Sacroiliac fascial lipocele could be a neglected cause of lumbosacral pain: case study of percutaneous endoscopic treatment

The pathological entities commonly associated with lumbosacral pain are the intervertebral discs, facet joints or surrounding muscle. However, in the absence of diagnostic confirmation of the aforementioned structures, the diagnosis may become confusing and intractable. Sacroiliac fascial lipocele (SFL), namely, pannicular hernia, could be a neglected cause. First reported by Ficarra et al in 1952, it was highlighted by the formation of lipocele in the sacroiliac fascia. Mostly, it could be spontaneously eliminated under conservative therapy. However, for intractable pain, surgical intervention may be the only choice. We will first present a typical case of SFL which was treated by percutaneous endoscopic surgery. Ultimately, a satisfactory outcome was achieved and maintained at 12 months follow-up. It is important to distinguish SFL some cases with lumbosacral back pain. Detailed physical examination, superficial ultrasonography and diagnostic nerve block are extremely valuable for acquiring a precise diagnosis. Overall, when considering the clinical outcome of such cases and the foregoing benefits, percutaneous endoscopic treatment could be an efficacious alternative treatment for SFL-related lumboscral back pain.

Targeting BMP9-promoted human osteosarcoma growth by inactivation of notch signaling

Osteosarcoma (OS) is the most common primary malignancy of bone and is usually associated with poor prognosis due to its high incidence of metastasis and chemoresistance. Molecular pathogenesis of OS is poorly understood. We previously showed that OS cells are refractory to BMP9-induced osteogenesis and respond favorably to proliferation and tumor growth. Here we investigate if Notch signaling mediates the BMP9-promoted cell proliferation and tumor growth of human osteosarcoma (OS). We find that the expression of Notch1, Notch2, Notch3, DLL1, JAG1 and JAG2 is readily detected in most of the tested OS cell lines. BMP9-promoted OS cell proliferation, migration, and cell cycle S/G2 progression are effectively inhibited by a dominant-negative mutant of Notch1 (dnNotch1) or the γ-secretase inhibitor Compound E (ComE). Furthermore, BMP9-promoted tumor growth and osteolytic lesions in vivo are significantly inhibited by dnNotch1. BMP9 up-regulates the expression of Notch1, Notch3, DLL1, and JAG1 in OS cells. Accordingly, BMP9 stimulation induces a nuclear accumulation of NICD, which is blocked by ComE. Our results demonstrate that BMP9-promoted OS proliferation and tumor growth is at least in part mediated by Notch signaling, suggesting that osteogenic BMPs may function as upstream regulators of Notch signaling in OS tumorigenesis. Thus, pharmacologic intervention of Notch signaling may be explored as a new therapeutic strategy for human OS tumors.

Clinical Measurement of Intravertebral Pressure During Vertebroplasty and Kyphoplasty

Background: Vertebroplasty (VP) and kyphoplasty (KP) are emerging procedures for almost immediate pain relief when treating osteoporotic or osteolytic fractures. The main reported complication is polymethylmethacrylate (PMMA) leakage, which may lead to compression of neural structures or embolism. Different authors have proposed that intravertebral pressure (IP) is an important factor determining the risk for leakage, although so far only limited information has been gathered from clinical and experimental studies. There is also a lack of understanding of the IP during conventional interventions in VP and KP in the clinic. Objective: 1) To compare the intravertebral pressures of compressed vertebrae and adjacent normal vertebrae. 2) To measure the IP of compressed vertebrae during VP and KP. Setting: An interventional pain management practice, a medical center, major metropolitan city, in the People’s Republic of China. Methods: Thirty-five patients (with 40 compressed vertebrae and 35 adjacent normal vertebrae) were randomly allocated for intravertebral pressure measurements. Cannulas were placed bipedicularly into the posterior third of each vertebral body. Either PMMA or a balloon was injected into the vertebral body through the right cannula. A manometer was connected to the cannula in the left pedicle, and heparin was injected to verify the pressure measurement system. Results: The range (minimum-maximum), average IP, and the standard deviation of the compressed vertebrae were 0-39 mm Hg and 24.5 ±11.3 mm Hg; and that of adjacent normal vertebrae were 3-16 mm Hg, 7.3 ± 4.2 mm Hg. Furthermore, the average IP for Phase 1 (before PMMA injection) for VP was 23 ±11.9 mm Hg; the maximum IP recorded during injection was 169 ± 46.8 mm Hg and the IP for 10 minutes after injection was 33 ±9.4 mm Hg. Meanwhile, the highest IP recorded for KP patients was 142 ±39.6 mm Hg. The average IP for Phase 1 (before balloon inflation) was 24 ±12.7mmHg; Phase 2 (peak IP during the balloon inflation) was 63 ± 25.8 mm Hg; and Phase 3 (after balloon inflation/before PMMA injection) was , and 18 ± 10.8 mm Hg. The IP for 10 minutes after injection in KP patients was 36 ± 8.5 mm Hg. Limitations: The flow rate was manually controlled, which is in line with clinical routine, and was kept at approximately 0.1 mL/s. Because the speed of injection was controlled by hand, an exact injection rate could not be assured, leading to some inaccuracy when comparing the IP of VP and KP patients. Each patient was injected with a different PMMA volume. Because PMMA injection was performed to a satisfactory vertebral body filling and limited by any signs of extravasation, it was difficult to maintain a constant injection volume, unlike in vitro studies. Other factors such as the damage to the vertebral shell or the degree of osteoporosis might also have affected the intravertebral pressure. Conclusion: This study showed that the IP of compressed vertebrae was significantly higher than that of adjacent normal vertebrae. There was a significant increase in IP during the PMMA filling in VP and KP; the IP of compressed vertebrae was not significantly reduced by the balloon inflation in KP, and no statistically significant differences in IP were found during all common stages of PMMA filling in VP and KP. Key words: Vertebroplasty, kyphoplasty, intravertebral pressure, PMMA leakage.

Oridonin inhibits the proliferation of human osteosarcoma cells by suppressing Wnt/β-catenin signaling

It has been reported that oridonin (ORI) can inhibit proliferation and induce apoptosis in various types of cancer cell lines. However, the exact mechanism for this function remains unclear. In this study, we investigated the proliferation inhibitory effect of ORI on human osteosarcoma (OS) 143B cells and dissected the possible molecular mechanism(s) underlying this effect. We demonstrated that ORI can inhibit proliferation, induce apoptosis and arrest the cell cycle in 143B cells. Using luciferase reporter assay, we found that the Wnt/β-catenin signaling was inhibited in 143B cells by ORI. Accordingly, the total protein levels and nuclear translocation of β-catenin were reduced by ORI treatment. ORI increased glycogen synthase kinase 3β (GSK3β) activity and upregulated Dickkopf-1 (Dkk-1) expression. We found that Dkk-1 overexpression or β-catenin knockdown can potentiate the proliferation inhibitory effect of ORI in 143B cells, while β-catenin overexpression attenuated this effect. Using the xenograft tumor model of human OS, we demonstrated that ORI effectively inhibited the growth of tumors. Histological examination showed that ORI inhibited cancer cell proliferation, decreased the expression of PNCA and β-catenin. Our findings suggest that ORI can inhibit 143B OS cell proliferation by downregulating Wnt/β-catenin signal transduction, which may be mediated by upregulating the Dkk-1 expression and/or enhancing the function of GSK3β. Therefore, ORI can be potentially used as an effective adjuvant agent for the clinical management of OS.

