Development of Species-Specific Primers for Agronomical Thrips and Multiplex Assay for Quarantine Identification of Western Flower Thrips

While morphological identification of thrips species has been difficult because of their minute size and a lack of easily recognizable characteristics, molecular identification based on the development of specific molecular markers can be easily and reliably carried out. Among the known molecular markers, the nuclear internal transcribed spacer (ITS) exhibits distinguishable variations among thrips species. In this study, sequences of ITS2 region of 10 agriculturally important thrips were established to design species-specific primers for polymerase chain reaction (PCR). ITS2 sequence variations within these species were far less than those among species, indicating the suitability of this marker for species-specific primers design. These primers, though with one or two sporadically variable positions, showed a good efficacy within species. The specificity of these primers, examined on thrips species belonging to 15 genera, proved satisfactory. Furthermore, a multiplex PCR was used successfully for identifying Frankliniella occidentalis (Pergande), an insect pest monitored for quarantine purpose, and three additional thrips also commonly found in imported agricultural products and field samples, i.e., Thrips tabaci Lindeman, Thrips hawaiiensis (Morgan), and Frankliniella intonsa (Trybom). This study has demonstrated that specific primers and multiplex PCR based on ITS2 are reliable, convenient, and diagnostic tool to discriminate thrips species of quarantine and agricultural importance.

Accelerated healing by composites containing herb epimedium for osteoinductive regeneration

Porous composites composed of hydroxyapatite (HA), herb epimedium (EP), and chitosan (CS) were used to improve the repair of rabbit bone defects. The in vivo implantation of the HA/CS-EP showed that homogeneous bone formation occurred after 12 weeks' implantation and possessed good osteogenesis. The osteogenic process of the HA/CS-EP group was different from that of the HA/CS group. Direct bone formation of osteoblasts with HA/CS-EP as the matrix could be observed. Compared with the group filled with HA/CS, the group filled with HA/CS-EP showed significant increases in the number of osteoblasts and the bone formation area, and the areas of new bone formation in the HA/CS-EP group after 4 or 12 weeks' implantation reached 33% and 87%, respectively. The novel repair system of HA/CS-EP can induce bone formation, increase osteoblast quantity and improve osteogenesis, for EP can significantly promote the proliferation and activity of osteoblasts in the early stage and accelerate bone remodeling in the later stage. Composites containing EP could be a promising material with multifunctions of osteoinduction, osteoconduction and medication for bone repair, and herb medicine EP could be used as an osteoinduction material for bone tissue engineering.

Initial stage of growth of single-walled carbon nanotubes: modeling and simulations

Because there are different pathways to grow carbon nanotubes (CNTs), a common mechanism for the synthesis of CNTs does not likely exist. However, after carbon atoms are liberated from carbon-containing precursors by catalysts or from pure carbon systems, a common feature, the nucleation of CNTs by electron mediation, does appear. We studied this feature using the initial stage of growth of single wall CNTs (SWCNTs) by transition metal nano-particle catalysts as the working example. To circumvent the bottleneck due to the size and simulation time, we used a model in which the metal droplet is represented by a jellium, and the effect of collisions between the carbon atoms and atoms of the catalyst is captured by charge transfers between the jellium and the carbon. The simulations were performed using a transferable semi-empirical Hamiltonian to model the interactions between carbon atoms in jellium. We annealed different initial configurations of carbon clusters in jellium as well as in a vacuum. We found that in jellium, elongated open tubular structures, precursors to the growth of SWCNTs, are formed. Our model was also shown to be capable of mimicking the continued growth when more atoms were placed near the open end of the tubular structure.

[Anti-virus research of triterpenoids in licorice]

Licorice is a leguminous plant of glycyrrhiza. It is a traditional Chinese herbal medicine. Triterpenoid is one of the mainly active components of licorice. In recent years, the broad-spectrum antiviral activity of many triterpenoids in licorice was confirmed, and these findings have become a hot spot of antiviral immunity. The triterpenoids of licorice has the potential to become a novel broad-spectrum antiviral medicine and will be widely used in the clinical treatment. This review provided a summary of the recent anti-virus research progress on several triterpenoids in licorice, such as glycyrrhizic acid, glycyrrhizin, glycyrrhetinic acid and its derivatives. The antiviral roles of triterpenoids in licorice against herpes virus, HIV, hepatitis virus, SARS coronavirus and influenza virus were briefly summarized.

