Regioselective Hydroxylation of <i>trans</i>-Resveratrol <i>via</i> Inhibition of Tyrosinase from <i>Streptomyces avermitilis</i> MA4680

Secreted tyrosinase from melanin-forming <i>Streptomyces avermitilis</i> MA4680 was involved in both ortho-hydroxylation and further oxidation of <i>trans</i>-resveratrol, leading to the formation of melanin. This finding was confirmed by constructing deletion mutants of <i>melC</i>_<i>2</i> and <i>melD</i>_<i>2</i> encoding extracellular and intracellular tyrosinase, respectively; the <i>melC2</i> deletion mutant did not produce piceatannol as well as melanin, whereas the <i>melD2</i> deletion mutant oxidized resveratrol and synthesized melanin with the same yields, suggesting that MelC2 is responsible for ortho-hydroxylation of resveratrol. Extracellular tyrosinase (MelC2) efficiently converted <i>trans</i>-resveratrol into piceatannol in the presence of either tyrosinase inhibitors or reducing agents such as catechol, NADH, and ascorbic acid. Reducing agents slow down the dioxygenase reaction of tyrosinase. In the presence of catechol, the regio-specific hydroxylation of <i>trans</i>-resveratrol was successfully performed by whole cell biotransformation, and further oxidation of <i>trans</i>-resveratrol was efficiently blocked. The yield of this ortho-hydroxylation of <i>trans</i>-resveratrol was dependent upon inhibitor concentration. Using 1.8 mg of wild-type <i>Streptomyces avermitilis</i> cells, the conversion yield of 100 μM <i>trans</i>-resveratrol to piceatannol was 78% in 3 h in the presence of 1 mM catechol, indicating 14 μM piceatannol h^–1 DCW mg^–1 specific productivity, which was a 14-fold increase in conversion yield compared to that without catechol, which is a remarkably higher reaction rate than that of P450 bioconversion. This method could be generally applied to biocatalysis of various dioxygenases

Delta Neutrophil Index as a Marker for Differential Diagnosis between Acute Graft Pyelonephritis and Acute Graft Rejection

<div><p>Introduction</p><p>The delta neutrophil index (DNI) is the fraction of circulating immature granulocytes, which reflect infectious and/or septic condition. Acute graft pyelonephritis (AGPN) versus acute graft rejection is a frequently encountered diagnostic and therapeutic dilemma in kidney transplant recipients, but little is known about the clinical usefulness of DNI value in the differentiation of the two conditions.</p><p>Material & Methods</p><p>A total of 90 episodes of AGPN or acute graft rejection were evaluated at the Kangdong Sacred Heart Hospital between 2008 and 2014. We performed retrospective analysis of demographic, clinical, and laboratory parameters data. Receiver operating curves (ROC) and multivariate logistic regression were conducted to ascertain the utility of DNI in discriminating between AGPN and acute graft rejection.</p><p>Results</p><p>AGPN group had significantly higher DNI values than acute graft rejection group (2.9% vs. 1.9%, P < 0.001). The area under the ROC curve for DNI value to discriminate between AGPN and acute graft rejection was 0.85 (95% confidence interval [CI]; 0.76–0.92, P < 0.001). A DNI value of 2.7% was selected as the cut-off value for AGPN, and kidney transplant recipients with a DNI value ≥ 2.7% were found to be at a higher risk of infection than those with a DNI < 2.7% (odd ratio [OR] 40.50; 95% CI 8.68–189.08; P < 0.001). In a multivariate logistic regression analysis, DNI was a significant independent factor for predicting AGPN after adjusting age, sex, log WBC count, log neutorphil count, log lymphocyte count, CRP concentration, and procalcitonin concentration (OR 4.32; 95% CI 1.81–10.34, P < 0.001).</p><p>Conclusions</p><p>This study showed that DNI was an effective marker to differentiate between AGPN and acute graft rejection. Thus, these finding suggest that DNI may be a useful marker in the management of these patients.</p></div

Prevalence of acute graft pyelonephritis (AGPN) and acute rejection according to a DNI cutoff of 2.7%.

<p>DNI, delta neutrophil index</p><p>Prevalence of acute graft pyelonephritis (AGPN) and acute rejection according to a DNI cutoff of 2.7%.</p

The impact of DNI on kidney allograft function in acute graft pyelonephritis.

<p>^aIncrease in the serum creatinine concentration of 25% over baseline levels</p><p>^bThe kidney allograft outcomes were evaluated at 1 month after starting antibiotic therapy among episodes with kidney allograft dysfunction</p><p>^c> 25% reduction in serum creatinine</p><p>^d < 25% reduction in serum creatinine</p><p>^eNo reduction in serum creatinine</p><p>The impact of DNI on kidney allograft function in acute graft pyelonephritis.</p

Organism causing acute graft pyelonephritis in kidney transplant recipients.

<p>Organism causing acute graft pyelonephritis in kidney transplant recipients.</p

Clinical and biochemical characteristics in 90 episodes of acute graft pyelonephritis (AGPN) and acute graft rejection.

