Comparison of antitumor effects of multitargeted tyrosine kinase inhibitors in acute myelogenous leukemia

We compared the antitumor activities of the multitargeted tyrosine kinase inhibitors imatinib, sorafenib, and sunitinib to determine which inhibitor is best suited to be used for the treatment of acute myelogenous leukemia (AML). In nine human AML cell lines, sorafenib and sunitinib were more potent inhibitors of cellular proliferation than imatinib (IC50, 0.27 to >40, 0.002-9.1, and 0.007-13 micromol/L for imatinib, sorafenib, and sunitinib, respectively). Sorafenib and sunitinib were potent inhibitors of cells with fms-like tyrosine kinase 3 internal tandem duplication (IC50, 2 and 7 nmol/L) and c-KIT N822K mutations (IC50, 23 and 40 nmol/L). In four cell lines (MV4-11, Kasumi-1, KG-1, and U937) that spanned a range of drug sensitivities, sorafenib and sunitinib had similar activity in apoptosis and cell cycle assays, except that sunitinib did not promote apoptosis in U937 cells. Both drugs inhibited mitogen-activated protein kinase signaling but had no effect on AKT signaling in most of the cell lines tested. Sorafenib was substantially more bound than sunitinib in human plasma (unbound fraction, 0.59% versus 8.4%) and cell culture medium (unbound fraction, 1.3% versus 39%), indicating that sorafenib was more potent than sunitinib and that unbound sorafenib concentrations with activity against most AML cell lines are achievable in vivo. There was more intracellular accumulation of sorafenib than of sunitinib and imatinib in AML cells. Between 1 and 10 micromol/L, sorafenib inhibited the proliferation of six of nine primary AML blast samples by > or =50%. Our results highlight the pharmacologic features of sorafenib that may provide it an advantage in the treatment of AML.

Pulmonary alveolar proteinosis in pediatric leukemia

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare disorder characterized by intra-alveolar accumulation of periodic acid-Schiff (PAS)-positive surfactant components. Leukemia is the cancer most often associated with PAP; prolonged neutropenia and reduction of alveolar macrophages by myeloablative chemotherapy or leukemic infiltration are implicated. Only isolated cases of PAP have been reported, and pediatric experience is limited.

PROCEDURE

We reviewed all pathology records (1962-2007) of St. Jude Children's Research Hospital to identify patients with PAP.

RESULTS

Five patients had PAP. As expected, all had leukemia and had profound neutropenia at onset of PAP. A diagnosis was made only after PAS staining of bronchoalveolar lavage (BAL), lung biopsy, or autopsy specimens. Two patients had Down syndrome, which is not known to be associated with PAP. The other three patients had undergone hematopoietic stem cell transplantation (HSCT). Two patients showed clinical improvement or histological disappearance of PAP after neutropenia resolved.

CONCLUSIONS

PAP should be considered in the differential diagnosis of severe respiratory symptoms in neutropenic patients with hematologic malignancy, especially those with Down syndrome, a history of HSCT, or active disease. PAP should be confirmed by PAS staining of a BAL or lung biopsy specimen.

Distribution of Porphyromonas gingivalis fimA genotypes in cardiovascular specimens from Japanese patients

INTRODUCTION

Porphyromonas gingivalis, a major periodontal pathogen, is gaining increasing attention for its possible association with cardiovascular diseases. Its fimbriae are classified into six genotypes (types I-V and Ib) based on the diversity of the fimA genes encoding the fimbrial subunits. In this study, fimA genotypic distribution was analyzed in P. gingivalis-infected cardiovascular specimens.

METHODS

A total of 112 heart valves and 80 atheromatous plaque specimens were collected from patients undergoing cardiovascular surgery, as well as 56 dental plaque specimens. Bacterial DNA was extracted from each, and polymerase chain reaction analysis was carried out with a P. gingivalis-specific set of primers. P. gingivalis-positive specimens were further analyzed to discriminate the fimA genotype using polymerase chain reaction with fimA type-specific primer sets.

RESULTS

P. gingivalis was detected in 10.4% of the cardiovascular specimens and 50.0% of the dental plaque samples. In the latter, type II was most frequently detected (35.7%), followed by types I (28.6%) and IV (21.4%), while types IV and II were detected with considerable frequencies of 45.0% and 30.0%, respectively, in the cardiovascular specimens. In contrast, the occurrence of type I was limited (5.0%) in the cardiovascular specimens.

