Epidemiological link between wheat allergy and exposure to hydrolyzed wheat protein in facial soap

BACKGROUND

Recent studies have highlighted the importance of extra-intestinal routes of sensitization to food-related allergens as the cause of epidemics of food allergy. Instances of Japanese women developing food allergy to wheat after exposure to hydrolyzed wheat protein (HWP) present in facial soap have been reported. However, the epidemiologic impact of these ingredients as a cause of food allergy has not been well studied.

METHODS

To clarify the epidemiological relationship between food allergy to wheat and contact exposure to HWP, a case-control study of Japanese women aged 20-54 years with self-reported wheat allergy (WA) (cases, n = 157) and age-matched control subjects without WA (controls, n = 449) was performed using a large-scale Web-based research panel. Subjects answered a Web-based questionnaire regarding the use of skin and hair care products, as well as other possible risk factors.

RESULTS

Current use of an HWP-containing facial soap (Cha no Shizuku; Yuka) was significantly associated with an increased risk of WA (adjusted odds ratio, 2.6; 95% confidence interval, 1.2-5.7; frequencies of current use in cases and controls; 11% and 6%, respectively). Use of Cha no Shizuku was more common in subjects with more recent-onset WA, implying that this soap may have contributed to the recent epidemic of WA.

CONCLUSIONS

An epidemiological relationship between WA and contact exposure to HWP has been documented. This study implicates a possible role of contact exposure to food-derived protein hydrolysates as a risk factor for the development of food allergy manifesting itself as anaphylaxis.

Mesenchymal stem/progenitor cell isolation from tooth extraction sockets

Bone marrow-derived mesenchymal stem/progenitor cells (BMSCs) are commonly used in regeneration therapy. The current primary source of BMSCs is the iliac crest; however, the procedure is associated with various burdens on the patient, including the risk of pain and infection. Hence, the possibility to collect BMSCs from other, more accessible, sources would be an attractive approach. It is well known that stem cells migrate from surrounding tissues and play important roles in wound healing. We thus hypothesized that stem/progenitor cells could be isolated from granulation tissue in the dental socket, and we subsequently collected granulation tissue from dog dental socket 3 d after tooth extraction. After enzyme digestion of the collected tissue, the cells forming colonies constituted the dental socket-derived stem/progenitor cells (dDSCs). Next, dDSCs were compared with dog BMSCs (dBMSCs) for phenotype characterization. A flow cytometric analysis showed that dDSCs were positive for CD44, CD90, and CD271 but negative for CD34 and CD45, similar to dBMSCs. dDSCs also exhibited osteogenic, adipogenic, and chondrogenic differentiation ability, similar to dBMSCs, with a higher capacity for colony formation, proliferation, and motility than dBMSCs. In addition, an in vivo ectopic bone formation assay showed that dDSCs and dBMSCs both induced hard tissue formation, although only dDSCs formed a fibrous tissue-like structure connected to the newly formed bone. Finally, we tested the ability of dDSCs to regenerate periodontal tissue in a one-wall defect model. The defects in the dDSC-transplanted group (β-TCP/PGA/dDSCs) were regenerated with cementum-like and periodontal ligament-like tissues and alveolar bone, whereas only bony tissue was observed in the control group (β-TCP/PGA). In conclusion, we identified and characterized a population of stem/progenitor cells in granulation tissue obtained from the dental socket that exhibited several characteristics similar to those of BMSCs. Dental sockets could therefore be a novel source for isolating stem/progenitor cells from bone.

Gingivae contain neural-crest- and mesoderm-derived mesenchymal stem cells

Gingivae represent a unique soft tissue that serves as a biological barrier to cover the oral cavity side of the maxilla and mandible. Recently, the gingivae were identified as containing mesenchymal stem cells (GMSCs). However, it is unknown whether the GMSCs are derived from cranial neural crest cells (CNCC) or the mesoderm. In this study, we show that around 90% of GMSCs are derived from CNCC and 10% from the mesoderm. In comparison with mesoderm MSCs (M-GMSCs), CNCC-derived GMSCs (N-GMSCs) show an elevated capacity to differentiate into neural cells and chondrocytes and induce activated T-cell apoptosis in vitro. When transplanted into mice with dextran sulfate sodium (DSS)-induced colitis, N-GMSCs showed superior effects in ameliorating inflammatory-related disease phenotype in comparison with the M-GMSC treatment group. Mechanistically, the increased immunomodulatory effect of N-GMSCs is associated with up-regulated expression of FAS ligand (FASL), a transmembrane protein that plays an important role in MSC-based immunomodulation. In summary, our study indicates that the gingivae contain both neural-crest- and mesoderm-derived MSCs with distinctive stem cell properties.

