Application of Ultrasound for Targeted Nanotherapy of Malignant Tumors

The article describes the study of targeted chemotherapeutic intervention on solid tumors by means of ultrasound and doxorubicin- or paclitaxel-loaded perfluoropentane nanoemulsions. Nanodroplets of the emulsions accumulated in a tumor by passive targeting. Under the action of a tumor-directed therapeutic ultrasound, the nanodroplets converted into vapor microbubbles. In vivo, the nanodroplets strongly retained the loaded drugs; yet, under ultrasound-mediated vaporization they released the drugs into the tumor tissue, thereby implementing effective targeting into the tumor. The tumors subjected to this treatment regressed effectively; however, after some time they recurred. The recurring tumors were more resistant to the repeated therapy than the primary ones. At present, the causes of of the resistance development and methods for its elimination are unclear and they are under investigation.

A micro creeping robot for colonoscopy based on the earthworm

Minimally Invasive Surgery (MIS) has become one of the most important research areas in the field of medical engineering. Robotic colonoscopy is a typical medical procedure that complies with the requirements of MIS. In this paper, a new novel miniature robot for intestinal inspection based on the earthworm is described; its diameter and length are 7.5 mm and 120 mm respectively. The micro robot is driven by a DC motor which has good performance and sufficient power. In this paper the structure and locomotion mechanism of this robot are introduced; the mechanical model is built; and simulation is carried out. The control system and software design are also discussed in detail. Some actuating characteristic experiments have been performed, where the micro robot creeps in declining rubber tubes. The experimental results are in accord with simulation results, and show that this kind of robot can move reliably in horizontal and certain declining tubes. This research has laid a foundation for the application of the miniature robot endoscope.

Treatment guided by ERCC1, RRM1, and BRCA1 protein expression in patients with advanced-stage NSCLC

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Purpose: We investigated whether Treatment Guided by ERCC1,RRM1 and BRCA1 protein expression levels could improve clinical outcomes in Patients With Advanced-Stage NSCLC. Experimental Design: Eligibility: Main inclusion criteria: Stage IV or stage IIIB NSCLC; Eastern Cooperative Oncology Group(ECOG) performance status (PS) 0–1; Measurable disease; Adequate bone marrow, kidney, liver function. Main exclusion criteria: previous NSCLC therapy; Central nervous system metastasis; Requiring immediate intervention or Untreated with radiation within 28 days of study regimen initiation. Previously untreated patients with Stage IV or stage IIIB NSCLC(N=180): Standard chemotherapy group(N=60): Cisplatin 75mg/m2 Day1+Vinorelbine 25mg/m2 Days 1,8 every 28 days; Individualized chemotherapy group (N=120) (ERCC1,RRM1 and BRCA1 protein expression assayed with IHC); Low ERCC1 protein expression subgroup: Cisplatin 75mg/m2 Day1+Vinorelbine 25mg/m2 Days 1,8 every 28 days; High ERCC1 protein subgroup: Vinorelbine 25mg/m2 Days 1,8+Gemcitabine 1250mg/m2 Days 1,8 every 28 days. Description of Current Analysis: ERCC1,RRM1 and BRCA1 protein expression assayed with IHC; Assigned treatment based on ERCC1 protein expression; Primary endpoint: overall response rate; Secondary endpoints: Overall survival (OS), Progression-free survival (PFS). Enrollment progress (As of time Dec-31–2008): See Table .

[Table: see text]

No significant financial relationships to disclose.

Effect of zoledronic acid combined with cisplatin and paclitaxel on inhibition of non-small cell lung cancer cell lines

