Stabilized Radiation Pressure Acceleration and Neutron Generation in Ultrathin Deuterated Foils.

Premature relativistic transparency of ultrathin, laser-irradiated targets is recognized as an obstacle to achieving a stable radiation pressure acceleration in the "light sail" (LS) mode. Experimental data, corroborated by 2D PIC simulations, show that a few-nm thick overcoat surface layer of high Z material significantly improves ion bunching at high energies during the acceleration. This is diagnosed by simultaneous ion and neutron spectroscopy following irradiation of deuterated plastic targets. In particular, copious and directional neutron production (significantly larger than for other in-target schemes) arises, under optimal parameters, as a signature of plasma layer integrity during the acceleration.

Gli1+-PDL Cells Contribute to Alveolar Bone Homeostasis and Regeneration.

The periodontal ligament (PDL) contains mesenchymal stem cells (MSCs) that can differentiate into osteoblasts, cementoblasts, and fibroblasts. Nevertheless, the distribution and characteristics of these cells remain uncertain. Gli1, an essential hedgehog signaling transcription factor, functions in undifferentiated cells during embryogenesis. Therefore, in the present study, the differentiation ability of Gli1+ cells was examined using Gli1-CreERT2/ROSA26-loxP-stop-loxP-tdTomato (iGli1/Tomato) mice. In 4-wk-old iGli1/Tomato mice, Gli1/Tomato+ cells were only slightly detected in the PDL, around endomucin-expressing blood vessels. These cells had proliferated over time, localizing in the PDL as well as on the bone and cementum surfaces at day 28. However, in 8-wk-old iGli1/Tomato mice, Gli1/Tomato+ cells were quiescent, as most cells were not immunoreactive for Ki-67. These cells in 8-wk-old mice exhibited high colony-forming unit fibroblast activity and were capable of osteogenic, chondrogenic, and adipogenic differentiation in vitro. In addition, after transplantation of teeth of iGli1/Tomato mice into the hypodermis of wild-type mice, Tomato fluorescence indicating the progeny of Gli1+ cells was detected in the osteoblasts and osteocytes of the regenerated bone. These results demonstrate that Gli1+ cells in the PDL were MSCs and could contribute to the alveolar bone regeneration.

Impact of muscle volume loss on acute oral mucositis in patients undergoing concurrent chemoradiotherapy after oral cancer resection.

This study evaluated the association between skeletal muscle mass depletion and severe oral mucositis in patients undergoing concurrent chemoradiotherapy after oral cancer resection. Skeletal muscle mass was evaluated in 60 patients using the skeletal muscle index, which was based on skeletal muscle cross-sectional area (on computed tomography) at the level of the third lumbar vertebra. In accordance with the grading criteria of the Radiation Therapy Oncology Group, patients with a grade ≥3 were defined as having severe oral mucositis. Multivariate logistic regression analysis was used to evaluate independent risk factors for severe oral mucositis. Eleven patients (18.3%) were diagnosed with low skeletal muscle mass. Severe oral mucositis occurred in 17 (28.3%) patients, and the mean skeletal muscle index was 42.8 cm2/m2. A low skeletal muscle mass (hazard ratio 18.1; P=0.001) and a chemotherapy regimen consisting of 5-fluorouracil and cisplatin (versus cisplatin only) (hazard ratio 5.5; P=0.015) were independent risk factors for severe oral mucositis. Future prospective studies are warranted to identify effective pre- and perioperative exercises and nutrition programmes to increase low skeletal muscle mass and reduce the incidence of severe oral mucositis in patients undergoing concurrent chemoradiotherapy after oral cancer resection.

Immune complexome analysis reveals the presence of immune complexes and identifies disease-specific immune complex antigens in saliva samples from patients with Sjögren's syndrome.

