High-throughput discovery of organic cages and catenanes using computational screening fused with robotic synthesis.

Supramolecular synthesis is a powerful strategy for assembling complex molecules, but to do this by targeted design is challenging. This is because multicomponent assembly reactions have the potential to form a wide variety of products. High-throughput screening can explore a broad synthetic space, but this is inefficient and inelegant when applied blindly. Here we fuse computation with robotic synthesis to create a hybrid discovery workflow for discovering new organic cage molecules, and by extension, other supramolecular systems. A total of 78 precursor combinations were investigated by computation and experiment, leading to 33 cages that were formed cleanly in one-pot syntheses. Comparison of calculations with experimental outcomes across this broad library shows that computation has the power to focus experiments, for example by identifying linkers that are less likely to be reliable for cage formation. Screening also led to the unplanned discovery of a new cage topology-doubly bridged, triply interlocked cage catenanes.

Pharmacokinetic evaluation of the effects of ribavirin on zidovudine triphosphate formation: ACTG 5092s Study Team.

OBJECTIVES: Ribavirin (RBV) is used for the treatment of hepatitis C virus (HCV) infection in subjects with HIV-1 infection who may require antiretroviral treatment (ART) with nucleoside reverse transcriptase inhibitors including zidovudine (ZDV). We sought to investigate the potential antagonism between RBV and ZDV by evaluating the impact of RBV on the formation of intracellular ZDV triphosphate (TP) in HIV-infected patients receiving ZDV who were treated for HCV infection. METHODS: Serial plasma and intracellular ZDV TP pharmacokinetics (PK) were determined in 14 subjects at entry (within 2 weeks prior to RBV administration) and at 8 weeks following initiation of RBV. Intracellular ZDV TP in peripheral blood mononuclear cells (PBMC) was quantified by a validated cartridge/liquid chromatography/tandem mass spectrometry method. PK exposure was estimated from the steady-state area under the concentration vs time curve (AUC(0-12 h)) in plasma and PBMC. RESULTS: Ribavirin did not have a statistically significant impact on ZDV TP AUC(0-12 h), plasma ZDV AUC(0-12 h) or the ratio of ZDV TP AUC(0-12 h) to plasma ZDV AUC(0-12 h), although there was a trend towards an increase post-RBV ratio compared with pre-RBV. There was extensive variability in the ZDV TP AUC(0-12 h). CONCLUSIONS: Ribavirin did not inhibit formation of ZDV TP in PBMC in 14 patients receiving ZDV as part of ART and RBV-based HCV therapy for 8 weeks. These results are consistent with those of a previously published limited study in seven subjects. These PK findings should be weighed carefully against emerging clinical reports of significant anaemia associated with combination ZDV and high-dose RBV therapy.

Changes in weight and lean body mass during highly active antiretroviral therapy.

BACKGROUND: Few studies have prospectively evaluated the impact of highly active antiretroviral therapy (HAART) on body weight and lean body mass (LBM) or explored the impact of baseline immunologic or virological changes on these parameters. METHODS: Adult AIDS Clinical Trials Group (ACTG) protocol 892 was a prospective, 48-week, multisite observational study of body composition conducted during 1997-2000 among 224 antiretroviral-naive and antiretroviral-experienced subjects coenrolled into various adult ACTG antiretroviral studies. Assessments included human immunodeficiency virus type 1 (HIV-1) RNA load (by polymerase chain reaction); T lymphocyte subset analysis; Karnofsky score; height (baseline only); weight, LBM, and fat (by bioelectrical impedance analysis); and functional performance (by questionnaire). RESULTS: Overall, only modest median increases in body weight (1.9 kg) and LBM (0.6 kg) occurred after 16 weeks of therapy. Significantly greater median increases in body weight (2.1 vs. 0.5 kg; P=.045) occurred in subjects who achieved virological suppression (HIV-1 RNA load, <500 copies/mL) at week 16 than in subjects who did not. Subjects who were antiretroviral naive at baseline gained more weight (median increase in body weight, 2.6 vs. 0.0 kg; P<.001) and LBM (1.0 vs. 0.1 kg; P=.002) after 16 weeks of treatment than did subjects who were antiretroviral experienced. Subjects with lower baseline CD4 cell counts (<200 cells/mm3) and subjects with higher baseline HIV-1 RNA loads (> or =100,000 copies/mL) were more likely to show increases in LBM of >1.5 kg (P=.013 and P=.005, respectively). CONCLUSIONS: HAART had modestly favorable effects on body composition, particularly in patients with greater pretreatment immunocompromise and virological compromise. The difference between antiretroviral-naive and antiretroviral-experienced subjects with regard to the ability to achieve increased body weight and LBM requires more study.