BRAF mutation is associated with the unique morphology of traditional serrated adenoma of the colorectum

Traditional serrated adenoma (TSA) consists of glands with tall cells and short cells. Two kinds of cells alternate to give a unique serrated configuration. The aim of this study was to identify the relationship between the alterations of both Wnt and serrated pathways and the unique morphology of TSAs. The tall and short cells in 28 TSAs were separated by microdissection. Semi-nested polymerase chain reaction was performed to detect the mutations of BRAF, β-catenin, APC, and KRAS. BRAF mutations were observed in 22 of 28 (78.6%) TSAs, and all mutations occurred at the tall cells. In conclusion, BRAF mutation is associated with the serrated morphology of TSAs. Genetic alterations in both the serrated pathway and the Wnt signaling pathway may both contribute to TSAs.

Subtalar distraction osteogenesis for posttraumatic arthritis following intra-articular calcaneal fractures

BACKGROUND

The most common treatment for old calcaneal fractures accompanied by subtalar joint injury is the use of subtalar in situ arthrodesis and subtalar distraction bone-block arthrodesis or osteotomy. This article describes the introduction of a novel surgical treatment, gradual subtalar distraction with external fixation and restoration of the calcaneal height, and presents an assessment of its efficacy.

METHODS

The protruding lateral calcaneus and the articular surfaces and subchondral bone of the posterior facet of the subtalar joint were surgically removed. An external fixator, attached with 2 pins in the subcutaneous tibia and 2 pins in the posterolateral calcaneus, was used to fix the subtalar joint for 7 to 10 days followed by gradual subtalar distraction at 1 mm/d. The lengthening procedure was stopped when the calcaneal height was restored according to radiography. The external fixator was removed after bone fusion. Seven cases of old calcaneal fractures accompanied by severe subtalar joint injury (8 feet) were treated using this method. Average follow-up was 14.3 months (range, 7-36 months).

RESULTS

In all 7 cases (1 case of both feet), the postoperative wound healed primarily. The calcaneal heights of all 8 feet were partially restored. Subtalar joint bone fusion was completed within 4 to 6 months after the operation. The average preoperative American Orthopedic Foot & Ankle Society (AOFAS) hindfoot score was 25.3, and the average postoperative AOFAS score was 76.3.

CONCLUSION

Subtalar distraction osteogenesis with external fixation was a novel and effective method for the treatment of old calcaneal fractures accompanied by severe subtalar joint injury in this small group of patients.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

[Induction of VEGF in human monocytes by DENV infection and the regulatory mechanism]

To investigate the effects of DENV infection on the expression of Vascular endothelial growth factor (VEGF) in monocytes, and to explore which innate immune signaling pathway is responsible for VEGF induction. Real-time PCR was used to determine the expression levels of VEGF in DENV-infected THP-1. We found that different serotype viruses (DENV1, DENV2, DENV3) induced the VEGF expression. Moreover, VEGF expression was significantly increased in human primary monocytes infected with DENV 2. In addition, VEGF induction by DENV2 was significantly impaired by knockdown of TLR3 and interferon-beta promoter stimulator 1 (IPS-1), or by inhibition of ERK, JNK or NF-kappaB. These results demonstrated that DENV induced VEGF expression in monocytes, and the activation of TLR3, IPS-1 signal pathways were required for DENV2-triggered VEGF induction, suggesting that VEGF might be a promising therapeutic target for DHF.

Green tea (Camelia sinensis) mediated suppression of IgE production by peripheral blood mononuclear cells of allergic asthmatic humans

Recent studies in our laboratory demonstrated the suppression of immunoglobulin E (IgE) production by green tea extract (GTE) in U266 cells. However, the effects of GTE or one of its components (EGCG) on IgE production by human peripheral blood mononuclear cells (PBMC) are unknown. PBMC (1.5 × 10⁶) obtained from serum IgE+, allergic asthmatic patients, were cultured ± GTE (1-100 ng/ml) or purified EGCG (0.5-50 ng/ml), and IgE levels were determined on day 10 by enzyme-linked immunosorbent assay (ELISA). High levels of IgE were detected in supernatants of the PBMC cultures on day 10. When GTE was included in vitro, IgE production by PBMC was suppressed on day 10, compared with control. Purified EGCG included in vitro also suppressed IgE production, but at lower levels, compared with control. This study demonstrates that GTE and its major catechin, EGCG, have immunoregulatory effects on human IgE responses.

