HCV infective virions can be carried by human platelets

It has been previously demonstrated that platelets (PLTs) can bind and transport HIV-1 infectious virions. Hepatitis C virus (HCV)-HIV-1 co-infection occurs frequently among users of illicit intravenous drugs, thereby increasing the severity of HIV disease and the evolution towards chronic active hepatitis and hepatocellular carcinoma of HCV-related hepatitis. In the present study we investigated whether or not PLTs can carry HCV, and studied the binding mechanisms. Purified PLTs, obtained from healthy donors, HCV negative and HIV negative, were adsorbed with HCV-containing serum and then employed to infect a THP-1 monocytoid cell line. Replication of HCV was observed as shown by positivity for the E2 antigen within THP-1 cells, by indirect immunofluorescence; moreover, HCV-RNA was detected in supernatants of THP-1 cells at day 7 post-incubation with HCV-adsorbed PLTs. The binding of HCV to PLTs seems to involve fibronectin (FN), as already shown in the case of HIV-1. Indeed, treatment with RGD (Gly-Arg-Gly-Asp-Ser), the key oligopeptide of FN binding, inhibits the ability of HCV to be carried by PLTs in infective forms; the same phenomenon occurs with Mabs to FN. Moreover the infection of THP-1 cells seems to increase FN surface expression, as demonstrated by immunofluorescence tests.

Evaluation of the Effects of a Cosmetic Cream on Irritant Contact Dermatitis: Results of a Multicentre Open Trial

The symptoms of irritant contact dermatitis (ICD) are often controlled by topical corticosteroids, which, however, are not suitable for the long-term management owing to the risk of side effects. Moisturizers can be used to prevent ICD and to treat lesions of mild to moderate severity. In this study we want to assess the effectiveness and tolerability of a cosmetic cream (Efaderm® cream), containing a mixture of substances with moisturizing, anti-inflammatory and antioxidant effects ( borago officinalis oil, soy sterol, urea, lithium glycyrrethinate, carbocysteine, tocopheryl acetate, coenzyme Q10, allantoin), in the treatment of ICD. Three hundred and twelve patients with ICD entered the study. ICD was induced by either occupational or non-occupational factors, affected various skin sites, especially the hands, and was characterized by a subacute, recurrent or chronic course in the majority of cases. The cream was applied on lesionai skin twice a day, or more frequently if needed, for approximately 4 weeks. Most patients (n. 179) did not adopt preventive measures (e.g., irritant avoidance, suspension of working activities, use of protective gloves). After treatment, there was a significant improvement (P<0.001) of symptoms and signs of ICD (erythema, scaling/dryness, oozing/crusting, excoriations/fissuring, pruritus/burning), independently on the use of prevention. Patient's assessment of overall effectiveness was positive in the majority of cases.

Limits of a multi-patch SIS epidemic model

We start from a stochastic SIS model for the spread of epidemics among a population partitioned into M sites, each containing N individuals; epidemic spread occurs through within-site ('local') contacts and global contacts. We analyse the limit behaviour of the system as M and N increase to infinity. Two limit procedures are considered, according to the order in which M and N go to infinity; independently of the order, the limiting distribution of infected individuals across sites is a probability measure, whose evolution in time is governed by the weak form of a PDE. Existence and uniqueness of the solutions to this problem is shown. Finally, it is shown that the infected distribution converges, as time goes to infinity, to a Dirac measure at the value x(*), the equilibrium of a single-patch SIS model with contact rate equal to the sum of local and global contacts.

