Short-term outcomes of second kidney transplantation compared with those of first transplantation in Japanese patients: a single-center, retrospective, observational study.

BACKGROUND: Among patients who undergo kidney transplantation, a subsequent second kidney transplantation (TX2) is often necessary. The TX2 outcomes remain controversial, however, and only limited data are available on clinical outcomes of TX2 in Japanese patients. This study aimed to assess graft and patient survival rates of TX2 and compared these rates with those of first kidney transplantation (TX1) in Japanese patients. METHODS: Of the 898 kidney transplantations performed between 2010 and 2019 at our institution, 33 were TX2. We performed survival analysis using weighted Kaplan-Meier analysis and Cox proportional hazards analysis with propensity score matching, specifically inverse probability of treatment weighting (IPTW). RESULTS: Death-censored graft survival (DCGS) rates at 1, 3, and 5 years for the TX1 versus TX2 groups were 99.3, 97.9, and 95.0% versus 100, 96.0, and 91.2%, respectively. Overall survival (OS) rates at 1, 3, and 5 years for the TX1 versus TX2 groups were 99.4, 98.9, and 97.8% versus 100, 100, and 94.4%, respectively. Using the log-rank test, IPTW-weighted Kaplan-Meier curves showed no significant differences for TX1 versus TX2 in DCGS (p = 0.535) and OS (p = 0.302). On Cox proportional hazards analysis for TX2 versus TX1, the IPTW-adjusted hazard ratio (HR) for DCGS was 1.75 (95% CI, 0.28-10.9; p = 0.550) and for OS was 2.71 (95% CI, 0.40-18.55; p = 0.311). CONCLUSIONS: For patients who require TX2, this treatment is an acceptable option based on the short-term outcomes data for DCGS and OS.

Identification, characterization, and cloning of a novel aminoacylase, L-pipecolic acid acylase from Pseudomonas species.

L-Pipecolic acid is utilized as a vital component of specific chemical compounds, such as immunosuppressive drugs, anticancer reagents, and anesthetic reagents. We isolated and characterized a novel L-aminoacylase, N-acetyl-L-pipecolic acid-specific aminoacylase (LpipACY), from Pseudomonas sp. AK2. The subunit molecular mass of LpipACY was 45 kDa and was assumed to be a homooctamer in solution. The enzyme exhibited high substrate specificity toward N-acetyl-L-pipecolic acid and a high activity for N-acetyl-L-pipecolic acid and N-acetyl-L-proline. This enzyme was stable at a high temperature (60°C for 10 min) and under an alkaline pH (6.0-11.5). The N-terminal and internal amino acid sequences of the purified enzyme were STTANTLILRNG and IMASGGV, respectively. These sequences are highly consistent with those of uncharacterized proteins from Pseudomonas species, such as amidohydrolase and peptidase. We also cloned and overexpressed the gene coding LpipACY in Escherichia coli. Moreover, the recombinant LpipACY exhibited properties similar to native enzyme. Our results suggest that LpipACY is a potential enzyme for the enzymatic synthesis of L-pipecolic acid. This study provides the first description of the enzymatic characterization of L-pipecolic acid specific amino acid acylase.

Changes in Muscle Quality and Body Composition 1 Year After Hand-Assisted Laparoscopic Donor Nephrectomy in Living Kidney Donors.

OBJECTIVES: Our aim was to investigate effects of surgery on living donors' body composition and clarify factors related to it. MATERIALS AND METHODS: We evaluated preoperative computed tomography images of 335 living kidney donors (127 men, 209 women) to calculate 3 body composition parameters and changes with aging by sex: (1) skeletal muscle mass, quantified by skeletal muscle index; (2) fat distribution, calculated by visceral adipose tissue/subcutaneous adipose tissue ratio; and (3) muscle quality, quantified by intramuscular adipose tissue content. Thereafter, with pre- and postoperative computed tomography images from 75 living kidney donors (25 men, 50 women) after hand-assisted laparoscopic donor nephrectomy, we compared pre- and postoperative body composition changes. RESULTS: Annual change in intramuscular adipose tissue content with age was 0.0049 in men and 0.0091 in women. Of 75 patients, 49 had lower quality of muscle, intramuscular adipose tissue content was significantly higher after nephrectomy (P < .001), and median change in intramuscular adipose tissue content was 0.061 (range, 0.018-0.11) in men and 0.052 (range, 0.017-0.18) in women. Univariate analysis revealed that skeletal mass index and visceral adipose tissue/subcutaneous adipose tissue ratio changes were significantly different between the intramuscular adipose tissue content improvement and deterioration groups. Multivariate analysis revealed skeletal mass index change was an independent factor for intramuscular adipose tissue content change (P = .0019). Intramuscular adipose tissue content change was negatively correlated with skeletal mass index change (r = -0.40). CONCLUSIONS: Although muscle quality deteriorates after nephrectomy, maintaining muscle mass is important to retaining muscle quality.

