Synthesis and characterization of semi-interpenetrating polymer networks based on polyurethane and N-isopropylacrylamide for wound dressing

Thermosensitive semi-interpenetrating polymer networks (semi-IPNs) composed of crosslinked poly(N-isopropylacrylamide) (PNiPAAm) and linear segmented polyurethane urea (SPUU) were synthesized via thermal initiated free radical polymerization. Synthesized semi-IPNs of various compositions were characterized by Fourier transform infrared spectroscopy, water equilibrium swelling at different temperatures, drug lading, drug release, cell adhesion, and detachment. The semi-IPN films of all the compositions were transparent in dry state and negative thermosensitivity in their swelling ratio, that is, lower swelling levels with increasing temperature. The drug release study revealed that the rate of drug release is fast in case of pure SPUU compared to PNiPAAm and semi-IPN film. Drug release depended mainly on solubility of the drugs and physical networks between SPUU and PNiPAAm. Finally NIH3T3 cells were seeded on the semi-IPN films and found that cells were securely attached and proliferated to confluence. Upon cooling, cells were detached from the semi-IPN films. Therefore, the semi-IPN films may be good candidate materials for wound dressing applications.     

Induction of peptide-specific immune response in patients with primary malignant melanoma of the esophagus after immunotherapy using dendritic cells pulsed with MAGE peptides

Primary malignant melanoma of the esophagus (PMME) is a very rare disease with an extremely poor prognosis. Surgery is currently considered its best treatment, while any other measures are ineffective. We studied the effect of active specific immunotherapy using monocyte-derived dendritic cells (DCs) pulsed with the epitope peptides of melanoma-associated antigens (MAGE-1, MAGE-3) in patients with PMME after surgery, for the first time. The patient received passive immunotherapy with lymphokine-activated killer cells concomitantly. Two HLA-A24-positive patients with PMME were treated. Both patients initially received radical esophagectomy with regional lymphadenectomy, followed by adjuvant chemotherapy with dacarbazine, nimustine, vincristine and interferon-alpha. In the case 1 patient, active specific immunotherapy was used to treat a large abdominal lymph node metastasis that became obvious 21 months after surgery. The disease remained stable for 5 months, and the patient survived for 12 months after the initiation of immunotherapy. In the case 2 patient, immunotherapy was tried as post-operative adjuvant treatment after adjuvant chemotherapy. There was no tumor recurrence for 16 months after the immunotherapy. As of 49 months after esophagectomy, the patient is still alive. In both patients, the ability of peripheral lymphocytes to produce IFN-gamma in vitro in response to peptide stimulation was significantly enhanced and delayed-type hypersensitivity skin test response to MAGE-3 peptide was turned positive after immunotherapy. In conclusion, active specific immunotherapy for PMME with the use of DCs and MAGE peptides was safe and capable of inducing peptide-specific immune responses. This case report warrants further clinical evaluation of this immunotherapy for PMME.     

Effects of naphthoquinone on airway responsiveness in the presence or absence of antigen in mice

We have recently demonstrated that naphthoquinone (NQ), one of extractable chemical compounds of diesel exhaust particles (DEP), enhances antigen-related airway inflammation with goblet cell hyperplasia in mice (Inoue et al. in Eur Respir J 209(2):259–267, 2007). Further, NQ has enhanced lung expressions of interleukin (IL)-4 and IL-5. However, the effects of NQ on other cardinal features of asthma have not been completely investigated. The aim of the present study was to evaluate the effects of NQ on airway responsiveness on the model. Vehicle, NQ, ovalbumin (OVA), or NQ + OVA was administered intratarcheally to ICR mice for 6 weeks. Twenty-four hours after the last instillation, lung histology, lung functions such as total respiratory system resistance (R) and Newtonian resistance (R _n), and protein level of IL-13 and mRNA level for MUC5AC in the lung were examined. Repetitive exposure to NQ aggravated antigen-related lung inflammation. NQ alone enhanced R and R _n as compared to vehicle without statistical significance. OVA alone or NQ plus OVA showed increases in R and R _n, which was prominent in NQ plus OVA (P < 0.05 vs. vehicle). Combined exposure to NQ and OVA elevated the levels of IL-13 and MUC5AC in the lung as compared with exposure to NQ or OVA alone. These results indicate that NQ can enhance airway hyperresponsiveness in the presence or absence of an antigen. Also, amplified lung expressions of IL-13 and MUC5AC might partly contribute to the deterioration of asthma features by NQ.     

