Validation of the Efficacy of Ultrasound Speckle Tracking in Measuring Tendon Gliding After Finger Flexor Tendon Repair

OBJECTIVE

Restricted tendon gliding is commonly observed in patients after finger flexor tendon (FFT) repair. The study described here was aimed at quantifying the amount of FFT gliding to evaluate the recovery of post-operative tendons using a 2-D radiofrequency (RF)-based ultrasound speckle tracking algorithm (UST).

METHODS

Ex vivo uniaxial tensile testing of porcine flexor tendons and in vivo isometric testing of human FFT were implemented to verify the efficacy of UST beforehand. The verified UST was then applied to the patients after FFT repair to compare tendon gliding between affected and healthy sides and to investigate its correlation with the joint range of motion (ROM).

RESULTS

Excellent validity was confirmed with the average R2 value of 0.98, mean absolute error of 0.15 ± 0.08 mm and mean absolute percentage error of 5.19 ± 2.43% between results from UST and ex vivo testing. The test-retest reliability was verified with good agreement of ICC (0.90). The affected side exhibited less gliding (p = 0.001) and smaller active ROM (p = 0.002) than the healthy side. Meanwhile, a significant correlation between tendon gliding and passive ROM was found only on the healthy side (ρ = 0.711, p = 0.009).

CONCLUSION

The present study provides a promising protocol to evaluate post-operative tendon recovery by quantifying the amount of FFT gliding with a validated UST. FFT gliding in patients with different levels of ROM restriction should be further explored for categorizing the severity of tendon adhesion.

Controlled Growth of Highly Oriented Perovskite Crystals in Polymer Solutions via Selective Solvent Vapor Diffusion

Organic-inorganic hybrid perovskites have garnered significant attention in optoelectronics owing to their outstanding tunable optical characteristics. Controlled growth of perovskite nanocrystals from solutions is key for controlling the emission intensity and photoluminescence lifetime of perovskites. In particular, most studies have focused on controlling the crystallization of perovskite through chemical treatment using chelating ligands or physical treatment via antisolvent diffusion, and there exists a trade-off between the photoluminescence intensity and lifetime of perovskites. Herein, a selective solvent vapor-assisted crystallization with the aid of a functional polymer, which nanoscale perovskite crystals are grown andante from precursor solution, is presented for tuning the crystallization and optical properties of a common halide perovskite, methylammonium lead bromide (MAPbBr3 ). The proposed method here produces perovskite nanocrystals in the range of 200-300 nm. The spin-coated thin film formed from the perovskite solution exhibits strong green photoluminescence with a long lifetime. The effects of the functional group and polymer dosage on the crystallization of MAPbBr3 are systematically investigated, and the crystallization mechanism is explained based on a modified LaMer model. This study provides an advanced solution process for precisely controlling perovskite crystallization to enhance their optical properties for next-generation optoelectronic devices.

Sustained Flexible Photonic Transistor Memories Based on Fully Natural Floating Gate Electrets

Photonic transistor memory with high-speed communication and energy-saving capabilities has emerged as a new data storage technology. However, most floating-gate electrets are composed of quantum dots derived from petroleum or metals, which are either toxic or harmful to the environment. In this study, an environmentally friendly floating-gate electret made entirely from biomass-derived materials was designed for photonic memories. The results show that the photosensitive hemin and its derivative protoporphyrin IX (PPIX) were successfully embedded in a polylactic acid (PLA) matrix. Correspondingly, their disparate photochemistry and core structure strongly affected the photosensitivity and charge-trapping capacity of the prepared electrets. With an appropriate energy-level alignment, the interlayer exciton formed with the correct alignment of energy levels within the PPIX/PLA electret. In addition, the demetallized core offered a unique relaxation dynamic and additional trapping sites to consolidate the charges. Correspondingly, the as-prepared device exhibited a memory ratio of up to 2.5 × 10⁷ with photo-writing-electrical-erasing characteristics. Conversely, hemin demonstrated self-charge transfer during relaxation, making it challenging for the device to store the charges and exhibit a photorecovery behavior. Furthermore, the effect of trapping site discreteness on memory performance was also investigated. The photoactive components were effectively distributed due to the high dipole-dipole interaction between the PLA matrix and PPIX, resulting in a sustained memory performance for at least 10⁴ s after light removal. The photonic memory was also realized on a bio-derived dielectric flexible substrate. Accordingly, a reliable photorecording behavior was observed, wherein, even after 1000 cycles of bending under a 5 mm bending radius, the data was retained for more than 10⁴ s. To our knowledge, it is the first time that a two-pronged approach has been used to improve the performance of photonic memories while addressing the issue of sustainability with a biodegradable electret made entirely from natural materials.

Diagnostic accuracy of algorithms to define incident and second hip fractures: A Taiwan validation study

BACKGROUND

Previous epidemiological researchers have used various algorithms to identify a second hip fracture; however, there has been no validation of these algorithms to date. This study aimed to verify existing algorithms for identifying second hip fracture under the International Classification of Diseases diagnostic coding systems. Furthermore, we examined the validity of two newly proposed algorithms that integrated the concept of periprosthetic fractures and laterality of the ICD-10 coding system.

METHODS

Claims data of patients hospitalized for hip fracture from National Taiwan University Hospitals between 2007 and 2020 were retrieved. Hip fracture was confirmed by 2 orthopaedic surgeons with medical records and imaging data as gold standards. The validity of 9 existing and 2 newly proposed algorithms for identifying second hip fracture was evaluated.

RESULTS

The positive predictive value (PPV) range between 84% and 90% in existing algorithms for identifying second hip fractures. Noteworthy, the longer time interval for discrimination resulted in slightly increased PPV (from 87% to 90%), while decreased sensitivity noticeably (from 87% to 72%). When considering the information about periprosthetic fracture, the PPV increased to 91% without diminished sensitivity. The PPV of the newly proposed ICD-10-specific algorithm was 100%.

CONCLUSION

Algorithms integrated clinical insights of periprosthetic fractures and laterality concept of ICD-10 coding system provided satisfactory validity and help precisely define second hip fracture in future database research.

Molecular template growth of organic heterojunctions to tailor visual neuroplasticity for high performance phototransistors with ultralow energy consumption

The optical and charge transport properties of organic semiconductors are strongly influenced by their morphology and molecular structures. Here we report the influence of a molecular template strategy on anisotropic control via weak epitaxial growth of a semiconducting channel for a dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT)/para-sexiphenyl (p-6P) heterojunction. The aim is to improve charge transport and trapping, to enable tailoring of visual neuroplasticity. The proposed phototransistor devices, comprising a molecular heterojunction with optimized molecular template thickness, exhibited an excellent memory ratio (I_ON/I_OFF) and retention characteristics in response to light stimulation, owing to the enhanced orientation/packing of DNTT molecules and a favorable match between the LUMO/HOMO levels of p-6P and DNTT. The best performing heterojunction exhibits visual synaptic functionalities, including an extremely high pair-pulse facilitation index of ∼206%, ultralow energy consumption of 0.54 fJ, and zero-gate operation, under ultrashort pulse light stimulation to mimic human-like sensing, computing, and memory functions. An array of heterojunction photosynapses possess a high degree of visual pattern recognition and learning, to mimic the neuroplasticity of human brain activities through a rehearsal learning process. This study provides a guide to the design of molecular heterojunctions for tailoring high-performance photonic memory and synapses for neuromorphic computing and artificial intelligence systems.

