Soo-Hwan Yeo

Antifungal effect of amentoflavone derived from Selaginella tamariscina

Amentoflavone is a plant biflavonoid that was isolated from an ethyl acetate extract of the whole plant ofSelaginella tamariscina (Beauv.) spring. 1D and 2D NMR spectroscopy including DEPT, HMQC, and HMBC were used to determine its structure. Amentoflavone exhibited potent antifungal activity against several pathogenic fungal strains but had a very low hemolytic effect on human erythrocytes. In particular, amentoflavone induced the accumulation of intracellular trehalose onC. albicans as a stress response to the drug, and disrupted the dimorphic transition that forms pseudo-hyphae during pathogenesis. In conclusion, amentoflavone has great potential to be a lead compound for the development of antifungal agents.

Cloning and characterization of a gene encoding the γ-butyrolactone autoregulator receptor from Streptomyces clavuligerus

With primers designed for the conserved region of the γ-butyrolactone autoregulator receptor proteins from Streptomyces species, PCR using the Streptomyces clavuligerus genome DNA as a template gave a clear band of 100xa0bp, the sequence of which revealed high similarity to the expected region of a receptor gene. By Southern blot and colony hybridization with the 100-bp insert as a probe, plasmid pSCA, harboring a 4.2xa0kb-SalI fragment, was obtained. Sequence analysis on the insert revealed a 702-bp ORF encoding a protein with a moderate similarity (identity, 33–43%; similarity, 51–62%) to known γ-butyrolactone autoregulator receptor proteins from Streptomyces sp. The ORF was named scaR (S. clavuligerus autoregulator receptor). The scaR/pET-3d plasmid was constructed for overexpression of the recombinant ScaR protein (rScaR) in Escherichia coli, and the rScaR protein was purified to homogeneity by DEAE-ion-exchange HPLC. The molecular mass of the purified rScaR protein was determined to be 27xa0kDa as determined by SDS-PAGE, and 54xa0kDa by gel filtration HPLC under nondenatured conditions at a low protein concentration, indicating that the majority of the native ScaR is present in the form of a dimer, although rScaR tended to aggregate into a higher molecular form of 230xa0kDa at a high protein concentration. A binding assay with tritium-labeled autoregulators indicated that IM-2 type compounds with a long C2 side chain were the most effective ligands for rScaR, demonstrating for the first time that the β-lactam producer S. clavuligerus contains a gene for the γ-butyrolactone autoregulator receptor.

Long-term Clinical Outcomes of First and Second Kidney Transplantation in Patients With Biopsy-Proven IgA Nephropathy

INTRODUCTIONnThe recurrence of IgA nephropathy (IgAN) after kidney transplantation (KT) has an effect on graft survival, but there are few reports about long-term clinical outcomes of KT with recurrent IgAN. This study shows the long-term clinical outcomes of KT in patients with IgAN.nnnMETHODSnAll recipients who had biopsy-proven IgAN were followed from February 1990 to February 2016. We analyzed overall graft and patient survival rates, incidence of recurrent IgAN, factors affecting graft survival, and IgAN recurrence.nnnRESULTSnThere were 88 patients with first KT. The mean follow-up duration was 82.5 months. Twenty patients went through graft loss and 1 patient died due to sepsis. IgAN recurred in 15 patients, and 11 patients experienced graft failure. Among the patients who had failed graft after first KT, 7 patients underwent retransplantation. The graft survival period, presence of rejection, and proteinuria were the relevant risk factors for recurrence of IgAN. In the first KT patients, presence of rejection and 1-year serum creatinine were the significant risk factors for graft loss. But recurrence of IgAN was not a relevant risk factor. Overall graft survival rates at 5 and 10 years were 93.8% and 73.1% in the first transplantation group and 100% and 100% in the retransplantation group, respectively.nnnCONCLUSIONnAlthough IgAN recurrence was a significant risk factor for graft failure, the patient who underwent retransplantation showed favorable results. Retransplantation should be considered in patients who lost their first graft after recurrence of IgAN.

Long-term Clinical Outcomes of Kidney Re-transplantation

BACKGROUNDnKidney re-transplantation is commonly considered to have a higher immunological risk than first kidney transplantation. Because of the organ shortage and increasing waiting lists, long-term outcomes of kidney re-transplantation are being studied. However, reports of re-transplantation outcomes are not common. We have reported our 30 years of experience with second kidney transplantations.nnnMETHODSnOf 1210 kidney transplantations between November 1982 and August 2016 performed in our hospital, 105 were second kidney transplantations (2nd KT). Living donor KT was 44; deceased donor KT wasxa061.nnnRESULTSnPatient survival rates at 1, 5, and 10 years were 100%, 97.2%, and 90.7%, and graft survival rates were 97.0%, 94.6%, and 71.5%, respectively. The leading cause of graft failure in the 2nd KT was chronic rejection (60%). In addition, induction immunosuppressant, maintenance immunosuppressant, delayed graft function, and graft survival time at the 1st KT had a significant impact on graft survival time at the 2nd KT.nnnCONCLUSIONSnReasonable results in both patient survival and graft survival rates were found in the 2nd KT. Careful monitoring of immunologic risk is needed.

Clinical Outcomes of Kidney Transplantation in Patients With Biopsy-Proven Glomerulonephritis

BACKGROUNDnThe clinical outcomes after kidney transplantation (KT) according to the types of glomerulonephritis (GN) as the cause of end-stage renal disease (ESRD) are various, but there are not many studies on this.nnnMETHODSnAmong 1,253 patients who had KT between November 1982 and January 2017, 183 recipients with biopsy-proven GN as the primary cause of ESRD were enrolled. We analyzed the incidence of recurrent GN and the factors associated with recurrence and graft and patient survivals.nnnRESULTSnThe types of GN were 95 IgA nephropathy, 47 focal segmental glomerulosclerosis, 14 membranous proliferative GN, 9 membranous GN, 8 lupus nephritis, 6 rapid progressive GN, and 4 Alport syndrome. The mean follow-up duration was 103 ± 81.7 months. Recurrence was reported in 36 patients, of which 20 grafts failed due to recurrence. The age of patients with GN recurrence was significantly younger than that of patients without GN recurrence (Pxa0=xa0.030). The graft failure rate of KT recipients with recurrent GN was significantly higher than that of the recipients without recurrent GN (55.6% vs 18.4%, Pxa0< .001). In multivariate analysis, recurrence of primary GN, the number of HLA mismatches at AB, delayed graft function, and acute rejection were independent risk factors for graft failure.nnnCONCLUSIONnRecurrent GN remains a significant cause of graft loss in KT recipients. Surveillance of GN recurrence in the KT recipients with biopsy-proven GN can reduce allograft dysfunction.

Antifungal Activity of Extract from Xmthitim strumarium L. Against Plant Pathogenous fungi.

Antifungal activity of ether and ethylacetate extract from Xanthium strumarium L. were tested against 11 plant pathogens by agar diffusion method. Antifungal activity of the ether and ethylacetate extract showed strong antifungal activity against plant pathogenous fungi, i.e. Phytophthora capsici, Sclerotinia sclerotiorum and Aspergillus niger. The IC50 of the ether extract against Sclerotinia sclerotiorum was determined 335 ㎍/ml. Antifungal activity of the ether extract from Xanthium strumarium L. showed Rf value=0.87 on TLC plate.