Osteoprogenitor cells within skeletal muscle

The formation of ectopic bone within skeletal muscle is a widely observed phenomenon. However, the source of the osteoprogenitor cells responsible for ectopic bone formation remains unknown. This study was designed to test for osteogenic differentiation among cells isolated from skeletal muscle tissue. Different subpopulations of cells derived from an adult mouse skeletal muscle were tested for induction of alkaline phosphatase activity after exposure to bone morphogenetic protein-2 in vitro. A responsive subpopulation was identified, transduced with a retrovirus encoding for beta-galactosidase (Rv-lacZ) and an adenoviral construct encoding for one bone morphogenetic protein-2, and injected into the hindlimb of immune compromised (severe combined immunodeficient, or SCID) mice. The injected cells appeared to actively participate in the ectopic bone formation. The existence of lacZ-positive muscle-derived cells colocalized with osteocalcin-producing cells within lacunae of newly formed bone matrix suggests osteoblast and osteocyte differentiation. Although a specific cell was not isolated, these data support the contentions that osteoprogenitor cells reside within skeletal muscle and that muscle may represent a source other than bone marrow for the harvest of these cells.

Hepatocellular carcinoma treated with percutaneous radio-frequency ablation: usefulness of power Doppler US with a microbubble contrast agent in evaluating therapeutic response-preliminary results

PURPOSE

To evaluate the usefulness of power Doppler ultrasonography (US) with a microbubble contrast agent in assessing the therapeutic response of hepatocellular carcinomas (HCCs) treated with percutaneous radio-frequency (RF) ablation.

MATERIALS AND METHODS

Forty patients with 45 nodular HCC lesions 1.0-3.8 cm in diameter underwent power Doppler US before and after intravenous injection of a microbubble contrast agent. The same procedures were repeated after US-guided percutaneous RF ablation. The results of these studies were compared with those of three-phase helical computed tomography (CT) performed immediately after RF ablation.

RESULTS

Before RF ablation, nonenhanced power Doppler US demonstrated flow signals within tumor in 33 of 45 HCCs. After contrast agent administration, flow signals increased or newly appeared in all cases. After RF ablation, none of the ablated tumors showed intratumoral flow signals at nonenhanced power Doppler US, whereas six showed marginal intratumoral flow signals at contrast agent-enhanced power Doppler US. These six tumors were found to have small enhancing foci, suggestive of viable tumor, in corresponding areas at immediate follow-up CT. Additional RF ablation or transcatheter arterial chemoembolization was performed in these tumors.

CONCLUSION

The results of power Doppler US with a microbubble contrast agent in HCCs treated with RF ablation correlated well with those of contrast-enhanced CT. Preliminary data suggest that contrast-enhanced power Doppler US can be a promising noninvasive technique for assessing therapeutic response.

Abrogation of the p16-Rb pathway in Korean hepatocellular carcinomas

BACKGROUND/AIMS

The tumor suppressor gene p16 on human chromosome 9p21 encodes a specific inhibitor of the cyclin D-CDK4 complex which inactivates the Rb protein by hyperphosphorylation. Many reports show that p16 is inactivated in a variety of human cancers. We investigated whether abnormalities involving p16 and Rb are associated with hepatocellular carcinomas in Korea.

METHODOLOGY

We performed loss of heterozygosity analysis on 9 primary hepatocellular carcinomas using 7 microsatellite markers spanning human chromosome 9p. Reverse transcriptase-PCR, ribonuclease protection assay, and immunoblotting were used to examine the expression of p16 and Rb in 8 hepatocellular carcinoma cell lines, including 5 from Korean patients. Exons 1 and 2 of the p16 gene were sequenced.

RESULTS

We found a 33% loss of heterozygosity at the D9S171 locus (9p21 region) in the primary hepatocellular carcinomas. The p16 protein was not found in 4 out of 5 (80%) of the Korean cell lines. Among them, 2 cell lines lacked p16 protein and had the following point mutations in p16 exon 2: Asp125 to Asn and Arg58 to Ter. Two of the Korean cell lines and the SK-Hep-1 cells contained deletions in the p16 gene. All cell lines examined, except Hep 3B, expressed Rb protein, which in all cases was dominantly hyperphosphorylated (inactivated).

