Synthesis and antiviral activity of novel derivatives of 2'-beta-C-methylcytidine

A series of novel derivatives of 2'-C-beta-methylcytidine, involving nucleosides modified in the "upper part" of the pyrimidine base (N(4)- and/or 5-position), has been synthesized and evaluated for their inhibitory effect on in vitro replication of the hepatitis C virus and the yellow fever virus (both Flaviviridae).

Synthesis and antiviral evaluation of 2'-C-methyl analogues of 5-alkynyl- and 6-alkylfurano- and pyrrolo[2,3-d]pyrimidine ribonucleosides

A series of novel 2'-C-methylribonucleosides, involving 5-iodo and 5-alkynyl uridine analogues as well as related bicyclic furano- and pyrrolo[2,3-d]pyrimidinone compounds, has been synthesized and evaluated for their inhibitory effect on replication of the hepatitis C virus (HCV). The new nucleoside analogues did not show meaningful anti-HCV activity.

Non-sentinel lymph node status and prognosis of the breast cancer patients with micrometastatic sentinel lymph nodes

e11504

Background: Sentinel lymph node biopsy (SLNB) has become a standard therapy for clinically node-negative breast cancer patients and improvements of histopathological and molecular analysis of sentinel lymph node (SLN) have increased the rate of micrometastases identified. However it remains controversial whether to perform axillary lymph node dissection (ALND) for patients with micrometastases in SLNs and their prognostic significance is also a matter of debate. The purpose of this study is to determine the non- sentinel lymph node (NSLN) status and prognosis of the patients with micrometastatic SLNs. Methods: A prospective database of 666 breast cancer patients with the tumor size less than 3cm and clinical negative node, who underwent SLNB from January 2002 to July 2007 at Keio University Hospital was analyzed. SLNs were detected using a combined method of isosulfun blue dye and small-sized technetium-99m-labeled tin colloid. SLNs were diagnosed with standard hematoxylin and eosin (HE) staining and immunohistochemical (IHC) analysis. Results: Micrometastases in SLNs were found in 50 (7.5%) of 666 patients. Twenty nine (58.0%) of 50 patients with micrometastatic SLNs underwent ALND and revealed no NSLN metastasis. Among 21 (42.0%) patients with micrometastatic SLNs who skipped ALND, no axillary lymph node recurrence has been observed in the median follow-up time of 43 months, although 20 patients (95.2%) in 21 patients received adjuvant systemic therapy. There is no significant difference in recurrence free survival between the patients with micrometastatic and negative SLNs (98.0% vs. 95.7%, respectively). Conclusions: These date suggested that it may not be necessary to perform ALND for the patients with micrometastases in SLNs and the presence of micrometastases in SLNs may not be associated with prognosis.

No significant financial relationships to disclose.

Long-term treatment with intravenous bisphosphonates in metastatic breast cancer (MBC)

