A multi-institutional, observational study of outcomes after catheter placement for peritoneal dialysis in Japan

BACKGROUND

This multi-institutional, observational study examined whether the outcomes after peritoneal dialysis (PD) catheter placement in Japan meet the audit criteria of the International Society for Peritoneal Dialysis (ISPD) guideline and identified factors affecting technique survival and perioperative complications.

METHODS

Adult patients who underwent first PD catheter placement for end-stage kidney disease between April 2019 and March 2021 were followed until PD withdrawal, kidney transplantation, transfer to other facilities, death, 1 year after PD start or March 2022, whichever came first. Primary outcomes were time to catheter patency failure and technique failure, and perioperative infectious complications within 30 days of catheter placement. Secondary outcomes were perioperative complications. Appropriate statistical analyses were performed to identify factors associated with the outcomes of interest.

RESULTS

Of the total 409 patients, 8 who underwent the embedded catheter technique did not have externalised catheters. Of the 401 remaining patients, catheter patency failure occurred in 25 (6.2%). Technical failure at 12 months after PD catheter placement calculated from cumulative incidence function was 15.3%. On Cox proportional hazards model analysis, serum albumin (hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27-0.70) and straight type catheter (HR 2.14; 95% CI 1.24-3.69) were the independent risk factors for technique failure. On logistic regression analysis, diabetes mellitus was the only independent risk factor for perioperative infectious complications (odds ratio 2.70, 95% CI 1.30-5.58). The occurrence rate of perioperative complications generally met the audit criteria of the ISPD guidelines.

CONCLUSION

PD catheter placement in Japan was proven to be safe and appropriate.

Brain charts for the human lifespan

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

Physical Exercise Improves Cognitive Function in Older Adults with Stage 3-4 Chronic Kidney Disease: A Randomized Controlled Trial

INTRODUCTION

Patients with chronic kidney disease (CKD) exhibit a higher probability of having cognitive impairment or dementia than those without CKD. The beneficial effects of physical exercise on cognitive function are known in the general older population, but more research is required in older adults with CKD.

METHODS

Eighty-one outpatients (aged ≥65 years) with CKD stage G3-G4 were assessed for eligibility. Among them, 60 were randomized (single-center, unblinded, and stratified) and 53 received the allocated intervention (exercise n = 27, control n = 26). Patients in the exercise group undertook group-exercise training at our facility once weekly and independent exercises at home twice weekly or more, for 24 weeks. Patients in the control group received general care. General and specific cognitive functions (memory, attention, executive, and verbal) were measured, and differences in their scores at baseline and at the 24-week follow-up visit were assessed between the 2 groups.

RESULTS

Forty-four patients completed the follow-up at 24 weeks (exercise n = 23, control n = 21). Patients in the exercise group showed significantly greater changes in Wechsler Memory Scale-Revised Logical Memory delayed recall (exercise effect: 2.82, 95% CI: 0.46-5.19, p = 0.03), and immediate and delayed recall (exercise effect: 5.97, 95% CI: 1.13-10.81, p = 0.02) scores than those in the control group.

CONCLUSIONS

The 24-week exercise intervention significantly improved the memory function in older adults with pre-dialysis CKD. This randomized controlled trial suggests that physical exercise is a useful nonpharmacological strategy for preventing cognitive decline in these patients.

Welfare receipt and the risk of vitamin D deficiency in Japanese patients on maintenance hemodialysis: a cross-sectional, retrospective study

BACKGROUND

Vitamin D deficiency is often observed in patients undergoing maintenance hemodialysis and is associated with significantly increased risk of overall mortality. Despite reports of poor nutrition/intake, vitamin D status among patients on maintenance hemodialysis receiving welfare remains unknown. This study investigated the vitamin D status in welfare recipients undergoing maintenance hemodialysis.

METHODS

This cross-sectional study investigated vitamin D status among 106 outpatients undergoing maintenance hemodialysis at two medical facilities in Japan. Patients were divided into welfare and non-welfare groups based on their status as of September 2018. Patients were divided into two categories: serum vitamin D deficiency, defined as serum 25(OH)D concentrations < 12 ng/mL, or non-deficiency. Vitamin D deficiency was used as a dependent variable, while welfare receipt was used as the main predictor variable.

RESULTS

Mean [± standard deviation] patient age, median [interquartile range] body mass index, and hemodialysis duration were 66.9 [± 10.8] years, 21.5 [19.6, 24.3] kg/m2, and 7.9 [2.9, 12.3] years, respectively. Among 106 patients, 45 were women (42.5%) and 16 (15.1%) were receiving welfare. The welfare group had a higher diabetes prevalence (P = 0.003) and significantly lower median serum 25-hydroxyvitamin D concentrations (11.5 [8.7, 14.0] vs. 14.8 [11.2, 19.9] ng/mL, P = 0.005). Multiple logistic regression analysis revealed that welfare receipt was a significant risk factor for vitamin D deficiency (odds ratio [95% confidence interval], 4.41 [1.08, 18.07]).

CONCLUSIONS

Welfare recipients undergoing maintenance hemodialysis are at significantly increased risks of vitamin D deficiency compared with patients not receiving welfare.

Bone responsiveness to parathyroid hormone is negatively associated with parathyroid hormone-lowering drug use in patients undergoing hemodialysis: a cross-sectional study

BACKGROUND

Parathyroid hormone (PTH) acts on bone to indirectly increase the number and activity of osteoclasts. Thus, PTH has a stimulatory effect on bone resorption and upregulates bone turnover. However, the responsiveness of bone to PTH varies widely among patients receiving dialysis. In fact, relative to the serum PTH level, the level of serum tartrate-resistant acid phosphatase-5b (TRACP-5b), a bone resorption marker derived from osteoclasts, varies as well. This study aimed to examine factors related to bone responsiveness to PTH in patients undergoing chronic hemodialysis (HD).

