Efficacy and effect on lipid profiles of switching to ainuovirine-based regimen versus continuing efavirenz-based regimen in people with HIV-1: 24-week results from a real-world, retrospective, multi-center cohort study

Ainuovirine (ANV), a novel non-nucleoside reverse-transcriptase inhibitor (NNRTI), was approved in China in 2021. In a previous randomized phase 3 trial, ANV demonstrated non-inferior efficacy relative to efavirenz (EFV) and was associated with lower rates of dyslipidemia. In this study, we aimed to explore lipid changes in treatment-experienced people with human immunodeficiency virus (HIV)-1 (PWH) switching to ANV from EFV in real world. At week 24, 96.65% of patients in the ANV group and 93.25% in the EFV group had HIV-1 RNA levels below the limit of quantification (LOQ). Median changes from baseline in CD4 +T cell counts (37.0 vs 36.0 cells/µL, P = 0.886) and CD4+/CD8 +ratio (0.03 vs 0.10, P = 0.360) were similar between the two groups. The ANV group was superior to the EFV group in mean changes in total cholesterol (TC, -0.06 vs 0.26 mmol/L, P = 0.006), triglyceride (TG, -0.6 vs 0.14 mmol/L, P < 0.001), high-density lipoprotein cholesterol (HDL-C, 0.09 vs 0.08 mmol/L, P = 0.006), and low-density lipoprotein cholesterol (LDL-C, -0.18 vs 0.29 mmol/L, P < 0.001) at week 24. We also observed that a higher proportion of patients demonstrated improved TC (13.55% vs 4.45%, P = 0.015) or LDL-C (12.93% vs 6.89%, P = 0.017), and a lower proportion of patients showed worsened LDL-C (5.57% vs 13.52%, P = 0.017) with ANV than with EFV at week 24. In conclusion, we observed good efficacy and favorable changes in lipids in switching to ANV from EFV in treatment-experienced PWH in real world, indicating a promising switching option for PWH who may be more prone to metabolic or cardiovascular diseases.

7,8-Dihydroxy Efavirenz Is Not as Effective in CYP46A1 Activation In Vivo as Efavirenz or Its 8,14-Dihydroxy Metabolite

High dose (S)-efavirenz (EFV) inhibits the HIV reverse transcriptase enzyme and is used to lower HIV load. Low-dose EFV allosterically activates CYP46A1, the key enzyme for cholesterol elimination from the brain, and is investigated as a potential treatment for Alzheimer's disease. Simultaneously, we evaluate EFV dihydroxymetabolites for in vivo brain effects to compare with those of (S)-EFV. We have already tested (rac)-8,14dihydroxy EFV on 5XFAD mice, a model of Alzheimer's disease. Herein, we treated 5XFAD mice with (rac)-7,8dihydroxy EFV. In both sexes, the treatment modestly activated CYP46A1 in the brain and increased brain content of acetyl-CoA and acetylcholine. Male mice also showed a decrease in the brain levels of insoluble amyloid β40 peptides. However, the treatment had no effect on animal performance in different memory tasks. Thus, the overall brain effects of (rac)-7,8dihydroxy EFV were weaker than those of EFV and (rac)-8,14dihydroxy EFV and did not lead to cognitive improvements as were seen in treatments with EFV and (rac)-8,14dihydroxy EFV. An in vitro study assessing CYP46A1 activation in co-incubations with EFV and (rac)-7,8dihydroxy EFV or (rac)-8,14dihydroxy EFV was carried out and provided insight into the compound doses and ratios that could be used for in vivo co-treatments with EFV and its dihydroxymetabolite.

Optimizing Moxifloxacin Dose in MDR-TB Participants with or without Efavirenz Coadministration Using Population Pharmacokinetic Modeling

Moxifloxacin is included in some treatment regimens for drug-sensitive tuberculosis (TB) and multidrug-resistant TB (MDR-TB). Aiming to optimize dosing, we described moxifloxacin pharmacokinetic and MIC distribution in participants with MDR-TB. Participants enrolled at two TB hospitals in South Africa underwent intensive pharmacokinetic sampling approximately 1 to 6 weeks after treatment initiation. Plasma drug concentrations and clinical data were analyzed using nonlinear mixed-effects modeling with simulations to evaluate doses for different scenarios. We enrolled 131 participants (54 females), with median age of 35.7 (interquartile range, 28.5 to 43.5) years, median weight of 47 (42.0 to 54.0) kg, and median fat-free mass of 40.1 (32.3 to 44.7) kg; 79 were HIV positive, 29 of whom were on efavirenz-based antiretroviral therapy. Moxifloxacin pharmacokinetics were described with a 2-compartment model, transit absorption, and elimination via a liver compartment. We included allometry based on fat-free mass to estimate disposition parameters. We estimated an oral clearance for a typical patient to be 17.6 L/h. Participants treated with efavirenz had increased clearance, resulting in a 44% reduction in moxifloxacin exposure. Simulations predicted that, even at a median MIC of 0.25 (0.06 to 16) mg/L, the standard daily dose of 400 mg has a low probability of attaining the ratio of the area under the unbound concentration-time curve from 0 to 24 h to the MIC (fAUC_0-24)/MIC target of >53, particularly in heavier participants. The high-dose WHO regimen (600 to 800 mg) yielded higher, more balanced exposures across the weight ranges, with better target attainment. When coadministered with efavirenz, moxifloxacin doses of up to 1,000 mg are needed to match these exposures. The safety of higher moxifloxacin doses in clinical settings should be confirmed.

Do anti-HIV drugs pose a threat to photosynthetic microorganisms?

We investigated the occurrence and risk assessment of three anti-HIV drugs [(tenofovir (TNF), lamivudine (LMV) and efavirenz (EFV)] in urban rivers from Curitiba (Brazil), as well as the individual and combined effects of their environmental representative concentrations on the freshwater periphytic species Synechococcus elongatus (Cyanobacteria) and Chlorococcum infusionum (Chlorophyta). The three studied drugs, except TNF, were found in 100% of the samples, and concentrations in samples ranged from 165 to 412 ng TNF L^-1, 173-874 ng LMV L^-1 and 13-1250 ng EFV L^-1. Bioassays using artificial contaminated water showed that at environmental concentrations, TNF and LMV did not represent environmental risks to the studied photosynthetic organisms. However, EFV was shown to be toxic, affecting photosynthesis, respiration, and oxidative metabolism. The studied drugs demonstrated interactive effects. Indeed, when submitted to the combination of TNF and LMV, decreased photosynthesis was observed in C. infusionum cells. Moreover, the toxic effects of EFV were amplified in both species when TNF and/or LMV were added to the media. The simultaneous presence of TNF, LMV and EFV in environmental matrices associated with their interactive effects, lead to increased toxicological effects of water contaminated by anti-HIV drugs and thus to an ecological threat to photosynthetic microorganisms.

Increased Acetylcholine Levels and Other Brain Effects in 5XFAD Mice after Treatment with 8,14-Dihydroxy Metabolite of Efavirenz

Efavirenz (EFV), an FDA-approved anti-HIV drug, has off-target binding to CYP46A1, the CNS enzyme which converts cholesterol to 24-hydroxycholesterol. At small doses, EFV allosterically activates CYP46A1 in mice and humans and mitigates some of the Alzheimer's disease manifestations in 5XFAD mice, an animal model. Notably, in vitro, all phase 1 EFV hydroxymetabolites activate CYP46A1 as well and bind either to the allosteric site for EFV, neurotransmitters or both. Herein, we treated 5XFAD mice with 8,14-dihydroxyEFV, the binder to the neurotransmitter allosteric site, which elicits the highest CYP46A1 activation in vitro. We found that treated animals of both sexes had activation of CYP46A1 and cholesterol turnover in the brain, decreased content of the amyloid beta 42 peptide, increased levels of acetyl-CoA and acetylcholine, and altered expression of the brain marker proteins. In addition, male mice had improved performance in the Barnes Maze test and increased expression of the acetylcholine-related genes. This work expands our knowledge of the beneficial CYP46A1 activation effects and demonstrates that 8,14-dihydroxyEFV crosses the blood-brain barrier and has therapeutic potential as a CYP46A1 activator.

Prevalence and predictors of glucose metabolism disorders among People Living with HIV on combination antiretroviral therapy

Objective

We investigated prevalence and predictors of glucose metabolism disorders (GMDs) among People Living with HIV (PLWH) on efavirenz- and atazanavir/ritonavir-based combination antiretroviral therapy (cART).

Methods

This cross-sectional study involved adult PLWH on efavirenz- (n = 240) and atazanavir/ritonavir-based (n = 111) cART. The prevalence of GMDs was determined by fasting serum glucose, insulin, and homeostasis model assessment. A logistic regression model was used to determine predictors.

Results

The overall prevalence of GMDs for all regimens was 27.6% (97/351) [95% CI 23.0–32.6%] s, with 31.1% (75/240) [95% CI 25.4–37.5%] for efavirenz-based and 19.8% (22/111) [95% CI 12.9–28.5%)] for atazanavir/ritonavir-based cART group. The prevalence of impaired fasting glycemia was significantly higher (p = 0.026) in the efavirenz- [(15.4%) (37/240); 95%CI (11.1–20.6%)] than atazanavir/ritonavir-based [(7.2%) (8/111), (95%CI (3.2–13.7%)] cART. However, no significant difference was observed in the prevalence of diabetes mellitus and insulin resistance between the two regimens. Age ≥46 years old and specific type of ARV contained in cART, such as TDF, were independent predictors of GMD in both groups. Whereas the male gender and BMI category were predictors of GMDs among EFV-based cART group, AZT- and ABC- containing regimens and triglyceride levels were predictors in the ATV/r-based group.

