Necrotizing granulomatous vasculitis in advanced HIV infection

We describe the first case of granulomatous necrotizing vasculitis not restricted to the central nervous system in an HIV-infected patient. No mycobacteria or drugs potentially associated with granuloma formation were involved in this patient, suggesting that the cause of this vasculitis was probably autoimmune. The development of granulomatous vascular inflammation in this patient with less than 200 CD4 cells/microl might have been due to immune overactivation. After starting potent antiretroviral therapy a profound immune deactivation was observed and the vasculitis did not relapse.

Bone involvement and abcess formation by neutrophil-rich CD30+ anaplastic large-cell lymphoma mimicking skeletal infection in an AIDS patient

Neutrophil-rich CD30+ anaplastic large-cell lymphoma (ALCL) is a rare pathological entity without distinct clinical behavior. Twelve cases of neutrophil-rich CD30+ anaplastic large-cell lymphoma (ALCL) have been reported, three of them were HIV-infected patients. All these reports stressed the presence of neutrophil infiltration as a new morphologic feature of CD30+ ALCL. Only one case of cutaneous involvement presented with microabscess formation. We describe a case of neutrophil-rich CD30+ ALCL in an AIDS patient with a clinical picture determined by the massive neutrophil infiltration of the tumor without necrosis nor local infection, but with the formation of abscesses.

Influence of hepatitis C virus coinfection on failure of HIV-infected patients receiving highly active antiretroviral therapy to achieve normal serum beta2microglobulin levels

The influence of hepatitis C virus (HCV) coinfection on the kinetics of serum beta2microglobulin levels in HIV-infected patients undergoing highly active antiretroviral therapy was analyzed. After 96 weeks of therapy, beta2microglobulin levels declined significantly both in 24 HCV seronegative and 16 HCV-infected individuals. Throughout the follow-up period, HCV-infected patients showed higher beta2microglobulin values than non-HCV-infected patients. These results show that HCV infection precludes immune deactivation in HIV-infected patients undergoing highly active antiretroviral therapy.

Transient rebounds of low-level viraemia among HIV-infected patients under HAART are not associated with virological or immunological failure

OBJECTIVE

To analyse whether blips are associated with a higher risk of virological or immunological failure than persistent undetectable viraemia (UND) among HIV-infected patients receiving HAART.

DESIGN

Retrospective cohort study.

SUBJECTS

Patients with blips or UND were selected from a prospective cohort of 330 patients under HAART for over 48 weeks. Blips were defined as detectable viraemia up to a maximum of 1000 copies/ml preceded by two consecutive visits and followed by one visit showing undetectable viraemia. Patients were included according to the following criteria: i) Blip group: patients that showed transient relapses of viraemia; ii) UND group: patients who had achieved UND on HAART before 24 weeks of therapy and that sustained viral suppression for four consecutive visits.

MAIN OUTCOME MEASURES

Virological and immunological failure.

RESULTS

Thirty seven (11%) and 65 (20%) patients showed blips and persistent UND, respectively. Virological failure was observed in three (8.1%) patients in the blip group and 11 (16.9%) patients in the UND group (P=0.25). The time to virological failure was shorter in the UND group (P=0.12). The rates of virological failure and the time to virological failure were similar between both groups after excluding patients with compliance <95%. The time to immunological failure was also similar in both groups (P=0.5). In a Cox model, only the use of saquinavir hard gel-based regimens was independently associated with the time to virological and immunological failure.

CONCLUSION

Patients under HAART with transient low-level viraemia are not at an increased risk of developing virological or immunological failure.

[Prevalence of Bartonella spp. seropositivity in human immunodeficiency virus-infected and non infected intravenous drug abusers]

BACKGROUND

Serology is an useful tool in the diagnosis of Bartonella spp. infections in human immunodeficiency virus (HIV) seronegative patients. The value of this technique in HIV co-infected individuals is unknown. The aim of this study was to assess the prevalence of Bartonella spp. seropositivity among intravenous drugs abusers (IDA), both HIV-infected and non-infected.

PATIENTS AND METHOD

A retrospective seroepidemiological study was carried out among 241 IDA. One hundred and forty-seven of them were infected with HIV type 1. The titer of serum IgG antibodies against Bartonella spp. were determined.

RESULTS

Thirty-three (14%) individuals were seropositive for Bartonella spp. Nineteen (13%) seropositive cases were found among HIV carriers and 14 (15%) among HIV uninfected people. No relationship between Bartonella spp. seropositivity and the CD4+ cell counts was found when HIV infected patients were analyzed.

CONCLUSIONS

We have found a similar prevalence of Bartonella spp. seropositivity in HIV-infected and non HIV-infected IDA.

Mortality due to liver failure and impact on survival of hepatitis virus infections in HIV-infected patients receiving potent antiretroviral therapy

The aim of the present study was to examine the causes of death, the mortality attributable to liver failure, and the impact of hepatitis virus infections on the survival of a cohort of HIV-infected patients before and after the extensive use of highly active antiretroviral therapy (HAART). Liver disease associated with hepatitis C virus (HCV) seems to be accelerated in patients infected with the human immunodeficiency virus (HIV). On the other hand, the effect of HCV on HIV progression was controversial before the introduction of HAART. However, the last study to report changes in mortality due to liver failure was published in 1997, and the impact of HCV carriage on the survival of HIV-infected patients receiving HAART needs to be clarified. In this investigation, 492 patients who were prescribed antiretroviral drugs between April 1989 and September 2000 were included in the study cohort. The median duration of follow-up of the cohort was 1,392 days. HCV infection was present in 323 (68%). Mortality attributable to AIDS decreased from 4.5 to 1.8 per 100 persons per year. Mortality due to liver failure increased from 0.3 to 0.5 per 100 persons per year ( P<0.01). The survival of patients with and without HCV infection was similar ( P=0.8). Although liver failure is an increasing cause of death among HIV-infected patients receiving HAART, HCV infection has still no impact on the survival of HIV-infected patients.