METHODS

This study included patients receiving chronic HD in Kawasaki Municipal Tama Hospital (Kanagawa, Japan) and Yonaha Medical Clinic (Okinawa, Japan) and excluded patients who received HD for less than 6 months, those who received a combination of HD and peritoneal dialysis, and those who had cancer bone metastases or myeloma. The TRACP-5b/intact PTH (iPTH) ratio was created as an index of bone responsiveness to PTH, categorized into tertiles (low, medium, and high), and a cross-sectional study was conducted. P < 0.05 indicated statistically significant differences.

RESULTS

One hundred and six patients were analyzed. Age (P = 0.010), body mass index (BMI) (P = 0.003), use of calcium-sensing receptor (CaSR) agonists (P = 0.008), use of vitamin D receptor activators (VDRAs) (P = 0.012), plasma iPTH level (P < 0.001), serum 1,25(OH)₂D level (P = 0.003), and serum TRACP-5b level (P < 0.001) were significantly different among the three categories. In the single linear regression analysis, age (P = 0.016), corrected serum calcium level (P = 0.007), and ln [1,25(OH)₂D] (P = 0.044) showed a significant positive correlation with ln [TRACP-5b/iPTH], whereas BMI (P = 0.026), use of CaSR agonists (P = 0.001), use of VDRAs (P = 0.009), and serum phosphorus level (P = 0.018) showed a significant negative correlation. Upon conducting multiple linear regression analysis incorporating significant variables in the single linear regression analysis, a significant negative correlation was observed between the TRACP-5b/iPTH ratio and intravenous administration of a CaSR agonist (etelcalcetide) and/or a VDRA (calcitriol or maxacalcitol) in all the adjusted models.

CONCLUSIONS

Bone responsiveness to PTH is negatively correlated with the intravenous administration of a CaSR agonist and/or a VDRA in patients undergoing chronic HD.

P1163IMPACTS OF IRON-BASED PHOSPHATE BINDER ON ANEMIA AND IRON METABOLISM IN PERITONEAL DIALYSIS PATIENTS: A CROSS-SECTIONAL, LONGITUDINAL MULTICENTER STUDY IN KANAGAWA, JAPAN

Background and Aims

Iron-based phosphate binder (IPB) is a noncalcium phosphate binder that demonstrated sustained serum phosphorus control, good tolerability and lower pill burden compared with sevelamer carbonate in a Phase 3 study conducted in dialysis patients. These efficacy of IPB has been demonstrated for hemodialysis (HD) patients, but few studies have focused on patients undergoing peritoneal dialysis (PD). We evaluated efficacy of IPB and focused on effects for anemia and iron metabolism in patients on PD.

Method

This study was a cross-sectional, longitudinal multicenter study conducted by PD OASIS, organized committee in Kanagawa Japan. We analyzed the effects of IPB during a 6 months observation period in chronic kidney disease patients on PD who had administrated IPB, Ferric citrate hydrate and Sucroferric oxyhydroxide, between 2017 and 2019. The primary endpoint was the changes of phosphate, and several secondary endpoints were assessed: calcium, intact PTH, RBC, hemoglobin, MCH, RDW-VC, Fe, TSAT, Ferritin, albumin, CRP, monthly dosage of Erythropoietin stimulating agents (ESA) and ESA resistance index (ERI).

In addition, we assessed the association between these markers and iron metabolism utilizing multivariate logistic regression analysis.

Results

A total of 102 patients were registered in the study who had received IPB.

The initial doses of Ferric citrate hydrate and Sucroferric oxyhydroxide were 1010.9 ±400.9 mg and 941.7 ±502.9 mg daily, finally increased to 1213.6 ±559.9 mg and 1310.0 ±521.8 mg respectively at the end of the observation.

We observed a significant reduction of serum phosphate to 5.27 ± 0.98 mg/dL from 6.56 ± 1.52 mg/dL with follow-up of six months (p &lt; 0.01). At the end of the study, 76.4% of participants had achieved the target of less than 6 mg/dL. The hemoglobin, TSAT and Ferritin increased significantly from 10.47 ±1.26 g/dl, 27.95 ±11.05 % and 139.0 ±147.6 ng/mL to 11.17 ±1.16 g/dl, 40.46 ±15.00 % and 305.9 ±232.0 ng/mL respectively in six months (p &lt; 0.01).

No significant changes of serum calcium, intact parathyroid hormone (PTH) and CRP occurred over the study period.

The monthly dosage of ESA was significantly decreased after administration with IPB and ERI significantly improved to 0.11±0.12 (μg/month/kg/g Hb) from 0.21±0.16 (μg/month/kg/g Hb) (p&lt;0.01). Hemoglobin overshoot, an increase of more than 12 g/dl, was observed in 27.5% patients. This related low MCH and high RDW-VC at baseline which was proven by multivariate logistic regression.

Additionally, we assessed the factors of ferritin increase because it was remarkable in follow-up six months compared to HD patients. In multivariate analysis, phosphate (Odds ratio 5.85, 95%CI 1.18-91.77, p=0.027), intact PTH (0.99, 0.97-1.15, p=0.015), hemoglobin (Odds ratio 0.10, 95%CI 0.05-0.59, p=0.025), RBC (Odds ratio 1.16, 95%CI 1.04-1.41, p=0.003), and RDW-CV (Odds ratio 0.44, 95%CI 0.10-0.99, p=0.046) were significantly associated with ferritin increase more than 300 ng/ml ,after adjusted.

