Breathing-Driven Self-Powered Pyroelectric ZnO Integrated Face Mask for Bioprotection

Rapid spread of infectious diseases is a global threat and has an adverse impact on human health, livelihood, and economic stability, as manifested in the ongoing coronavirus disease 2019 (COVID-19) pandemic. Even though people wear a face mask as protective equipment, direct disinfection of the pathogens is barely feasible, which thereby urges the development of biocidal agents. Meanwhile, repetitive respiration generates temperature variation wherein the heat is regrettably wasted. Herein, a biocidal ZnO nanorod-modified paper (ZNR-paper) composite that is 1) integrated on a face mask, 2) harvests waste breathing-driven thermal energy, 3) facilitates the pyrocatalytic production of reactive oxygen species (ROS), and ultimately 4) exhibits antibacterial and antiviral performance is proposed. Furthermore, in situ generated compressive/tensile strain of the composite by being attached to a curved mask is investigated for high pyroelectricity. The anisotropic ZNR distortion in the bent composite is verified with changes in ZnO bond lengths and OZnO bond angles in a ZnO₄ tetrahedron, resulting in an increased polarization state and possibly contributing to the following pyroelectricity. The enhanced pyroelectric behavior is demonstrated by efficient ROS production and notable bioprotection. This study exploring the pre-strain effect on the pyroelectricity of ZNR-paper might provide new insights into the piezo-/pyroelectric material-based applications.

Laser-Shock-Driven In Situ Evolution of Atomic Defect and Piezoelectricity in Graphitic Carbon Nitride for the Ionization in Mass Spectrometry

Nanostructures─coupled with mass spectrometry─have been intensively investigated to improve the detection sensitivity and reproducibility of small biomolecules in laser desorption/ionization mass spectrometry (LDI-MS). However, the impact of laser-induced shock wave on the ionization of the nanostructures has rarely been reported. Herein, we systematically elucidate the laser shock wave effect on the ionization in terms of the in situ development of atomic defects and piezoelectricity in two-dimensional graphitic carbon nitride nanosheets (g-C₃N₄ NS) by short laser pulses. The mass analysis results of immunosuppressive drugs verify the enhanced LDI-MS performance, structurally originating from anisotropic lattice distortions in g-C₃N₄ NS, i.e., in-plane extension (contraction) and out-of-plane contraction (extension) that modulate the charge carrier motion. Along with the experimental investigations, density functional theory calculations on Mulliken charges and dipole moments demonstrate the contribution of defect and piezoelectricity to the ionization. The results of this study provide a mechanistic understanding of the underlying ionization processes, which is crucial for revealing the full potential of laser shock waves in LDI-MS.

Laser desorption/ionization mass spectrometry of L-thyroxine (T4) using combi-matrix of α-cyano-4-hydroxycinnamic acid (CHCA) and graphene

An optimal combi-matrix for MALDI-TOF mass spectrometry was presented for the analysis of L-thyroxine (T4) in human serum. For the selection of the optimal combi-matrix, several kinds of combi-matrices were prepared by mixing the conventional organic matrix of CHCA with nanomaterials, such as graphene, carbon nanotubes, nanoparticles of Pt and TiO2. In order to select the optimal combi-matrix, the absorption at the wavelength of laser radiation (337 nm) for the ionization of sample was estimated using UV–Vis spectrometry. And, the heat absorption properties of these combi-matrices were also analyzed using differential scanning calorimetry (DSC), such as onset temperature and fusion enthalpy. In the case of the combi-matrix of CHCA and graphene, the onset temperature and fusion enthalpy were observed to be lower than those of CHCA, which represented the enhanced transfer of heat to the analyte in comparison with CHCA. From the analysis of optical and thermal properties, the combi-matrix of CHCA and graphene was selected to be an optimal combination for the transfer of laser energy during MALDI-TOF mass spectrometry. The feasibility of the combi-matrix composed of CHCA and graphene was demonstrated for the analysis of T4 molecules using MALDI-TOF mass spectrometry. The combi-matrix of CHCA and graphene was estimated to have an improved limit of detection and a wider detection range in comparison with other kinds of combi-matrices. Finally, the MALDI-TOF MS results of T4 analysis using combi-matrix were statistically compared with those of the conventional immunoassay.

Quantitative analysis of vitamin D using m/MALDI-TOF mass spectrometry based on a parylene matrix chip

Vitamin D deficiency is associated with various disorders and is diagnosed based on the concentration of 25-hydroxy vitamin D3 (25(OH)D3) in serum. The parylene matrix chip was fabricated to reduce the matrix background noise, and the homogenous distribution of the matrix was retained for the quantitative analysis of 25(OH)D3. The Amplex Red assay was performed to confirm that the sample-matrix mixing zone of the parylene matrix chip was formed below the surface of the parylene-N film. The homogeneous distribution of the matrix was verified from the fluorescence image. For effective analysis using a parylene matrix chip, 25(OH)D3 was modified through the nucleophilic addition of betaine aldehyde (BA) to form a hemiacetal salt. Such modified 25(OH)D3 with a positive charge from BA could be effectively analyzed using MALDI-TOF mass spectrometry. Serum 25(OH)D3 was extracted by liquid–liquid extraction (LLE) and quantified using MALDI-TOF mass spectrometry based on the parylene matrix chip. The intensity of the mass peak of 25(OH)D3 was linearly correlated (r2 = 0.992) with the concentration of 25(OH)D3 spiked in serum, and the LOD was 0.0056 pmol/μL. Energy drinks and vitamin D3 tablets were also employed for the real sample analysis. Finally, the results of the chemiluminescence binding assay and MALDI-TOF mass spectrometry were statistically analyzed to determine the applicability of the method using the Bland–Altman test and Passing–Bablok regression.

