Effect of Influenza Vaccine in Patients With Kidney Transplant

BACKGROUND

Among infectious diseases, influenza is the most common cause of infection in Japan and worldwide. We aimed to evaluate the effect of influenza vaccination in kidney transplantation (KTx) recipients.

METHODS

We retrospectively evaluated the records of 98 participants who underwent KTx at our institution between March 2009 and May 2016. All patients received tacrolimus or cyclosporine, mycophenolate mofetil, and methylprednisolone for maintenance immunosuppression after KTx. In accordance with the criteria of our institution, everolimus was administered for the maintenance of immunosuppression after KTx. We compared the rate of influenza infection during the 2016-2017 season (8 months, from October 2016-May 2017) between KTx patients treated with 1 or 2 doses of influenza vaccine (treatment group, n = 71) and KTx patients who did not receive a vaccine (nontreatment group, n = 27).

RESULTS

Among patient characteristics, only the prevalence of diabetes mellitus differed significantly between the groups (treatment group: 9.9%, 7 of 71 patients; nontreatment group: 29.6%, 8 of 21 patients; P = .02). Influenza infection occurred at similar rates in the 2 groups (treatment group, 5.63% 4 of 71 patients; nontreatment group: 3.70%, 1 of 27 patients; P = .70).

CONCLUSIONS

Among KTx patients managed in our institution, treatment with 1 or 2 doses of influenza vaccine did not reduce the rate of influenza infection in the 2016-2017 season, suggesting that influenza vaccination may currently be ineffective in KTx patients.

Discovery of Cryoprotective Activity in Human Genome-Derived Intrinsically Disordered Proteins

Intrinsically disordered proteins (IDPs) are an emerging phenomenon. They may have a high degree of flexibility in their polypeptide chains, which lack a stable 3D structure. Although several biological functions of IDPs have been proposed, their general function is not known. The only finding related to their function is the genetically conserved YSK₂ motif present in plant dehydrins. These proteins were shown to be IDPs with the YSK₂ motif serving as a core region for the dehydrins’ cryoprotective activity. Here we examined the cryoprotective activity of randomly selected IDPs toward the model enzyme lactate dehydrogenase (LDH). All five IDPs that were examined were in the range of 35–45 amino acid residues in length and were equally potent at a concentration of 50 μg/mL, whereas folded proteins, the PSD-95/Dlg/ZO-1 (PDZ) domain, and lysozymes had no potency. We further examined their cryoprotective activity toward glutathione S-transferase as an example of the other enzyme, and toward enhanced green fluorescent protein as a non-enzyme protein example. We further examined the lyophilization protective activity of the peptides toward LDH, which revealed that some IDPs showed a higher activity than that of bovine serum albumin (BSA). Based on these observations, we propose that cryoprotection is a general feature of IDPs. Our findings may become a clue to various industrial applications of IDPs in the future.

Large-scale aggregation analysis of eukaryotic proteins reveals an involvement of intrinsically disordered regions in protein folding

A subset of the proteome is prone to aggregate formation, which is prevented by chaperones in the cell. To investigate whether the basic principle underlying the aggregation process is common in prokaryotes and eukaryotes, we conducted a large-scale aggregation analysis of ~500 cytosolic budding yeast proteins using a chaperone-free reconstituted translation system, and compared the obtained data with that of ~3,000 Escherichia coli proteins reported previously. Although the physicochemical properties affecting the aggregation propensity were generally similar in yeast and E. coli proteins, the susceptibility of aggregation in yeast proteins were positively correlated with the presence of intrinsically disordered regions (IDRs). Notably, the aggregation propensity was not significantly changed by a removal of IDRs in model IDR-containing proteins, suggesting that the properties of ordered regions in these proteins are the dominant factors for aggregate formation. We also found that the proteins with longer IDRs were disfavored by E. coli chaperonin GroEL/ES, whereas both bacterial and yeast Hsp70/40 chaperones have a strong aggregation-prevention effect even for proteins possessing IDRs. These results imply that a key determinant to discriminate the eukaryotic proteomes from the prokaryotic proteomes in terms of protein folding would be the attachment of IDRs.