Conclusion

This study confirmed the efficacy of Iron-based phosphate binder, Ferric citrate hydrate and Sucroferric oxyhydroxide, in the treatment of hyperphosphatemia in PD patients. In addition, IBP caused secondary effects of anemia improvement and ESA dosage reduction resulting in ERI improvement. However, in this study, the increase in ferritin levels was remarkable. It may be because PD does not lose iron by treatment compared to HD. Therefore, we should check iron metabolism more frequently for PD patients taking IPB than HD patients. It is necessary to further investigate the effects of IPB on anemia and iron metabolism in PD patients.

Longitudinal changes in 18 F-THK5351 positron emission tomography in corticobasal syndrome

BACKGROUND AND PURPOSE

Corticobasal syndrome (CBS) is pathologically characterized by tau deposits in neuronal and glial cells and by reactive astrogliosis. In several neurodegenerative disorders, ¹⁸ F-THK5351 has been observed to bind to reactive astrocytes expressing monoamine oxidase B. In this study, the aim was to investigate the progression of disease-related pathology in the brains of patients with CBS using positron emission tomography with ¹⁸ F-THK5351.

METHODS

Baseline and 1-year follow-up imaging were acquired using magnetic resonance imaging and positron emission tomography with ¹⁸ F-THK5351 in 10 subjects: five patients with CBS and five age-matched normal controls (NCs).

RESULTS

The 1-year follow-up scan images revealed that ¹⁸ F-THK5351 retention had significantly increased in the superior parietal gyrus of the patients with CBS compared with the NCs. The median increases in ¹⁸ F-THK5351 accumulation in the patients with CBS were 6.53% in the superior parietal gyrus, 4.34% in the precentral gyrus and 4.33% in the postcentral gyrus. In contrast, there was no significant increase in the regional ¹⁸ F-THK5351 retention in the NCs.

CONCLUSIONS

Longitudinal increases in ¹⁸ F-THK5351 binding can be detected over a short interval in the cortical sites of patients with CBS. A monoamine oxidase B binding radiotracer could be useful in monitoring the progression of astrogliosis in CBS.

Mild cognitive impairment in older adults with pre-dialysis patients with chronic kidney disease: Prevalence and association with physical function

AIM

Chronic kidney disease (CKD) is a risk factor for declining cognitive and physical function. However, the prevalence of mild cognitive impairment (MCI) and its relationship with physical function is not clear. Therefore, our aim was to evaluate the prevalence of MCI and the relationship between MCI and physical function among older adults with pre-dialysis CKD.

METHODS

We conducted a cross-sectional study of 120 patients, aged ≥65 years (mean age, 77.3 years), with pre-dialysis CKD but without probable dementia (Mini Mental State Examination <24). MCI was evaluated using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). For analysis, patients were classified into two cognitive function groups: normal (MoCA-J ≥ 26) and MCI (MoCA-J < 26). Physical, clinical, and biochemical parameters were compared between the groups. Logistic and linear regression analyses were used to evaluate the specific association between cognitive and physical function.

RESULTS

Seventy-five (62.5%) patients belonged to the MCI group. Significant differences between the two groups were identified for gait speed, balance, age, and haemoglobin concentration. After adjustment for covariates, only gait speed was significantly associated with MCI (odds ratio, 0.06; 95% confidence interval, 0.009-0,411).

CONCLUSION

The prevalence of MCI among older adults with pre-dialysis CKD was as high as 62.5%. The association between MCI and reduced gait speed supports the possible interaction between physical and cognitive functions and the need for early screening.

Predictive Factors for Withdrawal from Peritoneal Dialysis: A Retrospective Cohort Study at Two Centers in Japan

Peritoneal dialysis (PD) is recognized as an excellent method of dialysis because the therapy is gentle, continuous, and cost-effective. However, a large number of patients must unfortunately transfer from PD to hemodialysis because of peritonitis or fluid overload in the early phase after PD initiation. In the present study, we reviewed clinical indicators before PD initiation to try to identify predictive factors for early withdrawal from PD.For this retrospective cohort study at two hospitals between March 2003 and October 2016, we defined withdrawal from PD as the induction of combination therapy, transfer to hemodialysis, or death. Data about clinical indicators before PD induction-namely age, sex, presence of diabetes mellitus, past history of cardiovascular disease (CVD), body mass index, primary kidney disease, and blood biochemistry-were collected from medical records. The primary outcome was duration of PD until withdrawal.We analyzed 151 PD patients (median age: 62.5 years; 94 men; 74 with diabetes mellitus; median duration of PD: 30.2 months). Univariate Cox regression analysis showed that the hazard ratio (HR) for withdrawal was 1.08 [95% confidence interval (CI): 1.04 to 1.12; p < 0.001] per 1 mg/L increase in β₂-microglobulin (β₂MG), 0.65 (95% CI: 0.46 to 0.93; p = 0.02) per 1 g/dL decrease in serum albumin, and 1.07 (95% CI: 1.02 to 1.11; p = 0.01) per 1 g per gram creatinine increase in daily urinary protein excretion. Using multivariate Cox regression analysis, β₂MG (HR: 1.08; 95% CI: 1.04 to 1.12; p < 0.001) and past history of CVD (HR: 1.47; 95% CI: 1.02 to 2.13; p = 0.04) were factors predictive for withdrawal from PD. Kaplan-Meier analysis showed that the technique survival rate was significantly different in the two groups defined as having a serum β₂MG level above or below the measured median (p = 0.047).Serum β₂MG at PD initiation and past history of CVD are high-risk factors for withdrawal from PD. Special focus should be placed on the care and management of patients found to have a high risk of withdrawal at the time of PD induction.

