Impact of recombinant human bone morphogenetic protein-2 on residual ridge resorption after tooth extraction: an experimental study in the rat

Residual ridge resorption begins following tooth extraction and continuously reduces alveolar bone volume, potentially creating a significant problem in dental implant treatment. In this study, the role of recombinant human bone morphogenetic protein-2 (rhBMP-2) in residual ridge resorption after tooth extraction was investigated. A polylactic acid/polyglycolic acid copolymer-coated gelatin sponge carrier was implanted with or without rhBMP-2 (1 microg) in the mesial root sockets after removal of maxillary first molars in male Wistar rats. Fine structural and histomorphologic analyses were conducted 3 to 84 days after implantation. Direct bone formation was first observed after 5 days on the rhBMP-2 side, which was transformed into cortical alveolar ridge with a smooth periosteal layer by 84 days, whereas the control side displayed slower healing. Bone histomorphometry revealed greater total bone area and increased bone height after 14, 28, 56, and 84 days on the rhBMP-2 side compared to the control side, and differences were significant after 14, 28, and 56 days. Larger numbers of proliferating cells and densely populated differentiating mesenchymal cells were observed on the rhBMP-2 side than on the control side in the early stage, and chondrogenesis was not observed. The findings indicate that rhBMP-2 may stimulate proliferation and differentiation of mesenchymal cells in the rat maxillary root socket to preserve cortical bone volume in the socket without any evidence of chondrogenesis.

Transcriptional activation of p21 by vitamin D(3) or vitamin K(2) leads to differentiation of p53-deficient MG-63 osteosarcoma cells

p21 (WAF1/CIP1) is a downstream effector of p53 and mediates growth arrest by inhibiting the action of G(1) cyclin-dependent kinases. However, it has been reported that the p21 expression was triggered by multiple differentiation-inducing agents by a p53-independent pathway. These agents induced expression of p21 by binding to specific DNA elements and modulating transcriptional initiation. We demonstrated that the gene encoding p21 was not only a vitamin D(3) target gene but also a vitamin K(2) target gene in the cells and that their differentiation was well related to the transcriptional activation of the p21 gene. Transient overexpression of p21, using adenovirus-driven p21 expression plasmid, in MG-63 cells in the absence of vitamins D(3) and K(2) resulted in their differentiation. The transcriptional activation of p21 by vitamin D(3) or vitamin K(2) in p53-deficient osteosarcoma cells demonstrated the p53-independent role of p21 in human osseous differentiation. HUM PATHOL 32:410-416.

The amide hydrogen of (-)-indolactam-V and benzolactam-V8's plays a critical role in protein kinase C binding and tumor-promoting activities

To investigate the role of the amide hydrogen of (-)-indolactam-V (1) and benzolactam-V8's on protein kinase C (PKC) binding and tumor promotion, 8-decylbenzolactone-V8 (6), a new lactone analogue of 8-decylbenzolactam-V8 (4), was synthesized from 2-nitrophenylpyruvic acid (7) in 11 steps. The PKC binding ability and tumor-promoting activities in vitro of 6 were much lower than those of 1 and 4, suggesting that the amide hydrogen of 1 and benzolactam-V8's plays a critical role in tumor promotion. However, it is noteworthy that 6 showed significant selectivity in the PKC isozyme surrogate binding.

The C4 hydroxyl group of phorbol esters is not necessary for protein kinase C binding

To investigate the role of the hydroxyl group at position 4 of the phorbol esters in protein kinase C (PKC) binding and function, 4beta-deoxy-phorbol-12,13-dibutyrate (4beta-deoxy-PDBu, 5a) and 4beta-deoxy-phorbol-13-acetate (6a) were synthesized from phorbol (1). The binding affinities of these 4beta-deoxy compounds (5a, 6a) to the 13 PKC isozyme C1 domains were quite similar to those of the corresponding 4beta-hydroxy compounds (4a, 4b), suggesting that the C4 hydroxyl group of phorbol esters is not necessary for PKC binding. Moreover, functional assays showed that 4beta-deoxy-PDBu (5a) exhibited biological activities (Epstein-Barr virus induction and superoxide generation) equally potent to those of PDBu (4a). These solution phase results differ from expectations based on the previously reported solid-phase structure of the complex of PKCdelta-C1B and phorbol-13-acetate (4b).