Simultaneous analysis of acylcarnitines using MALDI-TOF mass spectrometry based on a parylene matrix chip

Short and medium chain acylcarnitines have been used for the diagnosis of various fatty acid oxidation and organic acid disorders. This report presents a multiplex and quantitative analysis of acylcarnitines...

Photothermal Structural Dynamics of Au Nanofurnace for In Situ Enhancement in Desorption and Ionization

Fundamental properties of nanostructured substrates govern the performance of laser desorption/ionization mass spectrometry (LDI-MS); however, limited studies have elucidated the desorption/ionization mechanism based on the physicochemical properties of substrates. Herein, the enhancement in desorption/ionization is investigated using a hybrid matrix of Au nanoisland-functionalized ZnO nanotubes (AuNI-ZNTs). The underlying origin is explored in terms of the photo-electronic and -thermal properties of the matrix. This is the first study to report the effect of laser-induced surface restructuring/melting phenomenon on the LDI-MS performance. AuNI plays a central role as a photothermal nanofurnace, which facilitates the internal energy transfer from the AuNI to the adsorbed analytes by reconstruction in the structurally dynamic AuNI and therefore favors the desorption process. Moreover, piezoelectricity is driven in situ in the AuNI-ZNT hybrid, which modulates the overall band structure and thereby promotes the ionization process. Ultimately, high LDI-MS performance is demonstrated by analyzing small metabolites of fatty acids and monosaccharides, which are challenged to be detected in conventional LDI-MS. This study emphasizing the understanding of matrix properties can provide insights into the design and development of a novel nanomaterial as an efficient LDI matrix. Furthermore, the developed hybrid matrix can overcome the major hurdles existing in conventional LDI-MS.

Quantitative analysis of galactose using LDI-TOF MS based on a TiO2 nanowire chip

A novel method for quantifying galactose was developed to serve as a newborn screening test for galactosemia using laser desorption/ionization time-of-flight (LDI-TOF) mass spectrometry (MS) with a TiO2 nanowire chip. Herein, phosphate citrate buffer, serum, and dried blood spot (DBS) were employed for the quantitative analysis of galactose. To quantitatively analyze galactose, its reduction potential was used to oxidize o-phenylene diamine (OPD) into 2,3-diaminophenazine (DA), which were both detected using LDI-TOF MS with a TiO2 nanowire chip according to the concentration of galactose. The reproducibility and the interference of glucose were determined to demonstrate the applicability of this method. Moreover, mixtures of galactose, phenylalanine, and 17 α-OHP were analyzed to determine the interference induced by other biomarkers of metabolic disorders. The OPD oxidation of galactose was found to be selectively achieved under high-glucose conditions, similar to human blood, thereby showing good reproducibility. The intensities of the mass peaks of OPD and DA based on LDI-TOF MS with a TiO2 nanowire chip were linearly correlated in the galactose concentration range of 57.2–220.0 μg/mL (r2 = 0.999 and 0.950, respectively) for serum samples and 52.5–220.0 μg/mL (r2 = 0.993 and 0.985, respectively) for DBS after methanol precipitation/extraction. The enzyme immunoassay and LDI-TOF MS analysis results were statistically analyzed, and a mixture of phenylalanine, 17 α-OHP, and galactose was simultaneously investigated quantitatively at the cutoff level.

Simultaneous Analysis of Multiple Cancer Biomarkers Using MALDI-TOF Mass Spectrometry Based on a Parylene-Matrix Chip

Recently, the parylene-matrix chip was developed for quantitative analysis of small molecules less than 1 kDa. In this study, MALDI-TOF MS based on the parylene-matrix chip was performed to clinically diagnose intrahepatic cholangiocarcinoma (IHCC) and colorectal cancer (CRC). The parylene-matrix chip was applied for the detection of small cancer biomarkers, including N-methyl-2-pyridone-5-carboxamide (2PY), glutamine, lysophosphatidylcholine (LPC) 16:0, and LPC 18:0. The feasibility of MALDI-TOF MS based on the parylene-matrix chip was confirmed via analysis of spot-to-spot and shot-to-shot reproducibility. Serum metabolite markers of IHCC, N-methyl-2-pyridone-5-carboxamide (2PY), and glutamine were quantified using MALDI-TOF MS based on the parylene-matrix chip. For clinical diagnosis of CRC, two water-insoluble (barely soluble) biomarkers, lysophosphatidylcholine (LPC) 16:0 and LPC 18:0, were quantified. Finally, glutamine and LPC 16:0 were simultaneously detected at a range of concentrations in sera from colon cancer patients using the parylene-matrix chip. Thus, this method yielded high-throughput detection of cancer biomarkers for the mixture samples of water-soluble analytes (2PY and glutamine) and water-insoluble analytes (LPC 16:0 and LPC 18:0).

