Efficacy of Kanglaite against radiotherapy-induced mucositis in head and neck cancer, a phase II trial

PURPOSE

To explore the potential protective effect of Kanglaite injection against radiotherapy-induced mucositis in patients with head and neck cancer.

PATIENTS AND METHODS

This was an open-label, single-arm, and phase II trial. The primary endpoint was the incidence of grade 3-4 radiation-induced mucositis. The secondary endpoints were hematological toxicity, non-hematological toxicity, nutritional status, and quality of life. All patients received 20g Kanglaite daily concurrently with radiotherapy.

RESULTS

The data of 46 patients were available for analysis. The incidence rates of grade 3 mucositis, pain, dysphagia, and neutropenia were 10.9%, 2.2%, 10.9%, and 6.5%, respectively, while the incidence of grade 4 acute toxicities was zero. The rate of opioid use was 2.2%. Radiotherapy dose reduction was 2.2% and no irradiation field was modified. The nutritional supports were oro-enteral nutritional supplements (13.0%), TPN (10.9%), and feeding tubes (0%) during radiotherapy. After radiotherapy, 52.2% of patients lost weight, and the weight loss was <10%. The mean pain score in the QLQ-H&N35 and QLQ-C30 was <50. Patients had nearly normal physical, emotional, and cognitive functions.

CONCLUSIONS

A low incidence of grade 3-4 radiation-induced mucositis and no severe acute toxic events, with favorable nutritional status and quality of life, were observed in cancer patients after Kanglaite injection. Our findings highlight the need for a prospective, multicenter, and randomized study to investigate the effect of Kanglaite injection on the reduction of radiation-induced mucositis in patients with head and neck cancer.

Paxillin confers resistance to tyrosine kinase inhibitors in EGFR-mutant lung cancers via modulating BIM and Mcl-1 protein stability

Tyrosine kinase inhibitors (TKIs) have been documented to have substantial clinical benefits to non-small cell lung cancer with epidermal growth factor receptor (EGFR) mutation. TKI resistance occurs in nearly all patients who receive TKI-targeting therapy, resulting in a modest overall survival benefit. Therefore, establishing a biomarker for early prediction and exploring the mechanism of primary TKI resistance is essential for improving the therapeutic efficacy in non-small cell lung cancer patients. In this study, we provide evidence indicating that paxillin (PXN) overexpression may confer TKI resistance in EGFR-mutant lung cancer cells. Mechanistically, PXN-mediated extracellular signal-regulated kinases (ERK) activation is responsible for TKI resistance via decreased Bcl2-interacting mediator of cell death (BIM) and increased Mcl-1 expression due to modulating their protein stabilities by phosphorylation of BIM at serine 69 and Mcl-1 at threonine 163. The mechanistic action in the cell model was further confirmed by the observation of xenograft tumors in nude mice, revealing that the PXN-mediated TKI resistance was conquered by ERK inhibitor (AZD6244) and Bcl-2 family inhibitor (obatoclax), but the TKI resistance overcome by AZD6244 is more effective than that of obatoclax. Therefore, we suggest that PXN expression may be useful in predicting primary TKI resistance, and combining TKI with ERK inhibitors may clinically benefit EGFR-mutant non-small cell lung cancer patients whose tumors exhibit high PXN expression.

Biodegradable poly-lactic acid based-composite reinforced unidirectionally with high-strength magnesium alloy wires

Biodegradable poly-lactic acid (PLA)--based composites reinforced unidirectionally with high-strength magnesium alloy wires (MAWs) are fabricated by a heat-compressing process and the mechanical properties and degradation behavior are studied experimentally and theoretically. The composites possess improved strengthening and toughening properties. The bending strength and impact strength of the composites with 40 vol% MAWs are 190 MPa and 150 kJ/m(2), respectively, although PLA has a low viscosity and an average molecular weight of 60,000 g/mol. The mechanical properties of the composites can be further improved by internal structure modification and interface strengthening and a numerical model incorporating the equivalent section method (ESM) is proposed for the bending strength. Micro arc oxidization (MAO) of the MAWs is an effective interfacial strengthening method. The composites exhibit high strength retention during degradation and the PLA in the composite shows a smaller degradation rate than pure PLA. The novel biodegradable composites have large potential in bone fracture fixation under load-bearing conditions.

Efficacy of gradual pressure-decline compressing stockings in Asian patients with lower leg varicose veins: analysis by general measurements and magnetic resonance image

AIM

Most applications of gradual pressure-decline compressing stockings (GPDCS) are used in the United States and Western European countries, with over a decade of clinical experiments. Up to know, there is no standard establishment of gradual pressure-decline compressing stockings for Asian patients with venous insufficiency and varicose vein formations.

METHODS

We collected data on volunteer candidates of varicose vein for general measurements and assessments and magnetic resonance imaging (MRI) by non-contrast enhanced MRV techniques, and for post processing data analysis.

RESULTS

Clinical use of GPCDS provide a mild to moderate improvement in the varicose vein conditions of patients with deep venous insufficiency by improving their deep vein circulation, by general measurements; recording major symptoms and complaint; comfort and stretching/flexibility to the candidates after using GPDCS; and area changes/flow velocity changes/available hemoglobin changes in deep veins monitored by MRI.

