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Biomedical subjects

R Riccardi

Publications and source records attributed to R Riccardi.

At least 91 records · Page 5Linked to original sources
PubMed1991

Recurrent oral condylomata acuminata and hairy leukoplakia: an early sign of myelodysplastic syndrome in an HIV-seronegative patient.

Oral hairy leukoplakia (OHL) has been observed in all risk groups seropositive for HIV infection. Recently, this lesion has also been described in HIV-seronegative patients with immunosuppression of iatrogenic origin. We report on a HIV-1 and HIV-2 seronegative, heterosexual man affected by refractory anemia with ringed sideroblasts (myelodysplastic syndrome), who developed recurrent oral condylomata acuminata and OHL as an early clinical manifestation. The diagnosis of OHL was confirmed by identifying Epstein-Barr viral particles by electron microscopy and by in situ DNA hybridization. HIV infection was ruled out using polymerase chain reaction and testing for HIV-1 and HIV-2 antibodies.

Anemia, Refractory↗
PubMed1991

Anthracycline cardiotoxicity: in vivo and in vitro effects on biochemical parameters and heart ultrastructure of the rat.

The premise of this study is that mitochondrial lesions caused by anthracyclines lead directly to cardiotoxicity. We compared several biochemical parameters, including endogenous cellular respiration, adenosine and guanosine triphosphate levels, and 14C-amino acid incorporation, of rat hearts treated with doxorubicin and some of its derivatives, recent products of pharmacological research aimed at selecting less toxic antiblastic agents. In rats treated in vivo, we further examined the ultrastructural changes induced by anthracycline antibiotics in order to elucidate which biochemical parameters were consistent with the morphological lesions. Our data indicate that mitochondria are the target of the anthracycline effects and that oxygen uptake and nucleotide levels may be regarded as markers of the toxicity when evaluating new drugs before their clinical use. The lack of cytoplasmatic or endoplasmatic reticulum alterations may account for the failure of anthracyclines to affect amino acid incorporation. In any event, the rate of protein synthesis cannot serve as a marker of cardiac toxicity. In this context, epidoxorubicin and iododoxorubicin are two derivatives characterized by less cardiotoxic potential than doxorubicin and thus appear to be promising antiblastic agents.

Adenosine Diphosphate↗
PubMed1990

Oral melanotic macules in patients infected with human immunodeficiency virus.

A group of 217 patients seropositive for human immunodeficiency virus (HIV) were studied for 2 years, during which time pigmented lesions of the oral mucosa developed in 14 (6.4%) of them. The lesions were well circumscribed in some cases and diffuse in others. In some patients the macules enlarged or recurred after surgical excision. In two patients the macules appeared during the administration of zidovudine. Clinical and laboratory evidence of adrenal insufficiency was not detected in any of the patients examined. The histologic appearances were those of melanotic macules. No ultrastructural alterations of the melanocytes were observed. Two of these macules also contained Epstein-Barr virus, and in one case normal oral mucosa was examined and also contained Epstein-Barr virus in the epithelial cells. As a control group we examined 180 health care workers who did not belong to any risk category, and 30 intravenous drug abusers who tested seronegative to HIV. Oral melanotic pigmentation was found in eight of the control subjects (3.6%). The difference was not statistically significant (p = 0.3097). Our study shows that oral macules do not occur more frequently in HIV-infected patients. However, the clinical behavior of these lesions appears to be different during the course of HIV infection. In some HIV-infected patients the cause of the macules might relate to the administration of zidovudine and antifungal or antibacterial drugs. In others the cause remains unknown and could be due to multiple factors.

Adult↗
PubMed1990

Morphology and membrane antigens of nonlymphoid accessory cells in oral hairy leukoplakia.