The PTEN/PI3K/Akt and Wnt/β-catenin signaling pathways are involved in the inhibitory effect of resveratrol on human colon cancer cell proliferation

Colon cancer is one of the most common malignancies and the treatments for colon cancer have been developed substantially in the last decades, but there is still a great clinical need to explore new treatment regimens due to the undesirable prognosis. In this investigation, we demonstrated the anti-proliferative and apoptosis-inducing activities of resveratrol (Res) in human colon cancer cells, and the possible mechanisms underlying these effects. We used crystal violet staining, flow cytometry and western blotting to validate the anti-proliferative and apoptosis-inducing effects of Res on HCT116 cells. A xenograft tumor model was used to confirm the anti-proliferative effects of Res. We employed polymerase chain reaction, western blotting, recombinant adenovirus and luciferase reporter assay to explore the possible mechanism(s) of action. We found that Res inhibits significantly the proliferation and promotes apoptosis in HCT116 cells, as well as inhibits the xenograft tumor growth of colon cancer. Res upregulates the expression of phosphatase and tensin homolog (PTEN) and decreases the phosphorylation of Akt1/2. The exogenous expression of PTEN inhibits the PI3K/Akt signal and promotes the anti-proliferative effects of Res in HCT116 cells, while knockdown of PTEN increases PI3K/Akt signal but reduces the anti-proliferative function of Res. The protein and mRNA expression of β-catenin are all decreased by Res concentration-dependently. Thus, our findings strongly suggest that the anti-proliferative effects of Res in human colon cancer cells may be mediated by regulating separately the PTEN/PI3K/Akt and Wnt/β-catenin signaling.

BMP9 and COX-2 form an important regulatory loop in BMP9-induced osteogenic differentiation of mesenchymal stem cells

Mesenchymal stem cells (MSCs) can self-renew and differentiate into osteogenic, chondrogenic, adipogenic and myogenic lineages. It's reported that bone morphogenetic protein 9 (BMP9) is one of the most potent osteogenic BMPs to initiate the commitment of MSCs to osteoblast lineage. Cyclooxygenase-2 (COX-2) is critical for bone fracture healing and osteogenic differentiation in MSCs. However, the relationship between COX-2 and BMP9 in osteogenesis remains unknown. Herein, we investigate the role of COX-2 in BMP9-induced osteogenesis in MSCs. We demonstrate that COX-2 is up-regulated as a target of BMP9 in MSCs. Both COX-2 inhibitor (NS-398) and COX-2 knockdown siRNAs can effectively decrease alkaline phosphatase (ALP) activities induced by BMP9 in MSCs. NS-398 also down-regulates BMP9-induced expression of osteopontin and osteocalcin, so does the matrix mineralization. The in vivo studies indicate that knockdown of COX-2 attenuates BMP9-induced ectopic bone formation. In perinatal limb culture assay, NS-398 is shown to reduce the hypertropic chondrocyte zone and ossification induced by BMP9. Mechanistically, knockdown of COX-2 significantly inhibits the BMP9 up-regulated expression of Runx2 and Dlx-5 in MSCs, which can be rescued by exogenous expression of COX-2. Furthermore, knockdown of COX-2 apparently reduces BMP9 induced BMPR-Smad reporter activity, the phosphorylation of Smad1/5/8, and the expression of Smad6 and Smad7 in MSCs. NS-398 blocks the expression of BMP9 mediated by BMP9 recombinant adenovirus. Taken together, our findings suggest that COX-2 plays an important role in BMP9 induced osteogenic differentiation in MSCs; BMP9 and COX-2 may form an important regulatory loop to orchestrate the osteogenic differentiation in MSCs.

Clinical measurement of intravertebral pressure during vertebroplasty and kyphoplasty

BACKGROUND

Vertebroplasty (VP) and kyphoplasty (KP) are emerging procedures for almost immediate pain relief when treating osteoporotic or osteolytic fractures. The main reported complication is polymethylmethacrylate (PMMA) leakage, which may lead to compression of neural structures or embolism. Different authors have proposed that intravertebral pressure (IP) is an important factor determining the risk for leakage, although so far only limited information has been gathered from clinical and experimental studies. There is also a lack of understanding of the IP during conventional interventions in VP and KP in the clinic.

OBJECTIVE

(1) To compare the intravertebral pressures of compressed vertebrae and adjacent normal vertebrae. (2) To measure the IP of compressed vertebrae during VP and KP.

SETTING

An interventional pain management practice, a medical center, major metropolitan city, in the People's Republic of China.

METHODS

Thirty-five patients (with 40 compressed vertebrae and 35 adjacent normal vertebrae) were randomly allocated for intravertebral pressure measurements. Cannulas were placed bipedicularly into the posterior third of each vertebral body. Either PMMA or a balloon was injected into the vertebral body through the right cannula. A manometer was connected to the cannula in the left pedicle, and heparin was injected to verify the pressure measurement system.

RESULTS

The range (minimum-maximum), average IP, and the standard deviation of the compressed vertebrae were 0-39 mm Hg and 24.5 ±11.3 mm Hg; and that of adjacent normal vertebrae were 3-16 mm Hg, 7.3 ± 4.2 mm Hg. Furthermore, the average IP for Phase 1 (before PMMA injection) for VP was 23 ±11.9 mm Hg; the maximum IP recorded during injection was 169 ± 46.8 mm Hg and the IP for 10 minutes after injection was 33 ±9.4 mm Hg. Meanwhile, the highest IP recorded for KP patients was 142 ±39.6 mm Hg. The average IP for Phase 1 (before balloon inflation) was 24 ±12.7 mmHg; Phase 2 (peak IP during the balloon inflation) was 63 ± 25.8 mm Hg; and Phase 3 (after balloon inflation/before PMMA injection) was , and 18 ± 10.8 mm Hg. The IP for 10 minutes after injection in KP patients was 36 ± 8.5 mm Hg.

LIMITATIONS

The flow rate was manually controlled, which is in line with clinical routine, and was kept at approximately 0.1 mL/s. Because the speed of injection was controlled by hand, an exact injection rate could not be assured, leading to some inaccuracy when comparing the IP of VP and KP patients. Each patient was injected with a different PMMA volume. Because PMMA injection was performed to a satisfactory vertebral body filling and limited by any signs of extravasation, it was difficult to maintain a constant injection volume, unlike in vitro studies. Other factors such as the damage to the vertebral shell or the degree of osteoporosis might also have affected the intravertebral pressure.