The high sensitivity of a PCR-ELISA in the diagnosis of cutaneous and visceral leishmaniasis caused by Leishmania infantum

In general, the conventional techniques available for the diagnosis of leishmaniasis have relatively low sensitivity. This means that parasite-rich samples (which can usually only be collected by very invasive methods, such as bone-marrow aspiration) must be employed. This problem has not yet been solved even by use of the PCR-based techniques currently available. However, a new PCR-ELISA has been developed for the diagnosis of cutaneous (CL) and visceral leishmaniasis (VL) caused by Leishmania infantum. This assay appears to have sufficient sensitivity to be effective in the diagnosis of VL not only when bone-marrow aspirates are investigated but also when the samples are of peripheral blood. Overall, the ability of the PCR-ELISA to detect Leishmania, in 76 samples (22 of peripheral blood, 36 bone-marrow aspirates and 18 skin samples) from 72 patients living in a endemic region, was better than that of culture or the examination of Giemsa-stained smears. For example, L. infantum kDNA was detected by PCR-ELISA in 15 (83%) of the 18 skin samples from suspected cases of CL, whereas the combined use of several classical techniques only confirmed the presence of amastigotes in five (28%) of these samples. Similarly, only 21 individuals were diagnosed as having VL by conventional techniques whereas 30 were found Leishmania-positive in the PCR-ELISA. The new PCR-ELISA also appears to be a suitable technique for detecting leishmanial kDNA in samples of peripheral blood from cases of L. infantum-HIV co-infection. The assay is more sensitive than the combined use of several conventional techniques in the diagnosis of subclinical VL, probably because those with subclinical infection have relatively low parasitic loads that are generally undetectable using the other techniques.

Incidence of and risk factors for symptomatic visceral leishmaniasis among human immunodeficiency virus type 1-infected patients from Spain in the era of highly active antiretroviral therapy

The way in which the extensive use of highly active antiretroviral therapy (HAART) has influenced the incidence of visceral leishmaniasis (VL) among human immunodeficiency type 1 (HIV-1)-infected patients is not yet understood. The present study assessed whether the incidence of symptomatic VL in HIV-infected patients has decreased since the introduction of HAART. Likewise, the role of other potential risk factors for VL was also analyzed. Therefore, 479 HIV-1-infected patients receiving antiretroviral treatment, according to the available drugs at each moment, were prospectively followed from April 1989 to June 2000 in two university hospitals in southern Spain. A bone marrow aspiration was performed when patients showed symptoms suggestive of kala-azar. A diagnosis of VL was made when Leishmania amastigotes were seen in Giemsa-stained samples or promastigotes were cultured in specific media. The median follow-up time was 1,380 [8 to 4,536] days. Twenty-one patients were diagnosed with symptomatic VL. The density of incidence of VL has decreased 64.8% as of January 1997, when HAART began to be used extensively in our area. The use of HAART was the main independent factor associated with VL; this therapy was a protective factor (adjusted hazard ratio [HR], 0.05; 95% confidence interval [CI], 0.02 to 0.15). CDC clinical category C at entry in the cohort (HR, 4.08; 95% CI, 1.46 to 11.35) and CD4(+) cell counts below 300 cells/mm(3) during the follow-up (HR, 3.96; 95% CI, 1.56 to 10.01) were also independently associated with kala-azar. A VL diagnosis prior to follow-up and low compliance with antiretroviral therapy were not independently associated with symptomatic VL, although statistical significance was almost reached (P = 0.1 and P = 0.08, respectively). In summary, the use of HAART has led to a fall in the incidence of symptomatic VL in HIV-infected patients. The main risk factor associated with kala-azar emergence in patients infected with HIV is deep immunosuppression.

Structural normalization of the lymphoid tissue in asymptomatic HIV-infected patients after 48 weeks of potent antiretroviral therapy

BACKGROUND

The hallmark of HIV infection is the involution and destruction of lymphoid tissue. However, very little information exists on the effect of highly active antiretroviral therapy (HAART) on lymphoid tissue structure.

OBJECTIVE

To evaluate the effect of a HAART regimen after 48 weeks on the architecture and cell regeneration of tonsil lymphoid tissue in HIV-infected patients with CD4 T cell counts > or = 500/microl.

METHODS

From June 1997 to February 1998 all asymptomatic HIV-infected patients with CD4 T cell counts > or = 500/microl seen at our unit were offered quadruple antiretroviral therapy. Tonsil biopsies were obtained at baseline and at 48 weeks. Tonsil tissue sections were examined to evaluate structural and immunohistochemical changes by two blinded and independent pathologists. Cell numbers were counted for selected markers in T-dependent zones.

RESULTS

Eleven patients were evaluable, six were excluded because of insufficient or inadequate sampling in at least one of the biopsies. Cellular depletion, plasma cell accumulation and prominent vessels were observed in all cases; three excluded patients with evaluable baseline biopsies showed similar tissue lesions. Follow-up biopsies demonstrated some degree of improvement in all patients. Germinal centres appeared in seven cases that were not seen at baseline. CD4 cell counts increased and CD8 cell counts decreased significantly in lymphoid tissue. An increase in CD45RA+ cells was observed; however, the proportion of CD45+Ki67+ cells did not differ between baseline and 48 weeks.

CONCLUSION

This study shows an unexpected range of moderate to severe lymphoid tissue lesions in mildly immunosuppressed HIV-infected patients, which was partly restored after 48 weeks of HAART.