We have investigated the features and distribution of accessory cells (ACs) and the relationship of these cells to each other and to lymphocytes in the epithelium and lamina propria of oral hairy leukoplakia (HL), with the objective of better defining the differentiation and mutual interactions of immune-response cells within HL as a preliminary step to understanding the onset and significance of this lesion during human immunodeficiency virus (HIV) infection. Twenty-four HIV-infected patients with HL, two asymptomatic HIV-positive subjects, and three HIV-negative subjects were studied by immunohistochemistry; five HIV-positive patients with HL and three asymptomatic HIV-positive subjects were studied by electron microscopy. In both the epithelium and the lamina propria of HL, we found cells with the immunohistochemical and ultrastructural features of variably differentiated ACs; differences were found between the epithelium and lamina propria. In the lamina propria, ACs were characterized by dendritic shape, multiple contacts with lymphocytes, expression of CD1a antigen, and ultrastructural features of fully differentiated ACs. Conversely, in the epithelium ACs showed bluntly dendritic shape, low expression of CD1a, absent expression of HLA-DR, constant expression of CD11c and CD14 antigens, only occasional contacts with lymphocytes, and ultrastructural features of variably, but always incompletely, differentiated cells of monocyte-dendritic lineage. Seventy-nanometer wide intracisternal particles, closely resembling A particles described in retroviral infections, were found in the intraepithelial ACs in two patients with HL. The defective differentiation of ACs in the epithelium of HL--possibly influenced by the perturbation of the epithelial microenvironment induced by Epstein-Barr virus, and following the direct HIV infection of these cells--and the exceptional finding of close contacts with lymphocytes suggest that the lesional epithelium of HL may constitute a pathway for the entry of foreign antigens which circumvent monitoring by ACs and can induce immune tolerance. The impairment of the local immune response in HL may contribute to the development of full blown, systemic immunodeficiency.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Relation between spontaneous atrial fibrillation and atrial vulnerability in patients with Wolff-Parkinson-White pattern.

An intracavitary electrophysiological study was carried out on 103 patients with Wolff-Parkinson-White (WPW), 23 symptomatic patients had documented episodes of atrial fibrillation, 54 symptomatic patients had atrioventricular reentrant tachycardias, and 26 asymptomatic. Patients were examined for the relation between spontaneous atrial fibrillation and atrial vulnerability, defined as the possibility to induce sustained (greater than 1 minute) episodes of atrial fibrillation with a stimulation protocol excluding atrial bursts. Atrail fibrillation induction was attempted by single and double atrial extrastimuli during pacing at two different cycle lengths and incremental atrial pacing. Sustained atrail fibrillation was induced in 65% of the patients with spontaneous atrial fibrillation, and in 13% of the symptomatic patients with documented episodes of atrioventricular reentrant tachycardias and in 15% of the asymptomatic patients (P less than 0.0005). Atrial vulnerability was higher in patients with spontaneous atrial fibrillation than in patients without this arrhythmia. No significant difference was observed between symptomatic without atrial fibrillation and asymptomatic patients.

Adult↗
PubMed1990

[Oral hairy leukoplakia in patients with HIV infection].

Oral hairy leukoplakia is a new clinicopathological entity. Little is known about its etiology, pathogenesis and natural history. It is considered a specific marker of HIV infection, although it has been also reported in HIV-negative patients. The etiology appears related to Epstein-Barr virus. Hairy leukoplakia has a characteristic clinical and histopathological aspect, but it is not specific. Because hairy leukoplakia may be easily confused with other lesions of the tongue, the dentist should be very careful in making the final diagnosis. Hairy leukoplakia is usually asymptomatic and treatment is not necessary. In cases of extensive lesions or psychological intolerance of the patient, useful drugs are acyclovir and vitamin A derivatives.

Diagnosis, Differential↗
PubMed1990

[Induction of atrial tachyarrhythmia in patients with Wolff-Parkinson-White syndrome with and without spontaneous atrial fibrillation].

The purpose of this study was to examine the relation between spontaneous atrial fibrillation and the induction of atrial tachyarrhythmias during electrophysiologic study in patients with Wolff-Parkinson-White, with and without atrial fibrillation. Intracavitary electrophysiologic study was performed on 115 patients, 27 with spontaneous atrial fibrillation (group 1), 57 symptomatic due to AV re-entrant tachycardias, without spontaneous atrial fibrillation (group 2) and 31 asymptomatic (group 3). Induction of atrial fibrillation was attempted by using single and double atrial extrastimuli during atrial pacing at 2 different cycle lengths and by incremental atrial pacing (protocol A). When atrial fibrillation was not obtained, atrial bursts were added (protocol B). Atrial fibrillation or flutter were induced in 81% of group 1.54% of group 2 and 55% of group 3 patients (p less than 0.05), using protocol A. They were induced in 100, 75 and 71%, respectively (p = 0.01), with protocol B. Considering only sustained (greater than 1 minute) episodes, atrial fibrillation or flutter were induced in the three groups with protocol A in 74, 33 and 32% of the patients, respectively (p less than 0.001). The difference in the three groups was even greater when atrial fibrillation was considered separately from atrial flutter. The reason for this was that atrial fibrillation was induced in two thirds of group 1 patients, while only about 15% of patients without spontaneous atrial fibrillation had this arrhythmia induced. Our results suggest that the induction of sustained atrial fibrillation is a useful parameter to separate Wolff-Parkinson-White patients with from those without spontaneous atrial fibrillation. Due to the low specificity of the analysis of the shortest R-R interval during induced atrial fibrillation for the identification of the patients at risk of sudden death, the induction of sustained atrial fibrillation could be proposed as an additional parameter. This would improve the specificity of electrophysiologic study.

