Latent tuberculous infection among foreign-born individuals applying to shelters in the metropolitan area of Milan.

SETTING: Screening for latent tuberculous infection (LTBI) of groups at high risk of active tuberculosis (TB) is a key component of the End TB Strategy. OBJECTIVE: To conduct a retrospective descriptive analysis of LTBI rates among foreign-born individuals applying to shelters in the metropolitan area of Milan, Italy. DESIGN: All foreign-born individuals registering for accommodation centres in the city of Milan from November 2009 to April 2017 were screened for active TB and LTBI. Individuals aged <36 years with a tuberculin skin test (TST) induration of >10 mm were offered confirmatory testing with QuantiFERON®-TB Gold In-Tube (QFT-GIT). RESULTS: Of the 2666 TST-positive migrants aged <36 years who underwent LTBI confirmation testing, 1322 (49.6%) tested negative, 1339 (50.2%) were positive and five (0.2%) had indeterminate results. In the multivariate analysis, TB incidence in the country of origin and age were significantly associated with QFT-GIT positivity. Although estimated TB incidence in Eritrea, Morocco and Romania was 100/100 000 person-years (py), the probability of being QFT-GIT-positive in individuals from these countries were not statistically significantly different from individuals from countries with TB incidence > 250/100 000 person-years. CONCLUSION: Our data showed a high proportion of LTBI among individuals coming from intermediate TB burden countries.

Regional water quality patterns in an alluvial aquifer: direct and indirect influences of rivers.

The influence of rivers on the groundwater quality in alluvial aquifers can be twofold: direct and indirect. Rivers can have a direct influence via recharge and an indirect one by controlling the distribution of fine-grained, organic-carbon rich flood deposits that induce reducing conditions. These direct and indirect influences were quantified for a large alluvial aquifer on the Swiss Plateau (50km(2)) in interaction with an Alpine river using nitrate as an example. The hydrochemistry and stable isotope composition of water were characterized using a network of 115 piezometers and pumping stations covering the entire aquifer. Aquifer properties, land use and recharge zones were evaluated as well. This information provided detailed insight into the factors that control the spatial variability of groundwater quality. Three main factors were identified: (1) diffuse agricultural pollution sources; (2) dilution processes resulting from river water infiltrations, revealed by the δ(18)OH2O and δ(2)HH2O contents of groundwater; and (3) denitrification processes, controlled by the spatial variability of flood deposits governed by fluvial depositional processes. It was possible to quantify the dependence of the nitrate concentration on these three factors at any sampling point of the aquifer using an end-member mixing model, where the average nitrate concentration in recharge from the agricultural area was evaluated at 52mg/L, and the nitrate concentration of infiltrating river at approximately 6mg/L. The study shows the importance of considering the indirect and direct impacts of rivers on alluvial aquifers and provides a methodological framework to evaluate aquifer scale water quality patterns.

Efficacy and safety of long-term ezetimibe/simvastatin treatment in patients with familial hypercholesterolemia.