Cervico-vaginal dysplasia--papillomavirus-induced and HIV-1 infection: role of correlated markers for prognostic evaluation

Sexually-transmitted diseases (STD) can facilitate the progression of HIV-1 infection. Among them, as we have previously demonstrated, cervico-vaginal dysplasia-papillomavirus (HPV)-induced, together with HSV-2 co-infection, seems to be correlated with a more evident immunodepression in HIV-positive women, compared with other sexually transmitted diseases. Here we have analysed some of the main correlated markers of HIV-1 infection progression: CD4 + T lymphocyte concentration, CD4 +/CD8 + T cells ratio, HIV-1 RNA loads and haemoglobin (Hb) concentration in 30 HIV-1 positive women co-infected with HPV, and suffering from cervico-vaginal dysplasia, in different stages. In particular, we noticed a positive correlation, evaluated by Spearman's test, between the degree of progression of dysplastic stages (CIN1 --> 3) until invasive carcinoma (IC) and HIV-1 RNA loads (C(s) = +0.78; p < 0.001), and in contrast, a negative correlation between the same stages of progression and respectively CD4 + T cell concentration (C(s) = -0.54; p = 0.01), ratio (C(s) = - 0.63; p = 0.002) and Hb concentration (C(s) = -0.85; p < 0.001). In conclusion, it is important to underline that low levels of Hb generally paralleled the degree of immunodepression. In fact CD4 + T cell levels and ratio positively correlated with Hb concentrations respectively, with C(s) = + 0.83; p < 0.001 and C(s) = + 0.90; p < 0.001. Finally, the most efficacious antiretroviral combined therapy (HAART = Highly Active Antiretroviral Therapy) can improve the above described laboratory parameters in HIV-1/HPV co-infected women and seems to prevent the progression of CIN1 to the following stages of the dysplastic disease.

Seroprevalence study of tick borne encephalitis in Turin province

BACKGROUND

Tick borne encephalitis (TBE) virus is diffused in some European countries and it is transmitted by tick bites. In Italy Isodex ricinus represents the main vector of the infection, that rarely produces the neurologic manifestations, characterising the secondary phase of the same.

METHODS

In Italy TBE has been little studied and this only in the Middle and Northern regions of the country. Seroepidemiological researches were done prevalently on subjects at high risk of tick bite, such as hunters or forest guards and especially in Trentino and Tuscany. No precise information about TBE virus diffusion was disposable in the Piedmont region and particularly in the Susa valley where, before our investigation failed the data about it.

RESULTS

We found that usual hunters and wild boar breeders seem to be particularly exposed to the risk of TBE virus infection, but none neurologic involvement was detected in the anamnesis of the significantly seropositive subjects and also of the borderline ones, that we have studied, despite the limited number of these subjects.

CONCLUSIONS

Nevertheless we hope for a following extension of our case report, also in consideration that rare cases of encephalitis of unknown etiology, are signalled in Piedmont.

Leucine methyl ester is a powerful allosteric activator of the neutral amino acid cotransport system in Bombyx mori larval midgut

We have identified three methyl esters that have a potent stimulatory effect on the cotransport system responsible for the absorption of most essential amino acids in the silkworm Bombyx mori. L-Leucine methyl ester, the most powerful activator, determined a large dose-dependent, K(+)-independent increase of leucine uptake into midgut brush border membrane vesicles. Kinetic experiments revealed non-essential mixed-type activation, with K(a) values of 27+/-2 and 47+/-8 microM in the presence and in the absence of K(+), respectively. The activation increased K(m) twofold, and V(max) up to 18-fold depending upon the experimental conditions. Leucine uptake mediated by the amino acid uniport appears to be unaffected by the activator.

Serum citrate levels, haptoglobin haplotypes and transferrin receptor (CD71) in patients with HIV-1 infection

BACKGROUND

The progression of HIV-1 infection towards its more advanced stages is accompanied by changes in iron metabolism and increased body iron stores.

PATIENTS AND METHODS

Given the ability of HIV to alter iron metabolism, we studied the principal (transferrin system) and alternative (citrate system) iron pathways in a group of 65 HIV-infected patients (symptomatic stage B1-B3) and in a group of 36 healthy seronegative individuals. We determined serum citrate levels, haptoglobin (Hp) haplotypes, expression of transferrin receptor (CD71) on cell lines infected with HIV-1 as well as iron markers including blood iron, transferrin and ferritin.