Structural changes of homodimers in the PDB

Protein complexes are involved in various biological phenomena. These complexes are intrinsically flexible, and structural changes are essential to their functions. To perform a large-scale automated analysis of the structural changes of complexes, we combined two original methods. An application, SCPC, compares two structures of protein complexes and decides the match of binding mode. Another application, Motion Tree, identifies rigid-body motions in various sizes and magnitude from the two structural complexes with the same binding mode. This approach was applied to all available homodimers in the Protein Data Bank (PDB). We defined two complex-specific motions: interface motion and subunit-spanning motion. In the former, each subunit of a complex constitutes a rigid body, and the relative movement between subunits occurs at the interface. In the latter, structural parts from distinct subunits constitute a rigid body, providing the relative movement spanning subunits. All structural changes were classified and examined. It was revealed that the complex-specific motions were common in the homodimers, detected in around 40% of families. The dimeric interfaces were likely to be small and flat for interface motion, while large and rugged for subunit-spanning motion. Interface motion was accompanied by a drastic change in contacts at the interface, while the change in the subunit-spanning motion was moderate. These results indicate that the interface properties of homodimers correlated with the type of complex-specific motion. The study demonstrates that the pipeline of SCPC and Motion Tree is useful for the massive analysis of structural change of protein complexes.

Difficulty of confining recalcitrant tuberculosis patients in isolation wards in Japan, 2013-2014

OBJECTIVES

In Japan, approximately 7000 smear-positive tuberculosis (TB) cases were reported in 2014. According to the law, such patients must be isolated in a TB ward until they become at least sputum smear-negative. However, there are some recalcitrant patients who are difficult to isolate because of problematic behaviors. This study was conducted to characterize recalcitrant TB patients and determine why they left the hospitals and how they were followed up after they left.

STUDY DESIGN

Cross-sectional study.

METHODS

We sent a self-administered questionnaire to the hospitals in Japan with over 11 TB isolation beds, asking about recalcitrant TB inpatients from April 2013 through March 2014, in terms of demographic information, the reasons why they left, and how they were followed up.

RESULTS

A total of 38 recalcitrant patients were reported, of whom 15 (39.5%) self-discharged, eight (21.0%) were discharged, and 15 (39.5%) were transferred. Thirty-three (86.8%) were males. The main reason (52.6%) why the patients were considered recalcitrant was related to psychiatric problems. However, nine (23.6%) patients physically assaulted or insulted the staff members. Thirty-six (94.7%) were able to continue anti-TB treatment after they left the original hospital.

CONCLUSION

Although the number of recalcitrant TB patients who were abusive was small, there should be TB facilities with law enforcement officials readily available to enforce isolation.

Rules for connectivity of secondary structure elements in protein: Two-layer αβ sandwiches

In protein structures, the fold is described according to the spatial arrangement of secondary structure elements (SSEs: α-helices and β-strands) and their connectivity. The connectivity or the pattern of links among SSEs is one of the most important factors for understanding the variety of protein folds. In this study, we introduced the connectivity strings that encode the connectivities by using the types, positions, and connections of SSEs, and computationally enumerated all the connectivities of two-layer αβ sandwiches. The calculated connectivities were compared with those in natural proteins determined using MICAN, a nonsequential structure comparison method. For 2α-4β, among 23,000 of all connectivities, only 48 were free from irregular connectivities such as loop crossing. Of these, only 20 were found in natural proteins and the superfamilies were biased toward certain types of connectivities. A similar disproportional distribution was confirmed for most of other spatial arrangements of SSEs in the two-layer αβ sandwiches. We found two connectivity rules that explain the bias well: the abundances of interlayer connecting loops that bridge SSEs in the distinct layers; and nonlocal β-strand pairs, two spatially adjacent β-strands located at discontinuous positions in the amino acid sequence. A two-dimensional plot of these two properties indicated that the two connectivity rules are not independent, which may be interpreted as a rule for the cooperativity of proteins.

Efficacy and safety of osteoporosis medications in a rat model of late-stage chronic kidney disease accompanied by secondary hyperparathyroidism and hyperphosphatemia

This study showed that bisphosphonate was safe and effective for the treatment of bone disorders in stage 4 chronic kidney disease (CKD) rats. Intermittent teriparatide therapy showed an anabolic action on bone even under secondary hyperparathyroidism conditions without having an adverse effect on mineral metabolism in late-stage CKD.

INTRODUCTION

Patients with late-stage CKD are at high risk for fragility fractures. However, there are no consensus on the efficacy and safety of osteoporosis medications for patients with late-stage CKD. In the present study, we aimed to examine the efficacy and safety of alendronate (ALN) and teriparatide (TPD) for treating bone disorder in late-stage CKD with pre-existing secondary hyperparathyroidism using a rat model of CKD.

