ObjectiveThe malaria parasites remodel the host erythrocyte structure by exporting parasite proteins that interact with the membrane skeleton proteins of red blood cells (RBCs), facilitating their intracellular survival and pathogenicity. Skeleton-binding protein 1 (SBP1) is a conserved exported protein across Plasmodium species. In Plasmodium falciparum, SBP1 has been reported to interact with erythrocyte membrane skeleton proteins 4.1R and spectrin, while its contribution to erythrocyte remodeling and parasite virulence in Plasmodium berghei (Pb) remains unclear. This study aims to determine whether PbSBP1 associates with the host cytoskeletal protein 4.1R and to investigate its role in the remodeling of host RBCs and the pathogenicity of Plasmodium berghei. MethodsIn Plasmodium berghei, the relationship between PbSBP1 and the erythrocyte cytoskeletal protein 4.1R was examined using co-immunoprecipitation. A Pbsbp1 gene knockout mutant of Plasmodium berghei (Pbsbp1∆) was generated based on the principle of double crossover homologous recombination. The deformability of erythrocytes infected with Pbsbp1∆ parasites was assessed using microfluidic methods. Microchannels with an array of cylindrical pillars were used to detect modifications in infected RBC deformability. The infected RBCs were squashed between the rows and recovered between the columns and the transit velocity (μm/s) of infected RBCs travelling through the microchannel was recorded. The component of the erythrocyte membrane skeleton junctional complex, tropomodulin (TMOD), was fluorescently labeled, and the cytoskeletal network of infected erythrocytes was imaged using super-resolution stochastic optical reconstruction microscopy (STORM) to analyze ultrastructural changes in the cytoskeleton of wild-type (WT) and Pbsbp1∆-infected erythrocytes. Actin-based junctional complexes were displayed as individual clusters by the labeled TMOD in the STORM images, and the cluster densities and distances between adjacent clusters of infected RBCs were calculated. Additionally, rodent malaria models (BALB/c mice) and experimental cerebral malaria models (C57BL/6 mice) were employed to monitor the growth of Pbsbp1∆ and WT parasites during the intraerythrocytic stage and their capacity to induce cerebral malaria in mice. ResultsPbSBP1 may participate in the remodeling of infected erythrocytes through direct or indirect interaction with the erythrocyte cytoskeletal protein 4.1R. Microfluidic assays revealed that the deformability of erythrocytes infected with Pbsbp1∆ parasites was significantly enhanced compared to those infected with WT parasites. STORM imaging further demonstrated that the ultrastructure of the erythrocyte cytoskeleton in Pbsbp1∆-infected cells was altered relative to that in WT-infected erythrocytes. The distances between nearest neighbors of clusters had a tendency to increase while the cluster densities were decreased in Pbsbp1∆-infected RBCs compared to WT-infected RBCs. Subsequent phenotypic analysis indicated that the growth rate of Pbsbp1∆ parasites during the intraerythrocytic stage was significantly slower than that of WT parasites, and their ability to induce cerebral malaria in mice was also attenuated. These findings suggest that PbSBP1 is involved in the remodeling of the erythrocyte membrane skeleton, likely through its direct or indirect interaction with protein 4.1R, thereby regulating the deformability of infected erythrocytes and influencing the pathogenicity of the blood-stage parasites. ConclusionThis study establishes a role for PbSBP1 in host erythrocyte remodeling and parasite virulence, providing new research strategies for the prevention and treatment of malaria.