Minimal liver injury in chronic hepatitis C virus infection is associated with low levels of soluble TNF-alpha/Fas receptors and acquisition in childhood

BACKGROUND/AIMS

The rate of progression to cirrhosis of chronic hepatitis C might be related to an upregulation of TNF-alpha/Fas pathways.

METHODS

The serum levels of soluble TNF-alpha type II receptor (sTNFr-II) and soluble Fas antigen (sFas) were analyzed in patients with different histological outcomes of chronic parenterally acquired HCV infection of similar duration.

RESULTS

One hundred and forty-five HCV-infected patients had a known duration of infection. Twelve (8.3%) patients had minimal changes and were assigned to the case group. The control group was selected from the 24 (17%) patients with cirrhosis and the 54 (37%) with chronic active hepatitis (CAH). Two controls, one with CAH and one with cirrhosis, were paired with the cases following these criteria: duration of infection, transmission route and sex. The proportions of genotype 1b and HCV RNA serum levels were similar among the groups. The median serum levels of sTNFr-II and sFas were significantly lower in the case group than in the control groups. The cases were significantly younger when they became infected than the control groups. Indeed, most cases were infected within the first 10 years of life. sTNFr-II and age at infection were independently associated with the minimal injury case group. When sTNFr-II was excluded from the logistic regression model, sFas and age at infection were independently associated with the case group.

CONCLUSION

The rate of progression of parenterally acquired chronic hepatitis C to end-stage liver disease might be related to an upregulation of the TNF-alpha/Fas pathways and an age-dependent host response.

Diagnosis of infections with Leishmania infantum using PCR-ELISA

On the basis of partial amplification of a cloned fragment of kDNA of Leishmania infantum which is specific for this species, we developed a PCR-ELISA technique which avoids the problems associated with classical diagnostic techniques. This technique was tested on 33 L. infantum strains from 19 different zymodemes, which were recognized equally. It was also used on human and canine clinical samples. PCR-ELISA has a higher sensitivity than the other techniques used (IFAT, parasite cultures, optical microscopy of stained samples) and permits detection of a minimum of 0.1 promastigotes or 1 fg of genomic DNA. PCR-ELISA can be used to diagnose human cutaneous leishmaniasis using material obtained by scraping the lesion margin, and human visceral leishmaniasis in HIV(+) individuals and canine leishmaniasis with peripheral blood samples. The presence of L. infantum in dogs with low antibody titres with IFAT technique (20 and 40) was demonstrated indicating that seroprevalence data from epidemiological studies underestimate the true rates of infection.

Extracellular superoxide dismutase overexpression improves behavioral outcome from closed head injury in the mouse

Oxidative stress is known to play an important role in the response of brain to traumatic insults. We tested the hypothesis that increased extracellular superoxide dismutase (EC-SOD) expression can reduce injury in a mouse model of closed head injury. Neurologic, cognitive, and histologic outcomes were compared between transgenic mice exhibiting a fivefold increase in EC-SOD activity and wild-type littermate controls. Severe or moderate transcranial impact was induced in anesthetized and physiologically controlled animals. After severe impact, transgenic mice had better neurological outcome at 24 hr postinjury (p = 0.038). Brain water content was increased, but there was no difference between groups. Moderate impact resulted in predominantly mild neurologic deficits in both groups at both 24 hr and 14 days postinjury. Morris water maze performance, testing cognitive function at 14-17 days after trauma, was better in EC-SOD overexpressors (p = 0.018). No differences were observed between groups for histologic damage in hippocampal CA1 and CA3. We conclude that EC-SOD has a beneficial effect on behavioral outcome after both severe and moderate closed head injury in mice. Because EC-SOD is believed to be predominantly located in the extracellular space, these data implicate an adverse effect of extracellular superoxide anion on outcome from closed head injury.

Evidence of increased risk for leishmania infantum infection among HIV-seronegative intravenous drug users from southern Spain

To assess the prevalence of markers of Leishmania infection, 93 intravenous drug users and 77 nonusers of intravenous drugs underwent a Leishmania skin test and a serum Leishmania antibody search. All participants were human immunodeficiency virus seronegative. The Leishmania skin test was positive in 24 intravenous drug users and in 10 non-users of intravenous drugs (P=0.038). Leishmania seropositivity was detected in 3 of 11 active intravenous drug users and in 3 of 82 former drug injectors (P=0.02). Positivity in the Leishmania skin test was associated with intravenous drug use (adjusted odds ratio, 2.33; 95% confidence interval, 1.03-5.24). The prevalence of Leishmania infection markers among intravenous drug users is higher than that among controls. This suggests that this parasite spreads through the sharing of needles.

Usefulness of route of transmission, absolute CD8+ T-cell counts, and levels of serum tumor necrosis factor alpha as predictors of survival of HIV-1-infected patients with very low CD4 + T-cell counts

Potential cofactors of survival in HIV-1-infected patients with CD4+ T-cell counts of < or = 100 cells/microl were investigated. All 132 patients with CD4+ T-cell counts of < or = 100 cells/microl were selected from 416 patients included in an antiretroviral therapy cohort (1989-1999). Fifty of 54 deaths were due to AIDS. There were significant associations (P<0.05) between survival and CD8+ T-cell counts, clinical AIDS stage, risk group, and antiretroviral drug regimen after baseline, but only the use of protease inhibitors had an independent effect on survival (hazard ratio [HR], 0.096; 95% confidence interval [95%CI], 0.094-0.097). A substudy restricted to the cohort of 108 patients never exposed to PIs detected independent associations between survival and CD8+ T-cell counts (P=0.0016), experience with antiretroviral therapy before baseline (HR, 2.52; 95%CI, 1.31-4.82), sexual risk group for HIV infection (HR, 3.7; 95%CI, 1.92-7.12), and levels of serum tumor necrosis factor alpha (P=0.02). This study confirms that the use of PI-containing antiretroviral regimens strongly predicts survival of HIV-1-infected patients with very low CD4+ T-cell counts. When the study was restricted to patients never exposed to PIs, the parenteral route of disease transmission, high absolute CD8 + T-cell counts, and low serum levels of tumor necrosis factor alpha were independent predictors of survival in extremely advanced HIV-1 disease.

