Acute osteomyelitis of the patella due to Pseudomonas aeruginosa in an immunocompetent child: A case report.

RATIONALE: Plentiful vascularity and lack of the physis are thought to render the patella less vulnerable to osteomyelitis. Pseudomonas aeruginosa (PA) is an opportunistic pathogen predominantly affecting immunocompromised hosts. Despite the ubiquitous nature of PA, osteomyelitis of the patella caused by PA has been rarely reported in children. PATIENT CONCERNS: A 5-year-old boy who had presented with a prolonged history of the left anterior knee pain following minor trauma was diagnosed with prepatellar bacterial cellulitis and bursitis. Afterward, a focal osteolytic lesion emerged at the ventral surface of the patella despite oral and intravenous antibiotic therapy lasting for weeks. We described clinical presentation as well as medical and surgical management of pediatric patellar osteomyelitis secondary to prepatellar septic bursitis. DIAGNOSES: Pseudomonas aeruginosa-associated osteomyelitis of the patella. Magnetic resonance imaging of the left knee showed a focal destructive change of the ventral half of the cartilaginous patella and a suprapatellar joint effusion. Bacterial culture from the bursa revealed Pseudomonas aeruginosa. INTERVENTIONS: Systemic inflammation, patellar osteochondral destruction, and purulent synovial fluid of the knee were prolonged for 6 weeks despite antibiotics use deemed appropriate and reparative surgical debridement, whereas they were eventually resolved with a 6-week course of intravenous ceftazidime and cessation of continuous intracapsular irrigation. OUTCOMES: He was clinically asymptomatic at the latest follow-up but exhibited a minor leg length discrepancy <2 cm associated with overgrowth of the affected femur. LESSONS: This is a rare case of Pseudomonas osteomyelitis of the patella in a healthy pediatric patient. Uncommon osteochondral sequelae occurred probably because of a protracted arthritis of the affected knee. We would like to emphasize the ineffectiveness of continuous irrigation without antibiotics for Pseudomonas aeruginosa-associated osteomyelitis.

Satellite forecasting of crop harvest can trigger a cross-hemispheric production response and improve global food security.

Global food security is increasingly threatened by climate change and regional human conflicts. Abnormal fluctuations in crop production in major exporting countries can cause volatility in food prices and household consumption in importing countries. Here we show that timely forecasting of crop harvest from satellite data over major exporting regions can trigger production response in the opposite hemisphere to offset the short-term fluctuations and stabilize global food supply. Satellite forecasting can reduce the fluctuation extents of country-level prices by 1.1 to 12.5 percentage points for anticipated wheat shortage or surplus in Russia and Ukraine, and even reverse the price shock in importing countries for anticipated soybean shortage in Brazil. Our research demonstrates that by leveraging the seasonal lags in crop calendars between the Northern and Southern Hemispheres, operational crop monitoring from satellite data can provide a mechanism to improve global food security.

Food Import Dependency and National Food Security: A Price Transmission Analysis for the Wheat Sector.

Agricultural trade liberalization and protecting domestic markets encompass conflicting policy goals. Even though after the food crisis in 2008, national governments of food-deficit nations aimed at reducing food supply dependency on external markets, no research has assessed the impacts of food import reliance on price or price volatility transmissions to local markets. We constructed a dynamic conditional correlation (DCC)-generalized autoregressive conditional heteroscedasticity (GARCH) model to examine whether wheat import dependency could make a country vulnerable to overseas shocks by analyzing the inter-relationships between the international wheat price and retail wheat flour prices in 10 net importing countries over the sample period from January 2005 to December 2019. It was found that retail price volatility in each region was positively correlated with international price volatility for most of the period concerned. We also discovered that external dependency could significantly protect the domestic market from the global one, implying that lowering wheat dependency on foreign markets improves "stability" and "availability" of food security without sacrificing "utilization", but it may aggravate "access".

Short-Term Implications of Climate Shocks on Wheat-Based Nutrient Flows: A Global "Nutrition at Risk" Analysis through a Stochastic CGE Model.