CONCLUSION

This study showed that the IP of compressed vertebrae was significantly higher than that of adjacent normal vertebrae. There was a significant increase in IP during the PMMA filling in VP and KP; the IP of compressed vertebrae was not significantly reduced by the balloon inflation in KP, and no statistically significant differences in IP were found during all common stages of PMMA filling in VP and KP.

Characterization of chondrocyte scaffold carriers for cell-based gene therapy in articular cartilage repair

Articular cartilage lesions in the knee are common injuries. Chondrocyte transplant represents a promising therapeutic modality for articular cartilage injuries. Here, we characterize the viability and transgene expression of articular chondrocytes cultured in three-dimensional scaffolds provided by four types of carriers. Articular chondrocytes are isolated from rabbit knees and cultured in four types of scaffolds: type I collagen sponge, fibrin glue, hyaluronan, and open-cell polylactic acid (OPLA). The cultured cells are transduced with adenovirus expressing green fluorescence protein (AdGFP) and luciferase (AdGL3-Luc). The viability and gene expression in the chondrocytes are determined with fluorescence microscopy and luciferase assay. Cartilage matrix production is assessed by Alcian blue staining. Rabbit articular chondrocytes are effectively infected by AdGFP and exhibited sustained GFP expression. All tested scaffolds support the survival and gene expression of the infected chondrocytes. However, the highest transgene expression is observed in the OPLA carrier. At 4 weeks, Alcian blue-positive matrix materials are readily detected in OPLA cultures. Thus, our results indicate that, while all tested carriers can support the survival of chondrocytes, OPLA supports the highest transgene expression and is the most conductive scaffold for matrix production, suggesting that OPLA may be a suitable scaffold for cell-based gene therapy of articular cartilage repairs.

Biphasic effects of TGFβ1 on BMP9-induced osteogenic differentiation of mesenchymal stem cells

We have found that the previously uncharacterized bone morphogenetic protein-9 (BMP9) is one of the most osteogenic factors. However, it is unclear if BMP9 cross-talks with TGFβ1 during osteogenic differentiation. Using the recombinant BMP9 adenovirus, we find that low concentration of rhTGFβ1 synergistically induces alkaline phosphatase activity in BMP9-transduced C3H10T1/2 cells and produces more pronounced matrix mineralization. However, higher concentrations of TGFβ1 inhibit BMP9-induced osteogenic activity. Real-time PCR and Western blotting indicate that BMP9 in combination with low dose of TGFβ1 potentiates the expression of later osteogenic markers osteopontin, osteocalcin and collagen type 1 (COL1a2), while higher concentrations of TGFβ1 decrease the expression of osteopontin and osteocalcin but not COL1a2. Cell cycle analysis reveals that TGFβ1 inhibits C3H10T1/2 proliferation in BMP9-induced osteogenesis and restricts the cells in G(0)/G(1) phase. Our findings strongly suggest that TGFβ1 may exert a biphasic effect on BMP9-induced osteogenic differentiation of mesenchymal stem cells.

The Current and Future Therapies for Human Osteosarcoma

Osteosarcoma (OS) is the most common non-hematologic malignant tumor of bone in adults and children. As sarcomas are more common in adolescents and young adults than most other forms of cancer, there are a significant number of years of life lost secondary to these malignancies. OS is associated with a poor prognosis secondary to a high grade at presentation, resistance to chemotherapy and a propensity to metastasize to the lungs. Current OS management involves both chemotherapy and surgery. The incorporation of cytotoxic chemotherapy into therapeutic regimens escalated cure rates from <20% to current levels of 65-75%. Furthermore, limb-salvage surgery is now offered to the majority of OS patients. Despite advances in chemotherapy and surgical techniques over the past three decades, there has been stagnation in patient survival outcome improvement, especially in patients with metastatic OS. Thus, there is a critical need to identify novel and directed therapy for OS. Several Phase I trials for sarcoma therapies currently ongoing or recently completed have shown objective responses in OS. Novel drug delivery mechanisms are currently under phase II and III clinical trials. Furthermore, there is an abundance of preclinical research which holds great promise in the development of future OS-directed therapeutics. Our continuously improving knowledge of the molecular and cell-signaling pathways involved in OS will translate into more effective therapies for OS and ultimately improved patient survival. The present review will provide an overview of current therapies, ongoing clinical trials and therapeutic targets under investigation for OS.

Inhibitory effect of adenovirus-mediated siRNA-targeting BMPR-IB on UHMWPE-induced bone destruction in the murine air pouch model

OBJECTIVE

Adenovirus expressing small interfering RNA (siRNA)-targeting BMPR-IB was locally administered into the air pouch of mice to improve bone resorption induced by ultra-high molecular weight polyethylene (UHMWPE) particles.

METHOD

Air pouches were established on the back of BALB/c mice, followed by the surgical introduction of a section of calvaria from a syngeneic mouse donor. The bone-implanted pouches were stimulated with the UHMWPE suspension. UHMWPE-containing mice were divided into three study groups to receive injections of adenovirus expressing BMPR-IB siRNA (BMPR-IB group), adenovirus expressing missense siRNA, and virus-free culture medium (control group) into the pouches, respectively. The tissues were harvested at 14 days after the treatment for molecular and histological analyses.

RESULTS

Adenovirus-mediated BMPR-IB siRNA treatment significantly improved UHMWPE particle-induced bone resorption, reduced TRAP and RANK gene and protein expression levels, and diminished the number of TRAP-positive cells. Furthermore, the BMPR-IB siRNA inhibited osteoclast differentiation by targeting osteoblast for the induction of osteoprotegerin formation and downregulation of receptor for activation of nuclear factor-κB ligand production.

CONCLUSIONS

This study suggested that loss of bone morphogenetic protein signaling by BMPR-IB siRNA directs osteoblasts to decrease bone destruction in part by downregulating osteoclastogenesis through the receptor for activation of nuclear factor-κB ligand-osteoprotegerin pathway. Local administration of adenovirus expressing siRNA-targeting BMPR-IB may be a feasible and effective therapeutic candidate to treat or prevent wear debris-associated osteolysis.

All-trans retinoic acid inhibits tumor growth of human osteosarcoma by activating Smad signaling-induced osteogenic differentiation

Osteosarcoma (OS) is one of the most common malignant bone tumors. Despite the advancement of diagnosis and treatment for OS, the prognosis remains poor. We investigated the proliferation inhibitory effect of all-trans retinoic acid (ATRA) for human OS and the possible mechanism underlying this effect. We examined the proliferation inhibition and apoptosis-inducing effects of ATRA in 143B OS cells. We validated this effect by exogenously expressing the retinoic acid receptor alpha (RARα) in 143B OS cells and injecting the cells into nude mice. We explored the possible mechanism for the proliferation inhibitory effect of ATRA on OS cells and multipotential progenitor cells by detecting osteogenic markers. We demonstrated that the endogenous retinoic acid receptor and retinoid X receptor are all detectable in the commercially available OS cell lines and in primary osteosarcoma cells. ATRA inhibits the proliferation of OS cells in a concentration-dependent manner, as well as induces apoptosis in 143B OS cells. The exogenous expression of RARα inhibits the tumor growth and cell proliferation in vivo. The alkaline phosphatase activity, protein levels of osteopontin (OPN) and osteocalcin (OCN) are all promoted by ATRA in OS cells and mouse embryonic fibroblasts (MEFs), at least by activating the Smad signaling pathway. Collectively, our results strongly indicate that ATRA can inhibit the tumor growth of OS by promoting osteogenic differentiation in OS cells, which is mediated in part by activating Smad signaling. Therefore, combination of ATRA with other current chemotherapy agents may be a promising therapy strategy for OS treatment.

