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Biomedical subjects

G Luzi

Publications and source records attributed to G Luzi.

At least 37 records · Page 2Linked to original sources
PubMed1995

Frequency of provirus-bearing CD4+ cells in HIV type 1 infection correlates with extent of in vitro apoptosis of CD8+ but not of CD4+ cells.

Lymphocytes from HIV-1-infected subjects undergo massive apoptosis when cultured in vitro, and this phenomenon might reflect pathogenetic mechanisms leading to immune dysfunction in vivo. However, (1) lymphocyte death is not restricted to CD4+ cells but seems to involve predominantly CD8+ cells, and (2) the same phenomenon occurs in other viral infections. Furthermore, it is not known whether a relationship exists between the HIV-1 burden and this type of cell death. In this work we sought to determine whether the HIV-1 provirus load correlates with the propensity to apoptosis of CD4+ and CD8+ cells. We studied 10 HIV-1-infected patients with CD4+ cell counts above 500/mm3 and free of concomitant infections. We correlated the frequency of HIV-1-infected CD4+ cells with the extent of culture-induced apoptosis as well as with the phenotype of the apoptotic lymphocytes. We found that the magnitude of apoptosis correlated with the frequency of HIV-1-infected CD4+ cells (p = 0.0007), and that increasing viral load and apoptosis were associated with a shift to the selective death of CD8+ cells. Our data support the view that, in addition to CD4+ cell killing, another immunopathogenic effect of HIV might be that of priming CD8+ cells to apoptosis. In vivo, this could eventually lead to the exhaustion of the cytotoxic T cell compartment.

Adult↗
PubMed1995

Detection of IgM antibodies to human herpesvirus 6 in Romanian children with nonprogressive human immunodeficiency virus disease.

The prevalence of human herpesvirus 6 (HHV-6) infection and the course of human immunodeficiency virus (HIV) disease were investigated in 25 Romanian children with nosocomial HIV-1 infection. HHV-6 IgM and IgG antibodies were detected by enzyme immunoassay (EIA) and immunofluorescence assay (IFA) at the beginning of the study and after 18 months, concomitantly with collection of virologic, immunologic and clinical data. The initial HHV-6 seropositivity was 92% by EIA and 76% by IFA, whereas final testing showed 100% positivity by EIA and 84% by IFA. Positive HHV-6 IgM antibodies were detected in 10 children (40%) by EIA and IFA. Of these 9 children (36%) by EIA and 6 (24%) by IFA had both initial and final IgM antibodies. Children with HHV-6 IgM antibodies had a higher prevalence of pneumonitis than those without (100% vs. 53.3%; P < 0.01). In addition they more frequently showed positive p24 antigen detection (67% vs. 40%) and positive HIV-1 culture (80% vs. 69%). Nevertheless the patients with HHV-6 IgM antibodies showed a slight increase in the final mean CD4+ T cell count (from 1.140 to 1.185 x 10(6)/liter), whereas those with HHV-6 IgG alone showed a statistically significant (P = 0.01) decrease (from 1.395 to 968 CD4+ T-cells x 10(6)/liter). Therefore current or recent HHV-6 infection, as revealed by positive HHV-6 IgM antibodies, appeared to be associated with the development of pneumonitis but not with progression of HIV disease. A possible competitive inhibition of HIV-1 by HHV-6 or a stimulating effect of HHV-6 on CD4+ T-cell production may be suggested.

AIDS-Related Opportunistic Infections↗
PubMed1995

Diagnosis of persistent left superior vena cava by multiplane transesophageal echocardiography.

Persistent left superior vena cava occurs in 2-4% of all congenital cardiac defects. The diagnosis is often missed if the lesion is not accurately looked for. Drainage to the coronary sinus is well tolerated, whereas drainage to the left atrium produces right to left shunt and may be associated with brain abscesses and/or embolization secondary to intravenous therapy administered through the left arm. This paper describes for the first time the diagnosis of persistent left superior vena cava by transesophageal contrast echocardiography. Echocardiography is the method of choice in the diagnosis of persistent left superior vena cava, because it can be used at the patient's bedside and allows easy detection of the drainage site.

Echocardiography, Transesophageal↗
PubMed1994

The role of telemetry in perinatal monitoring.

In the field of transmission and exchange of clinical information particularly good results are foreseen with the development of data telemetry. In perinatal medicine the telemetric technologies are being employed in several situations. It is possible to subdivide the telemetric technologies into short and long distance systems. Short distance telemetry employs devices which utilize radiowaves or laser techniques to transmit data from the original source to centralized equipment; the main application is the transmission of the cardiotocographic signal to permit ambulation of the patient during recording. It may allow fetal heart rate testing to be performed in a setting more acceptable to patients telemetric not be physically confined to a bed or a chair. The telemetric transmission of the cardiotocogram (CTG) may solve problems of organization when the ratio of parturient to midwife exceeds 1:1. Long distance telemetry consists of the telephone transmission of data obtained from distant source to a consultation center where the data can be evaluated, stored and where hospital staff may suggest appropriate decision related to clinical course. In prenatal medicine, the system can offer the monitoring of maternal blood pressure, automatic urine and glucose analyses, surveillance of fetal heart rate and uterine contractions. CTG telemetry has been used with good results for the prevention of preterm labor while blood pressure control by telemetry may be useful for the prevention and management of gestational hypertension. Knowledge by the pregnant woman that it is possible to continuously monitor by telemetric technology her health and the health of her fetus provides reassurance during a delicate period.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1993

Doppler studies of uterine arteries in spontaneous and artificially induced menopausal women.