Immune therapeutic potential of stem cells from human supernumerary teeth

Discoveries of immunomodulatory functions in mesenchymal stem cells (MSCs) have suggested that they might have therapeutic utility in treating immune diseases. Recently, a novel MSC population was identified from dental pulp of human supernumerary teeth, and its multipotency characterized. Herein, we first examined the in vitro and in vivo immunomodulatory functions of human supernumerary tooth-derived stem cells (SNTSCs). SNTSCs suppressed not only the viability of T-cells, but also the differentiation of interleukin 17 (IL-17)-secreting helper T (Th17)-cells in in vitro co-culture experiments. In addition, systemic SNTSC transplantation ameliorated the shortened lifespan and elevated serum autoantibodies and nephritis-like renal dysfunction in systemic lupus erythematosus (SLE) model MRL/lpr mice. SNTSC transplantation also suppressed in vivo increased levels of peripheral Th17 cells and IL-17, as well as ex vivo differentiation of Th17 cells in MRL/lpr mice. Adoptive transfer experiments demonstrated that SNTSC-transplanted MRL/lpr mouse-derived T-cell-adopted immunocompromised mice showed a longer lifespan in comparison with non-transplanted MRL/lpr mouse-derived T-cell-adopted immunocompromised mice, indicating that SNTSC transplantation suppresses the hyper-immune condition of MRL/lpr mice through suppressing T-cells. Analysis of these data suggests that SNTSCs are a promising MSC source for cell-based therapy for immune diseases such as SLE.

The prevalence of rhinitis and its association with smoking and obesity in a nationwide survey of Japanese adults

BACKGROUND

Rhinitis is a common disease, and its prevalence is increasing worldwide. Several studies have provided evidence of a strong association between asthma and rhinitis. Although smoking and obesity have been extensively analyzed as risk factors of asthma, associations with rhinitis are less clear.

OBJECTIVE

The aims of our study were (i) to evaluate the prevalence of rhinitis using the European Community Respiratory Health Survey (ECRHS) questionnaire in Japanese adults and (ii) to evaluate the associations of smoking and body mass index (BMI) with rhinitis.

METHODS

Following our study conducted in 2006-2007 to determine the prevalence of asthma using the ECRHS questionnaire, our present analysis evaluates the prevalence of rhinitis and its association with smoking and BMI in Japanese adults 20-79 years of age (N = 22819). We classified the subjects (20-44 or 45-79 years) into four groups as having (i) neither rhinitis nor asthma; (ii) rhinitis without asthma; (iii) asthma without rhinitis; or (iv) rhinitis with asthma. We then evaluated associations with smoking and BMI in each group.

RESULTS

The overall age-adjusted prevalence of rhinitis was 35.1% in men and 39.3% in women. A higher prevalence was observed in the younger population than in the older population. Active smoking and obesity were positively associated with asthma without rhinitis. In contrast, particularly in the 20- to 44-year age-group, active smoking and obesity were negatively associated with rhinitis without asthma.

CONCLUSION

The results of the present study suggest that smoking and obesity may have different effects on the development of rhinitis and asthma.

Three-dimensional distribution of articular cartilage thickness in the elderly talus and calcaneus analyzing the subchondral bone plate density

OBJECTIVE

To unveil the three-dimensional (3D) distribution of talocrural and posterior subtalar articular cartilage thickness in the elderly cadavers using 3D computed tomography (CT) and a 3D-digitizer and to evaluate the relationship between subchondral bone plate density and the overlying cartilage thickness.

DESIGN

Sixteen tali and 16 calcanei from eight cadavers were scanned with 3D-CT to create bone surface models, and with a 3D-digitizer to make cartilage surface models. These two surface models were merged using surface registration method. Articular cartilage thickness was evaluated as the distance between the two models, and the distribution was mapped. The anatomic cartilage thickness of five tali and five calcanei was compared with the distance between the cartilage and bone surface models to calculate optimum threshold for extracting the subchondral bone plate. Generalized estimating equations were used for comparison and measurement errors. Canonical correlation analysis was performed to determine the strength of association between subchondral bone plate threshold and cartilage thickness.