AIM: Patients with heterozygous familial hypercholesterolemia (FH) have an increased risk of premature myocardial infarction, stroke, and surgical revascularization, and an increased rate of progression of carotid intima-media thickness (IMT). The most commonly used drugs for cholesterol lowering, statins, have a limited action in these patients. Ezetimibe, a novel compound, selectively inhibits cholesterol uptake and when associated with statins has an additional low-density lipoprotein cholesterol (LDL-C) reducing effect. The aim of this study is to evaluate the effects of long-term combined Ezetimibe/Simvastatin (EZE/SIMVA) therapy (30 months) on the lipidic pattern, inflammatory markers, and carotid IMT in patients with FH subdivided into two groups: one with a history of acute myocardial infarction (IMA) and the other with carotid atherosclerotic plaques but no history of cardiovascular events. METHODS: All patients enrolled in this study (group A: patients with a history of IMA; group B, patients with carotid lesions but no history of cardiovascular events) were submitted to a 6-week period of isocaloric diet and to a 4-week lipid-lowering wash-out period before study entry. After the wash-out period at baseline (time 0) and then every two months total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), and apolipoprotein B and A1 were determined. LDL-C levels were calculated. Fibrinogen and hs-CRP at baseline and at 6, 18, and 30 months were determined. All patients were submitted to an ultrasonographic evaluation of the carotid intima-media thickness at baseline, 18 and 30 months. The scheduled duration time of the study was 30 months. At the beginning of the study all patients were assigned to receive the combined EZE/SIMVA treatment 10/20 mg per day. After two months, patients who had not reached the respective LDL-C targets proposed by NCEP ATPIII (<70 mg/dL for patients with a history of IMA and <100 mg/dL for patients with carotid lesions) were assigned to receive EZE/SIMVA 10/40 mg per day and, after four months, patients who had not reached the respective LDL-C targets were assigned to receive EZE/SIMVA 10/80 mg per day. RESULTS: At the end-point, significant reductions (P<0.001) of about 70% in LDL-C, of 57% in total cholesterol (TC), of 46% in Apo-B, and of 46% in hs-C-reactive protein (hs-CRP) were observed in both groups compared to baseline. Also, triglyceride and fibrinogen levels were significantly (P<0.01) reduced, respectively by 26% and 15% compared to baseline. The EZE/SIMVA association resulted in significant increases in HDL-C (P<0.01) of 11% and in Apo-A1 (P<0.05) by 9% and in significant (P<0.001) reductions of the mean of the carotid IMT in both groups. The EZE/SIMVA treatment was generally well-tolerated, with a safety profile on laboratory parameters. During the 30-month scheduled period of the study, no patient in either group presented any further cardiovascular events. CONCLUSION: In patients with FH, combined EZE/SIMVA treatment resulted in a significant LDL-C lowering, achieving the goals proposed by NCEP ATP III, in a significant improvement of all the lipidic and inflammatory patterns, and above all in a progressive decrease of the carotid IMT. Although the results of ongoing randomized controlled trials are required before making any definitive conclusions, our results support the hypothesis of stabilizing effect of EZE/SIMVA on the atherosclerotic disease both in primary and in secondary prevention.

[Salivary stones and stenosis. A comprehensive classification]. / Lithiases et sténoses salivaires. Une classification pratique des pathologies non tumorales.

INTRODUCTION: Sialendoscopy and sialo-MRI enable diagnosis of salivary gland obstructive pathologies, such as lithiasis, stenosis and dilatations. Therefore, a classification of these pathologies is needed, allowing large series comparisons, for better diagnosis and treatment of salivary pathologies. MATERIAL AND METHODS: With help from people from the European Sialendoscopy Training Center (ESTC), the results of sialographies, sialoMRI and sialendoscopies, a comprehensive classification of obstructive salivary pathologies is described, based on the absence or presence of lithiasis (L), stenosis (S) and dilatation (D) ("LSD" classification). DISCUSSION: It appears that a classification of salivary gland obstructive pathologies should be described. We hope it will be widely used and of course criticized to be improved and to compare the results of salivary gland diagnostic methods, such as sialography and sialendoscopy and also the results and indications for salivary gland therapeutic methods, such as lithotripsy, sialendoscopy and/or open surgery.

Salivary stones and stenosis. A comprehensive classification.

INTRODUCTION: Sialendoscopy and sialoMRI enables diagnosis of salivary gland obstructive pathologies, such as lithiasis, stenosis, and dilatations. Therefore, a classification of these pathologies is needed, allowing large series comparisons, for better diagnosis and treatment of salivary pathologies. MATERIAL AND METHODS: With help from people from the European Sialendoscopy Training Center (ESTC), the results of sialographies, sialoMRI and sialendoscopies, a comprehensive classification of obstructive salivary pathologies is described, based on the absence or presence of lithiasis (L), stenosis (S), and dilatation (D) ("LSD" classification). DISCUSSION: It appears that a classification of salivary gland obstructive pathologies should be described. We hope it will be widely used and of course criticized to be improved and to compare the results of salivary gland diagnostic methods, such as sialography and sialendoscopy, and also the results and indications for salivary gland therapeutic methods, such as lithotripsy, sialendoscopy, and/or open surgery.

One-year atorvastatin treatment in hypercholesterolemic patients with or without carotid artery disease.

