Metabolic habitat imaging with hemodynamic heterogeneity predicts individual progression-free survival in high-grade glioma

AIM

We design a feasibility study to obtain a set of metabolic-hemodynamic habitats for tackling tumor spatial metabolic patterns with hemodynamic information.

MATERIALS AND METHODS

Preoperative data from 69 high-grade gliomas (HGG) patients with subsequent histologic confirmation of HGG were prospectively collected (January 2016 to March 2020) after concurrent chemoradiotherapy (CCRT). Four vascular habitats were automatically segmented by multiparametric magnetic resonance imaging (MRI). The metabolic information, either at enhancing or edema tumor regions, was obtained by two neuroradiologists. The relative habitat volumes were used for weight estimation procedures for computing the coefficients of a linear regression model using weighted least squares (WLS) for metabolite semiquantifications (i.e. the Cho/NAA ratio and the Cho/Cr ratio) at vascular habitats. Multivariate Cox proportional hazard regression analyses are used to obtain the odds ratio (OR) and develop a nomogram using weighted estimators corresponding to each covariate derived from Cox regression coefficients.

RESULTS

There was a strongly correlation between perfusion indexes and the Cho/Cr ratio (rCBV, r=0.71) or Cho/NAA ratio (rCBV, r=0.66) at high-angiogenic enhancing tumor habitats (HAT) habitat. Compared isocitrate dehydrogenase (IDH) mutation to their wild type, the IDH wild type had significantly decreased Cho/Cr ratio (IDH mutation: Cho/Cr ratio = 2.44 ± 0.33, IDH wildtype: Cho/Cr ratio = 2.66 ± 0.36, p=0.02) and Cho/NAA ratio (IDH mutation: Cho/Cr ratio = 4.59 ± 0.61, IDH wildtype: Cho/Cr ratio = 4.99 ± 0.66, p=0.022) at the HAT. The C-index for the median progression-free survival (PFS) prediction was 0.769 for the Cho/NAA nomogram and 0.747 for the Cho/Cr nomogram through 1000 bootstrapping validation.

CONCLUSIONS

Our findings suggest that spatial metabolism combined with hemodynamic heterogeneity is associated with individual PFS to HGG patients post-CCRT.

[Comparison on the clinical characteristics of patients with Takotsubo syndrome from China and from Europe/North America]

Objective: To summarize the clinical characteristics of patients with Takotsubo syndrome (TTS) from China and compare these features with patients from Europe/North America. Methods: We reviewed case reports published between 1990 and 2020 with the key words of "Takotsubo syndrome" "stress cardiomyopathy" "apical balloon syndrome" and "broken heart syndrome", in Wanfang, CNKI, Pubmed and Web of Science databases, and 1 294 articles were identified, including 128 articles reporting 163 cases in China and 1 166 articles reporting 1 256 cases in Europe/North America. The characteristics of demographics, triggers, symptoms, electrocardiogram, echocardiography, left ventriculogram,coronary angiography, treatment and prognosis were analyzed and compared between Chinese and European/North American cases. Results: A total of 1 294 articles (1 419 cases: 163 from China, 1 256 from Europe/North America) were included in the final analysis. The characteristics of Chinese cases included: (1) demographic:the age was (59.6±16.9) years, which was similar with that of European/North American ((59.7±17.4) years, P=0.90), and female accounting for 78.5% (128/163), which was lower than that of European/North American (85.4% (1 073/1 256), P=0.02). (2) Triggers:mental triggers accounted for 48.5% (79/163), physical triggers accounted for 43.6% (71/163), and no triggers accounted for 7.9% (13/163), respectively. Compared with Europe/North America, the ratio of patients with mental triggers was higher in China, while the ratio of patients with physical triggers and no triggers was lower (P<0.05). (3) Symptoms: chest pain (52.8% (86/163)), chest tightness (35.0% (57/163)), shortness of breath (33.1% (54/163)), dizziness (16.0% (26/163)), sweating (15.3% (25/163)), palpitations (12.3% (20/163)), syncope (9.2% (15/163)) abdominal pain/diarrhea (8.6% (14/163)), hypotension (7.4% (12/163)), and fatigue (1.2% (2/163)) were illustrated in sequence. Compared with patients in Europe/North America, the ratio of patients with chest tightness, dizziness, sweating, palpitations, abdominal pain/diarrhea was higher in Chinese patients, while the ratio of patients with hypotension was lower in Chinese patients (P<0.05). (4) Electrocardiogram: main manifestations were myocardial ischemia symptoms, such as ST-segment elevation (63.8% (104/163)), T wave inversion (46.0% (75/163)), ST-segment depression (8.6% (14/163)). Compared with European/North American, the ratio of patients with ST-segment elevation, T wave inversion, and atrioventricular block was higher in Chinese patients (P<0.05). (5) Echocardiography and imaging:apical dyskinesia (59.5% (97/163)) and apical/left ventricular bulbar dilation (36.2%(59/163)) dominated the echocardiography findings. Compared with European/North American, the ratio of patients with apical dyskinesia, apical/left ventricular bulbar dilation, and mitral regurgitation was higher in Chinese patients, while the ratio of patients with dyskinesia in other parts and left ventricular ejection fraction<50% was lower in Chinese patients (P<0.05). Left ventricular angiography showed 36.2% (59/163) of apical dyskinesia in Chinese patients, which was higher than that reported in European/North American patients, and 38.7% (63/163) of apical/left ventricular bulbar dilation was reported in Chinese patients, which was similar to that reported in European/North American patients. Coronary angiography showed percent of no stenosis or stenosis less than 50% was 87.1% (142/163), which was similar to that reported in European/North American patients (P>0.05). The typical type of TTS accounted for 96.3% (157/163), which was significantly higher than that reported in European/ American patients, while the ratio of basal type and midventricular type was lower (P<0.01). (6) Treatment and prognosis:the applied drugs in China were listed in order as following, β-blockers (41.1% (67/163)), antiplatelet agents (37.4%(61/163)), ACEI/ARB (36.2%(59/163)), anticoagulants (27.0%(44/163)), diuretics (19.6% (32/163)), etc. Compared with Europe/North America, the ratio of antiplatelet agents, anticoagulants, statins, diuretics, and nitrates use was higher in China (P<0.05), while the use of oxygen therapy and IABP was similar (P>0.05). The hospital mortality in China was 5.5% (9/163), during 1-year follow-up the recurrence rate was 3.7% (6/163) and the mortality was 0. The prognosis was similar with that in Europe/North America. Conclusions: Compared with TTS cases in Europe/North America, TTS cases in China also occur usually in middle-aged and elderly women, most of whom have mental/physical triggers and typical imaging manifestations, followed by a low hospital mortality rate and recurrence rate.

