Detection and partial purification of ischaemia-related neurotrophic activity in the periinfarcted brain tissue

In the rat model of middle cerebral artery (MCA) occlusion, axons originating from the ipsilateral cortical and thalamic neurons are injured by ischaemia. The cortical neurons survive thereafter without retrograde degeneration, but thalamic neurons slowly die because of retrograde degeneration. The fate of these two neurons is remarkably different and may be related to neurotrophic activity induced by ischaemia. We detected ischaemia-related neurotrophic activity, and partially purified the factor. Tissue samples were obtained from the cortex adjacent to the infarction and contralateral corresponding site at 4, 8 and 12 days after occlusion of the MCA. They were homogenated with a culture medium and ultracentrifuged. The supernatant was obtained and used for neurotrophic assay. Foetal cortical neurons were obtained from 17 days rat embryo and cultured. Neurotrophic activity was assayed by applying tissue extract to the culture medium. Application of periischaemic cortical extract obtained at 8 and 12 days after ischaemia improved neuronal survival by 50% and 200% as compared to contralateral cortical extract, respectively. The activity was not detectable at 4 days after ischaemia. The neurotrophic activity disappeared by heating the extract at 90 degrees C for 10 min. We fractionated the extract by saturated ammonium sulphate precipitation, followed by gel-filtered with Superose 12 column. The neurotrophic activity was detected in the precipitation of 30 to 60% saturation fraction of ammonium sulphate. With gel-filtration we separated neurotrophic activity in several fractions, which included marker proteins of 8, 22 and 30 kilodaltons. The activities were only detected in the lesioned side but not in the contralateral side.(ABSTRACT TRUNCATED AT 250 WORDS)

Membrane-bound and soluble Fas ligands have opposite functions in photoreceptor cell death following separation from the retinal pigment epithelium

Fas ligand (FasL) triggers apoptosis of Fas-positive cells, and previous reports described FasL-induced cell death of Fas-positive photoreceptors following a retinal detachment. However, as FasL exists in membrane-bound (mFasL) and soluble (sFasL) forms, and is expressed on resident microglia and infiltrating monocyte/macrophages, the current study examined the relative contribution of mFasL and sFasL to photoreceptor cell death after induction of experimental retinal detachment in wild-type, knockout (FasL-/-), and mFasL-only knock-in (ΔCS) mice. Retinal detachment in FasL-/- mice resulted in a significant reduction of photoreceptor cell death. In contrast, ΔCS mice displayed significantly more apoptotic photoreceptor cell death. Photoreceptor loss in ΔCS mice was inhibited by a subretinal injection of recombinant sFasL. Thus, Fas/FasL-triggered cell death accounts for a significant amount of photoreceptor cell loss following the retinal detachment. The function of FasL was dependent upon the form of FasL expressed: mFasL triggered photoreceptor cell death, whereas sFasL protected the retina, indicating that enzyme-mediated cleavage of FasL determines, in part, the extent of vision loss following the retinal detachment. Moreover, it also indicates that treatment with sFasL could significantly reduce photoreceptor cell loss in patients with retinal detachment.

Variations in survival and perioperative complications between hospitals based on data from two phase III clinical trials for oesophageal cancer

BACKGROUND

Variations in institutional practice may contribute to different outcomes of cancer treatment. The impact of interinstitutional heterogeneity on outcomes between hospitals after oesophagectomy has not been examined previously using data from surgical clinical trials.

METHODS

The data from two phase III trials for oesophageal cancer were used. Japan Clinical Oncology Group (JCOG) 9204 involved oesophagectomy (92-OP) versus oesophagectomy plus postoperative chemotherapy (92-POST), with accrual from 1992 to 1997. JCOG9907 involved postoperative chemotherapy (99-POST) versus preoperative chemotherapy (99-PRE), with accrual from 2000 to 2006. Hospitals contributing fewer than three patients were excluded. The influence of time and preoperative chemotherapy on interinstitutional heterogeneity related to postoperative complications and 5-year overall survival were evaluated by comparisons within and between these trial groups. Heterogeneity was estimated by a mixed-effects model after adjusting for age, sex, performance status, location of the primary tumour and clinical stage.

RESULTS

Twelve hospitals in 92-OP (114 patients), 13 in 92-POST (114), 19 in 99-POST (158) and 18 in 99-PRE (154) were eligible. There was considerable heterogeneity in predicted postoperative complications in both groups in JCOG9204 (median 31.3 (range 15.0-68.2) per cent), and in 99-PRE (35.2 (22.6-46.6) per cent) but not in 99-POST (27.7 (27.7-27.7) per cent) from JCOG9907. A similar pattern was seen for predicted overall survival (92-POST: 66.4 (range 64.1-68.9) per cent; 99-PRE: 55.9 (54.0-59.7) per cent; 99-POST: 44.4 (44.4-44.4) per cent).