CONCLUSIONS

Our results suggest that p16 and Rb abnormalities are associated with hepatocellular carcinomas in the Korean population.

Mapping of a new target region of allelic loss at 21q22 in primary gastric cancers

To determine the minimal region of deletion on 21q22 in gastric cancer, we performed a high-density loss of heterozygosity (LOH) study with eight polymorphic microsatellite markers. Among the 43 tumors examined, 20 (50%) of 40 informative carcinomas showed LOH at one or more loci. The peak LOH frequency was identified at D21S1820 (34.2%) in 21q22.3. This data suggests that this locus might harbor a new tumor suppressor gene in an area <0.332 Mb in physical map distance defined by D21S1820 and D21S49. Thus, we speculate that trefoil factor family 1 (TFF1), located in this narrow region, might be the most probable candidate gene involved in gastric cancer carcinogenesis.

Hyaluronan: a multifunctional, megaDalton, stealth molecule

Hyaluronan has been implicated in biological processes such as cell adhesion, migration and proliferation. Traditionally, it was thought to be associated with the extracellular matrix, but, hyaluronan may also have unimagined roles inside the cell. Investigation of hyaluronan synthesis and degradation, the identification of new receptors and binding proteins, and the elucidation of hyaluronan-dependent signaling pathways are providing novel insights into the true biological functions of this fascinating molecule.

Rubella virus replication and links to teratogenicity

Rubella virus (RV) is the causative agent of the disease known more popularly as German measles. Rubella is predominantly a childhood disease and is endemic throughout the world. Natural infections of rubella occur only in humans and are generally mild. Complications of rubella infection, most commonly polyarthralgia in adult women, do exist; occasionally more serious sequelae occur. However, the primary public health concern of RV infection is its teratogenicity. RV infection of women during the first trimester of pregnancy can induce a spectrum of congenital defects in the newborn, known as congenital rubella syndrome (CRS). The development of vaccines and implementation of vaccination strategies have substantially reduced the incidence of disease and in turn of CRS in developed countries. The pathway whereby RV infection leads to teratogenesis has not been elucidated, but the cytopathology in infected fetal tissues suggests necrosis and/or apoptosis as well as inhibition of cell division of critical precursor cells involved in organogenesis. In cell culture, a number of unusual features of RV replication have been observed, including mitochondrial abnormalities, and disruption of the cytoskeleton; these manifestations are most probably linked and play some role in RV teratogenesis. Further understanding of the mechanism of RV teratogenesis will be brought about by the investigation of RV replication and virus-host interactions.

Characterization of a novel DNA polymorphism in the human CYP21 gene and application for DNA diagnosis of congenital adrenal hyperplasia

OBJECTIVES

Congenital adrenal hyperplasia (CAH) is a common endocrine disorder and CYP21 (21-OH, EC 1.14.99.10) deficiency is the most common cause of the disease. The presence of a pseudogene and a wide range of mutation types often makes DNA diagnosis difficult. Analysis of mutant alleles from patients with CAH identified a new DNA polymorphism in exon 10. To test the usefulness of this polymorphism, linkage analysis was performed using three RFLP's at both end of the CYP21 gene in patients and controls.

DESIGN AND PATIENTS

Genomic DNA was extracted from 21 unrelated patients and 39 unaffected individuals. Haplotyping analysis was performed for three RFLPs, MspI and Fnu4HI in intron 2 and a new SmaI RFLP in exon 10. All three polymorphic sites were characterized by DNA sequencing and usefulness of these RFLPs for DNA diagnosis was tested in patients' families.

MEASUREMENT

CAH patients were diagnosed by clinical symptoms and biochemical tests. Allele frequencies and heterozygosities were studied for three RFLP's in patients and controls using polymerase chain reaction (PCR).