METHODS

Male 10-week-old Sprague-Dawley rats were subjected to a 5/6 nephrectomy or sham surgery and randomized into the following four groups: sham, vehicle (saline subcutaneous (sc) daily), ALN (50 μg/kg sc daily), and TPD (40 μg/kg sc daily). Medications commenced at 24 weeks of age and continued for 4 weeks. Micro-computed tomography, histological analysis, infrared spectroscopic imaging, and serum assays were performed.

RESULTS

Nephrectomized rats developed hyperphosphatemia, secondary hyperparathyroidism (SHPT), and high creatinine, equivalent to CKD stage 4 in humans. ALN suppressed the bone turnover and increased the degree of mineralization in cortical bone, resulting in an improvement in the mechanical properties. TPD further increased the bone turnover and significantly increased the degree of mineralization, micro-geometry, and bone volume, resulting in a significant improvement in the mechanical properties. Both ALN and TPD had no adverse effect on renal function and mineral metabolism.

CONCLUSIONS

BP is safe and effective for the treatment of bone disorders in stage 4 CKD rats. Intermittent TPD therapy showed an anabolic action on bone even under SHPT conditions without having an adverse effect on mineral metabolism in late-stage CKD.

Autoimmune arthritis deteriorates bone quantity and quality of periarticular bone in a mouse model of rheumatoid arthritis

This study showed that autoimmune arthritis induces especially severe osteoporosis in the periarticular region adjacent to inflamed joints, suggesting that arthritis increases the fragility fracture risk near inflamed joints, which is frequently observed in patients with RA.

INTRODUCTION

Periarticular osteoporosis near inflamed joints is a hallmark of early rheumatoid arthritis (RA). Here we show that rheumatic inflammation deteriorates the bone quality and bone quantity of periarticular bone, thereby decreasing bone strength and toughness in a mouse model of RA.

METHODS

Female BALB/c mice and SKG mice, a mutant mouse model of autoimmune arthritis on the BALB/c background, were used. At 12 weeks of age, BALB/c mice underwent either Sham surgery or bilateral ovariectomy (OVX), and SKG mice underwent intraperitoneal injection of mannan to induce arthritis. Eight weeks later, the mice were killed and the femurs and tibias were subjected to micro-computed tomography, Fourier transform infrared (FTIR) spectroscopic imaging, X-ray diffraction, histology, and mechanical testing.

RESULTS

SKG mice developed significant trabecular bone loss in both the distal metaphysis of the femur and the lumbar vertebral body, but the extent of the bone loss was more severe in the distal metaphysis. Neither SKG nor OVX mice exhibited changes in the geometry and matrix properties of the diaphysis of the femur, whereas SKG mice, but not OVX mice, did exhibit changes in these properties in the distal metaphysis of the femur. Bone strength and fracture toughness of the distal metaphysis of the tibia adjacent to the inflamed ankle joint were significantly decreased in SKG mice.

CONCLUSIONS

Autoimmune arthritis induces periarticular osteoporosis, characterized by deterioration of cortical bone geometry and quality as well as by trabecular bone loss, leading to severe bone fragility in periarticular bone adjacent to inflamed joints.

Itinerary profiling to analyze a large number of protein-folding trajectories

Understanding how proteins fold through a vast number of unfolded states is a major subject in the study of protein folding. Herein, we present itinerary profiling as a simple method to analyze molecular dynamics trajectories, and apply this method to Trp-cage. In itinerary profiling, structural clusters included in a trajectory are represented by a bit sequence, and a number of trajectories, as well as the structural clusters, can be compared and classified. As a consequence, the structural clusters that characterize the foldability of trajectories were able to be identified. The connections between the clusters were then illustrated as a network and the structural features of the clusters were examined. We found that in the true folding funnel, Trp-cage formed a left-handed main-chain topology and the Trp6 side-chain was located at the front of the main-chain ring, even in the initial unfolded states. In contrast, in the false folding funnel of the pseudo-native states, in which the Trp6 side-chain is upside down in the protein core, Trp-cage had a right-handed main-chain topology and the Trp side-chain was at the back. The initial topological partition, as determined by the main-chain handedness and the location of the Trp residue, predetermines Trp-cage foldability and the destination of the trajectory to the native state or the pseudo-native states.