CONCLUSION

The benefits and data collected in these results may help in developing compression stockings standards in Taiwanese and Asian countries, and to establishing criterias for product sizes, compression levels, and related parameters.

Surface hardening of NiTi shape memory alloy induced by the nanostructured layer after surface mechanical attrition treatment

To conduct grain refinement induced by plastic deformation, NiTi shape memory alloy is processed by surface mechanical attrition treatment. The process leads to surface nanocrystallization and consequently surface hardening. The cross sectional microhardness of the treated NiTi is measured and compared to those of annealed NiTi specimens with residual stress relaxation and recrystallization. Our results show that surface nanocrystallization induced by surface mechanical attrition treatment is an effective method to enhance the surface hardness and anti-wear properties of NiTi shape memory alloy for the biomedical application.

Surface nanomechanical behavior of ZrN and ZrCN films deposited on NiTi shape memory alloy by magnetron sputtering

Surface nanomechanical behavior under nanoindentation of ZrN and ZrCN film on NiTi substrate was studied. The surface hardness and modulus of the films increase initially with larger nanoindentation depths and then reach their maximum values. Afterwards, they diminish gradually and finally reaching plateau values which are the composite modulus and composite hardness derived from the ZrN/ZrCN film and NiTi substrate. They are higher than those of electropolished NiTi SMA due to the properties of ZrN and ZrCN. In comparison, the surface nanomechanical properties of electropolished NiTi exhibit a different change with depths.

Impact of model uncertainty on soil quality standards for cadmium in rice paddy fields

At present, soil quality standards used for agriculture do not consider the influence of pH and CEC on the uptake of pollutants by crops. A database with 750 selected paired samples of cadmium (Cd) in soil and paddy rice was used to calibrate soil to plant transfer models using the soil metal content, pH, and CEC or soil Cd and Zn extracted by 0.01 M CaCl₂ as explanatory variables. The models were validated against a set of 2300 data points not used in the calibration. These models were then used inversely to derive soil quality standards for Japonica and Indica rice cultivars based on the food quality standards for rice. To account for model uncertainty, strict soil quality standards were derived considering a maximum probability that rice exceeds the food quality standard equal to 10 or 5%. Model derived soil standards based on Aqua Regia ranged from less than 0.3 mg kg⁻¹ for Indica at pH 4.5 to more than 6 mg kg⁻¹ for Japonica-type cultivars in clay soils at pH 7. Based on the CaCl₂ extract, standards ranged from 0.03 mg kg⁻¹ Cd for Indica cultivars to 0.1 mg kg⁻¹ Cd for Japonica cultivars. For both Japonica and Indica-type cultivars, the soil quality standards must be reduced by a factor of 2 to 3 to obtain the strict standards. The strong impact of pH and CEC on soil quality standards implies that it is essential to correct for soil type when deriving national or local standards. Validation on the remaining 2300 samples indicated that both types of models were able to accurately predict (> 92%) whether rice grown on a specific soil will meet the food quality standard used in Taiwan.

Prediction of Cadmium uptake by brown rice and derivation of soil-plant transfer models to improve soil protection guidelines

Cadmium (Cd) levels in paddy fields across Taiwan have increased due to emission from industry. To ensure the production of rice that meets food quality standards, predictive models or suitable soil tests are needed to evaluate the quality of soils to be used for rice cropping. Levels of Cd in soil and rice grains were measured in 19 paddy fields across the western plains in Taiwan. Cadmium levels in soil range from less than 0.1 mg kg(-1) to 30 mg kg(-1). Measured Cd levels in brown rice were predicted very well (R(2) > 0.8) based on Cd and Zinc in a 0.01 M CaCl(2) extract or a soil-plant transfer model using the reactive soil Cd content, pH, and cation exchange capacity. In contrast to current soil quality standards used in Taiwan, such models are effective in identifying soils where Cd in rice will exceed food quality standards.

Nano-scale surface morphology, wettability and osteoblast adhesion on nitrogen plasma-implanted NiTi shape memory alloy

Plasma immersion ion implantation (PIII) is an effective method to increase the corrosion resistance and inhibit nickel release from orthopedic NiTi shape memory alloy. Nitrogen was plasma-implanted into NiTi using different pulsing frequencies to investigate the effects on the nano-scale surface morphology, structure, wettability, as well as biocompatibility. X-ray photoelectron spectroscopy (XPS) results show that the implantation depth of nitrogen increases with higher pulsing frequencies. Atomic force microscopy (AFM) discloses that the nano-scale surface roughness increases and surface features are changed from islands to spiky cones with higher pulsing frequencies. This variation in the nano surface structures leads to different surface free energy (SFE) monitored by contact angle measurements. The adhesion, spreading, and proliferation of osteoblasts on the implanted NiTi surface are assessed by cell culture tests. Our results indicate that the nano-scale surface morphology that is altered by the implantation frequencies impacts the surface free energy and wettability of the NiTi surfaces, and in turn affects the osteoblast adhesion behavior.