Overexpression of the cytochrome P450 monooxygenase (cyp71av1) and cytochrome P450 reductase (cpr) genes increased artemisinin content in Artemisia annua (Asteraceae)

Finding an efficient and affordable treatment against malaria is still a challenge for medicine. Artemisinin is an effective anti-malarial drug isolated from Artemisia annua. However, the artemisinin content of A. annua is very low. We used transgenic technology to increase the artemisinin content of A. annua by overexpressing cytochrome P450 monooxygenase (cyp71av1) and cytochrome P450 reductase (cpr) genes. CYP71AV1 is a key enzyme in the artemisinin biosynthesis pathway, while CPR is a redox partner for CYP71AV1. Eight independent transgenic A. annua plants were obtained through Agrobacterium tumefaciens-mediated transformation, which was confirmed by PCR and Southern blot analyses. The real-time qPCR results showed that the gene cyp71av1 was highly expressed at the transcriptional level in the transgenic A. annua plants. HPLC analysis showed that the artemisinin content was increased in a number of the transgenic plants, in which both cyp71av1 and cpr were overexpressed. In one of the transgenic A. annua plants, the artemisinin content was 38% higher than in the non-transgenic plants. We conclude that overexpressing key enzymes of the biosynthesis pathway is an effective means for increasing artemisinin content in plants.

Theoretical predictions of a bucky-diamond SiC cluster

A study of structural relaxations of Si(n)C(m) clusters corresponding to different compositions, different relative arrangements of Si/C atoms, and different types of initial structure, reveals that the Si(n)C(m) bucky-diamond structure can be obtained for an initial network structure constructed from a truncated bulk 3C-SiC for a magic composition corresponding to n = 68 and m = 79. This study was performed using a semi-empirical Hamiltonian (SCED-LCAO) since it allowed an extensive search of different types of initial structures. However, the bucky-diamond structure predicted by this method was also confirmed by a more accurate density functional theory (DFT) based method. The bucky-diamond structure exhibited by a SiC-based system represents an interesting paradigm where a Si atom can form three-coordinated as well as four-coordinated networks with carbon atoms and vice versa and with both types of network co-existing in the same structure. Specifically, the bucky-diamond structure of the Si(68)C(79) cluster consists of a 35-atom diamond-like inner core (four-atom coordinations) suspended inside a 112-atom fullerene-like shell (three-atom coordinations).

Phase sensitive SPR sensor for wide dynamic range detection

Phase detection has been utilized to enhance the sensitivity of surface plasmon resonance (SPR) sensors for a long time. However, an inherent drawback for phase sensitive SPR sensors are their limited dynamic range, which has greatly hindered wide applications of such sensors. In this Letter, a design combining phase detection and angular interrogation has been proposed to provide an SPR sensor with both high sensitivity and wide dynamic range. As a result, a resolution of 2.2×10^-7 RIU with a dynamic range of over 0.06 RIU has been achieved simultaneously. An added advantage of this design is the flexibility for sensitivity and dynamic range adjustment.

The pesticide deltamethrin increases free radical production and promotes nuclear translocation of the stress response transcription factor Nrf2 in rat brain

The transcription factor NF-E2-related factor 2 (Nrf2) plays a critical role in the mammalian response to chemical and oxidative stress through induction of phase II detoxification enzymes and oxidative stress response proteins. We reported that Nrf2 expression was activated by deltamethrin (DM), a prototype of the widely used Parathyroid pesticides, in PC12 cells. However, no study has examined Nrf2 nuclear translocation and free radical production, two hallmarks of oxidative stress, in the mammalian brain in vivo. To this end, we examined translocation of Nrf2 and production of free radicals in rat brain exposed to DM. Indeed, DM initiated nuclear translocation of Nrf2 in a dose-dependent manner. Furthermore, Nrf2 translocation was accompanied by the expression of heme oxygenase-1 gene, an Nrf2-regulated gene linked to free radical production. Deltamethrin exposure promoted free radical formation in rat brain and reactive oxygen species generation in PC12 cells. Translocation of Nrf2 may be a response to DM-dependent induction of free radicals and DM may act as a mammalian neurotoxin by initiating oxidative stress.