The safety and efficacy of adefovir dipivoxil in patients with advanced HIV disease: a randomized, placebo-controlled trial.

OBJECTIVE: Efficacy and safety of adefovir dipivoxil (adefovir) added to background antiretroviral therapy in advanced HIV disease. DESIGN: Randomized, double-blind, placebo-controlled multicenter trial. SETTING: Fifteen clinical trial units providing HIV primary care. PARTICIPANTS: Adults with CD4 cell count < or = 100 x 10(6)/l, or 101-200 x 10(6)/l with prior nadir < or = 50 x 10(6)/l. INTERVENTIONS: Oral adefovir or placebo 120 mg once daily. MAIN OUTCOME MEASURES: Survival, cytomegalovirus (CMV) disease, plasma HIV-RNA, CD4 cell count, grade 4 drug toxicity, permanent drug discontinuation due to toxicity. RESULTS: Among the 253 patients assigned adefovir and the 252 assigned placebo, respectively, 17 and 16 died (P = 0.88), and four and eight experienced CMV disease (P = 0.25). Mean change in log(10) plasma HIV-RNA in the adefovir and placebo groups, respectively, was 0.09 and -0.03 copies/ml at 6 months (P = 0.22) and 0.06 and -0.02 at 12 months (P = 0.87). Changes in CD4 cell counts were not different between groups. At 12 months the cumulative percent with proximal renal tubular dysfunction (PRTD) was 17% in the adefovir group and 0.4% in the placebo group (P < 0.0001, log rank test). Median time to resolution of PRTD was 15 weeks among patients assigned adefovir, and 16% of patients did not resolve completely 41 weeks after onset. More drug discontinuations occurred in the adefovir group than in the placebo group. CONCLUSIONS: No virologic or immunologic benefit was observed when adefovir was added to background antiretroviral therapy in advanced HIV disease, and adefovir was associated with considerable nephrotoxicity. This study does not support the use of adefovir for treatment of advanced HIV disease in pretreated patients.

The closeout process for a clinical trial terminated early for lagging enrollment and inadequate follow-up.

Closeout of a clinical trial, whether carried out to its original completion of full accrual and attendant follow-up or stopped prematurely because of early indications of efficacy or adverse toxicity, presents challenges in many areas. Closing a clinical trial that fails to adequately accrue and/or successfully follow up patients may exacerbate these problems. The issues involved in the early termination of the Low-Dose Oral Alpha Interferon Trial are described. Control Clin Trials 2001;22:49-55

A multicenter, randomized, controlled trial of three preparations of low-dose oral alpha-interferon in HIV-infected patients with CD4+ counts between 50 and 350 cells/mm(3). Division of AIDS Treatment Research Initiative (DATRI) 022 Study Group.

To evaluate the effectiveness of low-dose oral alpha-interferon (alpha-IFN), 247 HIV-infected study subjects received placebo, Alferon LDO, Veldona, or Ferimmune in a randomized, double-blind trial. Subjects had CD4+ counts between 50 and 350 cells/mm3 and HIV-related symptoms at entry. Study subjects rated the severity of eight symptoms using a symptom burden index (SBI). Study endpoints included changes in SBI, weight, CD4+ count, and Karnofsky score between baseline and the 24-week visit. The SBI outcome and weight were measured in 99 and 106 study subjects, respectively, at both the baseline and 24-week visits. Baseline SBI scores ranged from 5.4 to 7.9 in the four arms. No clinically important or statistically significant differences were found among the four arms with regard to SBI or weight change over the 24-week period. There were also no significant differences among the arms for CD4+ cell count and Karnofsky score. Few adverse reactions were noted in any arm, and there were no significant differences between arms. Although the trial was designed to enroll 560 study subjects and was prematurely terminated because of slow accrual and discontinuations of participants, the small differences among the arms in the primary and secondary endpoints do not support claims of efficacy for the measures studied.

A randomized, placebo-controlled trial of the safety and efficacy of oral ganciclovir for prophylaxis of cytomegalovirus disease in HIV-infected individuals. Terry Beirn Community Programs for Clinical Research on AIDS.