RESULTS

The talar-subtalar articular cartilage tended to be the thickest of the three joints. In the talocrural joint, the anterior region was the thinnest, and increasing cartilage thickness was seen toward the posterior. In the talar-subtalar joint, the central region was the thickest. Mean measurement errors were 0.059±0.066 mm, 0.038±0.040 mm, and 0.018±0.065 mm in the talocrural, talar-subtalar, and calcaneal-subtalar joints, respectively. The canonical correlation coefficient was 0.995 (P<0.001).

CONCLUSIONS

The articular cartilage thickness was distributed in the elderly hindfoot. The subchondral bone plate density was significantly correlated with the anatomic cartilage thickness.

Strong suppression of the Kosterlitz-Thouless transition in a 4He film under high pressure

We have found that the surface specularity for 3He quasiparticle scattering is closely related to the superfluidity and the Kosterlitz-Thouless (KT) transition of 4He film adsorbed on the surface. The specularity is determined by measurements of the transverse acoustic impedance of bulk liquid 3He. The unique point of our system is that we can control the correlation among 4He atoms in the film by changing the pressure of the bulk 3He. The observed KT transition temperature is significantly suppressed by increasing the pressure, which suggests a strong correlation effect on KT transition.

Basic fibroblast growth factor inhibits osteogenic differentiation of stem cells from human exfoliated deciduous teeth through ERK signaling

OBJECTIVE

Stem cells from human exfoliated deciduous teeth (SHED) are a unique postnatal stem cell population capable of regenerating mineralized tissue and treating immune disorders. However, the mechanism that controls SHED differentiation is not fully understood. Here, we showed that basic fibroblast growth factor (bFGF) treatment attenuated SHED-mediated mineralized tissue regeneration through activation of the extracellular signal-regulated kinase (ERK) 1/2 pathway.

MATERIAL AND METHOD

The level of mineralized nodule formation was assessed by alizarin red staining. Expression levels of osteogenic genes, osteocalcin and runt-related transcription factor 2, were examined by RT-PCR. Subcutaneous implantation approach was used to assess in vivo bone formation. Downstream signaling pathways of bFGF were examined by Western blotting.

RESULT

Activation of ERK1/2 signaling by bFGF treatment inhibited WNT/β-catenin pathway, leading to osteogenic deficiency of SHED. ERK1/2 inhibitor treatment rescued bFGF-induced osteogenic differentiation deficiency.

CONCLUSION

These data suggest that bFGF inhibits osteogenic differentiation of SHED via ERK1/2 pathway. Blockade ERK1/2 signaling by small molecular inhibitor treatment improves bone formation of SHED after bFGF treatment.

A massive basal cell adenocarcinoma of the palatal minor salivary gland that progressed into the pterygopalatine fossa

Basal cell adenocarcinoma (BCAC) is a rare malignant neoplasm in the salivary glands and BCAC of the minor salivary glands is exceedingly rare. Only nine cases of palatal BCACs of the minor salivary gland have been reported. BCAC is a low-grade malignant tumour which shares many histologic characteristics with basal cell adenoma. Histological differentiation between the two is difficult and they are often discriminated only by invasion of local structures or by perineural or vascular invasive figures. The authors describe the case of a 69-year-old man with a massive BCAC of a palatal minor salivary gland that progressed into the nasal cavity and pterygopalatine fossa and was treated by a subtotal maxillectomy. This is a highly locally advanced case which required a wider surgical excision range than other previously reported BCAC cases of the palatal minor salivary glands. In this case, the proper diagnosis could not be made by local biopsy alone. It should be kept in mind that it may be difficult to distinguish BCAC from basal cell adenoma by microscopic examination of biopsy specimens alone.

Obesity and aspirin intolerance are risk factors for difficult-to-treat asthma in Japanese non-atopic women

BACKGROUND

Asthma is a clinical syndrome characterized by variabilities in disease expression and severity. The pathophysiological mechanism underlying anti-asthma treatment resistance is also assumed to be different between disease phenotypes.