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Backgrounds: Recent studies reported that zoledronic acid, a biphosphonate with proposed apoptotic activity, could cause a direct antitumor effect. Our prior study [J Clin Oncol 26: 2008 (May 20 suppl; abstr 19116)] reported that Zoledronic acid combined with Cisplatin shows significantly synergistic antitumor effects on lung cancer cell line A549 and subcutaneous implanted tumor on nude mice. Investigate whether zoledronic acid, augmented the cytotoxicity of cisplatin and/or paclitaxel in A549 lung cancer cell line. Methods: This cell line was subjected to different concentrations of the above chemotherapeutic agents and zoledronic acid. Cytotoxicity was assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide) assay. Flow cytometry was used to examine cell cycle,cell apoptosis rate. Results: Zoledronic acid in in 50 micromolar (mM) concentration augmented the cytotoxicity by cisplatin in 10μmol/L and paclitaxel in 5μmol/L. Zoledronic acid could inhibit the proliferation of lung cancer cells in vitro,which was associated with arresting of G1 phase and inducing apoptosis by a time-dependent and dose-dependentmanner. The apoptosis rate of cell increased after zoledronic acid combined with cisplatin and/or paclitaxel. Conclusions: Zoledronic acid can induce apoptosis and block cell cycle of lung cancer cells. Zoledronic acid has also shown synergistic antitumor effects when combined with cisplatin and/or paclitaxel. The clinical potential of this finding should be further studied.

No significant financial relationships to disclose.

Microglial activation and intracerebral hemorrhage

INTRODUCTION

Microglia activate upon injury, migrate to the injury site, proliferate locally, undergo morphological and gene expression changes, and phagocytose injured and dying cells. Cytokines and proteases secreted by these cells contribute to the injury and edema formed. We studied the injury outcome after local elimination/paralysis of microglia.

METHODS

Adult male mice were subjected to intracerebral hemorrhage (ICH) by intra-caudate injection of either collagenase or autologous blood. Mice survived for different periods of time, and were subsequently evaluated for neurological deficits, size of the hematoma, and microglia activation. Mice expressing an fms-GFP transgene or the CD11b-HSVTK transgene were also used. For elimination of monocytes/macrophages, CD11b-HSVTK mice were treated with ganciclovir prior to hemorrhage. Modifiers of microglial activation were also used.

RESULTS

Induction of ICH resulted in robust microglia activation and recruitment of macrophages. Inactivation of these cells, genetically or pharmacologically, pointed to a critical role of the time of such inactivation, indicating that their role is distinct at different time points following injury. Edema formation is decreased when microglia activation is inhibited, and neurological outcomes are improved.

CONCLUSIONS

Microglia, as immunomodulatory cells, have the ability to modify the final presentation of ICH.

67-kDa laminin receptor in human bile duct carcinoma

BACKGROUND/AIM

Abnormal interaction of epithelial cells with laminin component of basement membrane may account for altered biological behavior of cells, influencing proliferation, adhesion, and motility. In the current study, we investigated the role of 67-kDa laminin receptor (67LR), a high affinity receptor for laminin, in aggressiveness of bile duct carcinoma.

METHODS

Fifty-two paraffin-embedded specimens and 22 fresh tissues of patients with bile duct carcinoma were analyzed using immunohistologic and real-time polymerase chain reaction techniques, respectively. Expression of 67LR on the bile duct carcinoma QBC939 cells was examined by flow cytometry. The effects of 67LR on the adhesive and invasive abilities of QBC939 cells were determined by adhesion and invasion assay in vitro.

RESULTS

Both at the mRNA and protein level, bile duct carcinoma cells expressed a higher level of 67LR than normal epithelial cells (p < 0.01). The expression of 67LR was correlated inversely with differentiation extent of tumor (p < 0.05). The 67LR level was significantly increased in patients with lymph node metastases than in patients without lymph node involvement (p < 0.01). Flow cytometry showed that 69.9 +/- 1.1% of QBC939 cells expressed 67LR. Expression of 67LR increased the adhesion and invasion of QBC939 cells. 60 and 120 min of incubation of 67LR antibodies, MLuC5, induced 46.3 +/- 2.2 and 61.3 +/- 2.1% inhibition of adhesion, respectively. The invasive ability of QBC939 cells to Matrigel was also reduced by 67LR antibodies, MLuC5.

CONCLUSIONS

Overexpressing 67LR on bile duct carcinoma was associated with invasion and metastasis of bile duct carcinoma. Blockage of 67LR suppressed adhesion and invasion of bile duct carcinoma.

Clinical study and PLA2G6 mutation screening analysis in Chinese patients with infantile neuroaxonal dystrophy

BACKGROUND AND PURPOSE

Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder. The most typical neuropathological finding of this disease is axonal swelling. Before the identification of associated mutations in PLA2G6-encoding iPLA(2)-VIA (cytosolic Ca(2+)-independent phospholipids A(2), group VIA) in 2006, neuropathological evidence was critical for definitive diagnosis. Only five genetic studies in INAD patients have been published worldwide, wherein 44 mutations were reported. To define the clinical and genetic characteristics of Chinese patients with INAD, 10 cases were analyzed.

