• BMB Reports
• /
• v.55 no.7
• /
• pp.336-341
• /
• 2022

Narrowing of arteries supplying blood to the limbs provokes critical hindlimb ischemia (CLI). Although CLI results in irreversible sequelae, such as amputation, few therapeutic options induce the formation of new functional blood vessels. Based on the proangiogenic potentials of stem cells, in this study, it was examined whether a combination of dental pulp stem cells (DPSCs) and human umbilical vein endothelial cells (HUVECs) could result in enhanced therapeutic effects of stem cells for CLI compared with those of DPSCs or HUVECs alone. The DPSCs+ HUVECs combination therapy resulted in significantly higher blood flow and lower ischemia damage than DPSCs or HUVECs alone. The improved therapeutic effects in the DPSCs+ HUVECs group were accompanied by a significantly higher number of microvessels in the ischemic tissue than in the other groups. In vitro proliferation and tube formation assay showed that VEGF in the conditioned media of DPSCs induced proliferation and vessel-like tube formation of HUVECs. Altogether, our results demonstrated that the combination of DPSCs and HUVECs had significantly better therapeutic effects on CLI via VEGF-mediated crosstalk. This combinational strategy could be used to develop novel clinical protocols for CLI proangiogenic regenerative treatments.

• Restorative Dentistry and Endodontics
• /
• v.48 no.1
• /
• pp.9.1-9.11
• /
• 2023

Objectives: This study evaluated the effect of adjacent gingival blood flow on detection of pulpal blood flow (PBF) using ultrasound Doppler flowmetry (UDF) through animal study. Materials and Methods: The study included 36 right and left maxillary the third incisors and canines in 9 experimental dogs. The study included 2 main steps: In the first step, the pulse sound level (PSL) was recorded on the cervical part of each tooth without flap elevation (Group 1), with flap elevation (Group 2), and after it was repositioned in place (Group 3). In the second step, the PSL was recorded on the cervical part of each tooth (Group 4), after pulpotomy (Group 5), after partial pulp extirpation (Group 6), after complete extirpation (Group 7), and after canal filling (Group 8). In Groups 5-8, the study was performed with and without flap elevation in the left and right teeth, respectively. The PSL was graded as follows: 0, inaudible; 1, heard faintly; and 2, heard well. The difference between each group was analyzed using Friedman's test with Wilcoxon signed-rank tests (α = 0.05). Results: In step 1, the PSL results were Group 1 > 2 and 3. In step 2, there was no significant difference between the groups when the flap was not elevated, while PSL results were Group 4 > 5 ≥ 6 and 7 ≥ 8 when the flap was elevated. Conclusions: PBF is affected by gingival blood flow when measured with UDF. UDF measurements require isolation of gingiva from the tooth.

• Restorative Dentistry and Endodontics
• /
• v.30 no.6
• /
• pp.470-476
• /
• 2005

The purpose of this Study was to invest)gate the function or calcitonin gene-related peptide (CGRP) in regulatory mechanism of pulpal microcirculation with the aim of elucidating neurogenic inflammation. Experiments were performed on twelve cats under general anesthesia. CGRP was administered through the femoral vein to see the systemic Influence and through the external carotid artery to see the local effect. Sympathetic nerve to the dental pulp was stimulated electrically and pulpal blood flow (PBF) was measured with a laser Doppler flowmeter on the canine teeth to the drug administration. The paired variables of control and experimental data were compared by paired t-test and differences with p < 0.05 were considered statistically significant. Systemic administration of CGRP $(0.3{\mu}g/ka)$ exerted decreases in systemic blood pressure and caused changes in PBF with an initial increase i311owed by decrease and a move marked second increase and decrease. Close intra-arterial (i.a.) injection of CCRP $(0.03{\mu}g/kg)$ resulted in slight PBF increase. The effect of CGRP resulted in no significant increase in PBF in the presence of $CGRP_{8-37}$. The electrical stimulation of the sympathetic nerve alone resulted in PBF decreases. The j.a. administration of CGRP following the electrical stimulation of the sympathetic nerve compensated the decreased PBF. Therefore, CGRP effectively blocked the sympathetic nerve stimulation-induced PBF decrease. Results of the present study have provided evidences that even though the local vasodilatory function of CGRP are weak, CCRP is effectively involved in blocking the vasoconstriction caused by sympathetic nerve stimulation in the feline dental pulp.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.43 no.2
• /
• pp.158-165
• /
• 2016