Sjögren's syndrome (SS) is a chronic autoimmune disease that mainly damages the salivary and lacrimal glands. Immune complex (IC) formation triggers local inflammation through IC deposition and decreased antigen function. Some ICs can leak from the lesion and into the saliva, but no salivary ICs have been reported to date. We used immune complexome analysis to comprehensively identify antigens incorporated into IC (IC-antigens) in saliva samples from patients with SS (n = 9) or with xerostomia (n = 7). Neutrophil defensin 1 (67%), small proline-rich protein 2D (67%), myeloperoxidase (44%), neutrophil elastase (44%), cathepsin G (33%), nuclear mitotic apparatus 1 (33%) and phosphatidylinositol 4-phosphate 3-kinase C2 domain-containing subunit gamma (33%) were identified as new IC-antigens specifically and frequently detected in the saliva of SS patients. Of these, neutrophil defensin 1, myeloperoxidase, neutrophil elastase and cathepsin G are neutrophil intracellular proteins, which suggests that repeated destruction of neutrophils due to abnormal autoimmunity may be involved in the pathogenesis of SS. We also analyzed serum samples from three SS patients. There was little overlap of IC-antigens between two of the samples (fewer than 30% of the IC-antigens in the saliva samples), suggesting that many ICs are formed locally and independently of the circulation. In addition, we found that four SS-specific salivary antigens show sequence homology with several proteins of oral microbiomes but no antigen has homology with Epstein-Barr virus proteins. The homology between some IC-antigens and oral microbiome proteins may indicate the impact of oral infection on local autoimmunity through molecular mimicry theory.

Fibronectin plays a major role in hypoxia-induced lenvatinib resistance in hepatocellular carcinoma PLC/PRF/5 cells.

Resistance to lenvatinib mesylate (LEN), a systemic chemotherapy that can be administered orally, has been a major issue for treatment of hepatocellular carcinoma (HCC). Although HCC is the tumor that most exhibits intratumoral hypoxia, which has been shown to be involved in the development of treatment resistance, there are no reports of LEN resistance in HCC treatment under hypoxia. The purpose of our study was to elucidate the mechanism of treatment resistance to LEN under hypoxia using HCC cell lines. We confirmed LEN resistance under hypoxic conditions in HCC cell lines. There was a significant increase in the IC50 value of PLC/PRF/5 cells from 13.0±0.8 µM in normoxia to 21.3±1.1 µM in hypoxia, but in HepG2 cells, the increase was not significant. To elucidate the LEN resistance mechanism of PLC/PRF/5 cells under hypoxia, we performed microarray analysis and extracted genes that are thought to be related to this mechanism. Furthermore, in-silico analysis confirmed significant changes in the extracellular matrix, and among them, FN1 encoding fibronectin was determined as the hub of the gene cluster. The expression of fibronectin in PLC/PRF/5 cells examined with immunofluorescence staining was significantly elevated in and outside of cells under hypoxia, and tended to decrease when cells were exposed to LEN under normoxia. Furthermore, the fibronectin concentration in the culture solution of PLC/PRF/5 cells examined by ELISA was 2.3 times higher under hypoxia than under normoxia under LEN(-) conditions, and 1.6 times higher under hypoxia than under normoxia under LEN(+) conditions. It is assumed that in PLC/PRF/5 cells, fibronectin is probably suppressed as an indirect effect of LEN under normoxia, but transcription factors such as HIF-1α are induced under hypoxia, thus enhancing the production of fibronectin and attenuating the effect of LEN, resulting in drug resistance. This behavior of fibronectin with LEN exposure under hypoxia is probably specific to PLC/PRF/5 cells. Further studies should verify the combined effective inhibition of fibronectin and the MAPK pathway as a promising therapeutic strategy to enhance the value of LEN in HCC treatment.

M2 Phenotype Macrophages Colocalize with Schwann Cells in Human Dental Pulp.