BMP-9 induced osteogenic differentiation of mesenchymal stem cells: molecular mechanism and therapeutic potential

Promoting osteogenic differentiation and efficacious bone regeneration have the potential to revolutionize the treatment of orthopaedic and musculoskeletal disorders. Mesenchymal Stem Cells (MSCs) are bone marrow progenitor cells that have the capacity to differentiate along osteogenic, chondrogenic, myogenic, and adipogenic lineages. Differentiation along these lineages is a tightly controlled process that is in part regulated by the Bone Morphogenetic Proteins (BMPs). BMPs 2 and 7 have been approved for clinical use because their osteoinductive properties act as an adjunctive treatment to surgeries where bone healing is compromised. BMP-9 is one of the least studied BMPs, and recent in vitro and in vivo studies have identified BMP-9 as a potent inducer of osteogenic differentiation in MSCs. BMP-9 exhibits significant molecular cross-talk with the Wnt/ β-catenin and other signaling pathways, and adenoviral expression of BMP-9 in MSCs increases the expression of osteogenic markers and induces trabecular bone and osteiod matrix formation. Furthermore, BMP-9 has been shown to act synergistically in bone formation with other signaling pathways, including Wnt/ β-catenin, IGF, and retinoid signaling pathways. These results suggest that BMP-9 should be explored as an effective bone regeneration agent, especially in combination with adjuvant therapies, for clinical applications such as large segmental bony defects, non-union fractures, and/or spinal fusions.

The therapeutic potential of the Wnt signaling pathway in bone disorders

The Wnt pathway plays a critical role in development and differentiation of many tissues, such as the gut, hair follicles, and bone. Increasing evidence indicates that Wnts may function as key regulators in osteogenic differentiation of mesenchymal stem cells and bone formation. Conversely, aberrant Wnt signaling is associated with many osteogenic pathologies. For example, genetic alterations in the Wnt signaling pathway lead to osteoporosis and osteopenia, while inactivating mutations of Wnt inhibitors result in a hyperostotic skeleton with increased bone mineral density. Hyperparathyroidism causes osteopenia via induction of the Wnt signaling pathway. Lithium, often used to treat bipolar disorder, blocks a Wnt antagonist, decreasing the patient's risk of fractures. Thus, manipulating the Wnt pathway may offer plenty therapeutic opportunities in treating bone disorders. In fact, induction of the Wnt signaling pathway or inhibition of Wnt antagonists has shown promise in treating bone metabolic disorders, including osteoporosis. For example, antibodies targeting the Wnt inhibitor Sclerostin lead to increased bone mineral density in post-menopausal women. However, such therapies targeting the Wnt pathway are not without risk, as genetic alternations may lead to over-activation of Wnt/β-catenin and its association with many tumors. It is conceivable that targeting Wnt inhibitors may predispose the individuals to tumorigenic phenotypes, at least in bone. Here, we review the roles of Wnt signaling in bone metabolic and pathologic processes, as well as the therapeutic potential for targeting Wnt pathway and its associated risks in bone diseases.

Insulin-like growth factor 2 (IGF-2) potentiates BMP-9-induced osteogenic differentiation and bone formation

Efficient osteogenic differentiation and bone formation from mesenchymal stem cells (MSCs) should have clinical applications in treating nonunion fracture healing. MSCs are adherent bone marrow stromal cells that can self-renew and differentiate into osteogenic, chondrogenic, adipogenic, and myogenic lineages. We have identified bone morphogenetic protein 9 (BMP-9) as one of the most osteogenic BMPs. Here we investigate the effect of insulin-like growth factor 2 (IGF-2) on BMP-9-induced bone formation. We have found that endogenous IGF-2 expression is low in MSCs. Expression of IGF-2 can potentiate BMP-9-induced early osteogenic marker alkaline phosphatase (ALP) activity and the expression of later markers. IGF-2 has been shown to augment BMP-9-induced ectopic bone formation in the stem cell implantation assay. In perinatal limb explant culture assay, IGF-2 enhances BMP-9-induced endochondral ossification, whereas IGF-2 itself can promote the expansion of the hypertropic chondrocyte zone of the cultured limb explants. Expression of the IGF antagonists IGFBP3 and IGFBP4 leads to inhibition of the IGF-2 effect on BMP-9-induced ALP activity and matrix mineralization. Mechanistically, IGF-2 is further shown to enhance the BMP-9-induced BMPR-Smad reporter activity and Smad1/5/8 nuclear translocation. PI3-kinase (PI3K) inhibitor LY294002 abolishes the IGF-2 potentiation effect on BMP-9-mediated osteogenic signaling and can directly inhibit BMP-9 activity. These results demonstrate that BMP-9 crosstalks with IGF-2 through PI3K/AKT signaling pathway during osteogenic differentiation of MSCs. Taken together, our findings suggest that a combination of BMP-9 and IGF-2 may be explored as an effective bone-regeneration agent to treat large segmental bony defects, nonunion fracture, and/or osteoporotic fracture.

Mesenchymal stem cells: Molecular characteristics and clinical applications

Mesenchymal stem cells (MSCs) are non-hematopoietic stem cells with the capacity to differentiate into tissues of both mesenchymal and non-mesenchymal origin. MSCs can differentiate into osteoblastic, chondrogenic, and adipogenic lineages, although recent studies have demonstrated that MSCs are also able to differentiate into other lineages, including neuronal and cardiomyogenic lineages. Since their original isolation from the bone marrow, MSCs have been successfully harvested from many other tissues. Their ease of isolation and ex vivo expansion combined with their immunoprivileged nature has made these cells popular candidates for stem cell therapies. These cells have the potential to alter disease pathophysiology through many modalities including cytokine secretion, capacity to differentiate along various lineages, immune modulation and direct cell-cell interaction with diseased tissue. Here we first review basic features of MSC biology including MSC characteristics in culture, homing mechanisms, differentiation capabilities and immune modulation. We then highlight some in vivo and clinical evidence supporting the therapeutic roles of MSCs and their uses in orthopedic, autoimmune, and ischemic disorders.

Retinoic acids potentiate BMP9-induced osteogenic differentiation of mesenchymal progenitor cells

Background

As one of the least studied bone morphogenetic proteins (BMPs), BMP9 is one of the most osteogenic BMPs. Retinoic acid (RA) signaling is known to play an important role in development, differentiation and bone metabolism. In this study, we investigate the effect of RA signaling on BMP9-induced osteogenic differentiation of mesenchymal progenitor cells (MPCs).