The purpose of this study was to analyze photoplethysmographic waveforms from pulse oximeter using raw data of red and infrared light and investigate the reference values of parameters (Height, Width50, Maximum slope, Minimum slope, Area) for evaluating pulpal blood flow in maxillary central incisors with normal pulp vitality in children. The study was performed in 30 pediatric patients, aged 7-16 years old, using pulse oximeter (MEKICS Co., Ltd, Korea) combined with a custom-made sensor. The raw data was obtained and recorded by custom-made software and analyzed by LabChart (v.7.3, ADInstruments, Germany) offline. In this study, we analyzed photoplethysmographic waveforms from pulse oximeter applied to maxillary central incisor for assessment of pulpal blood flow and suggested several reference values of young permanent maxillary central incisor with normal pulp. On average, the waveform of red light was higher, stiffer and wider than that of infrared light. Future studies about reference values for other normal teeth and the teeth with impaired pulp vitality are needed.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.3
• /
• pp.562-568
• /
• 1998

Various diagnostic methods, such as electric pulp test, cold test, test cavity etc., have been used to determine the pulp vitality. At least two or more methods should be used with supplemental information to diagnose each case because using one method doesn't provide sufficient accuracy. These conventional methods have depended on nervous responses, but Laser Doppler Flowmeter determines the pulp vitality by measuring pulpal blood flow. In this case, we tested the vitality of the traumatized teeth with incomplete root apices and autotransplanted teeth with conventional methods and Laser Doppler Flowmeter. Conventional methods, such as electric pulp test and cold test can produce various responses according to the development state of the pulpal nerve and the sensory threshold of the patient. But, Laser Doppler Flowmeter has a lower false response rate than any other pulp vitality test methods and it can determine the vitality somewhat earlier than the other method.

• Restorative Dentistry and Endodontics
• /
• v.27 no.5
• /
• pp.543-551
• /
• 2002

Nitric oxide (NO) is a small molecule (mol. wt. 30 Da) and oxidative free radical. It is uncharged and can therefore diffuse freely within and between cells across membrane. Such characteristics make it a biologically important messenger in physiologic processes such as neurotransmission and the control of vascular tone. NO is also highly toxic and is known to acts as a mediator of cytotoxicity during host defense. NO is synthesized by nitric oxide synthase (NOS) through L-arginine/nitric oxide pathway which is a dioxygenation process. NO synthesis involves several participants, three co-substrates, five electrons, five co-factors and two prosthetic groups. Under normal condition, low levels of NO are synthesized by type I and III NOS for a short period of time and mediates many physiologic processes. Under condition of oxidant stress, high levels of NO are synthesized by type II NOS and inhibits a variety of metabolic processes and can also cause direct damage to DNA. Such interaction result in cytostasis, energy depletion and ultimately cell death. NO has the potential to interact with a variety of intercellular targets producing diverse array of metabolic effects. It is known that NO is involved in hemodynamic regulation, neurogenic inflammation, re-innervation, management of dentin hypersensitivity on teeth. Under basal condition of pulpal blood flow, NO provides constant vasodilator tone acting against sympathetic vasoconstriction. Substance P, a well known vasodilator, was reported to be mediated partly by NO, while calcitonin-gene related peptide has provided no evidence of its relation with NO. This review describes the roles of NO in dental pulp in addition to the known general roles of it.