ObjectiveTo evaluate the clinical efficacy and economic value of the Jiangsu Traditional Chinese Medicine （TCM） Diagnosis and Treatment Protocol for Dominant Diseases （abbreviated as the Diagnosis and Treatment Protocol） in adult patients with non-severe community-acquired pneumonia （CAP） based on real-world clinical data. MethodsA retrospective real-world cohort study was conducted using electronic medical records of adult patients hospitalized for non-severe CAP from September 1st， 2023 to December 31st， 2024 across 10 TCM hospitals in Jiangsu province. Patients were classified into an exposure group and a non-exposure group based on whether they received Chinese herbal medicine （CHM） according to the Diagnosis and Treatment Protocol. The non-exposure group received only conventional western medicine， while the exposure group additionally received differentiated CHM for at least five consecutive days. Outcomes were compared between two patient groups， including cough resolution rate， sputum resolution rate （assessed by volume， color， and consistency）， incidence of abnormal C-reactive protein （CRP）， incidence of abnormal white blood cell （WBC） count， and radiographic resolution rate of pulmonary infiltrates on chest imaging. Multivariable logistic regression was performed to identify factors influencing clinical efficacy. Subgroup analyses were conducted according to age， gender， smoking status， history of hypertension， and pneumonia severity score （CURB-65）， and the efficacy of treatment for cough and sputum was analyzed within each subgroup. Cost-effectiveness analysis was conducted using cough resolution rate as the outcome measure， evaluating the pharmacoeconomics of the two groups. ResultsA total of 1688 patients were included with 1293 in the exposure group and 395 in the non-exposure group. Compared to the non-exposure group， the exposure group demonstrated significantly higher resolution rates of cough， sputum volume， color， and consistency， as well as a significantly lower incidence of abnormal CRP （P＜0.05）. No statistically significant difference was observed between the groups in terms of abnormal WBC count and radiographic resolution rate of pulmonary infiltrates （P＞0.05）. Logistic regression analysis showed that the cough resolution rate in the exposure group was 1.83 times that of the non-exposure group， while the probabilities of resolution in sputum volume， color， and consistency were 1.37， 2.09， and 1.56 times those of the non-exposure group， respectively （P＜0.05）. Subgroup analyses showed that the exposure group achieved significantly higher cough resolution rates across most subgroups except for populations with a CURB-65 score ≥2 or those with a history of hypertension （P＜0.05）. Specifically， among females， patients aged ≥18 and ＜65 years， non-smokers， those without hypertension， and those with a CURB-65 score of 0， the exposure group showed a higher cough resolution rate than the non-exposure group （P＜0.05）. From an economic perspective， total hospitalization cost， length of stay， antibiotic cost， and CHM cost all differed significantly between groups （P＜0.05）. The cost-effectiveness ratio （CER） was 10,788.80 CNY/case in the exposure group， while 22,513.80 CNY/case in the non-exposure group. This implies that， compared with the exposure group， the non-exposure group incurred an additional 17,302.27 CNY to achieve one case of cough resolution. When the willingness-to-pay threshold ranged from 0 to 50,000 CNY， the probability of economic advantage was consistently higher in the exposure group than in the non-exposure group. ConclusionOn the basis of conventional western medicine， the addition of CHM in accordance with the Diagnosis and Treatment Protocol can effectively improve clinical symptoms， reduce inflammatory markers， promote clinical recovery， and is more cost-effective in treating adults with non-severe CAP.

ObjectiveTo observe the real‑world effectiveness and economic outcomes of Weishi Qingjin Formula （苇石清金方， WQF） in the treatment of adult community‑acquired pneumonia （CAP） with phlegm‑heat obstructing the lung syndrome. MethodsBased on a multicenter， real-world retrospective cohort study， clinical data were collected from hospitalized adult patients diagnosed with non‑severe CAP and phlegm‑heat obstructing the lung syndrome in 10 traditional Chinese medicine （TCM） hospitals in Jiangsu province. Patients were divided into an exposure group （those who received oral WQF） and a non‑exposure group （those who did not）. The following outcomes were compared between the two groups before and after treatment， which were remission rates of clinical symptoms including cough， expectoration （sputum volume， color， consistency）， and chest pain， levels of inflammatory markers including C‑reactive protein （CRP） and white blood cell count （WBC）， and the rate of pulmonary inflammatory absorption on chest CT. Subgroup analyses were performed based on age， gender， smoking status， presence of hypertension， and the severity of community-acquired pneumonia （CURB‑65） score， comparing the two groups in terms of cough remission rate， chest pain remission rate， and chest CT absorption rate. For health economic evaluation， cost‑effectiveness analysis was used to calculate the cost‑effectiveness ratio （CER） and incremental cost‑effectiveness ratio （ICER）. Univariate sensitivity analysis and probabilistic sensitivity analysis were performed to test the robustness of the results. ResultsA total of 647 patients in the exposure group and 1491 patients in the non-exposure group were included in the final statistical analysis. There was no statistically significant difference in length of hospital stay， gender， marital status， smoking history， bronchoscopy