RESULTS

Our data showed decreased serum citrate levels in the HIV-infected patients compared to controls (92.9 +/- 22.4 microM/l vs 126.2 +/- 29.2 microM/L; p < 0.01). In particular, the serum citrate levels negatively correlated with HIV-1 RNA copy number (mean: 2.53 +/- 1.88 x 10(5)/ml, r(s) = 0.70, p < 0.01) and positively correlated with CD4+ T-lymphocyte count (mean: 241 +/- 168/ml, r(s) = 0.64, p > 0.05). Accordingly, blood iron, transferrin and red cell concentrations were lower in HIV-infected patients compared to the controls, whereas serum ferritin levels were higher in HIV-infected patients. Moreover, the Hp haplotype distribution showed significant differences only in the group of HIV-infected patients (p = 0.02; chi2 test).

CONCLUSION

Our results show that iron metabolism is altered in patients with HIV-1 infection. The alternative pathway (citrate system) is particularly affected, since when citrate levels are low, both aconitase activity and HIV-1 replication need iron.

Human infections tick-transmitted

In this monograph are analysed the principal infections transmitted by ticks and particularly those interesting Europe and North America. Besides the main species of these arthropods are described in consideration of their characteristics and geographic diffusion. In particular the infections caused by Borrelia genus and tick born encephalitis virus are treated more exhaustively in consideration of their potential severity and because the diagnosis of these infections is sometimes difficult. However also the main rickettsial infections transmitted by ticks are reported together the hemorragic fevers transmitted by such arthropods. In particular it is exhaustively analysed the Mediterranean tick fever in consideration of its presence in some regions of Italy and of the wrong opinion of considering this pathology not very severe. Lastly has been included a treatment about some emergent infections transmitted by ticks, like as the ehrlichiosis and babesiasis, but also the mention of tularaemia that can be considered a re-emergent infection, also in consideration of the epidemic focus now present in Kossovo. The above-mentioned pathologies are analysed also as regards the laboratory diagnosis (direct and serologic methods), the therapeutic treatment and the prophilaxis, both directed against the arthropods vectors and that of individual type, employing also some vaccines, when disposable.

Leucine transport in membrane vesicles from Chironomus riparius larvae displays a mélange of crown-group features

Leucine uptake into membrane vesicles from larvae of the midge Chironomus riparius was studied. The membrane preparation was highly enriched in typical brush border membrane enzymes and depleted of other membrane contaminants. In the absence of cations, there was a stereospecific uptake of l-leucine, which exhibited saturation kinetics. Parameters were determined both at neutral (Km 33 +/- 5 microM and Vmax 22.6 +/- 6.8 pmol/7s/mg protein) and alkaline (Km 46 +/- 5 microM and Vmax 15.5 +/- 2.5 pmol/7s/mg protein) pH values. At alkaline pH, external sodium increased the affinity for leucine (Km 17 +/- 1 microM) and the maximal uptake rate (Vmax 74.0 +/- 12.5 pmol/7s/mg protein). Stimulation of leucine uptake by external alkaline pH agreed with lumen pH measurements in vivo. Competition experiments indicated that at alkaline pH, the transport system readily accepts most L-amino acids, including branched, unbranched, and alpha-methylated amino acids, histidine and lysine, but has a low affinity for phenylalanine, beta-amino acids, and N-methylated amino acids. At neutral pH, the transport has a decreased affinity for lysine, glycine, and alpha-methylleucine. Taken together, these data are consistent with the presence in midges of two distinct leucine transport systems, which combine characters of the lepidopteran amino acid transport system and of the sodium-dependent system from lower neopterans.