Fully Photoswitchable Phototransistor Memory Comprising Perovskite Quantum Dot-Based Hybrid Nanocomposites as a Photoresponsive Floating Gate

Tremendous research efforts have been dedicated into the field of photoresponsive nonvolatile memory devices owing to their advantages of fast transmitting speed, low latency, and power-saving property that are suitable for replacing current electrical-driven electronics. However, the reported memory devices still rely on the assistance of gate bias to program them, and a real fully photoswitchable transistor memory is still rare. Herein, we report a phototransistor memory device comprising polymer/perovskite quantum dot (QD) hybrid nanocomposites as a photoresponsive floating gate. The perovskite QDs offer an effective discreteness with an excellent photoresponse that are suitable for photogate application. In addition, a series of ultraviolet (UV)-sensitive insulating polymer hosts were designed to investigate the effect of UV light on the memory behavior. We found that a fully photoswitchable memory device was fulfilled by using the independent and sequential photoexcitation between a UV-sensitive polymer host and a visible light-sensitive QD photogates, which produced decent photoresponse, memory switchability, and highly stable memory retention with a memory ratio of 10⁴ over 10⁴ s. This study not only unraveled the mystery in the fully photoswitchable functionality of nonvolatile memory but also enlightened their potential in the next-generation electronics for light-fidelity application.

Harnessing of Spatially Confined Perovskite Nanocrystals Using Polysaccharide-based Block Copolymer Systems

Metal halide perovskite nanocrystals (PVSK NCs) are generally unstable upon their transfer from colloidal dispersions to thin film devices. This has been a major obstacle limiting their widespread application. In this study, we proposed a new approach to maintain their exceptional optoelectronic properties during this transfer by dispersing brightly emitting cesium lead halide PVSK NCs in polysaccharide-based maltoheptaose-block-polyisoprene-block-maltoheptaose (MH-b-PI-b-MH) triblock copolymer (BCP) matrices. Instantaneous crystallization of ion precursors with favorable coordination to the sugar (maltoheptaose) domains produced ordered NCs with varied nanostructures of controlled domain size (≈10-20 nm). Confining highly ordered and low dimension PVSK NCs in polysaccharide-based BCPs constituted a powerful tool to control the self-assembly of BCPs and PVSK NCs into predictable structures. Consequently, the hybrid thin films exhibited excellent durability to humidity and stretchability with a relatively high PL intensity and photoluminescence quantum yield (>70%). Furthermore, stretchable phototransistor memory devices were produced and maintained with a good memory ratio of 10⁵ and exhibited a long-term memory retention over 10⁴ s at a high strain of 100%.

Increased fracture risk after discontinuation of anti-osteoporosis medications among hip fracture patients: A population-based cohort study

BACKGROUND

To compare the risks of major osteoporotic, vertebral, and non-vertebral fractures between patients who discontinued anti-osteoporosis medications.

METHODS

We conducted a comparative effectiveness study with a nationwide population-based cohort study design. Patients aged ≥50 years admitted between 2012 and 2015 for incident hip fractures and receiving denosumab or bisphosphonates with sufficient compliance for at least 1 year were included. Patients were categorized into persistent or non-persistent denosumab or bisphosphonates users based on their subsequent use pattern. The main outcomes were subsequent hospitalizations for a major osteoporotic, vertebral or non-vertebral fracture. Multivariate, time-varying Cox proportional hazards model was used to evaluate the risk of major outcomes.

RESULTS

Compared with persistent denosumab users, non-persistent denosumab users had a significantly higher risk of major osteoporotic fractures (hazard ratio [HR] = 1.60; 95% confidence interval [CI], 1.20-2.14), vertebral fractures (HR = 2.18; 95% CI, 1.46-3.24) and death (HR = 3.57; 95%CI, 2.63-4.84). However, the increased risk of fracture was not found in both persistent and non-persistent bisphosphonates users. Noteworthy, the increased risk of vertebral fractures in non-persistent denosumab users was more pronounced within 1 year post-discontinuation (HR = 2.90; 95% CI, 1.77-4.74) and among patients who discontinued from 2-year denosumab therapy (HR = 3.58; 95% CI, 1.74-7.40).

DISCUSSION

Discontinuation of denosumab resulted in an increased risk of major osteoporotic fractures, especially vertebral fractures. The increased risk tends to reveal within 1 year post-discontinuation and be greater after a longer treatment duration. Notably, only fracture with hospitalization was identified as our research outcome, the real risk of osteoporotic fracture post discontinuation is believed to be higher, especially for vertebral fracture.

A Multi-Institutional Randomized Controlled Trial to Investigate Whether Zoledronate Prevents Bone Loss After Discontinuation of Denosumab: The Study Protocol of Denosumab Sequential Therapy (DST) Trial

Background: Though denosumab is an effective treatment for osteoporosis, the rebound effect after discontinuation has drawn investigators' attention. It includes a dramatic loss of gained bone mineral density (BMD) and an increased risk of vertebral fractures. This prospective multi-institutional randomized controlled trial aims to investigate whether zoledronate prevents loss of BMD after discontinuation of denosumab. The trial was registered as Denosumab Sequential Therapy (DST) trial in March 2019 at clinicaltrials.gov, with the identifier NCT03868033.

Methods: The study is conducted at National Taiwan University Hospital and its branches. Patients who have continuously received denosumab treatment for two or more years are surveyed for eligibility. Baseline characteristics and questionnaires of life quality are recorded after recruitment. BMD, circulating levels of bone turnover markers (BTMs), including serum N-terminal propeptide of type 1 collagen (P1NP) and C-terminal telopeptide (CTX), are checked before the stratified randomization to 4 groups. Biological sex and the T-scores are used to create 4 strata. The participants in group 1 adhere to regular denosumab therapy for another 2 years. All the other patients receive on-time zoledronate treatment in the first year. The participants in group 2, 3, and 4 have on-time denosumab, on-time zoledronate and drug holiday in the second year, respectively. BMDs are checked annually. Pre-scheduled checkpoints of BTMs are also arranged. For patient safety, rescue treatment with another injection of zoledronate will be applied to the patients on drug holiday if the CTX levels raise above the pre-specified threshold, 0.573 ng/mL for women and 0.584 ng/mL for men. The primary outcomes are the percentage changes of BMDs in lumbar spine, total hip and femoral neck. The secondary outcomes include the changes of serum level of the BTMs, new osteoporotic fractures, extra zoledronate injections needed in group 4 and the differences of quality of life.

Discussion: We aim to provide evidence whether zoledronate prevents bone loss after denosumab cessation. To our knowledge, the study has the largest sample size. No other randomized controlled study included all the three different treatment strategies and a positive control. It is also the first associated randomized controlled trial outside Europe.