Downregulation of vasopressin V(1A) receptors and activation of mitogen-activated protein kinase in rat mesangial cells cultured under high-glucose conditions

SUMMARY: In the present study we examined the effects of high extracellular glucose concentrations on vasopressin (AVP) V(1A) receptor kinetics and signal transduction in cultured rat mesangial cells. Scatchard analysis of [(3) H]-AVP binding to mesangial cell plasma membranes showed that although high glucose (30?mmol/L) decreased V(1A) receptor numbers relative to cells cultured in normal glucose (10?mmol/L), receptor affinity was not affected. This V(1A) receptor downregulation was associated with an attenuated increase in AVP-stimulated cytosolic free calcium concentrations ([Ca(2+) ](i) ). In addition, high glucose increased both the basal and AVP-stimulated activity of the classic mitogen-activated protein kinase, namely extracellular signal-regulated kinase (ERK). Furthermore, high glucose induced activation of protein kinase C (PKC) in mesangial cells that could be inhibited by coincubation with the PKC inhibitor staurosporine (10?nmol/L). Staurosporine also markedly attenuated the high glucose-induced downregulation of V(1A) receptors on mesangial cells and blocked the depressed [Ca(2+) ](i) response and increased ERK activity induced by AVP. The results indicate that high extracellular glucose downregulates V(1A) receptors on rat mesangial cells and modulates their signal transduction properties via PKC activation.     

DNA assembly and re-assembly activated by cationic comb-type copolymer

Guanine-rich oligonucleotides, such as TG(4)T and TG(5)T, assemble into a tetramolecular quadruplexes with layers of G-quartets stabilized by coordination to monovalent cations. Association rates of the quadruplexes are extremely slow, likely owing to electrostatic repulsion among the four strands. We have shown that comb-type copolymers with a polycation backbone and abundant hydrophilic graft chains form water-soluble polyelectrolyte complexes with DNA and promote DNA hybridization. Here, we report the effect of cationic comb-type copolymers on the kinetics of tetramolecular quadruplex formation. The copolymer significantly increased the association rate of tetramolecular quadruplexes without altering kinetic effects of metal cations in quadruplex formation. Dissociation rates of the quadruplexes were also accelerated by the copolymer suggesting that the copolymer has chaperone-like activity that reduces the energy barriers associated with dissociation and re-assembly of base pairs. This hypothesis was further supported by the observation that the copolymer activated the strand exchange reaction between the quadruplex and a constituting single-stranded.     

Mouse peptidoglycan recognition protein PGLYRP-1 plays a role in the host innate immune response against Listeria monocytogenes infection

The role of mouse peptidoglycan recognition protein PGLYRP-1 in innate immunity against Listeria monocytogenes infection was studied. The recombinant mouse PGLYRP-1 and a polyclonal antibody specific to PGLYRP-1 were prepared. The mouse PGLYRP-1 showed antibacterial activities against L. monocytogenes and other Gram-positive bacteria. PGLYRP-1 mRNA expression was induced in the spleens and livers of mice infected with L. monocytogenes. The viable bacterial number increased, and the production of cytokines such as gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) was reduced in mice when mice had been injected with anti-PGLYRP-1 antibody before infection. The levels of IFN-γ and TNF-α titers in the organs were higher and the viable bacterial number was reduced in mice injected with recombinant mouse PGLYRP-1 (rmPGLYRP-1) before infection. PGLYRP-1 could directly induce these cytokines in spleen cell cultures. The elimination of intracellular bacteria was upregulated in NMuLi hepatocyte cells overexpressing PGLYRP-1. The enhancement of the elimination of L. monocytogenes from the organs was observed in IFN-γ(-/-) mice by rmPGLYRP-1 administration but not in TNF-α(-/-) mice. These results suggest that PGLYRP-1 plays a role in innate immunity against L. monocytogenes infection by inducing TNF-α.     