A TiO2 nanowire photocatalyst for dual-ion production in laser desorption/ionization (LDI) mass spectrometry

It has been challenging to detect small analytes in both positive and negative ion modes in MALDI-MS. Herein, TiO₂ nanowires are presented as a solid matrix to produce dual-ion of any analytes and to demonstrate the versatile applicability in LDI-MS.

Nanostructured TiO2 Materials for Analysis of Gout-Related Crystals Using Laser Desorption/Ionization Time-of-Flight (LDI-ToF) Mass Spectrometry

Crystals of monosodium urate monohydrate (MSU) and calcium pyrophosphate dihydrate (CPPD) are known to induce arthropathic diseases called gout and pseudogout, respectively. These crystals are deposited in various joints or tissues, causing severe pain. Correct identification of crystals is crucial for the appropriate treatment of gout and pseudogout, which exhibit very similar symptoms. Herein, a novel approach of laser desorption/ionization time-of-flight (LDI-ToF) mass spectrometry (MS) was introduced to analyze MSU and CPPD crystals with three different types of nanostructured TiO₂ materials including TiO₂ nanoparticles (P25), TiO₂ nanowires synthesized from wet-corrosion method, and the mixture of P25 and TiO₂ nanowires (P25/TiO₂ nanowires) as inorganic solid matrices. Furthermore, the feasibility of LDI-ToF MS based on these TiO₂ nanostructures for the analysis of the two arthropathy-related crystals was tested using spiked samples in synovial fluid at known crystal concentrations. The mass analysis results of MSU and CPPD crystals demonstrated that (1) the electrostatic interaction between analytes and solid matrices was key for the analyte ionization and (2) LDI-ToF MS with nanostructured TiO₂ materials has the potential to be a practical approach for the diagnosis of gout and pseudogout.

Synergistic Effect of the Heterostructure of Au Nanoislands on TiO2 Nanowires for Efficient Ionization in Laser Desorption/Ionization Mass Spectrometry

A combination nanostructured matrix with metal Au nanoislands and semiconductor TiO₂ nanowires is presented to enhance both desorption and ionization efficiency in laser desorption/ionization (LDI) mass spectrometry. The heterostructure of Au nanoislands on TiO₂ nanowires was fabricated via (1) TiO₂ nanowire synthesis through a modified wet-corrosion method and (2) Au nanoisland formation through thermal annealing of a sputtered Au layer on the TiO₂ nanowires. Herein, the synergistic effect of this heterostructure for highly efficient ion production was experimentally elucidated in terms of the formation of high temperature on the surface of Au and the creation of a Schottky barrier at the Au-TiO₂ interface. Finally, four types of immunosuppressors were analyzed to demonstrate the improved ionization performance of the heterostructure for LDI mass spectrometry.

Gold-nanoparticle-coated magnetic beads for concentration and ionization of analytes for laser desorption/ionization mass spectrometry

RATIONALE

Magnetic particles coated with gold nanoparticles (Au NPs) (Au-MAGs) were developed and used (1) for sample concentration and (2) as a solid matrix for laser adsorption/desorption mass spectrometry (LDI-MS).

METHODS

The Au-MAGs were prepared by (1) coating polystyrene on iron oxide NPs (PS-MNPs), (2) coating poly-l-lysine on the PS-MNPs (PLL-coated PS-MNPs), and (3) coating negatively charged Au NPs on the PLL-coated PS-MNPs (Au-MAGs).

RESULTS

The Au-MAGs were used to concentrate the target analyte by means of electrostatic interactions between the positively charged GHP9 and the negatively charged Au-MAGs as well as selective interactions (such as gold-sulfur interactions) between glutathione (GSH) and Au-MAGs. Then, the concentrated analyte could be ionized for LDI-MS.

CONCLUSIONS

The Au-MAGs were demonstrated (1) to concentrate the target analyte in a sample solution, tested by electrostatic interactions and selective interactions between gold and sulfur and (2) to ionize the concentrated analyte for LDI-MS.

TiO2 Nanowires from Wet-Corrosion Synthesis for Peptide Sequencing Using Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

In this work, TiO₂ nanowires synthesized from a wet-corrosion process were presented for peptide sequencing by photocatalytic reaction with UV radiation. For the photocatalytic decomposition of peptides, the peptide sample was dropped on a target plate containing synthesized TiO₂ nanowire zones and UV-irradiated. Subsequently, the target plate was analyzed by laser desorption/ionization time-of-flight (LDI-TOF) mass spectrometry using the synthesized TiO₂ nanowires as a solid matrix. The feasibility of peptide sequencing based on the photocatalytic reaction with the synthesized TiO₂ nanowires was demonstrated using six types of peptides GHP9 (G₁-H-P-Q-G₂-K₁-K₂-K₃-K₄, 1006.59 Da), BPA-1(K₁-S₁-L-E-N-S₂-Y-G₁-G₂-G₃-K₂-K₃-K₄, 1394.74 Da), PreS1(F₁-G-A-N₁-S-N₂-N₃-P₁-D₁-W-D₂-F₂-N₄-P₂-N₅, 1707.68 Da), HPQ peptide-1 (G-Y-H-P-Q-R-K, 884.45 Da), HPQ peptide-2 (K-R-H-P-Q-Y-G, 884.45 Da), and HPQ peptide-3 (R-Y-H-P-Q-G-K, 884.45 Da). The identification of three different peptides with the same molecular weight was also demonstrated by using the synthesized TiO₂ nanowires for their photocatalytic decomposition as well as for LDI-TOF mass spectrometry as a solid-matrix.

