Requirement of nectin, but not cadherin, for formation of claudin-based tight junctions in annexin II-knockdown MDCK cells

Adherens junctions (AJs) and tight junctions (TJs) comprise a junctional complex which plays key roles not only in cell adhesion and polarization but also in regulation of cell movement and proliferation in epithelial cells. E-Cadherin and nectin are major cell-cell adhesion molecules (CAMs) at AJs, whereas claudin is a major CAM at TJs. We have shown that the cadherin-based cell-cell adhesion is not formed in MDCK cells in which annexin II, a Ca(2+)- and phospholipid-binding protein, is knocked down. Here, we found that TJs and the nectin-based cell-cell adhesions were formed in annexin II-knockdown cells. The formation of TJs in annexin II-knockdown MDCK cells required the nectin-based cell-cell adhesion and afadin, a nectin- and actin-filament-binding protein. In addition, it required the activation of Cdc42 and Rac small G proteins and subsequent reorganization of the IQGAP1-dependent actin cytoskeleton which were induced by the nectin-based cell-cell adhesion. These results indicate that the nectin-based cell-cell adhesion and afadin, but not the cadherin-based cell-cell adhesion, are necessary for the formation of TJs and that the signaling by nectin and the subsequent reorganization of the actin cytoskeleton are also necessary for the formation of TJs under certain conditions.

Endovascular treatment of experimental cerebral aneurysms using thermoreversible liquid embolic agents

SUMMARY

We have developed a new embolic agent, thermoreversible gelation polymer (TGP). This polymer is unique in that solidification occurs at body temperature. The utility of this new liquid embolic agent for the treatment of large experimental aneurysms was evaluated angiographically. TGP remains liquid at temperatures below the sol-gel transition temperature (TT) and becomes gelatinous above the TT. TGP can also be used to slowly deliver biologically active substances such as growth factors or engineered cells. In this study, TGP was mixed with radiopaque material without solvent. Bilateral common carotid arteries of swine (n=5) were used for surgical creation of lateral aneurysms, then 1 aneurysm in each animal was embolized using TGP without any protection device. The remaining untreated aneurysm in each animal was used as a control. All aneurysms were successfully embolized using TGP. No distal migration of TGP was observed when aneurysms were embolized without using protection devices. TGP can be safely used to embolize experimental aneurysms. Embolization of aneurysms with a protection device needs to be evaluated. Further modifications such as mechanical stability and use as a drug delivery system will be necessary prior to the clinical application of TGP.

Assessing Prognosis of Areas of Acute Cerebral Ischemia Using Perfusion CT

SUMMARY

Vascular recanalization by the vascular reconstruction method can dramatically improve ischemic symptoms in patients with acute cerebral ischemia. However, this treatment method is frequently associated with haemorrhagic complications. The indications for this therapeutic approach have been described in a number of studies in the literature. The present paper discusses the possibility of assessing the prognosis of ischemic areas using perfusion CT (PCT) by comparing the results obtained before and after thrombolytic therapy. Twenty-six patients underwent vascular reconstruction at our hospital between July 2002 and March 2004. Of these patients, six who underwent PCT before treatment and showed adequate recanalization following vascular reconstruction were included in the present study. PCT images were obtained using the first-pass bolus-tracking method with a 16-row multislice helical CT scanner. Areas of cerebral ischemia were evaluated by CT before and after vascular reconstruction. A region of interest was placed in the area showing low density in CT images before vascular reconstruction. The mean average CBF (mL/min/100 g), CBV (mL/100 g), and MTT (s) values were calculated in areas with and without cerebral infarction after vascular reconstruction. The %CBF, % CBV, and %MTT values relative to the normal side were evaluated with reference to the time until recanalization. Transarterial vascular reconstruction resulted in full recanalization in four patients and partial recanalization in two. The mean time from onset to recanalization was 284.7 +/- 63.27 minutes and was not longer than six hours in any patient. The patient prognosis results in terms of GOS were GR in two patients, MD in three patients, and SD in one patient. Based on comparison of the time after examination to recanalization, the %CBF showed a significant positive correlation in the salvaged area (Y = 47.321 + 2.491 x %CBF:R(2) = 0.792, p < 0.05). A significant correlation was not observed in %CBV, but %MTT showed a significant negative correlation (Y = 269.45 - 0.356 x %MTT:R(2) = 0.794, p < 0.05). The %CBF and %MTT results obtained by PCT performed before transarterial vascular reconstruction suggest that it may be possible to estimate the time before vascular reconstruction and the relationship with prognosis. These findings are expected to help ensure the appropriate application of vascular reconstruction and to provide useful information for developing optimal therapeutic protocols, thus reducing complications. In addition, because the results are based on the time after examination, the appropriate therapeutic approach can be determined even when the time of onset of ischemia is uncertain.

