Transplantation of activated nucleus pulposus cells after cryopreservation: efficacy study in a canine disc degeneration model.

Transplantation of activated nucleus pulposus (NP) cells obtained by coculturing NP cells and bone marrow mesenchymal stromal cells having cell-to-cell contact has been shown to be effective in animal models and, more recently, in human clinical trials. If the NP cells can be cryopreserved, then autologous cell transplantation could be offered to patients as and when required. In a previous study, we confirmed that activated NP cells can be obtained by coculturing with mesenchymal cells after cryopreservation. However, the in vivo effects of cell transplantation therapy using activated NP cells prepared from cryopreserved cells are not known. In this in vivo canine model, we compared indicators of disc degeneration in animals that received transplanted activated normal NP cells, transplanted cryopreserved NP cells, and no cell transplantation after induction of disc degeneration. The intervertebral disc height on radiographs and T2-weighted magnetic resonance imaging were significantly higher in both cell transplantation groups compared with the degenerated disc group. Macroscopic and histological findings demonstrated attenuated disc degeneration in the two transplanted groups. Intense staining of proteoglycan and collagen type II was seen in green fluorescent protein-labelled transplanted cells, which suggested that the cells had survived and were functioning after transplantation. No significant differences were observed between the two transplanted groups. Transplanted activated cryopreserved NP cells induced a similar attenuation of intervertebral disc degeneration as that of conventionally activated NP cells. These findings suggest that the use of cryopreserved cells specific to a patient's condition has potential in transplantation therapy.

Stem cell applications in intervertebral disc repair.

There is increasing rise of interest in stem cell therapy, as it provides new options for treating a broad range of diseases. Several experimental methods are being explored for the use of stem cells in delaying or reversing the degenerative process of the intervertebral disc, a major cause of low back pain. In this article, we review the current strategies for stem cell applications in intervertebral disc repair and present three novel approaches. These are, first, the activation of nucleus pulposus cells by co-culture with mesenchymal stem cells for autologous disc cell reinsertion; second, the in vitro induction of nucleus pulposus-like or annulus fibrosus-like cells from mesenchymal stem cells; and third, the in vivo induction study by direct transplantation of mesenchymal stem cells to the intervertebral disc induced to degenerate experimentally. Although still untested, stem cell therapy may become a major option in the treatment of intervertebral disc degeneration.

Cross talk between Smad transcription factors and TNF-alpha in intervertebral disc degeneration.

The transforming growth factor-beta (TGF-beta) and the tumor necrosis factor-alpha (TNF-alpha) families are known to play important roles in intervertebral disc degeneration (IVD). However, molecular interactions between the TGF-beta and TNF-alpha signaling pathways have yet to be elucidated. The purpose of this study was to analyze the expression patterns of Smad transcription factor signaling associated with IVDs with aging and to examine the modulation of Smad signaling by TNF-alpha in IVD cells using SD rats. According to these experimental results, BMP signals in the TGF-beta family were more likely to be a key factor in IVD degeneration by aging, and it was predicted that besides the involvement of catabolic factors like MMPs and ADAMS-TS, there may be a decrease in expression of anabolic factors through cross talk of signaling between TNF-alpha and TGF-beta pathway in pathogenesis of disc degeneration.

TAB2, a novel adaptor protein, mediates activation of TAK1 MAPKKK by linking TAK1 to TRAF6 in the IL-1 signal transduction pathway.

The TAK1 MAPKKK mediates activation of JNK and NF-KB in the IL-1-activated signaling pathway. Here we report the identification of TAB2, a novel intermediate in the IL-1 pathway that functionally links TAK1 to TRAF6. Expression of TAB2 induces JNK and NF-kappaB activation, whereas a dominant-negative mutant TAB2 impairs their activation by IL-1. IL-1 stimulates translocation of TAB2 from the membrane to the cytosol where it mediates the IL-1-dependent association of TAK1 with TRAF6. These results define TAB2 as an adaptor linking TAK1 and TRAF6 and as a mediator of TAK1 activation in the IL-1 signaling pathway.

Pseudo-obstruction of the extrahepatic bile duct due to artifact from arterial pulsatile compression: a diagnostic pitfall of MR cholangiopancreatography.