Systemic delivery of E6/7 siRNA using novel lipidic particles and its application with cisplatin in cervical cancer mouse models

Small interfering RNA (siRNA) shows great promise in cancer therapy, but its effectiveness in vivo still remains a crucial issue for its transition into the clinics. Although the successful use of polyethylene glycol (PEG)ylated lipidic delivery systems have already been reported, most of the formulation procedures used are labour intensive and also result in unstable end products. We have previously developed a simple yet efficient hydration-of-freeze-dried-matrix (HFDM) method to entrap siRNA within lipid particles, in which the products exhibited superior stability. Here, we show that these HFDM-formulated particles are stable in the presence of serum and can deliver siRNA efficiently to tumours after intravenous administration. Using these particles, around 50% knockdown of the target gene expression was observed in tumours. With the use of siRNA targeting the E6/7 oncogenes expressed in cervical cancer, we showed a 50% reduction in tumour size. This level of tumour growth suppression was comparable to that achieved from cisplatin at the clinically used dose. Overall, our results demonstrate the feasibility of using HFDM-formulated particles to systematically administer E6/7-targeted siRNA for cervical cancer treatment. The simplicity of preparation procedure along with superior product stability obtained from our method offers an innovative approach for the in vivo delivery of siRNA.

Spin-phonon coupling effects in antiferromagnetic Cr2O3 nanoparticles

In the present work we use Raman microscopy to investigate the size effect of spin-phonon coupling in antiferromagnetic Cr2O3 nanoparticles. The peculiarities of the dependency of the phonon wave number on temperature (with a relatively weak peak at 293 cm(-1)) can be attributed to the spin-phonon coupling. The variation with temperature of the spin-phonon mode develops when the antiferromagnetic state is near the ordering temperature of the Cr spins. The observations can be reasonably well interpreted by describing the order parameter. A shift in frequency is caused by a strong spin-phonon interaction in Cr2O3. The obtained s-ph coefficients are found to be consistent with the strain, where raising the strain results in weakening of the s-ph coupling.

Size-effect induced short-range magnetic ordering in germanium nanostructures

Formation of ordered magnetic states in germanium nanostructures embedded in SiO2 has been investigated. Samples with the nanostructures were prepared by sputtering deposition on Si(100) substrates, followed by thermal annealing in vacuum. Transmission electron microscopy, energy dispersive X-ray spectrometry, and Raman spectroscopy have been used to characterize the samples. Magnetic measurements were performed using a superconducting quantum interference device. Size-effect induced magnetic orderings in the germanium nanostructures were found to be present at room temperatures and below. Superparamagnetic behavior was observed at temperatures above 230 K, whereas thermal excitation of spin reorientation and magnetic coupling has been revealed at temperatures below 60 K. Inverted hysteresis loops with negative remanences and multiple plateaus revealed the ferri- or antiferromagnetic nature of the coupling. Inter-domain coupling and effect of magnetic anisotropy will be discussed based on the experimental results and simulations with a spin reorientation model.

Meconium aspiration syndrome: experiences in Taiwan

Meconium aspiration syndrome (MAS) is still one of the most challenged diseases for the neonatologists. We reviewed our earlier studies of MAS in an attempt to provide some idea for more understanding of MAS. This study is a retrospective review and summarization of our earlier studies in MAS at two tertiary neonatal centers in Taiwan. Incidence of MAS was decreased sharply in Taiwan. MAS infants who required resuscitation in the birth room being out-born, birth asphyxia and infants who developed persistent pulmonary hypertension (PPHN) and pneumothrax were associated with increasing mortality. In MAS infants who neither required mechanical ventilation nor had a history suggestive of perinatal infection, antibiotic treatments would not affect the outcome of MAS. Dexamethasone did reduce inflammation response and improve cardiopulmonary perfusion. However, steroids did not prevent the development of PPHN. Our review provided the risk factors of mortality for MAS. Antibiotic treatments should not be a routine for every infant with MAS. Although steroids reduce pulmonary inflammation, their role in the prevention of PPHN remains to be further studied.