RESULTS

A new SmaI RFLP showed a sequence difference as G or A at the nucleotide position 2694 in exon 10. Sequences at the MspI and Fnu4HI polymorphic sites were T or C at the nucleotide position 395 and 453, respectively. All of these RFLPs showed biallelic DNA polymorphisms and codominant segregation in family analysis. Heterozygosities were 0.31 for MspI, 0.48 for Fnu4HI and 0.44 for SmaI in normal individuals. There was no linkage disequilibrium for three RFLPs between patients and controls.

CONCLUSIONS

The SmaI RFLP can be useful for linkage analysis and DNA diagnosis in conjunction with RFLPs in intron 2 in CAH families because the polymorphic site is within the active gene at the 3' end. DNA sequencing results revealed that these RFLPs were created by gene conversions as with other mutations in the CYP21 gene.

p53 gene mutations in Bowen's disease in Koreans: clustering in exon 5 and multiple mutations

We analyzed the p53 protein expression and gene mutations to evaluate the role of ultraviolet radiation or other carcinogens, and possible racial differences in 17 samples from 12 Korean patients with Bowen's disease. A simple microdissection technique was used to collect the tumor cells selectively. p53 protein expression was found in eight of 17 (47%) samples. Abnormalities in polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis were observed in 16 (94%) samples. A total of 14 missense mutations were detected in eight (47%) samples; 11 were clustered in exon 5 and the remaining three were located in exon 8. UV-like mutations were seen in five of 14 (36%) mutations, but no CC to TT transitions, UV-fingerprint mutations were observed. Multiple mutations were present in two cases and double mutation in a single case. Each lesion in multiple Bowen's disease showed different mutations and was suggested to be of different clonal origins. TP53-loss of heterozygosity (LOH) was detected in four out of 15 (27%) informative samples. Clustering of mutations in exon 5 suggests the role of another carcinogen in Koreans or Asians other than the UVR. Microdissection would increase the detection rate of the p53 gene mutations and LOH not only in skin cancer but also in precancerous lesions.

Functional dichotomy of protein kinase C (PKC) in tumor necrosis factor-alpha (TNF-alpha ) signal transduction in L929 cells. Translocation and inactivation of PKC by TNF-alpha

Tumor necrosis factor-alpha (TNF-alpha) is capable of inducing a variety of biologic responses through multiple signaling pathways. Because of the potential role of protein kinase C (PKC) in apoptosis, we examined the effects and mechanisms of TNF-alpha on PKC regulation, specifically on PKC alpha. In L929 murine fibroblasts, TNF-alpha (0.5- 5 nm) caused potent inhibition of PKC alpha activity and induced translocation of PKC alpha from the cytosol to the membrane. Treatment of cells with TNF-alpha also induced dephosphorylation of PKC alpha as detected by a mobility shift on SDS-polyacrylamide gel and inhibition of PKC phosphorylation as probed by anti-phospho-PKC antibodies. Since PKC is activated directly by diacylglycerol and inactivated indirectly by ceramide, we next examined the roles of these lipid mediators in the regulation of PKC alpha. Addition of TNF-alpha led to accumulation of both ceramide and diacylglycerol. Fumonisin B(1), an inhibitor of ceramide synthase, and glutathione, an inhibitor of neutral sphingomyelinase, both reversed the effect of TNF-alpha on PKC alpha activity, suggesting that ceramide production is necessary for the action of TNF-alpha. The diacylglycerol mimic phorbol 12-myristate 13-acetate was sufficient to cause translocation of PKC alpha, but not the mobility shift. Okadaic acid at 2 nm, a potent protein phosphatase inhibitor, blocked the effects of TNF-alpha on PKC alpha activity, but not on PKC alpha translocation, thus demonstrating that dephosphorylation and translocation are independent processes. These results demonstrate that PKC alpha acts as a downstream target for TNF-alpha and that different lipid-mediated pathways in TNF-alpha signaling lead to opposing signals in the regulation of PKC alpha activity.