Macrophages are immune cells with high plasticity that perform many functions related to tissue injury and repair. They are generally categorized as 2 functional phenotypes: M1 (proinflammatory) and M2 (anti-inflammatory and prohealing). To investigate the role of macrophages in human dental pulp, we examined the localization and distributional alterations of macrophages in healthy dental pulp as well as during the reparative process of pulp capping with mineral trioxide aggregate (MTA) and in cariously inflamed pulp of adult human teeth. We also quantified the populations of M1/M2 macrophages in healthy dental pulp by flow cytometric analysis. CD68+CD86+ cells (M1 phenotype) and CD68+CD163+ cells (M2 phenotype) were 2.11% ± 0.50% and 44.99% ± 2.22%, respectively, of 2.96% ± 0.41% CD68+ cells (pan-macrophages) in whole healthy dental pulp. Interestingly, M2 phenotype macrophages were associated with Schwann cells in healthy pulp, during mineralized bridge formation, and in pulp with carious infections in vivo. Furthermore, the M2 macrophages associated with Schwann cells expressed brain-derived neurotrophic factor (BDNF) under all in vivo conditions. Moreover, we found that plasma cells expressed BDNF. Coculture of Schwann cells isolated from human dental pulp and human monocytic cell line THP-1 showed that Schwann cells induced M2 phenotypic polarization of THP-1 cell-derived macrophages. The THP-1 macrophages that maintained contact with Schwann cells were stimulated, leading to elongation of their cell shape and expression of M2 phenotype marker CD163 in cocultures. In summary, we revealed the spatiotemporal localization of macrophages and potent induction of the M2 phenotype by Schwann cells in human dental pulp. M2 macrophages protect neural elements, whereas M1 cells promote neuronal destruction. Therefore, suppressing the neurodestructive M1 phenotype and maintaining the neuroprotective M2 phenotype of macrophages by Schwann cells may be critical for development of effective treatment strategies to maintain the viability of highly innervated dental pulp.

Weight of salivary gland ultrasonography compared to other items of the 2016 ACR/EULAR classification criteria for Primary Sjögren's syndrome.

OBJECTIVE: Major salivary gland ultrasonography (SGUS) is widely used for the diagnosis of primary Sjögren's syndrome (pSS). Our objective was to assess the contribution of SGUS compared to other items of the 2016 ACR/EULAR pSS classification criteria, based on expert opinion. METHODS: A secure web-based relational database was used by 24 experts from 14 countries to assess 512 realistic vignettes developed from data of patients with suspected pSS. Each vignette provided classification criteria items and information on history, clinical symptoms and SGUS findings. Each expert assessed 64 vignettes, and each vignette was assessed by 3 experts. A diagnosis of pSS was defined according to at least 2 of 3 experts. Validation was performed in the independent French DiapSS cohort of patients with suspected pSS. RESULTS: A criteria-based pSS diagnosis and SGUS findings were independently associated with an expert diagnosis of pSS (P < 0.001). The derived diagnostic weights of individual items in the 2016 ACR/EULAR criteria including SGUS were as follows: anti-SSA, 3; focus score ≥ 1, 3; SGUS score ≥ 2, 1; positive Schirmer's test, 1; dry mouth, 1; and salivary flow rate < 0.1 mL/min, 1. The corrected C statistic area under the curve for the new weighted score was 0.96. Adding SGUS improves the sensitivity from 90.2 % to 95.6% with a quite similar specificity 84.1% versus 82.6%. Results were similar in the DiapSS cohort: adding SGUS improves the sensitivity from 87% to 93%. CONCLUSION: SGUS had similar weight compared to minor items, and its addition improves the performance of the 2016 ACR/EULAR classification criteria.

Anti-citrullinated protein antibody titre as a predictor of abatacept treatment persistence in patients with rheumatoid arthritis: a prospective cohort study in Japan.

Objective: Successful rheumatoid arthritis (RA) outcome depends on treatment efficacy in the early stages of the disease and its sustainability. It is thus critical to identify factors predicting treatment persistence with biological agents, such as abatacept. We compared clinical profiles, including early changes in autoantibody titres at 3 months, between patients with RA demonstrating sustained persistence and those discontinuing abatacept treatment.Method: We prospectively enrolled 71 and 78 active RA patients treated with abatacept and tumour necrosis factor inhibitors (TNF-Is), respectively, who had previous disease-modifying anti-rheumatic drug) failure. Clinical characteristics were compared between non-continuation and continuation groups stratified according to abatacept or TNF-I persistence for at least 12 months from treatment initiation.Results: Significantly larger decreases in rheumatoid factor titre and anti-citrullinated protein autoantibody (ACPA) titre were observed in the continuation group of abatacept therapy at 3 months, and early reduction in ACPA titre remained a significant and independent predictor of sustained persistence with abatacept in multivariate analysis. In addition, we obtained the area under the receiver operator characteristics curve of 0.904 from a model including baseline ACPA titre and reduction of ACPA titre at 3 months. Sustained reduction of RA disease activity score at 12 months was significantly and independently associated with reduced ACPA titre at 3 months.Conclusions: Persistence with abatacept and sustained therapeutic response are associated with an early reduction in ACPA titre. Prediction of abatacept continuation and efficacy will facilitate the optimal design of therapy in the early stages of RA.

