A model to evaluate toxic factors influencing islets during collagenase digestion: the role of serine protease inhibitor in the protection of islets

The recovery of all of the islets contained in a pancreas is the goal of islet isolation for transplantation. This study reveals an environment that injures the isolated islets during digestion and proposes a new model for optimal islet isolation. Islets were isolated from Wistar rat pancreases by stationary collagenase digestion while the digestion time was varied at 15, 30, 60, and 120 min. The digested pancreas and islets were analyzed histologically and adenosine nucleotides were measured. Overnight cultured islets (40 islets) were cocultured for 30 min with the supernatants obtained from pancreatic collagenase digestion at different digestion periods in order to assess the toxic environment. The peak yields of islets were obtained at 30 min of digestion. The histological study of digested pancreas showed that the exocrine cells lost their cellular integrity at 120 min of digestion, but the islet cells were left intact. Accordingly, the ATP levels of the pancreatic tissue decreased during the digestion period. The coculture experiment demonstrated that the islets cultured with the supernatants from the collagenase digestion showed digestion time-dependent disruption of the cellular integrity of islets in accordance with a rapid decrease of ATP levels in the islets. The addition of serine protease inhibitors into this coculture clearly showed protection of islets, which maintained high ATP levels in association with intact membrane integrity as assessed by AO/PI staining. Morphological deterioration of islets as well as a marked ATP decrease was evident in the entire digested pancreas as well as in islets cocultured in the supernatants from the collagenase digestion. Various factors toxic to the islets can therefore be analyzed in future experiments using this coculture model for obtaining a good yield of viable islets.     

Predominant role of FcgammaRIII in the induction of accelerated nephrotoxic glomerulonephritis

BACKGROUND: Nephrotoxic glomerulonephritis is induced by the administration of antibody against the glomerular basement membrane (GBM). We demonstrated previously that Fc receptors for immunoglobulin G (IgG) (FcgammaR) play crucial roles in the induction of accelerated nephrotoxic glomerulonephritis by using FcRgamma-deficient (-/-) mice. Since FcRgamma-/- mice lack the cell surface expression of two activating FcgammaRs, FcgammaRI and FcgammaRIII. The present study aims to identify the FcgammaR responsible for the induction of nephrotoxic glomerulonephritis. METHODS: Accelerated anti-GBM glomerulonephritis was induced in FcgammaRI-/-, FcgammaRIII-/-, and FcRgamma-/- mice by preimmunization with rabbit IgG followed by inoculation of rabbit anti-GBM antibody. Histologic analysis and immunostaining of renal sections were performed. RESULTS: FcgammaRI-/- mice as well as wild-type mice showed severe glomerulonephritis with hypernitremia by the administration of anti-GBM antibody. In contrast, FcgammaRIII-/- mice showed much milder renal involvement, similar to FcRgamma-/- mice. Histologically, FcgammaRI-/- mice showed intracapillary proliferation, glomerular thrombosis, and crescent formation, whereas FcgammaRIII-/- mice showed only glomerular hypercellular changes. The depositions of anti-GBM antibodies, autologous antibodies and complement C3 along the GBM were equally observed among all three FcR-/- mouse types by immunostaining. CONCLUSIONS: Accelerated nephrotoxic glomerulonephritis is induced predominantly through FcgammaRIII but not FcgammaRI.     

Transarterial Chemoembolization Using Cisplatin Powder in a Rabbit Model of Liver Cancer

The purpose of this study was to investigate the pharmacological advantages of transarterial chemoembolization (TACE) with cisplatin powder for hypervascular hepatic tumors in animal experiments. VX2 tumors were transplanted to the livers of nine rabbits. Cisplatin (1 mg/kg) was infused into the proper hepatic artery. In the cisplatin-HAI group, cisplatin solution was infused. In the cisplatin-GS-TACE group, after infusion of cisplatin solution, gelatin sponge particles were used for embolization. In the cisplatin-Lp-TACE group, after infusion of a cisplatin powder and lipiodol (10 mg/ml) suspension, gelatin sponge particles were used for embolization. Before and after administration, platinum concentrations in plasma were measured. Using liver specimens that were excised 60 min after infusion, platinum concentrations in tumorous and nontumorous liver tissues were measured. The mean platinum concentration in tumorous tissue was 0.88 μg/ml for the cisplatin-HAI group, 1.23 μg/ml for the cisplatin-GS-TACE group, and 12.65 μg/ml for the cisplatin-Lp-TACE group. The platinum concentration for the cisplatin-Lp-TACE group was significantly higher than that for the cisplatin-HAI group (p = 0.004) and the cisplatin-GS-TAE group (p = 0.004). The mean platinum concentration in nontumorous liver tissue was 0.98 μg/ml for the cisplatin-HAI group, 1.13 μg/ml for the cisplatin-GS-TACE group, and 1.09 μg/ml for the cisplatin-Lp-TACE group; no significant differences were seen. At both 5 and 10 min after infusion, the platinum concentrations for the cisplatin-Lp-TACE group were lower than those for the other two groups. The present results suggest that TACE using cisplatin powder/lipiodol suspension and gelatin sponge for hypervascular hepatic tumors has a number of pharmacological advantages. This material was presented at 2007 CIRSE.     