Stent Assisted Coil Embolization: the Treatment of Wide-necked, Dissecting, and Fusiform Aneurysms

SUMMARY

Stent assisted coil embolization is a useful therapeutic modality for wide-necked and geometrically difficult aneurysms, as the stent provide a buttress that allows for coil deposition while preventing coil haerniation into the parent vessel lumen, and placement of an endovascular stent within the parent artery across the aneurysm neck may divert the blood from the aneurysm inflow tract and promote intra-aneurysm stasis and thrombosis.We report herein a 3 patients treated with endovascular stent-assisted coil embolization for symptomatic or enlarging wide-necked, dissecting, and fusiform aneurysms of the carotid and vertebrobasilar arteries. One patient had intracranial mass effect, the second had subarachnoid haemorrhage, and the third had angiographic evidence of enlarging aneurysm. The aneurysm was located in the petrous segment of internal carotid artery in one patient and in the intracranial vertebral artery in the other two patients. For all patients, we used balloon expandable stent (such as GFX, S-670) in this technique. Complete obliteration of the aneurysms could be achieved in all cases, with preservation of distal circulation.

The use of mild hypothermia for patients with severe vasospasm: a preliminary report

The purpose of this study was to determine the effect of mild hypothermia on cerebral ischaemia due to severe vasospasm, which was refractory to medical and intravascular treatments and to assess the brain protection of this treatment in patients who underwent delayed aneurysm clipping after presenting with ischaemic neurological deficits. Mild hypothermia (32-34 degrees C of brain temperature) was employed in two groups: (1) Patients (Hunt and Kosnik grades I to II) who showed progressive neurological deficits due to vasospasm and did not respond to conventional therapy (Group 1) and (2) Patients who received delayed aneurysm clipping after presenting with ischaemic neurological deficits due to vasospasm (Group 2). Seven of 8 patients in both Groups showed a favorable outcome with mild hypothermia (good recovery in 5 and moderate disability in two patients). Mild hypothermia is considered to be effective on critical cerebral ischaemia due to vasospasm even after failure to response the conventional therapies and to provide brain protection in delayed aneurysm clipping.

Gene expression and accumulation of fibrillin-1, fibrillin-2, and tropoelastin in cultured periodontal fibroblasts

The elastic system fibers consist of three types--oxytalan, elaunin, and elastic fibers--differing in their relative microfibril and elastin contents. All three types are found in human gingiva, but human periodontal ligaments contain only elastin-free fibers. We examined cultured human gingival fibroblasts (HGF) and cultured human periodontal ligament fibroblasts (HPLF) to determine the gene expression of fibrillin-1 and fibrillin-2 (the major components of microfibrils) and of tropoelastin. In addition, we assessed the degree of accumulation of these proteins in the extracellular matrix. Northern blot analysis revealed that the level of expression of fibrillin-1 and fibrillin-2 was higher in HGF than in HPLF. However, examination of matrix samples from HGF and HPLF cell layers showed that there was no difference in fibrillin-1 accumulation, although fibrillin-2 accumulated to a much greater extent in the HGF-derived matrix. Tropoelastin was expressed only in and around HGF. These results show a correlation between gene expression and the accumulation of tropoelastin and fibrillin-2 in HGF.