Long-Term Prognosis of Peritoneal Dialysis Patients with a Re-embedded Catheter

Upon peritoneal dialysis (PD) discontinuation in frail patients, we have re-embedded the catheter and left it subcutaneously buried. However, we have not evaluated the long-term prognosis of those patients after the procedure or the complications associated with buried catheters. We therefore aimed to clarify the long-term prognosis of patients with a re-embedded catheter and to identify any associated complications.The outcomes of 10 patients having a catheter that was re-embedded between February 2010 and May 2016 were assessed by interviewing the patients or their families (when possible), and by reviewing medical records.Catheter re-embedding to reduce the surgical burden was elected by 7 patients, and 3 patients underwent re-embedding because they wanted to resume PD in the future. By the time of the interviews, 6 patients had already died of causes that were unrelated either to the buried catheter or infection. No abnormality was found in any buried catheter. A re-embedded catheter was later externalized to resume PD in 1 of the 4 patients who survived.Catheter re-embedding is safe and allows for PD resumption at the terminal stage of dialysis.

Impact of videogame play on the brain's microstructural properties: cross-sectional and longitudinal analyses

Videogame play (VGP) has been associated with numerous preferred and non-preferred effects. However, the effects of VGP on the development of microstructural properties in children, particularly those associated with negative psychological consequences of VGP, have not been identified to date. The purpose of this study was to investigate this issue through cross-sectional and longitudinal prospective analyses. In the present study of humans, we used the diffusion tensor imaging mean diffusivity (MD) measurement to measure microstructural properties and examined cross-sectional correlations with the amount of VGP in 114 boys and 126 girls. We also assessed correlations between the amount of VGP and longitudinal changes in MD that developed after 3.0±0.3 (s.d.) years in 95 boys and 94 girls. After correcting for confounding factors, we found that the amount of VGP was associated with increased MD in the left middle, inferior and orbital frontal cortex; left pallidum; left putamen; left hippocampus; left caudate; right putamen; right insula; and thalamus in both cross-sectional and longitudinal analyses. Regardless of intelligence quotient type, higher MD in the areas of the left thalamus, left hippocampus, left putamen, left insula and left Heschl gyrus was associated with lower intelligence. We also confirmed an association between the amount of VGP and decreased verbal intelligence in both cross-sectional and longitudinal analyses. In conclusion, increased VGP is directly or indirectly associated with delayed development of the microstructure in extensive brain regions and verbal intelligence.

Using a Peritoneal Dialysis Access Simulator in Surgical Training for Nephrologists

In Japan, peritoneal dialysis (PD) catheter insertion has been performed by both nephrologists and surgeons. However, nephrologists have fewer opportunities to train in the insertion procedure. We therefore used a PD access simulator to provide training in this operative technique for nephrologists. A PD access simulator developed by Terumo Medical Corporation was used for the training. The simulator uses a mannequin made of acrylic resin. The abdominal wall of a pig is attached to the abdominal area, and a plastic bag represents the abdominal cavity. The simulator enables the surgical procedure to be performed from skin incision to PD catheter insertion. Between October 2011 and December 2013, 3 supervising doctors used the simulator to guide 17 nephrologists with no experience through a PD catheter insertion. One-on-one training was provided in a single 2- or 3-hour session. In a questionnaire survey after the training, trainees gave high marks to the handling of surgical instruments, the environment of the operating room, and the surgical guidance during training. However, the supervising doctors required the ability to respond flexibly, because trainees had individual differences in skills. The PD access simulator might be useful for providing guided training in operative technique for PD catheter insertion.

Abstract OT3-2-03: An efficacy and safety trial of preoperative chemo-endocrine therapy in luminal B (HER2-negative) breast cancer: A prospective multi-institutional study

Background: The St.Gallen consensus guideline recommends the sequential administration chemotherapy followed by of endocrine therapy as postoperative therapy for the higher risk ER-positive breast cancer patients based on results of a single study (Albain et al, Lancet 2009). In metastatic settings however, several trials conducted in the 1980's demonstrated that tumor response rates were higher when chemotherapy and tamoxifen were concomitantly administered, than when chemotherapy and tamoxifen administered were given sequentially. In the preoperative settings, pathological complete response (pCR) rate can be used a surrogate marker to predict event-free survival or overall survival in Luminal B(HER2-negative) breast cancer. We therefore designed a prospective randomized safety and efficacy trial in order to test a hypothesis that the concomitant administration of an aromatase inhibitor and chemotherapy improves pathological complete response(pCR) rate than chemotherapy alone in the preoperative setting.

Trial design: The trial is a prospective, multi-center, randomized comparison of chemotherapy alone versus concomitant chmo-endocrine therapy evaluating the efficacy in terms of pCR rate and safety in preoperative settings in patients with Luminal B (HER2-negative) breast cancer. 94 patients were to be accrued into this trial.

- arm A (control): 12 cycles of weekly paclitaxel(80mg/m2) followed by 4 cycles of every 3-week AC(Doxorubicine 60mg/m2, Cyclophosphamide 600mg/m2).

- arm B (experimental): The same chermotherapy as arm A and anastrozole in postmenopausal patients or anastrozole+leuprolerine in premenopansal patients.

Eligibility criteria: 1)Female patients with operable and histologically confirmed invasive breast cancer; 2)HER2-negative; 3)Either ER -positive or PgR-positive; 4)Either Ki67-LI&gt; = 14% and NG&gt; = 2 or NG = 3 regardless of Ki67-LI.