AIM: Statins are the drugs of choice in heterozygous familial hypercholesterolemia (FH), which has a high risk of premature cardiovascular events including myocardial infarction, stroke, and surgical revascularization. METHODS: A 1-year open-label study was conducted to test the efficacy and tolerability of Atorvastatin titrated to the target, in proven FH patients and to evaluate certain inflammatory parameters. One hundred and two FH patients (44 men and 58 women; mean age 58.7+/-3.6 years) were included in the study. After evaluation using the B-mode duplex scanning system of extracranial carotid arteries, the patients were divided into two groups: Group 1 (15 men, 25 women) with carotid plaques or intima-media thickness (IMT) greater than 0.95 mm and Group 2 (30 men, 32 women) without carotid plaques or IMT less than 0.95 mm. After a 6-week hypolipemic diet phase all the patients were treated with atorvastatin titrated to achieve a low density lipoprotein (LDL-C) <100 mg/dL. Patients with carotid lesions were also submitted to an oral fixed dose of aspirin 100 mg/day. RESULTS: In patients without and with carotid lesions, atorvastatin treatment (mean dosage: 23.5 mg/day) reduced triglycerides by 8.7% (P<0.005) and 10.6% (P<0.005), total cholesterol by 41.5% (P<0.005) and 42.6% (P<0.005), LDL-C by 55.8% (P<0.005) and 57.3% (P<0.005) and apolipoprotein B by 38.3% (P<0.005) and 37.2% (P<0.005) respectively, and increased the mean levels of high density lipoprotein cholesterol (HDL-C) by 8.7% (P<0.005) and 11% (P<0.005), and apolipoprotein A-I by 3.2% (P<0.05) and 3.3%, respectively. In both groups of patients the mean decrease (52 weeks) of fibrinogen was 19.8% (P<0.005) and 10.4% (P<0.005), respectively and of high sensitivity C-reactive protein (hs-CRP), 36.2% (P<0.005) and 38.2% (P<0.005), respectively. No variation of the parameters of safety and clinical tolerability of the drugs administered was observed. No variation in hematocrit in the patients taking ASA treatment was observed. CONCLUSIONS: In FH patients, 1-year atorvastatin treatment titrated to the target (LDL-C <100 mg/dL) was well tolerated and improved serum lipid levels and inflammatory parameters.

Effects of moderate Sicilian red wine consumption on inflammatory biomarkers of atherosclerosis.

OBJECTIVE: The aim of the study is to evaluate the effect of moderate Sicilian red wine consumption on cardiovascular risk factors and, in particular, on some inflammatory biomarkers. METHODS: A total of 48 subjects of both sexes who were nondrinkers or rare drinkers of moderate red wine were selected and randomly subdivided into two groups assigned to receive with a crossover design a Sicilian red wine (Nero d'Avola or Etna Torrepalino) during meals: Group A (n = 24), in whom the diet was supplemented for 4 weeks with 250 ml/day of red wine, followed by 4 weeks when they returned to their usual wine intake; and Group B (n = 24), in whom the usual wine intake was maintained for 4 weeks, followed by 4 weeks when the diet was supplemented with 250 ml/day of red wine. The following were values measured in all tests: blood glucose, total and HDL-cholesterol and triglycerides, LDL-cholesterol, LDL/HDL ratio, apolipoproteins A1 and B, Lp(a), plasma C-reactive protein, TGFbeta1, D-Dimer, Factor VII , PAl Ag, t-PA Ag, fibrinogen, oxidized LDL Ab, total plasma antioxidant capacity. RESULTS: At the end of the red wine intake period, LDL/HDL, fibrinogen, factor VII, plasma C-reactive protein and oxidized LDL Ab were significantly decreased, while HDL-C, Apo A1,TGFbeta1, t-PA, PAI and total plasma antioxidant capacity were significantly increased. CONCLUSIONS: Our results show a positive effect of two Sicilian red wines on many risk factors and on some inflammatory biomarkers, suggesting that a moderate consumption of red wine in the adult population is a positive component of the Mediterranean diet.

Structure-based design of a dimeric RNA-peptide complex.