OBJECTIVE: Evaluate safety and efficacy of oral ganciclovir (GCV) for preventing cytomegalovirus (CMV) disease in HIV-infected persons at high risk for CMV disease. DESIGN: Double-blind, placebo-controlled, randomized clinical trial in primary care clinics and private practice offices specializing in the care of people with HIV. Interventions were oral GCV (1000 mg three times/day) or placebo. Protocol amendment allowed switch to open-label oral GCV. Main outcome measures were confirmed CMV retinal or gastrointestinal mucosal disease, and death. The study enrolled 994 people co-infected with CMV and HIV, with at least one CD4 count recorded < 100 x 10(6) cells/l. RESULTS: At study completion (15 months median follow-up), CMV event rates in the oral GCV and control groups were 13.1 and 14.6 per 100 person years, respectively, a hazard ratio (HR) of 0.92 [95% confidence interval (CI), 0.65-1.27; P = 0.6]. At protocol amendment event rates were 12.7 and 15.0, respectively (HR, 0.85; 95% CI, 0.56-1.30; P = 0.45). At study completion, event rates for death were 26.6 and 32.0 (HR, 0.84; P = 0.09), and at protocol amendment were 18.9 and 19.6 (HR, 0.95; P = 0.78), respectively. At protocol amendment for the CMV endpoint, the oral GCV treatment effect was associated with baseline use of didanosine (ddI). For patients taking ddI at randomization, HR was 7.48 (P = 0.02). For patients not taking ddI, HR was 0.62 (P = 0.04). These HR were statistically different (P = 0.0006). CONCLUSIONS: In our study, 3 g/day oral GCV did not significantly reduce CMV disease incidence, but there was a suggestion of a death-rate reduction. Furthermore, results suggest that oral GVC decreased risk of CMV disease in patients not prescribed ddI, and increased risk in those prescribed ddI. For the CMV endpoint, our study differs markedly from the only similar study, although for the death endpoint, a combined analysis of studies indicated significant reduction in death rate.

Weekly fluconazole for the prevention of mucosal candidiasis in women with HIV infection. A randomized, double-blind, placebo-controlled trial. Terry Beirn Community Programs for Clinical Research on AIDS.

BACKGROUND: Candidiasis is a frequent complication of infection with the human immunodeficiency virus (HIV); however, few data exist about the natural history, prevention, and treatment of mucosal candidiasis in women. OBJECTIVE: To evaluate the safety and effectiveness of weekly fluconazole prophylaxis for mucosal candidiasis in women infected with HIV. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: 14 sites participating in the Community Programs for Clinical Research on AIDS (CPCRA). PATIENTS: 323 women with HIV infection and CD4+ cell counts of 300 cells/mm3 or less. INTERVENTION: 200 mg of fluconazole per week or placebo. Open-label fluconazole for candidiasis prophylaxis was permitted after two oropharyngeal or vaginal episodes or one esophageal episode. MEASUREMENTS: Development of mucosal candidiasis, clinical and in vitro resistance of Candida species to fluconazole, survival, and adverse events. RESULTS: After a median follow-up of 29 months, 72 of 162 patients receiving fluconazole and 93 of 161 patients receiving placebo had at least one episode of candidiasis (relative risk [RR], 0.56 [95% Cl, 0.41 to 0.77); P < 0.001). Weekly fluconazole was effective in preventing oropharyngeal candidiasis (RR, 0.50 [Cl, 0.33 to 0.74]; P < 0.001) and vaginal candidiasis (RR, 0.64 [Cl, 0.40 to 1.00]; P = 0.05) but not esophageal candidiasis (RR, 0.91 [Cl, 0.48 to 1.72]; P > 0.2). Relative risks were similar for women who had a history of mucosal candidiasis (RR, 0.5 [Cl, 0.35 to 0.75]) and those who did not (RR, 0.69 [Cl, 0.35 to 1.34]). Absolute risk reduction for patients with a history of infection was 25.6 per 100 person-years, which is more than twice the reduction of 11.2 per 100 person-years seen in patients with no history of infection. This difference reflects the higher risk of patients who previously had an infection. Candida albicans was not usually resistant to fluconazole in vaginal specimens in clinical or in vitro settings; such resistance occurred in less than 5% of patients in each group. CONCLUSIONS: Weekly fluconazole (200 mg) seems to be safe and effective in preventing oropharyngeal and vaginal candidiasis. This regimen has a useful role in the management of HIV-infected women who are at risk for recurrent mucosal candidiasis.

Early induction of parturition and initiation of lactation in sheep.

Dexamethasone and estradiol benzoate were used to induce parturition in ewes at about day 120 of gestation as part of a program to reduce the time taken to progeny-test carpet-wool rams by evaluating the birthcoats of their offspring. Ten ewes received 5 injections of 12 mg dexamethasone over 2.5 days commencing on day 117. Eight lambed 3.1 +/- 0.53 days after the final injection. Of 14 ewes which received 20 mg estradiol benzoate on day 118, three delivered lambs, 2.0 +/- 0.41 days after injection. All lambs were born dead or died within 2 hours of birth. Following parturition all ewes came into lactation. The dexamethasone group produced more colostrum, with higher total solids content than the estradiol group. However, the volume was less than in a control group which lambed at full term. It was concluded that dexamethasone could be used successfully to induce parturition at 120 days and that onset of lactation was similar to that which occurs at full term.