XPS and biocompatibility studies of titania film on anodized NiTi shape memory alloy

A dense titania film is fabricated in situ on NiTi shape memory alloy (SMA) by anodic oxidation in a Na(2)SO(4) electrolyte. The microstructure of the titania film and its influence on the biocompatibility of NiTi SMA are investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICPMS), hemolysis analysis, and platelet adhesion test. The results indicate that the titania film has a Ni-free zone near the surface and can effectively block the release of harmful Ni ions from the NiTi substrate in simulated body fluids. Moreover, the wettability, hemolysis resistance, and thromboresistance of the NiTi sample are improved by this anodic oxidation method.

A biomimetic hierarchical scaffold: natural growth of nanotitanates on three-dimensional microporous Ti-based metals

Nanophase materials are promising alternative implant materials in tissue engineering. Here we report for the first time the large-scale direct growth of nanostructured bioactive titanates on three-dimensional (3D) microporous Ti-based metal (NiTi and Ti) scaffolds via a facile low temperature hydrothermal treatment. The nanostructured titanates show characteristics of 1D nanobelts/nanowires on a nanoskeleton layer. Besides resembling cancelous bone structure on the micro/macroscale, the 1D nanostructured titanate on the exposed surface is similar to the lowest level of hierarchical organization of collagen and hydroxyapatite. The resulting surface displays superhydrophilicity and favors deposition of hydroxyapatite and accelerates cell attachment and proliferation. The remarkable simplicity of this process makes it widely accessible as an enabling technique for applications from engineering materials treatment including energy-absorption materials and pollution-treatment materials to biotechnology.

Surface structure and properties of biomedical NiTi shape memory alloy after Fenton's oxidation

Fenton's oxidation is traditionally used to remove inorganic and organic pollutants from water in waster water treatment. It is an advanced oxidation process in which H2O2 is catalytically decomposed by ferrous irons into hydroxyl radicals (*OH) which have a higher oxidation potential (2.8V) than H2O2. In the work reported here, we for the first time use Fenton's oxidation to modify the surface of biomedical NiTi shape memory alloy (SMA). The influences of Fenton's oxidation on the surface microstructure, blood compatibility, leaching of harmful Ni ions and corrosion resistance in simulated body fluids is assessed using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, inductively coupled plasma mass spectrometry, electrochemical tests, hemolysis analysis and the blood platelet adhesion test. The mechanical stability of the surface titania film produced by Fenton's oxidation as well as their effects on the shape memory behavior of the SMA are studied by bending tests. Our results show that Fenton's oxidation produces a novel nanostructured titania gel film with a graded structure on the NiTi substrate without an intermediate Ni-rich layer that is typical of high-temperature oxidation. Moreover, there is a clear Ni-free zone near the top surface of the titania film. The surface structural changes introduced by Fenton's oxidation improve the electrochemical corrosion resistance and mitigate Ni release. The latter effects are comparable to those observed after oxygen plasma immersion ion implantation reported previously and better than those of high-temperature oxidation. Aging in boiling water improves the crystallinity of the titania film and further reduces Ni leaching. Blood platelet adhesion is remarkably reduced after Fenton's oxidation, suggesting that the treated SMA has improved thrombo resistance. Enhancement of blood compatibility is believed to stem from the improved hemolysis resistance, the surface wettability and the intrinsic electrical characteristics of the titania film. The titania film produced by Fenton's oxidation has good mechanical stability and does not adversely impact the shape memory behavior of NiTi. Our work suggests that Fenton's oxidation is a promising low-temperature, low-cost surface modification method for improving the surface properties of biomedical NiTi SMA.

Nickel release behavior, cytocompatibility, and superelasticity of oxidized porous single-phase NiTi

Porous NiTi shape memory alloys are one of the promising biomaterials for surgical implants because of their unique shape memory effects and porous structure with open pores. However, the complex surface morphology and larger area of porous NiTi compared to dense NiTi make it more vulnerable from the viewpoint of release of nickel, which can cause deleterious effects in the human body. It is also more difficult to modify the exposed surfaces of a porous structure using conventional surface modification technologies. In this work, oxidation in conjunction with postreaction heat treatment was used to modify the surfaces of porous single-phase NiTi prepared by capsule-free hot isostatic pressing to mitigate Ni leaching and enhance the surface properties. Differential scanning calorimetry thermal analysis, uniaxial compression tests, inductively-coupled plasma mass spectrometry, and cell cultures reveal that porous NiTi alloys oxidized at 450 degrees C for 1 h have an austenite transition temperature below 37 degrees C, excellent superelasticity, lower nickel release, and no cytotoxicity.

Surface characteristics, biocompatibility, and mechanical properties of nickel-titanium plasma-implanted with nitrogen at different implantation voltages

NiTi shape memory alloy is one of the promising orthopedic materials due to the unique shape memory effect and superelasticity. However, the large amount of Ni in the alloy may cause allergic reactions and toxic effects thereby limiting its applications. In this work, the surface of NiTi alloy was modified by nitrogen plasma immersion ion implantation (N-PIII) at various voltages. The materials were characterized by X-ray photoelectron spectroscopy (XPS). The topography and roughness before and after N-PIII were measured by atomic force microscope. The effects of the modified surfaces on nickel release and cytotoxicity were assessed by immersion tests and cell cultures. The XPS results reveal that near-surface Ni concentration is significantly reduced by PIII and the surface TiN layer suppresses nickel release and favors osteoblast proliferation, especially for samples implanted at higher voltages. The surfaces produced at higher voltages of 30 and 40 kV show better adhesion ability to osteoblasts compared to the unimplanted and 20 kV PIII samples. The effects of heating during PIII on the phase transformation behavior and cyclic deformation response of the materials were investigated by differential scanning calorimetry and three-point bending tests. Our results show that N-PIII conducted using the proper conditions improves the biocompatibility and mechanical properties of the NiTi alloy significantly.

