essential hypertensive subjects, but differed from those of normotensive subjects in whom baroreflex sensitivity was greater for carotid baroreceptor deactivation than for stimulation. Our findings indicate that carotid baroreceptor control of blood pressure undergoes a marked resetting in renovascular hypertension. The similarity of the baroreflex between renovascular and essential hypertension suggests as secondary origin of the resetting in man.

Adult↗
PubMedDate not supplied

Effects of isometric exercise on the carotid baroreflex in hypertensive subjects.

Previous studies indicate that arterial baroreceptor modulation of heart rate is drastically reduced during static or dynamic exercise. We have investigated whether this reduction also occurs with regard to blood pressure modulation by the baroreflex. The study was performed in 19 subjects with uncomplicated untreated essential hypertension in whom blood pressure was measured intraarterially, and R-R interval was obtained by an electrocardiogram. The carotid baroreceptors were stimulated by neck suction of 30 seconds' duration, and equal stimuli were applied at rest and during hand-grip exercise performed at 40% of the subjects' maximal strength. Baroreceptor stimulation at rest increased R-R interval and reduced blood pressure. During hand-grip, the R-R interval responses to the baroreceptor stimulus were diminished by 61%. In contrast, the blood pressure responses were not significantly altered. Similar results were obtained when two subgroups of subjects with a lesser or greater degree of hypertension were separately considered. Thus, the carotid baroreceptor influence on blood pressure is largely preserved during exercise in contrast to the carotid baroreceptor influence on the sinus node, which is markedly impaired.

Adult↗
PubMedDate not supplied

Twenty-four-hour hemodynamic profile during treatment of essential hypertension by once-a-day nadolol.

The effect of nadolol (N) on 24-hour blood pressure (BP) and heart rate (HR) values and on their variability was examined in ambulant patients with essential hypertension, using the Oxford method to obtain continuous intraarterial recording and a computer to have a beat-to-beat analysis of the data. The recording was carried out without treatment and after 10 days' administration of N once daily by mouth (dose range: 80-320 mg). After N, 24-hour BP and HR were reduced by 17 +/- 3% and 27 +/- 4% respectively as compared to before N, the effect being similar for both systolic and diastolic BP. The hypertension and bradycardia were significantly more marked during the day than during the night, neither showing any attenuation in the hours furthest from the administration of the drug. During N, there was a reduction in the 24-hour variation coefficient for HR but the reduction was limited to the longer term component of this phenomenon, the moment-to-moment variations remaining unaffected. The long- and short-term variation coefficients for BP were not modified under N. These findings suggest that N once a day can reduce BP for 24 hours in ambulant hypertensive patients. The lack of alteration in variability of BP and moment-to-moment HR suggests that the hypotension is achieved without interfering with the mechanisms involved in cardiovascular homeostasis.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Histopathologic interobserver agreement on the diagnosis of melanocytic skin lesions with equivocal dermoscopic features: a pilot study.

AIMS AND BACKGROUND: Dermoscopy (dermatoscopy, skin surface microscopy, epiluminescence microscopy) has been increasingly employed in recent years for the preoperative detection of cutaneous melanoma, and dermatoscopic features of pigmented skin lesions have been previously defined using histopathology (HP) as the "key to the code". The aim of the present study was to evaluate the interobserver agreement on the HP diagnosis in a series of epiluminescence microscopy equivocal melanocytic skin lesions. STUDY DESIGN: Ten melanocytic skin lesions were selected on the basis of diagnostic disagreement of at least 2 out of 9 epiluminescence microscopy observers. The histologic specimens from the 10 lesions were examined by 9 HP observers. The agreement of the HP diagnoses was calculated by means of Fleiss' k statistics. RESULTS: The overall HP agreement was less than excellent (k = 0.5). When considering the prevailing epiluminescence microscopic and HP diagnoses, 2 cases were shown to be epiluminescence microscopy false-negative melanomas. Virtually no agreement was found among epiluminescence microscopy observers in 4 cases (40%) or among HP observers in 3 cases (30%). However, only one pigmented skin lesion remained unclassifiable on epiluminescence microscopy as well as HP. CONCLUSIONS: When at least 2 epiluminescence microscopy experts disagree in the evaluation of a given melanocytic skin lesion, even HP consultations may give equivocal results. The need to establish more reliable epiluminescence microscopic and HP criteria by performing an improved and meticulous clinicopathologic correlation, e.g. by using telecommunication via Internet, is emphasized.

Adult↗
PubMedDate not supplied

Pulmonary asbestosis associated to pleural non-Hodgkin lymphoma.

We describe herein a case report of a patient affected by pulmonary asbestosis who developed a non-Hodgkin lymphoma originating in the pleura. The case is unusual for the uncommon site and because the chronic antigenic stimulation by asbestos bodies may have locally promoted an immunologic derangement.

Aged↗
PubMedDate not supplied

Biomedical applications of cyclotrons and review of commercially available models.

The growing use of cyclotrons in biomedicine, both for clinical and research purposes and in particular for the production of short-lived radionuclides which are extremely useful in nuclear medicine diagnosis, has reached a stage in which commercial companies are able to offer several models with different performances, in order to satisfy the demand of different users. Many of these commercially produced accelerators are installed all over the world and some of them have been operating for several years, demonstrating that this category of machine has reached a high degree of reliability. A brief description of the operating principle of the cyclotron is presented, together with an illustration of its possible applications in the medical field. A list of the models presently available on the market is given and the installation problems and the criteria to be followed in the choice of a model are discussed. Finally, likely future developments in the field are briefly discussed.

Fast Neutrons↗
PubMedDate not supplied

Langerhans cell histiocytosis arising after Hodgkin's disease.

We present the case of a 19-year-old male who suffered from Langerhans cell histiocytosis (LCH) 12 months after having been treated for recurrent Hodgkin's disease (HD). Immunophenotypic characterization and electron microscopic analysis were useful for the exclusion of a bone relapse of Hodgkin's disease or any other differential diagnosis. The association of LCH with HD or other malignancies is rare but more frequent than previously believed. The significance of such an association and the pathophysiology of LCH are still open questions.

Adult↗
PubMedDate not supplied

Malignant peripheral nerve sheath tumors in children: a single-institution twenty-year experience.

A retrospective series of pediatric patients with localized malignant peripheral nerve sheath tumors (MPNST) treated during a 20-year period at one institution is reported. Between 1976 and 1996, 24 consecutive children were treated by a multimodality approach. Conservative surgery was the treatment of choice: primary radical surgery was performed in 10. Postoperative radiotherapy was administered in 12 and adjuvant chemotherapy in 19. Eight patients were alive without evidence of disease, six in first complete remission and two in second complete remission, after a median follow-up of 230 months. The 10-year event-free survival (EFS) and survival were 29% and 41%, respectively. Survival was 80% for the patients who underwent radical surgery, and 14% for the others; 71% for patients with tumors smaller than 5 cm, and 29% for those with tumors 5 cm or larger. Local recurrence was the major cause for treatment failure (13 of 17; 76%); the rate of local relapse was 33% v 75% in patients who either received or did not receive radiotherapy. Complete surgical excision remains the most effective treatment for MPNST and represents the main prognostic factor along with tumor size. Radiotherapy seems to play a role in achieving local control, whereas the role of chemotherapy is uncertain.

Adolescent↗