Genotypic resistance profile and clinical progression of treatment-experienced HIV type 1-infected patients with virological failure

We explored the relationship between HIV-1 drug resistance in treatment-experienced patients and disease progression in a cohort of patients undergoing resistance testing to guide treatment decisions. A total of 601 treatment-failing individuals tested for genotypic HIV-1 drug resistance between 1998 and 2004 were selected. At genotypic testing, median HIV-1 RNA levels and CD4 counts were 3.8 log copies/ml and 293 cells/mul, respectively; 84% had resistance mutations to nucleoside reverse transcriptase inhibitors (NRTIs), 42% had resistance mutations to non-NRTIs, 51% had major resistance mutations to protease inhibitors (PI), 12% had no major resistance mutations to any drug class, 22% had mutations to one class, 42% had mutations to two classes, and 23% had mutations to three classes. During a follow-up of 714.7 patients/year, 80 patients showed an AIDS-defining event or died. In multivariable models adjusting for prior AIDS, baseline CD4 counts, HIV-1 RNA, and calendar year, viral resistance variables associated with increased hazards of clinical progression were the presence of reverse transcriptase substitution T215F (p = 0.002) and the presence of three or more protease substitutions among L33F/I/V, V82A/F/L/T, I84V, and L90M (p = 0.003). Resistance to three drug classes remained independently predictive of clinical progression only when calendar year was not used as an adjustment factor. Prevention and treatment of multiple drug class resistance are clinical priorities for HIV-infected patients. In recent years, improved treatment options may have helped in reducing part of the resistance-associated clinical progression.

Evolution of HVR-1 Quasispecies after 1-Year Treatment in HIV/HCV-Coinfected Patients According to the Pattern of Response to Highly Active Antiretroviral Therapy

Hepatitis C virus (HCV) variability is mainly attributed to the ability of the virus to respond to host immune pressure, acting as a driving force for the evolution of quasispecies. This study was aimed at studying the changes in HVR-1 heterogeneity and the evolution of HCV quasispecies in HIV/HCV-coinfected patients according to the pattern of response to highly active antiretroviral therapy (HAART).

Sixteen HIV/HCV-coinfected patients harbouring HCV genotype 1 and who had been on HAART for at least 1 year, 8 showing increasing CD4+T-cell counts (immunological responders) and 8 showing a stable or decreasing CD4+ T-cell counts (immunological non-responders), were selected from a prospective cohort study.

After 1 year of HAART, 11 patients showed HIV viral load <2.6 log10 cp/ml (virological responders), and 5 showed HIV viral load above this value (virological non-responders). Plasma samples, collected before starting therapy and after 1 year of HAART, underwent clonal sequence analysis for HVR-1 region of HCV. Non-synonymous/synonymous substitutions ratio (Ka/Ks), aminoacidic complexity (normalized Shannon entropy) and diversity (p-distance), were considered as parameters of quasispecies heterogeneity. After 1 year of HAART, heterogeneity of HVR-1 quasispecies significantly decreased in virological non-responders, whereas the heterogeneity tended to increase in virological responders. The differences in the evolution were less stringent, when considering immunological response. On the other hand, profound qualitative modifications of HVR-1 quasispecies were observed only in patients with both immunological and virological HAART response.

On the whole, these findings suggest that, in patients undergoing HAART, the extent of HCV variability and the evolution of HVR-1 quasispecies is influenced by the pattern of response to antiretroviral therapy.

Correlates of independent HIV-1 replication in the CNS and of its control by antiretrovirals

OBJECTIVE

To investigate in detail factors associated with independent replication of HIV-1 in CNS, and to predict its therapeutic control.

METHODS

HIV RNA concentration was measured by PCR in 134 cross-sectional paired plasma and CSF samples from 95 patients infected with HIV-1 with various conditions, and in longitudinal CSF samples from 50 patients on antiretroviral treatment. Monocyte chemotactic protein (MCP)-1 was quantified in CSF by ELISA.