Two opposing effects of non-steroidal anti-inflammatory drugs on the expression of the inducible cyclooxygenase. Mediation through different signaling pathways

The efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) is considered to be a result of their inhibitory effect on cyclooxygenase (COX) activity. Here, we report that flufenamic acid shows two opposing effects on COX-2 expression; it induces COX-2 expression in the colon cancer cell line (HT-29) and macrophage cell line (RAW 264.7); conversely, it inhibits tumor necrosis factor alpha (TNFalpha)- or lipopolysaccharide (LPS)-induced COX-2 expression. This inhibition correlates with the suppression of TNFalpha- or LPS-induced NFkappaB activation by flufenamic acid. The inhibitor of extracellular signal-regulated protein kinase, p38, or NFkappaB does not affect the NSAID-induced COX-2 expression. These results suggest that the NSAID-induced COX-2 expression is not mediated through activation of NFkappaB and mitogen-activated protein kinases. An activator of peroxisome proliferator-activated receptor gamma, 15-deoxy-Delta(12,14)-prostaglandin J(2), also induces COX-2 expression and inhibits TNFalpha-induced NFkappaB activation and COX-2 expression. Flufenamic acid and 15-deoxy-Delta(12,14)-prostaglandin J(2) also inhibit LPS-induced expression of inducible form of nitric-oxide synthase and interleukin-1alpha in RAW 264.7 cells. Together, these results indicate that the NSAIDs inhibit mitogen-induced COX-2 expression while they induce COX-2 expression. Furthermore, the results suggest that the anti-inflammatory effects of flufenamic acid and some other NSAIDs are due to their inhibitory action on the mitogen-induced expression of COX-2 and downstream markers of inflammation in addition to their inhibitory effect on COX enzyme activity.

Enhanced guided bone regeneration by controlled tetracycline release from poly(L-lactide) barrier membranes

With the aim of providing effective periodontal therapeutic modality, drug-releasing membranes for guided tissue regeneration (GTR) were developed. As GTR membranes, biodegradable barrier membranes composed of porous poly(L-lactide) (PLLA) films cast on poly(glycolide) (PGA) meshes were fabricated using an in-air drying phase inversion technique. PLLA was dissolved in methylene chloride-ethylacetate mixtures, cast on knitted PGA mesh, and then air-dried. Tetracycline, which is used in periodontal therapy because of its antibacterial activity and tissue regenerating effects, including osteoblast chemotactic effect and anti-collagenolytic activity, was incorporated into the membranes by adding it to PLLA solutions. The guided bone regenerating potential of tetracycline-loaded membranes was evaluated using release kinetics both in vitro and in vivo, biodegradation tests, and cell attachment tests. Homogeneous pores were generated both at the surface and in a sublayer of the membranes. The release kinetics of tetracycline depended mainly upon the hydrophilicity of tetracycline and the porosity of the membrane. The release rate further could be controlled by loaded drug contents. The release of tetracycline was appropriate for maintaining anti-microbial activity and for its tissue-regenerating potential. The membranes retained a proper degradation property, maintaining their mechanical integrity for the barrier function for 4 weeks. Tetracycline-loaded membranes induced increased cell attachment levels compared with those of unloaded membranes. Tetracycline-loaded membranes markedly increased new bone formation in rat calvarial defects and induced bony reunion after 2 weeks of implantation. These results suggest that tetracycline-loaded PLLA membranes potentially enhance guided tissue regenerative efficacy.

Clonal isolation of muscle-derived cells capable of enhancing muscle regeneration and bone healing