Methodology/Principal Findings

Both primary MPCs and MPC line are used for BMP9 and RA stimulation. Recombinant adenoviruses are used to deliver BMP9, RARα and RXRα into MPCs. The in vitro osteogenic differentiation is monitored by determining the early and late osteogenic markers and matrix mineralization. Mouse perinatal limb explants and in vivo MPC implantation experiments are carried out to assess bone formation. We find that both 9CRA and ATRA effectively induce early osteogenic marker, such as alkaline phosphatase (ALP), and late osteogenic markers, such as osteopontin (OPN) and osteocalcin (OC). BMP9-induced osteogenic differentiation and mineralization is synergistically enhanced by 9CRA and ATRA in vitro. 9CRA and ATRA are shown to induce BMP9 expression and activate BMPR Smad-mediated transcription activity. Using mouse perinatal limb explants, we find that BMP9 and RAs act together to promote the expansion of hypertrophic chondrocyte zone at growth plate. Progenitor cell implantation studies reveal that co-expression of BMP9 and RXRα or RARα significantly increases trabecular bone and osteoid matrix formation.

Conclusion/Significance

Our results strongly suggest that retinoid signaling may synergize with BMP9 activity in promoting osteogenic differentiation of MPCs. This knowledge should expand our understanding about how BMP9 cross-talks with other signaling pathways. Furthermore, a combination of BMP9 and retinoic acid (or its agonists) may be explored as effective bone regeneration therapeutics to treat large segmental bony defects, non-union fracture, and/or osteoporotic fracture.

TGFbeta/BMP type I receptors ALK1 and ALK2 are essential for BMP9-induced osteogenic signaling in mesenchymal stem cells

Mesenchymal stem cells (MSCs) are bone marrow stromal cells that can differentiate into multiple lineages. We previously demonstrated that BMP9 is one of the most potent BMPs to induce osteogenic differentiation of MSCs. BMP9 is one of the least studied BMPs. Whereas ALK1, ALK5, and/or endoglin have recently been reported as potential BMP9 type I receptors in endothelial cells, little is known about type I receptor involvement in BMP9-induced osteogenic differentiation in MSCs. Here, we conduct a comprehensive analysis of the functional role of seven type I receptors in BMP9-induced osteogenic signaling in MSCs. We have found that most of the seven type I receptors are expressed in MSCs. However, using dominant-negative mutants for the seven type I receptors, we demonstrate that only ALK1 and ALK2 mutants effectively inhibit BMP9-induced osteogenic differentiation in vitro and ectopic ossification in MSC implantation assays. Protein fragment complementation assays demonstrate that ALK1 and ALK2 directly interact with BMP9. Likewise, RNAi silencing of ALK1 and ALK2 expression inhibits BMP9-induced BMPR-Smad activity and osteogenic differentiation in MSCs both in vitro and in vivo. Therefore, our results strongly suggest that ALK1 and ALK2 may play an important role in mediating BMP9-induced osteogenic differentiation. These findings should further aid us in understanding the molecular mechanism through which BMP9 regulates osteogenic differentiation of MSCs.

The CCN proteins: important signaling mediators in stem cell differentiation and tumorigenesis

The CCN proteins contain six members, namely CCN1 to CCN6, which are small secreted cysteine-rich proteins. The CCN proteins are modular proteins, containing up to four functional domains. Many of the CCN members are induced by growth factors, cytokines, or cellular stress. The CCNs show a wide and highly variable expression pattern in adult and in embryonic tissues. The CCN proteins can integrate and modulate the signals of integrins, BMPs, VEGF, Wnts, and Notch. The involvement of integrins in mediating CCN signaling may provide diverse context-dependent responses in distinct cell types. CCN1 and CCN2 play an important role in development, angiogenesis and cell adhesion, whereas CCN3 is critical to skeletal and cardiac development. CCN4, CCN5 and CCN6 usually inhibit cell growth. Mutations of Ccn6 are associated with the progressive pseudorheumatoid dysplasia and spondyloepiphyseal dysplasia tarda. In stem cell differentiation, CCN1, CCN2, and CCN3 play a principal role in osteogenesis, chondrogenesis, and angiogenesis. Elevated expression of CCN1 is associated with more aggressive phenotypes of human cancer, while the roles of CCN2 and CCN3 in tumorigenesis are tumor type-dependent. CCN4, CCN5 and CCN6 function as tumor suppressors. Although CCN proteins may play important roles in fine-tuning other major signaling pathways, the precise function and mechanism of action of these proteins remain undefined. Understanding of the biological functions of the CCN proteins would not only provide insight into their roles in numerous cellular processes but also offer opportunities for developing therapeutics by targeting CCN functions.

Synergistic antitumor effect of the activated PPARgamma and retinoid receptors on human osteosarcoma

PURPOSE

Osteosarcoma is the most common primary malignancy of bone. The long-term survival of osteosarcoma patients hinges on our ability to prevent and/or treat recurrent and metastatic lesions. Here, we investigated the activation of peroxisome proliferator-activated receptor gamma (PPARgamma) and retinoid receptors as a means of differentiation therapy for human osteosarcoma.

EXPERIMENTAL DESIGN

We examined the endogenous expression of PPARgamma and retinoid receptors in a panel of osteosarcoma cells. Ligands or adenovirus-mediated overexpression of these receptors were tested to inhibit proliferation and induce apoptosis of osteosarcoma cells. Osteosarcoma cells overexpressing the receptors were introduced into an orthotopic tumor model. The effect of these ligands on osteoblastic differentiation was further investigated.

RESULTS

Endogenous expression of PPARgamma and isotypes of retinoic acid receptor (RAR) and retinoid X receptor (RXR) is detected in most osteosarcoma cells. Troglitazone, 9-cis retinoic acid (RA), and all-trans RA, as well as overexpression of PPARgamma, RARalpha, and RXRalpha, inhibit osteosarcoma cell proliferation and induce apoptosis. A synergistic inhibitory effect on osteosarcoma cell proliferation is observed between troglitazone and retinoids, as well as with the overexpression pairs of PPARgamma/RARalpha, or PPARgamma/RXRalpha. Overexpression of PPARgamma, RARalpha, RXRalpha, or in combinations inhibits osteosarcoma tumor growth and cell proliferation in vivo. Retinoids (and to a lesser extent, troglitazone) are shown to promote osteogenic differentiation of osteosarcoma cells and mesenchymal stem cells.

CONCLUSIONS

Activation of PPARgamma, RARalpha, and RXRalpha may act synergistically on inhibiting osteosarcoma cell proliferation and tumor growth, which is at least partially mediated by promoting osteoblastic differentiation of osteosarcoma cells.