Influence of highly active antiretroviral therapy on the outcome of subclinical visceral leishmaniasis in human immunodeficiency virus-infected patients

Seventeen human immunodeficiency virus-infected patients who were harboring untreated subclinical visceral leishmaniasis (VL) were prospectively followed up. None of the 11 patients who received highly active antiretroviral therapy (HAART) presented with symptomatic VL during follow-up, whereas 2 out of 6 patients who received therapy other than HAART had an episode of overt kala-azar. These findings suggest that HAART does not induce the evolution of latent VL into symptomatic disease.

HIV-1 plasma viremia not increased in patients receiving highly active antiretroviral therapy after influenza vaccination

The effect of vaccinating patients with sustained undetectable HIV-1 viremia (VL) achieved with highly active antiretroviral therapy was prospectively investigated. During the 1998 influenza immunization period, 39 HIV-1-infected patients who showed a VL<20 copies/ml for at least 6 months before the study entry date were vaccinated for influenza. Twenty-two vaccinees were immunized at entry. Seventeen controls were followed for 4 weeks after entry, crossing over then to the vaccination group. The proportion of patients with undetectable VL was not significantly different between the vaccination and control groups 2 and 4 weeks after entry. Therefore, influenza immunization of patients with undetectable viremia achieved with highly active antiretroviral therapy does not seem to affect VL.

Low levels of HIV-1 plasma viral load in patients infected with HIV-1 subtype b and advanced immunosuppression

OBJECTIVES

Some HIV-1 infected patients show low levels of viraemia despite having advanced immunosuppression. Cases with falsely undetectable viraemia by conventional PCR have been reported when patients were infected with non-B subtypes. The aim of this study was to investigate whether this immunovirological discordance can be due to the presence of HIV-1 non-B subtypes, and whether a modified PCR procedure can yield different HIV viraemia values in these cases.

METHODS

Fifteen HIV-infected patients either naive for antiretroviral drugs or under treatment, with HIV plasma viraemia below 1000 copies/mm(3)and CD4+ cell counts lesser than 500 or 300 cells/mm(3), respectively, were included. Serotyping, genotyping and HIV plasmatic viraemia determinations were performed in all individuals.

RESULTS

In five out of six treatment-naive patients the virus was categorized as non-B subtype by serotyping, although only one case was confirmed by genotyping as HIV-2. Eight out of nine patients under antiretroviral therapy were subtype B carriers by serotyping and confirmed by genotyping. The remaining patient was determined as a subtype A carrier by both procedures. A modified PCR procedure (Amplicor HIV Monitor Test version 1.5) did not yield higher viral load levels than the former version.

CONCLUSIONS

The presence of HIV-1 subtypes non-B can explain a minority of cases of this immunovirological discordance, but in most of them the reason is still unknown. Likewise, a PCR procedure adapted for detecting HIV-1 non-B subtypes fails to find higher plasma viraemia in patients with such a discordance.

The effects of self-movement, observation, and imagination on mu rhythms and readiness potentials (RP's): toward a brain-computer interface (BCI)

Current movement-based brain-computer interfaces (BCI's) utilize spontaneous electroencephalogram (EEG) rhythms associated with movement, such as the mu rhythm, or responses time-locked to movements that are averaged across multiple trials, such as the readiness potential (RP), as control signals. In one study, we report that the mu rhythm is not only modulated by the expression of self-generated movement but also by the observation and imagination of movement. In another study, we show that simultaneous self-generated multiple limb movements exhibit properties distinct from those of single limb movements. Identification and classification of these signals with pattern recognition techniques provides the basis for the development of a practical BCI.

CD4+ and CD8+ T lymphocyte regeneration after anti-retroviral therapy in HIV-1-infected children and adult patients

Previous studies have shown a slow recovery of naive CD4+ T cell counts after anti-retroviral therapy in HIV-1-infected adults, which is in accordance with thymus atrophy after puberty. Here we investigate whether or not different patterns of naive CD4+ and CD8+ T cell repopulation are present in adult and child patients undergoing anti-retroviral treatment. Thus, 25 adults under highly active anti-retroviral therapy and 10 children under combined anti-retroviral therapy were retrospectively analysed for T cell subpopulations at baseline (T0) and around week 12 (T1) and week 24 (T2) of anti-retroviral treatment. Mean serum HIV-1 RNA levels dropped in both groups. Recovery of T cells in adults was characterized by a heterogeneous response between patients, with only 44% of them increasing their naive CD4+ and CD8+ T cell counts at T1, and changes in mean total CD4+ T cells were mainly shaped by memory cells. Otherwise, children were characterized by an early increase in naive T cells. Thus, at T1, all children analysed had a strong rise in CD4+ (from 389 +/- 116 to 569 +/- 121 cells/microl; P < 0.01), and nine out of 10 also in naive CD8+ T cells (from 244 +/- 58 to 473 +/- 85 cells/microl; P < 0.05). However, no significant correlation between age and naive repopulation was observed (P = 0. 22) in children. Thus, children had the earlier and greater increases in naive T cell subsets than adults, probably due to a more active thymus, with the potential for immune reconstitution when HIV-1 replication is controlled.