Sexually transmitted infections and cervicovaginal dysplasia in a cohort of human immunodeficiency virus-positive women in Turin

The correlation between sexually transmitted infections and cervicovaginal dysplasia has been evaluated in a cohort of 135 women who tested positive for human immunodeficiency virus type I (HIV-1) and were admitted to Amedeo di Savoia Hospital of Turin during the years 1997 and 1998 (stages B2 and B3 or C2 and C3). Of these women. 31 presented with sexually transmitted diseases (STDs; mean age, 33.5 +/- 5.9 years). Among them, 14 were affected by cervicovaginal dysplasia of differing severity; human papillomavirus (HPV) infection was found in 13 subjects (10 with cervicovaginal dysplasia). Herpes simplex virus type 2 (HSV-2) infection was detected in six women. Finally, Trichomonas vaginalis and Candida albicans were found in 10 and in 6 patients, respectively. Immunologic and hematologic evaluations were performed in the patients affected by STDs; in 28 patients of our case report unaffected by STDs but of similar ages (34.1 +/- 5.6 years) and stage of infection; and in 20 HIV-negative women unaffected by STDs. A significant reduction among the patients affected by STDs, as compared to those unaffected, was found in the case of white cells, CD4+ T cells, and ratio values (CD4 +/ and CD8 + T cells). Moreover, red cell count and hemoglobin concentration were lower in those women in the STD group. A lack of correlation was found between HIV RNA loads and CD4 + T cell counts and between HIV RNA and hemoglobin concentration in the patients with cervicovaginal dysplasia and in those affected by HSV-2 infection, which differed from the findings in subjects affected only by trichomoniasis or candidiasis. This suggests that the two former pathologic conditions (cervico-vaginal dysplasia and HSV-2 infection), other than HIV- I infection, may contribute to the impairment of these values. Moreover in our case report, T vaginalis and HSV-2 infections, which are suspected to have an oncogenic potential, do not seem to be relevant in the induction or facilitation of genital neoplastic diseases. Noteworthy is that the patients affected by HSV-2 infection, such as those affected by genital neoplastic diseases, showed the most compromised values of total white cells, CD4+ T cells, ratio index, red cells, and hemoglobin concentration.

Differential splicing of the IA-2 mRNA in pancreas and lymphoid organs as a permissive genetic mechanism for autoimmunity against the IA-2 type 1 diabetes autoantigen

Type 1 diabetes results from the autoimmune destruction of pancreatic beta-cells in genetically susceptible individuals. Growing evidence suggests that genetically determined variation in the expression of self-antigens in thymus may affect the shaping of the T-cell repertoire and susceptibility to autoimmunity. For example, both allelic variation and parent-of-origin effects influence the thymic expression of insulin (a known type 1 diabetes autoantigen), and insulin gene transcription levels in thymus inversely correlate with susceptibility in both humans and transgenic models. It is unclear why patients lose tolerance to IA-2 (insulinoma-associated tyrosine phosphatase-like protein, or islet cell antigen 512 [ICA512]), especially because IA-2 polymorphisms are not associated with type 1 diabetes. We report that alternative splicing determines differential IA-2 expression in islets compared with thymus and spleen. Islets express full-length mRNA and two alternatively spliced transcripts, whereas thymus and spleen exclusively express an alternatively spliced transcript lacking exon 13. This encodes for the transmembrane (TM) and juxta-membrane (JM) domains that comprise several type 1 diabetes target epitopes, supporting the concept that tolerance to IA-2 epitopes not expressed in lymphoid organs may not be achieved. We propose differential splicing as a regulatory mechanism of gene expression playing a permissive role in the development of autoimmune responses to IA-2. Our findings also show that candidate gene expression studies can help in dissecting the complex genetic determinants of a multifactorial disease such as type 1 diabetes.