Manifestation of cutaneous polyarteritis nodosa during interferon therapy for chronic hepatitis C associated with primary biliary cirrhosis

Interferon alpha-2b was administered to a 50-year-old Japanese woman with chronic hepatitis C associated with primary biliary cirrhosis. Two months after the beginning of the interferon alpha-2b therapy a systemic nodular, erythematous rash developed. Histological analysis of the skin revealed typical features of necrotizing arteritis. Because there was no microhematuria, and no microaneurysms were detected on abdominal angiography, a diagnosis of cutaneous polyarteritis nodosa was made. A good outcome was achieved after interferon alpha-2b was discontinued and prednisolone was administered instead. The cutaneous polyarteritis nodosa in this patient is thus considered to have occurred as an adverse effect of interferon administration. To our knowledge, this is the first reported case of cutaneous polyarteritis nodosa which developed because of interferon therapy for chronic hepatitis C associated with primary biliary cirrhosis.

Dynamic localization and function of Bni1p at the sites of directed growth in Saccharomyces cerevisiae

Formin homology (FH) proteins are implicated in cell polarization and cytokinesis through actin organization. There are two FH proteins in the yeast Saccharomyces cerevisiae, Bni1p and Bnr1p. Bni1p physically interacts with Rho family small G proteins (Rho1p and Cdc42p), actin, two actin-binding proteins (profilin and Bud6p), and a polarity protein (Spa2p). Here we analyzed the in vivo localization of Bni1p by using a time-lapse imaging system and investigated the regulatory mechanisms of Bni1p localization and function in relation to these interacting proteins. Bni1p fused with green fluorescent protein localized to the sites of cell growth throughout the cell cycle. In a small-budded cell, Bni1p moved along the bud cortex. This dynamic localization of Bni1p coincided with the apparent site of bud growth. A bni1-disrupted cell showed a defect in directed growth to the pre-bud site and to the bud tip (apical growth), causing its abnormally spherical cell shape and thick bud neck. Bni1p localization at the bud tips was absolutely dependent on Cdc42p, largely dependent on Spa2p and actin filaments, and partly dependent on Bud6p, but scarcely dependent on polarized cortical actin patches or Rho1p. These results indicate that Bni1p regulates polarized growth within the bud through its unique and dynamic pattern of localization, dependent on multiple factors, including Cdc42p, Spa2p, Bud6p, and the actin cytoskeleton.

Effects of running exercise on the mandible and tibia of ovariectomized rats

To examine the effects of running exercise on the mandible and tibia of ovariectomized (OVX) rats, 26-week-old sham-operated (Sham) and OVX rats 1 week post-ovariectomy were subjected to non-exercise (Sham-Cont and OVX-Cont) and exercise (Sham-Exc and OVX-Exc) for 8 weeks. OVX induced a significant decrease in alkaline phosphatase (ALP) and an increase in tartrate-resistant acid phosphatase (TRAP) activity and a reduction of 17beta-estradiol in the serum. In OVX-Cont rats, histology and bone mineral density (BMD) showed bone loss in the proximal tibia, and histology, soft X-ray photographs and bone marrow area (BMA) revealed enlargement of the bone marrow cavity in the neck of the condylar process. In OVX-Exc rats, exercise significantly increased ALP activity, decreased TRAP activity and markedly elevated serum progesterone levels. Histology and BMD in the tibia and histology, X-ray photographs and BMA in the mandible were comparable to those in Sham rats. In Sham-Exc rats, unexpected decreases were observed in serum enzymes and hormones, but the histology and BMD in the tibia and histology, X-ray photographs and BMA in the mandible were very similar to those in Sham-Cont rats, suggesting a decrease of bone turnover with no change of bone mass in the tibia and mandible. We conclude that exercise has a beneficial effect not only on bone loss in the tibia, but also on differential changes in the neck of the condylar process, perhaps by increasing serum levels of progesterone in OVX rats.