High frequency of serious side effects from meglumine antimoniate given without an upper limit dose for the treatment of visceral leishmaniasis in human immunodeficiency virus type-1-infected patients

Organic pentavalent antimonials are one of the mainstays of treatment for visceral leishmaniasis (VL). Few data are available on the toxicity and efficacy of these drugs at the dosing schedule recommended by the Centers for Disease Control and Prevention (CDC) (Atlanta, GA). We analyzed 25 VL episodes in human immunodeficiency virus (HIV)-infected patients who were treated with meglumine antimoniate (MA) at the CDC-recommended dose in southern Spain. Adverse effects were observed in 14 (56%) VL episodes. In 7 (28%), treatment with MA was permanently discontinued due to serious adverse effects that included acute pancreatitis, acute renal failure, and leukopenia. Three (12%) patients died during therapy due to severe acute pancreatitis attributable to MA. The dosing regimen of MA currently recommended for treating VL is associated with a high rate of serious side effects in HIV-1-infected patients.

Reduction of immune system activation in HIV-1-infected patients undergoing highly active antiretroviral therapy

The aim of this work was to analyze the effects of highly active antiretroviral therapy on the chronically activated immune system of 26 antiretroviral-naive HIV-1-infected patients. Samples from baseline to week 24 or 36 of treatment were tested for serum levels of beta2-microglobulin, tumor necrosis factor alpha and soluble tumor necrosis factor alpha receptor type II, as well as for human leukocyte antigen-DR expression on T cells. After starting therapy, the mean HIV-1 RNA serum levels decreased and the mean CD4 + cell counts increased from baseline to week 36 (P< 0.001). Mean levels of tumor necrosis factor alpha receptor type II, tumor necrosis factor alpha and beta2-microglobulin as well as expression of human leukocyte antigen-DR were significantly reduced at the end of follow-up (P<0.01). Deactivation kinetics of these parameters was similar in patients with CD4+ counts>200 cells/microl at baseline versus those with CD4 + counts < 200 cells/microl at baseline, despite higher activation at baseline in the group with <200 cells/microl. In summary, this study shows that highly active antiretroviral therapy is able to induce a strong deactivation of the immune system of HIV-1-infected patients.

Effects of cigarette smoking and 12-h abstention on working memory during a serial-probe recognition task

Nicotine has been shown to affect attentional and mnemonic processes. However, whether these effects are due to changes in perceptual and/or motor aspects of the tasks is not at all clear. This study tested the hypothesis that nicotine from cigarette smoking has differential effects on perceptual and motor processes, as reflected by event-related potentials (ERPs) and reaction times (RTs), respectively, and that perceptual effects may be specific to changes in working memory. ERPs. RTs and performance accuracy were recorded from smokers and nonsmokers during a serial-probe recognition memory task in which lists of words or "memory sets" were followed by a probe word that was either in-set or out-of-set. Smokers were tested in a "smoking" and a 12-h "deprived" condition. Smoking-smokers and deprived-smokers exhibited fast RTs to in-set and out-of-set probes relative to a group of nonsmokers. They exhibited even faster RTs when the inset probe word matched the first or last item in the memory set. Thus, smokers as a group showed enhanced primacy and recency effects suggesting that smoking specifically facilitates processes related to the motor output aspects of working memory. Different effects characterized the electrophysiology. Larger P300s were recorded to in-set compared to out-of-set probes by both subject groups. Smoking smokers exhibited enhanced P300s to both types of probes. When smokers abstained for 12 h (deprived smokers), the differences in P300 amplitude were reduced but not eliminated. Smoking smokers exhibited faster P300 latencies to in-set probes, while deprived smokers showed delayed latencies relative to nonsmokers. Primacy and recency P300 effects characterized nonsmokers and deprived smokers. However, this relationship was reversed in the Smoking condition. These results support the hypotheses that nicotine has distinct effects on memory-related perceptual and motor aspects of working memory. The increase in efficiency of the memory search with nicotine is consistent with the functional role of the cholinergic system in maintaining a state "appropriate for efficient information processing."

Prevalence of and factors associated with visceral leishmaniasis in human immunodeficiency virus type 1-infected patients in southern Spain

The actual prevalence of visceral leishmaniasis among human immunodeficiency type 1 (HIV-1)-infected patients in the Mediterranean basin remains unknown. There is also controversy about the risk factors for Leishmania infantum and HIV-1 coinfection. To appraise the prevalence of visceral leishmaniasis in patients infected with HIV-1 in southern Spain and to identify factors associated with this disease, 291 HIV-1 carriers underwent a bone marrow aspiration, regardless of their symptoms. Giemsa-stained samples were searched for Leishmania amastigotes. Thirty-two (11%) patients showed visceral leishmaniasis. Thirteen (41%) patients had subclinical cases of infection. Centers for Disease Control and Prevention (CDC) clinical category C was the factor most strongly associated with this disease (adjusted odds ratio [OR], 1.88 [95% confidence interval, 1.22 to 2.88]), but patients with subclinical cases of infection were found in all CDC categories. Female sex was negatively associated with visceral leishmaniasis (adjusted OR, 0.42 [95% confidence interval, 0.18 to 0.97]). Intravenous drug users showed a higher prevalence than the remaining patients (13.3 versus 4.9%; P = 0.04), but such an association was not independent. These results show that visceral leishmaniasis is a very prevalent disease among HIV-1-infected patients in southern Spain, with a high proportion of cases being subclinical. Like other opportunistic infections, subclinical visceral leishmaniasis can be found at any stage of HIV-1 infection, but symptomatic cases of infection appear mainly when a deep immunosuppression is present. There is also an association of this disease with male sex and intravenous drug use.

Prevalence of genotypic resistance to nucleoside analogues in antiretroviral-naive and antiretroviral-experienced HIV-infected patients in Spain

OBJECTIVE

To determine the prevalence of genotypic resistance to nucleoside analogues (NA) in a large group of HIV-infected individuals in Spain, some of whom had no previous treatment with antiretroviral drugs (antiretroviral-naive) and some of whom had such experience (antiretroviral-experienced).