Food security analyses of international trade largely overlook the importance of substantial heterogeneity and complexity of nutrient content in food products. This paper quantifies the extent to which wheat-based nutrient supplies, including energy, protein, iron, zinc, and magnesium, are exposed to the risks of realistic productivity and trade shocks. By employing a static and stochastic world trade computable general equilibrium (CGE) model, we find that productivity shocks may result in losses in households' nutrient consumption of up to 18% for protein, 33.1% for zinc, and 37.4% for magnesium. Significant losses are observed in countries mostly in the Middle East, North Africa, and Central Asia. Since the main centers of wheat exports have recently been shifting to former Soviet Union countries, we also simulated the nutritional risks of export restrictions imposed by the Russian Federation, Ukraine, and Kazakhstan, which have resorted to this policy instrument in recent years. We find that partial export restrictions increase the probability of nutrient shocks by five times or more in most countries that we studied. Increased nutrient deficiencies have a range of public health implications in the affected countries, which could be mitigated and/or avoided by adjusting production and trade policies and by targeting high nutritional risk groups, such as women and children. Since the potential implications of supply shocks are diffused across countries through international trade, the stricter regulation of export restrictions to enhance the predictably and reliability of global food supplies is also needed.

Report of successful application of the chipping technique in atypical femoral fracture prophylactic surgery.

Treatment using intramedullary nail (IMN) is challenging for atypical femoral incomplete fractures with the bowed femur. Although IMN is the first choice for atypical femoral fractures, there is often a mismatch between the shape of the femur and the implant. Therefore, for prophylactic surgery of atypical femoral incomplete fracture we used IMN with a chipping technique, which is used for non-unions of the longitudinal fracture. We report a case of an 87-year-old woman who presented with bilateral thigh pain that lasted 3 months and gradually worsened. She had a medication history of bisphosphonates for 10 years. In addition, radiography showed severe curvature in her femurs, with radiolucent fracture lines in the diaphysis. We obtained good results by using IMN with the chipping technique. Thigh pain was promptly relieved postoperatively. Four months after surgery, each bone had fused without the need for additional treatment. The chipping technique in prevention surgery of atypical femoral fracture can eliminate the mismatch with the implant by grinding the limited lesion, including the radiolucent fracture line. Moreover, it promotes bone healing.

Semaphorin 4D induces vaginal epithelial cell apoptosis to control mouse postnatal vaginal tissue remodeling.

The opening of the mouse vaginal cavity to the skin is a postnatal tissue remodeling process that occurs at approximately five weeks of age for the completion of female genital tract maturation at puberty. The tissue remodeling process is primarily composed of a hormonally triggered apoptotic process predominantly occurring in the epithelium of the distal section of the vaginal cavity. However, the detailed mechanism underlying the apoptotic induction remains to be elucidated. In the present study, it was observed that the majority of BALB/c mice lacking the class 4 semaphorin, semaphorin 4D (Sema4D), developed imperforate vagina and hydrometrocolpos resulting in a perpetually unopened vaginal cavity regardless of a normal estrogen level comparable with that in wild­type (WT) mice. Administration of ß­estradiol to infant Sema4D­deficient (Sema4D­/­) mice did not induce precocious vaginal opening, which was observed in WT mice subjected to the same ß­estradiol administration, excluding the possibility that the closed vaginal phenotype was due to insufficient estrogen secretion at the time of vaginal opening. In order to assess the role of Sema4D in the postnatal vaginal tissue remodeling process, the expression of Sema4D and its receptor, plexin­B1, was examined as well as the level of apoptosis in the vaginal epithelia of five­week­old WT and Sema4D­/­ mice. Immunohistochemical analyses confirmed the localization of Sema4D and plexin­B1 in the mouse vaginal epithelia. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and immunohistochemistry detecting activated caspase­3 revealed significantly fewer apoptotic cells in situ in the vaginal mucosa of five­week­old Sema4D­/­ mice compared with WT mice. The addition of recombinant Sema4D to Sema4D­/­ vaginal epithelial cells in culture significantly enhanced apoptosis of the vaginal epithelial cells, demonstrating the apoptosis­inducing activity of Sema4D. The experimental reduction of plexin­B1 expression in vaginal epithelial cells demonstrated the integral role of plexin­B1 in Sema4D­induced apoptotic cell death. These results suggest a non­redundant role of Sema4D in the postnatal tissue remodeling process in five­week­old BALB/c mice, which involves the induction of vaginal epithelial cell apoptosis through Sema4D binding to plexin­B1.