Impact of sarcopenia on postoperative surgical site infections in patients undergoing flap reconstruction for oral cancer.

Sarcopenia is characterized by progressive and generalized loss of skeletal muscle mass and strength. The aim of the study was to investigate the impact of skeletal muscle mass on surgical site infection (SSI) in flap reconstruction for defects after oral cancer resection. The subjects were a non-randomized, retrospective cohort of 106 patients who underwent this procedure after preoperative abdominal-lumbar computed tomography (CT). Cross-sectional areas (cm2) of skeletal muscles in the L3 region were measured by manual outlining on CT images. These areas were then normalized for height (cm2/m2) and defined as the skeletal muscle index (SMI). Recipient site SSI occurred in 28 patients (26.4%). Lower body mass index, haemoglobin and SMI were significantly related to recipient site SSI in univariate analysis (P<0. 05). In a multiple logistic regression model, lower SMI was a significant risk factor for recipient site SSI (odds ratio = 3.95 per 10 cm2/m2 decrease, P=0. 005). This result suggests that increasing skeletal muscle mass by exercise or nutrition before surgery may prevent recipient site SSI after resection of oral cancer and subsequent reconstruction.

Intratumoural immune cell landscape in germinoma reveals multipotent lineages and exhibits prognostic significance.

AIMS: Alterations in microenvironments are a hallmark of cancer, and these alterations in germinomas are of particular significance. Germinoma, the most common subtype of central nervous system germ cell tumours, often exhibits massive immune cell infiltration intermingled with tumour cells. The role of these immune cells in germinoma, however, remains unknown. METHODS: We investigated the cellular constituents of immune microenvironments and their clinical impacts on prognosis in 100 germinoma cases. RESULTS: Patients with germinomas lower in tumour cell content (i.e. higher immune cell infiltration) had a significantly longer progression-free survival time than those with higher tumour cell contents (P = 0.03). Transcriptome analyses and RNA in-situ hybridization indicated that infiltrating immune cells comprised a wide variety of cell types, including lymphocytes and myelocyte-lineage cells. High expression of CD4 was significantly associated with good prognosis, whereas elevated nitric oxide synthase 2 was associated with poor prognosis. PD1 (PDCD1) was expressed by immune cells present in most germinomas (93.8%), and PD-L1 (CD274) expression was found in tumour cells in the majority of germinomas examined (73.5%). CONCLUSIONS: The collective data strongly suggest that infiltrating immune cells play an important role in predicting treatment response. Further investigation should lead to additional categorization of germinoma to safely reduce treatment intensity depending on tumour/immune cell balance and to develop possible future immunotherapies.

Factors predictive of long-term mortality in lupus nephritis: a multicenter retrospective study of a Japanese cohort.

BACKGROUND: Lupus nephritis (LN) is a major determinant of mortality in systemic lupus erythematosus (SLE). Here we evaluated the association between complete renal response (CR) and mortality in LN. METHODS: We retrospectively analyzed the cases of 172 of 201 patients with LN for whom data on the therapeutic response at 6 and 12 months after induction therapy were available. The patients underwent a renal biopsy at Nagasaki University Hospital and community hospitals in Nagasaki between the years 1990 and 2016. We determined the CR rates at 6 and 12 months after induction therapy initiation and evaluated the predictive factors for CR and their relationship with mortality. We performed univariate and multivariable competing risks regression analyses to determine the factors predictive of CR. The patients' survival data were analyzed by the Kaplan-Meier method with a log-rank test. RESULTS: The median follow-up duration after renal biopsy was 120 months (interquartile range: 60.3-191.8 months). The 5-, 10-, 15- and 20-year survival rates of our cohort were 99.3, 94.6, 92.0 and 85.4%, respectively. During follow-up, nine patients (5.2%) died from cardiovascular events, infection, malignancy and other causes. The multivariate analysis revealed that the following factors were predictive of CR. At 6 months: male gender (odds ratio (OR) 0.23, 95% confidence interval (CI) 0.08-0.65, p = 0.0028), proteinuria (g/gCr) (OR 0.83, 95% CI 0.71-0.97, p = 0.0098) and index of activity (0-24) (OR 0.84, 95% CI 0.71-0.99, p = 0.0382). At 12 months: male gender (OR 0.25, 95% CI 0.09-0.67, p = 0.0043) and index of activity (0-24) (OR 0.82, 95% CI 0.69-0.98, p = 0.0236). The Kaplan-Meier analysis showed that compared to not achieving CR at 12 months, achieving CR at 12 months was significantly correlated with the survival rate (OR 0.18, 95% CI 0.04-0.92, p = 0.0339). CONCLUSIONS: Our results suggest that the survival rate of patients with LN is associated with the achievement of CR at 12 months after induction therapy, and that male gender and a higher index of activity (0-24) are the common predictive factors for failure to achieve CR at 6 and 12 months.