history， and comorbidities between the groups （P＞0.05）， but age， CURB-65 score， and antibiotic use. The exposure group had significantly higher remission rates of cough and sputum consistency than the non-exposure group （P＜0.05）. After adjusting for confounders using propensity score matching and logistic regression， the cough remission rate in the exposure group was 1.49 times that of the non-exposure group （P＜0.01）. No significant difference was observed between groups in the reduction rates of CRP and WBC， and in the rate of pulmonary inflammatory absorption on chest CT （P＞0.05）. Subgroup analyses revealed that the cough remission rate in the exposure group was significantly better than that in the non-exposure group except for patients aged ≥65 years， smokers， hypertensive patients， those using other type antibiotics or not using antibiotics， and those with a CURB-65 score ≥1 （P＜0.05）. Among smokers， the chest pain remission rate in the exposure group was 4.38 times that of the non-exposure group （P＜0.01）. No significant difference in chest CT absorption rate was found between groups across subgroups of gender， age， hypertension status， or antibiotic type （P＞0.05）. In terms of economic evaluation， CER was 10,877.60 CNY/case in the exposure group and 16,773.10 CNY/case in the non-exposure group. Compared to the exposure group， the non-exposure group incurred an additional 15,034.26 CNY to achieve one case of cough resolution， indicating a more favorable cost-effectiveness profile. Probabilistic sensitivity analysis yielded results consistent with the cost-effectiveness analysis， confirming the robustness of the findings. ConclusionWQF demonstrates significant efficacy in improving cough symptoms in the treatment of adult CAP with phlegm-heat obstructing the lung syndrome， and also exhibits favorable economic benefits.

ObjectiveTo evaluate the clinical efficacy and economic value of the Jiangsu Traditional Chinese Medicine （TCM） Diagnosis and Treatment Protocol for Dominant Diseases （abbreviated as the Diagnosis and Treatment Protocol） in adult patients with non-severe community-acquired pneumonia （CAP） based on real-world clinical data. MethodsA retrospective real-world cohort study was conducted using electronic medical records of adult patients hospitalized for non-severe CAP from September 1st， 2023 to December 31st， 2024 across 10 TCM hospitals in Jiangsu province. Patients were classified into an exposure group and a non-exposure group based on whether they received Chinese herbal medicine （CHM） according to the Diagnosis and Treatment Protocol. The non-exposure group received only conventional western medicine， while the exposure group additionally received differentiated CHM for at least five consecutive days. Outcomes were compared between two patient groups， including cough resolution rate， sputum resolution rate （assessed by volume， color， and consistency）， incidence of abnormal C-reactive protein （CRP）， incidence of abnormal white blood cell （WBC） count， and radiographic resolution rate of pulmonary infiltrates on chest imaging. Multivariable logistic regression was performed to identify factors influencing clinical efficacy. Subgroup analyses were conducted according to age， gender， smoking status， history of hypertension， and pneumonia severity score （CURB-65）， and the efficacy of treatment for cough and sputum was analyzed within each subgroup. Cost-effectiveness analysis was conducted using cough resolution rate as the outcome measure， evaluating the pharmacoeconomics of the two groups. ResultsA total of 1688 patients were included with 1293 in the exposure group and 395 in the non-exposure group. Compared to the non-exposure group， the exposure group demonstrated significantly higher resolution rates of cough， sputum volume， color， and consistency， as well as a significantly lower incidence of abnormal CRP （P＜0.05）. No statistically significant difference was observed between the groups in terms of abnormal WBC count and radiographic resolution rate of pulmonary infiltrates （P＞0.05）. Logistic regression analysis showed that the cough resolution rate in the exposure group was 1.83 times that of the non-exposure group， while the probabilities of resolution in sputum volume， color， and consistency were 1.37， 2.09， and 1.56 times those of the non-exposure group， respectively （P＜0.05）. Subgroup analyses showed that the exposure group achieved significantly higher cough resolution rates across most subgroups except for populations with a CURB-65 score ≥2 or those with a history of hypertension （P＜0.05）. Specifically， among females， patients aged ≥18 and ＜65 years， non-smokers， those without hypertension， and those with a CURB-65 score of 0， the exposure group showed a higher cough resolution rate than the non-exposure group （P＜0.05）. From an economic perspective， total hospitalization cost， length of stay， antibiotic cost， and CHM cost all differed significantly between groups （P＜0.05）. The cost-effectiveness ratio （CER） was 10,788.80 CNY/case in the exposure group， while 22,513.80 CNY/case in the non-exposure group. This implies that， compared with the exposure group， the non-exposure group incurred an additional 17,302.27 CNY to achieve one case of cough resolution. When the willingness-to-pay threshold ranged from 0 to 50,000 CNY， the probability of economic advantage was consistently higher in the exposure group than in the non-exposure group. ConclusionOn the basis of conventional western medicine， the addition of CHM in accordance with the Diagnosis and Treatment Protocol can effectively improve clinical symptoms， reduce inflammatory markers， promote clinical recovery， and is more cost-effective in treating adults with non-severe CAP.