Estrogen-dependent proteolytic cleavage of semaphorin 4D and plexin-B1 enhances semaphorin 4D-induced apoptosis during postnatal vaginal remodeling in pubescent mice.

Around the fifth week after birth, the vaginal cavity in female mouse pups opens to the overlaying skin. This postnatal tissue remodeling of the genital tract occurs during puberty, and it largely depends upon hormonally induced apoptosis that mainly occurs in the epithelium at the lower part of the mouse vaginal cavity. Previously, we showed that most BALB/c mice lacking the class IV Semaphorin (Sema4D) develop imperforate vagina and hydrometrocolpos; therefore, we reasoned that the absence of Sema4D-induced apoptosis in vaginal epithelial cells may cause the imperforate vagina. Sema4D signals via the Plexin-B1 receptor; nevertheless detailed mechanisms mediating this hormonally triggered apoptosis are not fully documented. To investigate the estrogen-dependent control of Sema4D signaling during the apoptosis responsible for mouse vaginal opening, we examined structural and functional modulation of Sema4D, Plexin-B1, and signaling molecules by analyzing both wild-type and Sema4D-/- mice with or without ovariectomy. Both the release of soluble Sema4D and the conversion of Plexin-B1 by proteolytic processing in vaginal tissue peaked 5 weeks after birth of wild-type BALB/c mice at the time of vaginal opening. Estrogen supplementation of ovariectomized wild-type mice revealed that both the release of soluble Sema4D and the conversion of Plexin-B1 into an active form were estrogen-dependent and concordant with apoptosis. Estrogen supplementation of ovariectomized Sema4D-/- mice did not induce massive vaginal apoptosis in 5-week-old mice; therefore, Sema4D may be an essential apoptosis-inducing ligand that acts downstream of estrogen action in vaginal epithelium during this postnatal tissue remodeling. Analysis of ovariectomized mice also indicated that Sema4D contributed to estrogen-dependent dephosphorylation of Akt and ERK at the time of vaginal opening. Based on our results, we propose that apoptosis in vaginal epithelium during postnatal vaginal opening is induced by enhanced Sema4D signaling that is caused by estrogen-dependent structural changes of Sema4D and Plexin-B1.

Differential sensitivity to paclitaxel-induced apoptosis and growth suppression in paclitaxel-resistant cell lines established from HEC-1 human endometrial adenocarcinoma cells.

To investigate acquired paclitaxel (PTX) resistance in cancer cells, we established five monoclonal PTX-resistant cell lines from HEC-1 human endometrial adenocarcinoma cells by means of long-term PTX-exposed cultures and limiting dilution cultures. The established PTX-resistant subclones showed apparent resistance to PTX-induced DNA fragmentation but not to PTX-induced growth suppression. None of the five PTX-resistant subclones showed apparent resistance to other anticancer drugs such as cisplatin, etoposide, 5-fluorouracil, pirarubicin-HCl, 4-hydroxy-cyclophosphamide or mitomycin C. Semiquantitative flow cytometric analysis revealed no apparent differential expression of 17 molecules that were previously reported to regulate apoptosis or drug resistance, between the five PTX-resistant subclones and the parent cells. Karyotyping analysis revealed common changes in chromosomes 4 and 18 in the five PTX-resistant subclones but not in the HEC-1 parent cells. These results indicate that PTX-induced growth suppression is regulated by different mechanisms from those involved in PTX-induced apoptosis. It was concluded that these established PTX-resistant subclones can be useful models in studies related to the prevention or treatment of recurrent cancers after PTX chemotherapy.

Impaired death-associated protein kinase-mediated survival signals in 5-fluorouracil-resistant human endometrial adenocarcinoma cells.