Complete renal response at 12 months after induction therapy is associated with renal relapse-free rate in lupus nephritis: a single-center, retrospective cohort study.

BACKGROUND: Lupus nephritis (LN) is a major risk factor for overall morbidity and mortality in systemic lupus erythematosus (SLE). METHODS: We retrospectively analyzed cases of proliferative and membranous LN patients who underwent a renal biopsy at our hospital in 1993-2016. We analyzed the association between complete renal response (CR) rates at 12 months after induction therapy and predictive factors for CR and their association with renal flares. RESULTS: Of the 95 cases analyzed, we were able to track the therapeutic responses of 81 patients at 12 months after their induction therapy. The median follow-up duration after renal biopsy was 51 months (interquartile range: 16.5-154.5 months). The Cox proportional hazards model showed that, compared to not attaining CR at 12 months, the attainment of CR at 12 months was correlated with being free from renal flares. The multivariate logistic analysis revealed that the predictive factors for CR at 12 months were the anti-La/SSB antibodies (U/ml) (odds ratio (OR) 1.22, 95% confidence interval (CI) 1.01-1.63, p = 0.0220), blood urea nitrogen (BUN) (OR 0.68, 95% CI 0.44-0.90, p = 0.00048) and serum ß2 microglobulin (MG) (OR 0.26, 95% CI 0.06-0.74, p = 0.00098) levels. CONCLUSIONS: Among LN patients, being free from renal flares was associated with attaining CR at 12 months after induction therapy. Anti-La/SSB antibodies were a positive predictive factor, and BUN and serum ß2MG levels were negative predictive factors of CR at 12 months.

QUANTITATIVE ESTIMATION OF EXPOSURE INHOMOGENEITY IN TERMS OF EYE LENS AND EXTREMITY MONITORING FOR RADIATION WORKERS IN THE NUCLEAR INDUSTRY.

To manage the equivalent doses for radiation workers, exposure inhomogeneity is an important factor in the decision-making process related to protection measures and additional monitoring. Our previous study proposed the methodology to evaluate the inhomogeneity of exposure quantitatively. In this study, we applied proposed method to five different types of actual exposure situations encountered in the nuclear industry. Two of them were conventionally characterized as homogeneous exposure, and the other three were conventionally characterized as inhomogeneous exposure. The evaluation of homogeneity exposure was conducted using Monte Carlo calculations with two simplified models, which were then verified with phantom experiments. Consequently, all of the evaluations reproduced the experimental results, implying that our proposed method would be applicable for actual work conditions in the nuclear industry. Furthermore, the two presumed homogeneous exposure situations were found to be rather inhomogeneous because of the contribution of positrons and the limited source region. The results also show that the worker's posture has an impact on the inhomogeneity rather than the energy of incident radiation in nuclear works. The investigation also implies that obtaining the information on the most probable posture of the exposed worker, as well as the existence of the weekly penetrating radiation such as ß± ray as a main source of exposure would be the key for more precise estimation.

Activation of Toll-like receptor 7 signaling in labial salivary glands of primary Sjögren's syndrome patients.