ObjectiveTo observe the real‑world effectiveness and economic outcomes of Weishi Qingjin Formula （苇石清金方， WQF） in the treatment of adult community‑acquired pneumonia （CAP） with phlegm‑heat obstructing the lung syndrome. MethodsBased on a multicenter， real-world retrospective cohort study， clinical data were collected from hospitalized adult patients diagnosed with non‑severe CAP and phlegm‑heat obstructing the lung syndrome in 10 traditional Chinese medicine （TCM） hospitals in Jiangsu province. Patients were divided into an exposure group （those who received oral WQF） and a non‑exposure group （those who did not）. The following outcomes were compared between the two groups before and after treatment， which were remission rates of clinical symptoms including cough， expectoration （sputum volume， color， consistency）， and chest pain， levels of inflammatory markers including C‑reactive protein （CRP） and white blood cell count （WBC）， and the rate of pulmonary inflammatory absorption on chest CT. Subgroup analyses were performed based on age， gender， smoking status， presence of hypertension， and the severity of community-acquired pneumonia （CURB‑65） score， comparing the two groups in terms of cough remission rate， chest pain remission rate， and chest CT absorption rate. For health economic evaluation， cost‑effectiveness analysis was used to calculate the cost‑effectiveness ratio （CER） and incremental cost‑effectiveness ratio （ICER）. Univariate sensitivity analysis and probabilistic sensitivity analysis were performed to test the robustness of the results. ResultsA total of 647 patients in the exposure group and 1491 patients in the non-exposure group were included in the final statistical analysis. There was no statistically significant difference in length of hospital stay， gender， marital status， smoking history， bronchoscopy history， and comorbidities between the groups （P＞0.05）， but age， CURB-65 score， and antibiotic use. The exposure group had significantly higher remission rates of cough and sputum consistency than the non-exposure group （P＜0.05）. After adjusting for confounders using propensity score matching and logistic regression， the cough remission rate in the exposure group was 1.49 times that of the non-exposure group （P＜0.01）. No significant difference was observed between groups in the reduction rates of CRP and WBC， and in the rate of pulmonary inflammatory absorption on chest CT （P＞0.05）. Subgroup analyses revealed that the cough remission rate in the exposure group was significantly better than that in the non-exposure group except for patients aged ≥65 years， smokers， hypertensive patients， those using other type antibiotics or not using antibiotics， and those with a CURB-65 score ≥1 （P＜0.05）. Among smokers， the chest pain remission rate in the exposure group was 4.38 times that of the non-exposure group （P＜0.01）. No significant difference in chest CT absorption rate was found between groups across subgroups of gender， age， hypertension status， or antibiotic type （P＞0.05）. In terms of economic evaluation， CER was 10,877.60 CNY/case in the exposure group and 16,773.10 CNY/case in the non-exposure group. Compared to the exposure group， the non-exposure group incurred an additional 15,034.26 CNY to achieve one case of cough resolution， indicating a more favorable cost-effectiveness profile. Probabilistic sensitivity analysis yielded results consistent with the cost-effectiveness analysis， confirming the robustness of the findings. ConclusionWQF demonstrates significant efficacy in improving cough symptoms in the treatment of adult CAP with phlegm-heat obstructing the lung syndrome， and also exhibits favorable economic benefits.