Stretchable OFET Memories: Tuning the Morphology and the Charge-Trapping Ability of Conjugated Block Copolymers through Soft Segment Branching

The mechanical properties and structural design flexibility of charge-trapping polymer electrets have led to their widespread use in organic field-effect transistor (OFET) memories. For example, in the electrets of polyfluorene-based conjugated/insulating block copolymers (BCPs), the confined fiberlike polyfluorene nanostructures in the insulating polymer matrix act as effective hole-trapping sites, leading to controllable memory performance through the design of BCPs. However, few studies have reported intrinsically stretchable charge-trapping materials and their memory device applications, and a practical method to correlate the thin-film morphology of BCP electrets with their charge-trapping ability has not yet been developed. In this study, a series of new conjugated/insulating BCPs, poly(9,9-di-n-hexyl-2,7-fluorene)-block-poly(δ-decanolactone)s (PF-b-PDL_x, x = 1-3), as stretchable hole-trapping materials are reported. The linear and branched PDL blocks with comparable molecular weights were used to investigate the effect of polymer architecture on morphology and device performance. Moreover, the coverage area of the polyfluorene nanofibers on the BCP films was extracted from atomic force microscopy images, which can be correlated with the trapping density of the polymer electrets. The branched PDL segments not only improve stretchability but also tailor crystallinity and phase separation of the BCPs, thus increasing their charge-trapping ability. The OFET memory device with PF-b-PDL₃ as the electret layer exhibited the largest memory window (102 V) and could retain its performance at up to 100% strain. This research highlights the importance of the BCP design for developing stretchable charge-trapping materials.

Backbone Engineering of Diketopyrrolopyrrole-Based Conjugated Polymers through Random Terpolymerization for Improved Mobility-Stretchability Property

Conjugated polymers synthesized through random terpolymerization have recently attracted great research interest due to the synergetic effect on the polymer's crystallinity and semiconducting properties. Several studies have demonstrated the efficacy of random terpolymerization in fine-tuning the aggregation behavior and optoelectronic property of conjugated polymers to yield enhanced device performance. However, as an influential approach of backbone engineering, its efficacy in modulating the mobility-stretchability property of high-performance conjugated polymers has not been fuller explored to date. Herein, a series of random terpolymers based on the diketopyrrolopyrrole-bithiophene (DPP-2T) backbone incorporating different amounts of isoindigo (IID) unit are synthesized, and their structure-mobility-stretchability correlation is thoroughly investigated. Our results reveal that random terpolymers containing a low IID content (DPP95 and DPP90) show enhanced interchain packing and solid-state aggregation to result in improved charge-transporting performance (can reach 4 order higher) compared to the parent polymer DPP100. In addition, owing to the enriched amorphous feature, DPP95 and DPP90 deliver an improved orthogonal mobility (μ_h) of >0.01 cm² V^-1 s^-1 under a 100% strain, higher than the value (∼0.002 cm² V^-1 s^-1) of DPP100. Moreover, DPP95 even yields 20% enhanced orthogonal μ_h retention after 800 stretching-releasing cycles with 60% strain. As concluded from a series of analyses, the improved mobility-stretchability property exerted by random terpolymerization arises from the enriched amorphous feature and enhanced aggregation behavior imposed by the geometry mismatch between different acceptors (DPP and IID). This study demonstrates that backbone engineering through rational random terpolymerization not only enhances the mobility-stretchability of a conjugated polymer but also realizes a better mechanical endurance, providing a new perspective for the design of high-performance stretchable conjugated polymers.

Impact of the Requirement of Bone Mineral Density Evidence on Utilization of Anti-osteoporosis Medications, Clinical Outcome and Medical Expenditures of Patient With Hip Fracture in Taiwan

Background: Since 2011, Taiwan’s National Health Insurance Administration (NHIA) issued a regulation on the reimbursement to anti-osteoporosis medications (AOMs). This study aimed to evaluate the impact of this regulation in reimbursement on the utilization of AOMs, clinical outcomes and associated medical expenditures of patients with incident hip fractures.

Methods: By using the National Health Insurance Research Database (NHIRD), patients with incident hip fracture from 2006 to 2015 were identified as our study cohort. Patients younger than 50 years old or prescribed with AOMs within one year prior to incident fracture were excluded. Outcomes of interest were quarterly estimates of the proportion of patients who received bone mineral density (BMD) examination, who were prescribed AOMs, as well as who encountered subsequent osteoporotic fracture-related visits and associated medical expenditures. Particularly, age- and gender specific estimates were reported. An interrupted time series study design with segmented regression model was used to quantitatively explore the impact of the changes of the reimbursement criteria on the level (immediate) and trend (long-term) changes of these outcomes.

Results: Our study enrolled 118 493 patients with incident hip fracture with those patients aged older than 80 years old accounting for the largest proportion. A significantly decreased trend of AOMs prescription rates was observed immediately post regulation except for female aged between 65 and 80, while the long-term pattern showed no significant difference. However, the percentage of patients encountered subsequent osteoporotic fracture-related visit was not statistically different between pre- and post-regulation periods. Noteworthy, the policy regulation was associated with an increasing trend of osteoporotic fracture associated medical expenditures, especially for patients older than 80 years old.

Conclusion: The regulation on the reimbursement for AOMs decreased the prescribing rate of AOMs immediately although the effect did not sustain thereafter. However, higher subsequent osteoporotic fracture-related medical expenditures were introduced, especially among those very old population.

High-Performance Nonvolatile Organic Photonic Transistor Memory Devices using Conjugated Rod-Coil Materials as a Floating Gate

A novel approach for using conjugated rod-coil materials as a floating gate in the fabrication of nonvolatile photonic transistor memory devices, consisting of n-type Sol-PDI and p-type C10-DNTT, is presented. Sol-PDI and C10-DNTT are used as dual functions of charge-trapping (conjugated rod) and tunneling (insulating coil), while n-type BPE-PDI and p-type DNTT are employed as the corresponding transporting layers. By using the same conjugated rod in the memory layer and transporting channel with a self-assembled structure, both n-type and p-type memory devices exhibit a fast response, a high current contrast between "Photo-On" and "Electrical-Off" bistable states over 10⁵ , and an extremely low programing driving force of 0.1 V. The fabricated photon-driven memory devices exhibit a quick response to different wavelengths of light and a broadband light response that highlight their promising potential for light-recorder and synaptic device applications.