PURPOSE: To evaluate the frequency of artifact from arterial pulsatile compression as the cause of pseudo-obstruction of the extrahepatic bile duct at magnetic resonance (MR) cholangiopancreatography (MRCP) and specify the causative vessels. MATERIALS AND METHODS: In 234 patients (102 men, 132 women; age range, 25-80 years), MRCP images obtained by using a single-shot turbo spin-echo sequence were reviewed to assess pseudo-obstruction of the extrahepatic bile duct caused by vascular compression. Dual-phase spiral computed tomography, contrast material-enhanced three-dimensional MR angiography, and/or digital subtraction angiography also were performed to determine the vessel that caused the pseudo-obstruction. RESULTS: Thirty-six pseudo-obstructions due to vascular compression were found in 33 (14%) patients. The common hepatic duct (27 [75%] sites) was the most common pseudo-obstruction site, followed by the left hepatic duct (four [11%] sites), proximal common bile duct (three [8%] sites), and right hepatic duct (two [6%] sites). The causative vessels were identified as the right hepatic artery at 24 (67%) sites; gastroduodenal artery, two (6%) sites; cystic artery, two (6%) sites; proper hepatic artery, one (3%) site; and an unspecified branch of the common hepatic artery, seven (19%) sites. CONCLUSION: At MRCP, pseudo-obstruction of the extrahepatic bile duct can be caused by pulsatile vascular compression of the hepatic and gastroduodenal arteries, and it should not be misdiagnosed as a bile duct tumor or biliary stone.

Dynamic subtraction contrast-enhanced MR angiography: technique, clinical applications, and pitfalls.

Rapid advances in techniques of contrast material-enhanced magnetic resonance (MR) angiography have enabled evaluation of the entire aorta and the main arteries. Dynamic subtraction MR angiography consists of first-pass imaging of long segments of arteries by using a three-dimensional fast field echo sequence with multiple rapid bolus injections of a small dose of gadopentetate dimeglumine. Subtraction enables clear demonstration of the enhanced vascular lumen by eliminating background signal. Improved temporal resolution and repeated sequences after gadopentetate dimeglumine administration allow demonstration of arteries and veins separately. Double subtraction postprocessing can be used to eliminate arterial enhancement in demonstration of the portal and systemic veins. Additional postprocessing can be used to demonstrate arteries in a single image in patients with aortic dissection or a prolonged circulation time. To optimize the examination, the pulse sequence, injection dose, injection rate, timing of the start of data acquisition, imaging time, breath holding, section thickness, and coil selection should be considered. This technique is flexible enough to be applied in a variety of clinical settings, including atherosclerotic occlusive disease, aneurysm of aortoiliac arteries, bypass graft, Takayasu arteritis, aortic dissection, antiphospholipid antibody syndrome, renal artery disease, pelvic vascular disease, and the portomesenteric venous system.

The kinase TAK1 can activate the NIK-I kappaB as well as the MAP kinase cascade in the IL-1 signalling pathway.

Interleukin-1 (IL-1) is a proinflammatory cytokine that has several effects in the inflammation process. When it binds to its cell-surface receptor, IL-1 initiates a signalling cascade that leads to activation of the transcription factor NF-kappaB and is relayed through the protein TRAF6 and a succession of kinase enzymes, including NF-kappaB-inducing kinase (NIK) and I kappaB kinases (IKKs). However, the molecular mechanism by which NIK is activated is not understood. Here we show that the MAPKK kinase TAK1 acts upstream of NIK in the IL-1-activated signalling pathway and that TAK1 associates with TRAF6 during IL-1 signalling. Stimulation of TAK1 causes activation of NF-kappaB, which is blocked by dominant-negative mutants of NIK, and an inactive TAK1 mutant prevents activation of NF-kappaB that is mediated by IL-1 but not by NIK. Activated TAK1 phosphorylates NIK, which stimulates IKK-alpha activity. Our results indicate that TAK1 links TRAF6 to the NIK-IKK cascade in the IL-1 signalling pathway.

[Clinical usefulness of fat suppression technique for MR cholangiopancreatography (MRCP)].