A recent study showed that both 5-fluorouracil (5FU)-stimulated apoptosis and Fas-mediated apoptosis in human endometrial adenocarcinoma cells are enhanced by targeted knockdown of endogenous death-associated protein kinase (DAPK) with DAPK small-interfering RNAs. Therefore, we investigated the DAPK survival signals in three 5FU-resistant subclones. DAPK knockdown did not enhance 5FU-stimulated or Fas-mediated apoptosis in any of the three 5FU-resistant subclones, but the subclones acquired resistance to VP16-stimulated cell death that was DAPK-independent. Semi-quantitative flow cytometric analyses showed that there was no differential expression in nine cell surface antigens, including Fas, and six intracellular molecules, including DAPK, that may regulate cell death or survival between the parent cells and 5FU-resistant cells. DAPK mRNA and protein were expressed in the 5FU-resistant subclones at similar levels to the parent cells. These results indicate that acquisition of 5FU-resistance may be accompanied by impairment of common apoptotic signals regulating both DAPK-dependent and DAPK-independent pathways.

Demethylation restores SN38 sensitivity in cells with acquired resistance to SN38 derived from human cervical squamous cancer cells.

Using seven monoclonal SN38-resistant subclones established from ME180 human cervical squamous cell carcinoma cells, we examined the demethylation effects of 5-aza-2'-deoxycytidine (5-aza-CdR) on the SN38-sensitivity of the cells as well as the expression of death-associated protein kinase (DAPK) in the SN38-resistant cells. The DAPK expression levels were evaluated among parent ME180 cells, SN38-resistant ME180 cells and cisplatin-resistant ME180 cells by methylation-specific DAPK-PCR, quantitative RT-PCR and western blot analysis. The SN38-resistant cells co-treated with SN38 and 5-aza-CdR strongly exhibited enhanced SN38-sensitivities resembling those found in the parent cells. In the SN38-resistant subclones, no relationships were found between the restored SN38 sensitivity and hypermethylation of the DAPK promoter, DAPK mRNA expression, DAPK protein expression and induction of DAPK protein after 5-aza-CdR treatment, unlike the strong suppression of 5-aza-CdR-induced DAPK protein expression in the cisplatin-resistant subclones. These findings indicate that reversibly methylated molecules, but not DAPK, may regulate SN38 resistance, and that demethylating agents can be strong sensitizing anticancer chemotherapeutic drugs for SN38-resistant cancers.

STAT3 enhances intracellular Fas-mediated apoptotic signals in HHUA human endometrial epithelial cells.

Several endometrial signal transducer and activator of transcription 3 (STAT3)-activating cytokines are reported to be essential for blastocyst implantation, with inhibition of STAT3 activation in the endometrium also reported to prevent implantation. To investigate STAT3 signals in endometrial epithelial cells, the activation and inactivation effects of STAT3 signals were examined in the human endometrial epithelial cell line HHUA, which is thought to retain many of the intracellular signaling pathways found in normal human endometrial epithelial cells. Five STAT3-activating cytokines, IL-11, IL-10, LIF, oncostatin M and leptin, enhanced the Fas-mediated apoptosis of the HHUA cells without any increase in cell surface Fas antigen expression. STAT3 siRNA transfection suppressed STAT3 expression in HHUA cells and significantly inhibited Fas-mediated cell death. These results indicate that intracellular apoptotic signals in HHUA cells are constitutively activated and regulated by STAT3-mediated signals. This apoptosis-promoting effect of STAT3 in HHUA cells is completely different from many previous reports demonstrating anti-apoptotic effects by STAT3 activation. The STAT3 signals in HHUA cells may be specific to the human endometrial epithelial cell lineage in the regulation of blastocyst implantation.

Serotonin synthesis and metabolism-related molecules in a human prostate cancer cell line.

Prostate cancer is one of the most common tumors in males and its incidence is steadily increasing worldwide. Serotonin or 5-hydroxytryptamine (5-HT) is a well-known neurotransmitter that mediates a wide variety of physiological effects. An increase in the number of 5-HT-releasing neuroendocrine (NE) cells has been correlated with tumor progression. However, it is particularly unclear whether released 5-HT or the release of 5-HT has a role in tumor cell growth. We hypothesized that 5-HT synthesis and metabolism in NE cells regulate the growth of prostate cancer cells. In the present study, 5-HT was found to play a role as a cell growth factor in prostate cancer cells. Moreover, the pharmacological inhibition of 5-HT synthesis and metabolism interrupted the growth of prostate cancer cells. To confirm the existence of 5-HT in prostate cancer cells, we performed ELISA, HPLC, RT-PCR and immunohistochemical analyses. A high expression of tryptophan hydroxylase (TPH-1), dopa decarboxylase (DDC) and monoamine oxidase A (MAO-A) was noted in the prostate cancer cells when compared with normal prostate cells. Previous studies showed that 5-HT stimulated the proliferation of prostate cancer cells mediated by 5-HT receptors 5-HTR1A and R1B. However, cell proliferation was significantly inhibited when siRNA for both DDC and TPH-1 was transfected to the cells. Consequently, we propose that the secretion system of prostate NE cells capable of 5-HT synthesis and metabolism plays a significant role in prostate tumor generation and progression. These findings provide crucial clues for the development of potential pharmacotherapeutics to slow prostate tumor progression.