Balloon-assisted guglielmi detachable coil placement in wide-necked internal carotid-ophthalmic aneurysms: a report of four cases

We present an endovascular technique for treating wide-necked ophthalmic aneurysms using Guglielmi detachable coils with simultaneous temporary balloon protection. Four illustrative cases of wide-necked ophthalmic aneurysms treated with Guglielmi detachable coils and a temporary balloon are presented. By blocking the parent artery with a non-detachable balloon, the coils could be safely placed in these aneurysms without herniation when the balloon was deflated. All patients exhibited embolic manifestations after the procedure, and the use of simultaneous temporary balloon protection allowed more dense intra-aneurysmal coil packing. Although this technique requires manipulation of a second microcatheter and balloon, which increases its technical difficulties and is a higher-risk procedure than the standard coil placement, it can be used for patients who are not candidates for surgery. Long-term follow-up is needed to determine the final outcome of aneurysms treated by this technique.

Tropoelastin expression by periodontal fibroblasts

Elastic system fibers are load-bearing proteins found in periodontal tissue. There are three types--oxytalan, elaunin, and elastic fibers--which differ in their relative microfibril and elastin contents. Oxytalan fibers are known to be distributed in the periodontal ligaments and gingiva, whereas elaunin and elastic fibers are present only in the gingiva. We examined gene expression and accumulation of tropoelastin in the cell-matrix layers of human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPLF) in vitro. HGF and HPLF were cultured in MEM containing 10% newborn calf serum for 8 wks. Northern blotting and RT-PCR analyses showed that only HGF expressed mRNA encoding tropoelastin. Western blotting analysis demonstrated 77-kDa protropoelastin and 68-kDa tropoelastin only in the cell-matrix layer of HGF cultured for 8 wks. These results suggest that the different tropoelastin expression patterns reflect the difference between HGF and HPLF phenotypes.

A lipid A analog ONO-4007 induces tolerance to plasma leakage in mice

OBJECTIVE

The effects of pretreatment with ONO-4007, a lipid A analog, on cutaneous plasma leakage induced by ONO-4007, lipopolysaccharide (LPS) and inflammatory mediators were investigated.

MATERIAL

Male ddY strain mice.

TREATMENT

Mice were pretreated with ONO-4007 (up to 6 mg/kg i.p.), 0-24 h prior to plasma leakage study.

METHODS

Plasma extravasation was determined by dye leakage.

RESULTS

Systemic ONO-4007 (6 mg/kg i. p.) pretreatment for 2 to 12 h inhibited plasma extravasation in the mouse skin elicited by ONO-4007 and LPS. The inhibition was dose-dependent. Plasma leakage induced by platelet-activating factor (PAF), histamine and 5-hydroxytryptamine (5-HT) was also inhibited by ONO-4007 pretreatment. Plasma corticosterone levels increased 2 and 4 h after systemic ONO-4007 (6 mg/kg) administration and returned to the control level 24 h later. Adrenalectomy and metyrapone but not propranolol reversed the inhibition by ONO-4007 pretreatment of LPS-induced plasma leakage.

CONCLUSIONS

A single injection of ONO-4007 in mice induced transient tolerance to plasma leakage elicited by LPS, ONO-4007 and inflammatory mediators. Endogenous corticosterone, at least in part, plays a role in the development of tolerance.

Diacylglycerol kinase gamma is one of the specific receptors of tumor-promoting phorbol esters

Diacylglycerol kinase (DGK) and protein kinase C (PKC) are two different enzyme families that interact with diacylglycerol. Both enzymes contain cysteine-rich C1 domains with a zinc finger-like structure. Most of the C1 domains of PKCs show strong phorbol-12,13-dibutyrate (PDBu) binding with nanomolar dissociation constants (K(d)'s). However, there has been no experimental evidence that phorbol esters bind to the C1 domains of DGKs. We focused on DGK gamma because its C1A domain has a high degree of sequence homology to those of PKCs, and because DGK gamma translocates from the cytoplasm to the plasma membrane following 12-O-tetradecanoylphorbol-13-acetate treatment similar to PKCs. Two C1 domains of DGK gamma (DGK gamma-C1A and DGK gamma-C1B) were synthesized and tested for their PDBu binding along with whole DGK gamma (Flag-DGK gamma) expressed in COS-7 cells. DGK gamma-C1A and Flag-DGK gamma showed strong PDBu binding affinity, while DGK gamma-C1B was completely inactive. Scatchard analysis of DGK gamma-C1A and Flag-DGK gamma gave K(d)'s of 3.1 and 4.4 nM, respectively, indicating that the major PDBu binding site of DGK gamma is C1A. This is the first evidence that DGK gamma is a specific receptor of tumor-promoting phorbol esters.