A novel biocomposite scaffold with antibacterial potential and the ability to promote bone repair

Clinical treatment of bone defects caused by trauma, tumor resection and other bone diseases, especially bone defects that can lead to infection, remains a major challenge. Currently, autologous bone implantation is the gold standard for treatment of bone defects, but it is limited by secondary trauma and insufficient autologous material. Moreover, postoperative infection is an important factor affecting bone healing.AcN-RADARADARADARADA-CONH2 (RADA) is a new type of self-assembling peptide(SAP) composed of Arg,Ala,Asp and other amino acids was designed and prepared. The "RADA" self-assembling peptide hydrogels has excellent biological activity and it's completely biodegradable and non-toxic.It is also have been confirmed to promote cell proliferation, wound healing, tissue repair, and drug delivery. To promote bone regeneration and simultaneously prevent bacterial infection, we designed biocomposite scaffolds comprising RADA and calcium phosphate cement (CPC), termed RADA-CPC. The morphological features of the scaffold were characterized by scanning electron microscopy (SEM). In vitro studies demonstrated that RADA-CPC enhances osteoblast proliferation, differentiation and mineralization. In addition, the scaffold was used as a drug delivery system to treat postoperative infections by sustained release of ciprofloxacin (CIP). The RADA-CPC scaffold may have potential application prospects in orthopedics field because of its role in promoting bone repair and as a sustained-release drug carrier to prevent infections.

Arbuscular mycorrhizal fungi improve the growth and disease resistance of the invasive plant Wedelia trilobata

AIMS

Arbuscular mycorrhizal fungi (AMF) are symbiotic partners of many invasive plants, however, it is still unclear how AMF contribute to traits that are important for the successful invasion of their host and how environmental factors, such as nutrient conditions, influence this. This study was to explore the effects of Glomus versiforme (GV) and Glomus mosseae (GM) on the growth and disease resistance of the invasive plant Wedelia trilobata under different nutrient conditions.

METHODS AND RESULTS

We found that GV and GM had higher root colonization rates resulting in faster W. trilobata growth under both low-N and low-P nutrient conditions compared to the normal condition. Also, the colonization of W. trilobata by GV significantly reduced the infection area of the pathogenic fungus Rhizoctonia solani under low-N conditions.

CONCLUSIONS

These results demonstrated that AMF can promote the growth and pathogenic defence of W. trilobata in a nutrient-poor environment, which might contribute to their successful invasion into certain type of habitats.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, we report for the first time that AMF can promote growth and disease resistance of W. trilobata under nutrient-poor environment, which contribute to a better understanding of plant invasion.