Adult↗
PubMed1989

Stress and pharmacologic tests as methods to identify patients with Wolff-Parkinson-White syndrome at risk of sudden death.

Noninvasive stress and pharmacologic tests with procainamide and propafenone were studied as methods to identify patients with Wolff-Parkinson-White syndrome (WPW) who would otherwise be judged at risk of sudden death on the basis of electrophysiologic criteria: the shortest RR interval during induced atrial fibrillation less than or equal to 250 ms or accessory pathway anterograde effective refractory period less than or equal to 250 ms. Sixty-five patients were studied. Twenty-four patients fulfilled the electrophysiologic risk criteria (group A) and 41 patients fulfilled none of these criteria (group B). Persistence of preexcitation during stress test showed a sensitivity of 96% and a specificity of 17% to identify group A patients; its positive predictive value was 40% and negative predictive value 88%. With both procainamide and propafenone tests persistence of preexcitation identified group A patients with a sensitivity of 96% and a specificity of 51%; their positive and negative predictive value were, respectively, 53 and 95%. Stress and pharmacologic tests have good sensitivity and negative predictive value, but low specificity and positive predictive value.

Adolescent↗
PubMed1989

131I-metaiodobenzylguanidine in the treatment of neuroblastoma at diagnosis.

Radioactive metaiodobenzylguanidine (131I-MIBG) is taken up specifically by neuroblastoma cells and appears to represent a new treatment modality in patients with advanced neuroblastoma. Taking into account the fact that all patients so far treated were heavily pretreated and resistant to chemotherapy, the results obtained appear encouraging. In order to explore further the potential role of this new drug in untreated patients, we treated with 131I-MIBG a child with stage III neuroblastoma at diagnosis. We observed the complete disappearance of a large abdominal tumor mass after a relatively low dosage of 131I-MIBG, with minimal hematologic toxicity. No further treatment was given and, at present, the patient is alive with no evidence of disease 18 months from diagnosis. This child represents, to our knowledge, the only case of neuroblastoma thus far treated at diagnosis and the excellent response obtained suggests the need for further investigations of this therapy in untreated patients.

3-Iodobenzylguanidine↗
PubMed1988

Correlation between cranial computed tomographic scans at diagnosis in children with acute lymphoblastic leukaemia and central nervous system relapse.

145 children with acute lymphoblastic leukaemia (ALL) were evaluated over a period of 3 years in a multicentre study in which serial cranial computed tomographic (CT) scans of the brain were done. All patients were symptom-free. CT scans were graded as normal, borderline (slight or moderate cerebral atrophy), or pathological (severe cerebral atrophy). 62% (90/145) of children had CT scan abnormalities at diagnosis. After a median follow-up of 24 months (range 6-36) 12 of 108 evaluable patients had central nervous system (CNS) relapses (6 isolated relapses and 6 combined with relapse at another site). All patients with CNS relapse had an abnormal CT scan at diagnosis (8 pathological and 4 borderline). No relapses were observed among the 42 patients with a normal cranial CT scan at diagnosis. A significantly higher proportion of severe cerebral atrophy, both following CNS prophylaxis and after the discontinuation of treatment, was found among patients with a borderline CT scan at diagnosis than among patients with a normal CT scan at diagnosis. Thus an abnormal cranial CT scan at diagnosis in children with ALL seems to have prognostic significance.

Adolescent↗
PubMed1988

Oral hairy leukoplakia among HIV-positive intravenous drug abusers: a clinicopathologic and ultrastructural study.