Study on Intrinsic Stretchability of Diketopyrrolopyrrole-Based π-Conjugated Copolymers with Poly(acryl amide) Side Chains for Organic Field-Effect Transistors

The development of a π-conjugated polymer with hydrogen-bonding moieties has aroused great attention because of the improved molecular stacking and the hydrogen-bonding network. In this study, PDPPTVT (diketopyrrolopyrrole-thiophenevinylenethiophene) and PDPPSe (diketopyrrolopyrrole-selenophene) alkylated with a carbosilane (SiC8) side chain and poly(acryl amide) (PAM)-incorporated alkyl side chain were prepared, and their structure-performance and structure-stretchability correlation were evaluated. By incorporating the DPPTVT backbone and 0, 5, 10, or 20% PAM-incorporated alkyl side chain, the μ_h value could reach 2.0, 0.97, 0.74, and 0.42 cm² V^-1 s^-1, respectively (P1 to P4). The polymer with the PDPPSe backbone and 5% PAM-incorporated alkyl side-chain (P5) exhibited the maximum μ_h value of 0.96 cm² V^-1 s^-1. By extending the PAM moiety from the backbone with alkyl spacers, the solid-state packing and edge-on orientation can be properly maintained. Surprisingly, the PAM-incorporated alkyl side-chain can provide a hydrogen-bonding network serving as sacrificial bonding to mechanical deformation. Therefore, the relevant changes in the crystallographic parameters including the crystalline size and the in-plane π-π stacking distance with a 100% external strain were less than 4 and 0.8%, respectively, from P1 to P3. Therefore, P3 achieved an excellent stretchability while maintaining its molecular orientation and charge-transporting performance. Even with 100% external strain, P3 still provided an orthogonal μ_h over 0.1 cm² V^-1 s^-1. Moreover, by substituting the TVT moiety with the Se moiety, the ductility of the backbone can be further increased when the elastic modulus decreases from 0.80 to 0.36 GPa for P2 to P5. The achieved high μ_h retention is over 20% after 500 stretching-releasing cycles with a 60% external strain perpendicular to the channel direction for the polymer composed of PDPPSe and 5% PAM content. The results manifest that our newly designed DPP with the PAM-incorporated alkyl side chain provides a promising approach to promote the intrinsic stretchability of the π-conjugated polymers.

Colistin and tylosin enhances disaccharidase activities, and improves morphology and permeability of the intestine of broilers

1. The present study focused on the potential effects of antibiotics on intestinal digestion and integrity in broilers in terms of disaccharidase activity, electrophysiological properties and morphology. 2. One-day-old Arbour Acres birds were randomly allocated to one of four treatment groups for 42 days; control, colistin (20 mg/kg), tylosin (55 mg/kg) or chlortetracycline (CTC, 55 mg/kg) groups. Colistin and tylosin supplementation, but not CTC supplementation, caused an increase in body weight gain. 3. Colistin and tylosin elevated the activities of maltase and sucrase in the mucosa of the jejunum on d 42. Age caused a gradual decrease in the short-circuit current (Isc) and conductance (Gt) of the ileum, as a measure of permeability. The Isc and Gt of the ileum were higher in the colistin-supplemented broilers than in the control birds on d 42. Tylosin- and CTC-supplemented birds displayed Isc and Gt values similar to those of the control birds. 4. Colistin supplementation increased the villus area in the jejunum and thinned the muscularis mucosae in the ileum compared with the control group. Tylosin supplementation decreased the thickness of the muscularis mucosae and the depth of crypt in the jejunum. CTC thickened the muscularis mucosae in the jejunum and ileum. 5. Colistin and tylosin exhibited a beneficial effect on intestinal digestion and integrity by enhancing disaccharidase activities and improving gut morphology and permeability.

Effect of a conjugated/elastic block sequence on the morphology and electronic properties of polythiophene based stretchable block copolymers

We report the synthesis, morphology, and electronic properties of intrinsically stretchable AB-type, ABA-type, and BAB-type block copolymers (BCPs) of poly(3-hexylthiophene) (P3HT: A block) and elastic poly(octylene oxide) (POO: B block).

Visualisation of the unmet treatment need of osteoporotic fracture in Taiwan: A nationwide cohort study

AIMS

Recent clinical guidelines have suggested that patients experience an osteoporotic fracture should initiate anti-osteoporosis medications (AOMs). However, whether clinical guidelines translate well in "real-world" practices remain questioned. This study aimed to evaluate the "real-world" prescription pattern of AOMs and visualise the unmet treatment needs in different geographical areas in Taiwan.

METHODS

Using Taiwan's National Health Insurance Research Database, we identified patients diagnosed with a hip or vertebral fracture between 2009 and 2012. The treatment rate was defined as the proportion of patients receiving AOMs within 1 year after their index fracture. The qualitative geographical information systems approach was adopted to visualise the treatment needs of postfracture patients in different geographical areas.

RESULTS

Our study included 276,492 patients diagnosed with a hip or vertebral fracture between 2009 and 2012. The proportion of patients who received AOMs within 1 year after their index fracture increased with age and differed with fracture types and sex. For patients with hip fractures, the treatment rate ranged from 3.43% to 20.88% for female patients and from 0.69% to 10.04% for male patients in different age groups. For patients with vertebral fractures, the treatment rate ranged from 3.23% to 37.08% for female patients and from 1.85% to 23.05% for male patients. Cities in the mid-northern and southern areas of Taiwan had the highest unmet treatment need, with a treatment rate of less than 15%.

CONCLUSION

The treatment rate of osteoporotic fractures with AOMs was diverse and suboptimal in Taiwan, especially among male patients. This study used a visualisation technique to display information about the treatment status in different geographical areas and help policymakers allocate resource appropriately.

Does fully-threaded Headless Compression Screw provide a length-stable fixation in undisplaced femoral neck fractures?

OBJECTIVE

Femoral neck shortening is a common complication after surgical treatment for intracapsular femoral neck fractures. This study investigated whether fully-threaded Headless Compression Screw (FTHCS) can be a more length-stable implant than partially-threaded cannulated screw (PTCS) in reducing femoral neck shortening.

METHODS

A total of 50 patients with undisplaced femoral neck fractures (17 treated by internal fixation with three FTHCS, and 33 treated by three PTCS) from 2011 to 2014 were enrolled in this study. The radiography of the hips and medical records were reviewed for proximal femur geometry and complications.

RESULTS

Significant shortening of the femoral neck length until union were noted in both group (FTHCS group: -2.5 mm, p = 0.045; PTCS group: -2.4 mm, p = 0.011). There was no significant difference in the length of femoral neck shortening between groups (p = 0.855). Age was the only significant risk factor for >5 mm of femoral neck shortening (p = 0.041). The femoral neck-shaft angle tended to reduce and become more varus in both groups (FTHCS: -2.7°, SD = 4.5, p = 0.028; PTCS: -5.0°, SD = 8.3, p = 0.002), but the differences between groups were nonsignificant (p = 0.577). The complication rates were similar between FTHCS and PTCS (17.6% and 21.2%, p > 0.999).

CONCLUSION

The FTHCSs may be a substitute for PTCSs, but it cannot prevent femoral neck shortening and varus collapse after fracture fixation. Future studies should focus on how to preserve femoral neck length and hip function after femoral neck fractures.

Unraveling the stress effects on the optical properties of stretchable rod-coil polyfluorene-poly(n-butyl acrylate) block copolymer thin films

Novel deformable and fluorescent PF-b-PBA copolymers with nanofibrillar structures were synthesized for unraveling strain-dependent optical properties.