Suppressed protein expression of the death-associated protein kinase enhances 5-fluorouracil-sensitivity but not etoposide-sensitivity in human endometrial adenocarcinoma cells.

Targeted knockdown of the death-associated protein kinase (DAPK) expression in the endometrial adenocarcinoma HHUA cells reportedly induces cell death by enhancing the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in an autocrine/paracrine manner. This suggests that endogenous DAPK is a potential candidate for a molecularly targeted anticancer therapy for patients with endometrial adenocarcinoma. To investigate the role of endogenous DAPK in anticancer drug sensitivity, we examined effects on cellular anticancer drug sensitivities of transfections with 5 different specific DAPK small-interfering RNAs (siRNAs) into HHUA cells. DAPK siRNA transfections strongly enhanced 5-fluorouracil (5FU)-sensitivity, but not etoposide-sensitivity, of HHUA cells compared with control siRNA-transfected cells. These results indicate that etoposide-stimulated cell death signals may share or include TRAIL-mediated apoptotic signals, and that 5FU-stimulated cell death signals may be independent from TRAIL-mediated apoptotic signals induced by DAPK siRNA transfections. Moreover, 5FU-combined chemotherapy with DAPK siRNA transfection may show stronger anticancer effects on patients with endometrial adenocarcinoma than does chemotherapy alone.

Death-associated protein kinase is essential for the survival of various types of uterine cancer cells.

We recently showed that targeted knockdown of death-associated protein kinase (DAPK) expression induces apoptosis in the human endometrial adenocarcinoma cell line HHUA. To investigate the possibility that DAPK may represent a molecular target for anticancer therapies for advanced uterine cancers, we examined the effects of DAPK siRNA transfections on the viability of five different human uterine cancer cell lines. The five uterine cell lines comprised three differentiated endometrial adenocarcinomas, one leiomyosarcoma and one carcinosarcoma. Cell death assays showed that the DAPK siRNA transfection significantly increased the cell death in all five uterine cancer cells examined. Ribonuclease protection assays did not show any remarkable changes in the bcl-2 family gene expressions after the DAPK siRNA transfection in HHUA cells. Since DAPK-mutant mice were reported to be fertile and do not show lethality, DAPK may play a central role in the immortalization and carcinogenesis of uterine cancer cells, possibly without bcl-2 family-related apoptotic regulation. These results indicate that DAPK can be a convincing candidate for molecularly targeted anticancer therapies for patients with various types of advanced uterine cancers, including carcinosarcoma and leiomyosarcoma.

Establishment and characterization of monoclonal 5-fluorouracil-resistant cell lines derived from human endometrial adenocarcinoma.

To investigate acquired 5-fluorouracil (5FU)-resistance in cancer cells, we established four monoclonal 5FU-resistant cell lines from human endometrial adenocarcinoma cells by long-term 5FU-exposure cultures and limiting dilution cultures. The established subclones exhibited 5-25 times greater 5FU-resistance than the parent cells, and showed suppression of 5FU-induced DNA fragmentation. All four 5FU-resistant subclones were 25-125 times more resistant to SN38, 4-hydroxy-cyclophosphamide, paclitaxel and etoposide than the parent cells while none of the four subclones showed resistance to mitomycin. Two of the four subclones showed no resistance to pirarubicin and bleomycin. Although all four 5FU-resistant subclones were 5-25 times more resistant to anti-Fas IgM than the parent cells, the resistance levels to anti-Fas IgM of the individual subclones did not coincide with the strengths of their multidrug resistance. Karyotyping analyses revealed that the parent cells and the three 5FU-resistant subclones examined had normal 46XX karyotypes. These results indicate that the cell death signals induced by mitomycin, pirarubicin and bleomycin are distinctly different from the Fas-mediated apoptotic signals, that acquisition of 5FU-resistance can occur without any large chromosomal deletions or rearrangements, and that there are several possible molecular changes during the acquisition of 5FU-resistance. The established cell lines represent useful tools for investigating the mechanisms and treatments of acquired 5FU-resistance.

