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.

Muscle-specific deletion of BDK amplifies loss of myofibrillar protein during protein undernutrition

Branched-chain amino acids (BCAAs) are essential amino acids for mammals and play key roles in the regulation of protein metabolism. However, the effect of BCAA deficiency on protein metabolism in skeletal muscle in vivo remains unclear. Here we generated mice with lower BCAA concentrations by specifically accelerating BCAA catabolism in skeletal muscle and heart (BDK-mKO mice). The mice appeared to be healthy without any obvious defects when fed a protein-rich diet; however, bolus ingestion of BCAAs showed that mTORC1 sensitivity in skeletal muscle was enhanced in BDK-mKO mice compared to the corresponding control mice. When these mice were fed a low protein diet, the concentration of myofibrillar protein was significantly decreased (but not soluble protein) and mTORC1 activity was reduced without significant change in autophagy. BCAA supplementation in drinking water attenuated the decreases in myofibrillar protein levels and mTORC1 activity. These results suggest that BCAAs are essential for maintaining myofibrillar proteins during protein undernutrition by keeping mTORC1 activity rather than by inhibiting autophagy and translation. This is the first report to reveal the importance of BCAAs for protein metabolism of skeletal muscle in vivo.

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.

'Transfer out' tuberculosis patients: treatment outcomes after cross-checking registers, 2012-2013, Lusaka, Zambia

SETTING

Lusaka, Zambia.

OBJECTIVE

To assess the actual treatment outcomes of 'transfer out' (TO) cases at a diagnostic centre in Lusaka, in the third and fourth quarters of 2012, and to see the impact of this cross-check in treatment success rates (TSR) in 2013 and early 2014.

DESIGN AND METHOD

In this retrospective cohort study, treatment outcomes for new bacteriologically positive tuberculosis (TB) cases referred from the diagnostic centre were reviewed and compared with those at the receiving treatment units.

RESULTS

Of 49 (58%) cases referred to three treatment units, the treatment outcomes of nine had to be updated at the diagnostic centre, which reduced the proportion of TO cases from 17.6% to 11.8% and increased the TSR to 70.6% from 64.7%.

CONCLUSION

The review and cross-checking of the TB registers at the diagnostic and treatment units led to a significant reduction in non-assessed cases, suggesting that the TB registers in the diagnostic and treatment units should be cross-checked regularly. There is also need for a complementary intervention to reduce the proportion of TOs associated with high loss to follow-up and non-evaluated TO rates.

mTORC1 is involved in the regulation of branched-chain amino acid catabolism in mouse heart

The branched‐chain α‐ketoacid dehydrogenase (BCKDH) complex regulates branched‐chain amino acid (BCAA) catabolism by controlling the second step of this catabolic pathway. In the present study, we examined the in vivo effects of treatment with an mTORC1 inhibitor, rapamycin, on cardiac BCKDH complex activity in mice. Oral administration of leucine in control mice significantly activated the cardiac BCKDH complex with an increase in cardiac concentrations of leucine and α‐ketoisocaproate. However, rapamycin treatment significantly suppressed the leucine‐induced activation of the complex despite similar increases in cardiac leucine and α‐ketoisocaproate levels. Rapamycin treatment fully inhibited mTORC1 activity, measured by the phosphorylation state of ribosomal protein S6 kinase 1. These results suggest that mTORC1 is involved in the regulation of cardiac BCAA catabolism.

Increased protein and mRNA expression of resistin after dexamethasone administration

Synthetic glucocorticoids such as dexamethasone are widely used to treat a variety of inflammatory and autoimmune conditions, but they may induce adverse events including hyperglycemia. To shed light on the effect and action mechanism of dexamethasone, we examined the alterations of gene expression levels caused by dexamethasone.Microarray analysis was performed on whole blood collected from 24 physically healthy subjects at baseline and after dexamethasone administration. The expression levels of resistin mRNA were found to be significantly increased after the dexamethasone administration. In a separate sample of 12 subjects, we examined plasma resistin protein levels and found that they were increased after dexamethasone administration. Furthermore, the plasma mRNA and protein levels of resistin were significantly higher in individuals who carried the A allele of RETN single nucleotide polymorphism rs3219175 than in those who did not carry the allele. There was no significant interaction between the genotype and dexamethasone administration. No significant correlation was found between plasma levels of cortisol and resistin. Consistent with previous studies, the genotype of RETN rs3219175 was a strong determinant of resistin levels. The present study showed that oral administration of dexamethasone increases the protein and mRNA levels of resistin irrespective of the rs3219175 genotype.

Dielectric-loaded surface plasmon polariton crossing waveguides using multimode interference

A low-loss low-crosstalk multimode interference (MMI) crossing design for dielectric-loaded surface plasmon polariton waveguides (DLSPPWs), which are SiO2 stripes on Au films, is demonstrated numerically and experimentally. DLSPPWs are compatible with strong surface plasmon polariton (SPP) field confinement and maintain relatively low propagation losses. Unlike simpler crossings without MMI structures, low insertion loss of 0.65 dB and low crosstalk of -20.27  dB is confirmed numerically at a crossing angle of 10° when using tilted mirror-imaged MMI crossings. Similar insertion losses were also confirmed experimentally. The proposed structure will be beneficial for plasmonic device miniaturization and flexible patterning of optical interconnections.

Optimizing the selection of patients with low rectal cancer for intersphincteric resection by evaluating vertical invasion to the levator and external sphincter

AIM

The indications for intersphincteric (ISR) anterior resection are not clearly defined. The aim of this study was to evaluate vertical extension of T2 or T3 low rectal cancer treated by rectal amputation to optimize patient selection for ISR.

METHOD

The abdominoperineal excision specimens of T2 or T3 low rectal cancer from 53 patients treated between 1992 and 2004 were retrospectively reviewed. Vertical invasion was quantified by measuring the shortest distance between the tumour and the striated muscle (T-SM), assuming that this represented the surgical margin that would have be achieved had an ISR been performed.

RESULTS

Involvement of the dentate line (DL) and intramural distal spread were independent risk factors for T-SM ≤ 2 mm. The T-SM was less when the inferior border of the tumour was on the distal side of the DL (r = 0.572, P < 0.001). The probability of involvement of the DL, intramural distal spread or either one of these being associated with T-SM ≤ 2 mm was 43, 46 and 43%, respectively. All patients without both intramural distal spread and involvement of the DL had T-SM > 2.

CONCLUSION

We recommend that ISR should only be performed for patients with T2 or T3 low rectal cancer in whom the lowest edge of the tumour is above the DL and there is no intramural distal spread. Such patients are relatively unlikely to have a T-SM ≤ 2 mm.