[In vivo and in vitro production of interleukin-1 after febrile convulsions]

Pathogenesis of febrile convulsions (FC) is still unknown, suggested causes include the role of antidiuretic hormone (ADH). ADH is an endogenous antypyretic and his excessive production of the consequent hyponatraemia may be the cause of FC in children with susceptibility to this type of seizure. Whereas, interleukin-1 (IL1) is a pyrogenic substances and is involved in the release of AVP. Helminen et al. have reported a significantly higher production of IL1 in culture of peripheral blood monocytes stimulated with lipopolysaccharide (LPS) of children with FC than in the others with fever but without convulsions. More recently Lahat et al. have compared plasma and cerebrospinal fluid ILI levels of children with FC with those of children with fever but without convulsions, but they did not find significant differences. The aims of this study were to determine the IL1 levels in vivo and in the supernatants of cultures of peripheral blood mononuclear cells (PBMC) stimulated or not with LPS in children with FC and in children with fever without FC and to evaluate the influence of ADH and diazepam (DZ) on IL1 production. Blood samples for PBMC cultures were obtained from 11 children with FC on the hospital admission, (group 1) and after 48 hours from treatment with DZ (group 2). The production of IL1 was measured by RIA in the supernatants of the PBMC stimulated with LPS, LPS + DDAVP (synthetic vasopressin), LPS + DZ and in vivo in plasma samples. The control groups were constituted by 9 children with fever and without convulsions (group 3), 4 of them were studied at the end of fever too (group 4), and finally by 9 children in good health (group 5). No significant differences were observed. These results do not support the hypothesis that increased production of IL1 is involved in the pathogenesis of FC in children.

Differential regulation of Fas-mediated apoptosis in both thyrocyte and lymphocyte cellular compartments correlates with opposite phenotypic manifestations of autoimmune thyroid disease

Several mechanisms are probably involved in determining the evolution of autoimmune thyroid disease (AITD) towards either hypothyroidism and the clinical syndrome known as Hashimoto's thyroiditis (HT) or toward hyperthyroidism and the symptoms of Graves' disease (GD). To gain further insight into such mechanisms we performed an exhaustive comparative analysis of the expression of key molecules regulating cell death (Fas, Fas ligand [FasL], Bcl-2) and apoptosis in both thyrocytes and thyroid infiltrating lymphocytes (TILs) from patients with either GD or HT. GD thyrocytes expressed less Fas/FasL than HT thyrocytes, whereas GD TILs had higher levels of Fas/FasL than HT TILs. GD thyrocytes expressed increased levels of the antiapoptotic molecule Bcl-2 compared to the low levels detected in HT thyrocytes. The opposite pattern was observed in GD (low Bcl-2) and HT (high Bcl-2) TILs. The patterns of apoptosis observed were consistent with the regulation of Fas, FasL, and Bcl-2 described above. Our findings suggest that in GD thyroid the regulation of Fas/FasL/Bcl2 favors apoptosis of infiltrating lymphocytes, possibly limiting their autoreactive potential and impairing their ability to mediate tissue damage. Moreover, the reduced levels of Fas/FasL and increased levels of Bcl-2 should favor thyrocyte survival and favor the thyrocyte hypertrophy associated with immunoglobulins stimulating the thyrotropin (TSH) receptor. In contrast, the regulation of Fas/FasL/Bcl2 expression in HT promotes thyrocyte apoptosis, tissue damage, and a gradual reduction in thyrocyte numbers leading to hypothyroidism. These findings help define key molecular mechanisms contributing to the clinical outcome of thyroid autoimmunity.

Self-antigen-presenting cells expressing diabetes-associated autoantigens exist in both thymus and peripheral lymphoid organs

Recent reports indicate that genes with tissue-restricted expression, including those encoding the type 1 diabetes autoantigens insulin, glutamic acid decarboxylase (GAD), and the tyrosine-phosphatase-like protein IA-2 (or ICA512), are transcribed in the thymus. The reported modulation of diabetes susceptibility by genetically determined differences in thymic insulin levels and studies in transgenic mice provide correlative and functional evidence that thymic expression of peripheral proteins is crucial for immunological self-tolerance. However, there are no specific data about the existence, tissue distribution, phenotype, and function of those cells that express insulin and other self-antigens in the human thymus. We find that the human thymus harbors specialized cells synthesizing (pro)insulin, GAD, and IA-2, mainly localized in the medulla, and we demonstrate such cells also in peripheral lymphoid organs (spleen and lymph nodes). Phenotypic analysis qualifies these cells as antigen-presenting cells (APCs), including both dendritic cells and macrophages. These cells often appear surrounded by apoptotic lymphocytes, both in thymus and spleen, and may therefore be involved in the deletion of autoreactive lymphocytes. Our findings demonstrate the existence of, and define the tissue distribution and phenotype of, a novel subset of APCs expressing self-antigens in human lymphoid organs that appear to be involved in the regulation of self-tolerance throughout life.