The aim of this study was to determine the expressions of Toll-like receptors (TLRs) 7-9 and type I interferon (IFN) signal in labial salivary glands (LSGs) and cultured salivary gland epithelial cells (SGECs) from primary Sjögren's syndrome (pSS) patients. We performed an immunohistochemistry analysis of LSGs from 11 patients with pSS as defined by American-European Consensus Group classification criteria and five healthy subjects. The pSS patients' SGECs were analyzed by immunofluorescence and western blotting. IFN-α expression was examined by immunosorbent assay and flow cytometry. Mononuclear cells (MNCs) from pSS patients' LSGs showed TLR-7-dominant expression. B cells, plasma cells and plasmacytoid dendritic cells (pDCs) co-expressed with TLR-7. Myeloid differentiation primary response gene 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF6) and interferon regulatory factor 7 (IRF7) co-expressed with the pDC marker CD303 in LSGs. Ducts from pSS patients dominantly expressed TLR-7, and TLR-7 in the ducts co-expressed with MyD88, TRAF6 and IRF7. Type I IFNs including IFN-α and IFN-ß were detected in MNCs and ducts in pSS patients' LSGs. Increased TRAF6 expression and the nuclear translocation of IRF7 in SGECs were detected by immunofluorescence following loxoribine (a TLR-7 ligand) stimulation despite IFN-ß pretreatment. Western blotting showed increased TRAF6 expression in SGECs following IFN-ß and loxoribine stimulation. Although no increase in IFN-α was detected in supernatant from stimulated SGECs, the IFN-α in supernatant from stimulated peripheral blood pDCs from pSS patients was significantly increased. Our findings suggest that TLR-7 is dominantly expressed in both MNCs and ducts with downstream signals for type I IFNs, indicating that TLR7-dominant innate immunity is related to the development of sialadenitis in pSS.

Routine Referral by Urologists Increase Opportunities for Corneal Donation.

BACKGROUND: The levels of corneal donation are insufficient to meet the demand for corneal transplantation in Japan. To overcome this problem, we started to routinely mention the possibility of corneal donation to the families of patients who died in our hospital's Urology Department in February 2008. In this study, we evaluated the effectiveness of this approach. METHODS: We retrospectively reviewed the medical records of the patients who died in the Department of Urology, St. Marianna University School of Medicine Hospital, and analyzed the patients' characteristics and information about corneal donation. RESULTS: In total, 211 patients died in our department between February 2008 and March 2017, and 155 patients were medically suitable corneal donors. We mentioned the possibility of corneal donation to 129 (83.2%) families, and 29 (18.7%) families agreed. Three families subsequently withdrew their consent. Finally, 26 (16.8%) of the families that were approached about corneal donation by urologists agreed to donate their relatives' corneas. Another 2 families voluntarily offered to donate their relatives' corneas. Thus, 28 (18.1%) of 155 medically suitable donors donated their corneas for transplantation. Twenty-six (92.8%) donors were 60 years or older and all donors were affected with malignant genitourinary tumors. Fifty-four (96.4%) corneas were successfully transplanted into recipients. CONCLUSIONS: Even elderly patients who die of solid carcinoma can be an important source of corneal donors. In this study, we showed that routine referral by urologists increased corneal donation. If this approach were adopted by other departments, it might further increase the number of corneal donations.

Detection of bone marrow-derived fibrocytes in human dental pulp repair.

AIM: To explore the expression profile of CD45+/pro-collagen I+ fibrocytes in intact dental pulps as well as during wound healing in adult dental pulp tissue. METHODOLOGY: A total of 16 healthy permanent teeth were obtained from young patients (18 to 25 years) undergoing orthodontic treatment. Routine pulp capping with mineral trioxide aggregate (MTA) was performed under local anaesthesia to induce a mineralized barrier at the exposed surface. Teeth were extracted from patients after 7, 14 and 35 days. Sections of the extracted teeth were prepared and stained for various markers using indirect immunofluorescence. Fibrocytes were counted, and the data were statistically evaluated using the Dunnett test. RESULTS: In uninflammed pulp tissue, a pro-collagen I-positive reaction was detected in odontoblasts, as well as in perivascular cells. Most of the CD45-positive cells were negative for pro-collagen I in normal pulp tissue, whereas CD45+/pro-collagen I+ fibrocytes were detected 7 days after injury. At day 14, fibrocytes were recognized under the fibrous matrix in contact with MTA and had infiltrated into regions of new capillary formation, where the fibrocytes were positively stained for vascular endothelial growth factor. By 35 days, fibrocytes were few, coincident with the formation of dentine bridges. The number of fibrocytes peaked 7 days post-injury and decreased at 14 days. CONCLUSIONS: The presence of fibrocytes in human pulp wound healing was observed. The spatiotemporal distribution of fibrocytes suggests that fibrocytes are involved in the early stages of pulp wound healing, specifically by contributing to new blood vessel formation.