Enzyme responsive titanium substrates with antibacterial property and osteo/angio-genic differentiation potentials

After implantation into a host, titanium (Ti) orthopaedic materials are facing two major clinical challenges: bacterial infection and aseptic loosening, which directly determine the long-term survival of the implant. To endow Ti implant with self-defensive antibacterial properties and desirable osteo/angio-genic differentiation potentials, hyaluronic acid (HA)-gentamicin (Gen) conjugates (HA-Gen) and chitosan (Chi) polyelectrolyte multilayers were constructed on deferoxamine (DFO) loaded titania nanotubes (TNT) substrates via layer-by-layer (LBL) assembly technique, termed as TNT/DFO/HA-Gen. The HA-Gen conjugate was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (¹H NMR). The physicochemical properties of the substrates were characterized by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The on-demand DFO release was associated with the degradation of multilayers triggered by exogenous hyaluronidase, which indicated enzymatic and bacterial responsiveness. The TNT/DFO/HA-Gen substrates displayed effective antifouling and antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), while were favourable for the adhesion, proliferation and osteo/angio-genic differentiation of mesenchymal stem cells (MSCs). The multifaceted drug-device combination (DDC) strategy showed potential applications in orthopaedic fields.

Phenotypic analysis of atopic dermatitis in children aged 1-12 months: elaboration of novel diagnostic criteria for infants in China and estimation of prevalence

BACKGROUND

Atopic dermatitis (AD) is the most common skin disorder in infancy. However, the diagnosis and definite significance of infantile AD remains a debated issue.

OBJECTIVE

To analyse the phenotypes of AD in infancy, to establish diagnostic criteria and to estimate the prevalence of this condition in China.

METHODS

This is a multicentric study, in which 12 locations were chosen from different metropolitan areas of China. Following careful and complete history-taking and skin examination, the definite diagnosis of AD was made and the severity based on the SCORAD index was determined by local experienced dermatologists. Based on the detailed phenotyping, the major and representative clinical features of infantile AD were selected to establish the diagnostic criteria and evaluate their diagnostic efficacy.

RESULTS

A total of 5967 infants were included in this study. The overall point prevalence of AD was 30.48%. The infantile AD developed as early as at the second month of life, and its incidence peaked in the third month of life at 40.81%. The proportion of mild, moderate and severe AD was 67.40%, 30.57% and 2.03%, respectively. The most commonly seen manifestations in the infantile AD were facial dermatitis (72.07%), xerosis (42.72%) and scalp dermatitis (27.93%). We established the novel diagnostic criteria of infants, which included: (i) onset after 2 weeks of birth; (ii) pruritus and/or irritability and sleeplessness comparable with lesions; and (iii) all two items above with one of the following items can reach a diagnosis of AD: (i) eczematous lesions distributed on cheeks and/or scalp and/or extensor limbs, and (ii) eczematous lesions on any other parts of body accompanied by xerosis.

CONCLUSIONS

In China, the prevalence of AD in infancy is 30.48% according to clinical diagnosis of dermatologists. The novel Chinese diagnostic criteria for AD in infants show a higher sensitivity and comparable specificity.

Magnetic resonance spectroscopy may serve as a presurgical predictor of somatostatin analog therapy response in patients with growth hormone-secreting pituitary macroadenomas

PURPOSE

Somatostatin analogs (SSAs) are considered one of the most effective medical treatments for patients with growth hormone-secreting pituitary adenomas (GH-PAs). The postoperative electron microscopy (EM) pathological subtype and SSTR2 expression in the tumor are the most established predictors of patient response to SSA therapy. The aim of this study was to evaluate how will magnetic resonance spectroscopy (MRS) measurements before surgery predict the EM pathological subtypes and SSTR2 expression of tumors, and thereby serve as an indicator for the therapeutic sensitivity to SSAs of patients with GH-PAs.

METHODS

Eighteen patients with GH pituitary macroadenomas who underwent transsphenoidal surgery were included in this retrospective study. The preoperative MRS data and T2 signal intensity were obtained from patients by 1.5 T MR spectroscopy of the sellar mass. The EM pathological subtypes of tumors were determined after surgery through examination of cell granulations. The expressions of somatostatin receptor 2 (SSTR2), SSTR5, P21, P27, and Ki-67 were evaluated by immunohistochemistry.

RESULTS

The MRS parameters that were found to significantly predict the EM pathological subtypes of tumors, as calculated by the receiver operating characteristic curve, were the choline (Ch) value at 3140.5 MR units (sensitivity 69.2%, specificity 100%) and the choline/creatine (Ch/Cr) ratio at 1.27 (sensitivity 92.3%, specificity 100%). Further, the Ch/Cr ratio, but not other MRS data, was shown to negatively correlate with the expression of SSTR2 (P = 0.02). The Ch/Cr ratio was also found to positively correlate with the Ki-67 value (P < 0.05) and T2 signal (P < 0.05), but not with other factors that were examined in this study. Moreover, the Ch/Cr ratio could predict the EM pathological subtypes of tumors with an accuracy of 83.3% (5/6) for patients with an isointense T2 signal.

