Comparative characterisation of extracellular vesicles from canine and human plasma: a necessary step in biomarker discovery.

Extracellular Vesicles (EV) have become an interesting focus as novel biomarkers of disease and are increasingly reported upon in humans and other species. The Minimal Information for Studies of Extracellular Vesicles 2018 (MISEV2018) guidelines were published to improve rigor and standardisation within the EV field and provide a framework for the reliable isolation and characterisation of EV populations. However, this rigor and standardisation has been challenging in the area of comparative medicine. Herein we present the successful isolation of EVs from human and canine plasma using Size Exclusion Chromatography and characterise these EVs according to best international practice. This study provides evidence for the reliable comparison of human and canine EVs isolated by this approach, and a baseline description of the EVs from healthy dogs to inform future biomarker studies. This work also demonstrates that the MISEV2018 guidelines can be successfully applied to EVs isolated from canine plasma.

Data of pre-clinical and early clinical trials of acriflavine and hydroxy-methyl-ellipticine reviewed, enriched by the experience of their use for 18 months to 6 years in combinations with other HIV1 virostatics.

Two virostatics which we discovered in 1990, acriflavine (ACF) and hydroxy-methyl-ellipticine (HEL) and shown active on HIV1 resistant to AZT have been introduced into combinations of four virostatics selected among ten available: themselves, plus zidovudine, zalcitabine, didanosine, lamivudine, stavudine, saquinavir, ritonavir, indinavir, the combinations were applied in 3-week sequences, differing from each other by drug rotation. Those which contained ACF may have more often a CD34 decrease than those containing neither ACF nor HEL, and they present more often a CD4 increase. No significant difference as far as side effects or beneficial effects could be detected after 18 months to 6 years, between sequences containing ACF or HEL or both, and sequences not containing any one of them.

AIDS therapy with two, three or four agent combinations, applied in short sequences, differing from each other by drug rotation. I. First of two parts: a phase I trial equivalent, concerning five virostatics: AZT, ddI, ddC, acriflavine and an ellipticine analogue.

We have individually treated ten AIDS patients whose CD4 numbers were inferior to 200/mm3, with the five following HIV1 virostatics: a) azido-deoxythymidine (AZT), dideoxyinosine (ddI) and dideoxycytidine (ddC), which affect the same viral target, retrotranscriptase, b) acriflavine (ACF) and methyl-hydroxy-ellipticine (MHE) which we have discovered to be strong virostatics in vivo, in mice, against Friend's virus, and in man, against AZT resistant HIV1. We have shown that their combinations with AZT, hitting three viral targets, reduces in mice, the blood Friend's virus load below detectable level. Due to the short doubling time of HIV1, AIDS therapy must be continuous, and to allow the best tolerance, the five virostatic combinations were applied in short, three-week sequences, each differing as much as possible from the former and from the following one, due to drug rotation [1]. Among the ten patients, a) three received the two-drug combinations for 15 to 30 months, followed by the three-drug combinations, b) three received the three-drug combinations from the beginning, c) four received the four-drug combinations also from the beginning, two having less than 10 CD4/mm3 at initiation of treatment, and two having more than 100. The tolerance was remarkable: the only side-effect being macrocytosis. The application of the two-drug combination sequences maintained stable CD4 levels in two subjects whose viral load (the evaluation of which had became available) was, at the end of this period, of 4,486 and 39,238 RNA copies. The third subject who had received, an intensive UV irradiation for a psoriasis, presented an irreversible decrease in his CD4 count and a high viral load (1,352,495 RNA copies/mL) at the end of the two-drug period. Fifteen to 25 months after the shift to the three-drug combinations, the viral load decreased, from 39,328 to 13,291 in one of the non-UV irradiated subjects, and from 1,352,495 to 314,387 in the irradiated one. No subject had an increase in CD4 number. In the three patients having initially received the three-drug combinations, a very strong decrease of viral load was registered after periods of observation varying from 77 to 40 months, while the CD4 counts increased moderately in two subjects, and noticeably in the third (from 126 to 266). Out of the four subjects initially treated with four-drug combinations, the two with less than 10 CD4/mm3 had a moderate decrease in viral load in about three months, and the CD4 increased from 9 to 34/mm3 in one. But the two subjects, because of opportunistic infections and psychological reasons, abandoned their treatments. In the two subjects who had more than 100 CD4/mm2 at initiation of the four-drug combination treatment, the viral load decreased to undetectable levels after four months: but their CD4 counts, after some oscillations, had very moderately increased at the end of the observation period (respectively, from 200 to 222, and from 129 to 134). In practice, these results suggest the interest of conducting phase II or III studies of AIDS treatment protocols, starting with the four-drug combination model, and attempting to maintain the effect with the three-drug combination one. As for theoretical considerations, one must underline the contrast between the remarkable reduction of the viral load and the usually moderate increase of the CD4 counts. The study but not the trial has been interrupted, due to the unavailability of three antiproteases, saquinavir, ritonavir and indinavir, which are now introduced in the same type of combinations, one by one, in replacement of one of the studied agents as shown in figure 1. The effect of increasing the total number of virostatics from five to eight will be published in the second part of this article series.

A phase I trial of trans-1-diaminocyclohexane oxalato-platinum (l-OHP).

Oxalato-platinum in a new platinum derivative which was found to be active in experimental tumors and devoid of nephrotoxicity. A phase I study was conducted in cancer patients according to a new design following the recommendations of our Institution's ethical committee to avoid the major drawback of classical phase I studies in which many patients receive the experimental drug at doses far under the potentially active dose extrapolated from experimental studies. The potentially active dose of l-OHP was determined from the Maximally Efficient Dose Range (MEDR) to be between 45 mg/m2 (subcurative dose) and 67 mg/m2 (subtoxic dose). The patients in this study received with increasing intervals 1/100, 1/10, 1/5, 1/3, 1/2, 2/3, 3/4, 1, of the low dose of the MEDR, this dose being reached after 90 to 120 days on study. 23 evaluable patients have entered the trial of which 19 reached the low dose of MEDR (45 mg/m2). Gastro-intestinal toxicity, nausea and vomiting, similar to those with CDDP occurred in all patients at or above the dose of 30 mg/m2. Renal toxicity was monitored with creatinine level and did not occur in any patient at any dose nor did significant hematologic toxicity occur. Thus nausea and vomiting appear to be the limiting toxicity of the drug. Responses were observed in this phase I study in lung cancer (1), breast cancer (1), melanoma (1) and perhaps hepatoma (major decrease in alpha FP levels) (1). The proposed starting dose for phase II studies is 45 mg/m2 but we plan to continue dose escalation during the phase II according to the design of Jones and Holland. This new study design allows each patient entering a phase I study to be treated with a potentially active dose of the drug studied.