CONCLUSION

Interinstitutional heterogeneity regarding complications and survival after oesophagectomy is a problem that merits wider consideration.

Macrophage- and RIP3-dependent inflammasome activation exacerbates retinal detachment-induced photoreceptor cell death

Detachment of photoreceptors from the retinal pigment epithelium is seen in various retinal disorders, resulting in photoreceptor death and subsequent vision loss. Cell death results in the release of endogenous molecules that activate molecular platforms containing caspase-1, termed inflammasomes. Inflammasome activation in retinal diseases has been reported in some cases to be protective and in others to be detrimental, causing neuronal cell death. Moreover, the cellular source of inflammasomes in retinal disorders is not clear. Here, we demonstrate that patients with photoreceptor injury by retinal detachment (RD) have increased levels of cleaved IL-1β, an end product of inflammasome activation. In an animal model of RD, photoreceptor cell death led to activation of endogenous inflammasomes, and this activation was diminished by Rip3 deletion. The major source of Il1b expression was found to be infiltrating macrophages in the subretinal space, rather than dying photoreceptors. Inflammasome inhibition attenuated photoreceptor death after RD. Our data implicate the infiltrating macrophages as a source of damaging inflammasomes after photoreceptor detachment in a RIP3-dependent manner and suggest a novel therapeutic target for treatment of retinal diseases.

Does "conversion chemotherapy" really improve survival in metastatic colorectal cancer patients with liver-limited disease?

BACKGROUND

The clinical benefits of conversion chemotherapy followed by liver resection for initially unresectable colorectal liver metastases are still controversial. The criteria for unresectability vary from one team to another. To clarify this issue, we retrospectively assessed the survival and characteristics of metastatic colorectal cancer (mCRC) patients with liver-limited disease (LLD) who underwent conversion therapy.

METHOD

Our criteria for resectability depended on the size of the remnant liver volume (>30 %) and expected function after removal of all metastases. Between December 2007 and September 2011, a total of 115 patients were diagnosed as having mCRC with LLD and received chemotherapy. Among them, 47 had tumors that were initially diagnosed as resectable. They underwent hepatic resection after chemotherapy (resected group). Of the 67 tumors were initially diagnosed as unresectable, 12 became resectable after chemotherapy (conversion group), leaving 55 tumors that remained unresectable after chemotherapy (unresected group).

RESULTS

The median follow-up was 25.2 months. Hepatic resection was more invasive in the conversion group than in the resected group. Median disease-free survival was significantly higher in the resected group than in the conversion group (p = 0.013). Overall survival (OS) was also higher in the resected group, but the difference was not significant (p = 0.36). However, OS was significantly higher in the conversion group than in the unresected group (p = 0.034). Multivariate analysis of the resected and conversion groups showed that OS was significantly negatively influenced by abnormal carcinoembryonic antigen levels at surgery (p = 0.037) and a hospital stay >30 days (p = 0.009).

CONCLUSIONS

Our results showed that conversion chemotherapy could contribute to longer OS in mCRC patients with LLD.

Selective intracellular delivery of proteasome inhibitors through pH-sensitive polymeric micelles directed to efficient antitumor therapy

The ubiquitin-proteasome system is central in the regulation of cellular proteins controlling cell cycle progression and apoptosis, drawing much interest for developing effective targeted cancer therapies. Herein, we developed a novel pH-responsive polymeric-micelle-based carrier system to effectively deliver the proteasome inhibitor MG132 into cancer cells. MG132 is covalently bound to the block copolymer composed of polyethylene glycol (PEG) and polyaspartate through an acid-labile hydrazone bond. This bond is stable at physiological condition, but hydrolytically degradable in acidic compartments in the cell, such as late-endosomes and lysosomes, and thus, it was used for controlled release of MG132 after EPR-mediated preferential accumulation of the micelles into the tumor. MG132-loaded micelles have monodispersed size distribution with an average diameter of 45nm, and critical micelle concentration is well below 10(-7)M. In vitro studies against several cancer cell lines confirmed that MG132-loaded micelles retained the cytotoxic effect, and this activity was indeed due to the inhibition of proteasome by released MG132 from the micelles. Real-time in vitro confocal-microscopy experiments clearly indicated that MG132-conjugated micelles disintegrated only inside the target cells. By intravital confocal micro-videography, we also confirmed the prolonged circulation of MG132 loaded micelles in the bloodstream, which lead to tumor specific accumulation of micelles, as confirmed by in vivo imaging 24h after injection. These micelles showed significantly lower in vivo toxicity than free MG132, while achieving remarkable antitumor effect against a subcutaneous HeLa-luc tumor model. Our findings create a paradigm for future development of polymeric-micelle-based carrier system for other peptide aldehyde type proteasome inhibitors to make them effective cohort of the existing cancer therapeutic regiments.