OBJECTIVE

To elucidate the effect of gender and atopic phenotype on the relationship between clinical factors and the risk of treatment resistance.

METHODS

We compared outpatients with difficult-to-treat asthma (DTA; n = 486) in a tertiary hospital for allergic diseases in central Japan with those with controlled severe asthma (n = 621) with respect to clinical factors including body mass index (BMI) and aspirin intolerance using multivariate logistic regression analysis stratified by gender and atopic phenotype.

RESULTS

When analysis was performed on the entire study populations, obesity (BMI ≥ 30 kg/m(2); adjusted odds ratio (OR) 1.92; 95% confidence interval (95% CI: 1.07-3.43) and aspirin intolerance (OR: 2.56, 95% CI: 1.44-4.57) were found to be the significant risk factors for DTA. However, after the stratification by gender and atopic phenotype, the association between obesity and DTA was significant only in women (OR: 2.76, 95% CI: 1.31-5.78), but not in men (OR: 1.03, 95% CI: 0.38-2.81), and only in non-atopics (OR: 4.03, 95% CI: 1.15-14.08), but not in atopics (OR: 1.54, 95% CI: 0.79-3.02). The similar gender and phenotypic differences were also observed in the association between aspirin intolerance and DTA: namely, the association was significant only in women (OR: 3.96, 95% CI: 1.84-8.50), but not in men (OR: 1.19, 95% CI: 0.46-3.05); and only in non-atopics (OR: 5.49, 95% CI: 1.98-15.19), but not in atopics (OR: 1.39, 95% CI: 0.65-2.98).

CONCLUSIONS AND CLINICAL RELEVANCE

Significant associations of obesity and aspirin intolerance with DTA were observed only in women and in non-atopics. These findings suggest that a phenotype-specific approach is needed to treat patients with DTA.

Prevalence and impact of rhinitis in asthma. SACRA, a cross-sectional nation-wide study in Japan

BACKGROUND

Asthma and rhinitis are common co-morbidities everywhere in the world but nation-wide studies assessing rhinitis in asthmatics using questionnaires based on guidelines are not available.

OBJECTIVE

To assess the prevalence, classification, and severity of rhinitis using the Allergic Rhinitis and its Impact on Asthma (ARIA) criteria in Japanese patients with diagnosed and treated asthma.

METHODS

The study was performed from March to August 2009. Patients in physicians' waiting rooms, or physicians themselves, filled out questionnaires on rhinitis and asthma based on ARIA and Global Initiative for Asthma (GINA) diagnostic guides. The patients answered questions on the severity of the diseases and a Visual Analog Scale. Their physicians made the diagnosis of rhinitis.

RESULTS

In this study, 1910 physicians enrolled 29,518 asthmatics; 15,051 (51.0%) questionnaires were administered by physician, and 26,680 (90.4%) patients were evaluable. Self- and physician-administered questionnaires gave similar results. Rhinitis was diagnosed in 68.5% of patients with self-administered questionnaires and 66.2% with physician-administered questionnaires. In this study, 994 (7.6%) patients with self-administered and 561 (5.2%) patients with physician-administered questionnaires indicated rhinitis symptoms on the questionnaires without a physician's diagnosis of rhinitis. Most patients with the physician's diagnosis of rhinitis had moderate/severe rhinitis. Asthma control was significantly impaired in patients with a physician's diagnosis of rhinitis for all GINA clinical criteria except exacerbations. There were significantly more patients with uncontrolled asthma as defined by GINA in those with a physician's diagnosis of rhinitis (25.4% and 29.7%) by comparison with those without rhinitis (18.0% and 22.8%).

CONCLUSION

Rhinitis is common in asthma and impairs asthma control.

Urinary concentrations of 15-epimer of lipoxin A(4) are lower in patients with aspirin-intolerant compared with aspirin-tolerant asthma

BACKGROUND

Although an abnormality in arachidonic acid metabolism may be responsible for aspirin-intolerant asthma (AIA), there is little knowledge about the concentrations of urinary lipoxin A(4) (LXA(4)) and the 15-epimer of LXA(4) (15-epi-LXA(4)) in relation to asthma severity in AIA subjects.

OBJECTIVE

The purpose of this study is to estimate urinary LXA(4) and the 15-epimer concentrations to investigate lipoxins in AIA.