YC-1 induces apoptosis of human renal carcinoma A498 cells in vitro and in vivo through activation of the JNK pathway

BACKGROUND AND PURPOSE

The aim of this study was to elucidate the mechanism of YC-1{3-(5'-hydroxy methyl-2'-furyl)-1-benzylindazole}-induced human renal carcinoma cells apoptosis and to evaluate the potency of YC-1 in models of tumour growth in mice.

EXPERIMENTAL APPROACH

YC-1-mediated apoptosis was assessed by analysis of MTT, SRB, DAPI staining and flow cytometry analysis. Knockdown of JNK protein was achieved by transient transfection using siRNA. The mechanisms of action of YC-1 on different signalling pathways involved were studied using western blot. Fas clustering was analysed by confocal microscopy and in vivo efficacy was examined in a A498 xenograft model.

KEY RESULTS

YC-1 displayed cytotoxicity in renal carcinoma cells at 10(-7)-10(-8) M. Increased condensation of chromatin was observed and an increase in the cell population in subG1 phase. Moreover, YC-1 triggered mitochondria-mediated and caspase-dependent pathways. YC-1 significantly induced Fas ligand expression, but did not modify either the protein levels of death receptors or ligands. In addition, Fas clustering in cells responsive to YC-1 was observed, suggesting involvement of a Fas-mediated pathway. Furthermore, YC-1 markedly induced phosphorylation of JNK and a JNK inhibitor, SP600125, and siRNA JNK1/2 significantly reversed YC-1-induced cytotoxicity and protein expression. We suggest that YC-1 induced JNK phosphorylation, the upregulation of FasL and Fas receptor clustering to promote the activation of caspases 8 and 3, resulting in apoptosis. Finally, we demonstrated the antitumour effect of YC-1 in vivo.

CONCLUSIONS AND IMPLICATIONS

These data suggest that YC-1 is a good candidate for development as an anticancer drug.

Incident open-angle glaucoma and intraocular pressure

PURPOSE

To evaluate the role of baseline intraocular pressure (b-IOP) as a risk factor for incident open-angle glaucoma (OAG) in participants of African origin from the Barbados Eye Studies.

DESIGN

Population-based 9-year cohort study.

PARTICIPANTS

Three thousand two hundred twenty-two persons examined during the study period who were free of glaucoma at baseline and at risk of developing OAG during the 9-year follow-up.

METHODS

Study protocols were standardized and included ophthalmic and other measurements, automated perimetry, applanation tonometry, fundus photography, and comprehensive ophthalmologic examination for those referred. The product-limit approach was used to estimate incidence. Relationships between b-IOP and incidence were evaluated by adjusted relative risk ratios (RRs) with 95% confidence intervals (CIs), based on Cox regression models.

MAIN OUTCOME MEASURE

The 9-year incidence of OAG was based on both visual field and optic disc abnormalities, with ophthalmologic evaluations to exclude other possible causes.

RESULTS

The overall 9-year incidence of OAG was 4.4% (95% CI, 3.7%-5.2%), and the mean (standard deviation) b-IOP among persons at risk was 18.0 mmHg (4.1). Among the 125 incident OAG cases, the mean b-IOP was 21.9 mmHg and 46% had b-IOP of >21 mmHg. In contrast, the nonincident group had a mean b-IOP of 17.8 mmHg and only 12% had b-IOP of >21 mmHg. Overall, OAG risk increased by 12% with each 1-mmHg increase in IOP (RR, 1.12; 95% CI, 1.08-1.16). Incidence steadily increased from 1.8% (95% CI, 1.2%-2.7%) for persons with b-IOP of < or =17 mmHg (referent group) to 22.3% (95% CI, 15.8%-31.1%) for those with b-IOP > 25 mmHg, resulting in an adjusted RR of 13.1 (95% CI, 7.1-24.1) among the latter group. The attributable risk for IOP of >25 mmHg was 19%. Using 21 mmHg as a cutoff, the RR was 7.9 (95% CI, 3.8-16.2) and the attributable risk was 37%.