Conclusions

GMDs were highly prevalent among adults on EFV- than ATV/r-based cARTs. Age ≥46 years and TDF-containing cARTs are common predictors in both regimens. Close monitoring for impaired fasting glucose during long-term EFV-based cART is recommended for early diagnosis of type-2 diabetes and management.

Dolutegravir as First- or Second-Line Treatment for HIV-1 Infection in Children

BACKGROUND

Children with human immunodeficiency virus type 1 (HIV-1) infection have limited options for effective antiretroviral treatment (ART).

METHODS

We conducted an open-label, randomized, noninferiority trial comparing three-drug ART based on the HIV integrase inhibitor dolutegravir with standard care (non-dolutegravir-based ART) in children and adolescents starting first- or second-line ART. The primary end point was the proportion of participants with virologic or clinical treatment failure by 96 weeks, as estimated by the Kaplan-Meier method. Safety was assessed.

RESULTS

From September 2016 through June 2018, a total of 707 children and adolescents who weighed at least 14 kg were randomly assigned to receive dolutegravir-based ART (350 participants) or standard care (357). The median age was 12.2 years (range, 2.9 to 18.0), the median weight was 30.7 kg (range, 14.0 to 85.0), and 49% of the participants were girls. By design, 311 participants (44%) started first-line ART (with 92% of those in the standard-care group receiving efavirenz-based ART), and 396 (56%) started second-line ART (with 98% of those in the standard-care group receiving boosted protease inhibitor-based ART). The median follow-up was 142 weeks. By 96 weeks, 47 participants in the dolutegravir group and 75 in the standard-care group had treatment failure (estimated probability, 0.14 vs. 0.22; difference, -0.08; 95% confidence interval, -0.14 to -0.03; P = 0.004). Treatment effects were similar with first- and second-line therapies (P = 0.16 for heterogeneity). A total of 35 participants in the dolutegravir group and 40 in the standard-care group had at least one serious adverse event (P = 0.53), and 73 and 86, respectively, had at least one adverse event of grade 3 or higher (P = 0.24). At least one ART-modifying adverse event occurred in 5 participants in the dolutegravir group and in 17 in the standard-care group (P = 0.01).

CONCLUSIONS

In this trial involving children and adolescents with HIV-1 infection who were starting first- or second-line treatment, dolutegravir-based ART was superior to standard care. (Funded by ViiV Healthcare; ODYSSEY ClinicalTrials.gov number, NCT02259127; EUDRACT number, 2014-002632-14; and ISRCTN number, ISRCTN91737921.).

Resistance Testing for Management of HIV Virologic Failure in Sub-Saharan Africa : An Unblinded Randomized Controlled Trial

BACKGROUND

Virologic failure in HIV predicts the development of drug resistance and mortality. Genotypic resistance testing (GRT), which is the standard of care after virologic failure in high-income settings, is rarely implemented in sub-Saharan Africa.

OBJECTIVE

To estimate the effectiveness of GRT for improving virologic suppression rates among people with HIV in sub-Saharan Africa for whom first-line therapy fails.

DESIGN

Pragmatic, unblinded, randomized controlled trial. (ClinicalTrials.gov: NCT02787499).

SETTING

Ambulatory HIV clinics in the public sector in Uganda and South Africa.

PATIENTS

Adults receiving first-line antiretroviral therapy with a recent HIV RNA viral load of 1000 copies/mL or higher.

INTERVENTION

Participants were randomly assigned to receive standard of care (SOC), including adherence counseling sessions and repeated viral load testing, or immediate GRT.

MEASUREMENTS

The primary outcome of interest was achievement of an HIV RNA viral load below 200 copies/mL 9 months after enrollment.

RESULTS

The trial enrolled 840 persons, divided equally between countries. Approximately half (51%) were women. Most (72%) were receiving a regimen of tenofovir, emtricitabine, and efavirenz at enrollment. The rate of virologic suppression did not differ 9 months after enrollment between the GRT group (63% [263 of 417]) and SOC group (61% [256 of 423]; odds ratio [OR], 1.11 [95% CI, 0.83 to 1.49]; P = 0.46). Among participants with persistent failure (HIV RNA viral load ≥1000 copies/mL) at 9 months, the prevalence of drug resistance was higher in the SOC group (76% [78 of 103] vs. 59% [48 of 82]; OR, 2.30 [CI, 1.22 to 4.35]; P = 0.014). Other secondary outcomes, including 9-month survival and retention in care, were similar between groups.

LIMITATION

Participants were receiving nonnucleoside reverse transcriptase inhibitor-based therapy at enrollment, limiting the generalizability of the findings.

CONCLUSION

The addition of GRT to routine care after first-line virologic failure in Uganda and South Africa did not improve rates of resuppression.

PRIMARY FUNDING SOURCE

The President's Emergency Plan for AIDS Relief and the National Institute of Allergy and Infectious Diseases.

Brief Report: Vaginal Viral Shedding With Undetectable Plasma HIV Viral Load in Pregnant Women Receiving 2 Different Antiretroviral Regimens: A Randomized Clinical Trial

BACKGROUND

Pregnant women using antiretrovirals (ARVs) may have persistent vaginal viral shedding, which could be associated with sexual and perinatal HIV transmission. However, there are scant data on vaginal viral load (VVL) in pregnant women with undetectable plasma viral load (PVL).

METHODS

This study was a post hoc analysis of an open-label randomized trial to evaluate the virologic response of 2 ART regimens. The participants were ART-naive women living with HIV initiating ART regimens between 20 and 36 weeks of pregnancy recruited at 19 clinical sites in 6 countries. Participants were randomized to receive 400 mg of raltegravir 2 times a day or 600 mg of efavirenz 4 times a day in addition to 150 mg of lamivudine and 300 mg of zidovudine 2 times a day. VVL and PVL tests were performed at every study visit. The primary outcome measures were HIV-1 PVL and VVL at maternal study week 4 and rates of perinatal HIV transmission.

RESULTS

A total of 408 were enrolled, of whom 323 had VVL samples 4 weeks after enrollment and were included in this analysis. Among women with undetectable/nonquantifiable PVL during ART, the overall rate of quantifiable VVL at week 4 was 2.54% (7/275). Of the 275 with nonquantifiable PVL, 99.1% (115/116) and 96.2% (153/159) had nonquantifiable VVL in the efavirenz and raltegravir arms, respectively. None of the 7 women with quantifiable VVL at the week 4 study visit transmitted HIV to their infants.

CONCLUSIONS

Detectable VVL in pregnant women with undetectable/nonquantifiable PVL while receiving ART was rare and not associated with perinatal HIV transmission.

Design and synthesis of Grp94 selective inhibitors based on Phe199 induced fit mechanism and their anti-inflammatory effects

Glucose-regulated protein 94 (Grp94), a member of the Heat shock protein 90 (Hsp90) family, is implicated in many human diseases, including cancer, neurodegeneration, inflammatory, and infectious diseases. Here, we describe our effort to design and develop a new series of Grp94 inhibitors based on Phe199 induced fit mechanism. Using an alkynyl-containing inhibitor as a starting point, we developed compound 4, which showed potent inhibitory activity toward Grp94 in a fluorescence polarization-based assay. With improved physicochemical properties and suitable pharmacokinetic properties, compound 4 was advanced into in vivo bioactivity evaluation. In a dextran sulfate sodium (DSS)-induced mouse model of ulcerative colitis (UC), compound 4 showed anti-inflammatory property and reduced the levels of pro-inflammatory cytokines (TNF-α and IL-6). Together, these findings provide evidence that this approach may be promising for further Grp94 drug development efforts.

De novo electrocardiographic abnormalities in persons living with HIV

Persons living with HIV (PLWH) may have increased incidence of cardiovascular events and longer QTc intervals than uninfected persons. We aimed to investigate the incidence and risk factors of de novo major electrocardiogram (ECG) abnormalities and QTc prolongation in well-treated PLWH. We included virologically suppressed PLWH without major ECG abnormalities, who attended the 2-year follow-up in the Copenhagen comorbidity in HIV infection (COCOMO) study. ECGs were categorized according to Minnesota Code Manual. We defined de novo major ECG abnormalities as new major Minnesota Code Manual abnormalities. Prolonged QTc was defined as QTc > 460 ms in females and QTc > 450 ms in males. Of 667 PLWH without major ECG abnormalities at baseline, 34 (5%) developed de novo major ECG abnormalities after a median of 2.3 years. After adjustment, age (RR: 1.57 [1.08-2.28] per decade older), being underweight (RR: 5.79 [1.70-19.71]), current smoking (RR: 2.34 [1.06-5.16]), diabetes (RR: 3.89 [1.72-8.80]) and protease inhibitor use (RR: 2.45 [1.27-4.74) were associated with higher risk of getting de novo major ECG abnormalities. Of PLWH without prolonged QTc at baseline, only 11 (1.6%) participants developed de novo prolonged QTc. Five percent of well-treated PLWH acquired de novo major ECG abnormalities and protease inhibitor use was associated with more than twice the risk of de novo major ECG abnormalities. De novo prolonged QTc was rare and did not seem to constitute a problem in well-treated PLWH.