CONCLUSION

These results suggest that specific fimA genotypic clones, which are reportedly associated with periodontitis, are also frequently harbored in cardiovascular specimens, indicating the possible involvement of type II and IV clones in the initiation and progression of cardiovascular diseases.

Porphyromonas gingivalis gingipains cause G(1) arrest in osteoblastic/stromal cells

INTRODUCTION

The program for mammalian cell growth and division consists of four successive phases; G(1), S, G(2), and M. Porphyromonas gingivalis may manipulate the host cell cycle to benefit bacterial virulence expression, which likely causes the cell and tissue tropism observed in chronic periodontal infections. We examined P. gingivalis for its effects on cell-cycle modulation in mouse ST2 osteoblastic/stromal cells.

METHODS

Synchronized ST2 cells were infected with P. gingivalis ATCC33277 (wild-type, WT), gingipain-mutants [KDP136 (DeltargpADeltargpBDeltakgp), KDP129 (DeltargpADeltargpB), and KDP133 (Deltakgp)], and a fimbria-deficient mutant (KDP150) for 24 h, then the cell cycle was evaluated using flow cytometry. Cell-cycle-related molecule expression was examined with a microarray, as well as with quantitative real-time polymerase chain reaction and Western blotting assays.

RESULTS

Both the WT and KDP150 strains significantly inhibited cellular proliferation and arrested the cell cycle in the G(0)/G(1) phase, while the expression levels of the cell-cycle regulatory molecules cyclin D and cyclin E were also decreased. In contrast, KDP136 did not show any effects. G(1) arrest was also clearly induced by KDP129 and KDP133, with KDP129 being more effective.

CONCLUSION

The present findings suggest that P. gingivalis gingipains reduce cyclin expression and cause early G(1) arrest, leading to the inhibition of cellular proliferation.

Heterogenic virulence and related factors among clinical isolates of Porphyromonas gingivalis with type II fimbriae

BACKGROUND/AIMS

Porphyromonas gingivalis is a periodontal pathogen whose fimbriae are classified into six genotypes (types I-V and Ib) based on the diversity of the fimA genes encoding the fimbrial subunits. Accumulated evidence suggests that P. gingivalis strains with type II fimbriae are more virulent as compared to those with other types. However, it is unknown if strong virulence is uniformly conserved among clones with type II fimbriae. In the present study, we compared infectious inflammatory changes in clinical isolates of P. gingivalis with type II fimbriae using a mouse abscess model to examine their pathogenic heterogeneity and heterogeneity-related factors.

METHODS

Suspensions of nine different clinical isolates with type II fimbriae were subcutaneously injected into female BALB/c mice and inflammatory parameters, such as serum sialic acid concentration, were compared.

RESULTS

Many of the type II fimbrial isolates caused severe inflammation in the mice, though some were less causative, as was the control strain ATCC 33277 (type I fimbria strain). These results showed that pathogenic heterogeneity exists among P. gingivalis clones with type II fimbriae. Further, the heterogeneity-related factors of P. gingivalis strains were analyzed and the pathogenic potentials showed positive relationships to gingipain activities and invasive efficiency but not to hydrophobicity or autoaggregation. In addition, invasive efficiency was related to the activities of gingipains that were extracellularly secreted.

CONCLUSION

These results suggest that pathogenic heterogeneity has relationships with the invasive and proteolytic activities of P. gingivalis clones with type II fimbriae.

BK virus-induced tubulointerstitial nephritis in a child with acute lymphoblastic leukemia

We report a case of BK virus-induced tubulointerstitial nephritis in a child with acute lymphoblastic leukemia. Primary BK virus infection was exacerbated by chemotherapy-induced immunodeficiency. Careful administration of chemotherapy and anti-viral therapy prevented further damage. This diagnosis should be considered in children who experience renal dysfunction during cancer treatment.