Human herpesvirus 8 and associated diseases in a group of 67 human immunodeficiency virus-seropositive individuals

Human herpesvirus 8 (HHV-8) is involved in the pathogenesis of Kaposi's sarcoma, of B-cells lymphomas, and of Castelman's disease. However, the role of this virus is not yet well known. To investigate the relationship between HHV-8 infection and diseases correlated with human immunodeficiency virus (HIV), we studied a cohort of 67 HIV-seropositive subjects, some of them coinfected with HHV-8. An indirect immunofluorescence test was employed to detect the antibodies against this virus. Positive cases were 31 (46.3%); among the 67 patients, 14 were weakly positive, or + (20.9%); 11 were significantly positive, or ++ (16.4%); and 6 were strongly positive, or (8.9%). These last six patients were the most affected by opportunistic infections, and all were affected by neoplastic pathologies. Moreover, the HHV-8 positive subjects showed hematologic and martial alterations more severe than those in the negative subjects. HHV-8 seroprevalence in HIV-seropositive patients of our cohort was higher (46.3%) than in normal population (0-10%). The presence of disseminated Kaposi's sarcoma and other neoplasms associated with high HIV-RNA levels in HHV-8-positive patients, and particularly in those with strong positivity, corroborates the hypothesis that the virus is correlated with the progression of HIV infection and with its related diseases, especially those that are neoplastic. Last, the severe alterations of iron metabolism found in the patients coinfected with HHV-8 and the negative effect of this virus on the lymphocytic populations can contribute to the unfavorable evolution of HIV infection and also might facilitate tumor development.

Levels of the bcl-2 protein, fibronectin and alpha(5)beta(1) fibronectin receptor in HIV-1-infected patients with Kaposi's sarcoma

Kaposi's sarcoma (KS) is an angioproliferative disease characterized by proliferation of neoplastic cells (spindle cells) mixed with endothelial and inflammatory cells. In this study we evaluated the role of the adhesive glycoprotein, fibronectin (FN) and its receptor alpha(5)beta(1) (FNR), and the proto-oncogene bcl-2, an anti-apoptotic protein. Significantly decreased serum levels of FN were noted in HIV-1-infected patients with KS, whereas serum levels of FNR were significantly increased in the same patients. Furthermore, increased FNR expression was observed on CD4 cells from KS patients. Serum levels of bcl-2 protein were significantly decreased in asymptomatic seropositive patients, whereas HIV-1-infected patients with KS showed increased serum levels of bcl-2. These results provide further information about interaction between integrins and the extracellular matrix and bcl-2 protein that can support cell survival either of neoplastic cells or endothelial and inflammatory cells.

Candida albicans and HIV-1 Infection

Candida albicans virulence is in part mediated by fibronectin (FN) interaction. We compared the adherence level to FN (using Becton Dickinson FN-coated plates) of several strains of yeast isolated from HIV-1 infected or uninfected subjects affected by candidiasis (30 strains from HIV+ subjects and 18 from HIV- subjects). More adhesive strains were found in HIV+ patients than in HIV- subjects. In particular a mean increase of 120 per cent as regards the total number of adhesive cells and 230 per cent as regards the adhesive cells producing germ tubes was detected in the former group of strains as compared to the latter ( p < 0.001 in both cases). The enhancement of FN expression induced by HIV-1 infection, as we have previously demonstrated, can increase interest in the adherence to FN of C. albicans strains isolated from AIDS-affected patients. Moreover, we also underline the important role played by HIV Nef protein in increasing the C. albicans aggressiveness. In fact a significant inhibitory effect of Nef on the phagocytosis of this yeast by macrophages has been demonstrated and the oxidative processes of these cells seem to be down-regulated by this protein.