In vivo study on biocompatibility and bonding strength of hydroxyapatite-20vol%Ti composite with bone tissues in the rabbit

Biocompatibility and bonding strength of hydroxyapatite-20vol%Ti composite fabricated by hot-pressing technique with bone tissues in the rabbit were investigated by in vivo studies in comparison with those of Ti metal and dense HA ceramic. Although fibrous tissues formed at the interface between the composite and bone tissues at 3 weeks in vivo, bonding strength of the composite increases faster than that of dense HA after 4 weeks. At 3 months in vivo, bonding strength of the composite is higher than that of dense HA and exceeds 6.5 MPa. Moreover, as compared with the visible bonding interfaces between dense HA and new bones, the bonding interfaces for the composite cannot already be distinguished and the composite was osseointegrated fully with bone tissues into one bony body. The shear fracture of bonding strength test for the composite occurred in new bone zones near the interface, which indicates that bonding strength of the composite could even exceed the shear strength of new bones after 3 months in vivo. In conclusion, HA-Ti composite has better osteoconduction and osseointegration abilities than Ti metal and dense HA ceramic after 3 months in vivo and is a promising biomaterial for hard tissue replacement.

Surface characteristics, mechanical properties, and cytocompatibility of oxygen plasma-implanted porous nickel titanium shape memory alloy

Good surface properties and biocompatibility are crucial to porous NiTi shape memory alloys (SMA) used in medical implants, as possible nickel release from porous NiTi may cause deleterious effects in the human body. In this work, oxygen plasma immersion ion implantation (O-PIII) was used to reduce the amount of nickel leached from porous NiTi alloys with a porosity of 42% prepared by capsule-free hot isostatic pressing. The mechanical properties, surface properties, and biocompatibility were studied by compression tests, X-ray photoelectron spectroscopy (XPS), and cell culturing. The O-PIII porous NiTi SMAs have good mechanical properties and excellent superelasticity, and the amount of nickel leached from the O-PIII porous NiTi is much less than that from the untreated samples. XPS results indicate that a nickel-depleted surface layer predominantly composed of TiO(2) is produced by O-PIII and acts as a barrier against out-diffusion of nickel. The cell culturing tests reveal that both the O-PIII and untreated porous NiTi alloys have good biocompatibility.

Fabrication and characteristics of bioactive sodium titanate/titania graded film on NiTi shape memory alloy

A bioactive sodium titanate/titania graded film was formed in situ on NiTi shape memory alloy (SMA) by oxidizing in H(2)O(2) solution and subsequent NaOH treatment and characterized by scanning electron microscopy, Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy (XPS). The bioactivity of the film was investigated using a simulated body fluid (SBF) soaking test. A titania (TiO(2)) layer was first found on NiTi substrate after oxidized in H(2)O(2) solution, and then a porous sodium titanate (Na(2)TiO(3))/titania film with many Ti--OH groups and a trace of Ni(2)O(3) was formed by the reaction of partial TiO(2) phase with NaOH solution. After immersion in SBF for 12 h, apatite was observed to nucleate and grow on the film. With longer soaking time, more apatite appeared on its surface but our control experiments didn't reveal any apatite formation on the chemically polished NiTi SMA, which indicates the bioactivity of NiTi implants could be improved by the formation of the bioactive film. Moreover, XPS depth profiles of O, Ni, Ti, and Na show the bioactive film possesses a smooth graded interface structure to NiTi substrate, which is in favor of sufficient mechanical stability of apatite layer by subsequent deposition in SBF.

First Report of Alternaria raphani Causing Black Patches on Chinese Radish During Postharvest Storage in Canada