Therapeutic drug monitoring study on the switch from coformulated 600-mg efavirenz, tenofovir disoproxil fumarate, and emtricitabine to coformulated 400-mg efavirenz, tenofovir disoproxil fumarate, and lamivudine among HIV-positive patients with viral suppression

OBJECTIVES

This study evaluated the efavirenz (EFV) mid-dose plasma concentration (C12), clinical efficacy, and safety after the switch to a single-tablet regimen containing tenofovir disoproxil fumarate (TDF), lamivudine (3TC), and 400-mg EFV in virally suppressed HIV-positive Taiwanese who were receiving co-formulated TDF, emtricitabine (FTC), and 600-mg EFV.

METHODS

In this single-arm, open-label study, HIV-positive adults who had undetectable plasma HIV RNA load (<50 copies/ml) for 6 months or longer while receiving co-formulated TDF, FTC, and 600-mg EFV with EFV C12 of ≥1 mg/L were enrolled. The participants were switched to co-formulated TDF, 3TC, and 400-mg EFV and followed for 24 weeks. The primary endpoint was the proportion of participants with EFV C12 ≥ 1 mg/L at Week 4. The secondary endpoints included virologic response and change of CD4 lymphocyte count up to Week 24. Specific adverse effects associated with EFV were recorded before and after the switch.

RESULTS

From December 2018 to January 2019, 50 participants were enrolled. EFV C12 remained ≥1 mg/L in 48 (96.0%) participants with a median reduction of 38.9% (interquartile range 29.0-44.4) at Week 4 after switch. All participants had undetectable plasma HIV RNA by Week 12, whereas 96.0% of them remained so at Week 24. Significant increases of CD4 lymphocyte count were observed at Weeks 12 and 24. Thirty-three participants (66.0%) reported improvement of pre-existing adverse effects.

CONCLUSION

Switch to coformulated TDF, 3TC, and 400-mg EFV in virally suppressed HIV-positive Taiwanese maintained effective EFV concentration and viral suppression while the adverse effects were reduced.

T cell derived HIV-1 is present in the CSF in the face of suppressive antiretroviral therapy

HIV cerebrospinal fluid (CSF) escape, where HIV is suppressed in blood but detectable in CSF, occurs when HIV persists in the CNS despite antiretroviral therapy (ART). To determine the virus producing cell type and whether lowered CSF ART levels are responsible for CSF escape, we collected blood and CSF from 156 neurosymptomatic participants from Durban, South Africa. We observed that 28% of participants with an undetectable HIV blood viral load showed CSF escape. We detected host cell surface markers on the HIV envelope to determine the cellular source of HIV in participants on the first line regimen of efavirenz, emtricitabine, and tenofovir. We confirmed CD26 as a marker which could differentiate between T cells and macrophages and microglia, and quantified CD26 levels on the virion surface, comparing the result to virus from in vitro infected T cells or macrophages. The measured CD26 level was consistent with the presence of T cell produced virus. We found no significant differences in ART concentrations between CSF escape and fully suppressed individuals in CSF or blood, and did not observe a clear association with drug resistance mutations in CSF virus which would allow HIV to replicate. Hence, CSF HIV in the face of ART may at least partly originate in CD4+ T cell populations.

Discovery of Potent Antiallergic Agents Based on an o-Aminopyridinyl Alkynyl Scaffold

Effective therapeutic agents are highly desired for immune-mediated allergic diseases. Herein, we report the design, synthesis, and structure-activity relationship of an o-aminopyridinyl alkyne series as novel orally bioavailable antiallergic agents, which was identified through phenotypic screening. Compound optimization yielded a highly potent compound 36, which effectively suppressed mast cell degranulation in a dose-dependent manner (IC50, 2.54 nM for RBL-2H3 cells; 48.28 nM for peritoneal mast cells (PMCs)) with a good therapeutic index. It also regulated the activation of FcεRI-mediated downstream signaling proteins in IgE/Ag-stimulated RBL-2H3 cells. In addition, 36 exhibited excellent in vivo pharmacokinetic properties and antiallergic efficacy in both passive systemic anaphylaxis (PSA) and house dust mite (HDM)-induced murine models of pulmonary allergic inflammation. Furthermore, preliminary analysis of the kinases profile identified Src-family kinases as potential targets for 36. Compound 36 may serve as a new valuable lead compound for future antiallergic drug discovery.

Point-of-Care Detection of Nonadherence to Antiretroviral Treatment for HIV-1 in Resource-Limited Settings Using Drug Level Testing for Efavirenz, Lopinavir, and Dolutegravir: A Validation and Pharmacokinetic Simulation Study

BACKGROUND

Virological failure during antiretroviral treatment (ART) may indicate the presence of drug resistance, but may also originate from nonadherence. Qualitative detection of ART components using drug level testing may be used to differentiate between these scenarios. We aimed to validate and implement qualitative point-of-care drug level tests for efavirenz (EFV), lopinavir (LPV), and dolutegravir (DTG) in rural South Africa.

METHODS

Qualitative performance of immunoassays for EFV, LPV, and DTG was assessed by calculating limit of detection (LoD), region of uncertainty, and qualitative agreement with a reference test. Minimum duration of nonadherence resulting in a negative drug level test was assessed by simulation of treatment cessation using validated population pharmacokinetic models.

RESULTS

LoD was 0.05 mg/L for EFV, 0.06 mg/L for LPV, and 0.02 mg/L for DTG. Region of uncertainty was 0.01-0.06 mg/L for EFV, 0.01-0.07 mg/L for LPV, and 0.01-0.02 mg/L for DTG. Qualitative agreement with reference testing at the LoD in patient samples was 95.2% (79/83) for EFV, 99.3% (140/141) for LPV, and 100% (118/118) for DTG. After simulated treatment cessation, median time to undetectability below LoD was 7 days [interquartile range (IQR) 4-13] for EFV, 30 hours (IQR 24-36) for LPV, and 6 days (IQR 4-7) for DTG.

CONCLUSIONS

We demonstrate that qualitative ART drug level testing using immunoassays is feasible in a rural resource-limited setting. Implementation of this technology enables reliable detection of recent nonadherence and may allow for rapid and cost-effective differentiation between patients in need for adherence counseling and patients who require drug resistance testing or alternative treatment.

Alkyne-Bridged α-Conotoxin Vc1.1 Potently Reverses Mechanical Allodynia in Neuropathic Pain Models

Several Conus-derived venom peptides are promising lead compounds for the management of neuropathic pain, with α-conotoxins being of particular interest. Modification of the interlocked disulfide framework of α-conotoxin Vc1.1 has been achieved using on-resin alkyne metathesis. Although introduction of a metabolically stable alkyne motif significantly disrupts backbone topography, the structural modification generates a potent and selective GABAB receptor agonist that inhibits Cav2.2 channels and exhibits dose-dependent reversal of mechanical allodynia in a behavioral rat model of neuropathic pain. The findings herein support the hypothesis that analgesia can be achieved via activation of GABABRs expressed in dorsal root ganglion (DRG) sensory neurons.

Standard dose raltegravir or efavirenz-based antiretroviral treatment for patients co-infected with HIV and tuberculosis (ANRS 12 300 Reflate TB 2): an open-label, non-inferiority, randomised, phase 3 trial

BACKGROUND

In patients co-infected with HIV and tuberculosis, antiretroviral therapy options are limited due to drug-drug interactions with rifampicin. A previous phase 2 trial indicated that raltegravir 400 mg twice a day or efavirenz 600 mg once a day might have similar virological efficacy in patients given rifampicin. In this phase 3 trial, we assessed the non-inferiority of raltegravir to efavirenz.

METHODS

We did a multicentre, open-label, non-inferiority, randomised, phase 3 trial at six sites in Côte d'Ivoire, Brazil, France, Mozambique, and Vietnam. We included antiretroviral therapy (ART)-naive adults (aged ≥18 years) with confirmed HIV-1 infection and bacteriologically confirmed or clinically diagnosed tuberculosis who had initiated rifampicin-containing tuberculosis treatment within the past 8 weeks. Using computerised random numbers, we randomly assigned participants (1:1; stratified by country) to receive raltegravir 400 mg twice daily or efavirenz 600 mg once daily, both in combination with tenofovir and lamivudine. The primary outcome was the proportion of patients with virological suppression at week 48 (defined as plasma HIV RNA concentration <50 copies per mL). The prespecified non-inferiority margin was 12%. The primary outcome was assessed in the intention-to-treat population, which included all randomly assigned patients (excluding two patients with HIV-2 infection and one patient with HIV-1 RNA concentration of <50 copies per mL at inclusion), and the on-treatment population, which included all patients in the intention-to-treat population who initiated treatment and were continuing allocated treatment at week 48, and patients who had discontinued allocated treatment due to death or virological failure. Safety was assessed in all patients who received at least one dose of the assigned treatment regimen. This study is registered with ClinicalTrials.gov, NCT02273765.