Establishment and characterization of novel human uterine leiomyosarcoma cell lines.

Patients with unresectable advanced uterine leiomyosarcoma have a very poor prognosis because no effective chemotherapeutic protocols exist. There are currently few established primary human uterine leiomyosarcoma cell lines that can be used to investigate effective therapies. To overcome this problem, we carried out long-term in vitro cell culture and/or nude mouse transplantation and successfully established novel human uterine leiomyosarcoma cell lines from extrauterine and intrauterine tumors that were surgically excised from a single patient. The established cells were characterized by flow cytometry, anticancer drug-sensitivity assays and karyotyping analyses. All the established cell lines showed unstable multiple chromosome abnormalities. Since the cells can proliferate in vitro and in vivo, they will be useful for developing new therapeutic strategies for advanced uterine leiomyosarcoma patients.

Targeted knockdown of death-associated protein kinase expression induces TRAIL-mediated apoptosis in human endometrial adenocarcinoma cells.

Death-associated protein kinase (DAPK) is a serine/threonine kinase that participates in the modulation of apoptosis and tumor suppression. Our previous study revealed high levels of DAPK protein expression in differentiated endometrial adenocarcinoma cells. To clarify the role of DAPK in human endometrial adenocarcinomas, we down-regulated endogenous DAPK expression in HHUA cells, a well-differentiated endometrial adenocarcinoma cell line, using specific small-interfering RNAs (siRNAs). The suppression of endogenous DAPK expression triggered apoptosis in HHUA cells, as evidenced by an increase in the sub-G1 DNA content in flow cytometric analyses. The apoptosis induced by the DAPK siRNA transfections was caspase-dependent, as characterized by the activations of caspase-3, -8 and -9. RNase protection assays detected higher levels of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), DR4 and DR5 transcripts in the DAPK siRNA-transfected HHUA cells than in the control siRNA-transfected cells. Consistent with these findings, enzyme-linked immunosorbent assays revealed that the DAPK siRNA transfections significantly increased the secretion of TRAIL protein from the cells. Treatment with recombinant human TRAIL protein dose-dependently suppressed the cell viability of HHUA cells. The present findings reveal that down-regulation of endogenous DAPK expression in HHUA cells induces caspase-dependent apoptosis, possibly through increased TRAIL, DR4 and DR5 signaling, thereby suggesting that DAPK expression is essential for HHUA cell survival. Consequently, endogenous DAPK mRNA may represent a potential candidate for molecularly targeted anticancer therapies.

Deletion of Sema4D gene reduces intimal neovascularization and plaque growth in apolipoprotein E-deficient mice.

Neovascularization occurring in atherosclerotic plaque leads to acceleration of plaque growth through increased leukocyte infiltration and reactive oxygen species (ROS) production. Sema4D (CD100), a class IV semaphorin, not only plays a crucial role in axon guidance but also functions in the neovascularization process of tumor growth. To clarify the roles of Sema4D in the progression of atherosclerosis and neovascularization of atherosclerotic plaque, we analyzed the effect of Sema4D gene deletion from apolipoprotein E (ApoE)-deficient mice in the development of atherosclerosis. Lipid staining demonstrated significant decreases in plaque areas in the aortas of 6-month-old Sema4D-/- ApoE-/- mice compared with 6-month-old ApoE-/- mice. Thus, the Sema4D gene knockout in ApoE-deficient mice was found to slow the progression of atherosclerosis. Immunohistochemical analyses confirmed the expression of Sema4D protein in infiltrating lymphoid cells in atherosclerotic plaque and plexin-B1 receptor in neovascular endothelial cells within the plaque. Furthermore, there were significant decreases in the degree of neovascularization in the plaque areas of Sema4D-/- ApoE-/- mice compared with ApoE-/- mice as revealed by both isolectin B4 and CD31 staining. The number of infiltrating macrophages in Sema4D-/- ApoE-/- mice plaques was also significantly less than those in ApoE-/- mice. These findings suggest that Sema4D is involved in the progression phase of atherosclerosis by accelerating intimal neovascularization, resulting in enhanced macrophage infiltration in atherosclerotic plaques.