During November of 2003, Chinese radishes (Raphanus sativus cv. Taibai) harvested in St. Catharines, Ontario and stored in less than 1°C with 98% relative humidity (RH) and 5°C with 96% RH showed symptoms of black and dark brown, irregular patches, with or without decay. The symptoms were closely associated with skin wounds and damaged root hairs. Fungal DNA was extracted from discolored skin samples peeled from a radish, and 18S rRNA genes were amplified with fungal-specific PCR primers (1) EF4f (5'-ggaagggrtgtatttattag-3') and EF3r (5'-tcctctaaatgaccagtttg-3'). The cloned genes were sequenced using the primer EF4f and compared directly with nonredundant nucleotides in GenBank with BLAST. The results indicated that more than 75% of the fungal microflora on the diseased radish were Alternaria spp. Alternaria sp. was successfully isolated from discolored and decayed radish tissues. Morphological and molecular identification indicated that the isolated Alternaria sp. cultures belong to A. raphani, which was previously reported to cause leaf and pod blight on radish (2). For pathogenicity studies, a spore suspension (1 × 10⁵ conidia/ml) obtained from a 4-week-old A. raphani culture was used to inoculate 'Taibai' Chinese radish tissues, including inner tissues and wounded and nonwounded skin. All tests were carried out at room temperature (22 to 24°C). On inner tissue and wounded skin, symptoms of dark brown-to-black patches appeared 2 days after inoculation and progressed with time. No symptoms developed on the noninoculated control or the nonwounded, inoculated treatment. A. raphani was reisolated from symptomatic tissue. Further evidence of pathogenicity was obtained by an additional inoculation and observation of symptoms. The results indicated that A. raphani was the causal agent of the black patches observed on Chinese radish, and to our knowledge, this is the first report that A. raphani could cause a postharvest disease on Chinese radish in storage. References: (1) J. D. Van Elsas et al. J. Microbiol. Methods 43:133, 2000. (2) M. S. Sangwan et al. J. Mycol. Plant Pathol. 32:125, 2002.

Characterising atherothrombosis in Hong Kong: results of the Hong Kong data from a global atherothrombosis epidemiological survey

OBJECTIVES

To describe the characteristics of patients in Hong Kong with or at risk of atherothrombosis, to determine the proportion of symptomatic patients with more than one vascular bed affected, and to assess the relationship between ankle brachial index and disease severity.

DESIGN

Local participation in an international prevalence study.

SETTING

Five centres in Hong Kong.

PARTICIPANTS

A total of 210 subjects were recruited (105 women and 105 men). Patients were divided into the symptomatic group (with current or previous atherothrombotic symptoms, n=101) and at-risk group (with no current or previous symptoms, but aged over 55 years with at least two specified risk factors, n=109).

MAIN OUTCOME MEASURES

Patient characteristics were described, including the number of arterial beds affected, ankle brachial index, presence of risk factors, and medications taken.

RESULTS

Of the symptomatic patients, 30% had more than one arterial bed involved. A total of 55.4% of the symptomatic group and 18.4% of the at-risk group had abnormal ankle brachial index values. Lower ankle brachial indices were associated with a greater number of affected arterial beds. Diabetes mellitus and hypertension were the most prevalent risk factors in the at-risk group. Symptomatic patients were commonly treated with antihypertensive and antiplatelet agents, whereas at-risk patients were mostly treated with antihypertensive and antidiabetic agents. Only 20% of at-risk patients were taking antiplatelet agents.

CONCLUSIONS

Ankle brachial index is a useful tool for predicting those at risk of atherothrombosis. This simple measurement can be used as part of the screening process in the general practice. The role of antiplatelet agents in primary prevention of atherothrombotic events in at-risk patients deserves further attention.

Regulation of CD1 function and NK1.1(+) T cell selection and maturation by cathepsin S

NK1.1(+) T cells develop and function through interactions with cell surface CD1 complexes. In I-A(b) mice lacking the invariant chain (Ii) processing enzyme, cathepsin S, NK1.1(+) T cell selection and function are impaired. In vitro, thymic dendritic cells (DCs) from cathepsin S(-/-) mice exhibit defective presentation of the CD1-restricted antigen, alpha-galactosylceramide (alpha-GalCer). CD1 dysfunction is secondary to defective trafficking of CD1, which colocalizes with Ii fragments and accumulates within endocytic compartments of cathepsin S(-/-) DCs. I-A(k), cathepsin S(-/-) mice do not accumulate class II-associated Ii fragments and accordingly do not display CD1 abnormalities. Thus, function of CD1 is critically linked to processing of Ii, revealing MHC class II haplotype and cathepsin S activity as regulators of NK T cells.

Inhibition of plant vacuolar H(+)-ATPase by diethylpyrocarbonate

Treatment of the tonoplast H(+)-ATPase from mung bean seedlings (Vigna radiata L.) with histidine-specific modifier, diethyl pyrocarbonate (DEP), caused a marked loss of the ATP hydrolysis activity and the proton translocation in a concentration-dependent manner. The reaction order of inhibition was calculated to be 0.98, suggesting that at least one histidine residue of vacuolar H(+)-ATPase was modified by DEP. The absorbance of the vacuolar H(+)-ATPase at 240 nm was progressively increased after incubation with DEP, suggesting that N-carbethoxyhistidine had been formed. Hydroxylamine, which could break N-carbethoxyhistidine, reversed the absorbance change and partially restored the enzymic activity. The pK(a) of modified residues of vacuolar H(+)-ATPase was kinetically determined to be 6.73, a value close to that of histidine. Thus, it is assuredly concluded that histidine residues of the vacuolar H(+)-ATPase were modified by DEP. Kinetic analysis showed that V(max) but not K(m) of vacuolar H(+)-ATPase was decreased by DEP. This result is interpreted as that the residual activity after DEP inhibition was primarily due to the unmodified enzyme molecules. Moreover, simultaneous presence of DEP and DCCD (N,N'-dicyclohexyl-carbodiimide), an inhibitor modified at proteolipid subunit of vacuolar H(+)-ATPase, did not induce synergistic inhibition, indicating their independent effects. The stoichiometry studies further demonstrate that only one out of four histidine residues modified was involved in the inhibition of vacuolar H(+)-ATPase by DEP. Mg(2+)-ATP, the physiological substrate of vacuolar H(+)-ATPase, but not its analogs, exerted preferentially partial protection against DEP, indicating that the histidine residue involved in the inhibition of enzymatic activity may locate at/or near the active site and directly participate in the binding of the substrate.