RGB-Switchable Porous Electrospun Nanofiber Chemoprobe-Filter Prepared from Multifunctional Copolymers for Versatile Sensing of pH and Heavy Metals

Novel red-green-blue (RGB) switchable probes based on fluorescent porous electrospun (ES) nanofibers exhibiting high sensitivity to pH and mercury ions (Hg²⁺) were prepared with one type of copolymer (poly(methyl methacrylatete-co-1,8-naphthalimide derivatives-co-rhodamine derivative); poly(MMA-co-BNPTU-co-RhBAM)) by using a single-capillary spinneret. The MMA, BNPTU, and RhBAM moieties were designed to (i) permit formation of porous fibers, (ii) fluoresce for Hg²⁺ detection, and (iii) fluoresce for pH, respectively. The fluorescence emission of BNPTU (fluorescence resonance energy transfer (FRET) donor) changed from green to blue as it detected Hg²⁺. The fluorescence emission of RhBAM (FRET acceptor) was highly selective for pH, changing from nonfluorescent (pH 7) to exhibiting strong red fluorescence (pH 2). The full-color emission of the ES nanofibers included green, red, blue, purple, and white depending on the particular pH and Hg²⁺-concentration combination of the solution. The porous ES nanofibers with 30 nm pores were fabricated using hydrophobic MMA, low-boiling-point solvent, and at a high relative humidity (80%). These porous ES nanofibers had a higher surface-to-volume ratio than did the corresponding thin films, which enhanced their performance. The present study demonstrated that the FRET-based full-color-fluorescence porous nanofibrous membranes, which exhibit on-off switching and can be used as naked eye probes, have potential for application in water purification sensing filters.

Fatal lactic acidosis associated with highly active antiretroviral therapy in patients with advanced human immunodeficiency virus infection in Taiwan

Lactic acidosis (LA), a rare but life-threatening adverse effect associated with antiretroviral therapy, has been reported with an increasing frequency since the mid1990s. From June 1994 to June 2002, a total of six patients, four males and two females with a median age of 43 years (range, 30 to 74 years), had been diagnosed with LA. The estimated incidence of LA was 5.1 per 1000 patient-years (PYs) on highly active antiretroviral therapy (HAART) (95% confidence interval [95% CI], 4.5-5.5 per 1000 PYs) and 4.4 per 1000 PY on nucleoside analogues (NAs) (95% CI, 3.9-4.7 per 1000 PYs). Their median body mass index at diagnosis of LA was 17.6 kg/m2 (range 16.3 to 22.6 kg/m2). The median CD4+ lymphocyte count at the initial diagnosis of HIV infection and at the onset of LA was 38 cells/µL (range, 4 to 103 cells/µL) and 108 cells/µL (range, 79 to 224 cells/µL), respectively. The most common symptoms were nausea, vomiting, and dyspnoea. All of the patients had findings suggestive of NA-related mitochondrial toxicity, such as myositis, pancreatitis, fatty hepatitis, peripheral neuropathy or lipodystrophy. The prescribed NA related to LA were stavudine in six patients, lamivudine, five, and didanosine, one. Despite treatment, all patients died of persistent circulatory collapse following LA. The median duration from diagnosis to death was eight days (range, 4-17 days). Our report highlights that clinicians caring for patients with AIDS should be alerted to the potentially fatal LA associated with antiretroviral therapy when patients present with low body mass index, lipodystrophy, unexplained abdominal symptoms, dyspnoea, or elevated aminotransferases.

Prevalence of Toxoplasma gondii infection and incidence of toxoplasma encephalitis in non-haemophiliac HIV-1-infected adults in Taiwan

We assessed the seroprevalence of Toxoplasma gondii infection and incidence of toxoplasma encephalitis (TE) in 844 non-haemophiliac HIV-infected patients in Taiwan between June 1994 and April 2003. Approximately 70% (69.3%) of them had a baseline CD4+ lymphocyte count of 200 × 106/L or less, and more than 70% (73.9%) having initiated highly active antiretroviral therapy. The seroprevalence of T. gondii infection was 10.2%, which did not differ with sex, age, route of transmission, birth inside or outside of Taiwan, or CD4+ lymphocyte stratifications. After a median observation duration of 603 days (range, 1–3264 days), 10 (1.2%) patients developed 11 episodes of TE after a median interval of 30 days (range, 1–941 days) between enrolment and diagnosis of TE, with an incidence of 0.59 per 100 person-years (PY) (95% confidence interval, 0.56–0.63 per 100 PY). We concluded that the incidence of TE of HIV-infected patients in Taiwan was lower than that reported in western countries because of a lower seroprevalence of T. gondii infection and use of antimicrobial prophylaxis and antiretroviral therapy, although most of the patients were at the late stage of HIV infection.

Improvement of glycemic control in streptozotocin-induced diabetic rats by Atlantic salmon skin gelatin hydrolysate as the dipeptidyl-peptidase IV inhibitor

In our previous study, Atlantic salmon skin gelatin hydrolysed with flavourzyme possessed 42.5% dipeptidyl-peptidase (DPP)-IV inhibitory activity at a concentration of 5 mg mL(-1). The oral administration of the hydrolysate (FSGH) at a single dose of 300 mg per day in streptozotocin (STZ)-induced diabetic rats for 5 weeks was evaluated for its antidiabetic effect. During the 5-week experiment, body weight increased, and the food and water intake was reduced by FSGH in diabetic rats. The daily administration of FSGH for 5 weeks was effective for lowering the blood glucose levels of diabetic rats during an oral glucose tolerance test (OGTT). After the 5-week treatment, plasma DPP-IV activity was inhibited; the plasma activity of glucagon-like peptide-1 (GLP-1), insulin, and the insulin-to-glucagon ratio were increased by FSGH in diabetic rats. The results indicate that FSGH has the function of inhibiting GLP-1 degradation by DPP-IV, resulting in the enhancement of insulin secretion and improvement of glycemic control in STZ-induced diabetic rats.

Conduction control at ferroic domain walls via external stimuli

Intriguing functionalities at nano-sized domain walls have recently spawned a new paradigm for developing novel nanoelectronics due to versatile characteristics. In this study, we explore a new scenario to modulate the local conduction of ferroic domain walls. Three controlling parameters, i.e., external electrical field, magnetic field and light, are introduced to the 90° domain walls (90° DWs) of BiFeO₃. Electrical modulation is realized by electrical transport, where the mobility of 90° DWs can be altered by gating voltage. We further use the ferromagnetic/antiferromagnetic coupling to reveal the inherent magnetism at the DWs. With an established magnetic nature, magnetotransport has been conducted to introduce magnetic controlling parameter, where a giant positive magnetoresistance change can be observed up to 200%. In addition, light modulated conduction, a core factor for multifunctional applications, is successfully demonstrated (current enhancement by a factor of 2 with 11 W white lamp). These results offer new insights to discover the tunability of domain wall nanoelectronics.