Detection of bovine coronavirus in nasal swab of non-captive wild water deer, Korea

Bovine coronavirus (BCoV) is a causative agent of respiratory and enteric diseases in cattle and calves. BCoV infection was also evident in captive wild ruminants. Recently, water deer are recognized as the most common wildlife to approach farmhouses and livestock barns in Korea. Therefore, we investigated 77 nasal swab samples from non‐captive wild water deer (Hydropotes inermis) between November 2016 and September 2017 and identified three samples positive for coronavirus, indicating potential for respiratory shedding. The full genomic sequences of the water deer coronavirus were closely related to BCoV (>98%). Therefore, effective biosecurity system in bovine farms would be necessary to prevent contact between farm ruminants and free‐ranging wild water deer.

Detection of Severe Acute Respiratory Syndrome-Like, Middle East Respiratory Syndrome-Like Bat Coronaviruses and Group H Rotavirus in Faeces of Korean Bats

Bat species around the world have recently been recognized as major reservoirs of several zoonotic viruses, such as severe acute respiratory syndrome coronavirus (SARS‐CoV), Middle East respiratory syndrome coronavirus (MERS‐CoV), Nipah virus and Hendra virus. In this study, consensus primer‐based reverse transcriptase polymerase chain reactions (RT‐PCRs) and high‐throughput sequencing were performed to investigate viruses in bat faecal samples collected at 11 natural bat habitat sites from July to December 2015 in Korea. Diverse coronaviruses were first detected in Korean bat faeces, including alphacoronaviruses, SARS‐CoV‐like and MERS‐CoV‐like betacoronaviruses. In addition, we identified a novel bat rotavirus belonging to group H rotavirus which has only been described in human and pigs until now. Therefore, our results suggest the need for continuing surveillance and additional virological studies in domestic bat.

Analysis of benzylpenicillin in milk using MALDI-TOF mass spectrometry with top-down synthesized TiO2 nanowires as the solid matrix

In this work, the wet-corrosion process for the synthesis of titanium oxide (TiO2) nanowires in the anatase phase was optimized as the solid matrix in MALDI-TOF mass spectrometry, and the solid matrix of the TiO2 nanowires was applied to the detection of antibiotics in a daily milk sample. The influence of the alkali concentration and the heat treatment temperature on the crystal structure of the TiO2 nanowires was investigated. The ionization activity of the TiO2 nanowires was estimated for each synthetic condition using amino acids as model analytes with low molecular weights. For the detection of antibiotics in milk, benzylpenicillin was spiked in daily milk samples, and MALDI-TOF mass spectrometry with the TiO2 nanowires was demonstrated to detect the benzylpenicillin at the cut-off concentration of the EU directive.

Nylon nanoweb with TiO2 nanoparticles as a solid matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

RATIONALE

The solid matrices used for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) enable the analysis of small molecules by preventing fragmentations of organic matrix molecules in the low mass-to-charge ratio (m/z) range. In this work, a nylon nanoweb with TiO(2) particles was developed as a solid matrix for MALDI-TOFMS to improve the low intensities of mass peaks, narrow detection ranges and low signal-to-noise levels.

METHODS

The nylon nanoweb with TiO(2) particles was prepared by simultaneously electrospinning a nylon nanoweb and electrospraying TiO(2) nanoparticles measuring 25 nm in diameter to form TiO(2) spheres 300 nm in diameter.

RESULTS

MS of multiple analytes was demonstrated in the low molecular weight range using eight amino acids. Additionally, leucine-enkephalin (555.6 g/mol) and cyclic citrullinated peptide (1668 g/mol) were used as model analytes to test the feasibility of a nylon nanoweb containing TiO(2) particles as a solid matrix for MALDI-TOFMS.

CONCLUSIONS

The nylon nanoweb with TiO(2) particles can be applied for the detection of volatile small molecule analytes in the m/z ratio range of small molecules.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of small volatile molecules using a parylene-matrix chip

RATIONALE

In matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS), volatile small molecules have been nearly impossible to analyze because (1) such molecules evaporate under drying and vacuum conditions and (2) the organic matrix creates matrix peaks in the low mass-to-charge (m/z) range (m/z <500). In this work, the analysis of volatile small molecules using MALDI-TOFMS was realized using (1) a parylene-matrix chip to eliminate the matrix peaks of the organic matrix and (2) graphene for the effective adsorption of the small volatile molecules.

METHODS

The parylene-matrix chip was produced by deposition of a partially porous parylene-N thin film on a dried organic matrix array. The sample solution of volatile small molecules was mixed with the graphene and then placed on the parylene-matrix chip for MALDI-TOFMS. Analogs of chemical agents called dimethyl methyl phosphonate (DMMP) and 2-chloroethylethylsulfide (CEES) were used as model compounds for the small volatile molecules, and the sensing parameters were estimated, such as the limit of detection (LOD) and the detection range.

RESULTS

MALDI-TOFMS based on the parylene-matrix chip and graphene as the adsorbent could achieve a LOD of approximately 1 ppb in the detection range of 1 ppm-1 ppb for the highly volatile DMMP and CEES.

CONCLUSIONS

The parylene-matrix chip with graphene can be applied for the detection of volatile small molecule analytes in the m/z ratio range of small molecules (m/z <500) using graphene as an effective adsorbent.