SETTING

Cross-sectional study in out-patient clinics in three reference hospitals for HIV/AIDS located in Barcelona, Madrid and Seville, Spain.

PATIENTS AND METHODS

Primary mutant genotypes were examined in plasma HIV RNA collected from 150 antiretroviral-naive subjects, half in 1993 and the other half in 1997. Furthermore, drug resistance mutations were analysed in plasma collected from another 150 antiretroviral-experienced patients who had received 2 NA for longer than 1 year, either in sequence as monotherapy or as combination therapy. A line probe assay was used for recognizing mutations conferring resistance to zidovudine (ZDV), didanosine (ddI), zalcitabine (ddC), and lamivudine (3TC). A point-mutation nested-PCR assay was used for examining a codon 151 mutation associated with multiple drug resistance.

RESULTS

One or more mutations associated with primary resistance to NA were seen in 10 antiretroviral-naive (13.3%) patients in 1993 and in nine (12%) in 1997. In all but two cases, they were associated with ZDV resistance. In contrast, all but six (96%) of the antiretroviral-experienced subjects harboured drug-resistant mutant viruses. The codon 184 mutation (associated with resistance to 3TC) was detected in 92% of patients treated with 3TC, but also in 18% of those treated with only ddI or ddC. The codon 215 mutation was found in 67.3% of patients who had been exposed to ZDV; the codon 69 mutation was found in 15% of patients treated with ddC; and the codon 74 mutation was found in only 7.2% of patients treated with ddI. Finally, the codon 151 multidrug resistant mutation was found in four (2.7%) of 150 patients with a long-term exposure to NA.

CONCLUSIONS

Overall, the prevalence of drug-resistant HIV-1 genotypes was 12.7% in antiretroviral-naive patients, most of whom had ZDV-resistant mutants. There is no evidence of an increase during the last 5 years. However, multidrug-resistant HIV genotypes are currently circulating in Spain.

Short-term evolution of HIV-1 viraemia and CD4+ cell counts in patients who have a primary mutation to zidovudine

OBJECTIVE

To investigate the different responses to antiretroviral treatment including zidovudine, of patients harbouring HIV with primary resistance to zidovudine, serum viral load, and CD4+ cell counts, for 24 weeks in a group of antiretroviral-naive patients with the codon 215 mutation of the HIV pol gene and in a control group at the start of treatment.

DESIGN

A case-control retrospective study (1989-1996).

METHOD

Nineteen out of 210 patients previously studied harboured the codon 215 mutation, had a self-reported compliance with treatment, a minimum follow-up of 24 weeks, and were treated with zidovudine alone or in combination with other nucleoside analogues. These patients were matched with 19 patients with wild-type strains at entry by initial CD4+ cell counts, clinical status, and antiretroviral treatment.

RESULTS

During the first 12 weeks, CD4+ cell counts increased (76+/-26 and 64+/-26 x 10(6)/l in wild-type and mutant virus-infected groups, respectively), decreasing slightly until week 24, although no significant differences were found between the two groups studied. Serum viral load decreased in both groups (change in serum viral load of 0.80+/-0.11 log10 and 0.87+/-0.26 log10 copies/ml, wild-type and mutant virus-infected, respectively), although no significant differences were found between groups.

CONCLUSION

No significant differences were found between patients with the primary mutation to zidovudine and control patients harbouring wild-type virus in terms of short-term response measured by serum viral load and CD4+ cell counts.

Influence of hepatitis C virus infection on the mortality of antiretroviral-treated patients with HIV disease

The aims of this study were to analyze the mortality directly attributable to chronic viral hepatitis in HIV-1 infected patients and to investigate the influence of hepatitis virus infections on the survival of this population. A cohort of 328 HIV-1 infected, antiretroviral-treated patients, followed up from 1989 to 1996, was investigated in the study. The median follow-up period of the cohort was 120 weeks. The median baseline CD4 + cell count of the cohort was 303 cells/mm3. Hepatitis C virus, hepatitis B virus and hepatitis D virus infections were present in 214 (65%), 16 (4.9%) and 9 (2.7%) patients, respectively. Sixty-seven (20.4%) subjects died but there was no information on the vital status of 36 patients (11%). The causes of mortality were AIDS in 49 (73%), liver failure in 3 (4.5%) and other causes in 15 (22.4%). The cohort was divided into two groups for survival analysis, the groups consisting of persons infected by a hepatitis virus and persons without hepatitis virus infection. There was no difference in survival between the two groups (p = 0.31, log-rank). It is concluded that mortality among HIV-1/hepatitis virus coinfected patients with moderate to severe immunosuppression is mostly due to AIDS, and that the survival of these subjects is not influenced by the presence of hepatitis virus infections, particularly hepatitis C virus.

[Impact of medical approach on the presentation form of AIDS defined by clinical episodes]

BACKGROUND

In recent years there has been a change in the opportunistic diseases incidence in HIV-infected patients. The change could be related to the use antiviral therapy and chemoprophylaxis strategies. The aim of the present study was to evaluate if medical intervention is able to modificate the clinical presentation of AIDS and the CD4+ lymphocyte counts at time of AIDS diagnosis.

PATIENTS AND METHODS

The first AIDS-defining condition and the CD4+ count at time of AIDS diagnosis were analyzed in 95 HIV-infected patients who developed an AIDS-defining disease since April 1989 until March 1996, retrospectively reviewed. Patients who had been previously followed at an AIDS Unit were compared with those who had not.

RESULTS

The frequency of Pneumocystis carinii pneumonia as the first AIDS-defining condition was lower in medically followed patients. Among this group, AIDS cases who received chemoprophylaxis with isoniazide showed a decrease in the rate of tuberculosis. No differences were found in CD4+ lymphocyte counts between both groups.