METHODS

For 10 cases of INAD, extensive clinical investigations, neuropathological examination, and mutation screening in PLA2G6 were performed.

RESULTS

All cases displayed typical clinical features. Axonal swelling was found in skin or sural nerve biopsy specimens in three cases. Twelve PLA2G6 mutations were identified, nine of which were novel. These novel mutations include six missense, one abolishing the normal start codon, one nonsense, and one splice-site mutation.

CONCLUSIONS

The nine novel mutations identified in this study suggest the uniqueness of the PLA2G6 mutation spectrum in Chinese patients, and greatly extends the spectrum of known mutations in INAD patients. In addition to pathological evidence, genetic analysis can inform definitive diagnosis of INAD.

Distinctly different expression of cytokines and chemokines in the lungs of two H5N1 avian influenza patients

The pathogenesis of human H5N1 influenza remains poorly understood and controversial. 'Cytokine storm' has been hypothesized to be the main cause of the severity of this disease. However, the significance of this hypothesis has been called into question by a recent report, which demonstrates that inhibition of the cytokine response did not protect against lethal H5N1 influenza infection in mice. Here we showed discrepant findings in two adult H5N1 autopsies and a fetus obtained at autopsy which also raise doubt about this hypothesis. Antigens of 10 cytokines/chemokines which were found to be significantly elevated in previous H5N1-infected patients and in vitro experiments, and mRNA of eight of these, were absent from the lungs of a pregnant woman and her fetus. In contrast, antigens of seven cytokines/chemokines and mRNA of six of these were found to be increased in the lungs of a male autopsy. The cells expressing these cytokines and chemokines were identified as type II pneumocytes, bronchial epithelial cells, macrophages and vascular endothelial cells. Levels of cytokines and chemokines in the serum of the male case were also significantly higher than those of infectious (infection other than by H5N1) and non-infectious controls. In comparison with results from our previous study, it appeared that the male case had increased cytokine/chemokine expression but reduced viral load, while the pregnant female had diminished cytokine/chemokine expression but a significantly increased viral load in the lungs. These disparate findings in these two cases suggest that 'cytokine storm' alone could not be a sufficient explanation for the severe lung injury of this newly emerging disease.

Methane and ammonia emissions from a beef feedlot in western Canada for a twelve-day period in the fall

Commercial feedlot operations are becoming a mainstay in the Canadian beef industry. These large operations that typically raise thousands of animals at a time represent a large localized source of methane (CH4) and of atmospheric pollutants such as ammonia (NH3) and particulate matter. An inverse dispersion model was utilized to calculate CH4 and NH3 emissions from a commercial cattle feedlot and an adjacent runoff retention pond. The feedlot measurements were collected within the interior of the feedlot enabling a near continuous emissions record over the 12 d of the study period. Average daily emission estimates of CH4 and NH3 were 323 and 318 g animal-1 d-1, respectively. The CH4 emissions represent 4% of the gross energy intake (GEI) and NH3 emissions represent 72% of the total N intake. Emissions from the runoff retention pond associated directly with the feedlot operation were approximately 2.7 and 2% of the daily average feedlot emissions of CH4 and NH3, respectively. Key words: Methane, ammonia, inverse dispersion, ruminant livestock, trace gas emissions

Taxonomy of the Streptomyces strain ZG0656 that produces acarviostatin alpha-amylase inhibitors and analysis of their effects on blood glucose levels in mammalian systems

AIMS

To clarify the taxonomic status of strain ZG0656 and analyse the effects of its acarviostatin products on blood glucose levels in mammalian systems.

METHODS AND RESULTS

Our program to screen for new alpha-amylase inhibitors led to the isolation of strain ZG0656. The polyphasic taxonomic study revealed that strain ZG0656 represents a novel variation of Streptomyces coelicoflavus, for which we propose the name S. coelicoflavus var. nankaiensis. Four chemically distinct alpha-amylase inhibitors, acarviostatins I03, II03, III03 and IV03, were isolated from strain ZG0656. Acarviostatins III03 and IV03 are both novel oligomers. All four acarviostatins are mixed noncompetitive porcine pancreas alpha-amylase inhibitors. Acarviostatin III03 is the most potent alpha-amylase inhibitor known to date. Moreover, in the in vitro and in vivo experiments, acarviostatins III03 showed significant inhibition of starch hydrolysis and glucose transfer to blood.