Electron microscopic observation of established chondrocytes derived from human intervertebral disc hernia (KTN-1) and role of macrophages in spontaneous regression of degenerated tissues

BACKGROUND CONTEXT

Biological and pathological cell processes during the degeneration of intervertebral discs are as yet poorly understood.

PURPOSE

An electron microscope was used to observe disc hernia degeneration at the cellular level as expressed in extruded tissue from a human intervertebral disc and in cultured chondrocytes. The mechanism of spontaneous regression was analyzed in order to investigate the effects of homologous macrophages, and the results of this analysis may be developed into a clinical therapy.

STUDY DESIGN/SETTING

Extruded tissue specimens excised during surgery on human intervertebral disc hernia and cultured chondrocytes isolated from the excised tissue were observed by means of electron microscopy. Extracellular matrix metalloproteinase-3 (MMP-3) and its antagonist, tissue inhibitor of metalloproteinases-1 (TIMP-1), were observed by means of immune electron microscopy. Macrophages confirmed by CD68 immunostaining were added to the chondrocyte culture and observed by means of electron microscopy.

PATIENT SAMPLE

All control subjects and patients gave written consent to the study.

OUTCOME MEASURES

KTN-1 was directly observed without culture, and nuclei degeneration, the development of chromatin granules, changes in the osmotic pressure of the nuclear membrane and rough-surfaced endoplasmic reticulum, and the development of fat droplets were observed.

METHODS

Tissues excised during surgery were divided, a part of the tissues were fixed in various fixatives for electron microscopy and immune electron microscopy analysis, and the other part was treated with collagenase. In addition, chondrocytes were isolated and cultured. Human peripheral blood mononuclear cells were separated using the Ficoll method. After culturing the cells, macrophages were collected, added to the chondrocyte culture, and observed under an electron microscope. CD68 positivity of the macrophages was confirmed by CD68 immunostaining.

RESULTS

Freshly isolated chondrocytes in the hernia's extruded region differed markedly from cultured chondrocytes. By means of immunoelectron microscopy, MMP-3 and TIMP-1 were localized at the endoplasmic reticulum of the cultured chondrocytes. Infiltration of macrophages among the chondrocytes was observed in the mixed culture.

CONCLUSIONS

The tissue extruded from the intervertebral disc showed obvious signs of degeneration, such as changes in osmotic pressure. Macrophages were observed to be the mechanism of spontaneous regression.

Growth pattern and expressions of cell cycle regulator proteins p53 and p21WAF1/CIP1 in early gastric carcinoma

BACKGROUND

The growth pattern of early gastric carcinoma, as based on a volumetric analysis, reflects the biologic characteristics of a tumor. The penetrating growth (Pen) type tumor has an unfavorable prognosis, compared with the case of a superficially spreading (Super) type. The wild-type of the p53 protein plays an important role in cell growth regulation and apoptosis. The p21 protein, which is encoded by the WAF1/CIP1 gene, is a downstream target effector of wild-type p53 protein, and these proteins act as tumor suppressors in a negative cell-cycle regulation.

METHODS

In 133 Japanese patients with early gastric carcinoma with submucosal invasion, expressions of p53 and p21 proteins were studied immunohistochemically, and the relation between growth pattern and expressions was analyzed.

RESULTS

Early gastric carcinomas were grouped into the superficially spreading (Super) type 40 (30.1%) cases, expansively penetrating growth (Pen-A) type 28 (21.1%), infiltratively penetrating growth (Pen-B) type 20 (15.0%), small mucosal type 35 (26.3%), and mixed type 10 (7.5%). The Pen-A type tumors were characterized by the highest incidence of p53 expression and loss of p21 expression, and the rate of p53-positive and/or p21-negative cases was 71.4%. There were significant differences in the incidence of the p53 expression (50.0% vs.25.0%), the loss of p21 expression (53.6% vs. 27.5%), and the 5-year survival rate (83.2 %vs. 97.2%) between the Pen-A type and the Super type.