Background: Malignant pleural effusion (MPE), a common complication of advanced cancers, is associated with poor prognosis and reduced quality of life. Although host–tumor interactions are known to drive MPE development, the associated immune dynamics during disease progression remain unclear. Using a Lewis lung carcinoma-induced MPE model in C57BL/6JNidfc mice, we systematically evaluated general parameters and immune cell changes at two-day intervals throughout disease progression. Results: The day of Lewis lung carcinoma cell injection into the pleural space was designated as day 0. By day 10 post-injection (p.i.), MPE-bearing mice exhibited ~ 10% body weight loss, marking the experimental endpoint. Pleural tumor mass and pleural effusion volume were minimal up to day 4 p.i. but increased sharply from day 6 onward.CD45⁺ immune cell counts rose over time, and days 6, 8, and 10 p.i. marked key stages of MPE progression. On day 6, B cells, T cells, and natural killer cells, but not macrophages and neutrophils, increased significantly compared to earlier timepoints. By day 8, all immune cell subsets except T cells exceeded day 6 levels, and at day 10, natural killer cell numbers declined while others continued to increase. Besides, the numbers of CD8⁺ T cells, Th1 cells, regulatory T cells, and M2 macrophages progressively increased from day 6 to 10. Based on these data, days 6 and 10 were defined as early and advanced MPE stages, respectively, with distinct immune phenotypes. In advanced MPE, CD8⁺ T cells displayed reduced IFN-γ, TNF-α, Granzyme B, Perforin, FasL, and Ki-67, but upregulated PD-1 and CTLA-4 relative to early stage. Similarly, Th1 cells showed decreased IFN-γ, TNF-α, and IL-2 production along with reduced Ki-67 expression. Advanced-stage M2 macrophages exhibited lower MHC-II levels and impaired phagocytosis, but higher PD-L1 and IL-10 production, while neutrophils showed reduced TNF-α release and phagocytic activity. Conclusions Our findings characterize the temporal immune dynamics associated with MPE progression in a mouse model, revealing a transition from an early immunostimulatory state to a late immunosuppressive state. This study enhances our understanding of MPE immunopathogenesis and provides a foundation for developing precise, stagespecific therapeutic strategies.

Background::Computer-aided detection (CAD) software has been introduced to automatically interpret digital chest X-rays. This study aimed to evaluate the performance of CAD software (JF CXR-1 v3.0, which was developed by a domestic Hi-tech enterprise) in tuberculosis (TB) case finding in China.Methods::In 2019, we conducted an internal evaluation of the performance of JF CXR-1 v3.0 by reading standard images annotated by a panel of experts. In 2020, using the reading results of chest X-rays by a panel of experts as the reference standard, we conducted an on-site prospective study to evaluate the performance of JF CXR-1 v3.0 and local radiologists in TB case finding in 13 township health centers in Zhongmu County, Henan Province.Results::Internal assessment results based on 277 standard images showed that JF CXR-1 v3.0 had a sensitivity of 85.94% (95% confidence interval [CI]: 77.42%, 94.45%) and a specificity of 74.65% (95% CI: 68.81%, 80.49%) to distinguish active TB from other imaging conditions. In the on-site evaluation phase, images from 3705 outpatients who underwent chest X-ray detection were read by JF CXR-1 v3.0 and local radiologists in parallel. The imaging diagnosis of local radiologists for active TB had a sensitivity of 32.89% (95% CI: 22.33%, 43.46%) and a specificity of 99.28% (95% CI: 99.01%, 99.56%), while JF CXR-1 v3.0 showed a significantly higher sensitivity of 92.11% (95% CI: 86.04%, 98.17%) ( p < 0.05) and maintained high specificity at 94.54% (95% CI: 93.81%, 95.28%). Conclusions::CAD software could play a positive role in improving the TB case finding capability of township health centers.