RESULTS

High HIV RNA levels either in plasma or in CSF did not correlate with HIV RNA concentration in the paired biologic sample. A high CSF-to-plasma HIV RNA ratio, suggesting independent viral replication in the CNS, was associated with higher CSF viral load and higher CSF MCP-1 levels. Higher MCP-1 levels in the CSF were also associated with neurologic disorders and were not influenced by the use of highly active antiretroviral therapy (HAART). A higher number of antiretroviral drugs with CSF penetration correlated with a more profound CSF HIV-1 load reduction, independently from the use of HAART alone. Virologic suppression in CSF was predicted by a higher number of CSF-penetrating antiretrovirals and by the baseline CSF viral load, whereas lower baseline CD4 counts and higher MCP-1 levels were associated with increased risk of virologic failure.

CONCLUSIONS

Quantification of HIV RNA in CSF is clinically useful, particularly in patients with neurologic disorders. CSF penetration of antiretrovirals must be considered when choosing treatments, mainly in patients with higher CSF viral loads, advanced disease, and CNS disorders associated with significant macrophage activation.

Comparative bioavailability of diltiazem in prolonged-release oral preparations

This study was conducted to compare the bioavailability of two prolonged-release pharmaceutical forms containing 300 mg of diltiazem. The test formulation is a new design of tablets with a hydrophilic matrix, and the reference formulation is capsules containing prolonged liberation microgranules, in the same dose, that are commercially available in the pharmaceutical market. Diltiazem plasma concentrations were analyzed by high-performance liquid chromatography (HPLC), which involves solid-phase extraction for plasma sample preparation. Twelve healthy volunteers participated in the study, which had a single-dose, two-treatment, two-sequence-crossover, randomized design. The preparations were compared using pharmacokinetic parameters such as the area under the plasma concentration-time curve AUC(0-36), peak plasma concentration Cmax, and Cmax/AUC(0-36) ratio as a measure for the absorption rate. No statistically significant difference was observed for any of the parameters, and the 90% confidence intervals calculated for the ratio of the logarithmically transformed AUC(0-36) and Cmax/AUC(0-36) values of both formulations were within the bioequivalence limit of 0.80-1.25. Moreover, an in vitro study of dissolution according to USP 23 was conducted, and the in vitro parameters were calculated.

Stability of ranitidine tablets subjected to stress and environmental conditions, by HPLC

High Performance Liquid Chromatographic (HPLC) method was applied in this study to comparatively evaluate the stability of tablets in their original package which 150 mg of Ranitidine from six different pharmaceutical laboratories in the market, according to ICH conditions for accelerated testing: 40 degrees C, 75% RH with and without light for six months. The stability at environmental conditions was evaluated for a twelve-month period, with and without light, with the same purpose. Ranitidine is widely used to treat peptic ulcer diseases. Ranitidine is susceptible to degradation under the influence of light, humidity and temperature. The chromatographic conditions were: RP-18 column of 250 mm yen 4 mm ID and a particle size of 5 mm; mobile phase of Acetonitrile-Ammonium acetate solution (0.2 M) (70:30; v/v) (pH*6) adjusted with glacial acetic acid; flow rate of 1 ml min-1; 25 degrees C of temperature; detection at 322 nm; injection volume of 20 ml, using height peak as the integration parameter. The results obtained at six months indicate that the stability of Ranitidine depends on the correct formulation and the primary container. The remaining content of Ranitidine, dissolved percentage in vitro and total impurity percentage were determined by HPLC. Organoleptic characteristics were visually examined. The proposed analytical method was validated and linearity, precision and selectivity were determined. Degradation products were detected.

Better response to chemotherapy and prolonged survival in AIDS-related lymphomas responding to highly active antiretroviral therapy

OBJECTIVES

To evaluate the impact of response to highly active antiretroviral therapy (HAART) on the natural history of AIDS non-Hodgkin's lymphoma (NHL) and to analyse the feasibility, efficacy and toxicity of HAART in combination with chemotherapy.

DESIGN

Prospective observational study in two AIDS clinical centres in Italy.