Role of stromal cells in osteoclast differentiation in bone marrow

Bone marrow stromal cells have been considered to play an important role in osteoclast differentiation. However, the interaction of these cells in vivo has not been clearly demonstrated. To clarify this, we examined the distribution of alkaline phosphatase (ALPase) and tartrate-resistant acid phosphatase (TRAPase) activities as markers of osteoblastic and osteoclastic cells, respectively. Rat tibiae were fixed and embedded in Technovit 8100 or paraffin. ALPase and TRAPase activities were detected simultaneously on a plastic section by the azo-dye method. ALPase activity was detected on the plasma membranes of osteoblasts and some bone marrow fibroblastic stromal cells. These ALPase-positive cells were connected to each other by cytoplasmic processes, forming a cellular network in bone marrow. The ALPase activity of fibroblastic stromal cells tended to be stronger in those cells close to the bone surface than in the cells in the center of bone marrow. Reticular fibers in bone marrow were found to form a network. The ALPase-positive fibroblastic stromal cells may be reticular cells, because the localization of those cells was in accord with the localization of reticular fibers. The TRAPase-positive mononuclear cells and osteoclasts were mostly observed to be associated with the intensely ALPase-positive fibroblastic stromal cells. Immunoreactivity of osteoclast differentiation factor (ODF) was found in the fibroblastic stromal cells. These findings suggest that the network of ALPase-positive fibroblastic stromal cells in bone marrow serves as a guide for the migration of osteoclast precursor cells toward the bone surface, and may control the differentiation and activity of osteoclasts.

[Isolated abducens nerve palsy caused by the compression of the basilar artery: a case report]

Several pathological etiologies are responsible for abducens nerve palsy, but a neuro-vascular compression of the basilar artery has rarely been recognized as one of the causes. We performed magnetic resonance imaging of the brainstem of 71-year-old female patient with left abducens nerve palsy using constructive interference in the steady state (CISS) method, which allowed high-resolution T 2-weighted imaging and detection of the artery and nerves as high and low intensity area respectively. MRI with CISS revealed the compression of the abducens nerve by the basilar artery at the root exit zone. During the first examination her systolic blood pressure was over 180 mmHg, so we prescribed hypotensive agents until it to normalized. Her symptom of abducens nerve palsy improved after a few days. It is conceivable that compression of the basilar artery may have caused isolated abducens nerve palsy as disclosed by MRI with CISS.

Polyarteritis nodosa of the epididymis

We describe magnetic resonance imaging findings in a 37-year-old man with a rare entity of isolated polyarteritis nodosa of the epididymis, which correlated well with the histopathologic findings.

Multispectral analysis of the temporal evolution of cerebral ischemia in the rat brain

A major difficulty in staging and predicting ischemic brain injury by magnetic resonance (MR) imaging is the time-varying nature of the MR parameters within the ischemic lesion. A new multispectral (MS) approach is described to characterize cerebral ischemia in a time-independent fashion. MS analysis of five MR parameters (mean diffusivity, diffusion anisotropy, T2, proton density, and perfusion) was employed to characterize the progression of ischemic lesion in the rat brain following 60 minutes of transient focal ischemia. k-Means (KM) and fuzzy c-means (FCM) classification methods were employed to define the acute and subacute ischemic lesion. KM produced an estimate of lesion volume that was highly correlated with postmortem infarct volume, independent of the age of the lesion. Overall classification rates for KM exceeded FCM at acute and subacute time points as follows: KM, 90.5%, 94.4%, and 95. 9%; FCM, 82.4%, 90.6%, and 82.6% (for 45 minutes, 180 minutes, and 24-120 hours post MCAO groups). MS analysis also offers a formal method of combining diffusion and perfusion parameters to provide an estimate of the ischemic penumbra (KM classification rate = 70.3%). J. Magn. Reson. Imaging 2000;12:842-858.