Mammalian STE20-like kinase 2, not kinase 1, mediates photoreceptor cell death during retinal detachment

Photoreceptor cell death is the definitive cause of vision loss in retinal detachment (RD). Mammalian STE20-like kinase (MST) is a master regulator of both cell death and proliferation and a critical factor in development and tumorigenesis. However, to date the role of MST in neurodegeneration has not been fully explored. Utilizing MST1^−/− and MST2^−/− mice we identified MST2, but not MST1, as a regulator of photoreceptor cell death in a mouse model of RD. MST2^−/− mice demonstrated significantly decreased photoreceptor cell death and outer nuclear layer (ONL) thinning after RD. Additionally, caspase-3 activation was attenuated in MST2^−/− mice compared to control mice after RD. The transcription of p53 upregulated modulator of apoptosis (PUMA) and Fas was also reduced in MST2^−/− mice post-RD. Retinas of MST2^−/− mice displayed suppressed nuclear relocalization of phosphorylated YAP after RD. Consistent with the reduction of photoreceptor cell death, MST2^−/− mice showed decreased levels of proinflammatory cytokines such as monocyte chemoattractant protein 1 and interleukin 6 as well as attenuated inflammatory CD11b cell infiltration during the early phase of RD. These results identify MST2, not MST1, as a critical regulator of caspase-mediated photoreceptor cell death in the detached retina and indicate its potential as a future neuroprotection target.

Relationship between xerostomia and gingival condition in young adults

BACKGROUND AND OBJECTIVE

Xerostomia is a subjective symptom of dryness in the mouth. Although a correlation between xerostomia and oral conditions in the elderly has been reported, there are few such studies in the young adults. The aim of this study was to examine the relationship of xerostomia with the gingival condition in university students.

MATERIAL AND METHODS

A total of 2077 students (1202 male subjects and 875 female subjects), 18-24 years of age, were examined. The disease activity and severity of the gingival condition were assessed as the percentage of teeth with bleeding on probing (%BOP) and the presence of teeth with probing pocket depth of ≥ 4 mm, respectively. Additional information on xerostomia, oral health behaviors, coffee/tea intake and nasal congestion was collected via a questionnaire. Path analysis was used to test pathways from xerostomia to the gingival condition.

RESULTS

One-hundred and eighty-three (8.8%) students responded that their mouths frequently or always felt dry. Xerostomia was related to %BOP and dental plaque formation, but was not related to the presence of probing pocket depth ≥ 4 mm. In the structural model, xerostomia was related to dental plaque formation (p < 0.01), and a lower level of dental plaque formation was associated with a lower %BOP. Xerostomia was associated with coffee/tea intake (p < 0.01) and nasal congestion (p < 0.001).

CONCLUSION

Xerostomia was indirectly related to gingival disease activity through the accumulation of dental plaque. Nasal congestion and coffee/tea intake also affected xerostomia. These findings suggest that xerostomia should be considered in screening for gingivitis risk in young adults.

Programmed necrosis, not apoptosis, is a key mediator of cell loss and DAMP-mediated inflammation in dsRNA-induced retinal degeneration

There is no known treatment for the dry form of an age-related macular degeneration (AMD). Cell death and inflammation are important biological processes thought to have central role in AMD. Here we show that receptor-interacting protein (RIP) kinase mediates necrosis and enhances inflammation in a mouse model of retinal degeneration induced by dsRNA, a component of drusen in AMD. In contrast to photoreceptor-induced apoptosis, subretinal injection of the dsRNA analog poly(I : C) caused necrosis of the retinal pigment epithelium (RPE), as well as macrophage infiltration into the outer retinas. In Rip3(-/-) mice, both necrosis and inflammation were prevented, providing substantial protection against poly(I : C)-induced retinal degeneration. Moreover, after poly(I : C) injection, Rip3(-/-) mice displayed decreased levels of pro-inflammatory cytokines (such as TNF-α and IL-6) in the retina, and attenuated intravitreal release of high-mobility group box-1 (HMGB1), a major damage-associated molecular pattern (DAMP). In vitro, poly(I : C)-induced necrosis were inhibited in Rip3-deficient RPE cells, which in turn suppressed HMGB1 release and dampened TNF-α and IL-6 induction evoked by necrotic supernatants. On the other hand, Rip3 deficiency did not modulate directly TNF-α and IL-6 production after poly(I : C) stimulation in RPE cells or macrophages. Therefore, programmed necrosis is crucial in dsRNA-induced retinal degeneration and may promote inflammation by regulating the release of intracellular DAMPs, suggesting novel therapeutic targets for diseases such as AMD.