METHODS

All consecutive HIV-infected patients with NHL were included (n = 44; 48% high-risk group) and prospectively followed for 27 months. HAART was administered concomitantly with chemotherapy. The association between response to HAART and clinical presentation, response to chemotherapy and toxicity was analysed by univariate and multivariate models. Survival analysis was performed by Kaplan-Meier estimates and the Cox proportional hazards regression model.

RESULTS

A complete response (CR) to chemotherapy was achieved in 71% of HAART responders and 30% of non-responders. Virological response to HAART was the only variable associated with tumour response on multivariate analysis. A higher relative dose intensity (RDI) of chemotherapy was administered in patients with virological response compared with those without. The probability of 1 year survival was higher in patients with virological or immunological response. At Cox regression analysis, immunological response, a higher RDI and a CR to chemotherapy were all associated with a reduced risk of death.

CONCLUSION

In HIV-infected patients with NHL, response to HAART was strongly associated with a better response to chemotherapy and prolonged survival. Concurrent treatments were well tolerated, and HAART-responder patients could receive a higher RDI of chemotherapy. In patients with AIDS lymphomas, combining HAART with chemotherapy could be a feasible and effective approach.

Female sex and the use of anti-allergic agents increase the risk of developing cutaneous rash associated with nevirapine therapy

To identify factors associated with cutaneous rash, we performed a retrospective multicentre analysis of HIV outpatients starting a highly active antiretroviral therapy regimen containing nevirapine. A total of 62 cutaneous adverse events were observed in 429 patients. Rash hazard was increased in women, by the prophylactic use of glucocorticoids or antihistaminics, and was reduced by escalating the initial dose of nevirapine. Women receiving glucocorticoids had a 3 month cumulative probability of rash of 0.41.

Epidemiology and prognosis of AIDS-associated progressive multifocal leukoencephalopathy in the HAART era

Whereas most AIDS-related neurologic disorders have reduced incidence since HAART therapy was introduced, we find that the incidence of progressive multifocal leukoencephalopathy (PML) did not significantly differ between the pre-HAART and the HAART period (OR 0.78; 95% CI 0.41-1.50). These findings were confirmed by the preliminary results of the Italian Register Investigative Neuro AIDS (IRINA) Study, a prospective multicenter study started in January 2000, which showed that PML was the second most frequently diagnosed neurologic disorder after TE. A similar proportion of cases were found in HAART-naïve and HAART-experienced patients in our experience. PML was more common in the presence of HIV RNA > 500 copies/ml. Most of the cases occurring in HAART-exposed patients developed within the first 6 months of therapy. As others have reported, we find a prolonged survival in PML subjects prescribed HAART (245 days in the group treated with HAART versus 66 days in the group not treated with HAART; P at log rank = 0.001). However despite the survival benefit, AIDS-associated PML still has a serious prognosis. In fact, PML had the lowest 1-year survival probability of any cerebral disorder in our study (P = 0.0005). Our findings also confirm that CSF JCV DNA burden at baseline is a useful prognostic indicator with a threshold of 4.7 log(10) JCV copies/ml (P at log rank = 0.01) in our experience. CSF JCV DNA load at 4 weeks of follow-up and clearance of JCV-DNA from CSF are associated with a better neurologic outcome and a longer survival.

Potent anti-retroviral therapy with or without cidofovir for AIDS-associated progressive multifocal leukoencephalopathy: extended follow-up of an observational study

To analyze the clinical efficacy of cidofovir combined with highly active anti-retroviral therapy (HAART) in AIDS-related progressive multifocal leukoencepalopathy (PML), a multicenter observational study was performed. Consecutive HIV-positive patients with histologically or virologically proven PML and at least 4 weeks of treatment after diagnosis were examined: 27 patients were treated with HAART, whereas 16 patients were treated with HAART plus cidofovir 5 mg/kg intravenously per week for the first 2 weeks and every other week thereafter. JC virus DNA was quantified in cerebrospinal fluid (CSF) by PCR. Baseline virologic, immunologic, and clinical characteristics as well as HIV RNA and CD4 responses to HAART were homogeneous between the groups. The median follow-up was 132 weeks. In one case (6%), cidofovir was permanently discontinued because of severe proteinuria. One-year cumulative probability of survival was 0.61 with cidofovir and 0.29 without (log rank test P = 0.02). After adjusting for baseline CD4 counts, JC viral load in CSF, Karnofsky, and use of HAART prior to the onset of PML, the use of cidofovir was independently associated with a reduced risk of death (hazard ratio, 0.21, 95% confidence interval, 0.07-0.65; P = 0.005). A randomized study will definitively establish whether cidofovir confers significant advantage over HAART alone in AIDS-related PML.