Balloon-assisted coil placement in wide-necked cerebral aneurysms: preliminary clinical experience

Endovascular treatment of wide-necked cerebral aneurysms with Guglielmi detachable coils (GDCs) has been limited due to coil protrusion into the artery. Seven patients with wide-necked cerebral aneurysms were treated with GDCs with temporary balloon inflation for mechanical protection during coil placement. Transarterial embolization of the aneurysm with GDCs had failed due to coil protrusion into the parent artery. The use of simultaneous temporary balloon protection achieved more dense intra-aneurysmal coil packing, especially in the neck, without compromising the parent artery.

Synthesis and tumor-promoting activities of 12-Epi-phorbol-12,13-dibutyrate

12-Epi-phorbol-12,13-dibutyrate (1), the C12-epimer of the most frequently used phorbol ester probe, phorbol-12,13-dibutyrate (PDBu), has been synthesized from phorbol in 9 steps in order to investigate the structural requirements for tumor-promoting activity. Compound 1 showed about 100-fold weaker in vitro biological activities related to in vivo tumor promotion, Epstein-Barr virus early antigen (EBV-EA)-inducing ability, superoxide (O2-) generation-inducing ability, and binding to the protein kinase C (PKC) regulatory domain surrogate peptides. The results indicated that the beta-stereochemistry at position 12 of the phorbol skeleton is important for optimal activity. Binding selectivity to each PKC C1 domain of 1 was almost equal to that of PDBu.

14-3-3 protein family members have a regulatory role in retinoic acid-mediated induction of cytokeratins in F9 cells

We have found that the expression of five 14-3-3 protein isoforms is induced during the retinoic acid (RA)-mediated differentiation of mouse embryonal carcinoma F9 cells. The induced expression of the 14-3-3 proteins is presumed to have a role in enhancing the mitogen-activated protein kinase (MAPK) activity during RA-mediated F9 cell differentiation, because using genetically engineered budding yeast we showed that these isoforms enhanced the signaling in the MAPK cascade mainly through the interaction with Raf-1. Then we assessed the role of increased MAPK activity in F9 cell differentiation by interfering with signaling in the MAPK cascade in F9 cells. The exogenous expression of dominant-negative MEK1 efficiently abrogated RA-mediated induction of the cytokeratins EndoA and EndoC in the F9 cells. These results suggest that the 14-3-3 proteins play a role in the efficient induction of the cytokeratins during F9 cell differentiation through their signal enhancing activity in the MAPK cascade.

Endovascular treatment of basilar tip aneurysm associated with moyamoya disease--case report

A 58-year-old female was admitted unconscious to a local hospital. Computed tomography demonstrated subarachnoid hemorrhage. Cerebral angiography revealed evidence of moyamoya disease and a saccular aneurysm at the tip of the basilar artery. The patient was transferred to our hospital for embolization of the basilar tip aneurysm. Endovascular embolization was performed using Guglielmi detachable coils (GDCs), and the aneurysm was completely occluded with preservation of the parent artery. No change in the patient's neurological status was seen during and after the procedure. Endovascular treatment using GDCs appears to be particularly suitable for ruptured cerebral saccular aneurysms in patients with moyamoya disease.

Eruptive vellus hair cyst and epidermoid cyst in a patient with pachyonychia congenita

We report the first case of pachyonychia congenita (PC) associated with both eruptive vellus hair cyst (EVHC) and epidermoid cyst. The patient is a 12-year-old Japanese girl who presented with two natal teeth at birth. She had thickening and discoloration of the fingernails and toenails, plantar hyperkeratosis, palmar-plantar hyperhidrosis and multiple cutaneous cysts. Histologic examination revealed EVHC and epidermoid cyst.

Synthesis and PKC isozyme surrogate binding of indothiolactam-V, a new thioamide analogue of tumor promoting indolactam-V

To investigate the role of the amide group of (-)-indolactam-V (1) on PKC binding, we synthesized (-)-indothiolactam-V (2), a new thioamide analogue of 1, by microbial conversion using Streptomyces blastmyceticum. Compounds 2 and 1 showed similar binding affinities to conventional PKCs but 2 had lower affinities to novel PKCs, suggesting that novel PKCs recognize amide modifications more effectively than conventional PKCs.