1035

Background: Intravenous bisphosphonates (IV BPs) are safe and effective in reducing skeletal related events in MBC. The effects of IV BPs after 24 months of therapy are unknown. The incidence of osteonecrosis of the jaw (ONJ) and renal insufficiency (RI) among women with MBC receiving >= 24 months of IV BPs is also poorly defined. We studied the long term effect of IV BPs in a cohort of women with MBC. Methods: We maintain an ongoing prospective database of >600 women with MBC diagnosed and treated at our institution from January 1999. A long-term cohort (LTC) of 159 women with metastatic breast cancer to bone treated for >= 24 months with pamidronate (n = 9), zoledronic acid (n = 110), or both (n = 40) was identified. A control cohort (CC) of 62 women with MBC to bone treated with IV BPs for 12–23 months was also identified. RI was defined as an increase in serum creatinine (scr) of > 0.5 mg/dl or an absolute level of scr >1.5mg/dl; ONJ was diagnosed by dental consultation. Results: Median follow-up of the LTC was 39 months (range 24–99) months. Median overall survival in this cohort was 43 months (range 24–114). The vast majority of women in the LTC (140/159, 88.1%) continued to receive IV BPs at standard dose every 3–4 weeks. The incidence of ONJ in the LTC was 6/159 (3.8%), after a mean 42.2 treatment cycles, with a median time to ONJ of 44 months. Three of six patients with ONJ (50%) underwent surgical resection, and 3/6 (50%) were managed conservatively, and 3/6 (50%) resumed IV BPs after a mean 12 month hold. The incidence of RI (all pts had baseline scr < 1.4 mg/dl) in the LTC was 19/159 (11.9%), occurring after a mean 43.4 treatment cycles, with a median time to RI of 43 months. Eleven of 19 patients (57.9%) recovered to baseline scr and 7/19 (36.7%) patients showed partial recovery. Seventeen of 19 patients (89.4%) were able to resume therapy after temporary discontinuation, decreasing the dose, or increasing the interval of the IV BP. Incidence of ONJ in the CC was 1/62 (1.6%) and RI in the CC was 6/62 (9.7%). Conclusions: Long term (>=24 month) IV BP use in MBC is well tolerated and safe, with relatively low incidence of ONJ and RI. Most patients were able to resume IV BP therapy after a therapy hold without further complication.

No significant financial relationships to disclose.

Studies on the conformation and interactions of elastin: nuclear magnetic resonance of the polyhexapeptide

Synthesis, proton magnetic resonance and carbon-13 magnetic resonance characterizations, including complete assignments, are reported for the polyhexapeptide of elastin, HCO-Val(Ala1-Pro2-Gly3-Val4-Gly5-Val6)18-OMe. Temperature dependence of peptide NH chemical shifts and solvent dependence of peptide C-O chemical shifts have been determined in several solvents and have been interpreted in terms of four hydrogen bonded rings for each repeat of the polyhexapeptide. The more stable hydrogen bonded ring is a beta-turn involving Ala1C-O--HN-Val4. More dynamic hydrogen bonds are an 11-atom hydrogen bonded ring Gly3NH--O-C Gly5, a 7-atom hydrogen bonded ring (a gamma-turn) Gly3 C-O--NH-Gly5, and a 23-atom hydrogen bonded ring Val6inH--O-C Val6(i+1). This set of hydrogen bonds results in a right-handed beta-spiral structure with slightly more than two repeats (approximately 2.2) per turn of spiral. The beta-spiral structure is briefly discussed relative to data on the elastic fiber.

An aspergillotic aneurysm of the internal carotid artery following allogeneic bone marrow transplantation: successful management with catheter coil embolization and long-term antifungal agents

We report a case of a mycotic aneurysm of the internal carotid artery and cerebral hemorrhagic infarction resulting from Aspergillus middle ear infection in a patient with severe aplastic anemia who received unrelated bone marrow transplantation. Although a mycotic aneurysm is a rare complication, and most often fatal, the patient was successfully treated with catheter coil embolization of the internal carotid artery and long-term systemic antifungal therapy. This case emphasizes the need for the rapid diagnosis of potential fungal involvement of the vascular system and suggests the necessity for aggressive treatment, such as with the modality illustrated in this case.

New analogs of acyclovir substituted at the side chain

A series of novel analogs of acyclovir, substituted with an alkyl (methyl, ethyl, n-butyl) or phenyl group at the positions 1', 4', and/or 5', has been obtained in a direct one-pot coupling reaction of guanosine and the respective 1,3-dioxolanes. The new acyclonucleosides were essentially inactive in antiviral (HSV, VV, VSV, HBV) evaluation in vitro.

Relationship of vitamin D with calbindin D9k and D28k expression in ameloblasts

OBJECTIVE

Calbindin D9k (CB9k) and D28k (CB28k) are intracellular soluble calcium-binding proteins, whose expressions are considered to be regulated by vitamin D. However, the amount of CB28k expression in the kidneys of vitamin D receptor-null mice was reported to be similar to that in wild type mice, suggesting no dependence on vitamin D for its expression in kidneys. In the present study, we evaluated the effects of vitamin D on the expressions of CB9k and CB28k during amelogenesis.