Cyclophilin A and nuclear factor of activated T cells are essential in cyclosporine-mediated suppression of polyomavirus BK replication

Immunosuppressants have impacts on the development of polyomavirus-associated nephropathy. We previously demonstrated that cyclosporin A (CsA) suppressed polyomavirus BK (BKV) replication. The role of cyclophilin A (CypA) and nuclear factor of activated T cells (NFAT) in CsA-imposed suppression of BKV replication was determined in this study. Results demonstrated that knockdown of CypA but not CypB significantly reduced BKV large T antigen (TAg) expression and BKV titer. Overexpression of CypA reversed CypA siRNA-induced inhibition in BKV TAg expression. In addition, CypA overexpression attenuated the suppressive effect of CsA on TAg expression, suggesting CypA implicated in CsA-mediated anti-BKV effect. Knockdown of NFATc3 abrogated TAg expression, while overexpression of NFATc3 promoted TAg expression and augmented BKV promoter activity. NFATc3 binding to the BKV promoter was verified by chromatin immunoprecipitation assay and electrophoretic mobility shift assay. Renal histology also displayed an increase in NFATc3 expression in tubulointerstitium of BKV-associated nephropathy. Furthermore, overexpression of NFATc3 rescued CsA-mediated inhibition of BKV load and TAg expression. A CsA analog, NIM811, which cannot block NFAT functionality, failed to suppress TAg expression. In conclusion, CypA and NFAT are indispensable in BKV replication. CsA inhibits BKV replication through CypA and NFAT, which may be potential targets of anti-BKV treatment.

Intracranial pressure fluctuation during hemodialysis in renal failure patients with intracranial hemorrhage

Coagulopathy in renal failure patients often makes them vulnerable to intracranial hemorrhage. Emergency decompression to remove the hematoma and to stop bleeding is always indicated. After the surgery, hemodialysis (HD) should be arranged to maintain the BUN/Cr. level, and I/O balance. During HD, intracranial pressure in all of the patients in this study fluctuated. This phenomenon always resulted in neurological deterioration in acute or chronic renal failure. We present intracranial pressure (ICP) changes during HD in five acute or chronic renal failure patients with intracranial hemorrhage. They all underwent craniectomy or craniotomy with ICP monitors implantation. Different HD protocols were arranged for these patients and then we observed clinical results. ICP elevated during HD and resulted in severe brain swelling. This situation was one of the clinical presentations of dialysis disequilibrium syndrome (DDS). Four patients died because of this complication and one survived. ICP fluctuation seemed to be correlated with the fluid amount and frequency of HD. The prevalence and pathophysiology of DDS remain unclear. Renal failure patient with intracranial hemorrhage may be complicated with DDS when HD was performed. An attempt to reduce the fluid amount and to increase the frequency of HD might help these patients.

Colloidal cutin-like substances cross-linked to siderophore decomposition products mobilizing plutonium from contaminated soils

Relatively recently, inorganic colloids have been invoked to reconcile the apparent contradictions between expectations based on classical dissolved-phase Pu transport and field observations of "enhanced" Pu mobility (Kersting et al. Nature 1999, 397, 56-59). A new paradigm for Pu transport is mobilization and transport via biologically produced ligands. This study for the first time reports a new finding of Pu being transported, at sub-pM concentrations, by a cutin-like natural substance containing siderophore-like moieties and virtually all mobile Pu. Most likely, Pu is complexed by chelating groups derived from siderophores that are covalently bound to a backbone of cutin-derived soil degradation products, thus revealing the history of initial exposure to Pu. Features such as amphiphilicity and small size make this macromolecule an ideal collector for actinides and other metals and a vector for their dispersal. Cross-linking to the hydrophobic domains (e.g., by polysaccharides) gives this macromolecule high mobility and a means of enhancing Pu transport. This finding provides a new mechanism for Pu transport through environmental systems that would not have been predicted by Pu transport models.

Hypofractionated CyberKnife stereotactic radiosurgery for acoustic neuromas with and without association to neurofibromatosis Type 2

CyberKnife stereotactic radiosurgery (CKSRS) has been proved effective in treating intra-cranial lesions. To treat acoustic neuroma (AN) patients with or without neurofibromatosis Type 2 (NF2) associations, the functional preservation of hearing, trigeminal nerve, and facial nerve are important. Twenty-one patients were treated with hypofractionated CKSRS. Fourteen non-NF2 and seven NF2 patients were enrolled. Cranial nerve function, audiograms, and magnetic resonance images (MRI) were monitored. Mean follow-up was 15 month. Tumors with volumes ranging from 0.13 to 24.8 cm3 (mean 5.4 cm3) were irradiated with the marginal dose 1800-2000 cGy/3 fractions. Tumors were treated with an 80 to 89% isodose line (mean 83%) and mean 97.9% tumor coverage. Two patients experienced hearing deterioration (16.7%) in the non-NF2 group, and 3 patients (50%) in the NF2 group. No facial or trigeminal dysfunction, brain stem toxicity, or cerebellar edema occurred. Tumor regression was seen in 9 patients (43%) and stable in 12 patients (57%). 100% tumor control rate was achieved. Hypofractionated CKSRS was not only effective in tumor control but also excellent in hearing preservation for non-NF2 AN. But for NF2 patients, although the tumor control was remarkable, hearing preservation was modest as in non-NF2 patients.

Evaluation of optimal cerebral perfusion pressure in severe traumatic brain injury

Traumatic brain injury (TBI) is a major cause of death and disability. In the 2000 guidelines, one of the suggestions for TBI treatment was to maintain cerebral perfusion pressure (CPP) < or = 70 mmHg. But in the 2003 guidelines, the suggestion was changed to < or = 60 mmHg. There have been some discrepancies of opinions about this recommendation in recent publications. In this study, we retrospectively reviewed 305 severe TBI (STBI) patients with Glasgow Coma Scales (GCS) < or = 8 between January 1, 2002 and March 31, 2003. The study group was stratified according to use or nonuse of intracranial pressure (ICP) monitoring, ICP levels, ages, and GCS levels in order to test the correlation between CCP and the prognosis. The patients < 50-year-old, with higher GCS level, with ICP monitoring, and with ICP levels < 20 mmHg had lower mortality rates and better prognosis (GOS) (p < 0.05 or 0.001). The patients in the GCS 3-5 subgroup had a significantly lower mortality and better prognosis if the CPP value was maintained higher than 70 mmHg (p < 0.05) The optimal CPP maintained < or = 60 mmHg did not fit in all STBI patients. Our study concludes that it is critical to maintain CPP substantially higher in lower GCS level patients.

Effect of hyperbaric oxygen on patients with traumatic brain injury

Hyperbaric oxygen therapy (HBOT) is the medical therapeutic use of oxygen at a higher atmospheric pressure. The United States Food and Drug Administration have approved several clinical applications for HBOT, but HBOT in traumatic brain injury (TBI) patients has still remained in controversial. The purpose of our study is to evaluate the benefit of HBOT on the prognosis of subacute TBI patients. We prospectively enrolled 44 patients with TBI from November 1, 2004 to October 31, 2005. The study group randomly included 22 patients who received HBOT after the patients' condition stabilization, and the other 22 corresponding condition patients were assigned into the matched control group who were not treated with HBOT. The clinical conditions of the patients were evaluated with the Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) before and 3 to 6 months after HBOT. The GCS of the HBOT group was improved from 11.1 to 13.5 in average, and from 10.4 to 11.5 (p < 0.05) for control group. Among those patients with GOS = 4 before the HBOT, significant GOS improvement was observed in the HBOT group 6 months after HBOT. Based on this study, HBOT can provide some benefits for the subacute TBI patients with minimal adverse side effects.