Mechanistic analysis of the antitumor efficacy of human natural killer cells against breast cancer cells

We investigated the role of human natural killer (NK) cells in the peripheral blood (PB) and liver in controlling breast cancer. The proportion of NK cells among liver mononuclear cells was significantly higher than among PB mononuclear cells. Liver NK cells inductively expressed higher levels of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) than PB NK cells in response to interleukin-2 (IL-2). Liver NK cells displayed higher cytotoxicity against various breast cancer cell lines (MDA-MB231, MDA-MB453, MDA-MB468, and MCF-7) after IL-2 stimulation than did PB NK cells. Anti-HER2 monoclonal antibody (mAb) promoted the cytotoxicity of both the types of NK cells toward HER2-expressing cell lines. All breast cancer cell lines highly expressed death-inducing TRAIL receptors, death receptor 4, but did not express death-inhibitory receptors (DcR1 and DcR2). Both PB and liver NK cell-induced cytotoxicity was inhibited partially by anti-TRAIL mAb and more profoundly by the combination of anti-TRAIL mAb and concanamycin A, indicating that TRAIL and perforin are involved. IL-2-stimulated liver and PB NK cells exhibited upregulated expression of CXCR3, which bind to the chemokines CXCL9, CXCL10, and CXCL11 secreted by breast cancer cells. We also found that IFN-γ promoted the production of CXCL10 from breast cancer cells. The results of this study show that IFN-γ secreted from NK cells likely promotes the production of CXCL10 from breast cancer cells, which in turn accelerates the migration of CXCR3-expressing NK cells into the tumor site. These findings suggest the possibility of a therapeutic approach by either activation of endogenous PB and liver NK cells or adoptive transfer of in vitro-activated autologous NK cells.     

Two cases of hyperammonemic patients treated by chemotherapy for colorectal cancer

We report two patients having hyperammonemic encephalopathy while being treated with chemotherapy for colorectal cancer. The first patient was a 69-year-old man with sigmoid colon cancer, having a massive invasion to the urinary bladder. He received SOX therapy following a pelvic exenteration operation. After the third course of SOX therapy, he presented with general fatigue and repeated seizures, and blood examination showed a high level of serum ammonium. He was diagnosed as hyperammonemic encephalopathy. The second patients was a 60-year-old woman with ascending colon cancer and liver metastasis having portal vein tumor thrombosis, who was given a palliative resection of ascending colon, and then underwent modified FOLFOX6 therapy. At the second course, she fell into a deep coma, and blood examination revealed a high level of serum ammonium. In both patients, treatment with infusion of branched-chain amino acid solutions resolved the symptoms of encephalopathy. Acute neurotoxicity caused by hyperammonemic encephalopathy during chemotherapy for colorectal cancer is rare and not well recognized, but it is a clinically important complication. We should pay more attention to hyperammonemic encephalopathy of patients receiving chemotherapy for colorectal cancer.     

Prevalence and profile of methamphetamine users in adolescents at a juvenile classification home

The objective of the present study was to investigate the prevalence and risk factors of methamphetamine use in adolescents at a juvenile classification home. The present subjects were 1362 adolescents (1172 male and 190 female) who had been admitted to the Nagoya Juvenile Classification Home. The participants were divided into two groups, a methamphetamine user group and a control group, based on history of methamphetamine use. The presence of methamphetamine use was analyzed in terms of gender, age, number of admissions, violence (types of crime), history of psychiatric treatment, family history (crime, drug misuse and/or alcohol-related disorder), and experience of being abused by their parents or by the persons who were responsible for raising them. The prevalence of methamphetamine use was 6.8% (93/1362). Multivariate logistic regression analyses indicated that gender (female; odds ratio [OR]: 8.1; 95% confidence interval [CI]: 4.6-14.3), age (OR: 1.8, 95%CI: 1.5-2.1), number of admissions (>2, OR: 2.9, 95%CI: 1.8-4.8), violence (OR: 0.4, 95%CI: 0.2-0.7), history of psychiatric treatment (OR: 8.7, 95%CI: 4.0-19.0), and family history of drug misuse (OR: 4.0, 95%CI: 1.6-9.6) were all significantly associated with methamphetamine use. Approximately 7% of participants used methamphetamine. Female gender was a risk factor. Higher age and multiple admissions suggest the persistency and repetition of delinquency. Methamphetamine users were less violent than control subjects. Psychosocial environment (family history of drug misuse) and psychiatric problems (history of psychiatric treatment) were also related to methamphetamine use.