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M Marroni

Publications and source records attributed to M Marroni.

At least 19 recordsLinked to original sources
PubMed2001

Mechanisms of glucose transport at the blood-brain barrier: an in vitro study.

How the brain meets its continuous high metabolic demand in light of varying plasma glucose levels and a functional blood-brain barrier (BBB) is poorly understood. GLUT-1, found in high density at the BBB appears to maintain the continuous shuttling of glucose across the blood-brain barrier irrespective of the plasma concentration. We examined the process of glucose transport across a quasi-physiological in vitro blood-brain barrier model. Radiolabeled tracer permeability studies revealed a concentration ratio of abluminal to luminal glucose in this blood-brain barrier model of approximately 0.85. Under conditions where [glucose](lumen) was higher than [glucose](ablumen), influx of radiolabeled 2-deoxyglucose from lumen to the abluminal compartment was approximately 35% higher than efflux from the abluminal side to the lumen. However, when compartmental [glucose] were maintained equal, a reversal of this trend was seen (approximately 19% higher efflux towards the lumen), favoring establishment of a luminal to abluminal concentration gradient. Immunocytochemical experiments revealed that in addition to segregation of GLUT-1 (luminal>abluminal), the intracellular enzyme hexokinase was also asymmetrically distributed (abluminal>luminal). We conclude that glucose transport at the CNS/blood interface appears to be dependent on and regulated by a serial chain of membrane-bound and intracellular transporters and enzymes.

Animals↗
PubMed2001

[Importation dengue].

We describe two cases of dengue fever (DF) serologicaly confirmed. In both, the clinical features are characterized by: fever, severe headache, myalgias and arthalgias, transient macule-papule rash, leukopenia and thrombocytopenia. The entire illness last few days and terminates abruptly without therapy. A history of travel to dengue-endemic areas and occurrence of other cases in a community are important reminders to include this disease in the differential diagnosis. The hemoagglutination inhibition test for DF at the Laboratory of Virology of the Istituto Superiore di Sanità on two collected sera, during the acute and convalescent phases, has showed a seroconversion. A problem is to advise patients to avoid endemic areas because the second exposure could induce DHF/dengue shock syndrome.

Adult↗
PubMed2000

Detrimental effects of high-dose dexamethasone in severe, refractory, HIV-related thrombocytopenia.

OBJECTIVE: To report a case of HIV-related thrombocytopenia in which high-dose dexamethasone was ineffective and immunologically detrimental. CASE SUMMARY: A 39-year-old white man with persistent, severe, HIV-1-related thrombocytopenia was admitted for epistaxis, bleeding gums, petechiae, and bruising. Previous unsuccessful attempts to reverse the thrombocytopenia included zidovudine, prednisone, vincristine, interferon alfa, and intravenous immune globulins. Based on previous anecdotal reports of the effectiveness of high-dose dexamethasone in refractory, HIV-related thrombocytopenia, we instituted treatment with intravenous dexamethasone 40 mg/d for four sequential days every 28 days. After three cycles of therapy, the platelet count remained < 15 x 10(9)/L; however, the CD4+ lymphocyte count decreased progressively from 1447 x 10(6)/L at baseline to 560 x 10(6)/L three months after the third cycle. Due to persistent, severe thrombocytopenia and bleeding, the patient underwent splenectomy, resulting in normalization of the platelet count. DISCUSSION: High-dose dexamethasone has been proposed as treatment for patients with immune thrombocytopenia as an alternative to chronic oral corticosteroids and claimed to be associated with better effectiveness and fewer adverse effects. The results of this treatment in our patient show that this regimen may not only be ineffective, but may also be immunologically detrimental in HIV-infected patients. Although the deterioration of the immunologic status of our patient cannot be fully attributed to high-dose dexamethasone based on the Naranjo scale, the previous long-lasting stability of CD4+ cells and the temporal relationship of a decrease in the CD4+ cell count coinciding with administration of high-dose dexamethasone suggest a causative role of the treatment. CONCLUSIONS: A possible cause-effect relationship between the treatment and the decrease in the CD4+ cell count suggests that the use of high-dose dexamethasone may not be justified in patients with severe, HIV-related thrombocytopenia.