CONCLUSIONS

Strain ZG0656 is a novel variation of S. coelicoflavus, whose products are novel effective alpha-amylase inhibitors. Among the products, acarviostatins III03 could significantly depress blood glucose levels in mammalian systems and be developed towards a possible therapeutic agent for diabetes.

SIGNIFICANCE AND IMPACT OF THE STUDY

Acarviostatin III03 is the most potent alpha-amylase inhibitor known to date. The oligomer will benefit the research on the relationship between alpha-amylase and various inhibitors and will offer more choices in diabetes treatments.

Differences in attitudes, beliefs and knowledge of hospital health care workers and community doctors to vaccination of older people

Pneumococcal disease and influenza are major causes of morbidity and mortality particularly among the elderly. Influenza and pneumococcal vaccination are recommended for people aged 65 years and older or persons with chronic illness. However, despite the burden of disease related to pneumococcus and influenza and the availability safe, efficacious and cost-effective vaccines, health care providers continue to have doubts about these vaccines. Little is known about barriers for pneumococcal vaccination in the health care providers particularly in the primary health care setting. Since 2005 a publicly funded program offering free pneumococcal vaccine for elderly people over 65 years has been implemented in Australia.

AIM

To investigate knowledge, attitudes and practices around vaccination of elderly patients among hospital health care workers and community general practitioners and to explore the difference between hospital doctors and GP.

METHODS

A self-reported questionnaire survey distrubuted March and June 2007 to General physicians (GP's) whose practices are located in Western Sydney and health care staff consisting of Hospital Doctors (HD), hospital nurses (HN) and allied health care workers at a tertiary referral hospital in Western Sydney. Descriptive analyses were conducted; bivariate analyses were performed to investigate associations between variables.

RESULTS

Completed surveys were obtained for 56.3% (335/595) GPs and 42.1% (346/822) for HHCWs. The HHCWs comprised 37.5% (130/346) HD, 57.8% (200/346) HN and 4.6% (16/346) allied health care workers. GP's are more likely to support elderly vaccination than hospital doctors (98.8% compared to 93%, P=0.0007). GPs reported that the reason for not vaccinating patients in 88% (295/335) of the cases was due to patient refusal. GP's and HHCW both agreed that pneumococcal disease is a serious illness and that vaccination is an important preventive measure for the elderly. However, the majority 68.2% (88/129) of hospital doctors report that vaccinations are difficult to address due to multiple competing priorities compared to only 34.6% (116/335) of GPs, P<0.0001. Hospital doctors are more likely than GPS (24% vs. 17%) to report that patients often complain of adverse effects from pneumococcal vaccine. Hospital doctors 20% (104/130) are significantly less likely than GPs<1% (3/335) to have access to guidelines and other information regarding vaccination in the elderly.

CONCLUSIONS

GPs and hospital health care workers in our study were aware of, agreed with, immunization recommendation for the pneumococcal vaccine. Physician barriers to vaccination were patient's refusals and competing priorities, particularly for hospital health care workers, who were less likely to see vaccination as a priority. Hospitalisation is an opportunity for vaccination, but utilisation of this opportunity is reduced by lack of access to information about immunization for hospital health care workers and competing priorities. These could be areas to target for improved uptake of the elderly immunization.

TEMPEST simulations of collisionless damping of the geodesic-acoustic mode in edge-plasma pedestals

The fully nonlinear (full-f) four-dimensional TEMPEST gyrokinetic continuum code correctly produces the frequency and collisionless damping of geodesic-acoustic modes (GAMs) and zonal flow, with fully nonlinear Boltzmann electrons for the inverse aspect ratio scan and the tokamak safety factor q scan in homogeneous plasmas. TEMPEST simulations show that the GAMs exist in the edge pedestal for steep density and temperature gradients in the form of outgoing waves. The enhanced GAM damping may explain experimental beam emission spectroscopy measurements on the edge q scaling of the GAM amplitude.