Performance-driven facial animation: basic research on human judgments of emotional state in facial avatars

Virtual reality is rapidly evolving into a pragmatically usable technology for mental health (MH) applications. As the underlying enabling technologies continue to evolve and allow us to design more useful and usable structural virtual environments (VEs), the next important challenge will involve populating these environments with virtual representations of humans (avatars). This will be vital to create mental health VEs that leverage the use of avatars for applications that require human-human interaction and communication. As Alessi et al.1 pointed out at the 8th Annual Medicine Meets Virtual Reality Conference (MMVR8), virtual humans have mainly appeared in MH applications to "serve the role of props, rather than humans." More believable avatars inhabiting VEs would open up possibilities for MH applications that address social interaction, communication, instruction, assessment, and rehabilitation issues. They could also serve to enhance realism that might in turn promote the experience of presence in VR. Additionally, it will soon be possible to use computer-generated avatars that serve to provide believable dynamic facial and bodily representations of individuals communicating from a distance in real time. This could support the delivery, in shared virtual environments, of more natural human interaction styles, similar to what is used in real life between people. These techniques could enhance communication and interaction by leveraging our natural sensing and perceiving capabilities and offer the potential to model human-computer-human interaction after human-human interaction. To enhance the authenticity of virtual human representations, advances in the rendering of facial and gestural behaviors that support implicit communication will be needed. In this regard, the current paper presents data from a study that compared human raters' judgments of emotional expression between actual video clips of facial expressions and identical expressions rendered on a three-dimensional avatar using a performance-driven facial animation (PDFA) system developed at the University of Southern California Integrated Media Systems Center. PDFA offers a means for creating high-fidelity visual representations of human faces and bodies. This effort explores the feasibility of sensing and reproducing a range of facial expressions with a PDFA system. In order to test concordance of human ratings of emotional expression between video and avatar facial delivery, we first had facial model subjects observe stimuli that were designed to elicit naturalistic facial expressions. The emotional stimulus induction involved presenting text-based, still image, and video clips to subjects that were previously rated to induce facial expressions for the six universals2 of facial expression (happy, sad, fear, anger, disgust, and surprise), in addition to attentiveness, puzzlement and frustration. Videotapes of these induced facial expressions that best represented prototypic examples of the above emotional states and three-dimensional avatar animations of the same facial expressions were randomly presented to 38 human raters. The raters used open-end, forced choice and seven-point Likert-type scales to rate expression in terms of identification. The forced choice and seven-point ratings provided the most usable data to determine video/animation concordance and these data are presented. To support a clear understanding of this data, a website has been set up that will allow readers to view the video and facial animation clips to illustrate the assets and limitations of these types of facial expression-rendering methods (www. USCAvatars.com/MMVR). This methodological first step in our research program has served to provide valuable human user-centered feedback to support the iterative design and development of facial avatar characteristics for expression of emotional communication.

Frequency of appearance of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) in Graves' disease patients treated with propylthiouracil and the relationship between MPO-ANCA and clinical manifestations

OBJECTIVE

Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-positive vasculitis has been reported in patients with Graves' disease who were treated with propylthiouracil (PTU). The appearance of MPO-ANCA in these cases was suspected of being related to PTU because the titres of MPO-ANCA decreased when PTU was stopped. Nevertheless, there have been no studies on the temporal relationship between the appearance of MPO-ANCA and vasculitis during PTU therapy, or on the incidence of MPO-ANCA in untreated Graves' disease patients. Therefore, we sought to address these parameters in patients with Graves' disease.

PATIENTS

We investigated 102 untreated patients with hyperthyroidism due to Graves' disease for the presence of MPO-ANCA, and for the development vasculitis after starting PTU therapy. Twenty-nine of them were later excluded because of adverse effects of PTU or because the observation period was less than 3 months. The remaining 73 patients (55 women and 18 men), all of whom were examined for more than 3 months, were adopted as the subjects of the investigation. The median observation period was 23.6 months (range: 3-37 months).

MEASUREMENTS

MPO-ANCA was measured at intervals of 2-6 months.

RESULTS

Before treatment, the MPO-ANCA titres of all 102 untreated Graves' disease patients were within the reference range (below 10 U/ml). Three (4.1%) of the 73 patients were positive for MPO-ANCA at 13, 16 and 17 months, respectively, after the start of PTU therapy. In two of them, the MPO-ANCA titres transiently increased to 12.8 and 15.0 U/ml, respectively, despite continued PTU therapy, but no vasculitic disorders developed. In the third patient, the MPO-ANCA titre increased to 204 U/ml and she developed a higher fever, oral ulcers and polyarthralgia, but the symptoms resolved 2 weeks after stopping PTU therapy, and the MPO-ANCA titre decreased to 20.7 U/ml by 4 months after discontinuing PTU.

CONCLUSIONS

PTU therapy may be related to the appearance of MPO-ANCA, but MPO-ANCA does not appear to be closely related to vasculitis.