Several recent studies suggest the isolation of stem cells in skeletal muscle, but the functional properties of these muscle-derived stem cells is still unclear. In the present study, we report the purification of muscle-derived stem cells from the mdx mouse, an animal model for Duchenne muscular dystrophy. We show that enrichment of desmin(+) cells using the preplate technique from mouse primary muscle cell culture also enriches a cell population expressing CD34 and Bcl-2. The CD34(+) cells and Bcl-2(+) cells were found to reside within the basal lamina, where satellite cells are normally found. Clonal isolation and characterization from this CD34(+)Bcl-2(+) enriched population yielded a putative muscle-derived stem cell, mc13, that is capable of differentiating into both myogenic and osteogenic lineage in vitro and in vivo. The mc13 cells are c-kit and CD45 negative and express: desmin, c-met and MNF, three markers expressed in early myogenic progenitors; Flk-1, a mouse homologue of KDR recently identified in humans as a key marker in hematopoietic cells with stem cell-like characteristics; and Sca-1, a marker for both skeletal muscle and hematopoietic stem cells. Intramuscular, and more importantly, intravenous injection of mc13 cells result in muscle regeneration and partial restoration of dystrophin in mdx mice. Transplantation of mc13 cells engineered to secrete osteogenic protein differentiate in osteogenic lineage and accelerate healing of a skull defect in SCID mice. Taken together, these results suggest the isolation of a population of muscle-derived stem cells capable of improving both muscle regeneration and bone healing.

[Tissue engineering and gene therapy of the musculoskeletal system with muscle cells]

AIM

Muscle-based somatic gene therapy is a novel way to alleviate a biochemical deficiency.

METHOD

Muscle-derived cells are very promising in the field of gene therapy and tissue engineering. First, most muscle tissue is accessible by injection. Second, muscle tissue consists of multinucleated, postmitotic myofibers, which enable a long-term expression of the transduced gene. Third, muscle tissue can be biopsied easily. It is available in abundance and the biopsy does not compromise the health and function of the patient. Finally, muscle tissue is highly vascularized, which makes systemic delivery feasible.

RESULTS

Muscle-derived cells can promote muscle healing and bone healing. Implanted cells maintain a long-term transgene expression of therapeutic proteins. Isolated, muscle-derived stem cells can differentiate in osteoblasts.

CONCLUSION

Based on these characteristics, we present four possible applications: inherited muscular diseases, muscle injury, bone healing, and intraarticular disorders.

Pulmonary tuberculosis: CT and pathologic correlation

Typical CT findings of active postprimary pulmonary tuberculosis include centrilobular nodules and branching linear structures (tree-in-bud appearance), lobular consolidation, cavitation, and bronchial wall thickening. The CT findings of inactive pulmonary tuberculosis include calcified nodules or consolidation, irregular linear opacity, parenchymal bands, and pericicatricial emphysema. The typical appearance of primary tuberculosis on CT scans is homogeneous, dense, well-defined segmental or lobar consolidation with enlargement of lymph nodes in the hilum or the mediastinum. Miliary nodules may be seen in primary and postprimary tuberculosis. On CT, tuberculomas appear as a nodule with surrounding satellite nodules and internal cavitation on CT. Atypical radiologic manifestations of tuberculosis, encountered in as many as one third of the cases of adult-onset tuberculosis, are single or multiple nodules or masses, basilar infiltrates, miliary tuberculosis with diffuse bilateral areas of ground-glass opacity, and reversible multiple cysts. Underlying histopathologic findings of typical and atypical CT findings of tuberculosis are caseating granulomas or pneumonia in the active phase and fibrosis and dystrophic calcification in the inactive phase.

Somatic mutations of the trefoil factor family 1 gene in gastric cancer

BACKGROUND & AIMS

There is increasing evidence that trefoil factor family 1 (TFF1) is a stabilizer of the mucous gel overlying the gastrointestinal mucosa that provides a physical barrier against various noxious agents. TFF1 knockout mice developed multiple gastric adenomas and carcinomas, suggesting that TFF1 is a gastric-specific tumor-suppressor gene.

METHODS

We analyzed the somatic mutations and loss of heterozygosity (LOH) of the TFF1 gene using an intragenic polymorphic marker in 61 gastric tumors. The expression pattern of TFF1 was also examined by immunohistochemistry.