Objective:Exploring the role and mechanism of CHMP4C in regulating necroptosis during gastric can-cer development and progression.Method:The expression of CHMP4C in pan-cancer was analyzed by bioinformatics methods,and the expression of CHMP4C was detected in human normal gastric epithelial cells and GC cell lines by RT-qPCR and Western blot.Overexpression or knockdown of CHMP4C was performed in GC cell lines,and the effects of CHMP4C on the growth and proliferation of GC cells were detected using CCK-8 and clone formation assays.The CCK-8 experiment and Hoechst/PI double staining experiment were used to detect the changes in GC cell mortality and PI positive cell ratio after treatment with the necroptsis inducer TSZ or inhibitor necrostatin-1(Nec-1).Western blot assay was used to detect the protein and phosphorylation levels of RIPK1,RIPK3,and MLKL in GC cells.Result:CHMP4C was upregulated in GC tissues and cells.The CCK-8 and clone formation experiments showed that overex-pression of CHMP4C significantly improved the proliferation ability and colony formation efficiency of GC cells,while knockdown of CHMP4C significantly weakened GC cells.Moreover,the results of CCK-8 and Hoechst 33342/PI double staining experiments showed that upregulated CHMP4C could inhibit TSZ induced GC cell death;Nec-1 can reverse the decrease in GC cell viability caused by CHMP4C knockdown.Western blot experiment showed that the levels of p-RIPK1,p-RIPK3,and p-MLKL were significantly decreased in overexpressing cells,while they were increased in knockdown cells.After treatment with Nec-1,the expression levels of these three proteins decreased in knockdown cells.Conclusion:CHMP4C may promote GC progression by negatively regulating necroptosis through inhibiting the phosphorylation of the RIPK1/RIPK3/MLKL signaling pathway,suggesting that it is expected to be a potential target for GC therapy.

Objective To analyze the serum metabolomic changes of preterm infants with bronchopulmonary dysplasia(BPD)at postmenstrual age(PMA)36 weeks,screen potential biomarkers and associated metabolic pathways,and assess their relationship with short-term respiratory outcomes.Methods A retrospective case-control study was conducted.Infants with gestational age 28-32 weeks admitted to the Children's Hospital Affiliated to Zhengzhou University from January to December 2024 were included.Twenty infants with BPD and 20 gestational age-,birth weight-,and sex-matched non-BPD preterm infants were included.Serum collected at PMA 36 weeks was subjected to untargeted metabolomics analysis,and associations with short-term respiratory outcomes were analyzed.Results Thirteen potential biomarkers distinguishing BPD were identified(area under the curve>0.75,P<0.05).Eight biomarkers—including terephthalic acid,phosphatidylinositol,fumarate,and lysophosphatidic acid—were significantly upregulated(FC≥1.5),while five biomarkers,such as 7α-hydroxy-3-oxo-4-cholestenoate ester and phosphatidylcholine,were significantly downregulated(FC≤1/1.5).Pathway analysis indicated five pathways associated with BPD,including glycerophospholipid metabolism and phenylalanine metabolism.Dysregulation of glycerophospholipid and bile acid metabolism may affect adverse short-term respiratory outcomes in infants with BPD.Conclusions The 13 significantly different metabolites may serve as biomarkers for the diagnosis of BPD.Glycerophospholipid metabolism is associated with the occurrence of BPD and with adverse short-term respiratory outcomes.

Objective:To investigate the immuno-inflammatory regulatory effects of the Qing Gan San Jie Xiao Ying Formula(QGSJXYF)on Hashimoto's thyroiditis(HT)by modulating thyroid cell-derived exosomes to provide experi-mental evidence for its immunomodulatory mechanisms.Methods:Nthy-ori-3-1 thyroid cells were treated with QGSJXYF-medicated serum,with untreated cells serving as controls.Exosomes from both groups were extracted and analyzed using nanoparticle tracking analysis(NTA),transmission electron microscopy(TEM),and Western blot to assess concentration,size distribution,morphology,and the expression of characteristic exosomal markers.An inflammatory model of human T lymphocytes(H9)was established and co-incubated with normal exosomes(EXO-C group)or QGSJXYF-treated exosomes(EXO-T group).The levels of inflammatory cytokines in H9 cells were measured using Western blot(WB)and ELISA.Results:Exosome characterization showed that the particle concentration of Nthy-ori-3-1 cell-derived exosomes in both the control and QGSJXYF groups ranged from 1×109 to 1×1011/mL,with particle diameters between 80～300 nm.The exosomes exhibited a typical spherical or cup-shaped morphology with positive expression of TSG101,CD63,and HSP70.Compared with the inflammation model group and the EXO-C group,the EXO-T group significantly reduced the intracellular expression of IL-17A protein in H9 cells(P<0.05)and suppressed IL-17 and IL-6 levels in the cell supernatant(P<0.01).Conclusion:QGSJXYF may exert its anti-inflammatory and thyroid-protective effects by modulating the functional state of thyroid cell-derived exosomes,regulating the inflamma-tory microenvironment,and inhibiting the expression of inflammatory cytokines associated with Hashimoto's thyroiditis.