CONCLUSION

The Ch/Cr ratio by MRS could effectively predict the tumor subtype and was significantly correlated with the expression of SSTR2, which was consistent with other predictors. It was also able to distinguish the patients with isointense T2 signals. Our results provide a potentially new and non-invasive method to predict the response to SSAs in patients with GH pituitary macroadenomas.

[Effects of 3-methyladenine on airway inflammation, airway hyperresponsiveness and mucus secretion in asthmatic mice]

Objective: To investigate the effects of 3-methyladenine on airway inflammation, airway hyperresponsiveness and mucus secretion in asthmatic mice, and to explore its mechanism. Methods: C57BL/6J female mice were randomly divided into normal control group (PBS), OVA group(OVA), OVA with 3-methyladenine group (OVA+3-MA), and OVA with 4-phenylbutyrate group (OVA+4-PBA). OVA group, OVA+3-MA group and OVA+4-PBA groups were all sensitized and challenged with OVA to establish asthmatic models, while PBS group was given PBS as a control. At 2 h before challenge, OVA+3-MA group was intraperitoneally injected with 3-methyladenine, and OVA+4-PBA group was intraperitoneally injected with 4-phenylbutyrate. Airway hyperresponsiveness, eosinophils, and pathological changes of pulmonary tissue (hematoxylin-eosin, HE staining) were measured to confirm the establishment of asthmatic models. Sections of pulmonary tissue were also stained with Masson and PAS. The expression level of LC3B was measured by immunofluorescence and Western blot. The Beclin1, Muc5ac, Atf6, Chop and Bip proteins in lung tissues were detected by Western blot. Results: The Penh value, and eosinophils in BALF in OVA group was significantly increased compared with PBS group (P<0.05). The Penh value in OVA+3-MA group and OVA+4-PBA group were significantly decreased compared with the OVA group at the concentration of 6.25 g/L, 12.50 g/L, 25.00 g/L, and 50.00 g/L of methacholine (all the P<0.05), and the eosinophils were also significantly decreased compared with the OVA group (P<0.05). Pulmonary histology revealed that OVA group showed high levels of inflammatory cell infiltration of bronchi and lung vessels, alveolar septal thickening, structural destruction, smooth muscle thickening, collagen deposition, and goblet cell hyperplasia. The levels of inflammatory cell infiltration of bronchi and lung vessels, alveolar septal thickening, structural destruction, smooth muscle thickening, collagen deposition, and goblet cell hyperplasia in OVA+3-MA group and OVA+4-PBA group were significantly lower than the OVA group, while the PBS group was normal. Compared with PBS group, the expression of LC3 Ⅱ/Ⅰ, Beclin1, Muc5ac, Atf6, Chop and Bip proteins in lung tissues in the OVA group were significantly increased (1.09±0.04 vs 0.34±0.09, P<0.05; 0.18±0.01 vs 0.06±0.01, P<0.05; 1.90±0.38 vs 0.46±0.11, P<0.05; 1.67±0.18 vs 0.41±0.08, P<0.05; 2.96±0.45 vs 1.11±0.10, P<0.05; 2.07±0.34 vs 0.49±0.17, P<0.05, respectively). Compared with the OVA group the expression of LC3 Ⅱ/Ⅰ, Beclin1, Muc5ac, Atf6, Chop and Bip proteins in lung tissues in the OVA+3-MA group and OVA+4-PBA group were significantly decreased (0.46±0.07 vs 1.09±0.04, 0.63±0.03 vs 1.09±0.04, both P<0.05; 0.11±0.02 vs 0.18±0.01, 0.12±0.02 vs 0.18±0.01, both P<0.05; 0.72±0.22 vs 1.90±0.38, 0.57±0.13 vs 1.90±0.38, both P<0.05; 1.06±0.12 vs 1.67±0.18, 1.02±0.12 vs 1.67±0.18, both P<0.05; 1.67±0.21 vs 2.96±0.45, 1.10±0.15 vs 2.96±0.45, both P<0.05; 1.03±0.11 vs 2.07±0.34, 0.97±0.10 vs 2.07±0.34, both P<0.05). Conclusion: 3-MA was shown to inhibit airway inflammation, airway hyperresponsiveness and mucus secretion in mice with bronchial asthma, and the mechanism may be related to inhibiting autophagy, and then inhibiting endoplasmic reticulum stress.