RESULTS

We detected a total of 8 somatic mutations-1 (5.5%) of 18 adenomas and 7 (16.3%) of 43 carcinomas-that were all missense mutations confined to the loop I and loop II structure of TFF1. We detected LOH in 5 (1 in adenoma and 4 in cancer) of 30 (16.7%) informative gastric tumors with an intragenic polymorphic marker -2 base pairs (bp) upstream of the coding region of the TFF1 gene. Although 2 cases were noninformative, the 7 gastric cancers with mutation seemed to show the loss of the remaining allele except in 1 case, suggesting that TFF1 is a tumor-suppressor gene. We found loss of TFF1 expression in 44.2% of the gastric carcinomas, but there is no correlation between immunoreactivity and genetic alterations of the TFF1 gene.

CONCLUSIONS

These results indicate that genetic alterations of TFF1 may lead to gastric mucosal barrier defects and contribute to the pathogenesis of gastric cancer.

Ex vivo gene therapy to produce bone using different cell types

Gene therapy and tissue engineering promise to revolutionize orthopaedic surgery. This study comprehensively compares five different cell types in ex vivo gene therapy to produce bone. The cell types include a bone marrow stromal cell line, primary muscle derived cells, primary bone marrow stromal cells, primary articular chondrocytes, and primary fibroblasts. After transduction by an adenovirus encoding for bone morphogenetic protein-2, all of the cell types were capable of secreting bone morphogenetic protein-2. However, the bone marrow stromal cell line and muscle derived cells showed more responsiveness to recombinant human bone morphogenetic protein-2 than did the other cell types. In vivo injection of each of the cell populations transduced to secrete bone morphogenetic protein-2 resulted in bone formation. Radiographic and histologic analyses corroborated the in vitro data regarding bone morphogenetic protein-2 secretion and cellular osteocompetence. This study showed the feasibility of using primary bone marrow stromal cells, primary muscle derived cells, primary articular chondrocytes, primary fibroblasts, and an osteogenesis imperfecta stromal cell line in ex vivo gene therapy to produce bone. The study also showed the advantages and disadvantages inherent in using each cell type.

Low-dose, volumetric helical CT: image quality, radiation dose, and usefulness for evaluation of bronchiectasis

RATIONALE AND OBJECTIVES

The aim of our study was to assess the image quality, radiation dose, and clinical applicability of low-dose, volumetric helical CT in the evaluation of bronchiectasis.

METHODS

Volumetric helical CT scans (120 kVp, 3-mm collimation, pitch of 2, and reconstruction interval of 2 mm) were obtained through the thorax at four levels of tube current: 150, 100, 70, and 40 mA. There were a total of 12 patients who underwent CT scan either for suspected bronchiectasis or for lung cancer screening, with three patients allocated to each current level. Five radiologists assessed and compared image quality of the helical CT scans obtained at the various exposure levels. Radiation doses of helical CT performed with four different current settings and of high-resolution CT (120 kVp, 170 mA, 1-mm collimation, and 10-mm intervals) were measured. The diagnostic usefulness of the 40-mA helical CT images was compared with that of high-resolution CT by two observers in 52 patients with known or suspected airway diseases.

RESULTS

With helical CT, there was no significant difference in image quality among the four different levels of current (P > 0.05). Radiation doses associated with the 40-, 70-, 100-, and 150-mA helical techniques were 3.21 mGy (range, 3.02-3.57), 4.81 mGy (range, 3.89-5.93), 6.46 mGy (range, 6.01-7.31), and 10.4 mGy (range, 8.93-12.1), respectively, whereas that of high-resolution CT was 2.17 mGy (range, 1.90-2.67). Of 52 patients, 44.5 and 47 patients (the mean of positive interpretations by the five observers) were diagnosed with bronchiectasis at high-resolution and low-dose helical CT, respectively. Of 928 segments, bronchiectasis was seen in 152.5 segments on high-resolution CT and in 193.5 segments on helical CT. The interobserver agreement (k-values) was acceptable for both techniques.

CONCLUSIONS

With acceptable images and similar radiation dose, low-dose volumetric helical CT at 40 mA may offer more information than does high-resolution CT in the evaluation of bronchiectasis.