Detection and serotype distribution of Actinobacillus actinomycetemcomitans in cardiovascular specimens from Japanese patients

Actinobacillus actinomycetemcomitans, an important pathogen in periodontitis, has also been detected in cardiovascular tissues. Sixty heart valves were collected during valve replacement surgery from 60 patients (one from each), 10 were from patients with infective endocarditis (IE group) and 50 were from patients with other valvular diseases (non-IE group). In addition, 46 samples of aneurysmal tissue were taken from 46 patients with a thoracic or abdominal aneurysm (Aneurysm group, one from each). Dental plaque samples were taken from 54 of the patients, 31 in the IE and non-IE groups and 23 in the aneurysm group. First, the distribution of A. actinomycetemcomitans in all specimens was analysed using a polymerase chain reaction method, which resulted in a positive reaction in 33 (31.1%) of the cardiovascular specimens and 25 (46.3%) of the dental plaque samples. Next, using serotype-specific sets of primers, the serotype distribution of A. actinomycetemcomitans in the cardiovascular specimens and dental plaque samples was found to be significantly different compared to dental plaque samples from Japanese subjects reported previously.

Diagnostic challenge in recurrent skin rash after autologous bone marrow transplantation

Engraftment syndrome, autologous graft-versus-host disease (GVHD), and infection after autologous hematopoietic cell transplantation can have similar clinical presentations. Here, we describe a patient with refractory Ewing sarcoma who had recurrent skin rash after autologous hematopoietic cell transplantation. Although the rash was diagnosed as GVHD histologically, this case illustrates the diagnostic dilemma of distinguishing engraftment syndrome, autologous GVHD, or concomitant viral infection. Because therapy for these entities is different, distinguishing them is important. Establishment of diagnostic criteria and understanding of the pathophysiology of these entities may lead to better management and to improved therapy of refractory cancer.

Displacement metrology with sub-pm resolution in air based on a fs-comb wavelength synthesizer

We report on a displacement metrology setup that provides sub-pm resolution in air. The setup is based on a Fabry-Perot cavity. However, unlike current Fabry-Perot cavity based displacement setups we incorporate a novel fs-laser based arbitrary wavelength synthesizer that provides efficient suppression of atmospheric disturbances while providing very wide and precise tuning of the output wavelength. The wavelength synthesizer provides sub-10 attometer wavelength resolution. The setup provides subpm length stability for integration times of up to one minute and sub-10 pm for up to half an hour without airtight enclosure of the Fabry-Perot cavities.

Defective cell cycle induction by IL-2 in naive T-cells antigen stimulated in the presence of refractory T-lymphocytes

CD4+ T cells enter a transient refractory period after stimulation. Upon re-stimulation the refractory cells produce little IL-2 and show diminished proliferation. We previously demonstrated that refractory T cells can also, like anergic and CD4+CD25+ regulatory T cells, suppress in trans the proliferation of antigen-stimulated naive T cells. The suppressed T cells up-regulate high-affinity IL-2R but do not produce IL-2. This IL-2 deficit could potentially explain the proliferation failure, but does not appear to do so. Supplementation of refractory-naive co-cultures with exogenous IL-2 fails to alleviate both the proliferation suppression and IL-2 production defects. This does not result from a failure of IL-2 to stimulate its receptor. Proximal IL-2 signaling into suppressed T cells through STAT5 and Akt is intact. However, refractory cell-co-cultured T cells fail to up-regulate cyclins and c-myc and incompletely down-regulate p27kip1 in response to IL-2, and the downstream consequences of this signaling are therefore dissociated. IL-2 signaling is not fully disabled as IL-2 up-regulates the anti-apoptotic protein Bcl-xL to control levels. This up-regulation correlates with enhanced survival of refractory cell-co-cultured T cells placed in IL-2 when compared with cells cultured without IL-2. Thus, refractory T cells are able to suppress naive T-cell proliferative responses in part by blocking both IL-2 production and the mitogenic but not anti-apoptotic effects of IL-2. These results have implications for how activation-refractory T cells may influence nascent immune responses.