• Proceedings of the KACD Conference
• /
• 2003.11a
• /
• pp.582-582
• /
• 2003

The purpose of this study was to apply the photoplethsmography(PPG) as a non-invasive tool to evaluate the blood flow of the anterior tooth in clinic. The system consist of two light-emitting diodes(LED) powered by 5V as the light source. The LED was designed to two weve lengths, 940(infrared) and 660(red)nm simultaneously with a 36nm bandwidth at half the peak intensity. The 54 anterior vital tooth were examined and the measured was analysed in frequency domian (power spectrum).(omitted)

• Journal of the korean academy of Pediatric Dentistry
• /
• v.26 no.2
• /
• pp.437-445
• /
• 1999

The purpose of this study was to evaluate the changes of laser doppler flowmeter output associated with stage of root development. Laser Doppler Flowmeter was done in 40 elementary students aged between 7 and 8 years and in 20 adults aged between 23 and 24 years. Among 40 elementary students, 20 had apical foramens with $1{\sim}2mm$ diameters and another 20 had ones with larger diameters than 2mm. The LDF values were analyzed with ANOVA and paired t-test. The results were as follows. 1. Immature root apecies group had a higher tendency than mature root apecies group in LDF values, but there was no statistical significance (p>0.05). 2. There was no statistical significance in LDF values comparing groups with immature root apecies (p>0.05). 3. There were no significant differences between right and left central incisors in LDF values (p>0.05).

• Archives of Plastic Surgery
• /
• v.49 no.1
• /
• pp.61-69
• /
• 2022

Background Single free flaps are a commonly used reconstructive method for multiple soft tissue defects in digits. We analyzed the flap size, division timing, and degree of necrosis in cases with various types of flap division. Methods We conducted a retrospective review of the medical charts of patients who had undergone single free flap reconstruction for multiple soft tissue defects across their digits from 2011 to 2020. The flap types included were the lateral arm free flap, venous forearm free flap, thenar free flap, hypothenar free flap, anterolateral thigh free flap, medial plantar free flap, and second toe pulp free flap. Flap size, anastomosed vessels, division timing, and occurrence of flap necrosis were retrospectively investigated and then analyzed using the t-test. Results In total, 75 patients were included in the analysis. The success rate of the free flaps was 97.3%. All flaps were successfully divided after at least 17 days, with a mean of 47.17 days (range, 17-243 days) for large flaps and 42.81 days (range, 20-130 days) for the medium and small flaps (P=0.596). The mean area of flap necrosis was 2.38% in the large flaps and 2.58% in the medium and small flaps (P=0.935). Severe necrosis of the divided flap developed in two patients who had undergone flap division at week 6 and week 34. Conclusions In cases where blood flow to the flap has been stable for more than 3 weeks, flap division can be safely attempted regardless of the flap size.

• The Korean Journal of Pharmacology
• /
• v.24 no.1
• /
• pp.63-70
• /
• 1988

Alterations in splanchnic circulatory hemodynamics along with reactivities to the alpha adrenoceptor agonists were assessed in association with the preventive effects of propranolol 10 days after portal ligation. Decreases in precapillary resistance (Ra) and postcapillary resistance (Rv) along with increases in mesenteric blood flow (MBF) and capillary pressure (CP) were observed in conjunction with an increment of splenic pulp pressure (SPP). Dose-dependent increase in Rv in response to noradrenaline, increases in Ra and RV to adrenaline, and increases in superior mesenteric arterial pressure (SMAP), Ra and Rv to phenylephrine observed in sham group were significantly attenuated by portal vein stenosis. In PPL-3 group (propranolol 3 mg/kg, i.p. three times daily for 10 days), MBF was significantly decreased in association with decrease in mesenteric venous pressure (MVP) when compared with those of protal ligated (PL) group, and decreased Ra and Rv in PL group were recovered toward the values of sham group. Likewise, in PPL-1 group (propranolol 5 mg/kg, i.p. once daily for 10 days), the pressor response of Rv to adrenaline was recovered up to the level of sham group. Thus, it is suggested that decreases in Ra and Rv in association with increases in MBF and CP may have a close relevance to the increased SPP, and the changes in circulatory hemodynamics and vascular reactivities were effectively reversed by longterm propranolol treatment. Based on these results, it is concluded that these changes observed in portal hypertension are closely related with the altered functions of the adrenoceptors in the splanchnic vascular beds.