N-halamine-based multilayers on titanium substrates for antibacterial application

Bacterial infection is one of the most severe postoperative complications leading to clinical orthopedic implants failure. To improve the antibacterial property of titanium (Ti) substrates, a bioactive coating composed of chitosan-1-(hydroxymethyl)- 5,5-dimethylhydantoin (Chi-HDH-Cl) and gelatin (Gel) was fabricated via layer-by-layer (LBL) assembly technique. The results of Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (¹HNMR) and X-ray photoelectron spectroscopy (XPS) showed that Chi-HHD-Cl conjugate was successfully synthesized. Scanning electron microscopy (SEM), atomic force microscope (AFM) and water contact angle measurements were employed to monitor the morphology, roughness changes and surface wettability of Ti substrates, which proved the multilayers coating formation. Antibacterial assay against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) revealed that the Gel/Chi-HDH-Cl modified Ti substrates most efficiently inhibited the adhesion and growth of bacteria. Meanwhile, in vitro cellular tests confirmed that Gel/Chi-HDH-Cl multilayers had no obvious cytotoxicity to osteoblasts. The study thus provides a promising method to fabricate antibacterial Ti-based substrates for potential orthopedic application.

Deferoxamine loaded titania nanotubes substrates regulate osteogenic and angiogenic differentiation of MSCs via activation of HIF-1α signaling

To develop biomaterials for inducing osteogenic and angiogenic differentiation of mesenchymal stem cells (MSCs) is crucial for bone repair. In this study, we employed titania nanotubes (TNT) as drug nanoreservoirs to load deferoxamine (DFO), and then deposited chitosan (Chi) and gelatin (Gel) multilayer as coverage structure via layer-by-layer (LBL) assembly technique, resulting in TNT-DFO-LBL substrates. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements were employed to characterize the physical and chemical properties of the substrates. The results proved the successful fabrication of multilayer coating on TNT array. DFO released from the TNT arrays in a sustained manner. The drug-device combination titanium (Ti) substrates positively improved the adhesion, proliferation, osteogenic/angiogenic differentiation of MSCs and mediated the growth behavior of human umbilical vein endothelial cells (HUVECs). Moreover, the TNT-DFO-LBL substrates up-regulated osteogenic and angiogenic differentiation related genes expression of MSCs by activating HIF-1α signaling pathway. The approach presents here has a potential impact on the development of high quality Ti-based orthopedic implants.

Osteogenesis of 3D printed porous Ti6Al4V implants with different pore sizes

Selective laser melting (SLM) is one of the three-dimensional (3D) printing techniques that manufacturing versatile porous scaffolds with precise architectures for potential orthopedic application. To understand how the pore sizes of porous Ti6Al4V scaffolds affect their biological performances, we designed and fabricated porous Ti6Al4V implants with straightforward pore dimensions (500, 700, and 900 µm) via SLM, termed as p500, p700, and p900 respectively. The morphological characteristics of Ti6Al4V scaffolds were assessed showing that the actual pore sizes of these scaffolds were 401 ± 26 µm, 607 ± 24 µm, 801 ± 33 µm, respectively. The mechanical properties of Ti6Al4V scaffolds were also evaluated showing that they were comparable to that of bone tissues. Meanwhile, the effect of pore size on biological responses was systematically investigated in vitro and in vivo. It was verified that 3D printing technique was able to fabricate porous Ti6Al4V implants with proper mechanical properties analogous to human bone. The in vitro results revealed that scaffolds with appropriate pore dimension were conducive to cell adhesion, proliferation and early differentiation. Furthermore, the porous Ti6Al4V scaffolds were implanted into the rabbit femur to investigate bone regeneration performance, the in vivo experiment showed the p700 sample was in favor of bone ingrowth into implant pores and bone-implant fixation stability. Taken together, the biological performance of p700 group with actual pore size of about 600 µm was superior to other two groups. The obtained findings provide basis to individually design and fabricate suitable porous Ti6Al4V with specific geometries for orthopedic application.

Alendronate-loaded hydroxyapatite-TiO2 nanotubes for improved bone formation in osteoporotic rabbits

Alendronate-loaded hydroxyapatite-TiO₂ nanotubes were fabricated for locally improving new bone formation at the bone–implant interface in osteoporotic rabbits.

Influence of strontium ions incorporated into nanosheet-pore topographical titanium substrates on osteogenic differentiation of mesenchymal stem cells in vitro and on osseointegration in vivo

Strontium ions incorporation and nanosheet-pore topography of titanium substrates synergistically improve the osteogensis of MSCs and osseointegration in vivo.

