Cystatin C-based equation for estimating glomerular filtration rate in Japanese children and adolescents

Background

Renal inulin clearance is the gold standard for evaluation of kidney function, but is compromised by problems of collecting urine samples in children, especially those <6 years or with a bladder dysfunction. Therefore, we should utilize the serum cystatin C (cysC)-based estimated glomerular filtration rate (eGFR) for measuring serum cysC. The purpose of the present study is to determine the applicability of the new serum cysC-based eGFR in Japanese children and adolescents, including infants with chronic kidney disease (CKD), for evaluation of renal function.

Methods

Inulin clearance and standardized serum cysC level determined by the colloidal gold immunoassay were measured in 135 pediatric CKD patients between the ages of 1 month and 18 years with no underlying disease that affects renal function except CKD, to determine serum cysC-based eGFR in Japanese children and adolescents.

Results

We showed the inulin clearance by expression of 1/serum cysC in pediatric CKD patients, which resulted in the equation: inulin GFR (mL/min/1.73 m²) = 104.1 × 1/serum cysC (mg/L) ? 7.80. We also validated the cysC-based eGFR formula for Japanese adults. eGFR values obtained with the adult formula significantly underestimated GFR by approximately 8 % in children with CKD.

Conclusion

We determined the new cysC-based eGFR formula is useful for clinical screening of renal function in Japanese children and adolescents, including infants.     

Comparison of the Loss of Renal Function after Cold Ischemia Open Partial Nephrectomy,Warm Ischemia Laparoscopic Partial Nephrectomy and Laparoscopic Partial Nephrectomy Using Microwave Coagulation

Purpose

Nephron sparing surgery is an effective surgical option in patients with renal cell carcinoma. Laparoscopic partial nephrectomy involves clamping and unclamping techniques of the renal vasculature. This study compared the postoperative renal function of partial nephrectomy using an estimation of the glomerular filtration rate (eGFR) for a Japanese population in 3 procedures; open partial nephrectomy in cold ischemia (OPN), laparoscopic partial nephrectomy in warm ischemia (LPN), and microwave coagulation using laparoscopic partial nephrectomy without ischemia (MLPN).

Materials and Methods

A total of 57 patients underwent partial nephrectomy in Yokohama City University Hospital from July 2002 to July 2008. 18 of these patients underwent OPN, 17 patients received MLPN, and 22 patients had LPN. The renal function evaluation included eGFR, as recommended by The Japanese Society of Nephrology.

Results

There was no significant difference between the 3 groups in the reduction of eGFR. eGFR loss in the OPN group was significantly higher in patients that experienced over 20 minutes of ischemia time. eGFR loss in LPN group was significantly higher in patients that experienced over 30 minutes of ischemia time.

Conclusion

This study showed that all 3 procedures for small renal tumor resection were safe and effective for preserving postoperative renal function.Key Words: eGFR, Partial nephrectomy, Renal function, Laparoscopic partial nephrectomy     

Image-guided laparoscopic surgery in an open MRI operating theater

Background

The recent development of open magnetic resonance imaging (MRI) has provided an opportunity for the next stage of image-guided surgical and interventional procedures. The purpose of this study was to evaluate the feasibility of laparoscopic surgery under the pneumoperitoneum with the system of an open MRI operating theater.

Methods

Five patients underwent laparoscopic surgery with a real-time augmented reality navigation system that we previously developed in a horizontal-type 0.4-T open MRI operating theater.

Results

All procedures were performed in an open MRI operating theater. During the operations, the laparoscopic monitor clearly showed the augmented reality models of the intraperitoneal structures, such as the common bile ducts and the urinary bladder, as well as the proper positions of the prosthesis. The navigation frame rate was 8 frames per min. The mean fiducial registration error was 6.88 ± 6.18 mm in navigated cases. We were able to use magnetic resonance–incompatible surgical instruments out of the 5-Gs restriction area, as well as conventional laparoscopic surgery, and we developed a real-time augmented reality navigation system using open MRI.

Conclusions

Laparoscopic surgery with our real-time augmented reality navigation system in the open MRI operating theater is a feasible option.     

Optic nerve injury demonstrated by MRI with STIR sequences

We studied nine patients with optic nerve injury associated with closed head trauma by magnetic resonance imaging (MRI) with short inversion time inversion recovery (STIR) sequences on 11 occasions from 4 days to 14 years after the injury: three studies were within 17 days and eight over 4 months to 14 years. MRI revealed abnormal high signal in 10 of the 11 injured nerves. MRI 4 days after the injury showed no abnormality.     