FINDINGS

Between Sept 28, 2015, and Jan 5, 2018, 460 participants were randomly assigned to raltegravir (n=230) or efavirenz (n=230), of whom 457 patients (230 patients in the raltegravir group; 227 patients in the efavirenz group) were included in the intention-to-treat analysis and 410 (206 patients in the raltegravir group; 204 patients in the efavirenz group) in the on-treatment analysis. At baseline, the median CD4 count was 103 cells per μL and median plasma HIV RNA concentration was 5·5 log₁₀ copies per mL (IQR 5·0-5·8). 310 (68%) of 457 participants had bacteriologically-confirmed tuberculosis. In the intention-to-treat population, at week 48, 140 (61%) of 230 participants in the raltegravir group and 150 (66%) of 227 patients in the efavirenz had achieved virological suppression (between-group difference -5·2% [95% CI -14·0 to 3·6]), thus raltegravir did not meet the predefined criterion for non-inferiority. The most frequent adverse events were HIV-associated non-AIDS illnesses (eight [3%] of 229 patients in the raltegravir group; 21 [9%] of 230 patients in the efavirenz group) and AIDS-defining illnesses (ten [4%] patients in the raltegravir group; 13 [6%] patients in the efavirenz group). 58 (25%) of 229 patients in raltegravir group and 66 (29%) of 230 patients in the efavirenz group had grade 3 or 4 adverse events. 26 (6%) of 457 patients died during follow-up: 14 in the efavirenz group and 12 in the raltegravir group.

INTERPRETATION

In patients with HIV given tuberculosis treatment, non-inferiority of raltegravir compared with efavirenz was not shown. Raltegravir was well tolerated and could be considered as an option, but only in selected patients.

FUNDING

National French Agency for AIDS Research, Ministry of Health in Brazil, Merck.

TRANSLATIONS

For the Portuguese and French translations of the abstract see Supplementary Materials section.

Growth and Neurodevelopment Outcomes in HIV-, Tenofovir-, and Efavirenz-Exposed Breastfed Infants in the PMTCT Option B+ Program in Malawi

BACKGROUND

Pregnant and breastfeeding women in Option B+ in Malawi received antiretroviral drugs (ARVs) containing efavirenz (EFV) and tenofovir disoproxil fumarate (TDF). However, effects on growth, renal, bone metabolism, and neurodevelopment of long-term exposure to low doses of these drugs through breast milk in HIV-exposed infants are unclear.

METHODS

Prospective cohorts of TDF-and-EFV-exposed and TDF-and-EFV-unexposed breastfed infants of HIV-infected and HIV-uninfected mothers in Option B+ were recruited in 2:1 ratio, respectively, followed from birth to 18 months. Infants with low birth weight, premature birth, and congenital abnormalities were excluded. Anthropometrics were assessed at birth, 6 weeks, 3, 6, 12, and 18 months. Neurodevelopment assessments used the Bayley Scales of Infant and Toddler Development III from 6 weeks. Creatinine, alkaline phosphatase, and phosphorus were assessed at 3, 6, and 12 months.

RESULTS

Of 260 HIV-and-ARV-exposed and 125 HIV-and-ARV-unexposed infants enrolled at birth, 87% and 57%, 78% and 59%, 77% and 54%, 73% and 51%, and 65% and 43% completed 6-weeks, 3, 6, 12, and 18 months visits, respectively. There were no significant differences in the mean Z-scores for length-for-age, weight-for-age, weight-for-length, mid-upper arm circumference-for-age, and head circumference-for-age between groups except at 6-weeks for length-for-age. No bone fractures occurred. Neurodevelopment outcomes were similar between groups. Of creatinine, alkaline phosphatase, and serum phosphate measurements, 1.7%, 2.6%, and 3.3% reached any toxicity levels grades 1-4, respectively, with no differences between groups.

CONCLUSION

Long-term exposure to EFV and TDF through breastfeeding in infants of HIV-infected mothers does not seem to result in significant growth, neurodevelopment, renal, or bone adverse outcomes. Data support safety of breastfeeding through 18 months within the Option B+ program.

High efavirenz levels but not neurofilament light plasma levels are associated with poor neurocognitive functioning in asymptomatic HIV patients

The aim of this study is to assess the effect of efavirenz exposure on neurocognitive functioning and investigate plasma neurofilament light (Nfl) as a biomarker for neurocognitive damage. Sub-analysis of the ESCAPE-study, a randomised controlled trial where virologically suppressed, cognitively asymptomatic HIV patients were randomised (2:1) to switch to rilpivirine or continue on efavirenz. At baseline and week 12, patients underwent an extensive neuropsychological assessment (NPA), and serum efavirenz concentration and plasma Nfl levels were measured. Subgroups of elevated (≥ 4.0 mg/L) and therapeutic (0.74 to< 4.0 mg/L) baseline efavirenz concentration were made. Differences between these groups in baseline NPA Z-scores and in delta scores after efavirenz discontinuation were assessed. Nfl level was measured using an ELISA analysis using single molecule array (Simoa) technology. Correlation of plasma NFL with NPA Z-scores was evaluated using a linear mixed model. The elevated group consisted of 6 patients and the therapeutic group of 48. At baseline, the elevated group showed lower composite Z-scores (median - 1.03; IQR 0.87 versus 0.27; 0.79. p 0.02). This effect was also seen on the subdomains verbal (p 0.01), executive functioning (p 0.02), attention (p < 0.01) and speed (p 0.01). In the switch group, the elevated group improved more on composite scores after discontinuing efavirenz (mean 0.58; SD 0.32 versus 0.22; 0.54, p 0.15). No association between plasma Nfl and composite Z-score was found. High efavirenz exposure is associated with worse cognitive functioning compared with patients with therapeutic concentrations. Plasma Nfl is not a suitable biomarker to measure cognitive damage in this group.

Prevalence of renal dysfunction among HIV infected patients receiving Tenofovir at Mulago: a cross-sectional study

BACKGROUND

There is an increasing burden of non-communicable disease globally. Tenofovir disoproxil fumarate (TDF) is the most commonly prescribed antiretroviral drug globally. Studies show that patients receiving TDF are more prone to renal dysfunction at some point in time during treatment. Evaluation of kidney function is not routinely done in most HIV public clinics. Identification of renal dysfunction is key in resource constrained settings because managing patients with end stage renal disease is costly.

METHOD

This was a cross-sectional study conducted at an outpatient clinic in 2018 involving patients on TDF for at least 6 months who were 18 years or older. Patients with documented kidney disease and pregnancy were excluded. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-Epi formula. Renal dysfunction was defined as any of the following; either eGFR< 60 mL/min/1.73m2,or proteinuria of ≥2+ on urine dipstick, glycosuria with normal blood glucose. Electrolyte abnormalities were also documented.

RESULTS

We enrolled 278 participants. One hundred sixty nine (60.8%) were females, majority 234(84.2%) were < 50 years old, 205 (73.74%) were in WHO stage 1, most participants 271(97.5%) in addition to TDF were receiving lamivudine/efavirenz. The median age was 37(IQR 29-45) years; median duration on ART was 36 (IQR 24-60) months. The prevalence of renal dysfunction was 2.52% (7/278). Most noted electrolyte abnormality was hypocalcaemia (15.44%).

CONCLUSIONS

The prevalence of renal dysfunction was low though some participants had hypocalcaemia. Screening for kidney disease should be done in symptomatic HIV infected patients on TDF.

Predictors of Discontinuation of Efavirenz as Treatment for HIV, Due to Neuropsychiatric Side Effects, in a Multi-Ethnic Sample in the United Kingdom

Efavirenz (EFV) is one of the most commonly prescribed antiretroviral therapy (ART) medications for human immunodeficiency virus-infected adults because of its favorable pharmacokinetic profile and well-documented efficacy. Nonetheless, neuropsychiatric adverse events (AE) occur in almost half of the EFV users and it is the main reason for treatment discontinuation. To identify the sociodemographic characteristics and reported neuropsychiatric side effects that placed EFV users at an increased risk of discontinuation in a multi-ethnic sample in the United Kingdom. A retrospective medical records analysis of patients prescribed EFV-containing ART in an outpatient sexual health clinic between 2010 and 2016. One hundred forty-nine medical records were reviewed. Fifty-five patients discontinued EFV within the study period. About 55.7% of patients suffered from at least one neuropsychiatric AE, the most commonly recorded symptoms were depression, vivid dreams, dizziness, and sleep disturbance. There was an inverse relationship between number of AE and EFV continuation [adjust odds ratio (OR) = 0.12; confidence interval (95% CI) = 0.03-0.44, p < .05]. Furthermore, neuropsychiatric symptoms, including depression (adjust OR = 3.01; 95% CI = 1.30-6.96, p < .05), sleep disturbance (adjust OR = 3.00; 95% CI = 1.10-8.19, p < .05), and vivid dreams (adjust OR = 2.51; 95% CI = 1.05-6.00, p < .05), were independent predictors of EFV discontinuation. The findings revealed that patients who did not experience any neuropsychiatric side effects were eight times more likely to stay on an EFV-containing regimen than those who suffered from more than three symptoms. Additionally, patients who experienced depression or sleep disturbance were at threefold elevated risk of discontinuing an EFV-based regimen. The implications for clinical practice are discussed.

Stable and Well-Organized Near-Infrared Platinum(II)-Acetylide-Based Metallacycles-Mediated Cancer Phototherapy

The development of metallacycles with high stability and intense near-infrared (NIR) absorption is important for biomedical applications. However, very few molecular design strategies have been developed on such metallacycles. Herein, we report a new series of stable and well-defined NIR-absorbing metallacycles (M1-M3) through the Pt-acetylide coordination with highly efficient photoconversion performance for cancer phototherapy. The metallacycles showed high stability and strong NIR absorption, and the absorption peaks were red shifted approximately 30 nm in comparison with their corresponding precursors. The introduction of Pt into metallacycles promotes significant photoconversions, including the singlet-to-triplet and nonradiative transitions. Moreover, the fabricated M3 nanoparticles (M3-NPs) showed favorable photoconversions into both thermal effect and singlet oxygen generation upon NIR irradiation, achieving tumor ablation. This novel design of Pt-acetylide metallacycles possesses not only complex topological architectures but also a valuable paradigm for precise cancer phototherapy, which is important for grafting stimuli-responsive functional groups into metallacycles for the development of high-performance biomedical supramolecular materials.