Multifunctional Fe2O3@PPy-PEG nanocomposite for combination cancer therapy with MR imaging

In recent years, magnetic hyperthermia nanoparticles have drawn great attention for cancer therapy because they have no limitation of tissue penetration during the therapy process. In this study, cubic nanoporous Fe2O3 nanoparticles derived from cubic Prussian blue nanoparticles were used as magnetic cores to generate heat by alternating the current magnetic field (AMF) for killing cancer cells. In addition, polypyrrole (PPy) was coated on the surfaces of the cubic Fe2O3 nanoparticles to load doxorubicin hydrochloride (DOX). The PEG component was then physically adsorbed onto the surfaces of the nanoparticles, resulting in a Fe2O3@PPy-DOX-PEG nanocomposite. The nanocomposite was triggered by acid stimulus and AMF to release DOX, resulting in a remarkable combination therapeutic effect via chemotherapy and magnetic hyperthermia. Furthermore, the nanocomposite could realize magnetic resonance imaging (MRI) due to the magnetic core structure. The study provides an alternative for the development of new nanocomposites for combination cancer therapy with MR imaging in vivo.

Regulation of the biological functions of osteoblasts and bone formation by Zn-incorporated coating on microrough titanium

To improve the biological performance of titanium implant, a series of Zn-incorporated coatings were fabricated on the microrough titanium (Micro-Ti) via sol-gel method by spin-coating technique. The successful fabrication of the coating was verified by combined techniques of scanning electron microscopy, surface profiler, X-ray diffraction, X-ray photoelectron spectroscopy, and water contact angle measurements. The incorporated zinc existed as ZnO, which released Zn ions in a sustained manner. The Zn-incorporated samples (Ti-Zn0.08, Ti-Zn0.16, and Ti-Zn0.24) efficiently inhibited the adhesion of both Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria. The in vitro evaluations including cell activity, alkaline phosphatase (ALP), mineralization, osteogenic genes expressions (Runx2, ALP, OPG, Col I, OPN, and OC), and tartrate-resistant acid phosphatase, confirmed that Ti-Zn0.16 sample was the optimal one to regulate the proliferation or differentiation for both osteoblasts and osteoclasts. More importantly, in vivo evaluations including Micro-CT analysis, push-out test, and histological observations verified that Ti-Zn0.16 implants could efficiently promote new bone formation after implantation for 4 and 12 weeks, respectively. The resulting material thus has potential application in orthopedic field.

Influence of the titania nanotubes dimensions on adsorption of collagen: an experimental and computational study

To investigate the influence of the titanium nanotube (TiNT) diameters on the adsorption of collagen type I (Col-I), TiNTs with different diameters were prepared with anodization. The adsorption amount of Col-I on the different TiNTs substrates was evaluated by spectrophotometric measurement and immunofluorescence staining, respectively. The results showed that the diameters of TiNTs played a key role in the adsorption process of Col-I. TiNTs with diameters around 100nm displayed a higher adsorption amount and faster adsorption speed than that of 30nm TiNTs. Furthermore, more collagen molecules were aggregated in the tubes of 100nm TiNTs. Molecular dynamics simulation was performed to elucidate the adsorption mechanism. The simulation results confirmed that physical adsorption was the main driving force, including van der Waals force and hydrogen bond between Col-I molecules and TiNTs. The calculated interaction energies indicated that the TiNTs with bigger dimensions had higher interaction energies, thus leading to the higher collagen adsorption.

Cell cycle arrest of Jurkat cells by leukemic bone marrow stromal cells: possible mechanisms and involvement of CRIF1

Bone marrow hemopoietic microenvironment plays an important role in the incidence and development of leukemia. Studies using normal bone marrow stromal cells (BMSCs) and an established stromal cell line, have shown that the leukemic cell cycle can be arrested in the G0/G1 phase in BMSCs, although the mechanism is still unclear. We performed this study to determine the effect of primary cultured leukemic BMSCs on the cell cycle distribution of Jurkat cells. Normal and leukemic BMSCs were isolated for culture to create a hematopoietic microenvironment simulating bone marrow in vitro. The normal and leukemic BMSCs induced cell cycle arrest of Jurkat cells in the G0/G1 phase. Suppression subtractive hybridization revealed differential gene expression after the co-culture of cells with normal and leukemic BMSCs. Jurkat cells showed upregulated expression of genes involved in cell cycle control CR6 interacting factor 1 (CRIF1). Reverse transcriptase polymerase chain reaction results also showed increased CRIF1 mRNA levels in Jurkat cells co-cultured with either normal BMSCs or leukemic BMSCs compared with a suspension culture group: 5.16 ± 0.75, 6.13 ± 0.63 versus 3.02 ± 0.32, respectively (P < .05). These results indicated cell cycle arrest of Jurkat cells in the G0/G1 phase to be induced by primary cultured leukemic BMSCs associated with increased expression of CRIF1 by leukemic cells.