Allogeneic graft-versus-hepatoblastoma effect

Although the survival rate for pediatric patients with hepatoblastoma has improved, prognosis is still poor when the disease is unresectable and refractory to chemotherapy. Therefore, novel approaches are warranted. Herein, we describe a patient with recurrent metastatic hepatoblastoma who received a non-myeloablative hematopoietic stem cell transplantation from an HLA-matched unrelated donor. After withdrawal of immunosuppressant and establishment of full donor T-cell engraftment, the tumor regressed and serum alpha-fetoprotein level decreased in concurrence with the onset of graft-versus-host disease (GVHD). Her disease recurred when GVHD resolved. This patient's clinical course provides evidence for the probable existence of allogeneic graft-versus-hepatoblastoma effect.

Effect of phenytoin on collagen accumulation by human gingival fibroblasts exposed to TNF-alphain vitro

OBJECTIVE

Tumor necrosis factor (TNF)-alpha is associated with chronic gingival inflammation and reported to induce gingival overgrowth (GO), while phenytoin (PHT) is also known to be a causative agent of GO. We examined the synergistic effect of PHT and TNF-alpha on collagen metabolism in human gingival fibroblasts (HGFs).

MATERIALS AND METHODS

HGFs were cultured with TNF-alpha and PHT. Quantitative real-time RT-PCR was employed to determine the mRNA levels for collagen, matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and integrin subunits. Cellular collagen endocytosis was determined using a flow-cytometry.

RESULTS

The proliferation of HGFs was not affected by TNF-alpha or PHT individually, whereas both synergistically increased collagen accumulation in HGFs. Further, collagen mRNA expression was not increased by TNF-alpha or PHT, although together they markedly prevented cellular collagen endocytosis, associated with the suppression of alpha2beta1-integrin mRNA expression. The mRNA expression of MMP-1 and-2 was suppressed by PHT, while TIMP-1 mRNA expression was enhanced by both TNF-alpha and PHT.

CONCLUSION

Our results suggest that TNF-alpha and PHT together cause impaired collagen metabolism by suppression of enzymatic degradation with MMPs/TIMP-1 and integrin-mediated endocytosis. These synergistic effects may also be involved in TNF-alpha- and PHT-induced collagen accumulation, leading to GO.

A tubular bioreactor for high density cultivation of microorganisms

By simulating the functions of the animal intestine, the authors have developed a novel tubular bioreactor (TBR) which is capable of containing both the reaction and separation of products in a single system. This reactor consisted of inorganic ultra filtration membrane modules in the primary part of the system, a heat exchanger and a recycling pump. The operation characteristics of the TBR were studied by cultivating Lactobacillus casei at a laboratory scale. The cell density obtained was up to 10 times higher than the density obtained by using the conventional jar fermentor. Furthermore, 40 g l-1 of cell mass was obtained in only 14 hours with 20 l of fresh medium when the dilution rate was increased according to the cellular growth. Afterwards, the cultivation time and the volume of fresh medium were reduced to 44% and 74%, respectively, of the values in the cultivation operation at constant dilution rate.

Phase-locked widely tunable optical single-frequency generator based on a femtosecond comb

We present an arbitrary optical single-frequency generator based on a femtosecond optical frequency comb. The functions of this device are comparable to those of a radio-frequency synthesizer. However, this device operates at hundreds of terahertz. The absolute frequency accuracy of this synthesizer is approximately 1 kHz at a 282 THz carrier frequency. The stability is approximately 2 x 10(-14) at 100 s, and the tuning speed exceeds 30 GHz/s. This source demonstrates the integration of a phase-locked optical comb into a versatile and easy-to-use system for the generation of tunable, absolute optical frequencies. By using downconversion, one could generate tunable terahertz frequencies that are phase locked to a microwave reference, such as a Cs atomic clock, and high-precision interferometry could benefit greatly from the stability and accuracy of this widely tunable source.

Acquisition of Fas resistance by Fas receptor mutation in a childhood B-precursor acute lymphoblastic leukemia cell line, MML-1