Association of Virologic Failure and Nonnucleoside Reverse Transcriptase Inhibitor Resistance Found in Antiretroviral-Naive Children Infected With Human Immunodeficiency Virus and Given Efavirenz-Based Treatment

Among 66 antiretroviral-naive children aged <3 years with human immunodeficiency virus (HIV) or coinfected with HIV and tuberculosis and initiating efavirenz-based antiretroviral therapy (ART), non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance was detected before ART in 5 (7.6%). Virologic failure occurred in 2 of these children; they were last tested at 16 and 24 weeks of ART. Pre-ART NNRTI resistance was not associated with virologic failure.

Recent Advances in Drug Delivery Strategies for Improved Therapeutic Efficacy of Efavirenz

BACKGROUND

Efavirenz, an anti-HIV agent, has a noticeable place in the HAART regimen for the treatment and maintenance therapy of AIDS. However, its poor water solubility accounts for hindered absorption and bio-distribution upon administration. This results in its low and variable bioavailability. To circumvent these limitations, various novel formulations of Efavirenz have been investigated in order to mitigate its drawbacks and draw out its maximum therapeutic effect.

METHODS

Numerous formulations explored to overcome the drawbacks of Efavirenz include modified/ controlled-release tablets, solid dispersions, polymeric nanoparticles, dendrimers, surface-engineered nanoparticles and various other nanoformulations. Moreover, combinatorial formulations of Efavirenz with other Anti-HIV drugs have also been reported to overcome the problem of Drug-Resistance.

RESULTS

The nanoformulation based strategies, owing to their ability to provide controlled release profile and targeted drug delivery were found to augment bioavailability, therapeutic efficacy and reduce the side effects of the Efavirenz.

CONCLUSION

This review pivots around the challenges and recent advances in the delivery of Efavirenz with particular emphasis on novel formulations including its patents.

Low doses of anti-CD3, ciclosporin A and the vitamin D analogue, TX527, synergise to delay recurrence of autoimmune diabetes in an islet-transplanted NOD mouse model of diabetes

AIMS/HYPOTHESIS

Anti-CD3 monoclonal antibodies remain the most promising immune therapy for reversing recent-onset type 1 diabetes. However, current clinical trials have revealed their major drawback, namely the narrow therapeutic window in which low doses are ineffective and higher doses that preserve functional beta cell mass cause side effects. Strategies that sidestep these limitations while preserving or improving anti-CD3's therapeutic efficiency are essential. We hypothesised that combining a potent vitamin D(3) analogue (TX527), ciclosporin A (CsA) and anti-CD3 would act to lower the dose while maintaining or even boosting therapeutic efficacy to counteract autoimmune destruction of transplanted islets.

METHODS

This study involved the use of syngeneic islet transplantation, immunofluorescence microscopy, immune phenotyping by flow cytometry, RT-PCR analysis, and in vitro and in vivo suppression assays.

RESULTS

Combination therapy with TX527, CsA and anti-CD3 was well tolerated on the basis of weight, bone and calcium variables. Remarkably, combining all three agents at sub-therapeutic doses greatly reduced recurrent autoimmune responses to a grafted islet mass (mean ± SEM: 79.5 ± 18.6 days; p < 0.01), by far exceeding the therapeutic efficacy of monotherapy (24.8 ± 7.3 days for anti-CD3) and dual therapy (25.5 ± 12.4 days for anti-CD3+CsA). Combination therapy surpassed anti-CD3 monotherapy in reducing islet infiltration by effector/memory phenotype CD8(+) T cells, as well as by reducing proinflammatory cytokine responses and increasing the frequency of T regulatory cells that were functional in vitro and in vivo, and acted in a cytotoxic T lymphocyte antigen 4-dependent manner.

CONCLUSIONS/INTERPRETATION

Combining the immunomodulatory actions of anti-CD3 mAb with CsA and the vitamin D(3) analogue, TX527, delivers therapeutic efficacy in an islet-transplanted NOD mouse model of diabetes.

Toward new therapeutics for skin and soft tissue infections: propargyl-linked antifolates are potent inhibitors of MRSA and Streptococcus pyogenes

Hospital- and community-acquired, complicated skin and soft tissue infections, often attributed to Staphylococcus aureus and Streptococcus pyogenes, present a significant health burden that is associated with increased health care costs and mortality. As these two species are difficult to discern on diagnosis and are associated with differential profiles of drug resistance, the development of an efficacious antibacterial agent that targets both organisms is a high priority. Herein we describe a structure-based drug development effort that has produced highly potent inhibitors of dihydrofolate reductase from both species. Optimized propargyl-linked antifolates containing a key pyridyl substituent display antibacterial activity against both methicillin-resistant S. aureus and S. pyogenes at MIC values below 0.1 µg/mL and minimal cytotoxicity against mammalian cells. Further evaluation against a panel of clinical isolates shows good efficacy against a range of important phenotypes such as hospital- and community-acquired strains as well as strains resistant to vancomycin.

2-Hexadecynoic acid inhibits plasmodial FAS-II enzymes and arrests erythrocytic and liver stage Plasmodium infections

Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of Plasmodium yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the inhibitory potential of the HDAs against multiple P. falciparum FAS-II (PfFAS-II) elongation enzymes was also evaluated. The highest antiplasmodial activity against blood stages of P. falciparum was displayed by 5-HDA (IC(50) value 6.6 μg/ml), whereas the 2-HDA was the only acid arresting the growth of liver stage P. yoelii infection, in both flow cytometric assay (IC(50) value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescence analysis (IC(50) 2-HDA 4.88 μg/ml, control drug atovaquone 0.37 ng/ml). 2-HDA showed the best inhibitory activity against the PfFAS-II enzymes PfFabI and PfFabZ with IC(50) values of 0.38 and 0.58 μg/ml (IC(50) control drugs 14 and 30 ng/ml), respectively. Enzyme kinetics and molecular modeling studies revealed valuable insights into the binding mechanism of 2-HDA on the target enzymes. All HDAs showed in vitro activity against Trypanosoma brucei rhodesiense (IC(50) values 3.7-31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC(50) 20.2 μg/ml), and Leishmania donovani (IC(50) values 4.1-13.4 μg/ml) with generally low or no significant toxicity on mammalian cells. This is the first study to indicate therapeutic potential of HDAs against various parasitic protozoa. It also points out that the malarial liver stage growth inhibitory effect of the 2-HDA may be promoted via PfFAS-II enzymes. The lack of cytotoxicity, lipophilic nature, and calculated pharmacokinetic properties suggests that 2-HDA could be a useful compound to study the interaction of fatty acids with these key P. falciparum enzymes.

Chemical constituents from Saussurea cordifolia

Thirty-six naturally occurring compounds, including four C(10)-acetylenic glycosides and a lignan, were isolated from the whole plants of Saussurea cordifolia. Their structures were elucidated by means of spectroscopic and chemical methods to be 4,6-decadiyne-1-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (1), 4,6-decadiyne-1-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (2), (8E)-decaene-4, 6-diyn-1-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (3), (8Z)-decaene-4,6-diyn-1-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside (4), and (2R,3S,4S)-4-(4-hydroxy-3-methoxybenzyl)-2-(5-hydroxy-3-methoxyphenyl)-3-(hydroxymethyl)-tetrahydrofuran-3-ol (5).

Leflunomide derivate FK 778 in accelerated renal injury in transgenic rat

Renal ischaemia/reperfusion (I/R) injury and hypertension represent major alloantigen-independent risk factors contributing to the development of chronic allograft nephropathy. In a model of accelerated major histocompatibility complex-independent renal injury, we evaluated the effect of leflunomide derivate - FK778 - on the progression of accelerated nephropathy. Thirty-six uninephrectomized hypertensive transgenic (m-REN-2)-27 rats received a clip on renal pedicle for 45 minutes. Animals were treated with FK778 3 mg/kg/day (I/R 3 mg, N = 12), 10 mg/kg/day (I/R 10 mg, N = 12) or placebo (N = 12) via gavage for 16 weeks. Eighteen animals were sham-operated and treated with FK778 3 mg/kg/day (sham 3 mg, N = 6), 10 mg/kg/day (sham 10 mg, N = 6) or were untreated (sham, N = 6). Proteinuria and blood pressure were evaluated throughout and the kidneys were harvested for morphological and immunohistochemical analysis at the end of the experiment. At week 16, rats with I/R injury and FK778 treatment had lower proteinuria compared with placebo-treated rats (I/R 3 mg: 48.42 +/- 26.16, I/R 10 mg 27.28 +/- 21.86 vs. Placebo: 70.13 +/- 50.19 mg/day, P < 0.05). The untreated sham group exhibited lower proteinuria compared with FK778-treated sham groups (Sham 3 mg: 24.23 +/- 10.89; Sham 10 mg: 17.37 +/- 4.13; Sham: 14.23 +/- 1.18) There was no difference in glomerulosclerosis and interstitial fibrosis among the treated groups. In the untreated animals the rate of interstitial fibrosis decline reached statistical significance (Placebo vs. Sham: 1.125 +/- 0.641 % vs. 0.250 +/- 0.500 %, P < 0.05). There was higher CD5+ leukocyte infiltration in the placebotreated group. FK778-treated rats displayed amelioration of some changes induced by the I/R injury. Our observation also suggests potential nephrotoxicity of FK778.