MR arthrography of the labral capsular ligamentous complex in the shoulder: imaging variations and pitfalls

OBJECTIVE

Using MR arthrography, we examined normal anatomy, anatomic variations, and pitfalls of imaging the labral capsular ligamentous complex in the asymptomatic shoulder.

SUBJECTS AND METHODS

We obtained 108 MR arthrograms of the glenohumeral joint in 95 asymptomatic volunteers with axial (108 shoulders) and oblique coronal (56 shoulders) images. We examined labral shape, patterns of capsular insertion, presence or absence of glenohumeral ligaments, and pitfalls of imaging. Our patients were men (auxiliary policemen) between 19 and 24 years old (mean age, 21 years).

RESULTS

The shapes of labra were triangular (anterior part, 64%; posterior part, 47%), round (17%; 33%), flat (2%; 17%), cleaved (11%; 1%), notched (3%; 0%), or absent (2%; 2%). Using the system of Mosely and Overgaard, the anterior capsular insertion was type 1 in 63% of shoulders, type 2 in 20%, and type 3 in 17%; the posterior capsular insertion was type 1 in 60% of shoulders, type 2 in 31%, and type 3 in 9%. The superior and inferior glenohumeral ligaments were present in 99% of shoulders, but the middle glenohumeral ligament was present in only 79%. We also detected many pitfalls of MR imaging in identifying findings such as the undercutting of the labrum by cartilage (32% of shoulders), prominent axillary folds (46%), sublabral holes (7%) or recesses (33%), Buford complexes (2%), and sulci between the biceps tendon and superior labrum (30%).

CONCLUSION

Knowledge of normal anatomy and anatomic variations of the labral complex is important for the examination of the shoulder with MR arthrography.

Synthesis and HIV-1 integrase inhibitory activities of caffeoylglucosides

Caffeoylglucosides, which have a glucose ring as a central linker, were synthesized from methyl D-glucosides, and their anti-HIV-1 activities were tested. Among them, four dicaffeoylglucosides (IC50 = 29.1+/-35.1 microM), 6a, 6b, 9b and 10b, showed HIV-1 integrase inhibitory activity as potent as L-chicoric acid.

Pharmacological characterization of (10bS)-1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline oxalate (YSL-3S) as a new alpha2-adrenoceptor antagonist

Alpha2-adrenoceptor antagonists, which can enhance synaptic norepinephrine levels by blocking feedback inhibition processes, are potentially useful in the treatment of disease states such as depression, memory impairment, impotence and sexual dysfunction. (10bS)-1,2,3,5,6,10b-Hexahydropyrrolo[2,1-a]isoquinoline oxalate (YSL-3S) was evaluated in several in vitro biological tests to establish its pharmacological profile of activities as an alpha2-adrenoceptor antagonist. Saturation binding assay revealed that [3H]rauwolscine bound to the alpha2-adrenoceptors with a Kd value of 6.3+/-0.5 nM and a Bmax value of 251+/-39 fmol/mg protein in rat cortical synaptic membranes. Competitive binding assay showed that YSL-3S inhibited the binding of [3H]rauwolscine (1 nM) in a concentration-dependent manner with a Ki value of 98.2+/-12.1 nM while it did not inhibit the binding of [3H]cytisine (1.25 nM) to neuronal nicotinic cholinergic receptors. The Ki values of yohimbine, clonidine and norepinephrine for [3H]rauwolscine binding were 15.8+/-1.0, 40.1+/-5.9 and 40.0+/-11.5 nM, respectively. In addition, the binding affinity of YSL-3S for alpha2-adrenoceptors was higher than that of its antipode and the racemic mixture. The functional activity of YSL-3S at the presynaptic alpha2-adrenoceptors was assessed using the prostatic portion of the rat vas deferens. Clonidine inhibited field-stimulated contractions of the vas deference in a dose-dependent manner. The presence of YSL-3S or yohimbine caused a parallel, rightward the dose-response curve of clonidine in a dose-dependent manner, indicating an antagonistic action at the presynaptic alpha2-adrenoceptors. The pA2 values of yohimbine and YSL-3S were 7.66+/-0.13 and 6.64+/-0.18, respectively. The results indicate that YSL-3S acts as a competitive antagonist at presynaptic alpha2-adrenoceptors with a potency approximately ten times lower than yohimbine, but is devoid of binding affinity for neuronal nicotinic cholinergic receptors.