The arginine-rich RNA-binding domain of bovine immunodeficiency virus (BIV) Tat adopts a beta-hairpin conformation upon binding to the major groove of BIV TAR. Based on its NMR structure, we modeled dimeric arrangements in which two adjacent TAR sites might be recognized with high affinity by a dimeric peptide. Some dimeric RNAs efficiently bound two unlinked BIV Tat peptides in vitro, but could not bind even one monomeric peptide in vivo, as monitored by transcriptional activation of human immunodeficiency virus long terminal repeat reporters. Results with additional reporters suggest that extending the RNA helix in the dimeric arrangements inhibits peptide binding by decreasing major groove accessibility. In contrast, a dimeric peptide efficiently bound an optimally arranged dimeric TAR in vivo, and bound with an affinity at least 10-fold higher than the monomeric peptide in vitro. Mutating specific nucleotides in each RNA 'half-site' or specific amino acids in each beta-hairpin of the dimeric peptide substantially decreased binding affinity, providing evidence for the modeled dimer-dimer interaction. These studies provide a starting point for identifying dimeric RNA-protein interactions with even higher binding affinities and specificities.

[A rare case of cryptococcal meningitis unrelated to AIDS]. / Un raro caso di meningite criptococcica non correlata ad AIDS.

It is presented the clinical case of a man 60 years old, heterosexual, suffering from chronic bronchopathy from old date, inveterate smoker, with previous diskotomy, herniotomy, who presents a symptomatology characterized from recurrent fever, productive cough, dyspnea, asthenia and headache for 6 month. He was admitted to hospital for fever and for a sensory slightly obnubilated. A series of investigations for typhus fever, cytomegalovirus, all with negative results were performed. He resulted negative also to the test to PPD as well as to markers of B and C hepatitis and the test for HIV. The study of the principal cancer markers also gave negative results, while the blood smears displayed leukopenia with monocytosis. The magnetic nuclear resonance of the brain showed the presence of multiple lesions of the brain and along the meninges: the examination of the liquor underlines the presence of the Cryptococcus neoformans, making to set the diagnostic of cryptococcal meningitis. The immunological study showed low values of CD4 in presence of normal values of CD8 and of a normal natural killer function. The exitus happened at 64th day. The interest of the case consists in the fact that in the medical Italian literature, unlike the international one, are not described cases of cryptococcal meningitis in patients not infected by HIV.

Elevated levels of lipoprotein (a) in patients suffering from myocardial infarction with carotid atherosclerotic lesions.

The aim of the present study was to evaluate metabolic, coagulation and fibrinolytic parameters in 45 patients [31 men, 14 women, aged 56.5 +/- 3.5 years (mean +/- SD)] who had suffered myocardial infarction more than 6 months earlier, with or without carotid atherosclerotic lesions. After the extracranial carotid arteries had been evaluated using a B-mode Duplex scanning system, patients were subdivided into two groups: group 1 (n = 20) with carotid plaques or measurable intima-media thickness; and group 2 (n = 25) without carotid plaques or measurable intima-media thickness. Twenty-two age- and sex-matched subjects were recruited as controls (group 3). Groups 1 and 2 displayed significantly higher levels of total cholesterol, apolipoprotein B, human autoantibodies against oxidised low-density lipoprotein and the c fraction of the third component system, and significantly lower levels of high-density lipoprotein cholesterol and apolipoprotein A1 than group 3. However, serum levels of triglyceride and lipoprotein (a) were significantly higher in group 1 than in the control group. Moreover, groups 1 and 2 displayed significantly higher levels of factor VII, fibrinogen, fragment 1+2, thrombin-antithrombin complex and plasminogen activator inhibitor after venous occlusion, and significantly lower levels of tissue-type plasminogen activator after venous occlusion than group 3. Significantly higher levels of tissue-type plasminogen activator and plasminogen activator inhibitor before venous occlusion were observed in groups 1 and 2 and significantly lower levels of antithrombin III, protein C and protein S were observed in group 1 compared with the controls. Patients were also analysed according to levels of lipoprotein (a). The lowest levels of tissue-type plasminogen activator after venous occlusion and the highest levels fragment 1 + 2, the c fraction of the third component system, and plasminogen activator inhibitor after venous occlusion were observed in patients with the highest levels of lipoprotein (a). Our data demonstrate an activation of coagulation and deficient fibrinolysis in survivors of myocardial infarction, particularly in those with associated carotid atherosclerotic lesions. We speculate that this thrombophilic state may play a key role in the pathogenesis of atherosclerotic vascular disease and thromboembolic complications.