<p>Values are expresses as mean ± SD or median (range) or number (percentage). BUN, blood urea nitrogen; Cr, creatinine; CRP, C-reactive protein; DNI, delta neutrophil index; Hb, hemoglobin; KT, kidney transplant; PCT, procalcitonin; WBC, white blood cell; m, months</p><p>Clinical and biochemical characteristics in 90 episodes of acute graft pyelonephritis (AGPN) and acute graft rejection.</p

Scattered plots of delta neutrophil index (DNI) values in the three groups: acute graft rejection, AGPN without sepsis, and AGPN with sepsis.

<p>Bar and error bar show the median and range, respectively. *P < 0.001 vs. acute rejection group, **P = 0.031 vs. AGPN group without bacteremia. AGPN, acute graft pyelonephritis.</p

Receiver operating characteristic (ROC) curve values of predictive factors for acute graft pyelonephritis.

<p>AUC, area under the ROC curves; CRP, C-reactive protein; DNI, delta neutrophil index; PCT, procalcitonin; WBC, white blood cell</p><p>Receiver operating characteristic (ROC) curve values of predictive factors for acute graft pyelonephritis.</p

Effects of Angiopoietin-2 on Transplanted Mouse Ovarian Tissue

<div><p>Transplantation of ovarian tissue (OT) is currently the only clinical option to restore fertility with cryopreserved OT. However, follicle loss caused by ischemia and slow revascularization occurs in transplanted OT. To shorten the ischemic period and promote angiogenesis, some angiogenic factors have been used. Angiopoietin-2 (Ang2) is one of the major angiogenic factors and has been reported to promote blood vessels and increase vascular permeability in ischemic and/or hypoxic environment. This study was performed to investigate the effects of Ang2 on follicle integrity and revascularization of transplanted mouse OT. Five-week-old B6D2F1 female mice were divided into a control group and two Ang2 groups, followed by ovary collection and vitrification. After warming, the ovaries were autotransplanted into kidney capsules with/without Ang2 injection (50 or 500 ng/kg), and then the mice were sacrificed at days 2, 7, 21, and 42 after transplantation. A total 2,437 follicles in OT grafts were assessed for follicular density, integrity, and classification by using hematoxylin and eosin staining. Apoptosis and revascularization were evaluated by using TUNEL assay and CD31 immunohistochemistry, respectively. Serum follicle-stimulating hormone (FSH) levels were measured by using enzyme-linked immunosorbent assay. Both Ang2 groups showed remarkable increase in morphologically intact follicle ratio across all grafting durations except D21. The numbers of CD31(+) vessels were significantly increased in both Ang2 groups compared with the control group at all durations, except in the 50 ng Ang2 group at D42. However, the mean numbers of follicles of the grafts, apoptosis ratios, and serum FSH levels showed no significant differences among the groups. Our results show that Ang2 treatment significantly increased the intact follicle ratios and the number of blood vessels of the mouse OT grafts. However, further studies performed with large animal or human OT are necessary before clinical application for fertility preservation in cancer patients, and the reliability of the systemic effects of Ang2 should be verified.</p></div

Anal Human Papillomavirus Infection among HIV-Infected Men in Korea

<div><p>Background</p><p>Little is known about the epidemiology on human papillomavirus (HPV) infection among HIV-infected men in Korea. The objective of this study was to determine the prevalence, genotype distribution and risk factors associated with anal HPV infection among HIV-infected men in Korea.</p><p>Methods</p><p>A single-center cross-sectional study was conducted with HIV-infected men in Korea. Participants completed a detailed sexual behavior risk factor questionnaire. Anal samples were collected for cytology and HPV genotyping. Factors associated with anal HPV infection were assessed using multivariable logistic regression, stratifying by sexual behaviour.</p><p>Results</p><p>A total of 201 HIV-infected men were included in the study: 133 were from men who have sex with men (MSM) and 68 from men who have sex with women (MSW). Any anal HPV infection was detected in 82.7% of HIV-infected MSM and in 51.5% of HIV- infected MSW (<i>P</i> < 0.001). High-risk HPV (HR-HPV) prevalence was higher among MSM (47.4%) than MSW (25.0%; <i>P</i> = 0.002). The HR-HPV types identified most frequently were HPV 16 (11%), HPV 18 (9.9%), and HPV 58 (5%) in MSM, and HPV 58(11%) and HPV 16 (8.9%) in MSW. Prevalence of any HPV types in 9-valent vaccine types was higher among MSM than MSW (47.4% vs 22.1%. <i>P</i> = 0.001). Abnormal anal cytology was more commonly detected in MSM than MSW (42.9% vs.19.1%, <i>P</i> < 0.001). In HIV-infected MSM, higher number of lifetime male sex partners was significantly associated with any anal HPV infection, but age was a significant risk factor associated with anal HR-HPV infection.</p><p>Conclusion</p><p>Anal HPV infection was highly prevalent in HIV-infected MSM in Korea, and also commonly found in HIV-infected MSW. In HIV-infected MSM, the significant risk factor for being infected with any HPV infection was lifetime number of male sexual partners, and with anal oncogenic HPV infection was age.</p></div