In order to obtain high quality of MRCP image, it is important to reduce the background signal intensity and increase the contrast of the pancreatobiliary ducts relative to surrounding fat tissue. The combination of long effective-TE and fat suppression technique including the short-TI inversion recovery and chemical-selective fat suppression enables to suppress the background signal intensity enough to obtain high quality MR cholangiopancreatogram. However, susceptibility artifacts from the metal, gastroduodenal gas, and vascular pulsation can be augmented by using the chemical-selective fat suppression technique, which may result in signal loss of the pancreatobiliary ducts. This potential diagnostic pitfalls can be avoided by interpreting the coronal source images obtained with long effective-TE and without fat suppression technique.

A human urinary protease inhibitor (ulinastatin) inhibits neutrophil extracellular release of elastase during cardiopulmonary bypass.

OBJECTIVES: To determine the benefits of a human urinary protease inhibitor (ulinastatin) on postoperative pulmonary dysfunction associated with neutrophil activation during cardiopulmonary bypass. DESIGN: A prospective, randomized, clinical study. SETTING: The study was performed at Keio University Hospital, Tokyo. PARTICIPANTS: Eighteen adult patients scheduled for primary cardiac surgery. INTERVENTIONS: The patients were randomly assigned either to the control group (n = 8) or to the group (n = 10) receiving ulinastatin (600,000 U in total). MEASUREMENTS AND MAIN RESULTS: Human neutrophil ability to release elastase in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) in vitro was measured before and after cardiopulmonary bypass, together with plasma levels of neutrophil elastase complex, interleukin-B, and C3a. Intrapulmonary shunt fraction was then calculated. Neutrophil elastase release in response to fMLP significantly increased in the control group, but remained unchanged in the ulinastatin group. In addition, ulinastatin minimized the increase of plasma neutrophil elastase, independently of the production of interleukin-B or C3a. Simultaneously, ulinastatin ameliorated the increase of intrapulmonary shunt, which was correlated with extracellular elastase release. CONCLUSIONS: Ulinastatin attenuated the elevation of fMLP-induced elastase release, which was associated with the deterioration of gas exchange during cardiopulmonary bypass. The administration of this agent has a potential to lessen the risk of postperfusion lung injury.

No. 302, a newly synthesized [pGlu4,Cyt6]AVP(4-9) analogue, prevents the disruption of avoidance behavior.

We investigated the effects of [pGlu4,Cyt6]AVP(4-9) fragments and its analogues on cycloheximide (CHX)-induced learning impairment in rats using the step-through-type passive avoidance test in rats. CHX (2.8 mg/kg, s.c.) significantly shortened the step-through latency in the retention trial. pGlu-Asn-Cys(Cys)-Pro-Arg-Gly-NH2 ([pGlu4, Cyt6]AVP(4-9); 10 ng/kg, s.c.), a major metabolite of arginine vasopressin, improved the CHX-induced learning impairment. Asn-Cys-Pro-Arg-OH ([Cys6]AVP(5-8); 1 ng/kg) corrected avoidance learning in the CHX-treated group, whereas neither Cys(Cys)-Pro-Arg-OH nor pGlu-Asn-Cys(Cys)-Pro-OH had any effect (1, 10 and 100 ng/kg, s.c.). pGlu-Asn-Ser-Pro-Arg-Gly-NH2 (No. 302), a newly synthesized [pGlu4,Cyt6]AVP(4-9) analogue, significantly prolonged the latency shortened by CHX at doses of 0.1, 1 and 10 ng/kg (s.c.). Asn-Ser-Pro-Arg-OH also improved the learning disruption induced by CHX, although the effective dose was 100 times higher than that of No. 302. The half-life of No. 302 in rat blood was about 5.5, 22 and 25 times longer than that of [pGlu4,Cyt6]AVP(4-9), [Cys6]AVP(5-8) and Asn-Ser-Pro-Arg-OH, respectively. These results suggest that [Cys6]AVP(5-8) is the minimal effective amino acid sequence in [pGlu4,Cyt6]AVP(4-9), and show that No. 302 is a potent, pharmacologically active peptide with high stability in the blood.

[Effect of isoflurane, enflurane and halothane on hemodynamics during the induction of anesthesia].