CONCLUSIONS

As a result of medical intervention significant changes have occurred in the spectrum of initial AIDS-defining conditions in relation to medical intervention; a decrease in the frequency of Pneumocystis carinii pneumonia and tuberculosis have been found; however, the CD4+ lymphocyte counts at time of AIDS diagnosis are not modificated by medical intervention.

Low sensitivity of peripheral blood smear for diagnosis of subclinical visceral leishmaniasis in human immunodeficiency virus type 1-infected patients

The peripheral blood smear is an easy method for the diagnosis of symptomatic visceral leishmaniasis (VL) in human immunodeficiency virus type 1 (HIV-1)-infected patients. However, its efficiency in diagnosing subclinical VL remains unknown. In this study, Leishmania amastigotes were seen in blood smears from 1 of 13 HIV-1-positive individuals with subclinical VL. This shows that this procedure is not suitable for subclinical-VL diagnosis.

Human and monkey P3-like responses in a mixed modality paradigm: effects of context and context-dependent noradrenergic influences

Previous studies in non-human primates have reported that noradrenergic agents, such as the alpha 2 agonist clonidine, affect auditory but not visual P3 responses. One explanation for these effects may be that distinct modalities are differentially susceptible to noradrenergic influences--a modality-dependent effect. Another possibility is that noradrenergic effects are modality-independent but context-dependent. Two separate experiments, in humans and monkeys, examined the role of stimulus modality, context and noradrenergic activity in an attempt to elucidate the nature of the relationship between P3 and the action of this catecholamine neurotransmitter. In Experiment 1, human subjects were exposed to two versions of a mixed modality oddball paradigm. In one version, the context or background activity was auditory, while in the other it was visual. In both versions of the paradigm, the same auditory and visual rare targets occurred. The results indicated that N2 and P3 to visual targets were more sensitive to changes in context than those to auditory targets. In both cases, N2 and P3 amplitudes to targets were enhanced when the eliciting event and context differed. A modality-specific N2b, on the other hand, was enhanced when the context matched the modality of the eliciting event. In Experiment 2, monkeys received systemic injections of a saline placebo or one of three doses of the adrenergic antagonist L657,743 prior to presentation of a mixed modality oddball paradigm in a visual context. Drug effects were observed on earlier components such as N1, P2 and N2 but not on later P3-like responses. The combined findings complement previous ones from our laboratory and suggest that P3 reflects context-dependent processes and specifically context-dependent, not modality-specific, noradrenergic activity.

Unexpected high prevalence of hepatitis C virus genotype 4 in Southern Spain

BACKGROUND/AIMS

A unusually high rate of HCV-infected individuals in whom the HCV genotype cannot be ascertained by means of single PCR and LIPA procedures has recently been reported in our area. The aim of the present study was to investigate the epidemiological, clinical and molecular characteristics of these patients.

METHODS

Cross-sectional study. Eighty anti-HCV-positive patients with chronic liver disease, 45 (56.25%) of them intravenous drug users, were included. HCV genotyping was carried out in all patients using commercial single PCR and LIPA procedures. Samples where no HCV RNA amplification and/or indeterminate HCV genotype were found were also tested by means of a nested PCR. HCV viral load was measured in all patients.

RESULTS

HCV genotyping was not achieved in 23 (28.75%) individuals. No amplification of HCV RNA was found in 19 of them, and in four other cases the LIPA procedure did not allow identification of a distinct HCV genotype. After the use of nested PCR+LIPA, it was found that the HCV genotype 4 was found in 11 of those 23 individuals (47.82%). Ten of these 11 HCV genotype 4-harboring individuals were intravenous drug users. The HCV viral load was lower in HCV genotype 4-harboring individuals than in those whom the genotypes 1, 2 or 3 were found (p<0.001).

CONCLUSIONS

A high rate of HCV genotype 4-harboring cases has been found among HCV-infected individuals in Southern Spain. Had only single PCR been used, these individuals could have been wrongly regarded as non-viremic.

Viraemia and p24 antigenaemia are independent risk factors for the emergency of a zidovudine-resistant genotype in nucleoside analogue-treated HIV-1 infection

We aimed to determine, in an observational retrospective study, whether baseline HTV-1 RNA is an independent predictive factor for the emergence of a genotype associated with zidovudine resistance and whether previously identified predictive factors remain independent when viraemia is taken into account. Fifty nucleoside-naive HIV-1-infected individuals initiating zidovudine therapy (in 11 cases associated with didanosine) were submitted to clinical, immunological and virological monitoring at entry and every 12 weeks thereafter. The critical endpoint of the study was the influence of key baseline characteristics (CD4 cell counts, clinical stage, HIV-1 p24 antigen, virus phenotype and viraemia) upon the time to development of mutation at codon 215. The presence of serum p24 antigen, syncytium-inducing (S1) phenotype, a HIV-1 RNA load greater than the median (32495 RNA copies/ml), CD4 cell counts lower than 200/mm3 and clinical CDC category C were all baseline features associated with more rapid development of the mutant RT215 genotype in the univariate analysis. However, a multivariate Cox proportional hazard stepwise regression analysis showed that only baseline p24 antigenaemia, SI phenotype and a HIV-1 RNA load greater than 32495 RNA copies/ml were sequentially selected as independent predictive factors for the development of the mutant genotype. The present study suggests that baseline HIV-1 RNA load is an independent predictive factor for the development of a zidovudine resistance genotype. Likewise, it reinforces the independent predictive value of serum p24 antigenaemia and SI phenotype, even when viraemia is taken into account.

