Short-term decreased post transplant lymphoproliferative disorder risk after kidney transplantation using two novel regimens.

BACKGROUND: Belatacept is employed alongside calcineurin inhibitor (CNI) therapy to prevent graft rejection in kidney transplant patients who are Epstein-Barr virus (EBV) seropositive. Preliminary data suggested that rates of post-transplant lymphoproliferative disorder (PTLD) were higher in individuals treated with belatacept compared to CNI therapy alone. METHODS: The records of 354 adults who underwent kidney only transplantation from January 2015 through September 2021 at one medical center were evaluated. Patients underwent treatment with either low-doses of mycophenolate, tacrolimus and sirolimus (B0, n = 235) or low-doses of mycophenolate, tacrolimus and belatacept (B1, n = 119). All recipients underwent induction with antithymocyte globulin and a rapid glucocorticosteroid taper. Relevant donor and recipient information were analyzed and endpoints of PTLD were assessed. RESULTS: There were no cases of PTLD in either cohort within the study period. Recipients in the belatacept cohort experienced lower estimated glomerular filtration rates at 12 months (B0: 67.48 vs. B1: 59.10, p = 0.0014). Graft failure at 12 (B0: 1.28% vs. B1: 0.84%, p = 1.0) and 24 months (B0:2.55% vs. B1: 0.84%, p = 0.431) were similar. There was no difference in rejection rates at 12 (B0: 1.27% vs. B1: 2.52%, p = 0.408) or 24 months (B0: 2.12% vs. B1: 2.52%, p = 1.000). Both groups had similar rates of malignancy, mortality and CMV/BK viremia. CONCLUSION: Non-belatacept (MMF, tacrolimus and sirolimus) and belatacept-based (MMF, tacrolimus and belatacept) regimens do not appear to pose any increased risk of early onset PTLD. Both cohorts benefited from low rates of rejection, malignancy, mortality and graft failure. Recipients will continue to be monitored as PTLD can manifest as a long-term complication.

2,4-Diamino-6,7-dimethoxyquinazolines. 4. 2-[4-(substituted oxyethoxy) piperidino] derivatives as alpha 1-adrenoceptor antagonists and antihypertensive agents.

A series of 4-amino-6,7-dimethoxy-2-[4-(substituted oxyethoxy)piperidino] quinazoline derivatives (2) was synthesized and evaluated for alpha-adrenoceptor affinity and antihypertensive activity. Most compounds showed binding affinities within the nanomolar range for alpha 1-receptors, although 25 and 26 showed enhanced potency (Ki, ca. 1.5 X 10(-10) M), equivalent to that of prazosin. Series 2 also displaced [3H]clonidine from alpha 2-adrenoceptors, but at relatively high doses of 10(-6) M, and selectivity for alpha 1 sites still predominated. In a rabbit pulmonary artery preparation, 12, 16, and 25 were potent antagonists of the alpha 1-mediated, postjunctional vasoconstrictor activity of norepinephrine with no effect at the prejunctional alpha 2 sites which modulate transmitter release. Physicochemical measurements gave a pKa of 7.63 +/- 0.10 for 12, and N-1 protonation will be favored (60%) at physiological pH to provide the alpha 1-adrenoceptor pharmacophore, 28. Antihypertensive activity of series 2 was evaluated following oral administration to spontaneously hypertensive rats, and blood pressure was measured after 1 and 6 h. Compounds 12, 13, 16, 23, and 37 displayed moderate efficacy and duration of action in lowering blood pressure, but the plasma half-life (ca. 2 h) of 16 in dogs was not compatible with potential once-daily administration in humans.

2,4-Diamino-6,7-dimethoxyquinazolines. 3. 2-(4-Heterocyclylpiperazin-1-yl) derivatives as alpha 1-adrenoceptor antagonists and antihypertensive agents.

A series of 4-amino-6,7-dimethoxy-2(4-heterocyclylpiperazin-1-yl)quinazolines (3) was prepared and screened for alpha-adrenoceptor affinity and antihypertensive activity. These quinazoline derivatives showed high binding affinity (ca. 10(-10) M) and selectivity (greater than 10,000) for alpha 1-adrenoceptors in vitro, with no relevant activity at alpha 2 sites. Several compounds displayed similar activity to prazosin (Ki = 1.9 X 10(-10) M) while the dimethoxytriazine derivative 30 (Ki = 8 X 10(-11) M) was more potent. Like prazosin (pA2 = 8.37 +/- 0.24), 30 proved to be a potent (pA2 = 8.63 +/- 0.15), competitive antagonist of the alpha 1-mediated vasoconstrictor action of norepinephrine. The high binding affinity of series 3 is most likely due to formation, at physiological pH, of the protonated, alpha 1-adrenoceptor pharmacophore 33, coupled with efficient hydrophobic interactions of the quinazoline 2-substituents. Computer-assisted super-imposition of prazosin and 30 showed little structural correspondence between the furoyl and dimethoxytriazine moieties, and specific interactions of these molecular fragments with the receptor protein appear unlikely. Series 3 was evaluated for antihypertensive activity after oral administration (5 mg/kg) to spontaneously hypertensive rats, and blood pressure was recorded after 1 and 6 h. In vivo performance was markedly dependent on the nature of the distal heterocyclic system and various derivatives demonstrated superior or equivalent profiles to prazosin, with respect to both antihypertensive efficacy and duration of action.

2,4-Diamino-6,7-dimethoxyquinazolines. 2. 2-(4-Carbamoylpiperidino) derivatives as alpha 1-adrenoceptor antagonists and antihypertensive agents.

A series of 4-amino-2-(4-carbamoylpiperidino)-6,7-dimethoxyquinazolines (2) were synthesized and evaluated for alpha-adrenoceptor affinity and antihypertensive activity. These compounds displayed high binding affinity (Ki, 10(-9)-10(-10) M) and selectivity for alpha 1-adrenoceptors in vitro, and 12, 14, 21-26, and 29 showed similar potency to prazosin. Compounds 26 and 28 were also shown to be competitive antagonists of the postjunctional, vasoconstrictor action of norepinephrine with no significant activity at prejunctional alpha 2-sites. The high binding affinity for series 2 is rationalized in terms of enhanced basicity of the quinazoline nucleus (pKa's: 12, 7.38; 26, 7.53; prazosin, 6.8) and hydrophobic interactions of the carbamoyl substituents. Molecular mechanics calculations and computer-assisted superimposition suggest that the quinazoline 2-substituents in prazosin and 2 occupy the alpha 1-adrenoceptor site in different manners. Antihypertensive activity was evaluated after oral administration (5 mg/kg) to spontaneously hypertensive rats, and 11, 15, 21, 22, and 26 displayed sustained prazosin-like efficacy at the 6-h time point. The high alpha 1-adrenoceptor affinity demonstrated by series 2 in vitro suggests that these marked, and prolonged, falls in blood pressure result from selective blockade of the alpha 1-mediated vasoconstrictor effects of norepinephrine.

Synthesis and antibacterial activity of 1-N-(1,3-dihydroxy-2-propyl)kanamycin B (UK-31,214).

1-N-(1,3-Dihydroxy-2-propyl)kanamycin B was prepared and its in vitro activity against aminoglycoside-sensitive and aminoglycoside-resistant organisms was compared with that of kanamycin B and gentamicin. This kanamycin B derivative (code No. UK-31,214) demonstrated potent activity in all of these tests and gave good protection in experimental infections in mice.