IL-15 promotes survival but not effector function differentiation of CD8+ TCRalphabeta+ intestinal intraepithelial lymphocytes

CD8 single-positive cells, including CD8alphaalpha+ and CD8alphabeta+ subsets, constitute the majority of TCRalphabeta+ intestinal intraepithelial lymphocytes (alphabeta iIEL) in mice. CD8+ alphabeta iIEL show significantly weaker responses to TCR stimulation in the presence of exogenous IL-2 than do CD8+ T cells of the central immune system. IL-15 is a T cell growth factor likely expressed in the intestine mucosa. To understand the role of IL-15 in CD8+ alphabeta iIEL biology, we compared the effects of exogenous IL-15 and IL-2 on the survival and primary responses of the two CD8+ alphabeta iIEL subsets in vitro. In contrast to the death of approximately 60% of both CD8alphaalpha+ and CD8alphabeta+ iIEL cultured in IL-2 with or without TCR stimulation, IL-15 promoted survival of the CD8alphaalpha+ subset in the presence of TCR stimulation and promoted survival of both subsets in the absence of TCR stimulation. The higher proliferation level of TCR stimulated CD8alphaalpha+ alphabeta iIEL cultured in IL-15 compared with those cultured in IL-2 is likely due to IL-15's prosurvival effects. In addition, unlike exogenous IL-2, exogenous IL-15 did not support the effector functions of either iIEL subsets, including IFN-gamma production, IL-4-induced Th2 cytokine production, and anti-TCR mAb-redirected cytotoxicity. These findings demonstrate that IL-15 and IL-2 are functionally distinct and suggest that IL-15 plays a unique role in the maintenance of the CD8+ alphabeta iIEL pool in the absence of Ag stimulation and in the survival and expansion of CD8alphaalpha+ alphabeta iIEL upon Ag stimulation.

ECM-stimulated actin bundle formation in embryonic corneal epithelia is tyrosine phosphorylation dependent

Previous studies demonstrated that corneal epithelial cells isolated without basal lamina respond to extracellular matrix (ECM) in an actin dependent manner; the basal cell surface flattens and the actin cortical mat reorganizes. We hypothesize that the actin reorganization is initiated by intracellular signaling mechanisms that includes tyrosine phoshporylation and activation of the Rho, MAP kinase, and PI3 kinase signal transduction pathways. Our goals were to develop a morphological assay to test this hypothesis by answering the following questions: 1) Do the actin bundle formations in the cortical mat have the same configuration in response to different ECM molecules? 2) What is the minimum time ECM molecules need to be in contact with the tissue for the actin to reorganize? 3) Will blocking tyrosine phosphorylation inhibit reorganization of the actin? 4) Are known signal transduction proteins phosphorylated in response to soluble matrix molecules? The actin cortical mat demonstrated distinct bundle configurations in the presence of different ECM molecules. Soluble fibronectin accumulated at the basal cell surfaces 75-fold over 30 min in a clustered pattern. The cells need contact with ECM for a minimum of 10 min to reform the actin bundles at 2 hr. In contrast, two substances that bind to heptahelical receptors to stimulate the Rho pathway, bombesin and lysophosphatidic acid, reorganized the actin bundles in 15-30 min. Focal adhesion kinase, p190 Rho-GAP, tensin, and paxillin were tyrosine phosphorylated in response to soluble fibronectin, type I collagen, or laminin 1. Erk-1, erk-2, and PI3 kinase were activated after 1 hr stimulation by type I collagen. Herbimycin A blocked actin reorganization induced by ECM molecules. In conclusion, we have developed two morphological assays to examine the response of corneal epithelial cells to ECM molecules. In addition, actin bundle reorganization involved tyrosine phosphorylation, MAP kinase, and PI3 kinase activation.

Differential effects of IL-2 and IL-15 on the death and survival of activated TCR gamma delta+ intestinal intraepithelial lymphocytes

TCR gamma delta+ cells are enriched in the intestine mucosa and constitute approximately half of the intestinal intraepithelial lymphocytes (iIEL) in mice. They are likely activated by self and foreign Ags in situ, but little is known about how the activated gamma delta iIEL are regulated. In the iIEL compartment, IL-2 is produced by activated TCR alpha beta+ iIEL, and IL-15 message is detected in iIEL and in the epithelial cells. We found surface expression of IL-2 as well as IL-15Rs on activated gamma delta iIEL, and examined the effects of IL-2 and IL-15 on the survival and death of gamma delta iIEL during secondary stimulation through TCR. We found that both cytokines supported growth of the restimulated gamma delta iIEL, but exerted different effects on their survival. A significant higher number of live cells were recovered from the gamma delta iIEL cultures restimulated in IL-15 than in IL-2. Quantitation of apoptotic cells showed more cell death in the IL-2 group than in the IL-15 group. The cell death was associated with restimulation through TCR and was not caused by insufficient growth factor, thus representing activation-induced cell death. Western blot analyses found no difference in the levels of Bcl-2 and Bax proteins between the two groups. However, the level of Bcl-xL protein diminished with time in the IL-2 group whereas the level was sustained in the IL-15 group, which may contribute to the pro-survival effect of IL-15. These results demonstrated that the survival of activated gamma delta iIEL is differentially regulated by IL-2 and IL-15.