In the postmenopausal period, women's genital organs undergo several changes and female hormones, as well as modification of vascular reactivity to various stimuli, play a major role in this process. We studied the modification of uterine vascularity consequent to spontaneous or artificially induced menopause, with gonadotropin releasing hormone (GnRH) analogs. Flow velocity waveforms of the uterine arteries were detected using a color Doppler imaging system with a transvaginal probe; the pulsatility index was calculated. The study group consisted of 15 women observed before and after 6 months of treatment with GnRH analogs (triptorelin 3.75 mg depot every 4 weeks intramuscularly) for uterine fibromyomata; 20 women after 5 years of spontaneous menopause; and 20 healthy and normally menstruating women in the late luteal phase. We found a significant difference among the three groups with a progressive increase of the pulsatility index in spontaneous menopausal women. This phenomenon may be due to a different hormonal pattern which exists in spontaneous and artificially induced menopause (increase of gonadotropin level in the former and decrease in the latter), and to a decrease of vascular compliance caused by progressive sclerosis of the vasal walls.

Journal Article↗
PubMed1993

Immunoregulation of autoimmune disorders: the role of intravenous immunoglobulins.

Modified and intact immunoglobulin preparations are available for therapeutic use. The administration of intravenous immunoglobulins (IVI G) gave positive results in Primary Immunodeficiency Syndromes (PIS) (prophylaxis of viral and bacterial diseases), in treatment of secondary immunodeficiencies (hematologic malignancies, bone marrow transplantation), and in some infections. Adverse reactions have been reported during IVIG infusions, but they are rarely serious and do not represent limiting conditions for a short or long term therapy. After the original observation in thrombocytopenic purpura, IVIG have been used as immune modulators in various autoimmune related disorders. Various mechanisms of action are proposed: blockade and down regulation of phagocytic function via Fc receptor, regulation of idiotype-anti idiotype network, suppression of idiotype synthesis, T-B cell interference towards antigen presentation, increase in suppressor lymphocytes, IVIG-cytokine interaction.

Autoimmune Diseases↗
PubMed1993

[Anterograde and retrograde cardioplegia in myocardial revascularization. An intraoperative contrast echographic study].

The aim of this study was to assess the distribution of antegrade and retrograde cardioplegia with intraoperative contrast echocardiography in patients undergoing coronary artery bypass grafting. Fifteen patients with chronic stable angina pectoris and severe coronary artery disease were studied. The severity of coronary artery disease was assessed at coronary angiography, using the Jeopardy Score System. The presence and the extent of collateral circulation was evaluated on the basis of preoperative coronary angiography and graded as: absent or poor; good or excellent. Coronary revascularization was carried out during extracorporeal circulation and myocardial protection was performed with antegrade (aortic root) and retrograde (right atrial) cardioplegia. The echo contrast agent was sterilely prepared 1 hour prior to surgery and consisted of a solution of sonicated 5% human albumin microbubbles. Two ml of sonicated albumin were injected along with antegrade cardioplegia and 4 ml with retrograde cardioplegia. The echocardiographic images were obtained with transesophageal echocardiography in the transgastric left ventricular short-axis view. Images were recorded on videotape for off-line planimetric measurement of percent myocardial opacification. Data were analyzed with the analysis of variance. Multiple comparisons were made with Student's paired t test and using Bonferroni's correction. Myocardial opacification was 58.9 +/- 12.9% during antegrade cardioplegia and 77.5 +/- 16.4% during retrograde cardioplegia (p = 0.003). This overall difference was mainly due to the impact of collateral circulation in the distribution of antegrade cardioplegia. Patients with absent or poor collateral circulation showed a lower degree of myocardial opacification than patients with good or excellent myocardial opacification (44.3 +/- 12.0% versus 64.2 +/- 8.6%; p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1992

Short-term effects of ritodrine, aminophylline and atropine on umbilical artery blood flow velocity waveform.

With the recent introduction of Doppler technology, a non-invasive methodology which enables to evaluate qualitative changes in circulatory vessels, it is possible to investigate the possible effects of various drugs on several parameters of utero-placental-fetal circulation. In the present study we evaluate the flow velocity waveform (FVW) of umbilical artery (UA) during and after administration of aminophylline, atropine and ritodrine to healthy pregnant women. In our study we did not observe any significant short-term variation of PI after the administration of these drugs. Slight variations were detected, and they may be interpreted on the basis of the mode of action of these drugs. Doppler technology may be a useful tool for monitoring some effects on the fetus of the maternal administration of therapeutic agents.