Association of autoimmune thyroid disease with microsatellite markers for the thyrotropin receptor gene and CTLA-4 in Japanese patients

In a previous study we identified a microsatellite marker near the thyrotropin receptor (TSHR) gene. Studies with this marker, TSHR-CA, revealed a significant association between autoimmune thyroid disease (AITD) in Japanese patients and one specific allele (allele 1; 180 base pair [bp]) of the microsatellite sequence. In addition, weak evidence for association of AITD with two alleles of the CTLA-4 gene was observed. In the present study, TSHR-CA has been mapped to approximately 600 kb of the TSHR gene using radiation hybrid mapping. TSHR-CA and another TSHR microsatellite marker, TSHR-AT, which is located in intron 2 of TSHR gene, were genotyped in a set of 349 unrelated Japanese AITD patients and 218 Japanese controls. The TSHR-AT marker showed association in this Japanese AITD population with a significant increase in allele 5 (294 bp; p < 0.05) and a significant decrease in allele 7 (298 bp; p < 0.05). The association of allele 5 of TSHR-AT was also significant in hypothyroid patients (thyrotropin-binding inhibitory immunoglobulin-positive [TBII+], P < 0.01; thyrotropin-binding inhibitory immunoglobulin-negative [TBII-], p < 0.05). The association of allele 7 of TSHR-AT were also significant for the hypothyroid TBII+ patients (p < 0.05). The CTLA-4 gene was also genotyped in this expanded set of Japanese AITD patients and controls. Association between AITD susceptibility and allele 2 (102 bp; p < 0.01) and allele 4 (106 bp; p < 0.01) were observed. These associations were also observed with GD patients (allele 2, p < 0.01; allele 4, p < 0.01). Associations with TSHR-CA were observed for Hashimoto's thyroiditis (HT) patients with respect to alleles 3 (179 bp; p < 0.05) and 5 (175 bp; p < 0.05) and with hypothyroid TBII- patients for allele 4 (177 bp; p < 0.05). The presence of specific alleles of TSHR-CA, TSHR-AT, and CTLA-4 contribute significant increase in risk of development of AITD. These results confirm and expand on our previous study suggesting that alleles of the TSHR and CTLA-4 genes, or genes near them contribute to AITD susceptibility and set the stage for future studies of interactions between these genes and AITD.

Sympathetic overactivity in the development of eyelid retraction in a patient with euthyroid Graves' disease evaluated by accommodation

It is known that measurement of accommodation is useful to evaluate the sympathetic activity of intraocular muscles. To find if sympathetic overactivity is involved in eyelid retraction in euthyroid Graves' disease, we measured accommodation in two patients with this disease, whose serum concentrations of free T3, free T4 and TSH were within reference ranges. Accommodation was measured with a computer-assisted infrared optometer with an iriscoder, and the results were expressed as the change in the eye's refractive power (in diopters) in response to the movement of a target beam. In patient 1, the accommodation amplitude was low, indicating sympathetic overactivity. This amplitude rose to near the reference range when timolol maleate drops were used, and the eyelid retraction disappeared when guanethidine drops were given. During the use of guanethidine drops, accommodation remained normal. In patient 2, who had normal accommodation, eyelid retraction did not change with guanethidine administration, but improved with intravenous methylprednisolone pulse therapy. These two cases suggested that even in euthyroid Graves' disease, eyelid retraction is caused by sympathetic overactivity, and pulse therapy with methylprednisolone may be effective for eyelid retraction when guanethidine drops are not effective.

Thyroid-stimulating antibody is related to Graves' ophthalmopathy, but thyrotropin-binding inhibitor immunoglobulin is related to hyperthyroidism in patients with Graves' disease

We investigated the relationship between thyroid function or ophthalmopathy of Graves' disease and thyrotropin receptor antibodies (TRAb) in 155 untreated patients with Graves' hyperthyroidism. All patients were examined by ophthalmologists, and underwent computed tomography of the orbit and measurement of serum free triiodothyronine (FT3), free thyroxine (FT4), thyrotropin-binding inhibitor immunoglobulin (TBII), and thyroid stimulating antibodies (TSAb). Patients were divided into three groups according to the presence of orbital fat increase (OFI) and extraocular muscle enlargement (EME): 57 patients without OFI and EMO formed the no Graves' ophthalmopathy (NGO) group; 55 patients with OFI but without EMO formed the OF group; 43 patients with EME with or without OFI formed the EM group. The FT3, FT4, and thyroid weight increased in the order of the EME, NGO, and OFI groups. TSAb increased in the order of the NGO, OFI, and EME groups, and TSAb was significantly greater in the EME and OFI than in the NGO group. TBII was not significantly different among the three groups, but was lower in EME than NGO. There was a significant positive correlation between TBII and FT3 or FT4 in all patients combined as well as in all three groups, but correlation between TSAb and FT3 or FT4 was very weak in all groups, and that between TSAb and FT3 was not significant in the EM group In the relationship between ophthalmopathy and TRAb, the sum of the scores of eyelid swelling, proptosis, and extraocular muscle enlargement was taken as a measure of the overall severity of the Graves' ophthalmopathy (GO). TSAb was significantly correlated with the GO score, but there was no correlation between TBII and GO scores. In conclusion, TSAb was correlated with ophthalmopathy but TBII was related to hyperthyroidism.

Thyroid function in wholly breast-feeding infants whose mothers take high doses of propylthiouracil

BACKGROUND

Propylthiouracil (PTU) might theoretically be preferred over methimazole (MMI) during breast-feeding because of its lower milk/serum concentration ratio (0.1 vs. 1.0). The problem is that Graves' disease often relapses during the postpartum period, and high doses of PTU are sometimes needed to control maternal hyperthyroidism) during breast-feeding. However, there are virtually no data on the effects of maternal PTU on thyroid status of infants whose mothers take more than 300 mg PTU daily and who are wholly breast-feeding.