METHODS

In this study, we examined AIA, aspirin-tolerant asthma (ATA) and healthy control groups. The AIA and ATA groups were subdivided into the severe asthma and non-severe asthma subgroups. Urinary LXA(4), 15-epi-LXA(4) and leukotriene E(4) (LTE(4) ) were quantified using enzyme immunoassay after separating these compounds using high-performance liquid chromatography.

RESULTS

The urinary LXA(4) concentration was significantly lower than the 15-epi-LXA(4) concentration in the asthmatic subjects. The AIA group showed significantly lower urinary 15-epi-LXA(4) (P < 0.01) and higher urinary LTE(4) concentrations (P < 0.05) than the ATA group. Comparison of 15-epi-LXA(4) concentrations between the severe asthmatic and non-severe asthmatic subjects in the AIA and ATA groups revealed that the decreased 15-epi-LXA(4) concentration may be related to aspirin intolerance, but not asthma severity. Receiver operator characteristic curves demonstrated that the concentration ratio of LTE(4) to 15-epi-LXA(4) was superior to 15-epi-LXA(4) concentration and LTE(4) concentration as a predictive factor for aspirin intolerance.

CONCLUSIONS AND CLINICAL RELEVANCE

We have demonstrated for the first time that urinary 15-epi-LXA(4) concentration is significantly higher than LXA(4) concentration in both the AIA and ATA groups. 15-Epi-LXA(4) concentration was significantly lower in the AIA group with an increased urinary LTE(4) concentration than in the ATA group. An imbalance between proinflammatory cysteinyl-leukotrienes and anti-inflammatory 15-epi-LXA(4) may be involved in AIA pathogenesis.

Evaluation of translation in the normal and dysplastic hip using three-dimensional magnetic resonance imaging and voxel-based registration

OBJECTIVE

To elucidate in vivo hip instability by comparing normal hips to hips with acetabular dysplasia by evaluating three-dimensional (3D) translations of the femoral head center (FHC) at different hip positions using magnetic resonance imaging (MRI).

DESIGN

Forty normal hips and 22 dysplastic female hips were examined. MRI was performed at four different positions bilaterally: neutral, 45° of flexion, 15° of extension, and the Patrick position. Femoral and pelvic bones were separately extracted at the neutral position and superimposed over the images of each different position using voxel-based registration. The distance between the acetabular center and FHC at neutral position was defined as 3D-migration. The distance between FHC at neutral position and that at each different position was defined as 3D-translation. Two-way repeated measures analysis of variance was performed to consider the dependency between right and left-side data, and multiple linear regression analyses were performed to assess independent relationships.

RESULTS

The center-edge (CE) angle was the determinant for 3D-migration (β=-0.415, P=0.001), and there was a statistical significant difference in 3D-migration between normal female hips and dysplastic hips (P=0.047). From neutral to the Patrick position, the FHC of normal and dysplastic hips translated postero-infero-medially by 1.12±0.39mm (0.45-1.85mm) and 1.97±0.84mm (0.95-4.34mm), respectively, and the difference between the groups was statistically significant (P=0.005). CE angle was the determinant for 3D-translation from neutral to the Patrick position (β=-0.730, P<0.001). The average root mean square error in 3D-translation was 0.172mm and 0.193mm for intra- and interobserver reproducibility, respectively.

CONCLUSIONS

Hip instability was increased in proportion to the severity of acetabular dysplasia. A 3D MRI voxel-based registration technique can show in vivo morphology and kinematics of the native hip without exposure to radioactivity.

Suppression of cAMP-dependent gene expression by cholecystokinin in the hippocampus

Our previous study suggests that "the neuropeptidergic system" might promote a diversity of the mechanisms that regulate signal transmission in the hippocampus. Cholecystokinin (CCK) is the mostly expressed neuropeptide gene in the hippocampus. Here, we investigated whether CCK regulates immediate-early genes (Egr1/zif268 and Fos), critical indicators of cortical neuronal activity. We showed that CCK increased Egr1/zif268 promoter activity in a neuronal cell line, which is transfected with CCK(B) receptor. Unexpectedly, in living hippocampal slices, CCK significantly suppressed cAMP-induced expression of Egr1/zif268 and Fos through CCK(B) receptor activation. This suppression was involved in activating GABA(B) and cannabinoid 1 receptors. In addition to transient CCK modulation of action potentials on hippocampal principal neurons, we suggest that release of endogenous CCK might indirectly produce the suppression of cAMP-dependent gene expression in the hippocampus.