How can we utilize livers from advanced aged donors for liver transplantation for hepatitis C?

Advanced age donors have inferior outcomes of liver transplantation for Hepatitis C (HCV). Aged donors grafts may be transplanted into young or low model for end stage liver disease (MELD) patients in order to offset the effect of donor age. However, it is not well understood how to utilize liver grafts from advanced aged donors for HCV patients. Using the UNOS database, we retrospectively studied 7508 HCV patients who underwent primary liver transplantation. Risk factors for graft failure and graft survival using advanced aged grafts (donor age ≥ 60 years) were analyzed by Cox hazards models, donor risk index (DRI) and organ patient index (OPI). Recipient's age did not affect on graft survival regardless of donor age. Advanced aged grafts had significant inferior survival compared to younger aged grafts regardless of MELD score (P < 0.0001). Risk factors of HCV patients receiving advanced aged grafts included donation after cardiac death (DCD, HR: 1.69) and recent hospitalization (HR: 1.43). Advanced aged grafts showed significant difference in graft survival of HCV patients with stratification of DRI and OPI. In conclusion, there was no offsetting effect by use of advanced aged grafts into younger or low MELD patients. Advanced aged grafts, especially DCD, should be judiciously used for HCV patients with low MELD score.     

Comparison of grey matter and metabolic reductions in frontotemporal dementia using FDG-PET and voxel-based morphometric MR studies

Purpose  The aim of this study was to investigate the regional differences between the morphologic and functional changes in the same patients with frontotemporal dementia (FTD) using statistical parametric mapping and voxel-based morphometry (VBM). Methods  Thirteen FTD patients (mean age, 64.9 years old; mean MMSE score, 17.7), 20 sex-matched Alzheimer’s disease (AD) patients (mean age, 65.0 years old; mean MMSE score, 17.5), and 20 normal volunteers (mean age, 65.2 years old; mean MMSE score, 29.0) underwent both [¹⁸F]FDG positron emission tomography and three-dimensional spoiled gradient echo MRI. Statistical parametric mapping was used to conduct a VBM analysis of the morphologic data, which were compared voxel by voxel with the results of a similar analysis of glucose metabolic data. Results  FTD patients showed decreased grey matter volume and decreased glucose metabolism in the frontal lobe and anterior temporal lobe. In addition, there was a clear asymmetry in grey matter volume in FTD patients by the VBM analysis while the glucose metabolic data showed little asymmetry. In AD patients, glucose metabolic reduction occurred in the bilateral posterior cingulate gyri and parietal lobules while grey matter density decreased the least in the same patients. Conclusion  In FTD, metabolic and morphologic changes occur in the bilateral frontal lobe and temporal lobe with a limited asymmetry whereas there was considerable discordance in the AD group.     

Clinical impact of the callosal angle in the diagnosis of idiopathic normal pressure hydrocephalus

The utility of measuring the corpus callosal angle (CA) for the diagnosis of idiopathic normal pressure hydrocephalus (INPH) was investigated. Three-dimensional magnetic resonance imaging (MRI) was performed in 34 INPH patients, 34 Alzheimer’s disease (AD) patients, and 34 normal control (NC) subjects. Measurement of the CA on the coronal MR images of the posterior commissure perpendicular to the anteroposterior commissure plane was performed for all subjects. The CA of the INPH group (mean ± SD, 66 ± 14°) was significantly smaller than those of the AD (104 ± 15°) and NC (112 ± 11°) groups. When using the threshold of the mean − 2SD value of the NC group (= 90°), an accuracy of 93%, sensitivity of 97%, and specificity of 88% were observed for discrimination of INPH from AD patients. Measuring the CA helps in differentiating INPH patients from AD and normally aged subjects.     