Comparison of plasma levels of mature adrenomedullin and natriuretic peptide as markers of cardiac function in hemodialysis patients with coronary artery disease

BACKGROUND: It has been suggested that, like ANP and BNP, high plasma levels of mature adrenomedullin (mAM) indirectly reflect the severity of heart failure or renal failure. However, the relationship between mAM levels and hemodynamics and cardiac function has not been examined in hemodialysis (HD) patients with coronary artery disease (CAD). The best marker, among mAM, ANP and BNP, for left-ventricular function in those patients is also unclear. PATIENTS AND METHODS: Plasma levels of mAM, total AM (tAM), ANP and BNP were determined before HD in chronic HD patients with CAD (group 1; n = 17) and were compared with those of HD patients without cardiac disease (group 2; n = 22). We examined their relationship to hemodynamics and cardiac function in group 1 using data obtained by cardiac catheterization. RESULTS: Plasma levels of ANP and BNP were significantly higher in group 1 than in group 2, but there was no significant difference in plasma levels of mAM and tAM between the two patient groups. Plasma levels of both mAM and tAM significantly correlated with right atrial pressure (RAP), and only plasma tAM levels correlated with pulmonary artery pressure (PAP) and pulmonary artery wedge pressure (PAWP). However, no correlations were found between levels of the two forms of AM and ejection fraction (EF). In contrast, plasma ANP and BNP levels significantly correlated with both PAP and PAWP, and also with EF, although they did not correlate with RAP. The correlation of PAP and PAWP with ANP and BNP levels was closer than that with tAM levels. The most significant correlation was between BNP levels and EF (r = -0.756, p < 0.0001). CONCLUSIONS: Our results suggest that the mAM level may be less useful than natriuretic peptide levels as a marker of cardiac function in HD patients with CAD, and that the BNP level might be the best indicator of left-ventricular function. In addition, cardiac disease such as CAD may have a minor impact on mAM levels compared to renal failure.     

Anesthetic management of four cases of craniotomy with alternate monitoring of motor and somatosensory evoked potentials

We experienced four cases of craniotomy in which motor evoked potential (MEP) and somatosensory evoked potential (SEP) were monitored alternately. Anesthesia was induced with propofol and fentanyl, and it was maintained with continuous infusion of propofol. Intermittently, propofol and fentanyl were administered as needed. Inhalation of 66% nitrous oxide did not prolong latency, but significantly reduced the amplitude of MEP. We could obtain the largest amplitude of MEP using five consecutive stimuli of which duration and frequency were 0.5 milliseconds and 500 Hz, respectively. Anesthetic management using propofol and fentanyl is useful for craniotomy with monitoring of MEP and SEP.     

Spontaneous fusion of isthmic spondylolisthesis after discitis: a case report

This is the first case report of a child with isthmic spondylolisthesis and discitis who had spontaneous fusion develop at an unstable level with relief of symptoms after nonoperative treatment. Although the blood culture was negative, the 14-year-old boy with Grade III isthmic spondylolisthesis of L5 was diagnosed with discitis at the L5-S1 level, based on clinical findings, elevated C-reactive protein, plain radiographs, and magnetic resonance imaging scans. The patient was treated with antibiotics for 19 weeks and bed rest for 4 weeks followed by immobilization in a hip spica cast for 8 weeks and a thoracolumbosacral orthosis for an additional 12 weeks. The lumbar back pain improved and there was a decrease in C-reactive protein to the normal range 3 weeks after onset. Forty months from onset, the patient was free from lumbar back or leg pain and his clinical neurologic examination was normal. Plain radiographs showed spontaneous fusion between L5 and the sacrum. This suggests that nonoperative treatment is acceptable even if discitis occurs at an unstable level.     

In situ graft-trimming method using polyester vascular prosthesis for inferior vena cava reconstruction after hepatectomy

Hepatectomy for secondary liver cancer that has invaded the inferior vena cava (IVC) can be the only way to achieve long-term survival. We describe a method for hepatectomy combined with partial IVC resection without venous bypass circulation and an in situ graft-trimming method to avoid graft size mismatch after reconstruction. We carried out left hepatectomy extended to segment 1 with partial IVC resection first. During resection and reconstruction of the IVC, it was clamped below the right hepatic vein and above the inferior right hepatic vein to maintain systemic circulation. The graft was trimmed in situ, after a half running suture of the graft was finished to ensure the correct size. Preservation of both inferior right hepatic vein and right hepatic vein helps to maintain systemic circulation during reconstruction of the IVC. The in situ graft-trimming method is an easy and safe method to ensure the correct graft size after IVC reconstruction.     

The distribution of vascular endothelial growth factor in human meniscus and a meniscal injury model

Background

The meniscus plays an important role in controlling the complex biomechanics of the knee. Meniscus injury is common in the knee joint. The perimeniscal capillary plexus supplies the outer meniscus, whereas the inner meniscus is composed of avascular tissue. Angiogenesis factors, such as vascular endothelial growth factor (VEGF), have important roles in promoting vascularization of various tissues. VEGF-mediated neovascularization is beneficial to the healing of injured tissues. However, the distribution and angiogenic role of VEGF remains unclear in the meniscus and injured meniscus. We hypothesized that VEGF could affect meniscus cells and modulate the meniscus healing process.

Predictors of improvement in low back pain after lumbar decompression surgery: Prospective study of 140 patients

Background

Lumbar decompression surgery is often used to treat neurological symptoms of the lower extremity as a result of lumbar disease. However, this method also leads to the improvement of the accompanying low back pain (LBP). We studied the extent of LBP improvement after lumbar decompression surgery without fusion and the associated preoperative factors.