Self-reported nonadherence with antiretroviral drugs predicts persistent condition

PURPOSE

To assess variables predictive of nonadherence persisting over time in HIV-infected people treated with highly active antiretroviral therapy.

METHOD

Prospective study of consecutive HIV-infected patients who were prescribed ritonavir- or indinavir-containing regimens in a university-based HIV clinic in Rome. A patient questionnaire assessing knowledge of treatment regimen, adherence behavior, reasons for taking and missing therapy, factors influencing adherence, and health behaviors was administered at baseline and 1 year later. A predose protease inhibitor plasma level was measured concurrently. Persistent nonadherence was defined as patient self-reported nonadherence both at enrollment and at follow-up questionnaires.

RESULTS

From April 1998 to July 1998, 140 patients were enrolled into the study. At follow-up, 10% remained persistently nonadherent, and 15% of the previously adherent patients became nonadherent. On bivariate analysis, being less than 35 years old (odds ratio [OR] 8.9; 95% CI 1.8-43.1; p =.002), self-reporting nonadherence at enrollment (OR 14.5; 95% CI 3.5-5.8; p <.001), and having experienced "a fair amount" or "a lot" of vomiting (OR 11.1;95% CI 1.6-74.7; p =.02) or pruritus (OR 16.4; 95% CI 2.6-102.8; p =.004) during the 4 weeks before enrollment were significantly correlated to persistent nonadherence.

CONCLUSION

Previous self-reported nonadherence was a strong predictor of persistent nonadherence during follow-up. Moreover, being of younger age and self-reporting vomiting or pruritus were also associated with a higher risk of nonadherence persisting over time.

Plasma levels of interleukin-6 and interleukin-10 in preterm neonates evaluated for sepsis

In a prospective study, plasma interleukin-6 (IL-6) and interleukin-10 (IL-10) levels were measured by enzyme-linked immunosorbent assay in 45 premature neonates (25-34 weeks gestational age) with signs and symptoms of suspected sepsis at 0, 12 and 24 h; C-reactive protein (CRP) was measured at 0-24 h after enrolment. Six subjects were excluded due to insufficient blood sampling. The remaining 39 neonates were assigned to one of three groups: 25 newborns with sepsis (blood culture positive), seven with pneumonia (positive results on broncho-alveolar lavage fluid culture and characteristic chest radiography) and seven with necrotising enterocolitis (NEC) (characteristic intestinal and radiological signs according to the criteria of Bell et al.). A group of 20 healthy preterm neonates represented control subjects. On admission, higher levels of IL-6, IL-10 and CRP were observed in neonates with sepsis: IL-6 (median 1500 pg/ml, range 487-10000 pg/ml), IL-10 (median 113 pg/ml, range 70-196 pg/ml), CRP (median 22 mg/l, range 4-80 mg/l); pneumonia: IL-6 (median 1500 pg/ml, range 747-8000 pg/ml, IL-10 (median 84 pg/ml, range 76-92 pg/ml), CRP (median 10 mg/l, range 8-33 mg/l) and NEC: IL-6 (median 6650 pg/ml, range 1595-7950 pg/ml), IL-10 (median 80 pg/ml, range 61-147 pg/ml), CRP (median 3 mg/l, range 2.8-8 mg/l) as compared to controls (IL-6 median 208 pg/ml, range 198-349 pg/ml; IL-10 median 36 pg/ml, range 19-50 pg/ml; CRP median < 2 mg/l) (P < 0.05). In neonates with sepsis, IL-6 levels were significantly correlated with IL-10 levels (r = 0.65; P = 0.04) at the time of the second sample. The highest IL-6 levels were observed at onset, while IL-10 was predominant 12 h later. On admission, IL-10 and CRP levels were significantly higher in non-survivors (IL-10 median 507 pg/ml, range 422-753 pg/ml; CRP median 123 mg/l, range 20-219 mg/l) than in survivors (IL-10 median 76 pg/ml, range 61-143 pg/ml; CRP median 8 mg/l range 3-46 mg/l), while IL-10 levels were significantly higher (P < 0.05) also 12 h after admission (non-survivors: IL-10 median 600 pg/ml, range 538-800 pg/ml; survivors: IL-10 median 74 pg/ml, range 53-161 pg/ml). IL-6 and IL-10 levels were significantly correlated with CRP levels on admission (r = 0.45; P = 0.05).