OBJECTIVES

To investigate whether mothers can breast-feed without adverse effects on infants' thyroid status while taking 300 mg or more daily of PTU.

SUBJECTS AND DESIGN

Eleven infants who were wholly breast-fed while their mothers took PTU 300-750 mg daily for Graves' hyperthyroidism were included in this study. In one of the 11 infants, the mother also took iodine 6 mg daily for a limited period. Thyroid status in these infants was evaluated.

MEASUREMENTS

Free T4 (FT4), thyrotrophin (TSH), and TSH binding inhibiting antibody (TBIAb) concentrations were examined at least once in the age range 6 days to 9 months. Maternal blood was also examined for FT4 and TBIAb on the same day, or within a week, of the infants' blood tests. FT4, TSH and TBIAb concentrations at birth were examined, using cord blood, in cases where antithyroid drugs had been continued through delivery.

RESULTS

Three of the 11 infants had TSH concentrations higher than the normal range for adults. In one of the three infants, the TSH concentration, which was determined 19 weeks after birth, was just above the normal range. In the remaining two infants whose mothers had taken PTU through delivery, TSH concentrations, determined within 7 days after birth, were distinctly high, but they became normal while maternal PTU doses were the same as or higher than those at the initial examination. Maternal PTU doses or FT4 concentrations were not significantly correlated with infants' TSH concentrations.

CONCLUSION

Mothers can breast-feed while taking propylthiouracil at doses as high as 750 mg daily without adverse effects on thyroid status in their infants.

Molecular cloning and functional expression of a phospholipase D from cabbage (Brassica oleracea var. capitata)

We cloned and expressed a full-length cDNA encoding a phospholipase D of type alpha (PLDalpha) from cabbage. Analysis of the cDNA predicted an 812-amino-acid protein of 92.0 kDa. The deduced amino acid sequence of cabbage PLD has 83% and 80% identity with Arabidopsis PLDalpha and castor bean PLD, respectively. Expression of this cDNA clone in E. coli shows a functional PLD activity similar to that of the natural PLD.

TSH receptor antibody-associated thyroid dysfunction following subacute thyroiditis

OBJECTIVE

Autoimmunity plays an important role in the development of thyrotrophin (TSH) receptor antibodies and the pathogenesis of Graves' disease and Hashimoto's thyroiditis. On the other hand, subacute thyroiditis is a self-limited inflammatory disease of presumed viral aetiology. The aim of this study was to examine whether subacute thyroiditis triggers TSH receptor antibody-associated thyroid disorders.

PATIENTS

We reviewed 1,697 patients with subacute thyroiditis seen between 1985 and 1995.

DESIGN AND MEASUREMENTS

We measured antibodies which inhibit the TSH binding to the TSH receptor (TBIAb), thyroid stimulating antibodies (TSAb) and antibodies that block TSH action (TBAb). Other thyroid autoantibodies were also determined.

RESULTS

TBIAb became positive in 38 patients following subacute thyroiditis. Thyroid function after the development of TBIAb appeared to be influenced by the bioactivity of the antibody. Hyperthyroidism developed in the presence of TSAb, and so did hypothyroidism in the presence of TBAb, although 21 patients did not have thyroid dysfunction despite high titres of TBIAb. Fifteen out of 17 patients recovered from hyperthyroidism or hypothyroidism after the disappearance of TBIAb sometimes even without medication. TBIAb-positive patients had a high incidence of a family history of thyroid disease and positive anti-thyroid microsomal antibodies. An ophthalmopathy similar to Graves' disease was also observed in 3 patients.

CONCLUSIONS

Subacute thyroiditis may trigger autoreactive B cells to produce TSH receptor antibodies, resulting in TSH receptor antibody-associated thyroid dysfunction in some patients.

Elevated serum granulocyte colony-stimulating factor levels in patients with Graves' disease

OBJECTIVE

Agranulocytosis is a serious side effect of anti-thyroid drugs (ATD). Granulocyte colony-stimulating factor (G-CSF) is one of the cytokines that increase granulocyte number. The aim of this study was to examine the sequential variation of serum G-CSF levels in patients with Graves' disease before and after ATD therapy.

PATIENTS

Sixty-three patients with Graves' disease were studied before, during and after treatment with methimazole (MMI). Serum samples from 71 healthy subjects were used as controls.

DESIGN AND MEASUREMENTS

Serum levels of G-CSF were measured by a novel chemiluminescent enzyme immunoassay, which was sensitive enough to determine G-CSF levels in healthy subjects. Blood granulocyte counts, serum, thyroid hormone and TSH levels, and titres of thyroid autoantibodies were also measured.

RESULTS

Serum G-CSF levels in Graves' patients before and 2 weeks after MMI were significantly higher than in healthy subjects. There was a significant correlation between serum G-CSF levels and granulocyte counts in untreated patients with Graves' disease. Untreated patients with granulocyte counts less than 2 x 10(9)/I had significantly lower serum G-CSF levels as compared with other untreated patients. Serum G-CSF levels gradually decreased thereafter. No correlation was observed between serum G-CSF levels and serum thyroid hormone levels or titres of thyroid autoantibodies. After ATD treatment, no correlation was found between serum G-CSF levels and granulocytes counts. There was no significant correlation between the change of serum G-CSF levels and that of granulocyte counts before and after MMI treatment. Graves' patients with mild agranulocytosis had normal or elevated serum G-CSF levels.