Neurotrauma research in Taiwan

Because of the rapid industrial and economic growth, Taiwan and other developing countries have faced an enormous increase in the number of motorcycles, which has subsequently caused a rapid increase of the motorcycle-related traumatic brain injuries (TBI). In order to tackle this serious problem, stepwise approaches for TBI were implemented in Taiwan from 1991 to 2007. Step 1 was to do a nationwide TBI registry in order to identify the risk factors and determinants. We found that the major cause of TBI in Taiwan was motorcycle-related injury, and very few motorcyclists wore a helmet. Step 2 was to launch the implementation of the helmet use law on June 1, 1997. A rapid decline of TBI hospitalizations and deaths was demonstrated soon thereafter. Step 3 was to enroll into international collaborations with the Global Spine and Head Injury Prevention Project (Global SHIP Project) groups for TBI. The comparative results thus obtained could be used to develop prevention strategies for developing countries. Step 4 was to implement clinical researches for TBI, which included a Propofol study, hyperbaric oxygen therapy (HBOT), brain parenchymal oxygen (PbtO2) monitoring, etc. Step 5 was to develop guidelines for the management of severe TBI in Taiwan. Through a 2-year period of review, discussion, and integration, a 9-chapter guideline was published in June 2007. In summary, our experience and process for management of TBI in Taiwan can be used as a reference for other developing countries.

Heterogeneous catalytic oxidation of hypophosphite by H2O2: pH effect

Phosphorus chemicals control key aspects of eutrophication and other environmental process. Hypophosphite (HP) originating from manmade and natural sources was evidenced as present in the environment and was investigated rarely. Recently, iron oxide has been used as a catalyst for oxidising organic contaminants with hydrogen peroxide (i.e. heterogeneous Fenton-like reaction). This study focused mainly on the oxidation of 1.0 mM HP by hydrogen peroxide in the presence of a novel iron oxide catalyst (B1 catalyst) which was prepared through a fluidised-bed Fenton reactor (FBR-Fenton). The background experiments including the oxidation experiment of HP by air only, by H2O2 only and adsorption of HP by B1 catalyst were first elucidated. It was found that HP could not be oxidised at all by air and H2O2 at pH 2.5-12 in 24 hours. On the other hand, it could be adsorbed by B1 catalyst with 89.8% removal at pH 2.5 in 5 hours and complete desorption at pH 11.0. Then, we investigated the effects of pH and Fe leaching from the catalyst on the oxidative efficiency of HP. We found that although the removal rate of HP at pH 2.5 is faster than that at pH 4.0, B1 catalyst has a higher HP oxidation efficiency at pH 4.0 than that at pH 2.5. We conclude that it is a major heterogeneous catalytic oxidation by our novel iron oxide catalyst to oxidise HP at pH 4.0. Also, B1 could be a useful and potential catalyst for the treatment of HP wastewater.

Effects of internal medicine residency training in AIDS care in Taiwan

Having contact and interacting with HIV/AIDS patients has long been recognized as a means for improving AIDS-related knowledge and attitudes among physicians and hence for increasing their intention to provide AIDS care. To investigate the impact of one-month residency training in an AIDS inpatient unit on internal medicine residents, this quasi-experimental, pre-post, two-group study, conducted from April 2000 to April 2001, used questionnaires. At follow-up, residents who received training in the AIDS unit (experimental group) were significantly more knowledgeable about HIV/AIDS, had more positive attitudes and greater intention to care for HIV-infected patients than residents who did not receive this training (control group). Results suggest that a one-month AIDS residency training intervention can effectively enhance residents' HIV-related knowledge, attitudes and intention to care for patients infected with HIV.

Lipid peroxidation: a possible role in the induction and progression of chronic periodontitis

OBJECTIVES

Reactive oxygen species (ROS) are implicated in the destruction of the periodontium during inflammatory periodontal diseases. The imbalance in oxidant/antioxidant activity may be a key factor in the damaging effects of ROS. This study aimed to determine the lipid peroxidation levels in gingival crevicular fluid and saliva, and glutathione (GSH) and glutathione peroxidase (GPx) in saliva in patients with chronic periodontitis.

METHODS

Gingival crevicular fluid and saliva were collected from 13 patients and 9 healthy control subjects during the preliminary study, and from 21 patients during the subsequent study. Lipid peroxidation level, GSH level and GPx activity were determined by spectrophotometric assay.

RESULTS

The preliminary study found that when comparing patients to healthy controls, the gingival crevicular fluid samples produced the following results, respectively: higher lipid peroxidation concentration (microm) (by sites: 167.55 vs. 53.71, p < 0.0001; by subjects: 151.99 vs. 50.66, p < 0.005) and total amount (pmol) (by sites: 93.02 vs. 8.47, p < 0.0001, by subjects: 80.44 vs. 7.84, p < 0.0005). In saliva samples, lower GSH concentration (microm) (373.04 vs. 606.67, p < 0.05), higher lipid peroxidation concentration (microm) (0.66 vs. 0.13, p < 0.0005), and no difference in GPx activity were found in patients than in those of healthy controls. The subsequent study showed statistically significant (p < 0.05) improvement of clinical periodontal parameters (plaque index, gingival index, probing attachment level, probing pocket depth and gingival crevicular fluid volume), decreases in gingival crevicular fluid lipid peroxidation levels (concentration and total amount) at the sites after the completion of phase 1 periodontal treatment. Similarly, the periodontal treatment resulted in a significant decrease of lipid peroxidation concentrations (p < 0.05), increase in GSH concentration (p < 0.001), and no change in GPx activity in saliva samples.

CONCLUSION

The increased levels of lipid peroxidation may play a role in the inflammation and destruction of the periodontium in periodontitis.

Epidural abscess in an obstetric patient with patient-controlled epidural analgesia – a case report

We present the case of a 37-year-old pregnant woman who underwent a cesarean section due to previous cesarean delivery. Spinal anesthesia was performed at the L2-3 intervertebral space with an epidural catheter inserted at L1-2 for postoperative patient-controlled epidural analgesia. When the epidural catheter was removed on day three, an area of redness round the entry point was noted and the patient complained of low back pain, but was discharged from hospital. Later the same day, she felt backache so severe that she was unable to stand up or bend her body. She called for help and was sent to our emergency room. Physicians noted a small amount of discharge from the insertion site, and the body temperature was elevated to 38 degrees C. An anesthesiologist and an infectious disease specialist were consulted, and an epidural abscess was suspected. Urgent magnetic resonance imaging revealed an epidural abscess at L1-2. After five days of unsuccessful treatment with oxacillin, a 28-day course of vancomycin, followed by two months of oral fusidic acid, resulted in complete remission of the epidural abscess. The patient has remained free of neurologic deficit.