Adult↗
PubMed1999

Prospective, randomized, double-blind trial comparing teicoplanin and cefazolin as antibiotic prophylaxis in prosthetic vascular surgery.

To compare efficacy, tolerability, and cost of antibiotic prophylaxis with teicoplanin and cefazolin in clean prosthetic vascular surgery, a randomized, prospective, double-blind study was performed at the Vascular Surgery Unit of a tertiary-care university hospital. Two-hundred thirty-eight consecutive patients undergoing elective, clean, abdominal or lower-limb prosthetic vascular surgery were allocated to receive a single intravenous dose of teicoplanin (400 mg) or cefazolin (2 g) at the induction of anesthesia. Surgical-site infections occurred in 5.9% of teicoplanin recipients (4.2% wound infection, 1.7% graft infection) and 1.7% of cefazolin recipients (1.7% wound infection, 0% graft infection) (P=0.195). Other postoperative infections occurred in 10% of teicoplanin recipients (pneumonia 7%, urinary tract infection 3%) and 12% of cefazolin recipients (pneumonia 7%, urinary tract infection 2.5%, bloodstream infections 2.5%). Overall mortality rate was 3.4% in teicoplanin recipients (4 patients) and 2.5% in cefazolin recipients (3 patients). Infective deaths occurred in one patient for each group. The two prophylactic regimens were well tolerated. Cost savings of US $52,510 favoring cefazolin were related to the lower acquisition cost (US $1034 vs US $4740) and to the shorter duration of the hospital stay (1762 days vs 1928 days). Cefazolin can still be regarded as the drug of choice for prophylaxis in clean vascular surgery.

Aged↗
PubMed1996

High-dose fluconazole therapy for cryptococcal meningitis in patients with AIDS.

Fluconazole (800-1,000 mg i.v.) was administered to 14 consecutive patients with AIDS and cryptococcal meningitis. At 10 weeks the rate of clinical success was 54.5% (six of 11 patients responded to fluconazole); the Kaplan-Meier estimate of the response rate was 67.1%, and the overall mortality rate was 18.2% (two of 11 patients died). At the end of treatment, eight (72.7%) of 11 patients responded to fluconazole. The median time to the first negative cerebrospinal fluid (CSF) culture was 33.5 days (95% confidence interval, 18.3-67.3); the median time for patients with initial CSF cryptococcal antigen titers of > or = 1:1,024 was 66 days compared with 18 days for patients with initial CSF cryptococcal antigen titers of < 1:1,024 (P = .06). The median time to the first negative CSF culture for patients with an isolate for which the minimum inhibitory concentration (MIC) was 4 micrograms/mL was 56 days compared with 16 days for patients with an isolate for which the MIC was < 4 micrograms/mL (P = .11). The mean serum and CSF levels of fluconazole at steady state were 42.47 +/- 26.31 micrograms/mL and 36.63 +/- 21.08 micrograms/mL, respectively (ratio of CSF:serum, 0.86). No treatment was interrupted and no dose was tapered because of side effects. High-dose fluconazole might be an effective and well-tolerated therapeutic option for patients with AIDS and acute cryptococcal meningitis.

AIDS-Related Opportunistic Infections↗
PubMed1996

[Tuberculosis and immigrants. A study of its prevalence in the Umbria region].

In 1995, 463 patients were admitted in the medical service of Perugia (Sanitary District n. 6). Only 20% of them were enrolled in the TBC programme. Mantoux was: < 10 mm in 35%, 10-15 mm in 25%, > 15 mm in 40%. Chest Rx in 30 subjects demonstrated: normality in 19; old TBC in 7, active TBC in 4 (miliary, bilateral upper lobe pneumonitis, left subapical upper lobe pneumonitis and right lobitis of the upper lobe). All patients were admitted in hospital and showed positive sputum culture for Mycobacterium Tuberculosis. They were treated with isoniazid, rifampin, pyrazinamide, ethambutol/streptomycin for 2 months and with isoniazid, rifampin for other 4-8 months. Two patients showed Mycobacterium tuberculosis with isoniazid resistance. Seven patients were treated with isoniazid chemoprophylaxis without side effects. Migrants should receive information about health care service and be encourage to register themselves with a general practitioner. Skin test screening and chest radiographs for those with positive results should be provided at a convenient location.