CONCLUSIONS

After 9 years' follow-up, the risk of OAG was positively related to IOP levels at baseline. Although persons with b-IOP of >25 mmHg had a 13-fold RR of developing OAG, most cases arose with lower b-IOP. This study thus confirms the role of IOP as an influential risk factor, yet at the same time underscores its limitations in predicting OAG.

Nine-Year Incidence of Open-Angle Glaucoma in the Barbados Eye Studies

PURPOSE

To determine the 9-year incidence of open-angle glaucoma (OAG) in African-descent participants of the Barbados Eye Studies.

DESIGN

Nine-year cohort study with 81% to 85% participation.

PARTICIPANTS

Three thousand two hundred twenty-two persons without definite OAG at baseline, at risk of developing OAG at follow-up.

METHODS

The standardized protocol included automated perimetry and various ophthalmic measurements, with a comprehensive ophthalmologic examination for those referred. Fundus photographs were evaluated independently by masked graders. Incidence was estimated by the product-limit approach. Relative risk (RR) ratios with 95% confidence intervals (CIs) were based on Cox regression models with discrete time.

MAIN OUTCOME MEASURE

Nine-year incidence of definite OAG, based on the development of visual field defects and glaucomatous optic neuropathy, with ophthalmologic confirmation.

RESULTS

The 9-year incidence of definite OAG was 4.4% (95% CI, 3.7%-5.2%), or an average of 0.5%/year, based on 125 new cases. Incidence increased greatly with age, from 2.2% at ages 40 to 49 years to 7.9% at ages 70 years or older, and tended to be higher in men than women (4.9% vs. 4.1%; RR, 1.3; 95% CI, 0.9-1.8). More than half (53%) of new cases were undetected, and of these, one third had intraocular pressure of 21 mmHg or less. When 141 persons developing suspected/probable OAG were considered, the total incidence was 9.4% (8.4%-10.6%), averaging approximately 1%/year, also increasing with age, and significantly higher in men than women (10.7% vs. 8.6%; RR, 1.31; 95% CI, 1.02-1.67).

CONCLUSIONS

These new data provide a measure of the long-term risk of OAG in an African-descent population, which is markedly higher than in persons of European ancestry. Results confirm the increased risk with age and in men. The incidence data fill a gap in our understanding of OAG risk and have implications for public health policy and planning; they also will allow the study of factors related to the risk of OAG development.

Managerial attitudes on the development of health promoting hospitals in Beijing

In 2002, the Beijing Committee for Disease Prevention launched guidelines based on the Ottawa Charter for Health Promotion on health promoting hospitals (HPHs). HPH pilot projects were then initiated, on a voluntary basis, in 44 Beijing hospitals. Evaluations have been undertaken to assess the impacts of the pilot project. This article outlines this HPH project, its development and evaluation and reports on the attitudes and contribution of hospital management as determined by questionnaires and interviews from 281 managerial employees from 106 Beijing hospitals (93 from pilot hospitals and 188 from control). The results of the evaluation indicate that long-term health promotion planning and health promotion specialized funds have been better established in pilot hospitals than in the control group and also that the concept of HPH is better understood by managerial staff in pilot hospitals than by those in control hospitals. The main perceived barriers faced in the development of HPH are shortages of funds, personnel, time management and professional skills. To further develop HPHs in China, effort needs to be made to ensure that hospital leaders and management are considered first. If managerial staff have an appropriate understanding of the concept and principles of HPH, then it is more likely that health promotion activities can be introduced into the daily workings of hospitals, and the necessary funds, personnel and training on health promotion skills be provided.

Two-dimensional biosensor arrays based on surface plasmon resonance phase imaging

We present a biosensor design based on capturing the two-dimensional (2D) phase image of surface plasmon resonance (SPR). This 2D SPR imaging technique may enable parallel label-free detection of multiple analytes and is compatible with the microarray chip platform. This system uses our previously reported differential phase measurement approach, in which 2D phase maps obtained from the signal (P) and reference (S) polarizations are compared pixel by pixel. This technique greatly improves detection resolution as the subtraction step can eliminate measurement fluctuations caused by external disturbances as they essentially appear in both channels. Unlike conventional angular SPR systems, in which illumination from a range of angles must be used, phase measurement requires illumination from only one angle, thus making it well suited for 2D measurement. Also, phase-stepping introduced from a moving mirror provides the necessary modulation for accurate detection of the phase. In light of the rapidly increasing need for fast real-time detection, quantification, and identification of a range of proteins for various biomedical applications, our 2D SPR phase imaging technique should hold a promising future in the medical device market.