Mouse mandible contains distinctive mesenchymal stem cells

Although human orofacial bone-marrow-derived mesenchymal stem cells showed differentiation traits distinctly different from those of mesenchymal stem cells (MSCs) derived from long bone marrow (BMMSCs), mouse MSCs derived from orofacial bone have not been isolated due to technical difficulties, which in turn precludes the use of mouse models to study and cure orofacial diseases. In this study, we developed techniques to isolate and expand mouse orofacial bone/bone-marrow-derived MSCs (OMSCs) from mandibles and verified their MSC characteristics by single-colony formation, multi-lineage differentiation, and in vivo tissue regeneration. Activated T-lymphocytes impaired OMSCs via the Fas/Fas ligand pathway, as occurs in BMMSCs. Furthermore, we found that OMSCs are distinct from BMMSCs with respect to regulating T-lymphocyte survival and proliferation. Analysis of our data suggests that OMSCs are a unique population of MSCs and play an important role in systemic immunity.

ABBREVIATIONS

BMMSC, bone marrow mesenchymal stem cell; HA/TCP, hydroxyapatite/tricalcium phosphate; OMSC, orofacial mesenchymal stem cell; OVX, ovariectomized.

Transplantation of umbilical cord mesenchymal stem cells alleviates lupus nephritis in MRL/lpr mice

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. This study found that transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) has the same therapeutic effect as transplantation of bone marrow mesenchymal stem cells (BM-MSCs), which has been reported to be efficient in treating SLE-related symptoms in MRL/lpr mice. Multi-treatment (at the 18th, 19th, and 20th weeks of age) of 1 × 10(6) UC-MSCs was able to decrease the levels of 24-h proteinuria, serum creatinine, and anti-double-stranded DNA (dsDNA) antibody, and the extent of renal injury such as crescent formation in MRL/lpr mice. A lower, but still significant, reduction in these parameters was also observed in mice receiving a single dose of UC-MSCs (at the 18th week). UC-MSCs treatment also inhibited expression of monocyte chemotactic protein-1 (MCP-1) and high-mobility group box 1 (HMGB-1) expression in a similar fashion. UC-MSCs labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) were found in the lungs and kidneys 1 week post infusion. In addition, after 11 weeks post UC-MSCs infusion, human cells were found in kidney of UC-MSCs-treated mice. These findings indicated that UC-MSCs transplantation might be a potentially promising approach in the treatment of lupus nephritis, possibly by inhibiting MCP-1 and HMGB-1 production.

Utility of PDL progenitors for in vivo tissue regeneration: a report of 3 cases

OBJECTIVE

Periodontal disease is an inflammatory disorder with widespread morbidities involving both oral and systemic health. The primary goal of periodontal treatment is the regeneration of the lost or diseased periodontium. In this study, we retrospectively examined feasibility and safety of reconstructing the periodontal intrabony defects with autologous periodontal ligament progenitor (PDLP) implantation in three patients.

MATERIALS AND METHODS

In this retrospective pilot study, we treated 16 teeth with at least one deep intrabony defect of probing depth (PD) > OR = 6 mm with PDLP transplantation and evaluated clinical outcome measures in terms of probing depth, gingival recession and attachment gain for a duration of 32-72 months. Furthermore, we compare PDLPs with standard PDL stem cells (PDLSCs) and confirmed that PDLPs possessed progenitor characters.

RESULTS

Clinical examination indicated that transplantationof PDLPs may provide therapeutic benefit for the periodontal defects. All treated patients showed no adverse effects during the entire course of follow up. We also found that PDLPs were analogous to PDLSCs in terms of high proliferation, expression of mesenchymal surface molecules, multipotent differentiation, and in vivo tissue regain. However, PDLPs failed to express scleraxis, a marker of tendon, as seen in PDLSCs.

CONCLUSIONS

This study demonstrated clinical and experimental evidences supporting a potential efficacy and safety of utilizing autologous PDL cells in the treatment of human periodontitis.