NPHS2 mutations in sporadic steroid-resistant nephrotic syndrome in Japanese children

Podocin is an integral membrane protein encoded by NPHS2, which is mapped to 1q25-31 and is exclusively expressed in glomerular podocytes. NPHS2 mutations are responsible for autosomal recessive familial steroid-resistant nephrotic syndrome (SRNS) with minor glomerular abnormalities or focal segmental glomerulosclerosis (FSGS), which is characterized by early childhood onset (age less than 6 years) and rapid progression to chronic renal insufficiency. This gene mutation is also responsible for an adolescent/adult onset form of autosomal recessive familial FSGS with heavy proteinuria. It has been demonstrated that sporadic SRNS and heavy proteinuria are also due to NPHS2 gene mutations. We isolated genomic DNA from 36 Japanese children with chronic renal insufficiency caused by SRNS or heavy proteinuria, and analyzed all eight exons and exon-intron boundaries of NPHS2 using the polymerase chain reaction and direct sequencing. The age at onset of disease was 3.9+/-0.5 years. There were 29 patients with SRNS and 7 with heavy proteinuria without nephrotic syndrome at the onset, but all patients developed chronic renal insufficiency 4.6+/-0.8 years after the onset. A new homozygous missense variant of NPHS2, G34E (G101A) in exon 1, was detected in 1 of 36 patients. However, this homozygous variant was also found in 1 of 44 normal controls, suggesting that the mutation is a polymorphism. Two silent variants (T954C and A1038G) in exon 8 of this gene were also identified in some of the patients and normal controls, indicating that the silent variants are also polymorphisms. There was no significant difference in the genotypic and allelic frequencies of T954C and A1038G polymorphisms between the patients and normal controls. In conclusion, NPHS2 gene mutations are not a major cause of chronic renal insufficiency caused by sporadic SRNS or heavy proteinuria in Japanese children.     

Prophylaxis of nausea and vomiting after laparoscopic cholecystectomy with ramosetron: randomised controlled trial.

OBJECTIVE: To evaluate the efficacy and safety of ramosetron (a 5-hydroxytryptamine type 3 receptor antagonist) for the prevention of nausea and vomiting after laparoscopic cholecystectomy. DESIGN: Prospective, randomised, double-blind, placebo-controlled study. SETTING: University and university-affiliated hospitals, Japan. SUBJECTS: 100 patients, 65 women and 35 men, who had laparoscopic cholecystectomy. INTERVENTIONS: Patients were given either placebo or ramosetron at 3 different doses (0.15 mg, 0.3 mg, 0.6 mg) intravenously at the completion of operation. The general anaesthetic technique and postoperative analgesia were standard. MAIN OUTCOME MEASURES: Vomiting and safety were assessed for 0 to 24 hours and 24 to 48 hours after anaesthesia. RESULTS: The number of patients who had a complete response (no nausea, no retching, no vomiting) during 0 to 24 hours after anaesthesia was 15/25 with placebo, 17/25 with ramosetron 0.15 mg, 23/25 with ramosetron 0.3 mg, and 23/25 with ramosetron 0.6 mg; The corresponding numbers from 24 to 48 hours were 16, 17, 23, and 23. No serious adverse events were observed in any of the groups. CONCLUSIONS: Ramosetron 0.3 mg was the minimum effective dose for preventing postoperative nausea and vomiting during 0 to 48 hours after anaesthesia in patients undergoing laparoscopic cholecystectomy.     

Inhaled olprinone improves contractility of fatigued canine diaphragm

Background. Diaphragmatic fatigue is implicated as a cause ofrespiratory failure. This study was undertaken to evaluate theeffects of inhaled olprinone, a newly developed phosphodiesteraseIII inhibitor, on the contractility of fatigued diaphragm indogs. Methods. Diaphragmatic fatigue was induced by intermittent supramaximalbilateral electrophrenic stimulation at a frequency of 20 Hzstimulation applied for 30 min. When fatigue was established,group I (n=8) received inhaled vehicle; group II (n=8) receivedinhaled olprinone 1 mg; group III (n=8) received inhaled olprinone2 mg. Diaphragmatic contractility was assessed by transdiaphragmaticpressure (Pdi, cm H₂O). Results. In the presence of fatigue, in each group, Pdi at low-frequency(20 Hz) stimulation decreased from baseline values (P<0.05),whereas Pdi at high-frequency (100 Hz) stimulation did not change.In groups II and III, during olprinone administration, Pdi atboth stimuli increased from fatigued values (20 Hz stimulation:group II (mean (SD)) 10.8 (1.0) to 12.5 (1.3), group III 10.9(1.7) to 15.0 (3.0); 100 Hz stimulation: group II 20.1 (1.9)to 22.6 (1.3), group III 20.6 (2.0) to 24.5 (2.0), P<0.05).The increase in Pdi was larger in group III than in group II(P<0.05). Conclusions. Inhaled olprinone produces a dose-dependent improvementin contractility of fatigued canine diaphragm. Br J Anaesth 2002; 88: 408–11