The effects of isoflurane(I), halothane(H) and enflurane(E) on hemodynamics of 36 patients (12, 11 and 13, respectively) were studied during the inhalation of 1.5 MAC of each anesthetics before the surgery. Mean arterial pressure(MAP), heart rate(HR), cardiac index(CI), systemic vascular resistance index(SVRI), and stroke volume index (SVI) were measured noninvasively using the automatic blood pressure manometer and the ultrasonic Doppler method (Accucom). MAP decreased with I, E and H, but a larger decrement was observed with E than with H. CI and SVI with H were less than with E. SVRI decreased with I and E but a significant difference was observed between E and H. Each value with I was between those with H and E. These results indicate that isoflurane causes the depression of blood pressure mostly by its effect to decrease afterload during the induction of anesthesia, although its depressing effect is less than that of enflurane.

[Clinical evaluation of the laryngeal mask airway using capnogram].

The laryngeal mask airway (LMA) was clinically evaluated using capnogram in patients who breathed spontaneously under the combination of general and spinal anesthesia. Using the LMA, the airway was maintained without jaw lift and no remarkable hemodynamic change was observed during its insertion and removal. Capnogram was useful to confirm the intact airway and to monitor the respiration. Respiratory depression was observed after thiopental administration and enflurane inhalation. The respiration recovered promptly following the increase of respiratory rate (RR) and tidal volume at first, and it made a further recovery following increase in RR. The use of the LMA under light inhalation anesthesia is hence a useful combination with regional anesthesia.

[Anesthetic management of the patient with a permanent pacemaker].

Anesthetic management of two patients with a permanent pacemaker is reported; patient no. 1 had the VVI mode pacemaker and patient no. 2 had the DDD mode pacemaker. In patient no. 1, the hypotensive response of the 'pacemaker syndrome' occurred during general anesthesia. Patient no. 2 had no anesthetic problems but careful attention should be paid to the DDD mode pacemaker, because the newer widely used dual lead systems (DDD) are more susceptible to electromagnetic interference. Anesthetists often encounter patients with pacemakers. Knowledge of pacemakers available of the increasingly wide range is necessary to ensure safe management of these patients, many of whom are frail and elderly.

[Effects of succinylcholine on serum levels of myoglobin and CK in children under halothane or enflurane anesthesia].

We studied the effects of succinylcholine (SCC) on serum levels of myoglobin (Mb) and CK in children under halothane or enflurane anesthesia. Forty-five children, aged 2 years 11 months to 12 years 6 months were subjected to this study. They were divided into four groups; the two groups were injected with SCC 1 mg.kg-1 intravenously to facilitate tracheal intubation and maintained with halothane (Group SH) or with enflurane (Group SE). The other two groups were intubated without the aid of SCC and maintained with halothane (Group H), or with enflurane (Group E). Mb was analyzed by an antibody radioimmunoassay technique and CK was analyzed by a modified Rosalki's method. While Mb increased in all four groups, the increase was pronounced in the SCC groups (60 min value of Group SH 2192 +/- 639 ng.ml-1, Group SE 1722 +/- 436 ng.ml-1, mean +/- SE), and the increase was significantly smaller in SCC free groups (Group H 40 +/- 12 ng.ml-1, Group E 43 +/- 9 ng.ml-1). The CK value increased only in the SCC groups to 174.1 +/- 32.8 IU.l-1 in Group SH, and to 193.6 +/- 35.7 IU.l-1 in Group SE at 60 min, respectively. These results indicate that increases in Mb and CK values were mainly induced by SCC injection and that SCC might play some roles in development of malignant hyperthermia.

[Comparison of intravenous buprenorphine or fentanyl and epidural buprenorphine for pain relief after upper abdominal surgery].

In three groups [(1) intravenous buprenorphine (0.1mg) or (2) fentanyl (100 micrograms.hr-1) and (3) epidural injection of buprenorphine (0.1mg diluted with 10ml normal saline)], we determined the effects of postoperative pain relief in patients after upper abdominal surgery. There are no differences in postoperative analgesia in the three groups, but respiratory depression was seen in some patients who had intravenous buprenorphine or fentanyl. We conclude that epidural injection of buprenorphine is a useful method for postoperative analgesia because of little adverse effect. As respiratory depression caused by buprenorphine was reversed with naloxone, it is not necessary to employ fentanyl instead of buprenorphine.