Programmed cell death, or apoptosis, is a physiological means of eliminating unwanted cells and maintaining immune homeostasis. One of the primary mechanisms is the Fas (CD95)/Fas ligand system. Its inactivation in normal cells and malignant cells may be involved in malignant trans-formation and refractory clinical course, respectively. We established a Fas resistant clone and evaluated the molecular basis for its mechanism of resistance. The Fas-sensitive leukemia cell line, MML-1, was established from a child with B-precursor acute lymphoblastic leukemia. A Fas resistant clone, MML-1R, was obtained by co-culture selection with anti-Fas antibody CH-11. Flow cytometry analysis showed both cell lines had equivalent expression of cell surface CD13, 15, 19, 22 and Fas receptor. Western blot analysis revealed equal expression of FADD (Fas-associated death domain protein), caspase-3 and -8. MML-1 was quite sensitive to both CH-11 and etoposide-induced apoptotis. By contrast, MML-1R had similar sensitivity to etoposide but no response to CH-11. Fas receptor mutation analysis showed a heterozygous death domain A --> G point mutation at 1009 bp, causing a switch from glutamine to glycine at amino acid 256. Immunoprecipitation assay showed decreased binding of Fas to FADD. We also found that etoposide bypassed Fas-FADD interaction in MML-1R by activating caspase-8 and caspase-3. These results indicate that Fas resistance can result from mutations of the gene encoding the Fas receptor which result in decreased FADD binding, thereby blocking formation of the death inducing signaling complex. Screening for similar Fas mutations in therapy resistant malignancies would lead to a better understanding of tumorigenesis and recurrence.

A case of hemoglobin SC disease with cold agglutinin-induced hemolysis

Children with sickle cell disease commonly require red blood cell (RBC) transfusion. We report the first case of hemoglobin (Hb) SC disease with development of severe anemia induced by cold agglutinin hemolysis after Mycoplasma infection. Complete blood count (CBC) showed falsely decreased RBC count and hematocrit and falsely elevated MCV and MCHC. Peripheral blood smear showed RBC clumping at room temperature; this disappeared after warming to 37 degrees C. Anti C3b-C3d was present on red cells, and indirect antiglobulin test revealed a circulating cold agglutinin. Furthermore, anti-Mycoplasma pneumoniae IgM antibody was detected in serum. Careful evaluation of CBCs and peripheral blood smears is required in cases of worsening anemia among sickle cell patients and consideration should be given to cold hemagglutinin disease as an etiology.

Interferon-gamma sensitizes osteosarcoma cells to Fas-induced apoptosis by up-regulating Fas receptors and caspase-8

BACKGROUND

Osteosarcoma is the third most frequent neoplasm in adolescents. Although chemotherapy, frequently used in pre- and post-operative settings, has resulted in significant improvement in disease-free survival, some patients show little sensitivity to chemotherapy and alternative therapeutic strategies are needed. Because the Fas ligand/Fas receptor (CD95, APO-1) apoptosis pathway is a potential therapeutic target in osteosarcomas, we examined the effect of IFN-gamma on Fas-induced apoptosis in four osteosarcoma cell lines.

PROCEDURE AND RESULTS

As measured by flow cytometry, all cell lines expressed cell surface IFN-gamma receptors, and when cultured for 2 days in the presence of IFN-gamma, all cell lines exhibited a significant increase in expression of Fas receptors. By flow cytometric detection of intracellular fragmented DNA as a marker of apoptosis, all cell lines cultured with either IFN-gamma or anti-Fas antibody (clone CH-11) alone showed only moderate apoptosis, whereas significantly high levels of apoptosis occurred in cells cultured with both IFN-gamma and CH-11. Western blotting analysis also revealed that IFN-gamma caused up-regulation of caspase-8 in all cell lines, but no change in Fas-associated death domain protein (FADD/MORT1) or caspase-3. Both caspase-8 and caspase-3 were activated when apoptosis was induced with both IFN-gamma and CH-11. Addition to cultures of z-IETD-fmk, an inhibitor of caspase-8, significantly blocked this apoptosis.

CONCLUSIONS

IFN-gamma sensitizes osteosarcoma cells to Fas-induced apoptosis through up-regulation of Fas receptor and caspase-8. Combined immunotherapy with IFN-gamma and either anti-Fas monoclonal antibody or cytotoxic T cells that bear Fas ligand might be a useful adjunctive therapy for patients with osteosarcoma.