Endpoints : Primary endpoint is the pCR rate. Secondary endpoints are the clinical response rate(RECIST), the adverse events(CTC-AE ver.4.0), the breast conserving rate and the health related quality of life.

Statistical Considerations : The pCR rates in the control arm and the experimental arm are expected to be 10% and 25%, respectively. In order to show the superiority of the experimental arm with an alfa error at 5% and beta error at 20%, calculated number of patients needed were 96.

Present Accrual and Target Accrual: As of June 06, 2013, 18 patients were enrolled from 8 institutions.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT3-2-03.

A rapid HPLC with evaporative light scattering method for quantification of forskolin in multi-herbal weight-loss solid oral dosage forms

A rapid reverse-phase HPLC method with evaporative light scattering detection (ELSD) was developed for the determination of forskolin in weight loss multi-herbals products. The analysis was performed by water-acetonitrile gradient elution at a temperature of 40 degrees C and a flow rate of 1.0 mL/min. The evaporator tube temperature of ELSD was set at 35 degrees C, and with the nebulizing gas flow-rate (pressure) of 3.0 bar. The method was validated for linearity, accuracy, precision and limits of detection (LOD) and quantification (LOQ). Good linear relationships were obtained with correlation coefficients exceeding 0.9995. The average recovery of forskolin ranged from 99.4% to 100.4% with RSDs below 3%. The percent relative standard deviations (%RSD) of intra- and inter-day precision varied by less than 2.1%. LOD and LOQ were 0.95 microg/ml and 3.21 microg/ml, respectively. The validated ELSD method permits a shorter determination time without compromising accuracy and demonstrates that it can be used for quantification of forskolin incorporated in multi-herbal solid oral dosage forms.

Psychiatric, somatic, and gastrointestinal disorders, and Helicobacter pylori infection in children with recurrent abdominal pain

AIMS

To examine the utility of the Rome II criteria in children with recurrent abdominal pain (RAP) and compare them to those who met Apley's criteria and those who met neither criteria.

METHODS

Prospective study in general paediatric clinics in Komagane, Japan. Children with abdominal pain were classified into those who met Rome II criteria, those who met Apley's criteria, and those who met neither.

RESULTS

A total of 182 children with RAP participated; 45 children met Rome II criteria, 55 met Apley's criteria, and 82 met neither. Children who met Rome II criteria had a significantly higher prevalence of psychiatric and somatic disorders compared to the group met neither (36% v 6%, 22% v 10%, respectively). The overall prevalence of H pylori was 7%; prevalence increased with age from 3% at age < or = 10 to 10% for children >10 years. Children who met Rome II criteria had a significantly higher prevalence of H pylori infection than the reference group (18% v 4%). In a logistic regression model, all the study variables were included in the model specifying first the Rome II criteria group as the independent variable; psychiatric disorders, H pylori infection, and older age group were independent risk factors.

CONCLUSIONS

More than half the children suffering from recurrent abdominal pain met neither Apley's nor Rome II criteria. Children who meet Rome II criteria should be evaluated for psychiatric disorders and should be tested for H pylori infection. Despite the overall trend for a fall in the prevalence of H pylori infection among children in Japan, there are subpopulations of sick children where the prevalence of the infection is relatively high.

Torsion of a benign cyst arising from the tunica vaginalis testis

We describe a rare case of torsion of a benign cyst originating from the parietal layer of tunica vaginalis. This case presented with acute scrotum. Surgical exploration revealed a cyst arising from the parietal layer of tunica vaginalis of which the pedicle was twisted. When a cystic mass is detected in the scrotum of boys with acute scrotum, torsion of a cyst in the cavum tunica vaginalis testis should be considered.

Dihydropyrimidine dehydrogenase activity and mRNA expression in advanced gastric cancer analyzed in relation to effectiveness of preoperative 5-fluorouracil-based chemotherapy

Dihydroxypyrimidine dehydrogenase (DPD) is an enzyme involved in degradation and inactivation of 5-fluorouracil (5-FU). The amount of its expression in a tumor is thought to be a factor determining the response of the tumor to 5-FU therapy. We compared DPD activity and DPD mRNA expression in resected tumors between two groups of patients, i.e., a group of 14 patients with advanced gastric cancer who received preoperative chemotherapy (neoadjuvant chemotherapy; NAC) and surgery and a group of 24 patients with advanced gastric cancer who underwent surgery without preoperative chemotherapy. Tumor DPD activity was found to correlate well with tumor DPD mRNA expression. In the surgery alone group, DPD activity decreased significantly as the tumor stage advanced. This change was not observed in the NAC plus surgery group. Neither tumor depth (T factor) nor lymph node metastasis was found to correlate with DPD activity. Patients who responded to preoperative chemotherapy had lower DPD mRNA levels. Based on these results, we anticipate that measurement of DPD expression in clinical specimens may be clinically useful in managing advanced gastric cancer.

Nitric oxide induces a decrease in the mitochondrial membrane potential of peripheral blood lymphocytes, especially in natural killer cells

Increased levels of nitric oxide (NO) at an inflammatory site may affect the biological activity of lymphoid cells. To investigate the effects of NO on the immune system, we measured the mitochondrial membrane potential (delta psi m) of the peripheral blood lymphocytes (PBL) cultured with a chemical NO donor. PBL from healthy volunteers were cultured with NOC18, a NO-generating compound, at various concentrations. The delta psi m of the PBL was measured by flow-cytometry using 3,3-dihexyloxacarbocyanine iodide (DiOC6(3)). NOC18 induced a decrease in the delta psi m of the PBL in a dose-dependent fashion, induced an increase in the levels of reactive oxygen species (ROS), and caused these cells to undergo apoptosis. Dual-color staining of the delta psi m and lymphocyte surface markers demonstrated that CD3-CD56+ natural killer (NK) cells were responsive to NO. Trolox, a vitamin E analog, partially reversed the NO-induced decrease in the delta psi m of the PBL. We showed that the delta psi m of peripheral NK cells were decreased by NO, which suggests that abundant NO at an inflammatory site may impair NK cell function.