Osteogenic BMPs promote tumor growth of human osteosarcomas that harbor differentiation defects

Osteosarcoma (OS) is the most common primary malignancy of bone. Here, we investigated a possible role of defective osteoblast differentiation in OS tumorigenesis. We found that basal levels of the early osteogenic marker alkaline phosphatase (ALP) activity were low in OS lines. Osteogenic regulators Runx2 and OSX, and the late marker osteopontin (OPN) expressed at low levels in most OS lines, indicating that most OS cells fail to undergo terminal differentiation. Furthermore, OS cells were refractory to osteogenic BMP-induced increases in ALP activity. Osteogenic BMPs were shown to upregulate early target genes, but not late osteogenic markers OPN and osteocalcin (OC). Furthermore, osteogenic BMPs failed to induce bone formation from human OS cells, rather effectively promoted OS tumor growth in an orthotopic OS model. Exogenous expression of early target genes enhanced BMP-stimulated OS tumor growth, whereas osteogenic BMP-promoted OS tumor growth was inhibited by exogenous Runx2 expression. These results suggest that alterations in osteoprogenitors may disrupt osteogenic differentiation pathway. Thus, identifying potential differentiation defects in OS tumors would allow us to reconstruct the tumorigenic events in osteoprogenitors and to develop rational differentiation therapies for clinical OS management.

A protocol for rapid generation of recombinant adenoviruses using the AdEasy system

Recombinant adenoviruses provide a versatile system for gene expression studies and therapeutic applications. We have developed an approach that simplifies the generation and production of such viruses called the AdEasy system. A recombinant adenoviral plasmid is generated with a minimum of enzymatic manipulations, employing homologous recombination in bacteria rather than in eukaryotic cells. After transfection of such plasmids into a mammalian packaging cell line, viral production is conveniently followed with the aid of GFP encoded by a gene incorporated into the viral backbone. This system has expedited the process of generating and testing recombinant adenoviruses for a variety of purposes. In this protocol, we describe the practical aspects of using the AdEasy system for generating recombinant adenoviruses. The full protocol usually takes 4-5 weeks to complete.

Regulation of osteogenic differentiation during skeletal development

Bone formation during skeletal development involves a complex coordination among multiple cell types and tissues. Bone is of crucial importance for the human body, providing skeletal support, and serving as a home for the formation of hematopoietic cells and as a reservoir for calcium and phosphate. Bone is also continuously remodeled in vertebrates throughout life. Osteoblasts and osteoclasts are specialized cells responsible for bone formation and resorption, respectively. Early development of the vertebrate skeleton depends on genes that control the distribution and proliferation of cells from cranial neural crest, sclerotomes, and lateral plate mesoderm into mesenchymal condensations, where cells differentiate to osteoblasts. Significant progress has been made over the past decade in our understanding of the molecular framework that controls osteogenic differentiation. A large number of morphogens, signaling molecules, and transcriptional regulators have been implicated in regulating bone development. A partial list of these factors includes the Wnt/beta-catenin, TGF-beta/BMP, FGF, Notch and Hedgehog signaling pathways, and Runx2, Osterix, ATF4, TAZ, and NFATc1 transcriptional factors. A better understanding of molecular mechanisms behind osteogenic differentiation would not only help us to identify pathogenic causes of bone and skeletal diseases but also lead to the development of targeted therapies for these diseases.

BMP-14 gene therapy increases tendon tensile strength in a rat model of Achilles tendon injury

BACKGROUND

Molecular and cellular-based enhancements of healing combined with conventional methods may yield better outcomes after the surgical management of tendon injury. We examined the histological and biomechanical effects of adenovirus-mediated transgene expression of bone morphogenetic protein-14 (BMP-14) on healing in a rat Achilles tendon laceration model. Specifically, we hypothesized that this delivery system for gene therapy would hasten the restoration of the normal histological appearance and tensile strength of a surgically repaired tendon.

METHODS

The right Achilles tendon of ninety male Sprague-Dawley rats was transected, repaired, and immediately infected with adenovirus expressing either the gene for green fluorescent protein (AdGFP) or the gene for human BMP-14 and green fluorescent protein (AdBMP-14). A sham control group received no viral-mediated infection after repair. Animals from each of the three groups were killed at one, two, and three weeks after surgery. The retrieved tendons were inspected, examined under light and fluorescent microscopy, and tested to determine their tensile strength.

RESULTS

Tendons transduced with BMP-14 exhibited less visible gapping, a greater number of neotenocytes at the site of healing, and 70% greater tensile strength than did either those transduced with GFP or the sham controls at two weeks after repair. Histological examination revealed no inflammatory response to the adenovirus in tendons transduced with BMP-14 or GFP. No ectopic bone or cartilage formed in the tendons transduced with BMP-14.

CONCLUSIONS

Adenovirus-mediated gene therapy with BMP-14 expedites tendon-healing in this animal model. No adverse immunological response to the adenoviral vector was detected in the host tissue, and the local production of BMP-14 did not induce unwelcome bone or cartilage formation within the healing tendon.

CLINICAL RELEVANCE

The results of this animal study suggest that gene therapy with BMPs may improve the capacity of injured musculoskeletal tissue to heal.

Distinct roles of bone morphogenetic proteins in osteogenic differentiation of mesenchymal stem cells

Efficacious bone regeneration could revolutionize the clinical management of many bone and musculoskeletal disorders. Bone morphogenetic proteins (BMPs) can regulate the differentiation of mesenchymal stem cells into cartilage, bone, tendon/ligament, and fat lineages. Early data documented the osteogenic potential of rhBMP2 and rhBMP7/OP-1. However, prior to this work that summarized several of our recent studies, no comprehensive analysis had been undertaken to characterize relative osteogenic activity of all BMPs. Using recombinant adenoviruses expressing 14 BMPs, we have demonstrated that, besides BMP2 and BMP7, BMP6 and BMP9 exhibit the highest osteogenic activity both in vitro and in vivo. We further demonstrated that several BMPs may exert synergistic effect on osteogenic differentiation, and that osteogenic BMPs produce a distinct set of molecular fingerprints during osteogenic differentiation. The reported work should expand our current understanding of BMP functions during osteogenic differentiation. It is conceivable that osteogenic BMPs (i.e., BMP2, 4, 6, 7, and 9) may be used to formulate synergistic pairs among themselves and/or with other less osteogenic BMPs for efficacious bone regeneration in clinical settings.

Selection and validation of optimal siRNA target sites for RNAi-mediated gene silencing

RNA interference (RNAi)-mediated gene silencing has become a valuable tool for functional studies, reverse genomics, and drug discoveries. One major challenge of using RNAi is to identify the most effective short interfering RNAs (siRNAs) sites of a given gene. Although several published bioinformatic prediction models have proven useful, the process to select and validate optimal siRNA sites for a given gene remains empirical and laborious. Here, we developed a fluorescence-based selection system using a retroviral vector backbone, namely pSOS, which was based on the premise that candidate siRNAs would knockdown the chimeric transcript between GFP and target gene. The expression of siRNA was driven by the opposing convergent H1 and U6 promoters. This configuration simplifies the cloning of duplex siRNA oligonucleotide cassettes. We demonstrated that GFP signal reduction was closely correlated with siRNA knockdown efficiency of human beta-catenin, as well as with the inhibition of beta-catenin/Tcf4 signaling activity. The pSOS should not only facilitate the selection and validation of candidate siRNA sites, but also provide efficient delivery tools of siRNAs via viral vectors in mammalian cells. Thus, the pSOS system represents an efficient and user-friendly strategy to select and validate siRNA target sites.