Observation of a change of vibrational excitation mechanism with surface temperature: HCl collisions with Au(111)

We have measured the vibrational excitation probability (Pv) of HCl incident on a Au(111) surface at kinetic energies (Ei) of 0.59 eV to 1.37 eV and surface temperatures (Ts) of 273 K to 1073 K. For all energies, the slope of the Pv as a function of Ts exhibits a sharp increase above Ts approximately 800 K. We show this change in slope and the threshold behavior of Pv to be consistent with a change in excitation mechanism from an electronically adiabatic mechanical mechanism to an electronically nonadiabatic mechanism involving excited electron-hole pairs.

Characterization of a novel zinc finger gene with increased expression in nondividing normal human cells

We report here the cloning and characterization of a novel KRAB zinc finger gene, ZFQR, which has eight tandemly repeated zinc fingers, a complete KRAB box at the N-terminal region, and a unique C-terminal sequence. It is expressed in a variety of human tissues, and mRNA levels are upregulated in nondividing senescent and quiescent human fibroblasts. Overexpression of the protein in quiescent cells stimulated with serum growth factors results in inhibition of entry into the cell cycle. The latter activity is lost when the N-terminal KRAB domain is deleted. The KRAB domain is also required for the transcriptional repression activity of ZFQR and in maintaining association of the protein with the nuclear matrix. The gene has been mapped to human chromosome 19q13.4. The association of ZFQR with the nuclear matrix, transcriptional repression activity, increased expression in senescent and quiescent cells, and the ability to inhibit quiescent cells stimulated with growth factors from entering the cell cycle suggests a role for ZFQR in the maintenance of the nondividing state of normal human cells.

Filtering theory and application of wavelet optics at the spatial-frequency domain

We propose a wave-front filtering concept of wavelet optics and present its associated theory of wavelet optics. We analyze the filtering phenomenon of wavelet optics at the spatial-frequency domain-multiscale edge detection and multiscale feature recognition-using the theory, and we also perform the analysis with the Mexican-hat wavelet and the Haar wavelet. By use of our theory, information is obtained from an optical image that is processed multiscalely and delicately by stretching and translation of the factors. With this technique it is possible to perform real-time programming in information processing in a mixed optical system.

Identification of an alternatively spliced form of the Tat interactive protein (Tip60), Tip60(beta)

Tip60 was originally isolated as a Tat interactive protein. It was subsequently shown that Tip60 had histone acetyltransferase (HAT) activity. In studies to understand gene-expression regulation that might involve HAT activity, we PCR-amplified Tip60 from a human heart marathon-ready cDNA library. As a result, we identified an alternatively spliced form of Tip60, Tip60beta (we refer to the previously cloned Tip60 as Tip60alpha). Tip60beta cDNA is slightly smaller than Tip60alpha, and sequencing indicates that there is a deletion of 156 bp in the coding region of the gene. The predicted Tip60beta protein therefore lacks 52 amino acids when compared with Tip60alpha. The Tip60alpha gene is encoded by 14 exons, and Tip60beta is an alternatively spliced form resulting from the exclusion of exon 5 during the splicing process. Exon 5 encodes a proline-rich region that is known to be important for protein-protein interaction. Tip60beta is expressed in a variety of human tissues and cell lines, and the protein is present in both the nucleus and cytoplasm in contrast to Tip60alpha, which is entirely nuclear. The results suggest that Tip60beta may have functions additional to those of Tip60alpha in cells and tissues.

Near-Infrared Laser Spectroscopy of TiS: The b(1)Pi-X(3)Delta Transition

Laser-induced fluorescence spectrum of TiS in the 769-863 nm region has been recorded and analyzed. The TiS molecule was produced using the technique of laser vaporization/reaction with supersonic cooling. Twenty-one weak subbands have been assigned as being due to b(1)Pi-X(3)Delta, B(3)Pi(0)-X(3)Delta(1), and C(3)Delta-X(3)Delta transitions. Strong evidence shows that the b(1)Pi state is responsible for perturbing the v = 0, 1, and 2 levels of the C(3)Delta(1) subband. The molecular constants of the b(1)Pi state have been determined as follows: T(e) = 10 589.47 cm(-1), omega(e) = 542.14 cm(-1), omega(e)x(e) = 3.16 cm(-1), B(e) = 0.19568 cm(-1), and alpha(e) = 0.00085 cm(-1). The spin-orbit interaction between the b(1)Pi (v = 2 and 3) and C(3)Delta (v = 1 and 2) levels is discussed in terms of configuration interaction occurring between the b(1)Pi from the 11varsigma(1) 5pi(1) configuration and the (1)Pi from the 5pi(1) 1delta(1) configuration, and the C(3)Delta state from 12varsigma(1) 1delta(1) configuration. Copyright 2000 Academic Press.