Recurrence of sigmoid colon carcinoma in the residual urethra after cystectomy

INTRODUCTION

We report a case of recurrence of sigmoid colon cancer in the residual urethra after cysto-prostato-sigmoidectomy.

METHODS/RESULTS

The patient successfully underwent urethrectomy and is currently tumor-free. To our knowledge, this is the first case of recurrence of a non-urothelial malignant tumor in the residual urethra.

Orthotopic ileal neobladder in male patients: functional outcomes of 66 cases

BACKGROUND

Orthotopic urinary diversion has become the preferred form of bladder reconstruction after cystectomy. We report on our experience with 66 male patients undergoing this procedure from November 1990 to February 1998.

METHODS

A neobladder was constructed using an ileal segment with a Hautmann type bladder. Complications were assessed and subdivided into early and late types. Voiding function was evaluated in terms of voiding pattern and continence. Median follow up was 19.5 (range 3.5-87.7) months.

RESULTS

There was one (1.5%) perioperative death. The most frequent pouch-related and unrelated early complications were persistent urine leak (7.6%) and prolonged ileus (16.7%), respectively, the majority of cases of which were managed conservatively. Analysis of late complications revealed 6.2% ureteroileal stenosis and 1.5% urethrointestinal stenosis rates, but no case of bladder stone formation. Of the 61 patients in whom voiding function was evaluable, 95.1% achieved excellent daytime continence, while only 67.2% had night-time continence. With regard to posture at voiding, 23 (37.7%) voided in a sitting position. Three of the patients (4.9%) were unable to void and required regular intermittent catheterization.

CONCLUSIONS

An orthotopic neobladder can be constructed with acceptable morbidity and excellent functional results. We believe that orthotopic urinary diversion offers an attractive alternative to a bladder substitute when cystectomy is required.

[Prevalence of upper urinary tract stones in Tajima, north Hyogo, Japan]

Toyooka Hospital is a central hospital in Tajima, a rural area in the northern part of Hyogo Prefecture. Because we possess the sole lithotripter in this area, almost all urolithiasis patients requiring treatment have been referred to our department. Based on the number of urolithiasis patients treated in our institution, we estimated the annual prevalence and incidence of upper urinary tract stones in the Tajima area. The mean annual prevalence of urolithiasis and incidence during the 1991-1993 period were 141 and 93 per 100,000, respectively. The male to female ratio was 2.0 to 1 in prevalence and 2.2 to 1.0 in incidence. Prevalence was highest in the sixties (245) and fifties (235), followed by the forties (205), seventies (162) and thirties (160). The incidence was highest in the fifties (169), followed by the forties (147), sixties (145) and thirties (118). In consideration of sex, the incidence was highest in males in the fifties and the forties. Of the patients with upper urinary calculi, 23.1% were treated by extracorporeal shock wave lithotripsy, while in 23.8% stones passed spontaneously and 50.9% were followed up without treatment. On stone analysis, calcium oxalate and/or calcium phosphate was present in 75.6%, uric acid in 16.4%, struvite and/or carbonate apatite in 5.6% and cystine in 1.4%. In summary, the prevalence and incidence of upper urinary tract calculi in the Tajima area were considerably higher than those in the nationwide survey on urolithiasis in Japan conducted in 1985.

A case of hydronephrosis caused by arteriosclerotic compression of the renal pelvis

We present the case of a 65-year-old woman with vascular compression of the renal pelvis, causing calyectasis. The diagnosis was a subtype of Fraley's syndrome. The cause of compression was concluded to be arteriosclerotic change of both the renal artery and the abdominal aorta.

[A case of transitional cell carcinoma and milk of calcium in a pyelocalyceal diverticulum]

A 66-year-old man presented with right flank pain and macroscopic hematuria. Abdominal radiographs and computed tomography revealed a right pyelocalyceal diverticulum with milk of calcium and a soft tissue mass inside it. Other examinations, including positive urine cytology and negative random bladder biopsies, suggested a malignant tumor of the pyelocalyceal diverticulum. The patient underwent right nephroureterectomy. Histopathological examination revealed grade 3 transitional cell carcinoma. This is the first case of transitional cell carcinoma and milk of calcium coexisting in the same pyelocalyceal diverticulum.

First-pass metabolism of peptide drugs in rat perfused liver

To elucidate the extent and mechanisms of the first-pass metabolism of peptide drugs in the liver after oral administration, a liver perfusion study was performed in rats using metkephamid, a stable analogue of methionine enkephalin, and thyrotropin-releasing hormone (TRH), as model peptides. The fraction of intact metkephamid recovered after single-pass constant perfusion through rat liver reached steady-state very quickly, and it was concluded that metkephamid was hydrolysed enzymatically at the surface of hepatocytes or endothelial cells of microvessels, or both, rather than being taken up by hepatocytes. The fraction of metkephamid recovered intact was approximately 40% under protein-free conditions but increased to 70-75% on addition of bovine serum albumin (BSA) to the perfusate. The fraction of metkephamid bound to BSA was approximately 50% under these conditions, implying that only the free fraction of metkephamid in the plasma was metabolized in the liver. Calculations based on the tube model showed that approximately 30-35% of metkephamid absorbed from the intestine undergoes first-pass metabolism before entering the systemic circulation in-vivo. In contrast, the fraction of TRH metabolized in the liver was less than 10%, indicating a remarkably low contribution of first-pass metabolism to the bioavailability of TRH. These results show that hepatic first-pass metabolism of metkephamid contributes to its low systemic bioavailability. After intestinal absorption free metkephamid is rapidly hydrolysed on the surface of hepatocytes or endothelial cells, rather than being taken up by hepatocytes. This information has important implications in the oral delivery of many kinds of peptide.