Experimental Study on Dewatering and Devolatilizing Operations Using Intermeshed Twin Screw Extruders

In this study, we have mainly discussed the dewatering and devolatilizing extrusion behavior of synthetic elastomers using intermeshed twin screw extruders. For these purposes, we utilized various twin screw extruders with long segmented barrels having several slitted sections and venting ports. Furthermore, we selected the optimum operational conditions using either the intermeshed co- or counter-rotation twin screw extruder depending on experimental purposes and raw materials. Some results obtained were compared between the co- and counter-rotation twin screw extruder.

Health-related quality of life does not predict mortality in idiopathic pulmonary fibrosis

BACKGROUND

Although health-related quality of life (HRQL) has recently been considered to be an important outcome in clinical trials of idiopathic pulmonary fibrosis (IPF), its relationship with survival is unknown.

OBJECTIVE

To determine the prognostic significance of HRQL scores in IPF assessed with the SGRQ.

DESIGN

Eighty-seven consecutive patients with IPF, who had undergone evaluations and completed the St. George's Respiratory Questionnaire (SGRQ) at diagnosis were included in this study, as is the general practice. Cox proportional hazards analyses were performed to examine the relationship between HRQL scores and survival.

RESULTS

The mean observation period was 44.2 +/- 29.6 mo, in the course of which 54 patients (62.0%) died. Univariate analysis revealed that the activity scores in the SGRQ(HR: 1.016, 95% CI: 1.004-1.029, P = 0.01) were significantly predictive of survival, although the symptoms, impacts, and total scores were not significantly related to mortality from all causes. However, multivariate analysis revealed that only the forced vital capacity percent predicted was a significant predictor of survival, and that the activity score in the SGRQwas not significantly related to mortality.

CONCLUSIONS

There was no significant relationship between HRQL evaluated with the SGRQ and the subsequent mortality in IPF. The present negative result might suggest that HRQL is measuring an aspect other than one from physiological and functional impairment or disability.

Evaluation of innate immune stimulating activity of polysaccharides using a silkworm (Bombyx mori) muscle contraction assay

In silkworm larvae, the mature form of paralytic peptide (PP), an insect cytokine, is produced from pro-PP in association with activation of innate immune responses, resulting in slow muscle contraction. We utilized this reaction, muscle contraction in silkworms coupled with innate immunity stimulation, to quantitatively measure the innate immune stimulating activity of various natural polysaccharides. β-Glucan of Gyrophora esculenta (GE-3), fucoidan from sporophyll of Undaria pinnatifida, and curldan induced silkworm muscle contraction. We further demonstrated that GE-3 had therapeutic effects on silkworms infected by baculovirus. Based on these findings, we propose that the silkworm muscle contraction assay is useful for screening substances that stimulate innate immunity before evaluating therapeutic effectiveness in mammals.

Polymeric micelles incorporating (1,2-diaminocyclohexane)platinum (II) suppress the growth of orthotopic scirrhous gastric tumors and their lymph node metastasis

Nano-scaled drug carriers have great potential for the treatment of solid tumors. Nevertheless, hypovascularity and fibrosis in some types of solid tumors have been demonstrated to reduce the penetration and accumulation of nano-scaled drug carriers. Diffuse-type scirrhous gastric cancers present such characteristics as well as frequent metastasis to the lymph nodes; therefore, it remains a great challenge to eradicate scirrhous gastric cancers based on the drug targeting using nanocarriers. Herein, we demonstrated that polymeric micelles with 30-nm diameter incorporating (1,2-diaminocyclohexane)platinum(II) (DACHPt), the parent complex of the anticancer drug oxaliplatin, efficiently penetrated and accumulated in an orthotopic scirrhous gastric cancer model, leading to the inhibition of the tumor growth. Moreover, the elevated localization of systemically injected DACHPt-loaded micelles in metastastic lymph nodes reduced the metastatic tumor growth. These results suggest DACHPt-loaded micelles as a promising nanocarrier for the treatment of scirrhous gastric cancers and their lymphatic metastases.