Crystal structure of Escherichia coli CyaY protein reveals a previously unidentified fold for the evolutionarily conserved frataxin family

Friedreich ataxia is an autosomal recessive neurodegenerative disease caused by defects in the FRDA gene, which encodes a mitochondrial protein called frataxin. Frataxin is evolutionarily conserved, with homologs identified in mammals, worms, yeast, and bacteria. The CyaY proteins of gamma-purple bacteria are believed to be closely related to the ancestor of frataxin. In this study, we have determined the crystal structure of the CyaY protein from Escherichia coli at 1.4-A resolution. It reveals a protein fold consisting of a six-stranded antiparallel beta-sheet flanked on one side by two alpha-helices. This fold is likely to be shared by all members of the conserved frataxin family. This study also provides a framework for the interpretation of disease-associated mutations in frataxin and for understanding the possible functions of this protein family.

Allergic reaction to gemfibrozil manifesting as eosinophilic gastroenteritis

Eosinophilic gastroenteritis (EGE) is a rare condition of unknown etiology characterized by eosinophilic infiltration of the gastrointestinal (GI) tract. Previous associations with a drug or food allergy, allergic rhinitis, atopic dermatitis, and elevated IgE levels suggest an atopic predisposition in the pathogenesis of this disorder. Diagnostic criteria are GI symptoms, eosinophilic infiltration proven by biopsy of the GI tract, and absence of parasitic infection. We describe a case of EGE manifested as an allergy to gemfibrozil.

The temporal and spatial expressions of neuropeptide Y induced by seizure in the hippocampal complex of gerbil

Recent studies reported changes in neuropeptide Y (NPY) expression induced by seizures in the experimental epileptic models. However, there have been few reports of the alteration of NPY expression in hippocampal complexes of genetic epilepsy models. In the present study, we performed spatial and temporal analyses of NPY expression in the hippocampal complexes of the seizure-resistant (SR) and seizure-sensitive (SS) gerbils, one of the genetic models. In SR gerbils, most NPY(+) cells were located at the dentate hilus (DH) and the subiculum (SC). In the pre-seizure group of SS gerbils, neurons in the DH and SC were nearly devoid of NPY immunoreactivity. Interestingly, the acute NPY expressions were observed in these areas of the post-seizure group at 30 min, and its immunoreactivity was declined at 12 h after the onset of seizure. These findings suggest that in seizure, the deficiency of NPY in DH and SC may be one of the factors, and that the acute expression of NPY after seizure in these areas may be the compensatory response for reduction of seizure activity in this animal.

Controlled release of platelet-derived growth factor-BB from chondroitin sulfate-chitosan sponge for guided bone regeneration

Platelet-derived growth factor-BB (PDGF-BB) releasing porous chondroitin-4-sulfate (CS)-chitosan sponge was designed with an aim of controlling growth factor delivery in order to improve bone formation. Porous CS-chitosan sponge was fabricated by freeze drying and crosslinking aqueous CS-chitosan solution. PDGF-BB was incorporated into the CS-chitosan sponge by soaking CS-chitosan sponge into the PDGF-BB solution. CS-chitosan sponge retained a porous structure with a 150-200-microm pore diameter that was suitable for cellular migration and osteoid ingrowth. Release rate of PDGF-BB could be controlled by varying the composition of CS in the sponge or initial loading content of PDGF-BB. CS-chitosan sponge induced increased osteoblast migration and proliferation as compared with chitosan sponge alone. Furthermore, the release of PDGF-BB from CS-chitosan sponge significantly enhanced osteoblast proliferation. These results suggest that PDGF-BB-releasing CS-chitosan sponge may be beneficial to enhance bone cell adaptation and regenerative potential when applied in wound sites.