CONCLUSION

Preterm neonates with sepsis, pneumonia or necrotising enterocolitis showed increased interleukin-6, interleukin-10 and C-reactive protein levels. High interleukin-10 concentration was associated with mortality and could be an early indicator of prognosis.

Incidence and determinants of bacterial infections in HIV-positive patients receiving anti-Pneumocystis carinii/Toxoplasma gondii primary prophylaxis within a randomized clinical trial

We assessed the incidence and determinants of bacteremia, pneumonia, and sinusitis/otitis in HIV-positive people receiving cotrimoxazole (CTX) or dapsone-pyrimethamine (DP) for primary prophylaxis of Pneumocystis carinii pneumonia (PCP) and toxoplasmic encephalitis (TE) within a randomized clinical trial. In total, 244 patients were randomized: 122 were assigned to CTX and 122 to DP. In the cohort, 22 bacteremia, 63 pneumonia, and 39 sinusitis/otitis cases were observed. Incidence rates of bacteremia, pneumonia, and sinusitis/otitis as well as the 2-year probability of remaining free from any bacterial infection were not significantly different between the two groups. At multivariate analysis, the risks of developing bacteremia and pneumonia were found to be independently increased by the use of a central venous catheter (hazard ratio [HR], 4.48; p <.05 and HR, 4.13; p <.01, respectively) and by hospitalization (HR, 28.82; p <.05 and HR, 10.15; p <.05, respectively). In conclusion, CTX at the dosage employed for primary PCP/TE prophylaxis does not seem to protect against bacterial infections more than second-line DP.

Changing clinical presentation and survival in HIV-associated tuberculosis after highly active antiretroviral therapy

OBJECTIVE

To assess changes in clinical presentation and outcome of HIV-associated tuberculosis (TB) before and after widespread implementation of highly active antiretroviral therapy (HAART).

METHODS

We reviewed clinical charts of HIV-infected patients with culture-confirmed pulmonary TB in two referral clinical centers in Rome, Italy. The 67 patients diagnosed in 1995 to 1996 were compared with 51 patients diagnosed in 1997 to 1998. To analyze factors associated with survival we used a Cox model including antiretroviral therapy as a time-dependent covariate.

RESULTS

Patients diagnosed in 1997 to 1998 were more likely to have TB as the first AIDS-defining illness (78% versus 58%, p <.05), to have HIV diagnosed <2 months before TB (33% vs. 7%, p <.005) and to have typical chest radiograph pattern (45% vs. 25%, p <.05), and had a higher CD4(+) count (median 105 vs. 43, p <.005). Survival at 1 year was 80% for patients diagnosed in 1997 to 1998 vs. 65% for those diagnosed in 1995 to 1996 (p by log-rank =.02). After adjusting at multivariate analysis, time period of diagnosis was not confirmed as associated with survival (hazard ratio, 1.05; 95% confidence interval, 0.39--2.81). Age, CD4+ cell count <25/mm(3), and AIDS-defining illnesses before TB diagnosis were all associated with an higher risk of death, whereas a decreased risk of death was observed in patients starting a triple combination antiretroviral therapy after TB diagnosis (hazard ratio, 0.14; 95% confidence interval, 0.03--0.57).