Prolonged Survival With FK778 (Malononitrilamide) Monotherapy After Small Bowel Transplantation: A Large Animal Study

Malononitrilamide 715 (FK778) is a new class of immunosuppressant, derived from the active metabolite of leflunomide A77 1726. We investigated the efficacy of two different immunosuppressive induction protocols with tacrolimus plus FK778 followed by FK778 monotherapy. In a swine model of small bowel transplantation, we observed three groups, divided by different therapy regimens: group 1 (n = 5): no immunosuppressant (control group); group 2 (n = 10): oral tacrolimus (from postoperative day [POD] 0 to 30) and FK778 (from POD 0 to 60); group 3 (n = 8): oral tacrolimus, as group 2, and FK778 (from POD 7 to POD 60). Median survival was 11, 60, and 21 days in groups 1, 2, and 3, respectively. In group 1 all animals died of acute rejection; in group 2 the causes of death were technical complication (n = 1) and sepsis (n = 1); in group 3, one animal died from obstruction, two from pneumonia, one from peritonitis, one from sepsis. Group 2 accounted for 0.5 infection episode/animal versus 0.62 in group 3 (P < .05). Acute rejection was absent or mild in 66% and 75% of group 3 and 2 biopsies, respectively (P < .05). The D-xylose absorption curves from groups 2 and 3 were similar to those of the nontransplanted healthy animals. In conclusion, FK778 monotherapy after a consistent induction period with tacrolimus combined immunosuppression is able to extend survival and preserve optimal absorptive capacity of the small bowel allograft in our pig model. The association of tacrolimus and FK778 from day 1, compared to the delayed administration of FK778 from day 7, results in a significant reduction of infections and postoperative complications.

The new malononitrilamide immunosuppressant FK778 prolongs corneal allograft survival in the rat keratoplasty model

PURPOSE

Aim of this study was to prove the efficacy and safety of the new malononitrilamide immunosuppressive FK778 in prolonging clear graft survival following allogeneic orthotopic keratoplasty in rats.

METHODS

Sixty-seven penetrating keratoplasties were performed using Fisher and Lewis rats as donors and recipients, respectively: group 1 (n=11), allogeneic control without therapy; group 2 (n=12), syngeneic control; group 3 (n=11), mycophenolate mofetil (MMF) 40 mg/kg bodyweight; group 4 (n=12), FK778 5 mg/kg bodyweight; group 5 (n=12), FK778 10 mg/kg bodyweight; and group 6 (n=9), FK778 20 mg/kg bodyweight. Four animals in each group were killed for immunohistological evaluation on day 14. Therapy was administered orally for 18 days. The grafts were evaluated every three days by means of a scoring system including opacity, oedema, and vascularization. Time to rejection was analysed with the Kaplan-Meier survival analysis and compared with the log-rank test. The densities of infiltrating immune cells were compared statistically using the non-parametric Mann-Whitney test.

RESULTS

Mean rejection-free graft survival was 11.4 days in group 1 (allogeneic control), 100 days (total follow-up time) in group 2 (syngeneic control), 24.0 days in group 3 (MMF 40 mg/kg), 15.7 days in group 4 (FK778 5 mg/kg), 19.1 days in group 5 (FK778 10 mg/kg), and 25.4 days in group 6 (FK778 20 mg/kg) (P<0.005).

CONCLUSIONS

Systemic immunosuppression with FK778 prolongs graft survival in the rat keratoplasty model. FK778's efficacy is comparable with that of MMF in preventing immunologic graft rejection.

The Effect of FK778 on the Progression of Chronic Allograft Nephropathy in a Rat Model

BACKGROUND

Chronic allograft nephropathy (CAN) still belongs to the leading causes of graft loss over the long term. The leflunomide derivative FK778 is a novel immunosuppressant with improved pharmacokinetic properties that effectively prolonged graft survival in several transplantation models. In the present study, we investigated the effects of FK778 at different phases after transplantation on the progression of CAN.

METHODS

Fisher 344 kidneys were orthotopically transplanted into Lewis recipients. Recipients were treated with FK778 (5 mg/kg/day) over different time periods (early: days 0-10 only, continuous: day 0 to week 24, or late: weeks 16-24 only posttransplantation). Proteinuria was measured every 4 weeks, whereas grafts were harvested at 24 weeks posttransplantation for morphological and immunohistochemical analysis as well as transforming growth factor-beta and platelet derived growth factor-B chain expression.

RESULTS

Continuous treatment with FK778 ameliorated the progression of CAN, whereas late treatment reduced proteinuria and resulted in a similar grade of CAN as compared to animals with continuous treatment. In contrast, FK778 given only during the early phase after transplantation had no effect on the progression of CAN as compared to controls.

CONCLUSION

In summary, FK778 is a potent immunosuppressive drug that can delay the progression of CAN, even when given at later stages after transplantation.

Is the Malononitrilamide FK778 Better for the Prevention of Acute or Chronic Rejection?

OBJECTIVE

The aim of this study was to assess the efficacy of FK778 to prevent acute and chronic allograft rejection compared with other immunosuppressive agents.

MATERIALS AND METHODS

Heterotopic Brown-Norway (BN)-to-Lewis rat cardiac transplantations and heterotopic BN-to-Lewis tracheal transplantations were performed to study acute heart rejection and the development of chronic obliterative airway disease (OAD), respectively. Recipients were treated with FK778, tacrolimus, MMF, or sirolimus for 10 days (acute rejection study) or 28 days (chronic OAD study) at varying doses.

RESULTS

In untreated recipients, cardiac allograft survival was 6.2 +/- 0.4 days. FK778 (20 mg/kg), tacrolimus (2 or 8 mg/kg), mycophenolate mofetil (MMF; 40 mg/kg), or sirolimus (0.5 or 2 mg/kg) significantly prolonged graft survival to 17.0 +/- 2.8, 18.5 +/- 2.7, 25.0 +/- 2.5, 20.7 +/- 3.8, 14.5 +/- 2.2, and 23.2 +/- 1.5 days, respectively (P < .05). Tracheal grafts in untreated recipients showed intense infiltration and complete luminal obliteration by day 28. FK778 (20 mg/kg), tacrolimus (1 or 4 mg/kg), MMF (10 or 40 mg/kg), or sirolimus (0.5 or 2 mg/kg) significantly inhibited tracheal luminal obliteration (19.5% +/- 16.4%, 44.2% +/- 33.6%, 12.3% +/- 3.3%, 61.7% +/- 18.6%, 18.3% +/- 11.3%, 55.0% +/- 30.9%, and 8.5% +/- 3.5% (P < .05). All 4 high-dose groups showed similar efficacy.

CONCLUSIONS

When used in therapeutic doses, tacrolimus and sirolimus were more effective than FK778 to prolong cardiac allograft survival. However, with its antiproliferative effects on smooth muscle cells, its good tolerability, and its blockade of cytomegalovirus replication, FK778 proved effective to prevent chronic OAD development. Thus, FK778 may acquire an important role in maintenance therapy for the prevention of long-term fibroproliferative complications.

The Vitamin D analogue TX 527 blocks NF-kappaB activation in peripheral blood mononuclear cells of patients with Crohn's disease

Crohn's disease (CD) is an inflammatory disease characterized by the activation of the immune system in the gut. Since tumor necrosis factor (TNF-alpha) plays an important role in the initiation and perpetuation of intestinal inflammation in CD, we investigated whether TX 527 [19-nor-14,20-bisepi-23-yne-1,25(OH)(2)D(3)], a Vitamin D analogue, could affect peripheral blood mononuclear cells (PBMC) proliferation and exert an immunosuppressive effect on TNF-alpha production in CD patients, and whether this immunosuppressive action could be mediated by NF-kappaB down-regulation. TX 527 significantly decreased cell proliferation and TNF-alpha levels. On activation, NF-kappaB, rapidly released from its cytoplasmatic inhibitor (IKB-alpha), transmigrates into the nucleus and binds to DNA response elements in gene promoter regions. The activation of NF-kappaB, stimulated by TNF-alpha, and its nuclear translocation together with the degradation of IKB-alpha were blocked by TX 527. At the same time, NF-kappaB protein levels present in cytoplasmic extracts decreased in the presence of TNF-alpha and increased when PBMC were incubated with TX 527. The results of our studies indicate that TX 527 inhibits TNF-alpha mediated effects on PBMC and the activation of NF-kappaB and that its action is mediated by Vitamin D receptor (VDR), which is activated when the cells are stimulated with TX 527.

FK778 in Experimental Xenotransplantation: A Detailed Analysis of Drug Efficacy

BACKGROUND

This study examines the efficacy of FK778 regimens for prevention of different phases of xenograft rejection.

METHODS

Antibody and complement tissue depositions were measured by immunofluorescence in a discordant ex vivo rat-to-human heart perfusion model of hyperacute rejection with immunosuppressant-enriched human blood. The concordant hamster-to-rat aortic xenotransplantation model was used to assess host cellular (lymphocyte activation, mixed lymphocyte reaction [MLR]) and humoral responsiveness (xenoantibody production) as well as histologic xenograft rejection. Recipients were treated for 14 days with FK778, tacrolimus, sirolimus or combination regimens at varying doses.