Multifunctional activity of recombinant p14 on lymphoid cell cultures

Some effects of recombinant p14, a protein encoded by the tat gene of immunodeficiency virus type 1 (HIV-1), were investigated on T lymphocytic cell cultures. In particular, we detected p14 adsorption to cells, the rate of cell replication, the expression of fibronectin (FN) and its receptor (FNR) and of cell surface CD4 antigen in HIV-1-infected or uninfected MT-4 and H9 cells, treated with p14. Moreover, we evaluated the proportion of apoptotic cells in uninfected and chronically infected H9 cells in the presence of p14 and the modulation of interferon (IFN) production induced by p14 in PBMC of healthy subjects. The results obtained demonstrate that p14 exerts multifunctional activities on HIV-1 infected and uninfected cells. In particular, this protein interacts in a specific manner with cell surface, especially with that of infected cells, and enhances the expression of FN and FNR but not that of the CD4 lymphocyte antigen. Moreover, p14 increases cell replication, IFN production and can exert a slight modulation of apoptosis. We also propose a model to explain a possible role in HIV-1 infection of the effects of exogenous p14.

Inhibition of Fas-mediated apoptosis in mouse insulinoma betaTC-3 cells via an anti-Fas ribozyme

In this study we have designed and constructed an anti-Fas ribozyme and show that it can specifically cleave the Fas mRNA in vitro. Moreover, to test its efficacy ex vivo, we transfected the anti-Fas ribozyme into betaTC-3 insulinoma cells, using a RNA polymerase III promoter to drive its expression. Like pancreatic beta cells, betaTC-3 cells do not constitutively express Fas, but Fas expression can be induced with IL-1 and IFN-gamma. Transfected cells expressed an average of 5000 copies of anti-Fas ribozyme transcript per cell as assessed by reverse transcriptase-real-time PCR. After IL-1/IFN-gamma treatment, betaTC-3 cells transfected with the anti-Fas ribozyme expressed 80% less Fas compared with mock-transfected cells. In addition, the anti-Fas ribozyme also inhibited Fas expression in NIT-1 insulinoma cells and in primary cultures of dispersed pancreatic islet cells. Inhibition of de novo Fas expression in betaTC-3 cells expressing the anti-Fas ribozyme correlated with resistance to Fas-mediated apoptosis as determined by the number of cells exhibiting caspase 3 proteolytic activity. Hence, we have engineered a ribozyme capable of preventing Fas expression in the betaTC-3 pancreatic insulinoma cell line and conferring resistance to Fas-mediated apoptosis. We suggest that ribozymes may be potentially useful to engineer resistance to apoptosis in transplantable beta cells, a feature that may significantly improve the survival of islet cell grafts.

Impact of highly active antiretroviral therapy in HIV-positive patients with cardiac involvement

OBJECTIVES

Cardiac involvement is frequently observed in HIV-infected patients, especially in those in the late stage of the disease. This study was designed to evaluate the impact of highly active antiretroviral therapy (HAART) in patients with cardiac involvement.

METHODS

A retrospective study of 1042 patients admitted to a Division of Infectious Diseases between 1989 and 1998. During the period 1989-1995, 544 patients were treated with nucleoside reverse transcriptase inhibitors (NRTI), whereas 498 patients were treated with HAART during the period 1996-1998.

RESULTS

Cardiac involvement, including arrhythmias, pericarditis, ischaemia, dilated cardiomyopathy, endocarditis, pulmonary hypertension, and myocarditis were observed in 282 of 544 (51.8%) patients treated with NRTI, compared with 93 of 498 (18.6%) patients with HAART (P < 0.0001).

CONCLUSIONS

HAART has significantly decreased the incidence of cardiac involvement, especially pericarditis, arrhythmias, and dilated cardiomyopathy.