Laparoscopic nephrectomy in a porcine model

Laparoscopic nephrectomy was performed in 15 male pigs, the procedure was successful in 14. Extraction of the intact kidney through a 5-cm lower abdomen incision was done in 7 animals; complete destruction and evacuation of the kidney was accomplished by a round-knife suction device through a 1-cm port in another 7 pigs. Grossly, the specimen consisted of sausage-like tubular renal tissue and a small amount of tissue debris. Pathology revealed that the glomerular and tubular structures were well preserved, no interstitial hematoma could be found. Four ports were usually used, one 1-cm umbilical camera port, one 0.5-cm port for ureter traction, and two 1-cm working ports along the midclavicular line. All the pigs recovered uneventfully. The average operation time was 3 h 20 min. The application of endo-GIA (United States Surgical Corporation) for renal hilum reduced the operative time to 2 h 20 min. Complications included renal vein tear during endoclip application and cutting in the first case, mild subcutaneous emphysema in 2 cases. This first pig received exploratory laparotomy for the repair and ligation of the renal vein. No more major complications occurred with increasing experience. From this porcine experiment, we conclude that the combination of laparoscopy, a tissue destroyer and an endobag for the entrapment of kidney seem to be a promising technique for clinical nephrectomy.

Reduction in lactate accumulation correlates with differentiation-induced terminal cell division of leukemia cells

Lactate accumulation in the medium and glucose utilization decreased during the induction of in vitro differentiation of mouse erythroleukemia (MEL) and human myeloid leukemia (HL-60) cells. The decrease in lactate accumulation occurred as early as 24 h after inducer treatment was initiated and occurred prior to the decrease in glucose utilization. The decrease in lactate accumulation was greater than that predicted by the decrease in glucose utilization, i.e., the ratio of glucose used glycolytically, as measured by lactate accumulation, to glucose used in other pathways ('glycolytic ratio') markedly decreased during differentiation in these cell lines. Differentiation correlated with the abrogation of the high levels of lactate accumulation first described by Warburg as characteristic of some transformed and neoplastic cells. Studies on both parental and differentiation-resistant variant MEL cell lines indicated that the changes in lactate accumulation were not dependent on the changes in glucose utilization and could be dissociated from them. Moreover, the changes in lactate accumulation only occurred in cells able to undergo differentiation-induced terminal cell division. This regulatable expression of lactate accumulation in MEL and HL-60 cells in vitro may make them useful model systems for the elucidation of the molecular mechanisms controlling lactate formation in malignant cells.

Thermoluminescence of 7LiF in therapeutic high linear energy transfer (LET) charged-particle beams

The thermoluminescence of the 200 and 260 degrees C peaks of 7LiF has been measured and compared with off-axis dose and depth-dose distributions for three therapeutic high-LET beams: negative pions, helium ions and neon ions. The methods of analysis consisted of both a single-peak analysis and the dual-peak analysis methods of Hogstrom and Irifune and Hoffmann et al. The results indicate that 7LiF, analysed by the dual-peak analysis methods, is potentially useful for extracting total dose, high-LET dose, and beam quality of helium-ion and negative-pion beams. For the higher-LET neon beam, differences in sensitivity between the 200 and 260 degrees C peaks of 7LiF were found to be independent of variations in LET within the beam; consequently, only the single-peak analysis method is applicable in which case the dosemeter at best can only estimate total dose.

Human chromosome hot points. 1. Hot point at 3p14 in three populations

A chromosome hot point, 3p14, in healthy peasants, mentally retarded patients (MR), and epileptic patients (EP) was studied. The frequency of the hot point, 3p14 break, was significantly higher in EP. It may be caused by folic acid reduction in patients' serum induced by the antiepileptic drugs. The difference between hot point and fragile site is discussed.

A cardiovascular model for studying impairment of cerebral function during +Gz stress

A digital computer model of the human cardiovascular system has been developed which can be used for studying impairment of cerebral function during +Gz stress. The model includes simulation of the arterial and venous systems, the heart, baroreceptor control of heart rate, control of venous tone, and the effect of gravity. Model predictions suggest that, for unprotected subjects, carotid pressure at eye level decreases to 50 mm Hg (beginning of peripheral light loss) at approximately 2.7 Gz. The pressure decreases to 20 mm Hg (beginning of central light loss) at approximately 3.6 Gz. An anti-G suit provides an extra 1.1 to 1.5 Gz protection. Even though blood pressure supplying retinal vessels drops significantly at the above G levels, cerebral blood flow is maintained due to protective and compensatory mechanisms. These observations compare favorably with results reported in the literature. The results suggest that this model can be used to improve our understanding of the cardiovascular system's response to +Gz stress.