During a prospective investigation of oral lesions of 120 consecutive patients positive for human immunodeficiency virus, belonging to the intravenous drug abuser risk group and other risk categories, we observed hairy leukoplakia (HL) in 23 cases (19%). The median age of the patients was 27 years (range, 20 to 50 years). Twenty patients were men and three were women. All but two of the twenty three patients used intravenous drugs for a median period of 6 years (range, 5 to 18 years) and were involved in several episodes of needle sharing. Eight men were also bisexual, one man was homosexual, and one man was hemophiliac and bisexual. Eleven patients had asymptomatic infection, five had lymphadenopathy syndrome, six had AIDS-related complex, and one had acquired immunodeficiency syndrome. In all patients, HL lesions were localized on the lateral borders of the tongue. In twelve patients, the lesion was unilateral, and in eleven patients, it was bilateral. Microscopically, hyperparakeratosis and the presence of koilocytes were observed in all cases. Surface candidiasis could be detected with staining with periodic acid-Schiff in two thirds of the cases. In four cases, electron microscopy showed the presence of intracellular and extracellular hyphae of Candida albicans in the parakeratin layer associated with coccobacilli in the spaces between surface epithelial cells. The spinous layer included koilocytes, which had a clear cytoplasmic matrix, sparse organelles and tonofilaments, and dispersed chromatin. These cells were found to be infected by a herpes-type virus in all cases examined. There was no ultrastructural evidence of human papillomavirus in the nuclei of the epithelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗
PubMed1987

Treatment of neuroblastoma with 131I-metaiodobenzylguanidine.

Seven patients with neuroblastoma (six children and one adult) were treated with therapeutic doses of high specific activity 131I-metaiodobenzylguanidine (131I-MIBG). Six patients were in stage IV and unresponsive to conventional treatment. One patient, in stage III, was treated at diagnosis, an approach never previously reported. Single doses of 131I-MIBG varying from 70 to 184 mCi split into two parts were administered by slow i.v. infusion (4 to 8 hours) at 2- to 4-day intervals. The following results were obtained in the six evaluable patients: two patients showed transient stabilization of the disease; three had an objective response, with shrinking of the primary tumor and/or regression of the metastatic lesions. Of these three patients, two suffered relapses at 2 and 7 months, respectively, from the first course of MIBG. The third patient, in whom the residual disease almost completely disappeared following MIBG therapy, is still alive in complete remission after autologous bone marrow transplantation with a follow-up of 14 months. The single patient treated at diagnosis showed a dramatic response to a relatively low dosage of MIBG, with histologically proved disappearance of the tumor mass. Our data indicate that MIBG may be useful in the treatment of neuroblastoma unresponsive to conventional chemotherapy. The complete response observed in the patient treated at diagnosis suggests that the full potentiality of MIBG therapy should be explored in untreated patients.

3-Iodobenzylguanidine↗
PubMed1987

[Electrophysiologic study in supine and upright positions in patients with Wolff-Parkinson-White syndrome].

It is well known that in patients with Wolff-Parkinson-White (W.P.W.) adrenergic activity stimulation induced by exercise or isoproterenol I.V. infusion shortens the anterograde effective refractory period (E.R.P.) of the accessory pathway. Our purpose was to evaluate whether the upright position produces similar changes on the electrophysiologic properties of the accessory pathway and influences reciprocating tachycardias induction. In 18 patients, with W.P.W. syndrome, who underwent electrophysiologic study, we determined the anterograde E.R.P. of the accessory pathway and attempted to induce a reciprocating tachycardia in the supine and in the upright position. In 13 patients (72%) the anterograde E.R.P. of the accessory pathway shortened in the upright position (303 +/- 104 msec vs 331 +/- 123 msec; p less than 0.001); in 4 patients (22%) it was unchanged; in 1 patient was not defined, being inferior to the atrium E.R.P. We were able to induce a reciprocating tachycardia in 3 patients in the supine position, in 6 patients in the upright position. Electrophysiologic testing in the upright position improves the evaluation of the accessory pathway electrophysiologic properties.

Adolescent↗
PubMed1986

Prognostic relevance of clinical pharmacology of antileukemic drugs.

Response to treatment is the most important prognostic factor in children undergoing treatment for acute lymphoblastic leukemia. Factors that interfere with the pharmacokinetic determinants of anti-leukemic compounds may cause a decreased activity of one or more of the drugs included in the treatment protocol. Noncompliance with the prescribed treatment, individual pharmacokinetic differences, interference with oral drug absorption, and different guidelines for dose reduction related to toxicity are some of the factors responsible for a decreased or variable antileukemic activity which may influence treatment results.

Antineoplastic Agents↗