Aminophylline↗
PubMed1992

Absence of antibodies to human herpesvirus-6 in patients with slowly-progressive human immunodeficiency virus type 1 infection.

To evaluate a possible role for Human Herpesvirus-type 6 (HHV-6) coinfection as a co-factor in the progression of HIV-1 disease, we investigated the prevalence of seropositivity for HHV-6 in a cohort of HIV-1 infected patients. These patients were retrospectively divided into two groups according to the decline of CD4+ T cells during the follow up: 11 were classified as rapid decliners (less than 400 CD4+/cmm within 1 year), and 38 as slow decliners (greater than 400 CD4+/cmm after at least 4 years' follow up). HHV-6 antibodies were detected by a commercial immunofluorescence assay and by a Western blotting assay developed in our laboratory. Our results show that Western blot appears to provide results satisfactorily free of false positivities. We found that the frequency of HHV-6 seropositivity was significantly lower in the group of slow decliners, compared both to rapid decliners and to the general population. These data suggest a role for HHV-6 co-infection in the progression of HIV-1 disease.

Adolescent↗
PubMed1992

Parvovirus infection in children with AIDS: high prevalence of B19-specific immunoglobulin M and G antibodies.

OBJECTIVE: Investigation of the prevalence and pathogenic role of parvovirus B19 infection in Italian and Rumanian children with AIDS, compared with age-matched HIV-negative children (controls) with various recurrent infections of unknown aetiology. DESIGN: Detection of B19-specific immunoglobulin (Ig) M and IgG antibodies as the most indicative markers of past or current B19 infection. METHODS: B19 antibodies were detected by two enzyme immunoassays using synthetic peptide or recombinant protein, which corresponded to different B19 epitopes, as coating antigens. RESULTS: B19 IgM and IgG were seen in 10 out of 20 (50%) Italian and in 20 out of 51 (39.2%) Rumanian children with AIDS, in contrast to none out of 17 Italian and one out of 22 Rumanian controls (P less than 0.001). In addition, two Italian controls (11.8%), two Rumanian children with AIDS (3.9%), and two Rumanian controls (9.1%) had B19 IgM alone. Specific IgG alone was detected in eight (40%) Italian and 14 (27.5%) Rumanian children with AIDS, and in seven (41.2%) Italian and four (10.2%) Rumanian controls. CONCLUSIONS: While it is possible to attribute some B19 infections in Rumanian children to blood transfusion, the source was unknown for Italian children. However, in three of the Italian children who had B19 IgM and IgG persistently for 15-22 months, and in a 2-month-old Italian infant with B19 IgM and IgG, HIV might have activated a congenital or perinatally-acquired B19 infection.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Plasma viraemia in seronegative HIV-1-infected individuals.

It has been reported that the period of latency between HIV-1 infection and the production of antibodies against the virus is sometimes prolonged for greater than 6 months. However, the data supporting this are still controversial and it is not known whether these individuals are actually infectious, especially through body fluids. We have performed a prospective study of 65 high-risk HIV-1-antibody-negative individuals who were followed-up for a period of at least 1 year. Twelve of these individuals were shown by polymerase chain reaction (PCR) to be carriers of HIV-1 proviral sequences. The virus was isolated from lymphocytes in five out of 10 PCR-positive subjects and from cell-free plasma in two. Our data indicate that in some cases delayed seroconversions may be associated with productive infection, suggesting that mechanism(s) other than viral latency may be responsible for the absence of antibody responses to HIV-1 proteins.

Blood Cells↗
PubMed1990

Characterization of AIDS-associated tumors in Italy: report of 435 cases of an IVDA-based series.

The Italian Cooperative Group on AIDS-related tumors has collected 435 cases of HIV-associated tumors since December 1986. The following conclusions can be drawn from this IVDA-based series: (1) at least 15% of AIDS cases are associated with tumors; (2) the number of malignant lymphomas (high-grade non-Hodgkin's lymphoma [NHL], Hodgkin's disease [HD] is comparable to that of Kaposi's sarcoma (KS) (188 vs. 198); (3) KS among AIDS patients is less common than in countries where homosexual men are the main group affected by AIDS. However, KS also affects intravenous drug abusers (IVDA) almost exclusively males, with characteristics similar to those observed among homosexual men; (4) HD is associated with an aggressive course; (5) anal and oral primary tumors as well as oral and anal involvement of NHL are very rare; (6) testicular cancers occur in patients mainly with early HIV infection, without adversely affecting the dosage of radiotherapy and chemotherapy; (7) cervical cancer successfully treated with conization suggests that PAP test screening in young IVDA women is warranted; (8) lung cancer occurs in a young age group with rapid progression and death.

Acquired Immunodeficiency Syndrome↗