CONCLUSIONS

Thus, deregulation of the cell cycle by p53 and p21 in this study was shown to play an important role in progression of Pen-A type early gastric carcinoma.

Immunohistochemical localization of membrane type 1-matrix metalloproteinase (MT1-MMP) in osteoclasts in vivo

Membrane type 1-matrix metalloproteinase (MT1-MMP) is capable of mediating proteolysis of extracellular matrix. The enzyme has been demonstrated in osteoclasts, in vitro. However, the precise localization in vivo, and therefore the function of the enzyme in osteoclasts, is still unclear. In this study, we immunohistochemically examined the localization of MT1-MMP in rat osteoclasts to clarify the role of MT1-MMP in osteoclastic bone resorption and bone turnover. The localization of MT1-MMP was visualized by the pre-embedding method using anti-MT1-MMP antibody and horseradish peroxidase (HRP) or gold-conjugated antibody. Immunoreactivity of anti-MT1-MMP was found in osteoclasts at the osteoclast-bone interface, but it was not uniform. Ultrastructurally, the immunoreactivity visualized by HRP was found in sealing zone. The plasma membrane at this site showed an irregular border and some invaginations. Immunoreactivity was also found on the surface of certain small vesicles in the cytoplasm. Enhanced silver granules were mainly associated with the sealing membrane. In this study, we demonstrated, for the first time, the localization of MT1-MMP in the sealing zone of osteoclast in vivo. Its distribution suggests that the enzyme modifies the bone surface to facilitate the migration and attachment of osteoclasts as well as scavenging the resorption lacunae.

Molded bone augmentation by a combination of barrier membrane and recombinant human bone morphogenetic protein-2

OBJECTIVES

To provide the histological background to a new method of local bone augmentation, we examined the events occurring beneath a barrier membrane applied with recombinant human bone morphogenetic protein-2 (rhBMP-2).

MATERIALS AND METHODS

The effects on bone augmentation of rhBMP-2, applied with a membrane mold (BMP-Memb), over surgically-induced bone defects in rat calvaria were examined histologically, and the results compared with those from application of rhBMP-2 (BMP) alone, or of a molded membrane (Memb) alone.

RESULTS

At postoperative week 2, the BMP group showed the most marked bone formation. However, the bone diminished in size by week 8. The Memb group showed slow but continuous bone formation by week 8. In the BMP-Memb group, bone filled the space in the mold at week 2, and this was maintained until week 8. Moreover, the soft tissue that had intervened between newly formed bone and the membrane in the Memb group was not evident in the BMP-Memb group, in which bone had formed directly on the membrane.

CONCLUSIONS

The results suggest that the combination of rhBMP-2 and barrier membrane has advantages in producing and maintaining bone in the intended shape by inducing osteoblasts directly on the inner surface of the membrane.

Transcatheter arterial chemoembolization therapy combined with percutaneous ethanol injection for unresectable large hepatocellular carcinoma: an evaluation of the local therapeutic effect and survival rate

BACKGROUND/AIMS

This study was undertaken to evaluate the effectiveness of combination therapy with transcatheter arterial chemoembolization followed by percutaneous ethanol injection in patients with unresectable large hepatocellular carcinoma by comparing the use of this combined regimen with transcatheter arterial chemoembolization alone.

METHODOLOGY

Six hundred and thirty-one consecutive patients with hepatocellular carcinoma lesions observed from Jan 1989 to Dec 1999 (11 years) at the Internal Medicine Department, Saga Prefectural Hospital Koseikan were retrospectively enrolled in the study. The series included 120 patients with large unresectable hepatocellular carcinoma lesions, the largest of which were greater than 3 cm in largest dimension. Fifty-two patients underwent a single transcatheter arterial chemoembolization followed by percutaneous ethanol injection, which were compared with 68 patients treated by transcatheter arterial chemoembolization alone. Both groups of patients with hepatocellular carcinoma did not differ regarding the base-line characteristics. The overall survival rates and recurrence ratio of initially treated lesions were compared in both groups.