Wnt signaling and human diseases: what are the therapeutic implications?

Wnt signaling plays an important role in regulating cell proliferation and differentiation. De-regulation of these signaling pathways has been implicated in many human diseases, ranging from cancers to skeletal disorders. Wnt proteins are a large family of secreted factors that bind to the Frizzled receptors and LRP5/6 co-receptors and initiate complex signaling cascades. Over the past two decades, our understanding of Wnt signaling has been significantly improved due to the identification of many key regulators and mediators of these pathways. Given that Wnt signaling is tightly regulated at multiple cellular levels, these pathways themselves offer ample nodal points for targeted therapeutics. Here, we focus on our current understanding of these pathways, the associations of Wnt signaling with human disorders, and the opportunities to target key components of Wnt signaling for rational drug discovery.

[Expression of inducible nitric oxide synthase was regulated by activating nuclear factor kappaB in mouse macrophages stimulated with ureaplasma urealyticum lipid-associated membrane proteins]

The aim was to investigate the molecular mechanisms responsible for the inducible nitric oxide synthase (iNOS) gene expression stimulated by lipid associated membrane proteins (LAMPs) of Ureaplasma urealyticum (Uu). Mouse macrophages were stimulated by Ureaplasma urealyticum LAMPs to analyze the production of nitric oxide (NO) and the expression of iNOS detected by RT-PCR and Western blot. The activation of NF-kappaB was examined in mouse macrophages treated with LAMPs by indirect immunofluorescence (IFA), immunocytochemistry and Western blot. The effects of pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-kappaB and of cycloheximide (CHX), a protein synthase inhibitor, on the expression of iNOS and on the activation of NF-kappaB were also investigated in mouse macrophages treated with LAMPs. Results showed Ureaplasma urealyticum LAMPs stimulated mouse macrophages to express iNOS and thus produce NO in dose- and time-dependent manners by activating nuclear factor kappaB. The activation of NF-kappaB and the expression of iNOS were inhibited by LAMPs combination with PDTC or CHX. In conclusion, these findings suggested Ureaplasma urealyticum may be an important pathogenic factor due to the ability of LAMPs to stimulate the expression of iNOS, which is probably medicated by the activation of NF-kappaB.

Effect of prepyloric gastric transection and anastomosis on sphincter of Oddi cyclic motility in conscious dogs

PURPOSE

We previously reported significant changes in sphincter of Oddi cyclic motility after proximal duodenal transection and anastomosis. However, the role of intrinsic myoneural continuity between the antrum and duodenum in this respect is not understood. The aim of this study was to elucidate the effects of prepyloric gastric transection on sphincter of Oddi motility in animals in the conscious state.

METHODS

Pressures in the bile duct, duodenum, stomach, and sphincter of Oddi and their response to an injection of cholecystokinin-octapeptide were measured in four conscious dogs, with a duodenal cannula, before and after gastric transection and anastomosis 1.5 cm proximal to the pylorus.

RESULTS

Gastric transection did not affect the initiation and propagation of the gastroduodenal migration motor complex. Biliary pressure (5.7 +/- 0.15 to 5.5 +/- 0.2 mmHg; P = 0.91), sphincter of Oddi basal pressure (10.6 +/- 0.3 to 10.7 +/- 0.2 mmHg; P = 0.97), and amplitude (26.0 +/- 1.2 to 32.9 +/- 1.7 mmHg; P = 0.304) did not change after gastric transection. Biliary pressure decreased from phase II to phase III of the duodenal migrating motor complex. Cholecystokinin-octapeptide inhibited sphincter of Oddi phasic waves before and after gastric transection.

CONCLUSIONS

Intrinsic myoneural transection at the prepyloric region does not influence sphincter of Oddi cyclic motility. Preservation of pyloroduodenal myoneural continuity in pylorus-preserving gastrectomy would be beneficial to maintain normal sphincter of Oddi motility.

Effects of proximal duodenal transection and anastomosis on interdigestive sphincter of Oddi cyclic motility in conscious dogs

Gallstones formed after gastrectomy are bilirubinate stones probably associated with biliary stasis and infection. Effects of proximal duodenal transection performed during gastrectomy on interdigestive sphincter of Oddi cyclic motility possibly relevant to this phenomenon were investigated in four conscious dogs. Although the cyclic change in sphincter motility was still in concert with the duodenal migrating motor complex after duodenal transection, the mean period was shortened (p < 0.02), and the frequency (p < 0.005) and amplitude (p < 0.001) of sphincter phasic waves during phase III were decreased. The cyclic variation of basal pressure disappeared, and the mean basal pressure throughout the cycle was significantly reduced (p < 0.003). Transient inhibition of sphincter and duodenal contractions normally seen during phase III disappeared. Duodenal transection reversed the response of the sphincter to cholecystokinin-octapeptide from inhibition to stimulation and from reduction of the basal pressure to elevation. These data suggest that duodenal transection produces significant changes in interdigestive sphincter of Oddi motility, possibly contributing to augmented duodenobiliary reflux and then lithogenesis. Myoneural continuity between the stomach and sphincter of Oddi at the proximal duodenum may play an important role in maintaining normal biliary dynamics.

Vector manometric study of the sphincter of Oddi in the dog: functional and morphological correlation

The relationship between sphincter of Oddi pressure and the morphological structure of the sphincter was studied in eight dogs prepared with a duodenal cannula. Sphincter of Oddi manometry was performed in awake animals in three directions, ventral, left dorsal, and right dorsal, using a catheter with three radial side holes for recording at one level. The pressure in the ventral direction (26.6+/-1.06 mmHg) (mean+/-SEM) was significantly lower than that in the left and right dorsal directions (30.6+/-1.42 and 31.2+/-1.23 mmHg, respectively). This functional manometric difference in the three directions correlated closely with the morphological structure of the sphincter of Oddi; the sum of the thickness of the sphincter of Oddi muscle and duodenal proper muscle was greater on the dorsal than on the ventral side. To our knowledge, this is the first report of axial asymmetry in sphincter of Oddi pressure.

Polymorphisms of dopamine D2-like (D2, D3, and D4) receptors in schizophrenia

The result of most association studies and linkage analyses have suggested a negative association between schizophrenia and D2-like (D2, D3, and D4) receptor polymorphisms. Although the polymorphisms of the D2-like receptor in themselves may not account for the etiology of schizophrenia, they can contribute to the severity of the symptoms. Thus, we studied the associations between the polymorphisms and their combinations, and the vulnerability of schizophrenics. Fragments of the D2-like receptor genes were amplified by means of the polymerase chain reaction, and the polymorphisms were identified by the restriction fragment length polymorphism and single-stranded conformation polymorphism methods. There were no statistically significant differences in the polymorphisms and their combinations between schizophrenics and controls. Schizophrenics with D4E1(A1/A2), which contains 2 and 1 tandem repeats of a 12-base-pair sequence in exon 1, had a lower total positive symptom score before medication than schizophrenics with D4E1(A1/A1). There was no association between the polymorphisms and negative symptoms.