[A cystic lymphoepithelial lesion of the parotid in HIV-1-infected patients]

Cystic lymphoepithelial lesion is an infrequent disorder involving the saliva glands mainly the parotid gland; however, its frequency has increased coinciding with the epidemics of HIV-1 infection. Three cases of parotid lymphoepithelial lesion in patients with HIV-1 infection, 2 of whom were hemophiliacs and one an ex-intravenous drug addict, are presented. In all the cases the lesion was a painless slow growth right submandibular mass, with no history of inflammation. Two of the patients had a contralateral tumor of the same characteristics which was not studied. Fine needle aspiration puncture was performed in the three patients although diagnosis was obtained by pathologic study following superficial parotidectomy. Cystic lymphoepithelial lesion is an entity to be taken into account on differential diagnosis of cervical masses in patients with HIV infection. In individuals with severe immunosuppression treatment should be conservative.

Association between hepatitis C virus seroreactivity and HIV infection in non-intravenous drug abusing prostitutes

Two hundred and ninety-four non-transfused prostitutes from Spain, who denied intravenous drug abuse, were tested for hepatitis C virus (HCV) antibodies. Seventeen (5.78%) of them were seropositive. Both in univariate and correspondence analyses, serological results for hepatitis C were associated with the HIV-1 serostatus (p < 0.001), number of sex partners (p < 0.05) and a history of genital ulcers (p < 0.05). In logistic regression analysis, hepatitis C seropositivity was associated only with HIV-1 infection (adjusted odds ratio = 13.6; 95% confidence interval = 3.3-55.2). These results show that hepatitis C seropositivity is associated with HIV-1 infection in female non-intravenous drug abusing prostitutes. These findings are also consistent with the hypothesis that HCV can be sexually transmitted with low efficiency.

High rate of nonspecific anti-hepatitis C reactivity amongst homosexual men in comparison with that found in other sexually active groups and blood donors. Viral Hepatitis and AIDS Study Group

OBJECTIVES

To investigate the concordance of anti-hepatitis C virus (anti-HCV) reactivity by a second-generation enzyme immunoassay (EIA-2) and by a four-antigen recombinant immunoblot assay (4-RIBA) in homosexual men, in comparison with that found in other sexually active groups and blood donors.

DESIGN

Prospective study.

SETTING

Tertiary referral centre, Seville, Spain.

SUBJECTS

A total of 1203 subjects were studied. Eight hundred and three were sexually active individuals: 547 female prostitutes, 88 heterosexual men who had frequent sexual intercourse with prostitutes, and 168 homosexual men. All of them denied blood transfusion and parenteral drug use. In addition, 400 voluntary blood donors were selected at random.

MAIN OUTCOME MEASURES

All serum samples were screened for anti-HCV by EIA-2 and repeatedly reactive sera were tested by 4-RIBA. Homosexual men were also screened for anti-human immunodeficiency virus (anti-HIV), hepatitis B virus (HBV) markers and gammaglobulin concentration. Finally, serum samples from homosexual men reactive for anti-HCV by EIA-2 were analyzed for HCV-RNA by polymerase chain reaction (PCR).

RESULTS

Concordance between EIA-2 and 4-RIBA in female prostitutes (71.4%), clients of prostitutes (75.0%), and blood donors (83.3%) was significantly higher than in homosexual men (38.8%) (P < 0.04). In this collective the concordance between 4-RIBA and PCR was 85.7% for positive cases and 88.8% for negative ones, and EIA-2 ratios in reactive sera were significantly higher in 4-RIBA confirmed cases (P < 0.0001). No correlation between false positive EIA-2 results and presence of HIV infection, HBV markers or hypergammaglobulinaemia was found in homosexual men by univariate analysis.

CONCLUSIONS

There is a high level of non-specific anti-HCV reactivity by EIA-2 amongst homosexual men in comparison with that found in other sexually active groups and blood donors. The true prevalence of HCV infection amongst homosexual men could be even lower than previously described.

Face recognition as a function of social attention in non-human primates: an ERP study

Epidural event related potentials (ERPs) were recorded from four squirrel monkeys (Saimiri sciureus) during the presentation of pictoral stimuli that comprised real human and monkey faces. Subjects viewed tachistoscopically presented stimuli belonging to four different categories: familiar and unfamiliar human faces, and familiar and unfamiliar monkey faces. Familiar faces were subcategorized into top, middle and bottom according to the perceived individual's dominance ranking in a social hierarchy, as rated by human judges observing the group's social behavior. Waveform peak components to monkey and human faces showed similarities in their spatial distribution. However, larger amplitude N1 and N2 components were elicited in response to monkey compared to human faces, particularly over lateral temporo-parietal sites. A similar trend was observed for the P3 component, with maximal differences along midline electrode site. Responses to familiar and unfamiliar monkey faces showed larger N1s to familiar monkey faces and larger P3s to unfamiliar monkey faces. N1 and P3 components elicited by human faces showed no significant differences between conditions. N2 amplitudes were larger over posterior sites for top-ranked monkeys and larger over frontal sites for middle- and bottom-ranked monkeys. Top-ranked human faces elicited the largest N2 components, middle-ranked faces the next largest, and bottom-ranked faces the smallest. N1, N2, and P3 latencies were similarly sensitive to the ranking of human but not monkey faces. These data suggest that non-human primates exhibit evoked potentials to conspecific and non-conspecific faces that are similar in morphology but different in function. Larger amplitude responses to monkey faces suggests increased processing for that category of stimuli. Additionally, monkey ERPs reflect familiarity with conspecifics but not with human faces. Finally, the social status of the perceived individual, or at least the perceived threat posed by an individual, affects the latencies and magnitudes of ERP components produced by the viewer. These data are consistent with social attention hypotheses which propose that higher status (i.e. more dominant or socially meaningful) members of a group receive more attention than lower status individuals.