[The evaluation of the time of gastric radio-isotopic emptying in subjects with non-insulin dependent diabetes mellitus]. / Valutazione dei tempi di svuotamento gastrico radio-isotopico in soggetti con NIDDM in terapia con cisapride.

Abnormal gastro-intestinal motility is a well-recognized complication of autonomic neuropathy in diabetics; delayed gastric emptying is frequently documented. Various pharmacologic agents have been used to treat this complication such as cisapride. We have evaluated the effects of cisapride on gastric emptying in nine diabetic patients with autonomic neuropathy through radio-scintigraphic method. Gastric emptying diabetic patients was significantly prolonged compared control subjects (p < 0.01). In our study cisapride increased gastric emptying, but this did not reach statistical significance. We concluded that cisapride may be considered as a good alternative in cases where limited efficacy or side effects preclude the use of metoclopramide.

Anti-HBV neonatal immunization with recombinant vaccine. Part I. Critical appraisal for a long-lived antibody course.

This study involved 912 infants born to HBsAg-negative mothers from 1 May 1991 to 30 June 1992. The subjects were randomly allocated to an accelerated (Group A) or traditional (Group B) immunization schedule and immunized with 10 micrograms of recombinant HBV vaccine. At the end of the vaccinal cycle 98.14% of both groups were protected against HBV with a high percentage of high responders (88.1% group B and 68% group A). Following a random plan, 345 of the initial 912 infants (144 group A and 201 group B) were serologically evaluated, 15-18 months after the booster dose, to identify the level of long-lasting specific antibody. The data obtained allowed us to identify the non-responder subjects after the seroconversion, to propose the evaluation of antibody titre after the booster dose of vaccine and, because one year after the booster dose 5.6% of the subjects responsive at seroconversion have shown undetectable anti-HBsAg titre, to propose the elevation of the antibody level considered as protective at the end of the vaccinal cycle.

Correlations of crystal structures of DNA oligonucleotides with enantioselective recognition by Rh(phen)2phi3+: probes of DNA propeller twisting in solution.

Rh(phen)2phi3+ (phen = 1,10-phenanthroline; phi = 9,10-phenanthrenequinone diimine) avidly binds to DNA via intercalation from the major groove and upon photoactivation produces strand scission with single base 5' asymmetry. Enantiomers of Rh(phen)2phi3+, which lack hydrogen-bonding substituents in ancillary positions, distinguish a DNA site through shape-selection; site recognition depends upon the local variations in structure at a binding site. Here, we examine the application of delta-Rh(phen)2phi3+ as a sequence-dependent structural probe and, in particular, as a probe of DNA propeller twisting in solution, by comparing directly cleavage results using delta- and lambda-Rh(phen)2phi3+ on crystallographically characterized oligonucleotides with several sequence-dependent crystallographic parameters. The three oligonucleotides examined in this study are the Dickerson-Drew dodecamer, 5'-CGCGAATTCGCG-3', the NarI dodecamer, 5'-ACCGGCGCCACA-3', and the CG decamer, 5'-CCAACGTTGG-3', all of which have been crystallized in the B-form. Enantioselective cleavage and reaction favored by the delta-isomer is found to be governed locally by the opening of the site in the major groove. A correlation is demonstrated between cleavage by delta-Rh(phen)2phi3+ and the opening in the major groove that results from the change in propeller twist (differential propeller twist) at a base step. When the major groove is closed as a result of a change in propeller twist, there is little cleavage evident by either enantiomer; at sites which are indicated crystallographically to be open in the major groove, a direct correlation is observed between enantioselective cleavage and the degree of opening. A trend of higher enantioselectivity at sites possessing higher twist angles is also observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for soluble and nuclear site I binding of estrogens in human aorta.