K-1 antigen content and the presence of an additional sialic acid-containing antigen among bacteremic K-1 Escherichia coli: correlation with susceptibility to opsonophagocytosis

Eighty percent of blood culture isolates of Escherichia coli K-1 are resistant to in vitro opsonophagocytosis by normal human granulocytes and fresh serum. To determine the basis for susceptibility to phagocytosis in 20% of bacteremic K-1 E. coli, we investigated possible quantitative and qualitative immunochemical differences in the K-1 antigen content among resistant and sensitive isolates. We prepared extracts of blood culture K-1 E. coli by sonication and determined the K-1 polysaccharide content per dry weight of bacteria by rocket immunoelectrophoresis using cross-reactive equine anti-group B meningococcal sera. We assessed qualitative differences in the antigen content by crossed immunoelectrophoresis, using an immune globulin fraction and isolated immunoglobulin G (IgG) and IgM from the group B antisera. Three different resistant K-1 isolates contained a mean K-1 content of 48.5 +/- 7.6 mug/mg +/- standard deviation of dry bacteria, and three sensitive isolates contained 23.2 +/- 5.6 mug/mg (P < 0.005). Crossed immunoelectrophoresis of extracts from both sensitive and resistant strains revealed a secondary sialic acid-containing antigen that was electrophoretically different from both the major K-1 antigen and a reference group B meningococcal antigen. This negatively charged secondary antigen was susceptible to Clostridium perfringens neuraminidase degradation and reacted only with IgG whereas the major K-1 antigen reacted only with IgM. This antigen was detected in the extracts of resistant isolates only at 10(10) but not at 10(9) colony-forming units per milliliter. This study demonstrates that (i) the degree of phagocytosis of bacteremic E. coli K-1 isolates is inversely associated with K-1 content, and (ii) more easily phagocytosed (sensitive) K-1 isolates have greater amounts of an additional sialic acid-containing antigen that appears to be unrelated to the previously described O acetyl K-1 antigen.

A direct radioimmunoassay for human renin substrate and identification of multiple substrate types in plasma

Plasma renin substrate, a widely measured parameter of the renin reaction, is quantitated indirectly by the measurement of liberated angiotensin I upon exhaustive incubation of plasma with added renin. To overcome methodological problems of this assay system, we have developed a direct radioimmunoassay for this plasma protein using renin substrate purified from pooled plasma of normotensive subjects as the antigen. Comparison of substrate quantitated by the two assay systems (direct and indirect) indicates a 1:1 correlation with the exception of certain subjects with elevated substrate levels induced by estrogen therapy. To study the possibility of multiple substrate forms, we have made a comparison of substrate quantitated by both radioimmunoassays in conjunction with electrophoresis of plasma on polyacrylamide gel. One major form of substrate with a retardation factor (Rf) = 0.60 was found in normotensive and essential hypertensive subjects which gave a 1:1 correspondence on quantitation by the two methods. In contrast, six of 16 women on oral contraceptives demonstrated three forms of substrate (Rf = 0.16, 0.35, and 0.60) on electrophoresis. Substrate with Rf = 0.16 and 0.35 did not cross-react with the antiserum prepared against substrate from normotensive subjects, implying structural differences in these proteins.

Purification and partial characterization of human angiotensinogen

Renin substrate was initially extracted from human plasma by (NH4)2SO4 followed by chromatography on Sephadex G-150, DEAE cellulose, calcium phosphate gel, isoelectric focusing and preparative polyacrylamide gel electrophoresis. On the basis of one mol of angiotensin per mol of substrate, the purity of the preparation is in excess of 95%. On analytical polyacrylamide gel electrophoresis in the presence of 1% sodium dodecyl sulfate or 8 M urea, the protein appears homogenous. In addition, the purified protein shows only one preciptin line against anti-normal human serum on either Ouchterlony immunodiffision or immunoelectrophoresis. The biological activity appears similar to "native" renin substrate since the Km is the same as that reported for the renin reaction in whole plasma. The molecular weight was determined as 110 000 by gel filtration and polyacrylamide gel electrophoresis; amino acid analysis of the human substrate differs from that reported for hog, especially in the Asp, Glu and Gly composition.

Adolescent Morality: Its Differentiated Structure And Relation To Delinquent Conduct

Cluster analysis of a moral values scale based on responses of 100 matched pairs of delinquent (D) and nondelinquent (ND) boys of high school age revealed 4 highly reliable dimensions: 1) Informing or "snitching", 2 )Masculine inadequacy, 3) Identity conflict, and 4) Aggression. On these matched as well as on replicated samples, the results showed that the D SS consider informing on others as more wrong than the ND Ss, while the ND Ss judged behaviors associated with identity conflict as more wrong than the D Ss. Non-significant relationships were found between the moral value dimensions and age, race, social status and verbal intelligence. The results were discussed in relation to previously postulated assumptions concerning the global nature of morality and the direct relation of verbalized moral values and moral behavior. The results were interpreted as being partially consistent with the notion that the delinquent is not necessarily ignorant of societal values but rather becomes committed to or adopts the values of the deviant subculture.