A Ca(2+) channel blocker-like effect of dehydrocurdione on rodent intestinal and vascular smooth muscle

Effects of dehydrocurdione, a zedoary-derived sesquiterpene, on smooth muscle were investigated by recording the mechanical activity of intestines and aorta from guinea pigs and rats. Dehydrocurdione (0.1-3 mM) induced a sustained relaxation of rat duodenum and inhibited spontaneous motility. Dehydrocurdione (0.1-1 mM) inhibited the contractile response of guinea pig ileum induced by acetylcholine (0.01-10 microM), histamine (0.03-10 microM) and substance P (0.1-30 nM) in a non-competitive manner. Acetylcholine (0.5 microM) elicited a transient contraction followed by a sustained contraction of guinea pig ileum, and dehydrocurdione pretreatment inhibited the sustained component, which depends on Ca(2+) entry from the extracellular space. The high K(+)-induced contraction of rat aortic ring is reported to be blocked by Ca(2+) channel blockers, while the norepinephrine-induced contraction includes a Ca(2+) channel blocker-resistant component. Dehydrocurdione (1 mM) blocked the high K(+) (60 mM)-induced contraction of rat aortic ring by 81%, while it inhibited the norepinephrine (1 microM)-induced contraction by only 28%. Dehydrocurdione (1 mM) significantly reduced the high K(+)-stimulated increase in cytosolic Ca(2+) level of Fura-2-loaded mesenteric artery from rats. These results suggest that the inhibitory effects of dehydrocurdione on intestinal and vascular smooth muscle are mediated by blockade of Ca(2+) entry from the extracellular space.

A case of CD56+ cutaneous aleukaemic granulocytic sarcoma with myelodysplastic syndrome

We describe a 70-year-old man with cutaneous granulocytic sarcoma who presented with numerous cutaneous nodules but without any leukaemic involvement of the peripheral blood. The tumour cells were positive for lysozyme, peroxidase, CD11a, CD11c, CD33 and HLA-DR, and weakly positive for CD4 and CD14, suggesting granulocytic differentiation. The bone marrow at admission showed dysplasia of the erythrocytic and granulocytic lineage and complex chromosomal abnormalities in association with an increase in monocytes. The patient was diagnosed as having granulocytic sarcoma of monocytic lineage with concomitant myelodysplastic syndrome. In this case, tumour cells also expressed the neural cell adhesion molecule (CD56), which has been suggested as a possible risk factor for developing granulocytic sarcoma in acute myelogenous leukaemia.

Treatment of arteriovenous malformation of the brain--preliminary experience

With the availability of new techniques, such as intravascular embolisation and radiosurgery, the therapeutic approach to arteriovenous malformations (AVMs) of the brain has recently been modified. The present study reports the authors, experiences in treating AVMs over the past 13 years. Spetzler-Martin grading of AVMs was I and II in 19 cases, III in 12, IV in 5 and V in 1 case. Four therapeutic regimens were utilised: surgical resection alone, embolisation and resection, and radiosurgery alone or after surgical resection. Generally, for low-grade AVMs (Spetzler-Martin grades I, II and III), the therapeutic choice was surgical resection in 27 cases, in combination with pre-operative embolisation in two of these patients. Two cases received radiotherapy only and one case received radiosurgery after embolisation, while one case was treated conservatively. Of the five cases of grade IV, four required surgical treatment, whereas the fifth case was treated conservatively. Favourable results (good recovery and moderate disability) were obtained in 96% of the low-grade AVMs as compared with the high-grade AVMs (66%) that had a poor outcome (due to primary brain damage resulting from haemorrhage at the onset in three cases and due to postoperative re-bleeding in one case). This report summarises preliminary experience in treating intracranial AVMs by surgical resection, intravascular embolisation and radiotherapy. Good therapeutic results can be expected by combining these therapeutic modalities.