RESULTS

On overall survival rates by the Kaplan-Meier method, three- and five-year survival in the transcatheter arterial chemoembolization and percutaneous ethanol injection group (59.0%, 32.1%) proved to be significantly longer than those in the transcatheter arterial chemoembolization group (27.1%, 17.0%). In addition, during the follow-up local recurrence in the combination group (23.1%) was significantly lower than that in the transcatheter arterial chemoembolization group (50.0%).

CONCLUSIONS

The combined treatment with transcatheter arterial chemoembolization and percutaneous ethanol injection proved to be more effective and safer. Furthermore, a lower incidence of local recurrence was observed than transcatheter arterial chemoembolization alone which resulted in an increased survival of the patients associated with unresectable large hepatocellular carcinoma lesions.

Protective effect of mild hypothermia on symptomatic vasospasm: a preliminary report

Mild hypothermia (32-34 degrees C of brain temperature) was used for brain protection in patients with progressive ischemic neurological deficits associated with severe cerebral vasospasm and who did not respond to medical treatment or intravascular angioplasty. Results showed that 2 of 3 patients in Hunt & Kosnik grade I to III and 2 patients who underwent delayed operation on day 5 and 9 each and had ischemic neurological deficits made good recovery with this treatment. Favourable outcome was obtained in 4 of 9 patients in grade IV and V. Mild hypothermia is thought to provide brain protection in critical ischemia due to severe cerebral vasospasm and can lengthen therapeutic time to employ angioplasty and intraarterial Papaverin infusion.

Inhibitory effects of cyclic AMP elevating agents on lipopolysaccharide (LPS)-induced microvascular permeability change in mouse skin

Anti-inflammatory effects of cyclic AMP elevating agents were examined in a mouse model of lipopolysaccharide (LPS)-induced microvascular permeability change. Vascular permeability on the back skin was measured by the local accumulation of Pontamine sky blue (PSB) after subcutaneous injection of LPS (400 microg site-1) from Salmonella typhimurium. Dye leakage in the skin was significantly increased 2 h after injection of LPS. This LPS-induced dye leakage was suppressed by phosphodiesterase inhibitors, including pentoxifylline (160 mg kg-1), milrinone (5 - 10 mg kg-1), rolipram (0.5 - 10 mg kg-1) and zaprinast (5 - 10 mg kg-1). The dye leakage was also inhibited by beta-adrenoceptor agonists, including isoproterenol (0.5 - 5 mg kg-1) and salbutamol (0.05 - 5 mg kg-1), an adenylate cyclase activator, forskolin (5 mg kg-1), and a cell permeable cyclic AMP analogue, 8-bromo-cyclic AMP (8-Br-cAMP, 10 mg kg-1). LPS caused a transient increase in serum TNF-alpha level peaking at 1 h after the injection. This increase in serum TNF-alpha was completely blocked by a pretreatment with pentoxifylline (160 mg kg-1), milrinone (5 mg kg-1), rolipram (1 mg kg-1), zaprinast (10 mg kg-1), salbutamol (0.5 mg kg-1), forskolin (1 mg kg-1) and 8-Br-cAMP (10 mg kg-1). LPS caused an increase in serum IL-1alpha level peaking at 3 h after injection. This increase in serum IL-1alpha was not significantly suppressed by the cyclic AMP elevating agents. Our study suggests that cyclic AMP elevating agents attenuate LPS-induced microvascular permeability change by suppressing TNF-alpha up regulation.

Toward the identification of selective modulators of protein kinase C (PKC) isozymes: establishment of a binding assay for PKC isozymes using synthetic C1 peptide receptors and identification of the critical residues involved in the phorbol ester binding