The purpose of this study was to establish the estrogen receptor (ER) expression and content in human aorta fragments removed at the time of by-pass surgery. To this end, we adopted a radioligand binding assay to evaluate either soluble (S) or nuclear (N) ER using dextran-coated charcoal (DCC) and filtration methods, respectively. To better define the intratissular distribution and content of ER, we also measured the presence of a 27 kDa heat shock protein (HSP27), a well established ER-associated protein, using D5 monoclonal antibody. Finally, we analysed the different molecular isoforms of both S and N ER using size exclusion-high performance liquid chromatography (SE-HPLC). High affinity (type I) sites of estrogen binding were detected in 17 out of 19 samples in either S or N fraction, although only 9 out of 19 cases displayed site 1 ER in both cell compartments. ER levels in aortic tissues, detected by radioligand method, compare well with those we have found in other hormone-sensitive human cancer tissues and cells. SE-HPLC analysis revealed two main receptor isoforms in the soluble fraction, having 65 kDa and 18 kDa molecular mass, while a minor component of 29 kDa was also found; the nuclear fraction displayed again two major components of 38 and 23 kDa. Using the HSP27 immunohistochemistry we observed a major staining occurring in smooth muscle cells (SMC), with an increasing intensity towards the lumen. All samples, including the ER negative ones, exhibited some degree of histochemical staining. Using an arbitrary cut-off value, 7 out of 12 samples displayed a highly positive staining, 6 of which showed nuclear ER. Furthermore, SE-HPLC separation indicated the presence of a 64.9 kDa component in the soluble fraction, according to the well known relative molecular mass of ER. Following HSP27 immunohistochemistry, the overall staining intensity in aortic SMC approaches that seen in endometrial and breast epithelia, whilst the muscle ER content is generally lower. Although our data are compatible with a direct role of estrogens in arterial function, the extent of the link with arterial disease remains to be established.

Specificity and sensitivity of 3rd generation EIA for detection of HCV antibodies among intravenous drug-users.

Serum samples from 487 ambulatory I.V. drug users were screened for HIV and HCV antibodies to determine the prevalence of coinfection in this high risk group for AIDS. For anti-HCV antibody screening we first used a 3rd generation EIA using, as antigen synthetic peptides which were not subjected to false positive results due to antibodies against superoxide dismutase or against yeast proteins (which may copurify with the recombinant proteins employed in the first and second generation test). The specimens that were positive in the screening test were confirmed by a more specific EIA system that detect antibodies to proteins encoded by structural (HCV-st EIA) and non structural (HCV-nst-EIA) regions of the HCV genome. A second confirmation assay was also performed: sera were run in presence or absence of blocking reagents which inhibits antibodies to C200 and C22 HCV epitopes for binding to the solid phase. The sensitivity of the HCV EIA screening for human HCV antibody detection revealed a 100% positivity for HCV infection. The confirmatory strategy presented in this paper revealed an HCV EIA specificity of 98.6%. In this work we demonstrated a significantly higher prevalence (p < 0.001) of HCV exposure in HIV infected individuals compared to the general population. Our experimental data also confirmed that HBV infection in drug-users at high risk for HIV infection was significantly associated with HCV infection (p < 0.001). In contrast, the acquisition of HIV by sexual contact was not a statistically significant risk factor for HCV coinfection.

Duration of immune protection after hepatitis B vaccine in newborns from HBsAg-positive carrier mothers.

A group of 43 healthy neonates born from HBsAg-positive mothers were evaluated for the presence of protective HBsAb titre after administration of hepatitis B plasma-derived vaccine and hepatitis B hyperimmune-globulin. At 36 months of life we found that a significant number of children had a low HBsAb serum level. This suggests that a close serologic follow-up is necessary to evaluate the optimal timing for the administration of a booster dose of the vaccine.

Sensitivity and specificity of anti-HIV ELISA employing recombinant (p24, p66, gp120) and synthetic (gp41) viral antigenic peptides.