Role of inflammatory mediators in lipid A analogue (ONO-4007)-induced vascular permeability change in mouse skin

1. Endotoxin shock is accompanied by an increase in peripheral vascular permeability. It has been postulated that most biological activities of LPS are derived from lipid A moiety. Here we examined the effect of lipid A analogue ONO-4007 in increasing vascular permeability and the possible mediators in mouse skin by a dye leakage method. 2. Subcutaneous injection of ONO-4007 (1 - 2 mg site(-1)) induced a dose-dependent increase in vascular permeability which was evident after 120 min. 3. ONO-4007-induced dye leakage was significantly attenuated by pretreatments with anti-tumour necrosis factor-alpha (TNF-alpha) and anti-interleukin-1alpha (IL-1alpha) antibodies, but not with indomethacin (5 mg kg(-1)) or diphenhydramine (10 mg kg(-1)). ONO-4007-induced dye leakage was significantly inhibited by a pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME) (10 mg kg(-1)) but not with aminoguanidine (50 mg kg(-1)). In inducible nitric oxide synthase (iNOS)-deficient mice, ONO-4007 significantly increased the dye leakage, while ONO-4007 dilated rat thoracic aortic rings pre-contracted with phenylephrine, and the L-NAME pretreatment inhibited the dilation. 4. Thus, TNF-alpha, IL-1alpha and constitutive NOSs-derived nitric oxide but not prostaglandins or histamine play a role in ONO-4007-induced increase in vascular permeability. Although ONO-4007 mimics LPS in increasing vascular permeability, mechanisms of permeability change elicited by ONO-4007 were not identical to those of LPS.

Immunoreactivity to a monoclonal antibody (OS-3) is shared by osteoclasts and bicarbonate-secreting cells

OS-3, a monoclonal antibody raised against macrophagic cells derived from cultured rat glomeruli, reacts with the plasma membrane of various bicarbonate-secreting cells such as epithelial cells of the pancreatic excretory duct and type B intercalated cells of the kidney, suggesting that the antigenic molecule of OS-3 is involved in bicarbonate production and/or secretion. Since osteoclasts must vigorously extrude bicarbonate to maintain cytoplasmic pH in a physiologic range during proton secretion, we examined the localization of OS-3 immunoreactivity in the bone tissue to determine the involvement of the detected molecule in the transmembrane transport of bicarbonate in osteoclasts. The OS-3 selectively stained the basolateral plasma membrane of osteoclasts. Ultrastructurally, the immunoreactivity with OS-3 was associated with small cytoplasmic projections and microplicae of the basolateral plasma membrane. This finding suggests that osteoclasts express the molecule common to bicarbonate-secreting cells to utilize it for bicarbonate transport during bone resorption.

Localization of alkaline phosphatase and osteopontin during matrix mineralization in the developing cartilage of coccygeal vertebrae

We observed the manner in which alkaline phosphatase (ALPase) and osteopontin were localized in the cartilage and intramembranous bone of coccygeal vertebrae during matrix mineralization, shedding considerable light on the manner in which they develop. In the cartilage matrix of coccygeal vertebrae, we observed the localization of ALPase activity in the boundary of the proliferative and the hypertrophic zones. Granular nodules of mineralization were consistently found in the boundary of both zones, and increased in size when close to the hypertrophic zone. While osteopontin was rarely present in the early stages of mineralization, its localization along the margins of mineralized matrices in the hypertrophic zone was prominent. In contrast to cartilage, mineralized nodules in the intramembranous bone in the mid-portion of the vertebra displayed osteopontin-immunoreactivity, indicating its early synthesis and subsequent accumulation to early-stage mineralized nodules. When blood vessels, accompanied by osteoblastic and osteoclastic cell populations, invaded the cartilage, osteopontin was localized in the lower region of the hypertrophic zone, despite its maintaining the localization of ALPase and early-stage mineralization. Thus, our investigation demonstrated ALPase activity consistent with early-stage mineralization in the cartilage matrix. However, the fact that osteopontin-localization could not be pinpointed might account for its multifunctionality as concerns both the regulation of mineralization and the attachment of migrating osteogenic and osteoclastic cells to the mineralized matrix.