Conventional and novel protein kinase C (PKC) isozymes contain two cysteine-rich C1 domains (C1A and C1B), both of which are candidate phorbol-12,13-dibutyrate (PDBu) binding sites. We previously synthesized C1 peptides (of approximately 50 residues) corresponding to all PKC isozymes and measured their PDBu binding affinity. While many of these peptide receptors exhibited PDBu affinities comparable to the respective complete isozyme, some of the C1A peptides could not be used because they undergo temperature dependent inactivation. This problem was however eliminated by 4 degrees C incubation or elongation of the 50-mer C1 peptides at both N- and C-termini to increase their folding efficiency and stability. These findings enabled us to determine the K(d)'s of PDBu for all PKC C1 peptides (except for theta-C1A) and establish the value of these peptides as readily available, stable, and easily handled surrogates of the individual isozymes. The resultant C1 peptide receptor library can be used to screen for new ligands with PKC isozyme and importantly C1 domain selectivity. Most of the C1 peptide receptors showed strong PDBu binding affinities with K(d)'s in the nanomolar range (0.45-7.4 nM). Two peptides (delta-C1A and theta-C1A) bound PDBu over 100-fold less tightly. To identify the residues that contribute to this affinity difference, several mutants of delta-C1A and theta-C1A were synthesized. Both the G9K mutant of delta-C1A and the P9K mutant of theta-C1A showed K(d)'s of 2-3 nM. This approach provides a useful procedure to determine the role of each C1 domain of the PKC isozymes by point mutation.

[Chemotherapy for gliomas based on the expression levels of drug resistant genes]

Drug resistance, which often occurs during chemotherapy, is still a great obstacle to the success of human malignancy treatment. Among many possible mechanisms of drug resistance (biological, biochemical, kinetic or pharmacological), both typical and atypical multidrug-resistance (MDR) have been extensively studied. We picked up MDR-1, MXR, MRP1, MRP2, TopoII alpha, MGMT, and GST-pi as drug-resistant gene, based on experimental data and previous reports. Expression of these genes were measured in 14 malignant glioma specimens by reverse transcription polymerase chain reaction assay. We chose anticancer drugs for each patient, based on results of drug resistant gene expression to acquire good response to drugs. Though our follow-up periods are not long enough to analyze the results of our chemotherapy, 78% (7/9) of our glioma patients who were treated with our chemotherapy are free from tumor progression. The assays, which measure the expression of drug resistant genes, are necessary to allow rapid detection of the drug-sensitivity to chemotherapy in malignant glioma patients.

alpha-catenin-independent recruitment of ZO-1 to nectin-based cell-cell adhesion sites through afadin

ZO-1 is an actin filament (F-actin)-binding protein that localizes to tight junctions and connects claudin to the actin cytoskeleton in epithelial cells. In nonepithelial cells that have no tight junctions, ZO-1 localizes to adherens junctions (AJs) and may connect cadherin to the actin cytoskeleton indirectly through beta- and alpha-catenins as one of many F-actin-binding proteins. Nectin is an immunoglobulin-like adhesion molecule that localizes to AJs and is associated with the actin cytoskeleton through afadin, an F-actin-binding protein. Ponsin is an afadin- and vinculin-binding protein that also localizes to AJs. The nectin-afadin complex has a potency to recruit the E-cadherin-beta-catenin complex through alpha-catenin in a manner independent of ponsin. By the use of cadherin-deficient L cell lines stably expressing various components of the cadherin-catenin and nectin-afadin systems, and alpha-catenin-deficient F9 cell lines, we examined here whether nectin recruits ZO-1 to nectin-based cell-cell adhesion sites. Nectin showed a potency to recruit not only alpha-catenin but also ZO-1 to nectin-based cell-cell adhesion sites. This recruitment of ZO-1 was dependent on afadin but independent of alpha-catenin and ponsin. These results indicate that ZO-1 localizes to cadherin-based AJs through interactions not only with alpha-catenin but also with the nectin-afadin system.

The efficacy and safety of transvenous embolisation in the treatment of intracranial dural arteriovenous fistulas

To evaluate the role of transvenous embolisation including its efficacy and safety in the treatment of intracranial dural arteriovenous fistulas (DAVFs), we retrospectively analysed seven cases of intracranial DAVFs treated with transvenous embolisation in combination with arterial embolisation. Four DAVFs were in the cavernous sinus, two in the transverse-sigmoid sinus, and one in the inferior petrosal sinus. The transarterial and transvenous embolic agents included fibred platinum coils (FPC) and interlocking detachable coils (IDC). In all patients, the transarterial embolisation alone had failed to cure the DAVFs. After the combined transvenous embolisation, the anatomical cure was proven in five patients, and all patients were clinically cured. There were no complications in any patient. In conclusion, the transvenous embolisation is a useful and safe approach in the management of intracranial DAVFs.