RESULTS

Antibody binding during hyperacute rejection was unaffected by the immunosuppressive treatment, but complement deposition was reduced in the following order: tacrolimus > FK778 approximately sirolimus. FK778 most effectively reduced complement factor 5 in vitro. In untreated rats with hamster aortic xenografts, a large infiltrative response was observed within the grafts with extensive myocyte necrosis. Tacrolimus > FK778 approximately sirolimus dose-dependently diminished xenograft infiltration and in the same order reduced vessel-wall myocyte necrosis. Tacrolimus approximately FK778 > sirolimus reduced in vivo lymphocyte CD25 expression and tacrolimus > FK778 approximately sirolimus diminished MLR. Xenoreactive IgM and IgG antibody production levels were vigorously upregulated a few days after transplantation, but were significantly reduced by tacrolimus > FK778 approximately sirolimus. Combination regimens revealed no significant benefit when compared with the corresponding monotherapy groups.

CONCLUSIONS

FK778 mildly interfered with hyperacute rejection and markedly suppressed acute humoral and cellular aortic xenograft rejection. However, T-cell-dependent host responses were most potently suppressed by tacrolimus, and the overall efficacy of FK778 was similar to that of sirolimus.

The Effect of Leflunomide Analogue FK778 on Development of Chronic Rat Renal Allograft Rejection and Transforming Growth Factor-BETA Expression

BACKGROUND

Chronic allograft nephropathy (CAN) remains the primary reason for late allograft loss in kidney transplantation. Transforming growth factor beta (TGF-beta) is a major mitogen mediating mesenchymal cell proliferation and epithelial to mesenchymal cell transition in CAN. FK778, an analogue of an active metabolite of leflunomide, is a promising immunosuppressive drug that inhibits de novo pyrimidine biosynthesis. Herein we investigated the effect of FK778 on development of chronic rejection and TGF-beta expression in combination with calcineurin inhibitors cyclosporine (CsA) and tacrolimus (Tac).

METHODS

Kidney transplantations were performed from DA to WF rats and syngeneic control transplantations between DA rats. Allografts were immunosupressed alone with CsA (1.5 mg/kg/d subcutaneously) or Tac (1.5 mg/kg/d orally) or with combinations of FK778 (10 mg/kg/d orally) and CsA or Tac. No immunosuppression was given to syngeneic grafts. Grafts were harvested 90 days after transplantation for histology and immunohistochemistry (TGF-beta, TGF-betaR1). The chronic changes in allografts were scored according to the Chronic Allograft Damage Index (CADI).

RESULTS

No histological signs of chronic rejection were seen in syngeneic grafts. According to CADI, moderate chronic changes were seen in grafts treated only with CsA or Tac. In both groups the changes typically associated with CAN were significantly ameliorated with FK778. CsA-treated grafts showed intense posttransplant expression of TGF-beta and TGF-betaR1 after 90 days. In grafts treated with Tac monotherapy this expression was substantially lower. FK778 markedly reduced the expression of TGF-beta and TGF-betaR1 when combined with calcineurin inhibitors and lesser expression was demonstrated with the combination of FK778 and Tac.

CONCLUSIONS

Our results demonstrated that FK778 is a potent immunosuppressive drug having synergistic effects with calcineurin inhibitors. When combined with CsA or Tac, it decreased posttransplant TGF-beta ligand and receptor expression. Our data also showed that FK778 prevented chronic changes typically associated with CAN. Taken together our results suggested that FK778 could be a promising therapy for CAN in clinical kidney transplantation.

Inhibition of Restenosis Development after Mechanical Injury: A New Field of Application for Malononitrilamides?

OBJECTIVE

To investigate the efficacy of the malononitrilamide FK778 to prevent vascular smooth muscle cell (SMC) migration/proliferation, and vascular fibrosis, the key events in restenosis development using in vivo and in vitro studies.

BACKGROUND

Since the high rate of restenosis after percutaneous transluminal coronary angioplasty limited its long-term success, the implementation of locally delivered antiproliferative/immunosuppressive agents became advantageous.

METHODS

Rats underwent balloon denudation of the abdominal aorta and received sirolimus, tacrolimus, or FK778 for 28 days in varying doses. Aortas were harvested for histologic evaluation, profibrotic gene expression, and organ chamber studies. Antifibrotic, antiproliferative and antimigratory effects of the immunosuppressants were further evaluated in vitro.

RESULTS

Histology of untreated animals revealed marked intimal hyperplasia with moderate luminal obliteration. Neointima formation was dose-dependently attenuated by all three agents with FK778 and sirolimus being most efficacious. Organ chamber relaxation studies showed a leftward shift of the nitroglycerin and the acetylcholine dose-responses in all treatment groups, indicating diminished endothelial dysfunction. In vivo, only FK778 treatment revealed a significant downregulation of the TGF-beta/vasorin system which could be explained by upregulation of the TGF-beta-inhibitory mediator SMAD7. In vitro, FK778 showed most potent antiproliferative and antimigratory effects on SMC compared with sirolimus and tacrolimus. Only the antiproliferative effect of FK778 was due to pyrimidine synthesis blockade and could be reversed by uridine supplementation.

CONCLUSIONS

The malononitrilamide FK778 proved highly efficacious against restenosis development by targeting two major components of intimal hyperplasia: SMC proliferation/migration and vascular fibrosis. Thus, the introduction of malononitrilamide-loaded stents may be a promising effort for future strategies.

Role of hydrogen sulfide in acute pancreatitis and associated lung injury

Hydrogen sulfide (H2S) is a naturally occurring gas with potent vasodilator activity. Cystathionine-gamma-lyase (CSE) and cystathionine-beta-synthase (CBS) utilize L-cysteine as substrate to form H2S. Of these two enzymes, cystathionine-gamma-lyase (CSE) is believed to be the key enzyme that forms H2S in the cardiovascular system. Whilst H2S has been reported to relax precontracted rat arteries in vitro and to lower blood pressure in the rat, its effect in an inflammatory condition such as acute pancreatitis has not previously been reported. In this paper, we report the presence of H2S synthesizing enzyme activity and CSE (as determined by mRNA signal) in the pancreas. Also, prophylactic, as well as therapeutic, treatment with the CSE inhibitor, DL-propargylglycine (PAG), significantly reduced the severity of caerulein-induced pancreatitis and associated lung injury, as determined by 1) hyperamylasemia [plasma amylase (U/L) (control, 1204+/-59); prophylactic treatment: placebo, 10635+/-305; PAG, 7904+/-495; therapeutic treatment: placebo, 10427+/-470; PAG, 7811+/-428; P<0.05 PAG c.f. placebo; n=24 animals in each group]; 2) neutrophil sequestration in the pancreas [pancreatic myeloperoxidase oxidase (MPO) activity (fold increase over control) (prophylactic treatment: placebo, 5.78+/-0.63; PAG, 2.97+/-0.39; therapeutic treatment: placebo, 5.48+/-0.52; PAG, 3.03+/-0.47; P<0.05 PAG c.f. placebo; n=24 animals in each group)]; 3) pancreatic acinar cell injury/necrosis; 4) lung MPO activity (fold increase over control) [prophylactic treatment: placebo, 1.99+/-0.16; PAG, 1.34+/-0.14; therapeutic treatment: placebo, 2.03+/-0.12; PAG, 1.41+/-0.97; P<0.05 PAG c.f. placebo; n=24 animals in each group]; and 5) histological evidence of lung injury. These effects of CSE blockade suggest an important proinflammatory role of H2S in regulating the severity of pancreatitis and associated lung injury and raise the possibility that H2S may exert similar activity in other forms of inflammation.

Do antioxidant strategies work against aging and age-associated disorders? Propargylamines: a possible antioxidant strategy

The free radical theory of aging was initially proposed by Harman half a century ago primarily to explain biological aging processes. Although administration of so-called antioxidant chemicals, which have been tested in the past for several decades, turned out to be mostly ineffective in prolonging the life spans of animals, the same theory of age-associated diseases appears to be increasingly supported in the last two decades. Despite these difficulties, the success in extending life span of 4 different animal species (mice, rats, hamsters, and dogs) with (-)deprenyl (including a study of our group) indicates that there might exist another type of antioxidant strategy in addition to a simple administration of antioxidant chemicals. (-)Deprenyl has also been shown to increase superoxide dismutase (SOD) and catalase (CAT) activities selectively in brain dopaminergic tissues. Interestingly, we have recently shown that another propargylamine, rasagiline not only increases antioxidant enzyme activities (CAT and SOD) in brain dopaminergic regions as (-)deprenyl does, but also increases CAT and SOD activities in extrabrain catecholaminergic systems such as the heart and kidneys as well. These recent observations coupled with previous observations on the life span of animals with (-)deprenyl suggest that pharmacological modulation of endogenous antioxidant enzyme activities could be one potential antioxidant strategy against aging and age-associated disorders. If the causal relationship between the two effects of (-)deprenyl exists as we hypothesized, we might be able to advance the elucidation of mechanism(s) of aging based on the free radical theory of aging.

Effect of petroleum ether extract of Panax ginseng roots on proliferation and cell cycle progression of human renal cell carcinoma cells

Panax ginseng roots have long been used as a medicinal herb in oriental countries. We have investigated anti-proliferative effects of lipid soluble Panax ginseng components on human renal cancer cell lines. Petroleum ether extract of Panax ginseng roots (GX-PE) or its partially purified preparation (7:3 GX) was added to cultures of three human renal cell carcinoma (RCC) cell lines, A498, Caki-1, and CURC II. Proliferation of RCC cells was estimated by a [3H]thymidine incorporation assay and cell cycle distribution was analyzed by flow cytometry. GX-PE, 7:3 GX, panaxydol and panaxynol inhibited proliferation of all three RCC cell lines in a dose dependent manner in vitro with an order of potency, 7:3 GX > panaxydol > panaxynol = GX-PE. Additive effect of interleukin 4 was also demonstrated, most prominently in Caki-1 which responded poorly to GX-PE alone. Analysis of cell cycle in CURC II and Caki-1 treated with GX-PE demonstrated increase in G1 phase population and corresponding decrease in S phase population. The present study demonstrated that proliferation of human RCC cell lines were inhibited by lipid soluble components of Panax ginseng roots by blocking cell cycle progression at G1 to S phase transition.