A new interpretation of salicylic acid transport across the lipid bilayer: implications of pH-dependent but not carrier-mediated absorption from the gastrointestinal tract

Transport of several monocarboxylic acids across the lipid bilayer was examined in liposomes consisting of egg yolk phosphatidylcholine and cholesterol. In the presence of inward proton gradient, salicylic acid (SA) was taken up rapidly by liposomes showing overshoot, saturation and competitive inhibition phenomena. These carrier-mediated like profiles of SA uptake can be explained by assuming a very high permeability through the liposomal membrane of protonated SA. Protonated SA in the extraliposomal solution (pH 5.8) was taken up by liposomes rapidly, followed by a redissociation to anion according to the intraliposomal pH (pH 7.5). The concentration gradient of protonated SA across the liposomal membrane is maintained until the intraliposomal pH decreased to the extraliposomal level, which facilitates the uptake of SA into liposomes. The permeability of the lipid bilayer to several compounds was estimated from the inhibitory effects of those compounds on SA uptake by liposomes. Good linear relationships were observed between their inhibitory effects on the liposomal uptake of SA and the permeability of the intestinal membrane to them determined both in vivo and in vitro. These results clearly indicate that the carrier-independent transport mechanism of monocarboxylic acids observed in liposomes significantly contributes to their absorption from the intestinal tract under physiological conditions.

Analysis of drug permeation across Caco-2 monolayer: implication for predicting in vivo drug absorption

PURPOSE

The aim of the present work is to characterize in vitro drug permeation processes across Caco-2 monolayer and to identify the advantages of this cultured cell system in predicting in vivo drug absorption after oral administration.

METHODS

The passive permeability of various drugs through Caco-2 monolayer was measured using Ussing-type chambers and compared with that of the isolated rat jejunum and colon. The in vivo drug permeability to the intestinal membrane was estimated by means of an intestinal perfusion study using the rat jejunum.

RESULTS

In Caco-2 monolayer, drug permeability increased with increasing drug lipophilicity and showed a good linear relationship with the in vivo permeability. In contrast, in the isolated jejunum and colon, the permeability of high lipophilic drugs was almost constant and, propranolol, a drug with the highest lipophilicity, hardly passed through the jejunal membrane in vitro. As a result, there was no significant relationship between in vitro and in vivo drug permeability in rat jejunum. However, the amount of drugs accumulated in the jejunal mucosa increased with increasing drug lipophilicity even under the in vitro condition.

CONCLUSIONS

The permeation and the accumulation studies suggested that the rate-limiting process of in vitro permeation of lipophilic drugs through the intestinal membrane differs from that of in vivo drug absorption. On the other hand, drug permeation through Caco-2 monolayer, which consists of an epithelial cell layer and a supporting filter, is essentially the same process as that of in vivo drug absorption. We concluded that the simple monolayer structure of a cultured cell system provides a distinct advantage in predicting in vivo drug absorption.

Quantitative evaluation of the gastrointestinal absorption of protein into the blood and lymph circulation

In order to investigate the fate of orally administered proteins, the absorption of ovalbumin (OVA) from the gastrointestinal tract into both the blood and lymph circulation was quantitatively evaluated. After oral administration, a significant amount of intact OVA was detected in both the plasma and the lymph fluid by means of a two-site enzyme immunoassay. The extent of absorption into the plasma, calculated from the area under the plasma concentration versus time curve of OVA after oral and intravenous administration, was only 0.007-0.008% of the dose. This value is extremely low compared to that after nasal administration, showing the stronger barrier function of the gastrointestinal tract against the invasion of macromolecular proteins into the body. The extent of absorption into the lymph was dose-dependent (0.0007-0.002% of dose), and a higher dose leads to a higher fraction of OVA absorbed into the lymph. Moreover, it was demonstrated that not only the small intestine but also the stomach can absorb OVA. OVA absorbed from the stomach was transferred almost exclusively to the blood circulation, which suggests different mechanisms and/or routes of absorption between the stomach and the small intestine. In order to improve the low oral absorption, OVA was incorporated in liposomes and administered orally. Although the effect of liposomes was not significant, it increased OVA absorption into both the plasma and lymph by about 2 to 3-fold. It was considered that the liposomes suppressed the enzymatic degradation of OVA and released it slowly in the gastrointestinal tract.

Intracorporeal lithotripsy with the Swiss Lithoclast

BACKGROUND

In addition to currently available modalities of intracorporeal lithotripsy (ultrasonic, electrohydraulic, and laser), a new ballistic lithotriptor known as the Swiss Lithoclast has recently gained attention. This study reports our experience with the Swiss Lithoclast in the endoscopic management of urinary calculi.

METHODS

A total of 51 patients with urinary calculi were treated with the Swiss Lithoclast; one patient with a renal calculus, 28 with ureteral calculi, and 22 with lower urinary tract (bladder, urethra and Kock pouch) calculi.