Extramitochondrial localization of mortalin/mthsp70/PBP74/GRP75

Subcellular fractionation and immunofluorescence microscopy were used to identify the specific sites of intracellular residence of mortalin, also called a mitochondrial homologue of the hsp70 family, in immortal human cell lines previously assigned to four distinct complementation groups (A-D) for indefinite cell division. In addition to the mitochondria it was seen in the endoplasmic reticulum (ER) fractions of all the cell lines analyzed. Interestingly, three of the group A cells lines (EJ, GM639, and HT1080), in addition to the mitochondria and ER, exhibited cytosolically (extra-organelle) localized pool of mortalin. These findings demonstrate that mortalin is not present exclusively in mitochondria. Its residence in different organelles may be the basis of differential distribution observed previously in different human cell lines.

Optical image encryption based on multifractional Fourier transforms

We propose a new image encryption algorithm based on a generalized fractional Fourier transform, to which we refer as a multifractional Fourier transform. We encrypt the input image simply by performing the multifractional Fourier transform with two keys. Numerical simulation results are given to verify the algorithm, and an optical implementation setup is also suggested.

Genetic approaches to the study of replicative senescence

Genetic analyses of replicative senescence have revealed the dominance of the senescent phenotype since whole cell fusion of normal with immortal cells yields hybrids having limited division potential. We exploited the recessive nature of immortality by fusing different immortal human cell lines with each other and identified four complementation groups for indefinite division. This allowed for a focussed approach involving microcell mediated chromosome transfer that led to the implication of chromosomes 1, 4 and 7 as loci for cell senescence genes. More recently we have cloned the gene on chromosome 4, MORF 4. It is a member of a family of genes with motifs suggestive of transcriptional regulators. Characterization of this novel gene family should lend further insights into the phenomenon of replicative cell senescence.

Near-Infrared Laser Spectroscopy of the C(3)Delta-X(3)Delta Transition of TiS

The (0, 0), (1, 0), (2, 0), (3, 0), and (4, 0) bands of the C(3)Delta-X(3)Delta transition of TiS, between 743-863 nm, were studied using the technique of laser vaporization/reaction with supersonic cooling and laser-induced fluorescence (LIF) spectroscopy. The linewidth of the LIF spectrum obtained was about 250 MHz. The P, Q, and R branches of each DeltaOmega = 0 subband were observed. A merged least-squares fit of the measured line positions yielded molecular parameters of the v = 0-4 levels of the C(3)Delta state and the v = 0 level of the X(3)Delta state. Copyright 1999 Academic Press.

Identification of a gene that reverses the immortal phenotype of a subset of cells and is a member of a novel family of transcription factor-like genes

Based on the dominance of cellular senescence over immortality, immortal human cell lines have been assigned to four complementation groups for indefinite division. Human chromosomes carrying senescence genes have been identified, including chromosome 4. We report the cloning and identification of a gene, mortality factor 4 (MORF 4), which induces a senescent-like phenotype in immortal cell lines assigned to complementation group B with concomitant changes in two markers for senescence. MORF 4 is a member of a novel family of genes with transcription factor-like motifs. We present here the sequences of the seven family members, their chromosomal locations, and a partial characterization of the three members that are expressed. Elucidation of the mechanism of action of these genes should enhance our understanding of growth regulation and cellular aging.

[Changes of proto-oncogene expression and cytosolic free calcium in activited T-lymphocytes of aged mice]

Dot blot showed that the expression of proto-oncogene c-fos was inhibited in lymphocytes from old mice (20-24 months). In order to measure the effect of aging on signal transduction, we separated T cells by passage of spleen lymphocytes through long nylon fiber columns. Con A-induced [3H] TdR incorperation in cells from old mice was lower than that from young mice (2 months). The maximum level of [3H]TdR incorperation of old mouse T cells was only 22% of that of young mouse T cells. When T cells were stimulated with the combination of a phorber ester (PMA) and a calcium ionophore (ionomycin), [3H]TdR incorperation remained depressed in old mouse T cells. Further, cytosolic free calcium level was measured by monitoring fluoresence intensity in fura-2/AM loaded T cells. At 10 minutes after con A stimulation, the concentration of cytosolic free calcium ([Ca2+]) in old mouse T cells elevated to 273 x 10(-9)mol/L, while [Ca2+] in young mouse T cells markedly increased to 637 x 10(-9)mol/L. When T cells were stimulated with the combination of PMA and ionomycin, at 7 minutes, [Ca2+] in old mouse T cells elevated to 790 x 10(-9)mol/L, while [Ca2+] in young mouse T cells markedly increased up to 2190 x 10(-9)mol/L.