Effects of cyclophosphamide administration on the in vitro fertilization of mice.

PURPOSE: To evaluate the oocyte fertilization ability and embryo growth after cyclophosphamide (CPA) treatment in mice. METHODS: Mice were treated with CPA at different doses (0-800 mg/kg body weight). The oocytes then were retrieved and evaluated for their in vitro fertilization efficiency. RESULTS: The average number of metaphase II (MII) oocytes significantly decreased by ≥400 mg/kg CPA administration. The fertilization rate also decreased in the group that was treated with ≥400 mg/kg CPA. However, after fertilization, the embryos demonstrated normal growth ability. Two weeks after CPA administration, the number of mice from which the oocytes could be retrieved markedly decreased, but the fertilization rate and development of morphological features in the embryos were similar to those of the controls. One month after CPA administration, the number of mice from which the oocytes could be retrieved, fertilization rate, and development of the morphological features in the embryos were similar to those of the controls. CONCLUSION: The number of oocytes decreased as the CPA administration level increased; however, the oocytes' potential for fertilization and development to the blastocyst stage was not significantly affected. One month after CPA administration, the number of oocytes and the potential for development into blastocysts were recovered.

Prediction of the in vitro developmental competence of early-cleavage-stage human embryos with time-lapse imaging and oxygen consumption rate measurement.

PURPOSE: To assess an embryo's ability to develop into a good-quality blastocyst during the early-cleavage stage using time-lapse imaging and the oxygen consumption rate. METHODS: In total, 942 zygotes had their oxygen consumption rates measured. In total, 282 zygotes were assessed by using time-lapse imaging. In total, 121 zygotes were examined by using both their oxygen consumption rate and time-lapse imaging. RESULTS: The embryos with moderate respiration rates of between 0.41 and 0.61 (×1014/mol s-1) on day 3 had a 22.1% chance of becoming good-quality blastocysts; those outside that range had a 14.3% chance. With the time-lapse system, when the first division was within 24 hours, 22.3% of the embryos grew to good blastocysts. After 24 hours, the rate dropped to 8.6%. The intervals between two consecutive cleavages were calculated and the duration of the second cell cycle was defined. When the time was between nine hours and 13 hours, there was a higher rate of good blastocysts. Regarding both criteria, when the embryos had progressed in the optimal range, a high percentage of them had become good blastocysts; it was 8.0% outside of that range. CONCLUSION: Individual embryos with the potential to develop into good-quality blastocysts could be selected at day 3 of culture using these systems.

Immunoenzymometric assay for recombinant methioninase in biological fluids.

Immunoassay for recombinant methioninase (rMETase), an anti-cancer agent, in biological sample was developed. Antisera were produced by immunizing rabbits with rMETase. The antisera were evaluated using radioiodine-labeled rMETase and good antisera for sensitive immunoassay were obtained. Horseradish peroxidase (HRP) was coupled to reduced IgG of K232 antiserum through bridging agent, N-(epsilon -maleimidocaproyloxy) sulfosuccinimide ester (sulfo-EMCS), to prepare enzyme-labeled antibody. IgG fraction of K231 antiserum was immobilized on microplate well. Two-site sandwich immunoenzymometric assay (IEMA) was developed using these antibodies and had good standard curve between 0.4 and 12 ng per well. For determination of rMETase in mouse plasma, sample was diluted 100-fold with dilution buffer containing protease inhibitors, because about 10% of rMETase immunoreactivity was lost for 2 h at room temperature. rMETase in mouse plasma could be determined by the proposed method in the range of 0.5-8 microg/ml and the method was validated. This novel IEMA, in substitution for the measurement of its enzyme activity, should be very useful not only for preclinical studies of rMETase but also for the clinical studies.