RESULTS

The Lithoclast successfully fragmented 94% of the calculi, independent of stone composition. Complete failure of fragmentation was not encountered. In six of the 10 upper ureteral calculi, stone fragments were pushed up into the calyces. Adjunctive extracorporeal shock wave lithotripsy for residual fragments was performed in six cases. The stone-free rate at one and three months was 84% and 88%, respectively. There were no intraoperative or long-term complications directly related to the use of this device.

CONCLUSION

The Swiss Lithoclast is a safe and effective means of intracorporeal lithotripsy. Although suitable for mid and lower ureteral stones, the device has a risk of stone push-up in patients with upper ureteral stones.

Epidural anesthesia modifies cardiovascular responses to severe hypoxia in dogs

Hypoxia is a critical and sometimes fatal complication of anesthesia. Since there is little information on the cardiovascular response to hypoxia during epidural anesthesia, we assessed the effects of epidural anesthesia on the cardiovascular response to hypoxia and on survival in dogs. We randomly assigned 36 mongrel dogs to one of three groups according to the anesthetic technique used: the thoracic group (n = 12) received thoracic epidural anesthesia plus general anesthesia, the thoracolumbar group (n = 12) received thoracolumbar epidural anesthesia plus general anesthesia, and the control group (n = 12) received general anesthesia alone. We monitored hemodynamics and plasma catecholamine concentrations and assessed survival in these groups during normocapnic hypoxia (FiO2, 0.09 for 120 min). During hypoxic challenge, PaCO2 and PaO2 values were similar in all groups. In both groups that received epidural anesthesia, heart rate, systolic and diastolic arterial pressures, and plasma epinephrine and norepinephrine concentrations were lower and arterial pH was greater than in the control group. There was no significant difference in survival among groups. Epidural anesthesia modified both the physiologic cardiovascular and catecholamine responses to hypoxia. Epidural anesthesia of the thoracic region did not appear to accelerate cardiac arrest, but it attenuated the development of metabolic acidosis during hypoxia.

Gastrointestinal absorption of peptide drug: quantitative evaluation of the degradation and the permeation of metkephamid in rat small intestine

The intestinal absorption of metkephamid (MKA), an analog of natural [Met]enkephalin, was investigated by means of vascular perfusion of the rat small intestine. Most of the MKA administered to the jejunal loop was degraded in the lumen by enzymatic hydrolysis, whereas only 0.3 to 1.2% of it was absorbed into the vascular flow. This means that enzymatic degradation is a major barrier against the intestinal absorption of MKA. The absorption of MKA was divided into two steps, degradation and permeation, and is expressed as clearance from the intestine. The degradation clearance (CLd) of MKA was 60- to 200-fold higher than the permeation clearance (CLp), indicating the rapid hydrolysis of MKA before absorption. The absorbed fraction of MKA increased with increasing luminal MKA concentration, mainly due to an increase in CLp rather than a decrease in CLd. MKA was degraded not only before absorption but also during permeation across the intestinal epithelium. Three kinds of enzyme inhibitors were co-administered with MKA into the intestinal loop. Puromycin, an aminopeptidase M inhibitor, markedly enhanced MKA absorption by both decreasing CLd and increasing CLp, indicating the predominant role of this enzyme in MKA degradation. Bestatin, another aminopeptidase M inhibitor, also effectively suppressed the degradation of MKA before absorption, whereas it only slightly increased CLp. It was further found that bestatin was less effective in inhibiting MKA hydrolysis during permeation. Thiorphan, an enkephalinase inhibitor, had no effect on MKA absorption.

Direct drug transport from the rat nasal cavity to the cerebrospinal fluid: the relation to the molecular weight of drugs

To clarify the relationship between the direct transport from the rat nasal cavity to the cerebrospinal fluid (CSF) and the molecular weight of the drug, the transport of fluorescein isothiocyanate-labelled dextran (FD) with various molecular weights was investigated. FDs (average molecular weights 4,400 (FD4); 9,400 (FD10); 18,900 (FD20); 40,500 Da (FD40)) were administered nasally or intravenously to rats, and the concentrations in the plasma and the CSF were measured and compared. None of the FDs were detected in the CSF after intravenous administration. However, FD4, FD10 and FD20 were observed to appear in the CSF after nasal administration, whereas the concentration in the plasma was much lower than that after intravenous administration. FD40 was not detected even after nasal administration. In addition, the concentration of these FDs in the CSF decreased with the increase in the molecular weight of FDs. These findings show that drugs with a molecular weight up to at least 20,000 Da can be directly transported from the nasal cavity to the CSF and that the transport of FDs to the CSF is dependent on their molecular weights.

Characterization of drug transport through tight-junctional pathway in Caco-2 monolayer: comparison with isolated rat jejunum and colon

Drug transport through the tight-junctional pathway in Caco-2 monolayer was studied by examining the relationship between its permeability to hydrophilic drugs and membrane conductance. Compared with the rat isolated jejunum or colon, Caco-2 monolayer displayed high electrical resistance and low conductance, as well as low permeability to sulfanilic acid and FITC-dextran (M.W. 4000). However, there was a linear relationship between the drug permeability and partial Cl- ion conductance for Caco-2 monolayer, rat jejunum and colon. Hence, the permeability to those drugs per unit of Cl- conductance is similar in the three membranes, suggesting that the size (radius) of the tight-junctional pathway in the three membranes is similar. In addition, when the electrical resistance of Caco-2 monolayer was reduced to the same level as that of the jejunum or colon by pretreatment with disodium ethylenediaminetetraacetate, its permeability to FITC-dextran became significantly higher than that of other membranes. Accordingly, the high resistance and the low permeability of Caco-2 monolayer compared with rat intestinal membrane may be due to structural differences between the membranes, rather than a difference in the tightness of the junction.