Use of 18F-fluorodeoxyglucose positron emission tomography for diagnosis of uterine sarcomas.

We evaluated the use of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) for the diagnosis of uterine sarcomas. FDG-PET combined with serum lactate dehydrogenase (LDH) levels were compared with FDG-PET alone for the diagnosis of leiomyosarcomas (LMS), which are the most difficult uterine sarcomas to diagnose. FDG-PET imaging of endometrial cancer (EC) was used as a reference. Immunoreactivity for glucose transporter-1 (GLUT-I) correlated with FDG uptake was evaluated in sarcomas and leiomyomas (LM), including cases not examined by FDG-PET. FDG was injected after at least 5 h fasting and standardized uptake values (SUVs) were analyzed quantitatively 50-70 min after injection. Immunohistochemical expression of GLUT-1 was studied in paraffin sections of tumors using anti-GLUT-1 antibodies and GLUT-1 expression scores were derived based on staining intensities. FDG-PET was performed preoperatively in a total of 53 patients including 10 with sarcomas, 19 with EC and 24 with LM. Immunohistochemical examination was performed in 17 sarcomas, 6 EC and 9 LM [6 usual LM, 1 uterine smooth muscle tumor of uncertain malignant potential (UMP), and 2 bizarre LM (BLM)]. SUVs for uterine sarcomas and EC were significantly higher (p=0.0001) than those for LMs. There were no significant differences in SUVs among ECs, carcinosarcomas (CS) and LMS. Significant differences in SUVs existed between LM and LMS (p=0.003). However, the diagnostic accuracy for LMS was only 73%. The diagnostic accuracy of FDG-PET combined with serum LDH was 100%. GLUT-1 expression scores were significantly higher in sarcomas and EC than in LM (p<0.0001). Intermediate GLUT-1 scores were found in two of the three cases of UMP and BLM. In conclusion, FDG-PET is useful for diagnosing uterine sarcomas, while FDG-PET combined with serum LDH is useful for diagnosing LMS. Immunohistochemical examination of GLUT-1 confirmed the high FDG uptake in LMS patients.

Sema4A induces cell morphological changes through B-type plexin-mediated signaling.

Semaphorins are a family of secreted and membrane-bound proteins known as axonal pathfinders. Sema4A, a member of class 4 semaphorins, induces growth cone collapse of hippocampal neurons. The binding of Sema4A to growth cones indicates the presence of receptors transmitting signals through the intracellular effectors to induce growth cone collapse in hippocampal neurons. Transfection experiments of the candidate receptor genes into COS-7 cells demonstrated that Sema4A binds to axonal guidance receptors Plexin-B1, -B2 and -B3. To identify the functional Sema4A receptor and the signal transduction machinery, COS-7 cell contraction assay was performed, in which intracellular signal transmission induced by Sema4A triggered cell contraction. Expression vectors encoding plexins and Rnd1, a Rho family GTPase, were transfected into COS-7 cells, and a proportion of contracted cells among the transfectants was determined after incubation with Sema4A. The results demonstrated that the combination of Rnd1 and Plexin-B1, -B2 or -B3 induced significant cell contraction, indicating that B-type plexins transmit an intracellular signal of Sema4A through Rnd1. To further study the mechanism of B-type plexin-mediated signaling in Sema4A-induced growth cone collapse, mouse hippocampal neurons transfected with a control or expression plasmid encoding a constitutively active mutant of R-Ras (R-RasQL) were stimulated with Sema4A, followed by the assessment of growth cone collapse. Expression of R-RasQL significantly blocked Sema4A-induced growth cone collapse in the hippocampal neurons compared with the control plasmid. Sema4A thus induces growth cone collapse through the down-regulation of R-Ras activity in mouse hippocampal neurons.