Successful discontinuation of fluconazole as secondary prophylaxis for cryptococcosis in AIDS patients responding to highly active antiretroviral therapy

Seven AIDS patients with disseminated cryptococcosis who had had immune reconstitution following highly active antiretroviral therapy (HAART) had discontinued their secondary antifungal prophylaxis to prevent relapse of Cryptococcus neoformans infection. The median CD4+ count was 236 cells/ micro L (range, 117-404 cells/ micro L; mean, 247 cells/ micro L) and the plasma viral loads were undetectable in five patients at discontinuation of antifungal prophylaxis. No relapse of cryptococcosis was detected in these patients after a median observation duration of nine months (range, 5.5-4.1 months, mean, 14.6 months) following discontinuation. Our data and review of the literature suggest that discontinuation of fluconazole prophylaxis is safe in patients with reconstitution of immunity following#10; initiation of HAART.

Variations in the NRAMP1 gene and susceptibility of tuberculosis in Taiwanese

SETTING

National Taiwan University Hospital, Taipei, Taiwan.

OBJECTIVE

To study the variations in the NRAMP1 gene using five genotypes (274C/T, 577-18G/A, A318V, D543N and 3' untranslated region [UTR]), and the susceptibility of tuberculosis and HIV infection in Taiwanese.

DESIGN

The study sample included 49 patients with tuberculosis, 48 healthy control subjects and 60 HIV-infected patients. The polymerase chain reaction (PCR) products amplified from their genomic DNA were subjected to restriction enzyme digestion and were analysed using agarose gel electrophoresis.

RESULTS

A318V was not polymorphic in the studied population. Only D543N and 3'UTR were more heterozygous. In 274 C/T and 577-18G/A, the allele frequencies showed the predominant type to be the homozygous patterns C/C (94%) and G/G (94%), respectively. There were no statistically significant differences between the tuberculosis patients and the healthy control subjects. Despite the high susceptibility to Mycobacterium tuberculosis in HIV-infected patients, genotypic frequencies in the HIV-positive patients were not significantly different between tuberculous (n = 29) and non-tuberculous patients (n = 31). In comparison with previous studies, there were significant differences between different ethnic groups in allele frequencies for 274C/T, D543N and 3'UTR.

CONCLUSION

The allele and genotype of NRAMPI polymorphism among Taiwanese differed from those of Caucasians, Africans and Hispanics. No allelic associations were identified between the NRAMP1 alleles and tuberculosis susceptibility.

Systematic search for mutations in the human tissue inhibitor of metalloproteinases-3 (TIMP-3) gene on chromosome 22 and association study with schizophrenia

Several linkage studies have suggested that chromosome 22q12-q13 is a putative region for schizophrenic genes. In this study, the human tissue inhibitor of metalloproteinase-3 (TIMP-3) gene was investigated as positional candidate gene for schizophrenia because of its regulatory function on extracellular matrix proteins, cell adhesion molecules, and neural cell adhesion molecules in the brain. We systematically searched for the nucleotide variants by sequencing all the exons and their flanking intronic sequences in a sample of Chinese schizophrenic patients from Taiwan. Two silent mutations in the exon 3 were identified: c.249T-->C at codon 83 (His) and c.261C-->T at codon 87 (Ser). However, no mutations causing amino acid alteration or aberrant splicing of transcripts were observed. Hence, it is unlikely that the TIMP-3 gene itself may play an important role in the genetic susceptibility to schizophrenia. Further case control association study revealed a significant difference of genotype distribution of the c.249T-->C between schizophrenic patients and control. This finding supports that 22q12 is a schizophrenia susceptible region, and it is likely that there might be other genetic mutations in the neighborhood of the TIMP-3 gene locus that may contribute to the susceptibility of schizophrenia.

Identifications, classification, and evolution of the vertebrate alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor subunit genes

The AMPA receptor (AMPAR), a pharmacologically defined ionotropic glutamate receptor, mediates fast excitatory synaptic transmission in the vertebrate central nervous system. Mammalian and avian AMPARs are assembled from the products of four genes (GRIA1-GRIA4) conserved in their translated sequences and gene organizations. Teleost fish also express AMPAR subunits; however, the AMPAR genes have not been extensively investigated in lower vertebrates. To elucidate the evolution of vertebrate AMPAR genes, reverse-transcriptase PCR-based surveys of subunits expressed in the brains of eight nonmammalian vertebrates were performed. The newly cloned vertebrate AMPAR subunits were classified by their sequence identities to the mammalian AMPAR subunits. The results of molecular and phylogenetic analyses indicated that the members of the AMPAR gene family increased from two in the jawless hagfish to four in the tetrapods and the shark and to more than four in the teleost fish. The sizes of AMPAR gene families correlate well with those of many multigene families observed in various vertebrates. Moreover, all vertebrates expressed at least one AMPAR subunit bearing an arginine (R) at the Q/R site, at which no invertebrate glutamate receptor subunit has been found to have an R residue, suggesting that the low calcium-permeable AMPARs appeared at early evolutionary stages of vertebrate central nervous systems. Uniquely, the loop 1 (L1) regions between hydrophobic domain 1 and hydrophobic domain 2 of the hagfish putative GRIA2 and all the teleost GRIA1 subunits were much longer than those of the remaining known ionotropic glutamate receptor subunits. The length and sequence of the L1 of teleost GRIA1 subunits were heterogeneous, suggesting that the amino acid residues in L1 were not highly selected.

Association between cytomegalovirus-specific reactivity of T cell subsets and development of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome

The association between cytomegalovirus (CMV)-specific reactivity of T cell subsets and development of CMV retinitis (CMV-R) was prospectively studied in 50 CMV-seropositive AIDS patients. The frequency of CMV-specific CD69 expression on CD8 T cells was similar in patients with and patients without CMV-R (median, 1.0% vs. 1.2%; P=.14). However, the frequency of CMV-specific CD69 expression on CD4 T cells was significantly lower in patients with CMV-R than in those without CMV-R (median, 0.4% vs. 2.25%; P<.001). CMV-specific CD4 T cell reactivity in patients who developed CMV-R shortly after starting highly active antiretroviral therapy (HAART) remained low, although the CD4 cell counts increased markedly. Therefore, development of CMV-R is associated with a poor CMV-specific reactivity of CD4 T cells but not with poor reactivity of CD8 T cells. Development of CMV-R after initiation of HAART is associated with a poor reconstitution of CMV-specific immune response, rather than with immune rebound.

Kinetics of antigen-induced phenotypic and functional maturation of human monocyte-derived dendritic cells

Dendritic cells (DCs), a critical component of innate immunity, are the most potent APCs. When DCs mature, they can elicit strong T cell responses. We studied the kinetics of Ag-induced phenotypic and functional maturation of human monocyte-derived DCs using an in vitro T cell-independent culture system. With this model, we herein show that an Ag that has recently or repetitively been exposed ("exposed Ag") rapidly induces a high level of maturation; however, an Ag that has never or only remotely been exposed ("unexposed Ag") slowly induces a low level of maturation. The kinetics of Ag-induced maturation of DCs possibly implies a novel mechanism for immunological memory that would provide maximal host protection from repetitively invading pathogens in the environment.