Frequency metrology with a turnkey all-fiber system

The repetition rate and carrier-envelope phase offset frequencies of a turnkey, all-fiber-based continuum generator were phase locked to a hydrogen maser. The frequency of the hydrogen maser was calibrated with a highly stable cesium atomic clock, and therefore a fully phase-locked optical frequency comb with well-defined absolute frequencies was obtained. In contrast with the commonly used Ti:sapphire-laser-based systems, we have accomplished a fully turnkey system with no user-adjustable parts. To evaluate the performance of this novel system, we performed absolute frequency measurements in the telecommunications region and at 1064 nm and compared them with our traditional Ti:sapphire-based comb.

C-terminal peptides of p53 molecules enhance radiation-induced apoptosis in human mutant p53 cancer cells

We propose here a novel p53-targeting radio-cancer therapy using p53 C-terminal peptides for patients having mutated p53. Hoechst 33342 staining showed that X-ray irradiation alone efficiently induced apoptotic bodies in wild-type p53 (wt p53) human head and neck cancer cells transfected with a neo control vector (SAS/neo cells), but hardly induced apoptotic bodies in mutation-type p53 (m p53) cells transfected with a vector carrying the m p53 gene (SAS/m p53). In contrast, transfection of p53 C-terminal peptides (amino acid residues 361-382 or 353-374) via liposomes caused a remarkable increase of apoptotic bodies in X-ray-irradiated SAS/m p53 cells, but did not enhance apoptotic bodies in X-ray-irradiated SAS/neo cells. In immunocytochemical analysis, positively stained cells for active type caspase-3 were observed at high frequency after X-ray irradiation in the SAS/m p53 cells pre-treated with p53 C-terminal peptides. In SAS/neo cells, positively stained cells for active type caspase-3 were observed with X-ray irradiation alone. Furthermore, protein extracts from X-ray-irradiated SAS/m p53 cells showed higher DNA-binding activity of p53 to p53 consensus sequence when supplemented in vitro with p53 C-terminal peptides than extracts from non-irradiated SAS/m p53 cells. These results suggest that radiation treatment in the presence of p53 C-terminal peptides is more effective for inducing p53 -mediated apoptosis than radiation treatment alone or p53 C-terminal peptide treatment alone, especially in m p53 cancer cells. This novel tool for enhancement of apoptosis induction in m p53 cells might be useful for p53-targeted radio-cancer therapy.

[Schwannoma of the recurrent laryngeal nerve; report of a case]

A 57-year-old woman was admitted to our hospital because of an abnormal shadow on her chest X-ray film and a palpable left neck mass. She had a mild cough. Computed tomography (CT) scans and magnetic resonance imaging (MRI) of the chest demonstrated a well-circumscribed, huge mass (approximately 14 cm in diameter) in the left anterior mediastinum. On June 12th, 2000, the mass was resected. During surgery, the tumor seemed to arise from the left recurrent laryngeal nerve. The pathological examination revealed the tumor as a schwannoma. Recurrent laryngeal nerve schwannoma is extremely rare.

[Anterior cervical approach for resection of brachial plexus schwannoma expanding into the thoracic apex]

Primary tumors of the brachial plexus are unusual. We describe 2 patients with schwannomas of the brachial plexus that had the radiologic appearance of apical lung masses. We used anterior cervical approach for both of the patients. Our technique permitted safe and complete resection of the tumors of this complex area. Both tumors were arising from the Th1 component of brachial plexus. Histopathological findings revealed that both of the tumors were benign schwannomas. This approach is quick and safe, allowing much better control of the important vascular and neural structures of the thoracic apex. Tumors at the area are inaccessible by using posterolateral thoracotomy or video-assisted thoracic surgery. We suggest that the anterior cervical approach would be applied for the resection of other kind of tumors in the thoracic apex.

Herpes simplex virus pneumonia in a patient with ependymoma

The authors report a fatal outcome in a 4-year-old boy with herpes simplex virus (HSV) pneumonia and ependymoma. The patient had respiratory distress that worsened despite antibiotic treatment. Bronchoalveolar lavage showed intranuclear viral inclusions, and culture was positive for HSV type 1. His T-cell count was significantly decreased. Although acyclovir and foscarnet were given, the patient died. Postmortem examination showed HSV pneumonitis with severe alveolar damage and severe involutional changes of the thymus with absence of Hassall's corpuscles. HSV must be considered in the differential diagnosis of patients with interstitial pneumonia and T-cell deficiency, especially after craniospinal irradiation.