CONCLUSIONS

Significantly elevated serum G-CSF levels were observed in patients with Graves' hyperthyroidism. During ATD therapy, deficiency of G-CSF was not identified as a cause of agranulocytosis in this study.

Effects of propylthiouracil and methimazole on fetal thyroid status in mothers with Graves' hyperthyroidism

Thionamide therapy is a mainstay of the treatment of hyperthyroidism complicated by pregnancy, but it can expose the fetus to hypothyroidism. In terms of fetal thyroid status, propylthiouracil (PTU) has been preferred over methimazole (MMI) based on experimental data on limited transplacental passage, and lower doses have been recommended. However, neither of these practices is supported by convincing clinical evidence. We compared the effect of maternal ingestion of PTU with that of MMI on fetal thyroid status using cord sera at delivery in 77 mothers with Graves' hyperthyroidism who were receiving thionamides and whose free T4 (FT4) levels were within the normal range. We also examined the dose effects on fetal thyroid status in these women. Thirty-four women were taking PTU (group P), and 43 were taking MMI (group M). Neither the mean fetal FT4 nor the mean fetal TSH level was significantly different between the two groups. No significant difference in the occurrence of low FT4 levels or high fetal TSH levels was found between group P and group M (low FT4, 6% vs. 7%; high TSH, 21% vs. 14%). Little relationship was observed between maternal doses and fetal thyroid status; in fact, when low doses of both PTU (100 mg daily or less) and MMI (10 mg daily or less) were administered, high TSH levels in the fetus were observed in 7 of the 34 fetuses (21%) and in 6 of the 43 fetuses (14%), respectively. Higher doses were associated with normal or low fetal TSH levels. These findings demonstrate that in terms of fetal hypothyroidism-inducing potential, there is little reason to choose PTU over MMI. Individualized, not uniformly low, doses of these drugs may prevent fetal hypothyroidism.

Sympathetic overactivity of intraocular muscles evaluated by accommodation in patients with hyperthyroidism

Sympathetic overactivity occurs in Graves' disease, but little is known about autonomic nervous function in the eyes of subjects with this disease. We examined this function of the intraocular muscles in 12 patients with hyperthyroid Graves' disease and 12 healthy controls. Pupil size, pupillary unrest, and accommodation were measured with a computer-assisted infrared optometer and pupillometer. The mean and the coefficient of variation of the areas of the pupils were used to express pupil size and the degree of pupillary unrest, respectively. Accommodation was measured with the target light beam moving slowly and steadily, or instantaneously, and the results are expressed as the change in the eye's refractive power in response to these movements. The mean pupil size of the patients was not different from that of the controls. Pupillary unrest in the patients was smaller than in the controls. Accommodation in the patients was lower than that of the controls. Five patients were examined again 3 months later when they became euthyroid; pupillary unrest and accommodation had improved in all five patients. There were no significant differences in the activity of sympathetic nerves governing intraocular muscles in patients with or without eyelid retraction. These results indicate that intraocular muscles are sympathetically overactive in patients with hyperthyroidism, and suggest that eyelid retraction is not caused by sympathetic overactivity alone, but by another factor or factors, in addition.

Maternal hypothyroidism during early pregnancy and intellectual development of the progeny

OBJECTIVE

To investigate whether maternal hypothyroidism before the onset of fetal thyroid function influences mental development of the offspring.

DESIGN

We examined IQs in children in whom the mothers had been hypothyroid during early pregnancy (group 1). The IQs were compared with those of siblings who were not exposed to maternal hypothyroidism during gestation (group 2).

PATIENTS

Group 1 consisted of eight children. Mothers were examined for thyroid status during the fifth to 10th gestational weeks and were found to have distinctly low thyroxine levels and high thyrotropin levels; the levels became normal after thyroxine supplementation by 13 to 28 weeks of gestation. Seven of the eight children had nine siblings who had not been exposed to maternal hypothyroidism during gestation (group 2). Ages at examination were 4 to 10 years in group 1 and 4 to 15 years in group 2.

RESULTS

All children in group 1 showed normal IQs. There was no significant difference in the mean IQ between the children in group 1 who had siblings (112 +/- 11) and their siblings in group 2 (106 +/- 8). Even the subject whose mother had had the lowest thyroxine level (free thyroxine, 2.3 pmol/L) had an IQ similar to that of his sibling.

CONCLUSION

These data provide evidence against the presence of adverse effects of maternal hypothyroidism during early pregnancy on the subsequent mental development of the offspring.

Comparison of the incidence of association of periodic paralysis and hyperthyroidism in Japan in 1957 and 1991

Periodic paralysis has been known to be associated with thyrotoxicosis in Japan. The incidence was 8.6% among male and 0.4% among female thyrotoxic patients according to a survey performed in the three major thyroid clinics in Japan in 1957. To determine the changes in the incidence during the intervening 34 years, the same type of survey was carried out again in 1991 at the same three major thyroid clinics previously involved. The incidence of paralysis in 1991 was 4.3% among male and 0.04% among female thyrotoxic patients, indicating more than a 40% decrease in the incidence. The possible cause of the decrease is related to the changes in food consumption, namely, to the fact that less carbohydrate and more potassium were taken in 1991 than in 1957.