DESIGN

Rats fed a vitamin D-deficient diet (VD(-) rats) or a standard diet (VD(+) rats) were subjected to immunohistochemical assays using anti-CB9k and anti-CB28k anti-serum. Further, after culturing in medium containing 1,25(OH)(2)D(3) at various doses, quantitative RT-PCR analyses of CB9k and CB28k mRNA were performed using tooth germs from the lower first molars of ICR mice.

RESULTS

CB9k-immunoreactivity was detected faintly during the secretory stage of ameloblasts in the incisors of VD(+) rats, with increased staining observed during the maturation stage, whereas no such immunoreactivity was detected in those of VD(-) rats. In contrast, the distribution of CB28k in the teeth of VD(-) rats was nearly identical to that in teeth of VD(+) rats, with immunoreactivity detected in both secretory and maturation ameloblasts. Further, quantitative RT-PCR analyses revealed that the amount of CB9k mRNA was increased in a dose-dependent manner, whereas that of CB28k mRNA was not changed.

CONCLUSIONS

Vitamin D has no effect on the expression of CB28k, whereas it has a significant effect on that of CB9k in ameloblasts.

Phex mutation causes overexpression of FGF23 in teeth

OBJECTIVE

Hyp mice have a disorder in phosphate homeostasis, and display hypo-mineralization in bones and teeth, while the Phex (phosphate regulating gene homologies to endopeptidase on the X chromosome) gene in Hyp mice has a deletion of the 3' end. We investigated whether a mutation of Phex has an effect on the expression level of fibroblast growth factor 23 (FGF23), one of the key factors of phosphate homeostasis, in developing teeth of Hyp mice.

DESIGN

RT-PCR and in situ hybridisation analyses for FGF23 were performed using developing teeth of WT mice. Quantitative RT-PCR analyses for FGF23 were performed using the tooth germs of WT and Hyp mice in both in vivo and in vitro experiments.

RESULTS

Undifferentiated and early secretory ameloblasts as well as odontoblasts expressed FGF23 mRNA during early tooth development. Further, quantitative RT-PCR analyses revealed that the amount of FGF23 mRNA in Hyp mouse teeth was significantly higher than that in wild type mice.

CONCLUSIONS

These findings suggest that loss of Phex function is related to overexpression of FGF23 in teeth, which is an intrinsic defect of Hyp mouse teeth.

Phex mutation causes the reduction of npt2b mRNA in teeth

Hyp mice (murine homologue of human X-linked hypophosphatemia) have a disorder in phosphate homeostasis, and display hypomineralization in bones and teeth. We investigated whether a mutation of Phex (phosphate regulating gene homologies to endopeptidase on the X chromosome) has an effect on the expression level of type II sodium-dependent phosphate co-transporter (Npt2) in the developing teeth of the Hyp mouse. Quantitative RT-PCR analyses revealed that the amount of Npt2b mRNA, an isoform of Npt2, in Hyp mouse tooth germs was significantly lower than that in wild-type mice, in both in vivo and in vitro experiments. In addition, tooth germs from wild-type mice cultured in medium supplemented with antisense oligo-deoxynucleotide for Phex also showed a reduction of Npt2b mRNA expression. These findings suggest that the loss of Phex function is related to the defect of Npt2b expression in teeth, and Npt2b reduction is an intrinsic defect of Hyp murine teeth.

Synthesis of 6-arylthio analogs of 2',3'-dideoxy-3'-fluoroguanosine and their effect against hepatitis B virus replication

A key compound, 2-amino-6-chlor-9-(2,3-dideoxy-3-fluoro-beta-D-erythro-pentofuranosyl)puine, was prepared from 2-amino-6-chloropurine riboside in 5 steps, then subjected to the nucleophilic displacement with benzenethiols to afford 6-arylthio congeners. These compounds showed a similar anti-HBV effect to that of 2',3' dideoxy-3'-fluoroguanosine.