We have developed two immunoassay systems, one designated HIV (p24, p66, gp41) ELISA that uses as antigens the immunodominant epitopes mixed from each of three major groups of HIV-1 proteins: the core (p24), the pol (p66) and the env (gp41) gene. The other immunoassay system consists of four separate ELISAs for detection of single antibodies to HIV gag gene (p24), HIV pol gene (p66) and HIV env gene (gp41 and gp120). In the present study 200 specimens from patients with AIDS and 200 specimens from patients with ARC were repeatedly positive by HIV (p24, p66, gp41) ELISA. 1425 specimens from HIV drug addicts positive at W.B. were positive at HIV (p24, gp41, p66) ELISA. In addition, 60 samples that were indeterminate by W.B., were repeatedly positive at HIV (p24, p66, gp41) ELISA. The sensitivity and specificity of HIV (p24, p66, gp41) is estimated to be 100%. In this study 1507 specimens from HIV drug addicts, positive at W.B., were all positive (more than one test positive) at HIV p24 ELISA, HIV gp41 ELISA, HIV p66 ELISA and HIV gp120 ELISA used in combination. 135 samples from HIV positive drug addicts, positive at standard ELISA but indeterminate at W.B., were positive by HIV p24 ELISA, HIV gp41 ELISA, HIV p66 ELISA and HIV gp120 ELISA using the same criteria as in W.B. interpretation. The specificity (defined in terms of percentage of non-reacting persons in a low risk population) of HIV p24 ELISA, HIV gp41 ELISA, HIV p66 ELISA, HIV gp120 ELISA is 100%. In this work we demonstrated that: a) HIV (p24, p66, gp41) ELISA could be used as an adjunct or reliable alternative to standard ELISA for detection or confirmation of HIV antibodies in human sera; b) the specificity and sensitivity of antibodies to p24, p66, gp41, gp120 by ELISA used alone and/or in combination, is equal to or greater than W.B.

Endocytosis constitute the infectious route of HIV-1 entry in human and rabbit monocytes lacking the CD4 receptor.

To obtain "functionally" CD4 negative human monocytes (0-5 CD4 +/1 x 10(6)/cells), 50 ng/5.10(5) cells of OKT4A were added daily after a pre-incubation with OKT4A (100 ng/5.10(5) cells. In our experimental conditions the blocking the CD4 receptor of human monocytes with OKT4A monoclonal antibody did not prevent HIV-1 infection, although the level of virus replication appeared lower than that in cultures without OKT4A. "Naturally"CD4 negative rabbit monocytes infected with HIV-1 also released a detectable level of virus after 12-15 up 28-30 days. In "naturally" CD4 negative rabbit monocytes and "functionally" CD4 negative human monocytes, the virus particles entering via phagocytosis are not infectious because multiple well defined virions were observed in phagocytic vacuoles and the envelopes of these particles did not appear to interact with the vacuolar membrane. The infectious particles were represented by endocytic vesicles containing only the core of HIV after fusion between the viral envelope and endocytic membrane. Fusion between the viral envelope and plasma membrane on the cellular surface was never observed, in spite of examining greater than 1000 virions bound the surface of human and rabbit macrophage monocytes. The absence of cytopathic effect in the rabbit and human CD4 negative monocytes infected with HIV-1, and conversely the presence of specific sequences of HIV in the genomic DNA may indicate that the macrophages-monocytes serve as an important reservoir for the persistence of HIV in infected hosts, similar to the other related Lentiviruses. Our virological data have also demonstrated that virus infection can be transmitted from rabbit and human infected monocytes to uninfected H9 cells. This preliminary study may offer important evidence for the development and testing of vaccines and compounds that inhibit HIV penetration of susceptible cells.

The association of "standard ELISA" and HIV (env) ELISA for detection and confirmation of HIV antibodies in human sera.

Sera from various population of subjects, including patients with AIDS and ARC, drug-addicts seropositive for HIV and healthy blood donors were screened with "standard ELISA" and HIV (env) ELISA. In the present study all 80 specimens from patients with AIDS and all 60 patients with ARC were positive by HIV (env) ELISA, and 1507 specimens from HIV drug positive by W.B. were detected as positive by HIV (env) ELISA. The specificity of HIV (env) ELISA was defined in terms of percentage of non-reacting persons in a low risk population is 100%. Furthermore the HIV (env) ELISA is highly specific and sensitive and could be used in association with "standard ELISA" for detection and confirmation of HIV antibodies in human sera and plasma.