Evaluation of the Glasgow Prognostic Score in patients receiving chemoradiotherapy for stage III and IV esophageal cancer

High Glasgow Prognostic scores (GPSs) have been associated with poor outcomes in various tumors, but the values of GPS and modified GPS (mGPS) in patients with advanced esophageal cancer receiving chemoradiotherapy (CRT) has not yet been reported. We have evaluated these with respect to predicting responsiveness to CRT and long-term survival. Between January 2002 and December 2011, tumor responses in 142 esophageal cancer patients (131 men and 11 women) with stage III (A, B and C) and IV receiving CRT were assessed. We assessed the value of the GPS as a predictor of a response to definitive CRT and also as a prognostic indicator in patients with esophageal cancer receiving CRT. We found that independent predictors of CRT responsiveness were Eastern Cooperative Oncology Group (ECOG) performance status, GPS and cTNM stage. Independent prognostic factors were ECOG performance status and GPS for progression-free survival and ECOG performance status, GPS and cTNM stage IV for disease-specific survival. GPS may be a novel predictor of CRT responsiveness and a prognostic indicator for progression-free and disease-specific survival in patients with advanced esophageal cancer. However, a multicenter study as same regime with large number of patients will be needed to confirm these outcomes.

Randomized clinical trial of single-incision versus multiport laparoscopic colectomy

BACKGROUND

The efficacy and safety of single-incision laparoscopic colectomy (SILC) for colonic cancer remain unclear. The aim of this study was to determine the outcomes of SILC compared with multiport laparoscopic colectomy (MPLC) for colonic cancer.

METHODS

Patients with histologically proven colonic carcinoma located in the caecum, ascending, sigmoid or rectosigmoid colon, clinically diagnosed as stage 0-III by CT, were eligible for this study. Patients were randomized before surgery and underwent tumour dissection with complete mesocolic excision. Safety analyses were conducted according to randomization groups.

RESULTS

A total of 200 patients were enrolled and randomized to the MPLC (100 patients) or SILC (100 patients) arm. Surgical outcomes were similar between the MPLC and SILC arms, including duration of operation (mean 162 versus 156 min respectively; P = 0·273), blood loss (mean 8·8 versus 21·4 ml; P = 0·102), conversion to open laparotomy (2·0 versus 1·0 per cent; P = 0·561), reoperation (3·0 versus 3·0 per cent; P = 1·000), time to first flatus (both median 1 day; P = 0·155) and postoperative hospital stay (both median 6; P = 0·372). The total skin incision length was significantly shorter in the SILC arm (mean 4·4 cm versus 6·8 cm in the MPLC arm; P < 0·001). The median duration of analgesia use was 5 days in the MPLC and 4 days in the SILC arm (P = 0·485). Overall complication rates were equivalent (15·0 versus 12·0 per cent respecitvely; P = 0·680).

CONCLUSION

SILC is not superior to MPLC.

REGISTRATION NUMBER

UMIN000007220 (http://www.umin.ac.jp/ctr/index.htm).

Male sexual dysfunction after rectal cancer surgery: Results of a randomized trial comparing mesorectal excision with and without lateral lymph node dissection for patients with lower rectal cancer: Japan Clinical Oncology Group Study JCOG0212

BACKGROUND

We conducted a randomized controlled trial (JCOG0212) to determine whether the outcome of mesorectal excision (ME) alone for rectal cancer is not inferior to that of ME with lateral lymph node dissection (LLND). The present study focused on male sexual dysfunction after surgery.

METHODOLOGY

Eligibility criteria included clinical stage II/III rectal cancer, the lower margin of the lesion below the peritoneal reflection, the absence of lateral pelvic lymph node enlargement, and no preoperative radiotherapy. After confirmation of R0 resection by ME, patients were intraoperatively randomized. Questionnaires using the International Index of Erectile Function (IIEF-5) about the sexual function of men were collected before and 1 year after surgery. Sexual dysfunction incidence was defined as the ratio of patients showing sexual dysfunction after surgery relative to the number who had no erectile dysfunction before surgery.

RESULTS

Among 701 patients enrolled between June 2003 and August 2010, 472 males were included. Among them, 343 (73%) completed preoperative and postoperative questionnaires. According to the study protocol, the incidences of sexual dysfunction in patients who underwent ME alone and ME with LLND were 68% (17/25; 95%CI, 47-85%) and 79% (23/29; 95%CI, 60-92%), respectively (p = 0.37). Incidences of sexual dysfunction in patients with no or only mild erectile dysfunction before surgery who underwent ME alone and ME with LLND were 59% (48/81) and 71% (67/95), respectively (p = 0.15). Multivariate analysis identified age as the only risk factor for sexual dysfunction after surgery (p = 0.02).

CONCLUSIONS

LLND may not increase sexual dysfunction incidence after rectal cancer surgery. This incidence is associated with increased age. This trial is registered with ClinicalTrials.gov, number NCT00190541 and University Hospital Medical Information Network Clinical Trials Registry, number C000000034.