Adolescent↗
PubMed1995

Thrombocytopenia in HIV infected patients. Prevalence and clinical spectrum.

We studied the prevalence, clinical spectrum and epidemiologic features of thrombocytopenia among 442 (333 male, 109 female) HIV infected patients. Thrombocytopenia was defined as a platelet count < 100,000/mmc and severe if platelet count was < or = 30,000/mmc. Intravenous drug abusers were 83% (369/442). At the first clinical evaluation according to Walter-Reed (WR) classification, 90% (396/442) of patients were in stage 1-5 and 10% (45/442) in stage 6. Severe thrombocytopenia (platelet count < or = 30,000/mmc) was present in 24% (11/45) of the entire thrombocytopenic population. Forty percent (18/45) of the thrombocytopenic patients were positive to: HBV (6), HCV (7), HBV+HCV (5). Mild bleeding was present in 16% (7/45) of the patients but one case, with severe thrombocytopenia, died of intracranial hemorrhage. Major hemorrhagic sequelae with even fatal events are possible, especially when a low platelet count is associated with other hemostatic abnormalities (e.g. haemophilia, liver disease, disseminated intravascular coagulation). Zidovudine therapy (range 500-1250 mg/day) is effective in normalizing the platelet count (platelets > 100,000/mmc) only in 29% (9/31) of the patients.

Adult↗
PubMed1994

Interferon-alpha is effective in the treatment of HIV-1-related, severe, zidovudine-resistant thrombocytopenia. A prospective, placebo-controlled, double-blind trial.

OBJECTIVE: To determine the effect of interferon-alpha for severe, zidovudine-resistant, HIV-1-related thrombocytopenia. DESIGN: Prospective, randomized, double-blind, placebo-controlled, multicenter, crossover trial. SETTING: Outpatient clinics in Central Northern Italy. PATIENTS: 15 sequential patients positive for HIV-1 with platelet counts less than 25 x 10(9)/L who were refractory to 1 month of full-dose (1000 mg/d) zidovudine. INTERVENTION: Interferon-alpha (3 million units) or placebo (1 mL saline) three times a week subcutaneously for 4 weeks, followed by a 4-week washout period. Patients were then switched to the alternative treatment for the next 4 weeks, followed by another 4 weeks of washout, and they were randomly assigned to either sequence of treatment. Patients received zidovudine (200 mg three times daily) throughout the study. MEASUREMENTS: The primary end point was the platelet count (measured weekly). Secondary end points were qualitative assessment of the platelet response; bleeding time; p24 antigen in serum; CD4/CD8 counts; beta 2-microglobulin in serum; and platelet-associated IgG. RESULTS: Interferon-alpha significantly increased platelet counts in the 12 patients who completed the study (baseline level, 15.6 +/- 7.1 x 10(9)/L; after 4 weeks of interferon-alpha therapy, 82.2 +/- 52.2 x 10(9)/L). The estimated increase in the platelet count after interferon-alpha compared with placebo was 60.0 x 10(9)/L (95% CI, 23.2 to 96.8 x 10(9)/L). The increase was already statistically significant after 3 weeks (66.6 +/- 49.7 x 10(9)/L) and remained significantly increased 1 week after discontinuing interferon-alpha therapy (58.2 +/- 45.0 x 10(9)/L). Placebo did not modify the platelet count. The bleeding time was significantly shortened by interferon-alpha. Four of 12 patients who had more serious alterations of some measures reflecting disease severity did not respond to interferon-alpha. No relevant side effects were observed. CONCLUSIONS: Interferon-alpha is a safe and effective treatment for zidovudine-resistant, HIV-related thrombocytopenia.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Enterocytozoon bieneusi detection in a patient with human immunodeficiency virus infection and chronic diarrhoea: response to albendazole treatment.

Diarrhoea is a common symptom among HIV-infected subjects. An infective cause is often missed. However, more recent knowledge about pathogens has led to the identification of newly recognized unusual microorganisms, such as Microsporidia. We report a case of infestation with these agents in an HIV-infected subject with chronic diarrhoea.

AIDS-Related Opportunistic Infections↗