CONCLUSIONS

Cases of HIV-associated TB occurring in patients with advanced immunosuppression and presenting with atypical radiologic appearance tend to be relatively less common in the HAART era. HAART is a major factor in prolonging survival in these patients.

Expression of the c-met proto-oncogene and its ligand, hepatocyte growth factor, in Hodgkin disease

The receptor for hepatocyte growth factor (HGF) is a transmembrane tyrosine kinase that is encoded by the proto-oncogene c-met. Recently, c-MET was detected in Reed-Sternberg (RS) cells from Epstein-Barr virus-positive (EBV(+)) Hodgkin disease (HD). The c-MET, EBER-1, and LMP-1 expression in 45 lymph node biopsies and 12 bone marrow biopsies obtained from patients with HD was analyzed. In addition, HGF levels in serum samples from 80 healthy individuals and 135 HD patients in different phases of disease. In all 45 lymph node and 12 bone marrow samples examined, RS cells expressed c-MET but not HGF(+). These results were independent of the EBV infection. Interestingly, several HGF(+) dendritic-reticulum cells were found scattered around c-MET(+) RS cells. The mean +/- SEM serum HGF levels in HD patients at diagnosis and at the time of relapse were 1403 +/- 91 (95% confidence interval [CI], 1221-1585) and 1497 +/- 242 pg/mL (95% CI, 977-2017), respectively. HGF values were significantly higher than those of healthy individuals (665 +/- 28 pg/mL; 95% CI, 600-721; and P <.001 for both groups of patients) and of HD patients in remission (616 +/- 49 pg/mL; 95% CI, 517-714; and P <.001 for both groups of patients). A significant correlation was found between serum HGF levels and B symptoms at diagnosis (P =.014). In conclusion, this study indicates that HGF and c-MET constitute an additional signaling pathway between RS cells and the reactive cellular background, thereby affecting adhesion, proliferation, and survival of RS cells. Furthermore, the serum concentration of HGF in HD patients may be a useful tool in monitoring the status of disease.

A randomized trial comparing the introduction of ritonavir or indinavir in 1251 nucleoside-experienced patients with advanced HIV infection

ISS-IP1, a multicenter, randomized, 48-week open trial, was designed to compare the introduction of ritonavir or indinavir in patients with previous nucleoside experience and CD4+ cell counts below 50/mm3. Concomitant antiretroviral treatment with nucleoside analogs was allowed. Primary efficacy measures were survival and time to a new AIDS-defining event or death, analyzed through the whole period of observation by the intention-to-treat approach. Primary toxicity measures were time to treatment discontinuation and adverse events, grade at least 3/serious, analyzed by an on-treatment approach. Evaluation-of efficacy also included CD4+ cell and RNA response. The trial enrolled 1251 patients in 5 months. At baseline, mean CD4+ cell count was about 20 cells/mm3 and mean HIV RNA copy number was 4.9 log10/ml in both groups. Overall, 402 patients in the ritonavir group and 250 patients in the indinavir group permanently discontinued the assigned treatment (relative risk, 1.96; 95% CI, 1.68-2.30; p = 0.0001), with most of this difference dependent on a higher number of discontinuation for adverse events in the ritonavir group. After a mean follow-up of 307 days (ritonavir, 304; indinavir, 309), 124 deaths (ritonavir, 61; indinavir, 63; relative risk, 0.96; 95% CI, 0.67-1.36; p = 0.80) and 330 new AIDS-defining events (ritonavir, 170; indinavir, 160; relative risk, 1.05; 95% CI, 0.85-1.31; p = 0.60) were observed. CD4+ cell counts increased in both groups in patients still receiving treatment, with about 100 cells gained by week 24 and 150 cells gained by week 48. Body weight also increased over time in both groups. Analysis of RNA response showed a decrease of 1.5 log10 or higher in both treatment groups. Overall, 400 patients in the ritonavir group and 338 patients in the indinavir group developed at least one grade 3/serious new adverse event during follow-up (relative risk, 1.48; 95% CI, 1.28-1.72; p = 0.0001). Favorable CD4+ cell and RNA responses at 24 and 48 weeks were observed in both groups of patients remaining on treatment. Indinavir showed slightly better effects in sustaining RNA, CD4+ cell, and body weight responses. Ritonavir and indinavir results were comparable in terms of clinical outcome (survival and AIDS-defining events).