Santolindiacetylene, a polyacetylene derivative isolated from the essential oil of Santolina canescens

The yield, composition, and some pharmacological activities (hepatoprotective and antioxidant) of the essential oil of Santolina canescens aerial parts have been investigated. The essential oil qualitative data were determined by gc and gc-ms. The main component, santolindiacetylene [1], was isolated and characterized by spectral methods, and the structure assigned as 1-(2'-naphthyl)hexa-2,4-diyne. The protective activities of the essential oil and its main component [1] were evaluated against carbon tetrachloride-induced hepatotoxicity in a rat model. In both cases a significant hepatoprotective effect was observed, as evident from the strong decrease of elevated GPT serum levels caused by carbon tetrachloride-induced hepatic damage.

The pharmacokinetic behaviour of hypoxoside taken orally by patients with lung cancer in a phase I trial

OBJECTIVE

To study the pharmacokinetic behaviour of hypoxoside taken orally by 24 patients with lung cancer.

DESIGN

Randomised open study with three single doses of 1,600, 2,400 and 3,200 mg standardised Hypoxis plant extract (200 mg capsules) and a multiple-dose study on the first 6 patients taking 4 capsules 3 times daily for 11 days.

PARTICIPANTS AND SETTING

Patients with histologically proven squamous, large-cell or adenocarcinoma were hospitalised at the Radiation Oncology Ward, Karl Bremer Hospital, Bellville, W. Cape.

METHODS

Blood was drawn at regular intervals up to 75 hours after single doses and the concentrations of metabolites of the aglucone of hypoxoside, rooperol, were measured with a high-performance liquid chromatography method. For the multiple-dose study blood was drawn before the first dose each day. Concentration-time relationships were analysed according to a conventional single open-compartment model and also by using the NONMEM digital computer programme.

RESULTS

Neither hypoxoside nor rooperol appear in circulation. This is due to complete phase II biotransformation to diglucuronide, disulphate and mixed glucuronide-sulphate metabolites, of which the latter is the major component. Considerable interpatient variation in concentration-time relationships was found in the single-dose studies. It was due to an active enterohepatic recirculation in some patients and a distinct lag phase in others together with zero-order rate of formation of rooperol in the colon. Computer modelling indicated a single open-compartment model in which the mass of the patient did not influence volume of distribution and clearance because formation of the metabolites is dependent on the metabolising capacity of the patient. However, the elimination of the metabolites follows first-order kinetics with half-lives ranging from 50 hours for the major metabolite to 20 hours for the two minor metabolites. Multiple-dose studies also showed large interpatient variation.

CONCLUSION

In order to reach metabolite levels near 100 micrograms/ml, which have been shown to be tumouricidal after enzymatic deconjugation to rooperol, maintenance doses need to be individualised for each patient. For most patients, however, a daily dose of 2,400 mg was sufficient.

Effects of tebufelone (NE-11740), a new anti-inflammatory drug, on arachidonic acid metabolism

Tebufelone is a novel nonsteroidal anti-inflammatory drug (NSAID), of the di-tert-butylphenol (DTBP) class, which displays potent anti-inflammatory, analgesic and anti-pyretic properties in a variety of animal models. In this report, the effects of Tebufelone on arachidonic acid (AA) metabolism are reviewed. Tebufelone potently inhibits the formation of prostaglandins (PGE2) a key mediator of pain and inflammation, in isolated enzyme preparations (IC50 = 1.5 microM, KI = 0.35 microM), two in vitro cellular systems: rat peritoneal macrophages (IC50 = 0.02 microM) and human whole blood (IC50 = 0.08 microM), and ex vivo in man. In addition to PGE2 inhibition, which is common to all NSAIDs, higher concentrations of Tebufelone block the in vitro formation of products of the lipoxygenase pathway [leukotrienes (LTB4)] in rat macrophages (IC50 = 20 microM) and human whole blood (IC50 = 22 microM). Substrate incorporation studies (14C-AA) indicate that Tebufelone reversibly inhibits cyclooxygenase (CO) and 5-lipoxygenase (5-LO) enzymes rather than regulating the release of AA. Tebufelone was shown to be a more potent CO inhibitor than indomethacin and a less potent 5-LO inhibitor than RG-5901. Comparisons to structurally related compounds under development (E-5110, Esai; KME-4, Kanagafuchi), found Tebufelone to be the most potent CO inhibitor in vitro. All three DTBP compounds were equipotent 5-LO inhibitors. It is likely that Tebufelone's inhibitory effects on AA metabolism are, in part, responsible for its in vivo efficacy and enhanced safety profile.

Inhibition of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone mouse lung tumorigenesis by arylalkynes, mechanism-based inactivators of cytochrome P450

Arylalkynes such as 4-phenyl-1-butyne (PBY), 5-phenyl-1-pentyne (PPY) and 2-ethynylnaphthalene (2-EN) are suicide inhibitors of cytochrome P450 enzymes. Arylalkyl isothiocyanates such as 6-phenylhexyl isothiocyanate (PHITC) are structurally related to arylalkynes and are known to inhibit the cytochrome P450 mediated metabolic activation and tumorigenicity of a tobacco-specific lung carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In this study, we compared the ability of PBY, PPY, 2-EN and PHITC to inhibit A/J mouse lung tumorigenesis by NNK. Groups of 20 female mice were gavaged with 5 mumol of arylalkyne or PHITC in corn oil. Two hours later they were given a single i.p. injection of 10 mumol NNK. The mice were killed 16 weeks later. PPY and PHITC were both potent inhibitors of tumorigenesis by NNK, reducing lung tumor multiplicity from 8.35 tumors per mouse to 0.40 and 0.35 respectively. PBY and 2-EN also significantly inhibited tumor multiplicity. The results of this study demonstrate that arylalkynes and PHITC are potent inhibitors of NNK induced lung tumorigenesis in A/J mice, consistent with the hypothesis that inhibition of specific cytochrome P450 enzymes is involved in inhibition of tumorigenesis.

Analogues of oxybutynin. Synthesis and antimuscarinic and bladder activity of some substituted 7-amino-1-hydroxy-5-heptyn-2-ones and related compounds

Oxybutynin chloride [4-(diethylamino)-2-butynyl alpha-cyclohexyl-alpha-hydroxybenzeneacetate hydrochloride, Ditropan] is widely used for the relief of symptoms in neurogenic bladder. This is a result of its combined anticholinergic, antispasmodic, and local anesthetic activities. In a study directed toward development of agents possessing the beneficial properties of oxybutynin, but having a longer duration of action, a series of metabolically more stable keto analogues of the parent ester, i.e. substituted 7-amino-1-hydroxy-5-heptyn-2-ones along with some analogues and derivatives, was prepared and evaluated for in vitro and in vivo antimuscarinic action in guinea pig preparations. Several members of the series were potent antimuscarinics having a longer duration of activity than that of oxybutynin in a guinea pig cystometrogram model. On the basis of its in vitro and in vivo antimuscarinic activity, coupled with a 5-fold greater duration of action than that of oxybutynin, 1-cyclobutyl-7-(dimethylamino)-1-hydroxy-1-phenyl-5-heptyn-2-one (14b) was selected for clinical evaluation.

A new clinical bioassay for antipyresis

Three studies that describe antipyretic bioassay are detailed. Reference Standard Endotoxin (RSE) was used to induce fever in healthy male volunteers under randomized, single-dose, double-blind, parallel, and standard drug-control conditions. Thirty minutes before administering RSE, the subjects were medicated with test drug, and oral temperatures were recorded every 15 minutes for 6 to 8 hours. Two NSAIDs and a centrally acting analgesic were evaluated. Both doses of a propionic derivative, three high doses of tebufelone (a new NSAID), as well as the high dose of flupirtine effectively obtunded the fever response to RSE. Adverse reactions consisting of flu-like symptoms such as myalgia, headache, and chills were also significantly reduced with the standard as well as test drugs. The authors conclude that the RSE model is a quick, safe, and reliable method to evaluate antipyresis and to predict other pharmacologic effects of these types of drugs, such as analgesia.

[Effect of hypoxia and hyperthermia on the processes of lipid peroxidation in the rat liver against a background of the action of gutimine and unsaturated amines]

Following the action of extraordinary stimulants (hypoxic hypoxia, hypoxia+hyperoxia, hypodynamia+hyperthermy) animals demonstrate accumulation of malonic dialdehyde with a simultaneous fall of antiradical activity of the liver tissue. A preliminary introduction to rats of acetylene amines--1,4 bis (3-morpholinopropynyl) benzol 3,4,5-(morpholinopropynyl)-1-methylpyrazol and also of tocopherol antioxidant and gutumine antihypoxant averts activation of the lipids peroxidation processes. The inhibition of peroxidation with the studied agents is attended by stabilization of lyzosomal and mitochondrial membranes. Unsaturated amines prevent destruction of the organelles membranes provoked by the UV-irradiation and incubation at 37 degrees C (pH--4.7).