A high yield robotic synthesis of 9-(4-[18F]-fluoro-3-hydroxymethylbutyl)guanine ([18F]FHBG) and 9-[3-[18F]fluoro-1-hydroxy-2-propoxy)methyl]guanine([18F] FHPG) for gene expression imaging

The aim of this study was to develop an automated synthesis of 9-(4-[(18)F]-fluoro-3-hydroxymethylbutyl)guanine ([(18)F]FHBG) and 9-[(3-[(18)F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([(18)F]FHPG) using a Scanditronix Anatech RB III robotic system. [(18)F]HF was produced via (18)O(p, n)(18)F using a Scanditronix MC17F cyclotron. On average, a typical run produced [(18)F]FHBG and [(18)F]FHPG with an uncorrected radiochemical yield of 19% and 16%, respectively, at end of synthesis (EOS) from irradiation of 95% enriched [(18)O]water. The total synthesis time was 80 min. The retention time of [(18)F]FHBG and [(18)F]FHPG (the radio-peak) was 3.9 and 4.0 min, respectively, which was consistent with the [(19)F]FHBG and [(19)F]FHPG ultraviolet peak. The radiochemical purity was greater than 97%. A robotic, automated method for [(18)F]FHBG and [(18)F]FHPG radiosynthesis is therefore feasible. The radiation burden for the operator can be reduced as much as possible. Sufficient radioactivities of [(18)F]FHBG and [(18)F]FHPG could be obtained for non-invasive monitoring the expression of transfected gene in vivo with positron emission tomography (PET).

Application of two-dimensional spectral surface plasmon resonance to imaging of pressure distribution in elastohydrodynamic lubricant films

What we believe to be a novel two-dimensional spectral surface plasmon resonance imaging technique determining pressure distribution in elastohydrodynamic lubricant films is presented. This technique makes use of the spectral characteristics associated with the surface plasmon resonance (SPR) effect, and it provides more spectral information in refractive index mapping than conventional contrast SPR imaging. Two-dimensional imaging is demonstrated and applied to a highly pressurized liquid lubricant trapped inside an elastohydrodynamic lubrication (EHL) dimple. The hydrostatic pressure inside the EHL dimple causes a localized change of the refractive index of the lubrication oil. This also results in a shift in the spectral SPR absorption dip. By monitoring the color changes within the SPR image and calibrating with lubricants of known refractive index profiles, we can obtain a direct measurement of the refractive index distribution within the EHL dimple. PB 2400 lubricant dimples were studied in our experiments. The proposed SPR imaging approach is irrespective of the absolute lubricant film thickness h, therefore overcoming the major limitations of a conventional optical interference technique. With further development of the two-dimensional refractive index mapping technique, widespread applications in various fields are possible, including high-throughput sensors and the detection of bioaffinity interactions.

Thallium-201 scan in evaluating thyroid nodules following equivocal fine-needle aspiration cytology

The AIM of this prospective study was to evaluate the usefulness of the thallium-201 ( (201) Tl) thyroid scan in the detection of malignancy in cold thyroid nodules whose status was equivocal following palpation fine-needle aspiration cytology (FNAC).

PATIENTS, METHODS

Fifty-one patients with clinically palpable solitary cold thyroid nodules classified as non-diagnostic or suspicious following biopsy underwent (201) Tl thyroid scans. Each scan was performed 15 min (early scan) and 3 h (delayed scan) after an intravenous administration of 74 MBq (201) Tl. Thallium uptake in the nodules was visually assessed and scored on a three point scale, with a grade of three defining malignancy. All patients underwent surgery and the histopathology of nodule tissues were compared with results of the scans.

RESULTS

Fifty-one nodules were examined. Forty were benign and 11 were malignant. For early scans, the diagnostically relevant parameters were: sensitivity (100%), specificity (75%), and accuracy (80%). Corresponding findings for the delayed scan were: 91%, 98%, and 96%.

CONCLUSION

The (201) Tl scan is useful for detecting malignancy in cold thyroid nodules classified as nondiagnostic or suspicious lesions by FNAC.