AIDS-related focal brain lesions in the era of highly active antiretroviral therapy

OBJECTIVE

To compare the years since the introduction of highly active antiretroviral therapy (HAART) with the pre-HAART era for trends in the proportions of HIV-related focal brain lesion-causing disorders.

METHODS

A prospective, single-center study of all consecutive HIV-infected patients with a neurologic presentation and focal brain lesions observed between January 1991 and December 1998 was undertaken.

RESULTS

The major diagnoses in the 281 patients were toxoplasmic encephalitis (36.4%), primary CNS lymphoma (26.7%), progressive multifocal leukoencephalopathy (18.2%), and focal HIV encephalopathy (5.0%). During the HAART period, patients were less likely to be male, contracted HIV more often through heterosexual exposure, had fewer previous AIDS-defining events, received antiToxoplasma prophylaxis less frequently, had a CD4+ lymphocyte count 2.5 times higher, and had diagnosis based more often on PCR assays from CSF, reducing the need for brain biopsy and enhancing the likelihood of in vivo diagnosis. Using all patients hospitalized per year as reference population, the risk of focal brain lesions strongly increased during the pre-HAART period and declined significantly during the HAART years. In the HAART period a relevant decline of primary CNS lymphoma was found (OR for 1998, 0.25; p for trend = 0.03) and the effect of progressive calendar year was confirmed on multivariable analysis (OR, 0.52; 95% CI, 0.28 to 0.97). The frequency of toxoplasmic encephalitis decreased during the pre-HAART era and was stable afterwards. For progressive multifocal leukoencephalopathy, a slight increase was seen over time. Focal white matter lesions without enhancement or mass effect increased between 1991 and 1998.

CONCLUSIONS

During the HAART era, AIDS-related primary CNS lymphoma showed a strong decline, toxoplasmic encephalitis remained stable, and progressive multifocal leukoencephalopathy showed a slight increase. Focal white matter lesions without mass effect or contrast enhancement became the most frequently seen focal brain lesion. For differential diagnosis, PCR-based assays from CSF led to a shift from brain biopsy toward a minimally invasive approach with an augmented likelihood of in vivo diagnosis.

Synthesis, structure, and antitumor activity of a novel tetranuclear titanium complex

The coordination complex cyclo-tetrakis[bis(1-phenyl-3-methyl-4-benzoylpyrazolon-5-ato++ +)mu-o xotitanium(IV)] has been synthesized and characterized with IR and NMR spectroscopies and X-ray diffraction. The core of this species consists of an eight-membered Ti-mu-oxo ring with alternate short-long Ti-O bond lengths. Besides these two O ligands, each metal is bound octahedrally to four O atoms from two chelating 1-phenyl-3-methyl-4-benzoylpyrazolon-5-ato anions. Several sets of Ti-O bond lengths are present: the shortest are the two Ti-O(oxo) (which are cis to each other), the longest are the two Ti-O(acyl) (cis to each other), and the two Ti-O(pyrazolonato) (trans to each other) are intermediate. The beta-diketonate ligand asymmetry, a feature considered essential in other antitumor Ti compounds, induces the short-long Ti-O(oxo) sequence of bond lengths. The antitumor activity of this compound, encapsulated in a dipalmitoylphosphatidylcholine liposome, has been studied in vitro using TA-3 (mouse mammary adenocarcinoma), HEP-2 (human epithelial larynx carcinoma), and VERO (African green monkey kidney) cell lines and in vivo in CF-1 and AJ female mice ip inoculated with TA-3. In vitro cytotoxicity is greater for TA-3 than for HEP-2 and null for VERO cell lines. In vivo results show a marked increase in survival time (T/C = 293% for AJ and 208% for CF-1), whereas tumor weight decrease was observed for CF-1-treated mice. These results suggest the Ti complex-liposome system may be promising as an antitumor drug.