Effects of intraduodenal air insufflation on sphincter of Oddi motility in conscious dogs

To investigate effects of intraduodenal air insufflation on sphincter of Oddi motility, manometric recordings were obtained during fasting from the sphincter and duodenum in four conscious dogs with duodenal cannula. At 40% of the mean cycle length of the migrating motor complex predetermined from baseline recording, 160 ml of air was injected into the duodenum. In both the sphincter and duodenum, air insufflation produced premature phase III-like activity in seven of 20 experiments (35%) or nonspecific excitatory reaction in eight (40%). In the remaining five experiments (25%), the sphincter exhibited a transient inhibitory response, while the duodenum showed the nonspecific excitatory reaction. Basal pressure of the sphincter increased immediately after air insufflation in 90% of the 20 experiments. The mean basal pressure increased from 12.3 +/- 1.6 mm Hg to 22.4 +/- 2.1 mm Hg (P < 0.0001) and minimum basal pressure from 2.9 +/- 0.9 mm Hg to 4.7 +/- 0.8 mm Hg (P < 0.001). These results indicate that intraduodenal air insufflation does affect motility of the sphincter of Oddi and duodenum in conscious dogs.

The genes encoding the 5HT1D alpha and 5HT1D beta receptors are unchanged in patients with panic disorder

To determine the serotonergic function in panic disorder, sequencing of the genes encoding the 5HT1D alpha and 5HT1D beta receptors was carried out. The genes for the 5HT1D alpha and 5HT1D beta receptors were amplified by polymerase chain reaction and sequenced by the dideoxy method. Some patients have both nucleotides C and T at position 1080 in 5HT1D alpha receptor gene; however, both of them code the same amino acid, asparagine. The 5HT1D beta receptor gene had a substitution from GCA276 to GCG276, not only panic disorder but also in controls; however, this substitution does not change the corresponding amino acid, alanine92.

Male breast cancer--a report of 4 cases and a review of the literature

Male breast cancer represents only about 1% of all breast cancers. Of 451 patients with breast cancer, we have experienced four cases of male breast cancer. Characteristics of these male patients with breast cancer were an older age at diagnosis (mean: 68.5 years old), prolonged duration of symptom (ranged from 1 month to 6 years with a mean of 25.5 months), centrally located tumor, advanced staging and infiltrating ductal carcinoma in histologic type. Some reported risk factors for the development of male breast cancer, such as radiation exposure, hormonal factors and gallstone disease were present.

The gene encoding the 5-HT1A receptor is intact in mood disorders

We studied the 5-HT1A receptor gene in 50 mood disorders and 50 normal volunteers. The 5-HT1A receptor gene was amplified by polymerase chain reaction and sequenced by the dideoxy method. The sequence of the 5-HT1A receptor encodes a protein of 422 amino acids, that is, one amino acid longer than the reported sequence (Kobilka et al. 1987). The DNA sequence at positions 454 to 459 is CGC GCC GCT, not CCG CGT, and the amino acids sequence at these positions is changing from proline arginine to arginine alanine alanine. These differences, however, were observed in both mood disorders and controls. One silent polymorphism, CTG to GTA at position 294, was found. These results suggest that the 5-HT1A receptor gene is intact in mood disorders.

The influence of age and location of arterial lesion on the pathogenesis and development of early atherosclerotic lesions in youth

From 1986 to 1989, 324 aortae from accidental death aged 15-39 were collected from two locations, one of higher prevalence (Beijing in North China), and the other of lower prevalence (Nanning in South China) of atherosclerosis (AS) and coronary heart disease (CHD). Morphometry and biochemical analyses, were used in the study with emphasis on the changes of smooth muscle cells (SMC) in the aortic intima and on the aortic proteoglycans (PGs) of specimens from both locations to elucidate their relationship with the pathogenesis and development of AS and to find ways, if any, for the prevention and control of AS. The results showed that the densities, especially the area density of the cell nuclei of aortic SMC were significantly higher in specimens from the North than those from the South (P < 0.01). Nuclear densities of SMC negatively correlated with alcian blue-positive substances; both total PGs and Heparin sulfate PG (HSPG, inhibitory to SMC proliferation) of the aortic intima and media were lower in specimens from the North than those from the South (P < 0.01). The percentage of sudanophilic lesion (SL) in the total intimal area, showing the extent of fatty infiltration of aortae from the two locations, was similar except that of the male abdominal aortae which was higher in the North (P < 0.01). The above findings showed that decreased content of HSPG which is inhibitory to SMC proliferation might be one of the causes of the augmentation of aortic SMC proliferation in Beijing specimens; and also the increased serum cholesterol concentration of the population in Nanning was reflected in the SL of the aortic intima.(ABSTRACT TRUNCATED AT 250 WORDS)

Human aortic proteoglycans of subjects from districts of high and low prevalence of atherosclerosis in China

The contents of three species of proteoglycans (PGs), heparan sulfate PG(HSPG), chondroitin sulfate PG(CSPG) and dermatan sulfate chondroitin sulfate PG(DSCSPG), in human thoracic aortas of subjects from districts of high (Beijin, in North China) and low (Nanning, in South China) prevalence of atherosclerosis in China were quantitated. Higher aortic HSPG and DSCSPG (but lower DS) in samples from Nanning than those from Beijing might be implicated in the lower prevalence of atherosclerosis in the former.

Human penicilliosis marneffei and its relation to the bamboo rat (Rhizomys pruinosus)

Fourteen cases of penicilliosis marneffei occurred in persons in the Guangxi region of the People's Republic of China; the first known case of that disease had been found in Vietnamese bamboo rats (Rhizomys sinensis). A survey of the wild rats in this region was initiated to determine if any of these animals were infected by Penicillium marneffei. Although R. sinensis rats live in the study area, they are relatively rare. The only rats captured were another species of bamboo rat (R. pruinosus). Of the 19 rats captured, 18 yielded cultures of P. marneffei from one or more of their internal organs. The implications of this finding in respect to the epidemiology of penicilliosis marneffei are discussed.

Progressive disseminated penicilliosis caused by Penicillium marneffei. Report of eight cases and differentiation of the causative organism from Histoplasma capsulatum

Eight patients with fatal penicilliosis caused by Penicillium marneffei are reported. All were natives of southern rural Guangxi, and none had a predisposing illness or evidence of altered immunity. The distinctive features of P. marneffei include proliferation of yeast-like cells within histiocytes, followed by the development of focal necrosis and, eventually, large abscesses. Outside the histiocytes, the fungi elongate, become slightly curved, and form septa. In vitro, P. marneffei produces a red pigment which diffuses into the culture medium. The differentiation between P. marneffei and Histoplasma capsulatum is described, and possible reservoirs for P. marneffei are discussed.